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Versions: (draft-wen-l2sm-l2vpn-service-model) 00 01 02 03 04 05 06 07 08 09 10

L2SM Working Group                                                B. Wen
Internet-Draft                                                   Comcast
Intended status: Standards Track                        G. Fioccola, Ed.
Expires: October 13, 2018                                 Telecom Italia
                                                                  C. Xie
                                                           China Telecom
                                                                L. Jalil
                                                                 Verizon
                                                          April 11, 2018


              A YANG Data Model for L2VPN Service Delivery
                 draft-ietf-l2sm-l2vpn-service-model-10

Abstract

   This document defines a YANG data model that can be used to configure
   a Layer 2 Provider Provisioned VPN service.  It is up to a management
   system to take this as an input and generate specific configurations
   models to configure the different network elements to deliver the
   service.  How configuration of network elements is done is out of
   scope of the document.

   The YANG model in this document includes support for point-to-point
   Virtual Private Wire Services (VPWS) and multipoint Virtual Private
   LAN services (VPLS) that use Pseudowires signaled using the Label
   Distribution Protocol (LDP) and the Border Gateway Protocol (BGP) as
   described in RFC4761 and RFC6624.

   The YANG model in this document conforms to the Network Management
   Datastore Architecture defined in RFC8342.

Status of This Memo

   This Internet-Draft is submitted in full conformance with the
   provisions of BCP 78 and BCP 79.

   Internet-Drafts are working documents of the Internet Engineering
   Task Force (IETF).  Note that other groups may also distribute
   working documents as Internet-Drafts.  The list of current Internet-
   Drafts is at https://datatracker.ietf.org/drafts/current/.

   Internet-Drafts are draft documents valid for a maximum of six months
   and may be updated, replaced, or obsoleted by other documents at any
   time.  It is inappropriate to use Internet-Drafts as reference
   material or to cite them other than as "work in progress."

   This Internet-Draft will expire on October 13, 2018.



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Copyright Notice

   Copyright (c) 2018 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

   This document is subject to BCP 78 and the IETF Trust's Legal
   Provisions Relating to IETF Documents
   (https://trustee.ietf.org/license-info) in effect on the date of
   publication of this document.  Please review these documents
   carefully, as they describe your rights and restrictions with respect
   to this document.  Code Components extracted from this document must
   include Simplified BSD License text as described in Section 4.e of
   the Trust Legal Provisions and are provided without warranty as
   described in the Simplified BSD License.

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   3
     1.1.  Terminology . . . . . . . . . . . . . . . . . . . . . . .   4
       1.1.1.  Requirements Language . . . . . . . . . . . . . . . .   5
     1.2.  Tree diagram  . . . . . . . . . . . . . . . . . . . . . .   5
   2.  Definitions . . . . . . . . . . . . . . . . . . . . . . . . .   5
   3.  The Layer 2 VPN Service Model . . . . . . . . . . . . . . . .   6
     3.1.  Layer 2 VPN Service Types . . . . . . . . . . . . . . . .   7
     3.2.  Layer 2 VPN Physical Network Topology . . . . . . . . . .   7
   4.  Service Data Model Usage  . . . . . . . . . . . . . . . . . .   9
   5.  Design of the Data Model  . . . . . . . . . . . . . . . . . .  11
     5.1.  Features and Augmentation . . . . . . . . . . . . . . . .  20
     5.2.  VPN Service Overview  . . . . . . . . . . . . . . . . . .  20
       5.2.1.  VPN Service Type  . . . . . . . . . . . . . . . . . .  21
       5.2.2.  VPN Service Topology  . . . . . . . . . . . . . . . .  22
         5.2.2.1.  Route Target Allocation . . . . . . . . . . . . .  22
         5.2.2.2.  Any-to-Any  . . . . . . . . . . . . . . . . . . .  22
         5.2.2.3.  Hub-and-Spoke . . . . . . . . . . . . . . . . . .  22
         5.2.2.4.  Hub-and-Spoke-Disjoint  . . . . . . . . . . . . .  23
       5.2.3.  Cloud Access  . . . . . . . . . . . . . . . . . . . .  24
       5.2.4.  Extranet VPNs . . . . . . . . . . . . . . . . . . . .  26
       5.2.5.  Frame Delivery Service  . . . . . . . . . . . . . . .  28
     5.3.  Site Overview . . . . . . . . . . . . . . . . . . . . . .  29
       5.3.1.  Devices and Locations . . . . . . . . . . . . . . . .  30
       5.3.2.  Site Network Accesses . . . . . . . . . . . . . . . .  31
         5.3.2.1.  Bearer  . . . . . . . . . . . . . . . . . . . . .  32
         5.3.2.2.  Connection  . . . . . . . . . . . . . . . . . . .  32
     5.4.  Site Role . . . . . . . . . . . . . . . . . . . . . . . .  37
     5.5.  Site Belonging to Multiple VPNs . . . . . . . . . . . . .  37
       5.5.1.  Site VPN Flavor . . . . . . . . . . . . . . . . . . .  37
         5.5.1.1.  Single VPN Attachment: site-vpn-flavor-single . .  37
         5.5.1.2.  MultiVPN Attachment: site-vpn-flavor-multi  . . .  38



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         5.5.1.3.  NNI: site-vpn-flavor-nni  . . . . . . . . . . . .  38
         5.5.1.4.  E2E: site-vpn-flavor-e2e  . . . . . . . . . . . .  39
       5.5.2.  Attaching a Site to a VPN . . . . . . . . . . . . . .  40
         5.5.2.1.  Referencing a VPN . . . . . . . . . . . . . . . .  40
         5.5.2.2.  VPN Policy  . . . . . . . . . . . . . . . . . . .  42
     5.6.  Deciding Where to Connect the Site  . . . . . . . . . . .  47
       5.6.1.  Constraint: Device  . . . . . . . . . . . . . . . . .  47
       5.6.2.  Constraint/Parameter: Site Location . . . . . . . . .  48
       5.6.3.  Constraint/Parameter: Access Type . . . . . . . . . .  49
       5.6.4.  Constraint: Access Diversity  . . . . . . . . . . . .  50
     5.7.  Route Distinguisher and Network Instance Allocation . . .  51
     5.8.  Site Network Access Availability  . . . . . . . . . . . .  52
     5.9.  SVC MTU . . . . . . . . . . . . . . . . . . . . . . . . .  53
     5.10. Service . . . . . . . . . . . . . . . . . . . . . . . . .  54
       5.10.1.  Bandwidth  . . . . . . . . . . . . . . . . . . . . .  54
       5.10.2.  QoS  . . . . . . . . . . . . . . . . . . . . . . . .  55
         5.10.2.1.  QoS Classification . . . . . . . . . . . . . . .  55
         5.10.2.2.  QoS Profile  . . . . . . . . . . . . . . . . . .  56
       5.10.3.  Broadcast Multicast Unknow Unicast Support . . . . .  57
     5.11. Site Management . . . . . . . . . . . . . . . . . . . . .  58
     5.12. MAC Loop Protection . . . . . . . . . . . . . . . . . . .  58
     5.13. MAC Address Limit . . . . . . . . . . . . . . . . . . . .  59
     5.14. Enhanced VPN Features . . . . . . . . . . . . . . . . . .  59
       5.14.1.  Carriers' Carriers . . . . . . . . . . . . . . . . .  59
     5.15. External ID References  . . . . . . . . . . . . . . . . .  61
     5.16. Defining NNIs and Inter-AS support  . . . . . . . . . . .  61
       5.16.1.  Defining an NNI with the Option A Flavor . . . . . .  63
       5.16.2.  Defining an NNI with the Option B Flavor . . . . . .  66
       5.16.3.  Defining an NNI with the Option C Flavor . . . . . .  68
     5.17. Applicability of L2SM model in Inter-Provider and Inter-
           Domain Orchestration  . . . . . . . . . . . . . . . . . .  70
   6.  Interaction with Other YANG Modules . . . . . . . . . . . . .  71
   7.  Service Model Usage Example . . . . . . . . . . . . . . . . .  72
   8.  YANG Module . . . . . . . . . . . . . . . . . . . . . . . . .  78
   9.  Security Considerations . . . . . . . . . . . . . . . . . . . 147
   10. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 148
   11. Acknowledgements  . . . . . . . . . . . . . . . . . . . . . . 149
   12. References  . . . . . . . . . . . . . . . . . . . . . . . . . 149
     12.1.  Normative References . . . . . . . . . . . . . . . . . . 149
     12.2.  Informative References . . . . . . . . . . . . . . . . . 151
   Appendix A.  Changes Log  . . . . . . . . . . . . . . . . . . . . 153
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . . 156

1.  Introduction

   This document defines a YANG data model for Layer 2 VPN (L2VPN)
   service.  This model defines service configuration elements that can
   be used in communication protocols between customers and network



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   operators.  Those elements can also be used as input to automated
   control and configuration applications and and generate specific
   configurations models to configure the different network elements to
   deliver the service.  How configuration of network elements is done
   is out of scope of the document.

   Further discussion of the way that services are modeled in YANG and
   the relationship between "customer service models" like the one
   described in this document and configuration models can be found in
   [RFC8309] and [RFC8199].  Section 4 and Section 6 also provide more
   information of how this service model could be used and how it fits
   into the overall modeling architecture.

   The YANG model in this document includes support for point-to-point
   Virtual Private Wire Services (VPWS) and multipoint Virtual Private
   LAN services (VPLS) that use Pseudowires signaled using the Label
   Distribution Protocol (LDP) and the Border Gateway Protocol (BGP) as
   described in [RFC4761] and [RFC6624].  It also conforms to the
   Network Management Datastore Architecture (NMDA) [RFC8342].

1.1.  Terminology

   The following terms are defined in [RFC6241] and are not redefined
   here:

   o  client

   o  configuration data

   o  server

   o  state data

   The following terms are defined in [RFC7950] and are not redefined
   here:

   o  augment

   o  data model

   o  data node

   The terminology for describing YANG data models is found in
   [RFC7950].







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1.1.1.  Requirements Language

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
   "OPTIONAL" in this document are to be interpreted as described in BCP
   14 [RFC2119] [RFC8174] when, and only when, they appear in all
   capitals, as shown here.

1.2.  Tree diagram

   Tree diagrams used in this document follow the notation defined in
   [RFC8340].

2.  Definitions

   This document uses the following terms:

   Service Provider (SP):  The organization (usually a commercial
      undertaking) responsible for operating the network that offers VPN
      services to clients and customers.

   Customer Edge (CE) Device:  Equipment that is dedicated to a
      particular customer and is directly connected to one or more PE
      devices via attachment circuits.  A CE is usually located at the
      customer premises, and is usually dedicated to a single VPN,
      although it may support multiple VPNs if each one has separate
      attachment circuits.  The CE devices can be routers, bridges,
      switches, or hosts.

   Provider Edge (PE) Device:  Equipment managed by the SP that can
      support multiple VPNs for different customers, and is directly
      connected to one or more CE devices via attachment circuits.  A PE
      is usually located at an SP point of presence (PoP) and is managed
      by the SP.

   Virtual Private LAN Service (VPLS):  A VPLS is a provider service
      that emulates the full functionality of a traditional Local Area
      Network (LAN).  A VPLS makes it possible to interconnect several
      LAN segments over a packet switched network (PSN) and makes the
      remote LAN segments behave as one single LAN.

   Virtual Private Wire Service (VPWS):  A VPWS is a point-to-point
      circuit (i.e., link) connecting two CE devices.  The link is
      established as a logical Layer 2 circuit through a packet switched
      network.  The CE in the customer network is connected to a PE in
      the provider network via an Attachment Circuit (AC): the AC is
      either a physical or a logical circuit.  A VPWS differs from a
      VPLS in that the VPLS is point-to-multipoint, while the VPWS is



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      point-to-point.  In some implementations, a set of VPWSs is used
      to create a multi-site L2VPN network.

   Pseudowire(PW):  A pseudowire is an emulation of a native service
      over a packet switched network (PSN).  The native service may be
      ATM, frame relay, Ethernet, low-rate TDM, or SONET/SDH, while the
      PSN may be MPLS, IP (either IPv4 or IPv6), or L2TPv3.

   MAC-VRF:  A Virtual Routing and Forwarding table for Media Access
      Control (MAC) addresses on a PE.  It is sometime also referred to
      as a Virtual Switching Instance (VSI).

   UNI:  User to Network Interface.  The physical demarcation point
      between the responsibility of Customer and the responsibility of
      Provider.

   NNI:  Network to Network Interface.  A reference point representing
      the boundary between two Networks that are operated as separate
      administrative domains.  The two networks may belong to the same
      provider or to two different providers.

   This document uses the following abbreviations:

   BSS:  Business Support System

   BUM:  Broadcast-UnknownUnicast-Multicast

   CoS:  Class of Service

   LAG:  Link Aggregation Group

   LLDP:  Link Level Discovery Protocol

   OAM:  Operations, Administration, and Maintenance

   OSS:  Operations Support System

   PDU:  Protocol Data Unit

   QoS:  Quality of Service

3.  The Layer 2 VPN Service Model

   A Layer 2 VPN (L2VPN) service is a collection of sites that are
   authorized to exchange traffic between each other over a shared
   infrastructure of a common technology.  This L2VPN service model
   (L2SM) provides a common understanding of how the corresponding L2VPN
   service is to be deployed over the shared infrastructure.



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   This document presents the L2SM using the YANG data modeling language
   [RFC7950] as a formal language that is both human-readable and
   parsable by software for use with protocols such as NETCONF [RFC6241]
   and RESTCONF [RFC8040].

   This service model is limited to VPWS and VPLS based VPNs as
   described in [RFC4761] and [RFC6624], EVPN as described in [RFC7432].

3.1.  Layer 2 VPN Service Types

   From a technology perspective, a set of basic L2VPN service types
   include:

   o  Point-to-point Virtual Private Wire Services (VPWSs) that use LDP-
      signaled Pseudowires or L2TP-signaled Pseudowires [RFC6074];

   o  Multipoint Virtual Private LAN Services (VPLSs) that use LDP-
      signaled Pseudowires or L2TP-signaled Pseudowires [RFC6074];

   o  Multipoint Virtual Private LAN Services (VPLSs) that use a Border
      Gateway Protocol (BGP) control plane as described in [RFC4761] and
      [RFC6624];

   o  IP-Only LAN-Like Services (IPLSs) that are a functional subset of
      VPLS services [RFC7436];

   o  BGP MPLS-based Ethernet VPN Services as described in [RFC7432] and
      [RFC7209];

   o  Ethernet VPN VPWS specified in [RFC8214] and [RFC7432];

3.2.  Layer 2 VPN Physical Network Topology

   Figure 1 depicts a typical service provider's physical network
   topology.  Most service providers have deployed an IP, MPLS, or
   Segment Routing (SR) multi-service core infrastructure.  Ingress
   Layer 2 service frames will be mapped to either an Ethernet
   Pseudowire (PWE) or a VXLAN PE-to-PE tunnel.  The details of these
   tunneling mechanism are at the provider's discretion and not part of
   the L2SM.

   An L2VPN provides end-to-end L2 connectivity over this multi-service
   core infrastructure between two or more customer locations or a
   collection of sites.  Attachment Circuits are placed between CE
   devices and PE Devices that backhaul layer 2 service frames from the
   customer over the access network to the Provider Network or remote
   Site.  The demarcation point (i.e., UNI) between the customer and
   service provider can be either placed between Customer nodes and the



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   Customer Edge Device, or between the Customer Edge Device and the
   Provider Edge Device.  The actual bearer connection between CE and PE
   will be described in the L2SM model.

   The service provider may also choose a Seamless MPLS approach to
   expand the PWE or VXLAN tunnel between sites.

   The service provider may leverage multi-protocol BGP to auto-discover
   and signal the PWE or VXLAN tunnel end points.

             Site A  |                          |Site B
    ---     ----     |        VXLAN/PW          |               ---
   |   |   |    |    |<------------------------>|              |   |
   | C +---+ CE |    |                          |              | C |
   |   |   |    |    |         ---------        |              |   |
    ---     ----\    |        (         )       |              /---
                 \  -|--     (           )     -|--     ----  /
                  \|    |   (             )   |    |   |    |/
                   | PE +---+ IP/MPLS/SR  +---+ PE +---+ CE |
                  /|    |   (  Network    )   |    |   |    |\
                 /  ----     (           )     ----     ----  \
    ---     ----/             (         )                      \---
   |   |   |    |              ----+----                       |   |
   | C +---+ CE |                  |                           | C |
   |   |   |    |                --+--                         |   |
    ---     ----                | PE  |                         ---
                                 --+--
                                   |      Site C
                                 --+--
                                | CE  |
                                 --+--
                                   |
                                 --+--
                                |  C  |
                                 -----

    Figure 1: Reference Network for the Use of the L2VPN Service Model

   From the customer perspective, however, all the customer edge devices
   are connected over a simulated LAN environment as shown in Figure 2.
   Broadcast and multicast packets are sent to all participants in the
   same bridge domain.









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                        CE---+----+-----+---CE
                             |    |     |
                             |    |     |
                             |    |     |
                        CE---+    CE    +---CE

                   Figure 2: Customer View of the L2VPN

4.  Service Data Model Usage

   The L2VPN service model provides an abstracted interface to request,
   configure, and manage the components of an L2VPN service.  The model
   is used by a customer who purchases connectivity and other services
   from an SP to communicate with that SP.

   A typical usage for this model is as an input to an orchestration
   layer that is responsible for translating it into configuration
   commands for the network elements that deliver/enable the service.
   The network elements may be routers, but also servers (like AAA) that
   are necessary within the network.

   The configuration of network elements may be done using the Command
   Line Interface (CLI), or any other configuration (or "southbound")
   interface such as NETCONF [RFC6241] in combination with device-
   specific and protocol-specific YANG models.

   This way of using the service model is illustrated in Figure 3 and
   described in more detail in [RFC8309] and [RFC8199].  The split of
   the orchestration function between a "Service Orchestrator" and a
   "Network Orchestrator" is clarified in [RFC8309].  The usage of this
   service model is not limited to this example: it can be used by any
   component of the management system, but not directly by network
   elements.

   The usage and structure of this model should be compared to the Layer
   3 VPN service model defined in [RFC8299].















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          ----------------------------
         | Customer Service Requester |
          ----------------------------
              |
      L2VPN   |
      Service |
      Model   |
              |
            -----------------------
           | Service Orchestration |
            -----------------------
              |
              |     Service             +-------------+
              |     Delivery    +------>| Application |
              |     Model       |       |   BSS/OSS   |
              |                 V       +-------------+
            -----------------------
           | Network Orchestration |
            -----------------------
              |            |
      +----------------+   |
      | Config manager |   |
      +----------------+   |  Device
              |            |  Models
              |            |
   --------------------------------------------
                     Network
                                 +++++++
                                 + AAA +
                                 +++++++

         ++++++++   Bearer    ++++++++           ++++++++      ++++++++
         + CE A + ----------- + PE A +           + PE B + ---- + CE B +
         ++++++++  Connection ++++++++           ++++++++      ++++++++

                    Site A                               Site B

     Figure 3: Reference Architecture for the Use of the L2VPN Service
                                   Model

   The MEF Forum (MEF) has also developed an architecture for network
   management and operation, but the work of the MEF embraces all
   aspects of Lifecycle Service Orchestration, including billing, SLAs,
   order management, and lifecycle management.  The IETF's work on
   service models is typically smaller and offers a simple, self-
   contained service YANG module.  See more details in [RFC8309].





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5.  Design of the Data Model

   The L2SM model is structured in a way that allows the provider to
   list multiple circuits of various service types for the same
   customer.  A circuit represents an end-to-end connection between two
   or more locations of Customers.

   The YANG module is divided into two main containers: vpn-services and
   sites.  The vpn-svc container under vpn-services defines global
   parameters for the VPN service for a specific customer.

   A site contains at least one network access (i.e., site network
   accesses providing access to the sites defined in Section 5.3.2) and
   there may be multiple network accesses in case of multihoming.  The
   site to network access attachment is done through a bearer with a
   Layer 2 connection on top.  The bearer refers to properties of the
   attachment that are below layer 2 while the connection refers to
   layer 2 protocol oriented properties.  The bearer may be allocated
   dynamically by the service provider and the customer may provide some
   constraints or parameters to drive the placement.

   Authorization of traffic exchange is done through what we call a VPN
   policy or VPN topology defining routing exchange rules between sites.

   An end to end Multi-segment connectivity can be realized using a
   combination of per site connectivity and per segment connectivity at
   different segments.

   The figure below describe the overall structure of the YANG module:

   module: ietf-l2vpn-svc
   +--rw l2vpn-svc
     +--rw vpn-profiles
     |  +--rw valid-provider-identifiers
     |     +--rw cloud-identifier*  string{cloud-access}?
     |     +--rw qos-profile-identifier* string
     |     +--rw bfd-profile-identifier* string
     |     +--rw remote-carrier-identifier* string
     +--rw vpn-services
     |  +--rw vpn-service* [vpn-id]
     |     +--rw vpn-id                      svc-id
     |     +--rw vpn-svc-type?               identityref
     |     +--rw customer-name?              string
     |     +--rw svc-topo?                   identityref
     |     +--rw cloud-accesses {cloud-access}?
     |     |  +--rw cloud-access* [cloud-identifier]
     |     |     +--rw cloud-identifier
     |     |     |    -> /l2vpn-svc/vpn-profiles/



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     |     |     |      valid-provider-identifiers/cloud-identifier
     |     |     +--rw (list-flavor)?
     |     |        +--:(permit-any)
     |     |        |  +--rw permit-any?         empty
     |     |        +--:(deny-any-except)
     |     |        |  +--rw permit-site*
     |     |        |  :    -> /l2vpn-svc/sites/site/site-id
     |     |        +--:(permit-any-except)
     |     |           +--rw deny-site*
     |     |                -> /l2vpn-svc/sites/site/site-id
     |     +--rw frame-delivery {frame-delivery}?
     |     |  +--rw customer-tree-flavors
     |     |  |  +--rw tree-flavor*   identityref
     |     |  +--rw bum-frame-delivery
     |     |  |  +--rw bum-frame-delivery* [frame-type]
     |     |  |     +--rw frame-type       identityref
     |     |  |     +--rw delivery-mode?   identityref
     |     |  +--rw multicast-gp-port-mapping    identityref
     |     +--rw extranet-vpns {extranet-vpn}?
     |     |  +--rw extranet-vpn* [vpn-id]
     |     |     +--rw vpn-id              svc-id
     |     |     +--rw local-sites-role?   identityref
     |     +--rw ce-vlan-preservation        boolean
     |     +--rw ce-vlan-cos-preservation    boolean
     |     +--rw carrierscarrier?            boolean {carrierscarrier}?
     +--rw sites
       +--rw site* [site-id]
        +--rw site-id                                string
        +--rw site-vpn-flavor?                       identityref
        +--rw devices
        |  +--rw device* [device-id]
        |     +--rw device-id     string
        |     +--rw location
        |     |    -> ../../../locations/location/location-id
        |     +--rw management
        |        +--rw transport?   identityref
        |        +--rw address?     inet:ip-address
        +--rw management
        |  +--rw type    identityref
        +--rw locations
        |  +--rw location* [location-id]
        |     +--rw location-id     string
        |     +--rw address?        string
        |     +--rw postal-code?       string
        |     +--rw state?          string
        |     +--rw city?           string
        |     +--rw country-code?   string
        +--rw site-diversity {site-diversity}?



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        |  +--rw groups
        |     +--rw group* [group-id]
        |        +--rw group-id    string
        +--rw vpn-policies
        |  +--rw vpn-policy* [vpn-policy-id]
        |     +--rw vpn-policy-id    string
        |     +--rw entries* [id]
        |        +--rw id         string
        |        +--rw filters
        |        |  +--rw filter* [type]
        |        |     +--rw type       identityref
        |        |     +--rw lan-tag*   uint32 {lan-tag}?
        |        +--rw vpn* [vpn-id]
        |           +--rw vpn-id
        |           |    -> /l2vpn-svc/vpn-services/
        |           |            vpn-service/vpn-id
        |           +--rw site-role?   identityref
        +--rw service
        |  +--rw qos {qos}?
        |  |  +--rw classification-policy
        |  |  |  +--rw rule* [id]
        |  |  |     +--rw id                   string
        |  |  |     +--rw (match-type)?
        |  |  |     |  +--:(match-flow)
        |  |  |     |  |  +--rw match-flow
        |  |  |     |  |     +--rw dscp?           inet:dscp
        |  |  |     |  |     +--rw dot1q?          uint16
        |  |  |     |  |     +--rw pcp?            uint8
        |  |  |     |  |     +--rw src-mac?        yang:mac-address
        |  |  |     |  |     +--rw dst-mac?        yang:mac-address
        |  |  |     |  |     +--rw color-type?     identityref
        |  |  |     |  |     +--rw target-sites*
        |  |  |     |  |     |               svc-id {target-sites}?
        |  |  |     |  |     +--rw any?            empty
        |  |  |     |  |     +--rw vpn-id?         svc-id
        |  |  |     |  +--:(match-application)
        |  |  |     |     +--rw match-application?   identityref
        |  |  |     +--rw target-class-id?     string
        |  |  +--rw qos-profile
        |  |     +--rw (qos-profile)?
        |  |        +--:(standard)
        |  |        |  +--rw profile?
        |  |        |       -> /l2vpn-svc/vpn-profiles/
        |  |        |              valid-provider-identifiers/
        |  |        |              qos-profile-identifier
        |  |        +--:(custom)
        |  |           +--rw classes {qos-custom}?
        |  |              +--rw class* [class-id]



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        |  |                 +--rw class-id        string
        |  |                 +--rw direction?      identityref
        |  |                 +--rw policing?       identityref
        |  |                 +--rw byte-offset?    uint16
        |  |                 +--rw frame-delay
        |  |                 |  +--rw (flavor)?
        |  |                 |     +--:(lowest)
        |  |                 |     |  +--rw use-lowest-latency? empty
        |  |                 |     +--:(boundary)
        |  |                 |        +--rw delay-bound?     uint16
        |  |                 +--rw frame-jitter
        |  |                 |  +--rw (flavor)?
        |  |                 |     +--:(lowest)
        |  |                 |     |  +--rw use-lowest-jitter? empty
        |  |                 |     +--:(boundary)
        |  |                 |        +--rw delay-bound?     uint32
        |  |                 +--rw frame-loss
        |  |                 |  +--rw rate?   decimal64
        |  |                 +--rw bandwidth
        |  |                    +--rw guaranteed-bw-percent decimal64
        |  |                    +--rw end-to-end?           empty
        |  +--rw carrierscarrier {carrierscarrier}?
        |     +--rw signaling-type?   identityref
        +--rw broadcast-unknown-unicast-multicast {bum}?
        |  +--rw multicast-site-type?            enumeration
        |  +--rw multicast-gp-address-mapping* [id]
        |  |  +--rw id                 uint16
        |  |  +--rw vlan-id            uint16
        |  |  +--rw mac-gp-address     yang:mac-address
        |  |  +--rw port-lag-number?   uint32
        |  +--rw bum-overall-rate?     uint32
        |  +--rw bum-rate-per-type* [type]
        |     +--rw type    identityref
        |     +--rw rate?   uint32
        +--rw mac-loop-prevention {mac-loop-prevention}?
        |  +--rw protection-type?   identityref
        |  +--rw frequency?         uint32
        |  +--rw retry-timer?       uint32
        +--rw access-control-list
        |  +--rw mac* [mac-address]
        |     +--rw mac-address    yang:mac-address
        +--ro actual-site-start?   yang:date-and-time
        +--ro actual-site-stop?    yang:date-and-time
        +--rw bundling-type?       identityref
        +--rw default-ce-vlan-id   uint32
        +--rw site-network-accesses
           +--rw site-network-access* [network-access-id]
           +--rw network-access-id                 string



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           +--rw remote-carrier-name?              string
           +--rw type?                             identityref
           +--rw (location-flavor)
           |  +--:(location)
           |  |  +--rw location-reference?
           |  |       -> ../../../locations/location/
           |  |               location-id
           |  +--:(device)
           |     +--rw device-reference?
           |          -> ../../../devices/device/device-id
           +--rw access-diversity {site-diversity}?
           |  +--rw groups
           |  |  +--rw group* [group-id]
           |  |     +--rw group-id    string
           |  +--rw constraints
           |     +--rw constraint* [constraint-type]
           |        +--rw constraint-type    identityref
           |        +--rw target
           |           +--rw (target-flavor)?
           |              +--:(id)
           |              |  +--rw group* [group-id]
           |              |     +--rw group-id    string
           |              +--:(all-accesses)
           |              |  +--rw all-other-accesses?   empty
           |              +--:(all-groups)
           |                 +--rw all-other-groups?     empty
           +--rw bearer
           |  +--rw requested-type {requested-type}?
           |  |  +--rw type?     string
           |  |  +--rw strict?   boolean
           |  +--rw always-on?         boolean {always-on}?
           |  +--rw bearer-reference?  string {bearer-reference}?
           +--rw connection
           |  +--rw encapsulation-type?    identityref
           |  +--rw eth-inf-type?          identityref
           |  +--rw tagged-interface
           |  |  +--rw type?               identityref
           |  |  +--rw dot1q-vlan-tagged {dot1q}?
           |  |  |  +--rw tg-type?    identityref
           |  |  |  +--rw cvlan-id    uint16
           |  |  +--rw priority-tagged
           |  |  |  +--rw tag-type?   identityref
           |  |  +--rw qinq {qinq}?
           |  |  |  +--rw tag-type?   identityref
           |  |  |  +--rw svlan-id    uint16
           |  |  |  +--rw cvlan-id    uint16
           |  |  +--rw qinany {qinany}?
           |  |  |  +--rw tag-type?   identityref



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           |  |  |  +--rw svlan-id    uint16
           |  |  +--rw vxlan {vxlan}?
           |  |     +--rw vni-id       uint32
           |  |     +--rw peer-mode?   identityref
           |  |     +--rw peer-list* [peer-ip]
           |  |        +--rw peer-ip    inet:ip-address
           |  +--rw untagged-interface
           |  |  +--rw speed?                 uint32
           |  |  +--rw mode?                  neg-mode
           |  |  +--rw phy-mtu?               uint32
           |  |  +--rw lldp?                  boolean
           |  |  +--rw oam-802.3ah-link {oam-3ah}?
           |  |  |  +--rw enable?   boolean
           |  |  +--rw uni-loop-prevention?   boolean
           |  +--rw lag-interfaces {lag-interface}?
           |  |  +--rw lag-interface* [index]
           |  |     +--rw index    string
           |  |     +--rw lacp {lacp}?
           |  |        +--rw enable?            boolean
           |  |        +--rw mode?              neg-mode
           |  |        +--rw speed?             uint32
           |  |        +--rw mini-link-num?     uint32
           |  |        +--rw system-priority?   uint16
           |  |        +--rw micro-bfd {micro-bfd}?
           |  |        |  +--rw enable?       enumeration
           |  |        |  +--rw interval?     uint32
           |  |        |  +--rw hold-timer?   uint32
           |  |        +--rw bfd {bfd}?
           |  |        |  +--rw enabled?        boolean
           |  |        |  +--rw (holdtime)?
           |  |        |     +--:(profile)
           |  |        |     |  +--rw profile-name?
           |  |        |     |    -> /l2vpn-svc/
           |  |        |     |         vpn-profiles/
           |  |        |     |        valid-provider-identifiers/
           |  |        |     |       bfd-profile-identifier
           |  |        |     +--:(fixed)
           |  |        |        +--rw fixed-value?    uint32
           |  |        +--rw member-links
           |  |        |  +--rw member-link* [name]
           |  |        |     +--rw name                string
           |  |        |     +--rw speed?              uint32
           |  |        |     +--rw mode?               neg-mode
           |  |        |     +--rw link-mtu?           uint32
           |  |        |     +--rw oam-802.3ah-link {oam-3ah}?
           |  |        |        +--rw enable?   boolean
           |  |        +--rw flow-control?      boolean
           |  |        +--rw lldp?              boolean



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           |  +--rw cvlan-id-to-svc-map* [svc-id]
           |  |  +--rw svc-id
           |  |  |    -> /l2vpn-svc/vpn-services/vpn-service/
           |  |  |           vpn-id
           |  |  +--rw cvlan-id* [vid]
           |  |     +--rw vid    uint16
           |  +--rw l2cp-control {l2cp-control}?
           |  |  +--rw stp-rstp-mstp?    control-mode
           |  |  +--rw pause?            control-mode
           |  |  +--rw lacp-lamp?        control-mode
           |  |  +--rw link-oam?         control-mode
           |  |  +--rw esmc?             control-mode
           |  |  +--rw l2cp-802.1x?      control-mode
           |  |  +--rw e-lmi?            control-mode
           |  |  +--rw lldp?             boolean
           |  |  +--rw ptp-peer-delay?   control-mode
           |  |  +--rw garp-mrp?         control-mode
           |  +--rw oam {oam}
           |     +--rw md-name         string
           |     +--rw md-level        uint16
           |     +--rw cfm-802.1-ag* [maid]
           |     |  +--rw maid                     string
           |     |  +--rw mep-id?                  uint32
           |     |  +--rw mep-level?               uint32
           |     |  +--rw mep-up-down?             enumeration
           |     |  +--rw remote-mep-id?           uint32
           |     |  +--rw cos-for-cfm-pdus?        uint32
           |     |  +--rw ccm-interval?            uint32
           |     |  +--rw ccm-holdtime?            uint32
           |     |  +--rw alarm-priority-defect?   identityref
           |     |  +--rw ccm-p-bits-pri?       ccm-priority-type
           |     +--rw y-1731* [maid]
           |        +--rw maid                           string
           |        +--rw mep-id?                        uint32
           |        +--rw type?                       identityref
           |        +--rw remote-mep-id?                 uint32
           |        +--rw message-period?                uint32
           |        +--rw measurement-interval?          uint32
           |        +--rw cos?                           uint32
           |        +--rw loss-measurement?              boolean
           |        +--rw synthethic-loss-measurement?   boolean
           |        +--rw delay-measurement
           |        |  +--rw enable-dm?   boolean
           |        |  +--rw two-way?     boolean
           |        +--rw frame-size?                    uint32
           |        +--rw session-type?               enumeration
           +--rw availability
           |  +--rw access-priority?   uint32



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           |  +--rw (redundancy-mode)?
           |     +--:(single-active)
           |     |  +--rw single-active?     empty
           |     +--:(all-active)
           |        +--rw all-active?        empty
           +--rw vpn-attachment
           |  +--rw (attachment-flavor)
           |     +--:(vpn-id)
           |     |  +--rw vpn-id?
           |     |  |    -> /l2vpn-svc/vpn-services/
           |     |  |            vpn-service/vpn-id
           |     |  +--rw site-role?              identityref
           |     +--:(vpn-policy-id)
           |        +--rw vpn-policy-id?
           |             -> ../../../../vpn-policies/
           |                     vpn-policy/vpn-policy-id
           +--rw service
           |  +--rw svc-bandwidth {input-bw}?
           |  |  +--rw bandwidth* [direction type]
           |  |     +--rw direction    identityref
           |  |     +--rw type         identityref
           |  |     +--rw cos-id?      uint8
           |  |     +--rw vpn-id?      svc-id
           |  |     +--rw cir          uint64
           |  |     +--rw cbs          uint64
           |  |     +--rw eir?         uint64
           |  |     +--rw ebs?         uint64
           |  |     +--rw pir?         uint64
           |  |     +--rw pbs?         uint64
           |  +--rw svc-mtu            uint16
           |  +--rw qos {qos}?
           |  |  +--rw classification-policy
           |  |  |  +--rw rule* [id]
           |  |  |     +--rw id                   string
           |  |  |     +--rw (match-type)?
           |  |  |     |  +--:(match-flow)
           |  |  |     |  |  +--rw match-flow
           |  |  |     |  |     +--rw dscp?           inet:dscp
           |  |  |     |  |     +--rw dot1q?          uint16
           |  |  |     |  |     +--rw pcp?            uint8
           |  |  |     |  |     +--rw src-mac?  yang:mac-address
           |  |  |     |  |     +--rw dst-mac?  yang:mac-address
           |  |  |     |  |     +--rw color-type?     identityref
           |  |  |     |  |     +--rw target-sites*
           |  |  |     |  |     |          svc-id {target-sites}?
           |  |  |     |  |     +--rw any?            empty
           |  |  |     |  |     +--rw vpn-id?         svc-id
           |  |  |     |  +--:(match-application)



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           |  |  |     |     +--rw match-application? identityref
           |  |  |     +--rw target-class-id?     string
           |  |  +--rw qos-profile
           |  |     +--rw (qos-profile)?
           |  |        +--:(standard)
           |  |        |  +--rw profile?
           |  |        |       -> /l2vpn-svc/vpn-profiles/
           |  |        |              valid-provider-identifiers/
           |  |        |              qos-profile-identifier
           |  |        +--:(custom)
           |  |           +--rw classes {qos-custom}?
           |  |              +--rw class* [class-id]
           |  |                 +--rw class-id        string
           |  |                 +--rw direction?      identityref
           |  |                 +--rw policing?       identityref
           |  |                 +--rw byte-offset?    uint16
           |  |                 +--rw frame-delay
           |  |                 |  +--rw (flavor)?
           |  |                 |     +--:(lowest)
           |  |                 |     |  +--rw use-lowest-latency?
           |  |                 |     |                     empty
           |  |                 |     +--:(boundary)
           |  |                 |        +--rw delay-bound? uint16
           |  |                 +--rw frame-jitter
           |  |                 |  +--rw (flavor)?
           |  |                 |     +--:(lowest)
           |  |                 |     |  +--rw use-lowest-jitter?
           |  |                 |     |                     empty
           |  |                 |     +--:(boundary)
           |  |                 |        +--rw delay-bound? uint32
           |  |                 +--rw frame-loss
           |  |                 |  +--rw rate?   decimal64
           |  |                 +--rw bandwidth
           |  |                    +--rw guaranteed-bw-percent
           |  |                    |                    decimal64
           |  |                    +--rw end-to-end?       empty
           |  +--rw carrierscarrier {carrierscarrier}?
           |     +--rw signaling-type?   identityref
           +--rw broadcast-unknown-unicast-multicast {bum}?
           |  +--rw multicast-site-type?            enumeration
           |  +--rw multicast-gp-address-mapping* [id]
           |  |  +--rw id                 uint16
           |  |  +--rw vlan-id            uint16
           |  |  +--rw mac-gp-address     yang:mac-address
           |  |  +--rw port-lag-number?   uint32
           |  +--rw bum-overall-rate?               uint32
           |  +--rw bum-rate-per-type* [type]
           |     +--rw type    identityref



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           |     +--rw rate?   uint32
           +--rw mac-loop-prevention {mac-loop-prevention}?
           |  +--rw protection-type?   identityref
           |  +--rw frequency?         uint32
           |  +--rw retry-timer?       uint32
           +--rw access-control-list
           |  +--rw mac* [mac-address]
           |     +--rw mac-address    yang:mac-address
           +--rw mac-addr-limit
           +--rw limit-number?    uint16
           +--rw time-interval?   uint32
           +--rw action?          identityref

                                 Figure 4

5.1.  Features and Augmentation

   The model defined in this document implements many features that
   allow implementations to be modular.  As an example, the layer 2
   protocols parameters (Section 5.3.2.2) proposed to the customer may
   also be enabled through features.  This model also defines some
   features for options that are more advanced, such as support for
   extranet VPNs (Section 5.2.4), site diversity (Section 5.3), and QoS
   (Section 5.10.2).

   In addition, as for any YANG model, this service model can be
   augmented to implement new behaviors or specific features.  For
   example, this model defines VXLAN [RFC7348] for Ethernet packet
   Encapsulation; if VXLAN Encapsulation does not fulfill all
   requirements for describing the service, new options can be added
   through augmentation.

5.2.  VPN Service Overview

   A vpn-service list item contains generic information about the VPN
   service.  The vpn-id of the vpn-service refers to an internal
   reference for this VPN service.  This identifier is purely internal
   to the organization responsible for the VPN service.

   A vpn-service is composed of some characteristics:

   Customer information:  Used to identify the customer.

   VPN Service Type (svc-type):  Used to indicate the VPN service Type.
      The identifier is an identity allowing any encoding for the local
      administration of the VPN service.  Note that other identity can
      be an extension of the base identity.




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   Cloud Access (cloud-access):  All sites in the L2VPN SHOULD be
      permitted to access to the cloud by default.  The cloud-access
      container provides parameters for authorization rules.  A cloud
      identifier is used to reference the target service.  This
      identifier is local to each administration.

   Service Topology (svc-topo):  Used to identify the type of VPN
      service topology that is required.

   Frame Delivery Service (frame-delivery):  Defines the frame delivery
      support required for the L2VPN, e.g., multicast delivery, unicast
      delivery, or broadcast delivery.

   Extranet VPN (extranet-vpns):  Indicates that a particular VPN needs
      access to resources located in another VPN.

5.2.1.  VPN Service Type

   The "vpn-svc-type" defines the service type for provider provisioned
   L2VPNs.  The current version of the model supports six flavors:

   o  Point-to-point Virtual Private Wire Services (VPWS) connecting two
      customer Sites;

   o  Point-to-point or point-to-multipoint Virtual Private Wire
      Services (VPWS) connecting a set of customer sites [RFC8214];

   o  Multipoint Virtual Private LAN services (VPLS) connecting a set of
      customer sites;

   o  Multipoint Virtual Private LAN services (VPLS) connecting one or
      more root sites and a set of leaf sites, but preventing inter-leaf
      sites communication.

   o  EVPN Service connecting a set of customer sites.

   o  Ethernet VPN VPWS between two customer sites or a set of customer
      sites specified in [RFC8214] and [RFC7432];

   Other L2VPN Service Types could be included by augmentation.  Note
   that an Ethernet Private Line (EPL) service or an Ethernet Virtual
   Private Line (EVPL) service is an E-Line service [MEF-6]or a point-
   to-point Ethernet Virtual Circuit (EVC) service, while an Ethernet
   Private LAN (EP-LAN) service or an Ethernet Virtual Private LAN (EVP-
   LAN) service is an E-LAN service [MEF-6] or a multipoint-to-
   multipoint EVC service.





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5.2.2.  VPN Service Topology

   The type of VPN service topology can be used for configuration if
   needed.  The module currently supports: any-to-any; hub-and-spoke
   (where hubs can exchange traffic); and hub-and-spoke-disjoint (where
   hubs cannot exchange traffic).  New topologies could be added by
   augmentation.  By default, the any-to-any VPN service topology is
   used.

5.2.2.1.  Route Target Allocation

   A Layer 2 PE-based VPN (such as a VPLS-based VPN, or an EVPN that
   uses BGP as its signaling protocol) can be built using route targets
   (RTs) as described in [RFC4364] an [RFC7432].  The management system
   is expected to automatically allocate a set of RTs upon receiving a
   VPN service creation request.  How the management system allocates
   RTs is out of scope for this document, but multiple ways could be
   envisaged, as described in the Section 6.2.1.1 of [RFC8299].

5.2.2.2.  Any-to-Any

        +------------------------------------------------------------+
        |  VPN1_Site1 ------ PE1               PE2 ------ VPN1_Site2 |
        |                                                            |
        |  VPN1_Site3 ------ PE3               PE4 ------ VPN1_Site4 |
        +------------------------------------------------------------+

                      Any-to-Any VPN Service Topology

   In the any-to-any VPN service topology, all VPN sites can communicate
   with each other without any restrictions.  The management system that
   receives an any-to-any L2VPN service request through this model is
   expected to assign and then configure the MAC-VRF and RTs on the
   appropriate PEs.  In the any-to-any case, a single RT is generally
   required, and every MAC-VRF imports and exports this RT.

5.2.2.3.  Hub-and-Spoke

        +-------------------------------------------------------------+
        |   Hub_Site1 ------ PE1               PE2 ------ Spoke_Site1 |
        |                          +----------------------------------+
        |                          |
        |                          +----------------------------------+
        |   Hub_Site2 ------ PE3               PE4 ------ Spoke_Site2 |
        +-------------------------------------------------------------+

                    Hub-and-Spoke VPN Service Topology




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   In the Hub-and-Spoke VPN service topology, all Spoke sites can
   communicate only with Hub sites, but not with each other.  And Hubs
   can also communicate with each other.  The management system that
   receives a Hub-and-Spoke L2VPN service request through this model is
   expected to assign and then configure the MAC-VRF and RTs on the
   appropriate PEs.  In the Hub-and-Spoke case, two RTs are generally
   required (one RT for Hub routes, and one RT for Spoke routes).  A Hub
   MAC-VRF that connects Hub sites will export Hub routes with the Hub
   RT and will import Spoke routes through the Spoke RT.  It will also
   import the Hub RT to allow Hub-to-Hub communication.  A Spoke MAC-VRF
   that connects Spoke sites will export Spoke routes with the Spoke RT
   and will import Hub routes through the Hub RT.

5.2.2.4.  Hub-and-Spoke-Disjoint

        +-------------------------------------------------------------+
        |   Hub_Site1 ------ PE1               PE2 ------ Spoke_Site1 |
        +--------------------------+  +-------------------------------+
                                   |  |
        +--------------------------+  +-------------------------------+
        |   Hub_Site2 ------ PE3               PE4 ------ Spoke_Site2 |
        +-------------------------------------------------------------+

                Hub-and-Spoke-Disjoint VPN Service Topology

   In the Hub-and-Spoke-Disjoint VPN service topology, all Spoke sites
   can communicate only with Hub sites, but not with each other.  And
   Hubs cannot communicate with each other.  The management system that
   receives a Hub-and-Spoke-Disjoint L2VPN service request through this
   model is expected to assign and then configure the VRF and RTs on the
   appropriate PEs.  In the Hub-and-Spoke-Disjoint case, at least two
   RTs are required for Hub and Spoke respectively(one RT for Hub routes
   and one RT for Spoke routes).  A Hub VRF that connects Hub sites will
   export Hub routes with the Hub RT and will import Spoke routes
   through the Spoke RT.  A Spoke VRF that connects Spoke sites will
   export Spoke routes with the Spoke RT and will import Hub routes
   through the Hub RT.

   The management system MUST take into account constraints on Hub-and-
   Spoke connections, as in the previous case.

   Hub-and-Spoke-Disjoint can also be seen as multiple Hub-and-Spoke
   VPNs (one per Hub) that share a common set of Spoke sites.








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5.2.3.  Cloud Access

   This model provides cloud access configuration through the cloud-
   access container.  The usage of cloud-access is targeted for public
   cloud and for Internet access.  The cloud-access container provides
   parameters for authorization rules.  Note that this model considers
   that public cloud and public Internet access share some commonality,
   therefore it does not distinguish Internet access from cloud access.
   Anyway, a different label for Internet access could be added by
   augmentation.

   Private cloud access may be addressed through the site container as
   described in Section 5.3 with use consistent with sites of type NNI
   (Network to Network Interface).

   A cloud identifier is used to reference the target service.  This
   identifier is local to each administration.

   By default, all sites in the L2VPN SHOULD be permitted to access the
   cloud or internet.  If restrictions are required, a user MAY
   configure some limitations for some sites or nodes by using policies,
   i.e. the "permit-site" or "deny-site" leaf-list.  The permit-site
   leaf-list defines the list of sites authorized for cloud access.  The
   deny-site leaf-list defines the list of sites denied for cloud
   access.  The model supports both "deny-any-except" and "permit-any-
   except" authorization.

   How the restrictions will be configured on network elements is out of
   scope for this document.

                        L2VPN
              ++++++++++++++++++++++++++++++++     ++++++++++++
              +            Site 3            + --- +  Cloud 1 +
              + Site 1                       +     ++++++++++++
              +                              +
              + Site 2                       + --- ++++++++++++
              +                              +     + Internet +
              +            Site 4            +     ++++++++++++
              ++++++++++++++++++++++++++++++++
                           |
                      +++++++++++
                      + Cloud 2 +
                      +++++++++++

   In the example above, we configure the global VPN to access the
   Internet by creating a cloud-access container pointing to the cloud
   identifier for the Internet service.  No authorized sites will be




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   configured, as all sites are required to be able to access the
   Internet.

    <?xml version="1.0"?>
       <l2vpn-svc xmlns="urn:ietf:params:xml:ns:yang:ietf-l2vpn-svc">
       <vpn-services>
       <vpn-service>
       <vpn-id>123456487</vpn-id>
      <cloud-accesses>
       <cloud-access>
          <cloud-identifier>INTERNET</cloud-identifier>
       </cloud-access>
      </cloud-accesses>
      <ce-vlan-preservation>true</ce-vlan-preservation>
      <ce-vlan-cos-preservation>true</ce-vlan-cos-preservation>
      </vpn-service>
      </vpn-services>
    </l2vpn-svc>

   If Site 1 and Site 2 require access to Cloud 1, a new cloud-access
   container pointing to the cloud identifier of Cloud 1 will be
   created.  The permit-site leaf-list will be filled with a reference
   to Site 1 and Site 2.

    <?xml version="1.0"?>
       <l2vpn-svc xmlns="urn:ietf:params:xml:ns:yang:ietf-l2vpn-svc">
        <vpn-services>
         <vpn-service>
         <vpn-id>123456487</vpn-id>
         <cloud-accesses>
          <cloud-access>
            <cloud-identifier>Cloud1</cloud-identifier>
            <permit-site>site1</permit-site>
            <permit-site>site2</permit-site>
          </cloud-access>
         </cloud-accesses>
        <ce-vlan-preservation>true</ce-vlan-preservation>
        <ce-vlan-cos-preservation>true</ce-vlan-cos-preservation>
       </vpn-service>
       </vpn-services>
    </l2vpn-svc>

   If all sites except Site 1 require access to Cloud 2, a new cloud-
   access container pointing to the cloud identifier of Cloud 2 will be
   created.  The deny-site leaf-list will be filled with a reference to
   Site 1.





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    <?xml version="1.0"?>
      <l2vpn-svc xmlns="urn:ietf:params:xml:ns:yang:ietf-l2vpn-svc">
        <vpn-services>
         <vpn-service>
           <vpn-id>123456487</vpn-id>
            <cloud-accesses>
             <cloud-access>
              <cloud-identifier>Cloud2</cloud-identifier>
              <deny-site>site1</deny-site>
            </cloud-access>
           </cloud-accesses>
          <ce-vlan-preservation>true</ce-vlan-preservation>
          <ce-vlan-cos-preservation>true</ce-vlan-cos-preservation>
        </vpn-service>
      </vpn-services>
    </l2vpn-svc>

5.2.4.  Extranet VPNs

   There are some cases where a particular VPN needs access to resources
   (servers, hosts, etc.) that are external.  Those resources may be
   located in another VPN.

                 +-----------+           +-----------+
                /             \         /             \
     Site A -- |    VPN A      |  ---  |    VPN B      | --- Site B
                \             /         \             /      (Shared
                 +-----------+           +-----------+        resources)

   In the figure above, VPN B has some resources on Site B that need to
   be made available to some customers/partners.  Specifically, VPN A
   must be able to access those VPN B resources.

   Such a VPN connection scenario can be achieved via a VPN policy as
   defined in Section 5.5.2.2.  But there are some simple cases where a
   particular VPN (VPN A) needs access to all resources in another VPN
   (VPN B).  The model provides an easy way to set up this connection
   using the "extranet-vpns" container.

   The extranet-vpns container defines a list of VPNs a particular VPN
   wants to access.  The extranet-vpns container is used on customer
   VPNs accessing extranet resources in another VPN.  In the figure
   above, in order to provide VPN A with access to VPN B, the extranet-
   vpns container needs to be configured under VPN A with an entry
   corresponding to VPN B.  There is no service configuration
   requirement on VPN B.





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   Readers should note that even if there is no configuration
   requirement on VPN B, if VPN A lists VPN B as an extranet, all sites
   in VPN B will gain access to all sites in VPN A.

   The "site-role" leaf defines the role of the local VPN sites in the
   target extranet VPN service topology.  Site roles are defined in
   Section 5.4.

   In the example below, VPN A accesses VPN B resources through an
   extranet connection.  A Spoke role is required for VPN A sites, as
   sites from VPN A must not be able to communicate with each other
   through the extranet VPN connection.

     <?xml version="1.0"?>
       <l2vpn-svc xmlns="urn:ietf:params:xml:ns:yang:ietf-l2vpn-svc">
        <vpn-services>
          <vpn-service>
            <vpn-id>VPNB</vpn-id>
              <svc-topo>hub-spoke</svc-topo>
             <ce-vlan-preservation>true</ce-vlan-preservation>
             <ce-vlan-cos-preservation>true</ce-vlan-cos-preservation>
          </vpn-service>
          <vpn-service>
             <vpn-id>VPNA</vpn-id>
               <svc-topo>any-to-any</svc-topo>
                  <extranet-vpns>
                    <extranet-vpn>
                     <vpn-id>VPNB</vpn-id>
                     <local-sites-role>spoke-role</local-sites-role>
                   </extranet-vpn>
                 </extranet-vpns>
             <ce-vlan-preservation>true</ce-vlan-preservation>
             <ce-vlan-cos-preservation>true</ce-vlan-cos-preservation>
         </vpn-service>
       </vpn-services>
      </l2vpn-svc>

   This model does not define how the extranet configuration will be
   achieved within the network.

   Any VPN interconnection scenario that is more complex (e.g., only
   certain parts of sites on VPN A accessing only certain parts of sites
   on VPN B) needs to be achieved using a VPN attachment as defined in
   Section 5.5.2, and especially a VPN policy as defined in
   Section 5.5.2.2.






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5.2.5.  Frame Delivery Service

   If BUM (Broadcast/Unknown/Multicast) Frame Delivery Service is
   supported for an L2VPN, some global frame delivery parameters are
   required as input for the service request.  When a CE sends packets
   that are Broadcast, Multicast, or Unknown-destination-unicast,
   replication occurs at the ingress PE, three frame types need to be
   supported.

   Users of this model will need to provide the flavors of trees that
   will be used by customers within the L2VPN (customer-tree-flavors).
   The model defined in this document supports bidirectional, shared,
   and source-based trees (and can be augmented to contain other tree
   types).  Multiple flavors of trees can be supported simultaneously.

                                Operator network
                                ______________
                               /              \
                              |                |
                              |                |
       Recv -- Site2 ------- PE2               |
                              |               PE1 --- Site1 --- Source1
                              |                |        \
                              |                |         -- Source2
                              |                |
                              |                |
       Recv -- Site3 ------- PE3               |
                              |                |
                              |                |
       Recv -- Site4 ------- PE4               |
                            / |                |
       Recv -- Site5 -------  |                |
                              |                |
                              |                |
                               \_______________/

   Multicast Group to port mappings can be created using the "rp-group-
   mappings" leaf.  Two group to port mapping methods are supported:

   o  Static configuration of multicast Ethernet addresses and ports/
      interfaces.

   o  Multicast control protocol based on Layer-2 technology that
      signals mappings of multicast addresses to ports/interfaces, such
      as Generic Attribute Registration Protocol / GARP Multicast
      Registration Protocol (GARP/GMRP) [IEEE-802-1D].





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5.3.  Site Overview

   A site represents a connection of a customer office to one or more
   VPN services.  Each site is associated with one or more location.

                                                       +-------------+
                                                      /               \
                                               +-----|      VPN1       |
        +------------------+                   |      \               /
        |                  |                   |       +-------------+
        |  New York Office |------ (site) -----+
        |                  |                   |       +-------------+
        +------------------+                   |      /               \
                                               +-----|      VPN2       |
                                                      \               /
                                                       +-------------+

   The "site" container is used for the provider to store information of
   detailed implementation arrangements made with either the customer or
   with peer operators at each inter-connect location.

   We restrict the L2SM to exterior interfaces (i.e.,UNI and NNI) only,
   so all internal interfaces and the underlying topology are outside
   the scope of L2SM.

   Typically, the following characteristics of a site interface handoff
   need to be documented as part of the service design:

   Unique identifier (site-id):  An arbitrary string to uniquely
      identify the site within the overall network infrastructure.  The
      format of site-id is determined by the local administration of the
      VPN service.

   Device (device):  The customer can request one or more customer
      premise equipments from the service provider for a particular
      site.

   Management (management):  Defines the model of management for the
      site, for example: type, management-transport, address.  This
      decides the boundary between service provider and customer: who
      has ownership of CE device.

   Location (location):  The site location information to allow easy
      retrieval of data about which are the nearest available resources.

   Site diversity (site-diversity):  Presents some parameters to support
      site diversity.




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   Site Network Accesses (site-network-accesses):  Defines the list of
      ports to the site and their properties: especially bearer,
      connection, and service parameters.

   A site-network-access represents an Ethernet logical connection to a
   site.  A site may have multiple site-network-accesses.

        +------------------+             Site
        |                  |-----------------------------------
        |                  |****** (site-network-access#1) ******
        |  New York Office |
        |                  |****** (site-network-access#2) ******
        |                  |-----------------------------------
        +------------------+

   Multiple site-network-accesses are used, for instance, in the case of
   multihoming.  Some other meshing cases may also include multiple
   site-network-accesses.

   The site configuration is viewed as a global entity; we assume that
   it is mostly the management system's role to split the parameters
   between the different elements within the network.  For example, in
   the case of the site-network-access configuration, the management
   system needs to split the parameters between the PE configuration and
   the CE configuration.

   The site may support single-homed acess or multihoming.  In the case
   of multihoming, the site can support multiple site-network-accesses,
   under each site-network-access, vpn-attachment is defined and it will
   describe which site-network-access associated with which site will
   connect to which VPN.

5.3.1.  Devices and Locations

   The information in the "location" sub-container under a "site" and in
   the "device" container allows easy retrieval of data about which are
   the nearest available facilities and can be used for access topology
   planning.  It may also be used by other network orchestration
   components to choose the targeted upstream PE and downstream CE.
   Location is expressed in terms of postal information.  More detailed
   or other location information can be added by augmentation.

   A site may be composed of multiple locations.  All the locations will
   need to be configured as part of the "locations" container and list.
   A typical example of a multi-location site is a headquarters office
   in a city composed of multiple buildings.  Those buildings may be
   located in different parts of the city and may be linked by intra-
   city fibers (a customer metropolitan area network).  This model does



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   not represent the connectivity between the multiple locations of a
   site, because that connectivity is controlled by the customer.  In
   such a case, when connecting to a VPN service, the customer may ask
   for multihoming based on its distributed locations.

            New York Site
        +------------------+             Site
        | +--------------+ |-----------------------------------
        | | Manhattan    | |****** (site-network-access#1) ******
        | +--------------+ |
        | +--------------+ |
        | | Brooklyn     | |****** (site-network-access#2) ******
        | +--------------+ |-----------------------------------
        +------------------+

   A customer may also request the use of some premises equipment
   entities (CEs) from the SP via the "devices" container.  Requesting a
   CE implies a provider-managed or co-managed model.  A particular
   device must be ordered to a particular already-configured location.
   This would help the SP send the device to the appropriate postal
   address.  In a multi-location site, a customer may, for example,
   request a CE for each location on the site where multihoming must be
   implemented.  In the figure above, one device may be requested for
   the Manhattan location and one other for the Brooklyn location.

   By using devices and locations, the user can influence the
   multihoming scenario he wants to implement: single CE, dual CE, etc.

5.3.2.  Site Network Accesses

   The L2SM includes a set of essential physical interface properties
   and Ethernet layer characteristics in the "site-network-accesses"
   container.  Some of these are critical implementation arrangements
   that require consent from both customer and provider.

   As mentioned earlier, a site may be multihomed.  Each logical network
   access for a site is defined in the "site-network-accesses"
   container.  The site-network-access parameter defines how the site is
   connected on the network and is split into three main classes of
   parameters:

   o  bearer: defines requirements of the attachment (below Layer 2).

   o  connection: defines Layer 2 protocol parameters of the attachment.

   o  availability: defines the site's availability policy.  The
      availability parameters are defined in Section 5.8.




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   The site-network-access has a specific type (site-network-access-
   type).  This document defines two types:

   o  point-to-point: describes a point-to-point connection between the
      SP and the customer.

   o  multipoint: describes a multipoint connection between the SP and
      the customer.

   This site-network-access type may have an impact on the parameters
   offered to the customer, e.g., an SP might not offer MAC Loop
   Protection for multipoint accesses.  It is up to the provider to
   decide what parameters are supported for point-to-point and/or
   multipoint accesses.  Multipoint accesses are out of scope for this
   document and some containers defined in the model may require
   extensions in order to work properly for multipoint accesses.

5.3.2.1.  Bearer

   The "bearer" container defines the requirements for the site
   attachment to the provider network that are below Layer 2.

   The bearer parameters will help to determine the access media to be
   used.

5.3.2.2.  Connection

   The "connection" container defines the layer 2 protocol parameters of
   the attachment (e.g.,vlan-id or circuit-id) and provides connectivity
   between customer Ethernet switches.  Depending on the management
   mode, it refers to PE-CE-LAN segment addressing or to CE-to-customer-
   LAN segment addressing.  In any case, it describes the responsibility
   boundary between the provider and the customer.  For a customer-
   managed site, it refers to the PE-CE-LAN Segment connection.  For a
   provider-managed site, it refers to the CE-to-LAN Segment connection.

   "encapsulation-type" allows the user to select between Ethernet
   encapsulation (port-based) or Ethernet VLAN encapsulation (VLAN-
   based).  All of the allowed Ethernet interface types of service frame
   can be listed under "ether-inf-type", e.g., untagged interface,
   tagged interface, LAG interface.

   Corresponding to "ether-inf-type", the connection container also
   presents three sets of link attributes: untagged interface, tagged
   interface, or optional LAG interface attributes.  These parameters
   are essential for the connection to establish properly between the
   customer and provider edge devices.  The connection container also




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   defines an L2CP attribute to allow control plane protocol interaction
   between the CE devices and PE device.

5.3.2.2.1.  Untagged Interface

   For each untagged interface (untagged-interface), there are basic
   configuration parameters like interface index and speed, interface
   MTU, auto-negotiation and flow-control settings, etc.  In addition
   and based on mutual agreement, the customer and provider may decide
   to enable advanced features, such as LLDP, IEEE 802.3ah, MAC loop
   detection/prevention at a UNI.  If Loop avoidance is required, the
   attribute "uni-loop-prevention" must be set to TRUE.

5.3.2.2.2.  Tagged Interface

   If the tagged service is enabled on a logical unit on the connection
   at the interface, "encapsulation-type" should be specified as the
   Ethernet VLAN ecapsulation (if VLAN-based) or VXLAN encapsulation,
   and "eth-inf-type" should be set to indicate a tagged interface.

   In addition, "tagged-interface-type" should be specified under
   "tagged-interface" container to determines how tagging needs to be
   done.  The current model defines five ways to perform VLAN tagging:

   o  priority-tagged: Service providers encapsulate and tag packets
      between CE and PE with the frame priority level.

   o  dot1q-vlan-tagged: Service providers encapsulate packets between
      CE and PE with one or a set of customer VLAN IDs (C-VLANs)

   o  qinq: service providers encapsulate packets that enter the
      service-provider network with multiple customer VLAN IDs (C-VLANs)
      and a single VLAN tag with a single service provider VLAN
      (S-VLAN).

   o  qinany: service providers encapsulate packets that enter the
      service-provider network with unknown C-VLAN and a single VLAN tag
      with a single service provider VLAN (S-VLAN).

   o  vxlan: service providers encapsulate packets that enter the
      service-provider network with VNI and peer list.

   The overall S-tag for the Ethernet circuit and C-tag-to-SVC mapping,
   if applicable, has been placed in the service container.  For the
   qinq an qinany options, the S-tag under "qinq" and "qinany" should
   match the S-tag in the service container in most cases, however, vlan
   translation is required for the S-tag in certain deployment at the
   external facing interface or upstream PEs to "normalize" the outer



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   VLAN tag to the service S-tag into the network and translate back to
   the site's S-tag in the opposite direction.  One example of this is
   with a Layer 2 aggregation switch along the path: the S-tag for the
   SVC has been previously assigned to another service thus can not be
   used by this attachment circuit.

5.3.2.2.3.  LAG Interface

   Sometimes, the customer may require multiple physical links bundled
   together to form a single, logical, point-to-point LAG connection to
   the service provider.  Typically, LACP (Link Aggregation Control
   Protocol) is used to dynamically manage adding or deleting member
   links of the aggregate group.  In general, a LAG allows for increased
   service bandwidth beyond the speed of a single physical link while
   providing graceful degradation as failure occurs, thus increased
   availability.

   In the L2SM, there is a set of attributes under "LAG-interface"
   related to link aggregation functionality.  The customer and provider
   first need to decide on whether LACP PDUs will be exchanged between
   the edge devices by specifying the "LACP-state" to "On" or "Off".  If
   LACP is to be enabled, then both parties need to further specify
   whether it will be running in active or passive mode, plus the time
   interval and priority level of the LACP PDU.  The customer and
   provider can also determine the minimum aggregate bandwidth for a LAG
   to be considered as a valid path by specifying the optional "mini-
   link" attribute.  To enable fast detection of faulty links, micro-BFD
   [RFC7130]runs independent UDP sessions to monitor the status of each
   member link.  Customer and provider should agree the BFD hello
   interval and hold time.

   Each member link will be listed under the LAG interface with basic
   physical link properties.  Certain attributes like flow-control,
   encapsulation type, allowed ingress Ethertype and LLDP settings are
   at the LAG level.

5.3.2.2.4.  CVLAN ID To SVC MAP

   When more than one service is multiplexed onto the same interface,
   ingress service frames are conditionally transmitted through one of
   the L2VPN services based upon pre-arranged customer VLAN-to-SVC
   mapping.  Multiple customer VLANs can be bundled across the same SVC.
   The bundling type will determine how a group of CVLANs is bundled
   into one VPN service (i.e., VLAN-Bundling).

   "cvlan-id-to-svc-map", when applicable, contains the list of customer
   VLANs that are mapped to the same service.  In most cases, this will
   be the VLAN access-list for the inner 802.1q tag (the C-tag).



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   A VPN Service can be set to preserve the CE-VLAN ID and CE-VLAN CoS
   from source site to destination site.  This is required when the
   customer wants to use the VLAN header information between its two
   sites.  CE-VLAN ID Preservation and CE-VLAN CoS Preservation are
   applied on each site-network-access within sites.  Preservation means
   that the value of CE-VLAN ID and/or CE-VLAN CoS at source site must
   be equal to the value at a destination site belonging to the same
   L2VPN Service.

   If All-to-One bundling is Enabled (i.e., bundling type is set to all-
   to-one bundling), then preservation applies to all Ingress service
   frames.  If All-to-One bundling is Disabled, then preservation
   applies to tagged Ingress service frames having the CE-VLAN ID.

5.3.2.2.5.  L2CP Control Support

   Customer and Service provider should pre-arrange whether to allow
   control plane protocol interaction between the CE devices and PE
   device.  To provide seamless operation with multicast data transport,
   the transparent operation of Ethernet control protocols (e.g.,
   Spanning Tree Protocol [IEEE-802-1D]) can be employed by customers.

   To support efficient dynamic transport, Ethernet multicast control
   frames (e.g., GARP/GMRP [IEEE-802-1D]) can be used between CE and PE.
   However, solutions MUST NOT assume all CEs are always running such
   protocols (typically in the case where a CE is a router and is not
   aware of Layer-2 details).

   The destination MAC addresses of these L2CP PDUs fall within two
   reserved blocks specified by the IEEE 802.1 Working Group.  Packet
   with destination MAC in these multicast ranges have special
   forwarding rules.

   o  Bridge Block of Protocols: 01-80-C2-00-00-00 through
      01-80-C2-00-00-0F

   o  MRP Block of Protocols: 01-80-C2-00-00-20 through
      01-80-C2-00-00-2F

   Layer 2 protocol tunneling allows service providers to pass
   subscriber Layer 2 control PDUs across the network without being
   interpreted and processed by intermediate network devices.  These
   L2CP PDUs are transparently encapsulated across the MPLS-enabled core
   network in Q-in-Q fashion.

   The "L2CP-control" container contains the list of commonly used L2CP
   protocols and parameters.  The service provider can specify DISCARD,
   PEER, or TUNNEL mode actions for each individual protocol.



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5.3.2.2.6.  Ethernet Service OAM

   The advent of Ethernet as a wide-area network technology brings
   additional requirements of end-to-end service monitoring and fault
   management in the SP network, particularly in the area of service
   availability and Mean Time To Repair (MTTR).  Ethernet Service OAM in
   the L2SM model refers to the combined protocol suites of IEEE 802.1ag
   ([IEEE-802-1ag]) and ITU-T Y.1731 ([ITU-T-Y-1731]).

   Generally speaking, Ethernet Service OAM enables service providers to
   perform service continuity check, fault-isolation, and packet delay/
   jitter measurement at per-customer and per-site network access
   granularity.  The information collected from Ethernet Service OAM
   data sets is complementary to other higher layer IP/MPLS OSS tools to
   ensure the required service level agreements (SLAs) can be meet.

   The 802.1ag Connectivity Fault Management (CFM) functional model is
   structured with hierarchical maintenance domains (MDs), each assigned
   with a unique maintenance level.  Higher level MDs can be nested over
   lower level MDs.  However, the MDs cannot intersect.  The scope of
   each MD can be solely within a customer network, solely within the SP
   network, interact between the customer-to-provider or provider-to-
   provider edge equipment, or tunnel over another SP network.

   Depending on the use case scenario, one or more maintenance end
   points (MEPs) can be placed on the external facing interface, sending
   CFM PDUs towards the core network (Up MEP) or downstream link (Down
   MEP).

   The "cfm-802.1-ag" sub-container under "site-network-access" presents
   the CFM maintenance association (MA): i.e., Down MEP for the UNI MA.
   For each MA, the user can define the maintenance domain ID (MAID),
   MEP level, MEP direction, remote MEP ID, CoS level of the CFM PDUs,
   Continuity Check Message (CCM) interval and hold time, alarm priority
   defect, CCM priority-type, etc.

   ITU-T Y.1731 Performance Monitoring (PM) provides essential network
   telemetry information that includes the measurement of Ethernet
   service frame delay, frame delay variation, frame loss, and frame
   throughput.  The delay/jitter measurement can be either one-way or
   two-way.  Typically, a Y.1731 PM probe sends a small amount of
   synthetic frames along with service frames to measure the SLA
   parameters.

   The "y-1731" sub-container under "site-network-access" contains a set
   of parameters to define the PM probe information, including MAID,
   local and remote MEP-ID, PM PDU type, message period and measurement
   interval, CoS level of the PM PDUs, loss measurement by synthetic or



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   service frame options, one-way or two-way delay measurement, PM frame
   size, and session type.

5.4.  Site Role

   A VPN has a particular service topology, as described in
   Section 5.2.2.  As a consequence, each site belonging to a VPN is
   assigned a particular role in this topology.  The site-role leaf
   defines the role of the site in a particular VPN topology.

   In the any-to-any VPN service topology, all sites MUST have the same
   role, which will be "any-to-any-role".

   In the Hub-and-Spoke VPN service topology or the Hub-and-Spoke-
   Disjoint VPN service topology, sites MUST have a Hub role or a Spoke
   role.

5.5.  Site Belonging to Multiple VPNs

5.5.1.  Site VPN Flavor

   A site may be part of one or more VPNs.  The "site-vpn-flavor"
   defines the way the VPN multiplexing is done.  There are four
   possible types of external facing connections associated with an
   Ethernet VPN service and a site.  Therefore the model supports four
   flavors:

   o  site-vpn-flavor-single: The site belongs to only one VPN.

   o  site-vpn-flavor-multi: The site belongs to multiple VPNs, and all
      the logical accesses of the sites belong to the same set of VPNs.

   o  site-vpn-flavor-nni: The site represents an NNI where two
      administrative domains belonging to the same or different
      providers inter-connect.

   o  site-vpn-flavor-e2e: The site represents an end-to-end multi-
      segment connection.

5.5.1.1.  Single VPN Attachment: site-vpn-flavor-single

   The figure below describes a single VPN attachment.  The site
   connects to only one VPN.








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                                                         +--------+
      +------------------+             Site             /          \
      |                  |-----------------------------|            |
      |                  |***(site-network-access#1)***|    VPN1    |
      |  New York Office |                             |            |
      |                  |***(site-network-access#2)***|            |
      |                  |-----------------------------|            |
      +------------------+                              \          /
                                                         +--------+

5.5.1.2.  MultiVPN Attachment: site-vpn-flavor-multi

   The figure below describes a site connected to multiple VPNs.

                                                           +---------+
                                                      +---/----+      \
   +------------------+             Site             /   |      \      |
   |                  |--------------------------------- |       |VPN B|
   |                  |***(site-network-access#1)******* |       |     |
   |  New York Office |                             |    |       |     |
   |                  |***(site-network-access#2)*******  \      |    /
   |                  |-----------------------------| VPN A+-----|---+
   +------------------+                              \          /
                                                      +--------+

   In the example above, the New York office is multihomed.  Both
   logical accesses are using the same VPN attachment rules, and both
   are connected to VPN A and to VPN B.

   Reaching VPN A or VPN B from the New York office will be done via MAC
   destination based forwarding.  Having the same destination reachable
   from the two VPNs may cause routing problems.  The customer
   administration's role in this case would be to ensure the appropriate
   mapping of its MAC addresses in each VPN.  See Section 5.5.2 and
   Section 5.10.2 for more details.  See also Section 5.10.3 for BUM
   support.

5.5.1.3.  NNI: site-vpn-flavor-nni

   A Network-to-Network Interface (NNI) scenario may be modeled using
   the sites container.  It is helpful for the SP to indicate that the
   requested VPN connection is not a regular site but rather is an NNI,
   as specific default device configuration parameters may be applied in
   the case of NNIs (e.g., ACLs, routing policies).







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              SP A                                         SP B
       -------------------                         -------------------
      /                   \                       /                   \
     |                     |                     |                     |
     |                 ++++++++ Inter-AS link ++++++++                 |
     |                 +      +_______________+      +                 |
     |                 + (MAC-VRF1)-(VPN1)-(MAC-VRF1)+                 |
     |                 +      +               +      +                 |
     |                 + ASBR +               + ASBR +                 |
     |                 +      +               +      +                 |
     |                 + (MAC-VRF2)-(VPN2)-(MAC-VRF2)+                 |
     |                 +      +_______________+      +                 |
     |                 ++++++++               ++++++++                 |
     |                     |                     |                     |
     |                     |                     |                     |
     |                     |                     |                     |
     |                 ++++++++ Inter-AS link ++++++++                 |
     |                 +      +_______________+      +                 |
     |                 + (MAC-VRF1)-(VPN1)-(MAC-VRF1)+                 |
     |                 +      +               +      +                 |
     |                 + ASBR +               + ASBR +                 |
     |                 +      +               +      +                 |
     |                 + (MAC-VRF2)-(VPN2)-(MAC-VRF2)+                 |
     |                 +      +_______________+      +                 |
     |                 ++++++++               ++++++++                 |
     |                     |                     |                     |
     |                     |                     |                     |
      \                   /                       \                   /
       -------------------                         -------------------

   The figure above describes an option A NNI scenario that can be
   modeled using the sites container.  In order to connect its customer
   VPNs (VPN1 and VPN2) in SP B, SP A may request the creation of some
   site-network-accesses to SP B.  The site-vpn-flavor-nni will be used
   to inform SP B that this is an NNI and not a regular customer site.

5.5.1.4.  E2E: site-vpn-flavor-e2e

   A end to end multi-segment VPN connection to be constructed out of
   several connectivity segments may be modeled.  It is helpful for the
   SP to indicate the requested VPN connection is not a regular site but
   rather is an end-to-end VPN connection, as specific default device
   configuration parameters may be applied in case of site-vpn-flavor-
   e2e (e.g., QoS configuration).  In order to establish a connection
   between Site 1 in SP A and Site 2 in SP B spanning across multiple
   domains, SP A may request the creation of end-to-end connectivity to
   SP B.  The site-vpn-flavor-e2e will be used to indicate that this is
   an end-to-end connectivity setup and not a regular customer site.



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5.5.2.  Attaching a Site to a VPN

   Due to the multiple site-vpn flavors, the attachment of a site to an
   L2VPN is done at the site-network-access (logical access) level
   through the "vpn-attachment" container.  The vpn-attachment container
   is mandatory.  The model provides two ways to attach a site to a VPN:

   o  By referencing the target VPN directly.

   o  By referencing a VPN policy for attachments that are more complex.

   A choice is implemented to allow the user to choose the flavor that
   provides the best fit.

5.5.2.1.  Referencing a VPN

   Referencing a vpn-id provides an easy way to attach a particular
   logical access to a VPN.  This is the best way in the case of a
   single VPN attachment.  When referencing a vpn-id, the site-role
   setting must be added to express the role of the site in the target
   VPN service topology.

    <?xml version="1.0"?>
    <l2vpn-svc xmlns="urn:ietf:params:xml:ns:yang:ietf-l2vpn-svc">
     <vpn-services>
        <vpn-service>
          <vpn-id>VPNA</vpn-id>
          <ce-vlan-preservation>true</ce-vlan-preservation>
          <ce-vlan-cos-preservation>true</ce-vlan-cos-preservation>
        </vpn-service>
        <vpn-service>
          <vpn-id>VPNB</vpn-id>
          <ce-vlan-preservation>true</ce-vlan-preservation>
          <ce-vlan-cos-preservation>true</ce-vlan-cos-preservation>
        </vpn-service>
     </vpn-services>
     <sites>
       <site>
        <site-id>SITE1</site-id>
       <locations>
        <location>
         <location-id>L1</location-id>
        </location>
       </locations>
       <management>
        <type>customer-managed</type>
          </management>
           <site-network-accesses>



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            <site-network-access>
             <network-access-id>LA1</network-access-id>
                <service>
                  <svc-bandwidth>
                     <bandwidth>
                       <direction>input-bw</direction>
                        <type>bw-per-cos</type>
                         <cir>450000000</cir>
                         <cbs>20000000</cbs>
                         <eir>1000000000</eir>
                         <ebs>200000000</ebs>
                      </bandwidth>
                    </svc-bandwidth>
                     <carrierscarrier>
                       <signaling-type>bgp</signaling-type>
                     </carrierscarrier>
                     <svc-mtu>1514<svc-mtu>
                   </service>
            <vpn-attachment>
             <vpn-id>VPNA</vpn-id>
             <site-role>spoke-role</site-role>
            </vpn-attachment>
           </site-network-access>
           <site-network-access>
            <network-access-id>LA2</network-access-id>
                <service>
                  <svc-bandwidth>
                     <bandwidth>
                       <direction>input-bw</direction>
                        <type>bw-per-cos</type>
                         <cir>450000000</cir>
                         <cbs>20000000</cbs>
                         <eir>1000000000</eir>
                         <ebs>200000000</ebs>
                     </bandwidth>
                    </svc-bandwidth>
                     <carrierscarrier>
                       <signaling-type>bgp</signaling-type>
                     </carrierscarrier>
                     <svc-mtu>1514<svc-mtu>
                   </service>
            <vpn-attachment>
             <vpn-id>VPNB</vpn-id>
             <site-role>spoke-role</site-role>
            </vpn-attachment>
           </site-network-access>
          </site-network-accesses>
      </site>



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     </sites>
    </l2vpn-svc>

   The example above describes a multi-VPN case where a site (SITE1) has
   two logical accesses (LA1 and LA2), attached to both VPNA and VPNB.

5.5.2.2.  VPN Policy

   The "vpn-policy" list helps express a multi-VPN scenario where a
   logical access belongs to multiple VPNs.

   As a site can belong to multiple VPNs, the vpn-policy list may be
   composed of multiple entries.  A filter can be applied to specify
   that only some LANs at the site should be part of a particular VPN.
   A site can be composed by multiple LAN segments and each LAN segment
   can be connected to different VPN.  Each time a site (or LAN) is
   attached to a VPN, the user must precisely describe its role (site-
   role) within the target VPN service topology.

      +--------------------------------------------------------------+
      |       Site1 ------ PE7                                       |
      +-------------------------+                 [VPN2]             |
                                |                                    |
      +-------------------------+                                    |
      |       Site2 ------ PE3               PE4 ------ Site3        |
      +----------------------------------+                           |
                                         |                           |
      +------------------------------------------------------------+ |
      |       Site4 ------ PE5           |   PE6 ------ Site5      | |
      |                                                            | |
      |                      [VPN3]                                | |
      +------------------------------------------------------------+ |
                                         |                           |
                                         +---------------------------+

   In the example above, Site5 is part of two VPNs: VPN3 and VPN2.  It
   will play a Hub role in VPN2 and an any-to-any role in VPN3.  We can
   express such a multi-VPN scenario as follows:

   <?xml version="1.0"?>
    <l2vpn-svc xmlns="urn:ietf:params:xml:ns:yang:ietf-l2vpn-svc">
     <vpn-services>
      <vpn-service>
       <vpn-id>VPN2</vpn-id>
       <ce-vlan-preservation>true</ce-vlan-preservation>
       <ce-vlan-cos-preservation>true</ce-vlan-cos-preservation>
      </vpn-service>
      <vpn-service>



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       <vpn-id>VPN3</vpn-id>
       <ce-vlan-preservation>true</ce-vlan-preservation>
       <ce-vlan-cos-preservation>true</ce-vlan-cos-preservation>
      </vpn-service>
     </vpn-services>
     <sites>
        <site>
       <locations>
        <location>
         <location-id>L1</location-id>
        </location>
       </locations>
       <management>
        <type>customer-managed</type>
       </management>
          <site-id>Site5</site-id>
          <vpn-policies>
           <vpn-policy>
            <vpn-policy-id>POLICY1</vpn-policy-id>
            <entries>
             <id>ENTRY1</id>
             <vpn>
              <vpn-id>VPN2</vpn-id>
              <site-role>hub-role</site-role>
             </vpn>
            </entries>
            <entries>
             <id>ENTRY2</id>
             <vpn>
              <vpn-id>VPN3</vpn-id>
              <site-role>any-to-any-role</site-role>
             </vpn>
            </entries>
           </vpn-policy>
          </vpn-policies>
          <site-network-accesses>
           <site-network-access>
            <network-access-id>LA1</network-access-id>
         <site>
          <site-id>SITE1</site-id>
       <locations>
        <location>
         <location-id>L1</location-id>
        </location>
       </locations>
       <management>
        <type>customer-managed</type>
       </management>



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          <site-network-accesses>
           <site-network-access>
            <network-access-id>LA1</network-access-id>
                <service>
                  <svc-bandwidth>
                     <bandwidth>
                       <direction>input-bw</direction>
                        <type>bw-per-cos</type>
                         <cir>450000000</cir>
                         <cbs>20000000</cbs>
                         <eir>1000000000</eir>
                         <ebs>200000000</ebs>
                      </bandwidth>
                    </svc-bandwidth>
                     <carrierscarrier>
                       <signaling-type>bgp</signaling-type>
                     </carrierscarrier>
                     <svc-mtu>1514<svc-mtu>
                   </service>
            <vpn-attachment>
             <vpn-id>VPNA</vpn-id>
             <site-role>spoke-role</site-role>
            </vpn-attachment>
           </site-network-access>
           <site-network-access>
            <network-access-id>LA2</network-access-id>
                <service>
                  <svc-bandwidth>
                     <bandwidth>
                       <direction>input-bw</direction>
                        <type>bw-per-cos</type>
                         <cir>450000000</cir>
                         <cbs>20000000</cbs>
                         <eir>1000000000</eir>
                         <ebs>200000000</ebs>
                     </bandwidth>
                    </svc-bandwidth>
                     <carrierscarrier>
                       <signaling-type>bgp</signaling-type>
                     </carrierscarrier>
                     <svc-mtu>1514<svc-mtu>
                   </service>
            <vpn-attachment>
             <vpn-id>VPNB</vpn-id>
             <site-role>spoke-role</site-role>
            </vpn-attachment>
           </site-network-access>
          </site-network-accesses>



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         </site>
            <vpn-attachment>
             <vpn-policy-id>POLICY1</vpn-policy-id>
            </vpn-attachment>
           </site-network-access>
          </site-network-accesses>
         </site>
     </sites>
    </l2vpn-svc>

   Now, if a more-granular VPN attachment is necessary, filtering can be
   used.  For example, if LAN1 from Site5 must be attached to VPN2 as a
   Hub and LAN2 must be attached to VPN3, the following configuration
   can be used:

    <?xml version="1.0"?>
      <l2vpn-svc xmlns="urn:ietf:params:xml:ns:yang:ietf-l2vpn-svc">
        <vpn-services>
          <vpn-service>
            <vpn-id>VPN2</vpn-id>
            <ce-vlan-preservation>true</ce-vlan-preservation>
            <ce-vlan-cos-preservation>true</ce-vlan-cos-preservation>
            </vpn-service>
            <vpn-service>
             <vpn-id>VPN3</vpn-id>
             <ce-vlan-preservation>true</ce-vlan-preservation>
             <ce-vlan-cos-preservation>true</ce-vlan-cos-preservation>
            </vpn-service>
        </vpn-services>
       <site>
       <locations>
        <location>
         <location-id>L1</location-id>
        </location>
       </locations>
       <management>
        <type>customer-managed</type>
       </management>
             <site-id>Site5</site-id>
             <vpn-policies>
              <vpn-policy>
               <vpn-policy-id>POLICY1</vpn-policy-id>
               <entries>
                <id>ENTRY1</id>
                <filters>
                  <filter>
                    <type>lan</type>
                    <lan-tag>LAN1</lan-tag>



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                  </filter>
                </filters>
                <vpn>
                 <vpn-id>VPN2</vpn-id>
                 <site-role>hub-role</site-role>
                </vpn>
               </entries>
               <entries>
                <id>ENTRY2</id>
                <filters>
                  <filter>
                    <type>lan</type>
                    <lan-tag>LAN2</lan-tag>
                  </filter>
                </filters>
                 <vpn>
                 <vpn-id>VPN3</vpn-id>
                 <site-role>any-to-any-role</site-role>
                </vpn>
               </entries>
              </vpn-policy>
             </vpn-policies>
             <site-network-accesses>
              <site-network-access>
               <network-access-id>LA1</network-access-id>
                 <service>
                   <svc-bandwidth>
                     <bandwidth>
                       <direction>input-bw</direction>
                       <type>bw-per-cos</type>
                        <cir>450000000</cir>
                        <cbs>20000000</cbs>
                         <eir>1000000000</eir>
                         <ebs>200000000</ebs>
                      </bandwidth>
                     </svc-bandwidth>
                      <carrierscarrier>
                         <signaling-type>bgp</signaling-type>
                      </carrierscarrier>
                       <svc-mtu>1514<svc-mtu>
                   </service>
               <vpn-attachment>
                <vpn-policy-id>POLICY1</vpn-policy-id>
               </vpn-attachment>
              </site-network-access>
             </site-network-accesses>
            </site>
           </sites>



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         </l2vpn-svc>

5.6.  Deciding Where to Connect the Site

   The management system will have to determine where to connect each
   site-network-access of a particular site to the provider network
   (e.g., PE or aggregation switch).

   This model defines parameters and constraints that can influence the
   meshing of the site-network-access.

   The management system MUST honor all customer constraints, or if a
   constraint is too strict and cannot be fulfilled, the management
   system MUST NOT provision the site and MUST provide information to
   the user about which constraints that could not be fulfilled.  How
   the information is provided is out of scope for this document.
   Whether or not to relax the constraint would then be left up to the
   user.

   Parameters such as site location (see Section 5.6.2) and access type
   (see Section 5.6.3) affect the service placement that the management
   system applies.

   In addition to parameters and constraints, the management system's
   decision MAY be based on any other internal constraints that are left
   up to the SP, such as least load, distance, etc.

5.6.1.  Constraint: Device

   In the case of provider management or co-management, one or more
   devices have been ordered by the customer to a particular location
   that has already been configured.  The customer may force a
   particular site-network-access to be connected on a particular device
   that he ordered.

             New York Site
        +------------------+             Site
        | +--------------+ |-----------------------------------
        | | Manhattan    | |
        | |           CE1********* (site-network-access#1) ******
        | +--------------+ |
        | +--------------+ |
        | | Brooklyn     | |
        | |           CE2********* (site-network-access#2) ******
        | +--------------+ |
        |                  |-----------------------------------
        +------------------+




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   In the figure above, site-network-access#1 is associated with CE1 in
   the service request.  The SP must ensure the provisioning of this
   connection.

5.6.2.  Constraint/Parameter: Site Location

   The location information provided in this model MAY be used by a
   management system to determine the target PE to mesh the site (SP
   side).  A particular location must be associated with each site
   network access when configuring it.  The SP MUST honor the
   termination of the access on the location associated with the site
   network access (customer side).  The "country-code" in the site
   location should be expressed as an ISO 3166 code and is similar to
   country label defined in [RFC4119].

   The site-network-access location is determined by the "location-
   flavor".  In the case of a provider-managed or co-managed site, the
   user is expected to configure a "device-reference" (device case) that
   will bind the site-network-access to a particular device that the
   customer ordered.  As each device is already associated with a
   particular location, in such a case the location information is
   retrieved from the device location.  In the case of a customer-
   managed site, the user is expected to configure a "location-
   reference" (location case); this provides a reference to an existing
   configured location and will help with placement.

                                            POP#1 (New York)
                                         +---------+
                                         |   PE1   |
                    Site #1 ---...       |   PE2   |
                   (Atlantic City)       |   PE3   |
                                         +---------+

                                            POP#2 (Washington)
                                         +---------+
                                         |   PE4   |
                                         |   PE5   |
                                         |   PE6   |
                                         +---------+

                                            POP#3 (Philadelphia)
                                         +---------+
                                         |   PE7   |
                    Site #2 CE#1---...   |   PE8   |
                   (Reston)              |   PE9   |
                                         +---------+





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   In the example above, Site #1 is a customer-managed site with a
   location L1, while Site #2 is a provider-managed site for which a CE
   (CE#1) was ordered.  Site #2 is configured with L2 as its location.
   When configuring a site-network-access for Site #1, the user will
   need to reference location L1 so that the management system will know
   that the access will need to terminate on this location.  Then, for
   distance reasons, this management system may mesh Site #1 on a PE in
   the Philadelphia POP.  It may also take into account resources
   available on PEs to determine the exact target PE (e.g., least
   loaded).  For Site #2, the user is expected to configure the site-
   network-access with a device-reference to CE#1 so that the management
   system will know that the access must terminate on the location of
   CE#1 and must be connected to CE#1.  For placement of the SP side of
   the access connection, in the case of the nearest PE used, it may
   mesh Site #2 on the Washington POP.

5.6.3.  Constraint/Parameter: Access Type

   The management system needs to elect the access media to connect the
   site to the customer (for example, xDSL, leased line, Ethernet
   backhaul).  The customer may provide some parameters/constraints that
   will provide hints to the management system.

   The bearer container information SHOULD be the first piece of
   information considered when making this decision:

   o  The "requested-type" parameter provides information about the
      media type that the customer would like to use.  If the "strict"
      leaf is equal to "true", this MUST be considered a strict
      constraint so that the management system cannot connect the site
      with another media type.  If the "strict" leaf is equal to "false"
      (default) and if the requested media type cannot be fulfilled, the
      management system can select another media type.  The supported
      media types SHOULD be communicated by the SP to the customer via a
      mechanism that is out of scope for this document.

   o  The "always-on" leaf defines a strict constraint: if set to true,
      the management system MUST elect a media type that is "always-on"
      (e.g., this means no dial access type).

   o  The "bearer-reference" parameter is used in cases where the
      customer has already ordered a network connection to the SP apart
      from the L2VPN site and wants to reuse this connection.  The
      string used is an internal reference from the SP and describes the
      already-available connection.  This is also a strict requirement
      that cannot be relaxed.  How the reference is given to the
      customer is out of scope for this document, but as an example,
      when the customer ordered the bearer (through a process that is



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      out of scope for this model), the SP may have provided the bearer
      reference that can be used for provisioning services on top.

   Any other internal parameters from the SP can also be used.  The
   management system MAY use other parameters, such as the requested
   "svc-input-bandwidth" and "svc-output-bandwidth", to help decide
   which access type to use.

5.6.4.  Constraint: Access Diversity

   Each site-network-access may have one or more constraints that would
   drive the placement of the access.  By default, the model assumes
   that there are no constraints, but allocation of a unique bearer per
   site-network-access is expected.

   In order to help with the different placement scenarios, a site-
   network-access may be tagged using one or multiple group identifiers.
   The group identifier is a string, so it can accommodate both explicit
   naming of a group of sites (e.g., "multihomed-set1") and the use of a
   numbered identifier (e.g., 12345678).  The meaning of each group-id
   is local to each customer administrator, and the management system
   MUST ensure that different customers can use the same group-ids.  One
   or more group-ids can also be defined at the site level; as a
   consequence, all site-network-accesses under the site MUST inherit
   the group-ids of the site they belong to.  When, in addition to the
   site group-ids some group-ids are defined at the site-network-access
   level, the management system MUST consider the union of all groups
   (site level and site network access level) for this particular site-
   network-access.

   For an already-configured site-network-access, each constraint MUST
   be expressed against a targeted set of site-network-accesses.  This
   site-network-access (i.e. the already-configured site-network-access)
   MUST never be taken into account in the targeted set of site-network-
   accesses.  For example, "My site-network-access S must not be
   connected on the same POP as the site-network-accesses that are part
   of Group 10."  The set of site-network-accesses against which the
   constraint is evaluated can be expressed as a list of groups, "all-
   other-accesses", or "all-other-groups".  The all-other-accesses
   option means that the current site-network-access constraint MUST be
   evaluated against all the other site-network-accesses belonging to
   the current site.  The all-other-groups option means that the
   constraint MUST be evaluated against all groups that the current
   site-network-access does not belong to.

   The current model defines multiple constraint-types:





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   o  pe-diverse: The current site-network-access MUST NOT be connected
      to the same PE as the targeted site-network-accesses.

   o  pop-diverse: The current site-network-access MUST NOT be connected
      to the same POP as the targeted site-network-accesses.

   o  linecard-diverse: The current site-network-access MUST NOT be
      connected to the same linecard as the targeted site-network-
      accesses.  Note that customer can request lincard-diverse for
      site-network-accesses, but the specific linecard identifier used
      should not be exposed to customer.

   o  bearer-diverse: The current site-network-access MUST NOT use
      common bearer components compared to bearers used by the targeted
      site-network-accesses. "bearer-diverse" provides some level of
      diversity at the access level.  As an example, two bearer-diverse
      site-network-accesses must not use the same DSLAM, BAS, or Layer 2
      switch.

   o  same-pe: The current site-network-access MUST be connected to the
      same PE as the targeted site-network-accesses.

   o  same-bearer: The current site-network-access MUST be connected
      using the same bearer as the targeted site-network-accesses.

   These constraint-types can be extended through augmentation.  Each
   constraint is expressed as "The site-network-access S must be
   <constraint-type> (e.g., pe-diverse, pop-diverse) from these <target>
   site-network-accesses."

   The group-id used to target some site-network-accesses may be the
   same as the one used by the current site-network-access.  This eases
   the configuration of scenarios where a group of site-network-access
   points has a constraint between the access points in the group.

5.7.  Route Distinguisher and Network Instance Allocation

   The route distinguisher (RD) is a critical parameter of BGP-based
   L2VPNs as described in [RFC4364] that provides the ability to
   distinguish common addressing plans in different VPNs.  As for route
   targets (RTs), a management system is expected to allocate a MAC-VRF
   on the target PE and an RD for this MAC-VRF.  This RD MUST be unique
   across all MAC-VRFs on the target PE.

   If a MAC-VRF already exists on the target PE and the MAC-VRF fulfills
   the connectivity constraints for the site, there is no need to
   recreate another MAC-VRF, and the site MAY be meshed within this
   existing MAC-VRF.  How the management system checks that an existing



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   MAC-VRF fulfills the connectivity constraints for a site is out of
   scope for this document.

   If no such MAC-VRF exists on the target PE, the management system has
   to initiate the creation of a new MAC-VRF on the target PE and has to
   allocate a new RD for this new MAC-VRF.

   The management system MAY apply a per-VPN or per-MAC-VRF allocation
   policy for the RD, depending on the SP's policy.  In a per-VPN
   allocation policy, all MAC-VRFs (dispatched on multiple PEs) within a
   VPN will share the same RD value.  In a per-MAC-VRF model, all MAC-
   VRF should always have a unique RD value.  Some other allocation
   policies are also possible, and this document does not restrict the
   allocation policies to be used.

   The allocation of RDs MAY be done in the same way as RTs.  The
   examples provided in Section 5.2.2.1 could be reused in this
   scenario.

   Note that an SP MAY configure a target PE for an automated allocation
   of RDs.  In this case, there will be no need for any backend system
   to allocate an RD value.

5.8.  Site Network Access Availability

   A site may be multihomed, meaning that it has multiple site-network-
   access points.  Placement constraints defined in previous sections
   will help ensure physical diversity.

   When the site-network-accesses are placed on the network, a customer
   may want to use a particular routing policy on those accesses.  The
   "site-network-access/availability" container defines parameters for
   site redundancy.  The "access-priority" leaf defines a preference for
   a particular access.  This preference is used to model load-balancing
   or primary/backup scenarios.  The higher the access-priority value,
   the higher the preference will be.  The "redundancy mode" attribute
   is defined for an multi-homing site and used to model single-active
   and active/active scenarios.  It allows for multiple active paths in
   forwarding state and for load-balancing options.

   The figure below describes how the access-priority attribute can be
   used.









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      Hub#1 LAN (Primary/backup)          Hub#2 LAN (Load-sharing)
        |                                                     |
        |    access-priority 1          access-priority 1     |
        |--- CE1 ------- PE1            PE3 --------- CE3 --- |
        |                                                     |
        |                                                     |
        |--- CE2 ------- PE2            PE4 --------- CE4 --- |
        |    access-priority 2          access-priority 1     |

                                PE5
                                 |
                                 |
                                 |
                                CE5
                                 |
                            Spoke#1 site (Single-homed)

   In the figure above, Hub#2 requires load-sharing, so all the site-
   network-accesses must use the same access-priority value.  On the
   other hand, as Hub#1 requires a primary site-network-access and a
   backup site-network-access, a higher access-priority setting will be
   configured on the primary site-network-access.

   Scenarios that are more complex can also be modeled.  Let's consider
   a Hub site with five accesses to the network (A1, A2, A3, A4, and
   A5).  The customer wants to load-share its traffic on A1 and A2 in
   the nominal situation.  If A1 and A2 fail, the customer wants to
   load-share its traffic on A3 and A4; finally, if all of A1 to A4 are
   down, he wants to use A5.  We can model this easily by configuring
   the following access-priority values: A1=100, A2=100, A3=50, A4=50,
   A5=10.

   The access-priority scenario has some limitations.  An access-
   priority scenario like the previous one with five accesses but with
   the constraint of having traffic load-shared between A3 and A4 in the
   case where just one of A1 or A2 is down is not achievable.  But the
   access-priority attribute defined will cover most of the deployment
   use cases, and if necessary the model can be extended via
   augmentation to support additional use cases.

5.9.  SVC MTU

   The maximum MTU of subscriber service frames can be derived from the
   physical interface MTU by default, or specified under the "svc-mtu"
   leaf if it is different than the default number.






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5.10.  Service

   The "service" container defines service parameters associated with
   the site.

5.10.1.  Bandwidth

   The service bandwidth refers to the bandwidth requirement between CE
   and PE and can be represented using Committed Information
   Rate(CIR),Excess Information Rate(EIR),Peak Information Rate(PIR).
   The requested bandwidth is expressed as ingress bandwidth and egress
   bandwidth.  Ingress/egress direction uses the customer site as the
   point of reference: Ingress direction bandwidth means download
   bandwidth for the site, and egresss bandwidth means upload bandwidth
   for the site.

   The service bandwidth is only configurable at the site-network-access
   level (i.e., for the site network access associated with the site).

   Using a different ingress and egress bandwidth will allow service
   provider to know if a customer allows for asymmetric bandwidth access
   like ADSL.  It can also be used to set the rate limit in a different
   way for upload and download on symmetric bandwidth access.

   The svc-bandwidth has specific type.  This document defines four
   types:

   o  bw-per-access Bandwidth is per connection or site network access,
      providing rate enforcement for all service frames at the interface
      that are associated with a particular network access.

   o  bw-per-cos Bandwidth is per cos, providing rate enforcement for
      all service frames for a given class of service with specific cos-
      id.

   o  bw-per-svc bandwidth is per site, providing rate enforcement for
      all service frames that are associated with a particular VPN
      service.

   o  opaque bandwidth is the total bandwidth that is not associated
      with any particular cos-id, vpn service identified with the vpn-
      id, or site network access id.

   The svc-bandwidth must include a "cos-id" parameter if the 'type' is
   set as 'bw-per-cos'.  The cos-id can be assigned based on the IEEE
   802.1p value in the C-tag, or on the DSCP in the Ethernet Frame
   header.  Service frames are metered against the bandwidth profile
   based on the cos-identifier.



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   The svc-bandwidth must be associated with a specific "site-network-
   access-id" parameter if the 'type' is set as 'bw-per-access'.
   Multiple bandwidths per cos-id can be associated with the same Site
   Network access.

   The svc-bandwidth must include a specific "vpn-id" parameter if the
   'type' is set as 'bw-per-svc'.  Multiple bandwidths per cos-id can be
   associated with the same Ethernet VPN service.

5.10.2.  QoS

   The model defines QoS parameters as an abstraction:

   o  qos-classification-policy: Defines a set of ordered rules to
      classify customer traffic.

   o  qos-profile: Provides a QoS scheduling profile to be applied.

5.10.2.1.  QoS Classification

   QoS classification rules are handled by qos-classification-policy.
   The qos-classification-policy is an ordered list of rules that match
   a flow or application and set the appropriate target class of service
   (target-class-id).  The user can define the match using a more
   specific flow definition (based on layer 2 source and destination MAC
   addresses, cos, dscp, cos-id, color-id, etc.).  A "color-id" will be
   assigned to a service frame to identify its QoS profile conformance.
   A service frame is "green" if it is conformant with the "committed"
   rate of the bandwidth profile.  A Service Frame is "yellow" if it is
   exceeding the "committed" rate, but conformant with the "excess" rate
   of the bandwidth profile.  Finally, a service frame is "red" if it is
   conformant with neither the "committed" nor "excess" rates of the
   bandwidth profile.

   When a flow definition is used, the user can use a target-sites leaf-
   list to identify the destination of a flow rather than using
   destination addresses.  In such a case, an association between the
   site abstraction and the MAC addresses used by this site must be done
   dynamically.  How this association is done is out of scope for this
   document.  The association of a site to an L2VPN is done through the
   "vpn-attachment" container.  Therefore, the user can also employ the
   "target-sites" leaf-list and "vpn-attachment" to identify the
   destination of a flow targeted to specific VPN service.  A rule that
   does not have a match statement is considered as a match-all rule.  A
   service provider may implement a default terminal classification rule
   if the customer does not provide it.  It will be up to the service
   provider to determine its default target class.  This model defines
   some applications, but new application identities may be added



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   through augmentation.  The exact meaning of each application identity
   is up to the SP, so it will be necessary for the SP to advise the
   customer on the usage of application matching.

5.10.2.2.  QoS Profile

   A user can choose between the standard profile provided by the
   operator or a custom profile.  The qos-profile defines the traffic
   scheduling policy to be used by the service provider.

   A custom qos-profile is defined as a list of class of services and
   associated properties.  The properties are:

   o  direction: Used to specify the direction to which the qos-profile
      is applied.  This model supports "Site-to-WAN" direction, "WAN-to-
      Site" direction, and "both" directions.  By default, "both"
      directions is used.  In case of "both" directions, the provider
      should ensure scheduling according to the requested policy in both
      traffic directions (SP to customer, and customer to SP).  As an
      example, a device-scheduling policy may be implemented on both the
      PE side and the CE side of the WAN link.  In case of "WAN-to-Site"
      direction, the provider should ensure scheduling from the SP
      network to the customer site.  As an example, a device- scheduling
      policy may be implemented only on the PE side of the WAN link
      towards the customer.

   o  policing: The optional "policing" indicates whether policing
      should apply to one-rate two-colors or to two-rates three-colors.

   o  byte-offset: The optional "byte-offset" indicates how many bytes
      in the service frame header are excluded from rate enforcement.

   o  frame-delay: Used to define the latency constraint of the class.
      The latency constraint can be expressed as the lowest possible
      latency, or as a latency boundary expressed in milliseconds.  How
      this latency constraint will be fulfilled is up to the service
      provider implementation: a strict priority queueing mechanism may
      be used on the access and in the core network, or a low latency
      routing path may be created for this traffic class.

   o  frame-jitter: Used to define the jitter constraint of the class.
      The jitter constraint can be expressed as the lowest possible
      jitter, or as a jitter boundary expressed in microseconds.  How
      this jitter constraint will be fulfilled is up to the service
      provider implementation: a strict priority queueing mechanism may
      be used on the access and in the core network, or a jitter-aware
      routing path may be created for this traffic class.




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   o  bandwidth: used to define a guaranteed amount of bandwidth for the
      class of service.  It is expressed as a percentage.  The
      "guaranteed-bw-percent" parameter uses available bandwidth as a
      reference.  The available bandwidth should not fall below the
      Committed Information Rate (CIR) defined under svc-input-bandwidth
      or svc-output-bandwidth.  When the qos-profile container is
      implemented on the CE side, svc-output-bandwidth is taken into
      account as a reference.  When it is implemented on the PE side,
      svc-input-bandwidth is used.  By default, the bandwidth
      reservation is only guaranteed at the access level.  The user can
      use the "end-to-end" leaf to request an end-to-end bandwidth
      reservation, including across the MPLS transport network.  (In
      other words, the SP will activate something in the MPLS core to
      ensure that the bandwidth request from the customer will be
      fulfilled by the MPLS core as well.)  How this is done (e.g.,
      RSVP-TE reservation, controller reservation) is out of scope for
      this document.

   In addition, due to network conditions, some constraints may not be
   completely fulfilled by the SP; in this case, the SP should advise
   the customer about the limitations.  How this communication is done
   is out of scope for this document.

5.10.3.  Broadcast Multicast Unknow Unicast Support

   The "broadcast-unknown-unicast-multicast" container defines the type
   of site in the customer multicast service topology: source, receiver,
   or both.  These parameters will help the management system optimize
   the multicast service.

   Multiple multicast group-to-port mappings can be created using the
   "multicast-gp-address-mapping" list.  The "multicast-gp-address-
   mapping" defines multicast group address and port LAG number.  Those
   parameters will help the SP select the appropriate association
   between interface and multicast group to fulfill the customer service
   requirement.

   A whole Layer-2 multicast frame (whether for data or control) should
   not be altered from a CE to CEs except for the VLAN ID field,
   ensuring that it is transparently transported.  If VLAN IDs are
   assigned by the SP, they can also be altered.

   For point-to-point services, the provider only needs to deliver a
   single copy of each service frame to the remote PE, regardless
   whether the destination MAC address of the incoming frame is unicast,
   multicast or broadcast.  Therefore, all service frames should be
   delivered unconditionally.




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   BUM (Broadcast-UnknownUnicast-Multicast) frame forwarding in
   multipoint-to-multipoint services, on the other hand, involves both
   local flooding to other attachment circuits on the same PE and remote
   replication to all other PEs, thus consumes additional resources and
   core bandwidth.  Special BUM frame disposition rules can be
   implemented at external facing interfaces (UNI or E-NNI) to rate-
   limit the BUM frames, in term of number of packets per second or bits
   per second.

   The threshold can apply to all BUM traffic, or one for each category.

5.11.  Site Management

   The "management" sub-container is intended for site management
   options, depending on the device ownership and security access
   control.  The followings are three common management models:

   CE Provider Managed:  The provider has the sole ownership of the CE
      device.  Only the provider has access to the CE.  The
      responsibility boundary between SP and customer is between CE and
      customer network.  This is the most common use case.

   CE Customer Managed:  The customer has the sole ownership of the CE
      device.  Only the customer has access to the CE.  In this model,
      the responsibility boundary between SP and customer is between PE
      and CE.

   CE Co-managed:  The provider has ownership of the CE device and
      responsible for managing the CE.  However, the provider grants the
      customer access to the CE for some configuration/monitoring
      purposes.  In this co-managed mode, the responsibility boundary is
      the same as for the provider-managed model.

   The selected management mode is specified under the "type" leaf.  The
   "address" leaf stores CE device management addressing information.
   And the "management-transport" leaf is used to identify the transport
   protocol for management traffic: IPv4 or IPv6.  Additional security
   options may be derived based on the particular management model
   selected.

5.12.  MAC Loop Protection

   MAC address flapping between different physical ports typically
   indicates a bridge loop condition in the customer network.
   Misleading entries in the MAC cache table can cause service frames to
   circulate around the network indefinitely and saturate the links
   throughout the provider's network, affecting other services in the




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   same network.  In case of EVPN, it also introduces massive BGP
   updates and control plane instability.

   The service provider may opt to implement a switching loop prevention
   mechanism at the external facing interfaces for multipoint-to-
   multipoint services by imposing a MAC address move threshold.

   The MAC move rate and prevention-type options are listed in the "mac-
   loop-prevention" container.

5.13.  MAC Address Limit

   The optional "mac-address-limit" container contains the customer MAC
   address limit and information to describe the action when the limit
   is exceeded and the aging time for a MAC address.

   When multiple services are provided on the same network element, the
   MAC address table (and the Routing Information Base space for MAC-
   routes in the case of EVPN) is a shared common resource.  Service
   providers may impose a maximum number of MAC addresses learned from
   the customer for a single service instance by using 'mac-limit'leaf,
   and may use 'action' leaf to specify the action when the upper limit
   is exceeded: drop the packet, flood the packet, or simply send a
   warning log message.

   For point-to-point services, if MAC learning is disabled then the MAC
   address limit is not necessary.

5.14.  Enhanced VPN Features

5.14.1.  Carriers' Carriers

   In the case of Carriers' Carrier (CsC) [RFC6624], a customer may want
   to build an MPLS service using an L2VPN to carry its traffic.

















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               LAN customer1
                  |
                  |
                 CE1
                  |
                  | -------------
               (vrf_cust1)
                CE1_ISP1
                  |                 ISP1 POP
                  | MPLS link
                  | -------------
                  |
               (vrf ISP1)
                 PE1

                (...)               Provider backbone

                 PE2
                (vrf ISP1)
                  |
                  | ------------
                  |
                  | MPLS link
                  |                 ISP1 POP
                 CE2_ISP1
                 (vrf_cust1)
                  | ------------
                  |
                 CE2
                  |
               LAN customer1

   In the figure above, ISP1 resells an L2VPN service but has no core
   network infrastructure between its POPs.  ISP1 uses an L2VPN as the
   core network infrastructure (belonging to another provider) between
   its POPs.

   In order to support CsC, the VPN service must indicate MPLS support
   by setting the "carrierscarrier" leaf to true in the vpn-service
   list.  The link between CE1_ISP1/PE1 and CE2_ISP1/PE2 must also run
   an MPLS signalling protocol.  This configuration is done at the site
   level.

   In this model, LDP or BGP can be used as the MPLS signalling
   protocol.  In the case of LDP, an IGP routing protocol MUST also be
   activated.  In the case of BGP signalling, BGP MUST also be
   configured as the routing protocol.




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   If CsC is enabled, the requested "svc-mtu" leaf will refer to the
   MPLS MTU and not to the link MTU.

5.15.  External ID References

   The service model sometimes refers to external information through
   identifiers.  As an example, to order cloud-access to a particular
   cloud service provider (CSP), the model uses an identifier to refer
   to the targeted CSP.  If a customer is directly using this service
   model as an API (through RESTCONF or NETCONF, for example) to order a
   particular service, the SP should provide a list of authorized
   identifiers.  In the case of cloud-access, the SP will provide the
   associated identifiers for each available CSP.  The same applies to
   other identifiers, such as std-qos-profile.

   As an usage example, the remote-carrier-name is used in the NNI case
   because it should be known by the current L2VPN Service Provider it
   is connecting.  While cloud-identifier should be known by both the
   current L2VPN Service Provider and the customer because it is applied
   to public cloud or internet access.

   How an SP provides the meanings of those identifiers to the customer
   is out of scope for this document.

5.16.  Defining NNIs and Inter-AS support

   An autonomous system (AS) is a single network or group of networks
   that is controlled by a common system administration group and that
   uses a single, clearly defined routing protocol.  In some cases, VPNs
   need to span different ASes in different geographic areas or span
   different SPs.  The connection between ASes is established by the SPs
   and is seamless to the customer.  Examples include:

   o  A partnership between SPs (e.g., carrier, cloud) to extend their
      VPN services seamlessly.

   o  An internal administrative boundary within a single SP (e.g.,
      backhaul versus core versus data center).

   NNIs have to be defined to extend the VPNs across multiple ASes.
   [RFC4761] defines multiple flavors of VPN NNI implementation.  Each
   implementation has pros and cons; this topic is outside the scope of
   this document.  For example, in an Inter-AS option A, autonomous
   system border router (ASBR) peers are connected by multiple
   interfaces with at least one of those interfaces spanning the two
   ASes while being present in the same VPN.  In order for these ASBRs
   to signal label blocks, they associate each interface with a Virtual
   Switching (MAC-VRF) instance and a BGP session.  As a result, traffic



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   between the back-to-back VPLS is Ethernet.  In this scenario, the
   VPNs are isolated from each other, and because the traffic is
   Ethernet, QoS mechanisms that operate on Ethernet traffic can be
   applied to achieve customer service level agreements (SLAs).

      --------                 --------------              -----------
     /        \               /              \            /           \
    | Cloud    |             |                |          |             |
    | Provider |-----NNI-----|                |----NNI---| Data Center |
    |  #1      |             |                |          |             |
     \        /              |                |           \           /
      --------               |                |            -----------
                             |                |
      --------               |   My network   |           -----------
     /        \              |                |          /           \
    | Cloud    |             |                |         |             |
    | Provider |-----NNI-----|                |---NNI---|  L2VPN      |
    |  #2      |             |                |         |  Partner    |
     \        /              |                |         |             |
      --------               |                |         |             |
                              \              /          |             |
                               --------------            \           /
                                     |                    -----------
                                     |
                                    NNI
                                     |
                                     |
                             -------------------
                            /                   \
                           |                     |
                           |                     |
                           |                     |
                           |     L2VPN Partner   |
                           |                     |
                            \                   /
                             -------------------

   The figure above describes an SP network called "My network" that has
   several NNIs.  This network uses NNIs to:

   o  increase its footprint by relying on L2VPN partners.

   o  connect its own data center services to the customer L2VPN.

   o  enable the customer to access its private resources located in a
      private cloud owned by some CSPs.





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5.16.1.  Defining an NNI with the Option A Flavor

              AS A                                         AS B
       -------------------                         -------------------
      /                   \                       /                   \
     |                     |                     |                     |
     |                 ++++++++ Inter-AS link +++++++++                |
     |                 +      +_______________+       +                |
     |                 +(MAC-VRF1)--(VPN1)--(MAC-VRF1)+                |
     |                 +      +               +       +                |
     |                 + ASBR +               + ASBR  +                |
     |                 +      +               +       +                |
     |                 +(MAC-VRF2)--(VPN2)--(MAC-VRF2)+                |
     |                 +      +_______________+       +                |
     |                 ++++++++               +++++++++                |
     |                     |                     |                     |
     |                     |                     |                     |
     |                     |                     |                     |
     |                 ++++++++ Inter-AS link +++++++++                |
     |                 +      +_______________+       +                |
     |                 +(MAC-VRF1)--(VPN1)--(MAC-VRF1)+                |
     |                 +      +               +       +                |
     |                 + ASBR +               + ASBR  +                |
     |                 +      +               +       +                |
     |                 +(MAC-VRF2)--(VPN2)--(MAC-VRF2)+                |
     |                 +      +_______________+       +                |
     |                 ++++++++               +++++++++                |
     |                     |                     |                     |
     |                     |                     |                     |
      \                   /                       \                   /
       -------------------                         -------------------

   In option A, the two ASes are connected to each other with physical
   links on ASBRs.  For resiliency purposes, there may be multiple
   physical connections between the ASes.  A VPN connection -- physical
   or logical (on top of physical) -- is created for each VPN that needs
   to cross the AS boundary, thus providing a back-to-back VPLS model.

   From a service model's perspective, this VPN connection can be seen
   as a site.  Let's say that AS B wants to extend some VPN connections
   for VPN C on AS A.  The administrator of AS B can use this service
   model to order a site on AS A.  All connection scenarios could be
   realized using the features of the current model.  As an example, the
   figure above shows two physical connections that have logical
   connections per VPN overlaid on them.  This could be seen as a multi-
   VPN scenario.  Also, the administrator of AS B will be able to choose
   the appropriate routing protocol (e.g., E-BGP) to dynamically
   exchange routes between ASes.



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   This document assumes that the option A NNI flavor SHOULD re-use the
   existing VPN site modeling.

   Example: a customer wants its CSP A to attach its virtual network N
   to an existing L2VPN (VPN1) that he has from L2VPN SP B.

               CSP A                           L2VPN SP B
        -----------------                     -----------
       /                 \                   /           \
      |       |           |                 |             |
      |  VM --|       ++++++++     NNI    ++++++++++      |--- VPN1
      |       |       +      +____________+        +      |   Site#1
      |       |-------+(MAC-VRF1)-(VPN1)-(MAC-VRF1)+      |
      |       |       +      +            +        +      |
      |       |       + ASBR +            + ASBR   +      |
      |       |       +      +____________+        +      |
      |       |       ++++++++            ++++++++++      |
      |  VM --|           |                 |             |--- VPN1
      |       |Virtual    |                 |             |   Site#2
      |       |Network    |                 |             |
      |  VM --|           |                 |             |--- VPN1
      |       |           |                 |             |   Site#3
       \                 /                   \           /
        -----------------                     -----------
                                                   |
                                                   |
                                                  VPN1
                                                 Site#4

   To create the VPN connectivity, the CSP or the customer may use the
   L2VPN service model that SP B exposes.  We could consider that, as
   the NNI is shared, the physical connection (bearer) between CSP A and
   SP B already exists.  CSP A may request through a service model the
   creation of a new site with a single site-network-access (single-
   homing is used in the figure).  As a placement constraint, CSP A may
   use the existing bearer reference it has from SP A to force the
   placement of the VPN NNI on the existing link.  The XML below
   illustrates a possible configuration request to SP B:

    <?xml version="1.0"?>
   <l2vpn-svc xmlns="urn:ietf:params:xml:ns:yang:ietf-l2vpn-svc">
    <vpn-profiles>
     <valid-provider-identifiers>
      <qos-profile-identifier>
       <id>GOLD</id>
      </qos-profile-identifier>
      <qos-profile-identifier>
       <id>PLATINUM</id>



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      </qos-profile-identifier>
     </valid-provider-identifiers>
    </vpn-profiles>
    <vpn-services>
     <vpn-service>
      <vpn-id>VPN1</vpn-id>
      <ce-vlan-preservation>true</ce-vlan-preservation>
      <ce-vlan-cos-preservation>true</ce-vlan-cos-preservation>
     </vpn-service>
    </vpn-services>
    <sites>
         <site>
             <site-id>CSP_A_attachment</site-id>
              <locations>
               <location>
                 <location-id>NY1</location-id>
                 <city>NY</city>
                 <country-code>US</country-code>
              </location>
              </locations>
             <site-vpn-flavor>site-vpn-flavor-nni</site-vpn-flavor>
               <site-network-accesses>
                 <site-network-access>
                  <network-access-id>CSP_A_VN1</network-access-id>
                          <connection>
                          <encapsulation-type>vlan</encapsulation-type>
                          <eth-inf-type>tagged</eth-inf-type>
                           <tagged-interface>
                            <tagged-inf-type>dot1q </tagged-inf-type>
                            <dot1q-vlan-tagged>
                             <cvlan-id>17</cvlan-id>
                           </dot1q-vlan-tagged>
                           </tagged-interface>
                          </connection>
                            <service>
                              <svc-bandwidth>
                                <bandwidth>
                                <direction>input-bw</direction>
                                <type>bw-per-cos</type>
                                <cir>450000000</cir>
                                <cbs>20000000</cbs>
                                <eir>1000000000</eir>
                                <ebs>200000000</ebs>
                                </bandwidth>
                              </svc-bandwidth>
                              <carrierscarrier>
                                <signaling-type>bgp</signaling-type>
                             </carrierscarrier>



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                            </service>
                           <vpn-attachment>
                              <vpn-id>12456487</vpn-id>
                              <site-role>spoke-role</site-role>
                            </vpn-attachment>
                </site-network-access>
             </site-network-accesses>
             <management>
              <type>customer-managed</type>
             </management>
         </site>
    </sites>
   </l2vpn-svc>

   The case described above is different from a scenario using the
   cloud-accesses container, as the cloud-access provides a public cloud
   access while this example enables access to private resources located
   in a CSP network.

5.16.2.  Defining an NNI with the Option B Flavor

             AS A                                          AS B
       -------------------                         -------------------
      /                   \                       /                   \
     |                     |                     |                     |
     |                 ++++++++ Inter-AS link ++++++++                 |
     |                 +      +_______________+      +                 |
     |                 +      +               +      +                 |
     |                 + ASBR +<---MP-BGP---->+ ASBR +                 |
     |                 +      +               +      +                 |
     |                 +      +_______________+      +                 |
     |                 ++++++++               ++++++++                 |
     |                     |                     |                     |
     |                     |                     |                     |
     |                     |                     |                     |
     |                 ++++++++ Inter-AS link ++++++++                 |
     |                 +      +_______________+      +                 |
     |                 +      +               +      +                 |
     |                 + ASBR +<---MP-BGP---->+ ASBR +                 |
     |                 +      +               +      +                 |
     |                 +      +_______________+      +                 |
     |                 ++++++++               ++++++++                 |
     |                     |                     |                     |
     |                     |                     |                     |
      \                   /                       \                   /
       -------------------                         -------------------





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   In option B, the two ASes are connected to each other with physical
   links on ASBRs.  For resiliency purposes, there may be multiple
   physical connections between the ASes.  The VPN "connection" between
   ASes is done by exchanging VPN routes through MP-BGP [RFC4761].

   There are multiple flavors of implementations of such an NNI.  For
   example:

   1.  The NNI is internal to the provider and is situated between a
       backbone and a data center.  There is enough trust between the
       domains to not filter the VPN routes.  So, all the VPN routes are
       exchanged.  RT filtering may be implemented to save some
       unnecessary route states.

   2.  The NNI is used between providers that agreed to exchange VPN
       routes for specific RTs only.  Each provider is authorized to use
       the RT values from the other provider.

   3.  The NNI is used between providers that agreed to exchange VPN
       routes for specific RTs only.  Each provider has its own RT
       scheme.  So, a customer spanning the two networks will have
       different RTs in each network for a particular VPN.

   Case 1 does not require any service modeling, as the protocol enables
   the dynamic exchange of necessary VPN routes.

   Case 2 requires that an RT-filtering policy on ASBRs be maintained.
   From a service modeling point of view, it is necessary to agree on
   the list of RTs to authorize.

   In Case 3, both ASes need to agree on the VPN RT to exchange, as well
   as how to map a VPN RT from AS A to the corresponding RT in AS B (and
   vice versa).

   Those modelings are currently out of scope for this document.
















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           CSP A                               L3VPN SP B

      -----------------                    ------------------
     /                 \                  /                  \
    |       |           |                |                    |
    |  VM --|       ++++++++   NNI    ++++++++                |--- VPN1
    |       |       +      +__________+      +                |   Site#1
    |       |-------+      +          +      +                |
    |       |       + ASBR +<-MP-BGP->+ ASBR +                |
    |       |       +      +__________+      +                |
    |       |       ++++++++          ++++++++                |
    |  VM --|           |                |                    |--- VPN1
    |       |Virtual    |                |                    |   Site#2
    |       |Network    |                |                    |
    |  VM --|           |                |                    |--- VPN1
    |       |           |                |                    |   Site#3
     \                 /                 |                    |
      -----------------                  |                    |
                                          \                  /
                                           ------------------
                                                    |
                                                    |
                                                   VPN1
                                                  Site#4

   The example above describes an NNI connection between CSP A and SP
   network B.  The SPs do not trust each other and use different RT
   allocation policies.  So, in terms of implementation, the customer
   VPN has a different RT in each network (RT A in CSP A and RT B in SP
   network B).  In order to connect the customer's virtual network in
   CSP A to the customer's L2VPN (VPN1) in SP network B, CSP A should
   request that SP network B open the customer VPN on the NNI (accept
   the appropriate RT).  Who does the RT translation depends on the
   agreement between the two SPs: SP B may permit CSP A to request VPN
   (RT) translation.

5.16.3.  Defining an NNI with the Option C Flavor














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             AS A                                           AS B
      -------------------                          -------------------
     /                   \                        /                   \
    |                     |                      |                     |
    |                     |                      |                     |
    |                     |                      |                     |
    |                 ++++++++ Multihop E-BGP ++++++++                 |
    |                 +      +                +      +                 |
    |                 +      +                +      +                 |
    |                 + RGW  +<----MP-BGP---->+ RGW  +                 |
    |                 +      +                +      +                 |
    |                 +      +                +      +                 |
    |                 ++++++++                ++++++++                 |
    |                     |                      |                     |
    |                     |                      |                     |
    |                     |                      |                     |
    |                     |                      |                     |
    |                     |                      |                     |
    |                 ++++++++ Inter-AS link ++++++++                  |
    |                 +      +_______________+      +                  |
    |                 +      +               +      +                  |
    |                 + ASBR +               + ASBR +                  |
    |                 +      +               +      +                  |
    |                 +      +_______________+      +                  |
    |                 ++++++++               ++++++++                  |
    |                     |                      |                     |
    |                     |                      |                     |
    |                     |                      |                     |
    |                 ++++++++ Inter-AS link ++++++++                  |
    |                 +      +_______________+      +                  |
    |                 +      +               +      +                  |
    |                 + ASBR +               + ASBR +                  |
    |                 +      +               +      +                  |
    |                 +      +_______________+      +                  |
    |                 ++++++++               ++++++++                  |
    |                     |                      |                     |
    |                     |                      |                     |
     \                   /                        \                   /
      -------------------                          -------------------

   From a VPN service's perspective, the option C NNI is very similar to
   option B, as an MP-BGP session is used to exchange VPN routes between
   the ASes.  The difference is that the forwarding plane and the
   control plane are on different nodes, so the MP-BGP session is
   multihop between routing gateway (RGW) nodes.  From a VPN service's
   point of view, modeling options B and C will be identical.





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5.17.  Applicability of L2SM model in Inter-Provider and Inter-Domain
       Orchestration

   In the case where the ASes belong to different providers, one might
   imagine that providers would like to have fewer signaling sessions
   crossing the AS boundary and that the entities that terminate the
   sessions could be restricted to a smaller set of devices.  Two
   approaches can be taken:

   a.  Inter-provider control connections to run only between the two
       border routers

   b.  Allow an end-to-end, multi-segment connectivity to be constructed
       out of several connectivity segments, without maintaining an end-
       to-end control connection.

   Inter-provider control connection described in (a) can be realized
   using techniques of Section 5.15 (i.e., defining NNI).  Multi-segment
   connectivity described in (b) can produce an inter-AS solution that
   more closely resembles option (b) in [RFC4364].  It may be realized
   using stitching of per-site connectivity and service segments at
   different domains, e.g., end-to-end connectivity between Site_1 and
   Site_3 spans multiple domains (e.g., Metro networks) and can be
   constructed by stitching network access connectivity within Site_1
   with SEG1, SEG3, SEG4 and network access connectivity within Site_3
   (as shown in the following figure).  The assumption is that service
   the orchestration component in Figure 3 should have visibility of the
   complete abstract topology and resource availability.  This may rely
   on network planning.

   Note that SEG1,SEG2,SEG3,SEG4,SEG5,SEG6 can also be regarded as
   network access connectivity within a site and can be created as a
   normal site using L2SM service model.

              ----------   ----------   ----------
             |          | |          | |          |
           +--+        +---+        +---+        +--+
     Site_1|PE|==SEG1==|   |==SEG3==|   |==SEG4==|PE|Site_3
           +--+        +---+        |   |        +--+
             |          | |         |   |         |  ----------
             |          | |         |   |         | |          |
           +--+        +---+        |   |        +---+        +--+
     Site_2|PE|==SEG2==|   |==SEG5==|   |==SEG6==|   |==SEG7==|PE|Site_4
           +--+        +---+        +---+        +---+        +--+
             |          | |          | |          | |          |
              ----------   ----------   ----------   ----------





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   In this figure, we use BGP redistribution of L2VPN NLRIs from AS to
   neighboring AS.  First, the PE routers use BGP to redistribute L2VPN
   NLRIs either to an ASBR, or to a route reflector of which an ASBR is
   a client.  The ASBR then uses BGP to redistribute those L2VPN NLRI to
   an ASBR in another AS, which in turn distributes them to the PE
   routers in that AS, or perhaps to another ASBR which in turn
   distributes them, and so on.

   In this case, a PE can learn the address of an ASBR through which it
   could reach another PE to which it wishes to establish a
   connectivity.  That is, a local PE will receive a BGP advertisement
   containing L2VPN NLRI corresponding to an L2VPN instance in which the
   local PE has some attached members.  The BGP next-hop for that L2VPN
   NLRI will be an ASBR of the local AS.  Then, rather than building a
   control connection all the way to the remote PE, it builds one only
   to the ASBR.  A connectivity segment can now be established from the
   PE to the ASBR.  The ASBR in turn can establish a connectivity to the
   ASBR of the next AS, and stitching that connectivity to the
   connectivity from the PE as described in [RFC6073].  Repeating the
   process at each ASBR leads to a sequence of connectivity segments
   that, when stitching together, connect the two PEs.

   Note that in the approach just described, the local PE may never
   learn the IP address of the remote PE.  It learns the L2VPN NLRI
   advertised by the remote PE, which need not contain the remote PE
   address, and it learns the IP address of the ASBR that is the BGP
   next hop for that NLRI.

   When this approach is used for VPLS, or for full-mesh VPWS, it leads
   to a full mesh of connectivity among the PEs, but it does not require
   a full mesh of control connections (LDP or L2TPv3 sessions).
   Instead, the control connections within a single AS run among all the
   PEs of that AS and the ASBRs of the AS.  A single control connection
   between the ASBRs of adjacent ASes can be used to support however
   many AS-to-AS connectivity segments are needed.

6.  Interaction with Other YANG Modules

   As expressed in Section 4, this service module is not intended to
   configure the network element, but is instantiated in a management
   system.

   The management system might follow modular design and comprise at
   least two different components:

   a.  The component instantiating the service model (let's call it the
       service component)




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   b.  The component responsible for network element configuration
       (let's call it the configuration component)

   In some cases, when a split is needed between the behavior and
   functions that a customer requests and the technology that the
   network operator has available to deliver the service [RFC8309], a
   new component can be separated out of the service component (let's
   call it the control component).  This component is responsible for
   network-centric operation and is aware of many features such as
   topology, technology, and operator policy.  As an optional component,
   it can use the service model as input and is not required at all if
   the control component delegates its control operations to the
   configuration component.

   In Section 7 we provide some example of translation of service
   provisioning requests to router configuration lines as an
   illustration.  In the YANG based ecosystem, it is expected that
   NETCONF and YANG will be used between the configuration component and
   network elements to configure the requested service on those
   elements.

   In this framework, it is expected that YANG models will be used for
   configuring service components on network elements.  There will be a
   strong relationship between the abstracted view provided by this
   service model and the detailed configuration view that will be
   provided by specific configuration models for network elements such
   as those defined in [I-D.ietf-bess-l2vpn-yang] and
   [I-D.ietf-bess-evpn-yang].  Service components needing configuration
   on network elements in support of the service model defined in this
   document include:

   o  Network Instance definition including VPN policy expression.

   o  Physical interface.

   o  Ethernet layer (VLAN ID).

   o  QoS: classification, profiles, etc.

   o  Ethernet Service OAM Support.

7.  Service Model Usage Example

   As explained in Section 4, this service model is intended to be
   instantiated at a management layer and is not intended to be used
   directly on network elements.  The management system serves as a
   central point of configuration of the overall service.




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   This section provides an example on how a management system can use
   this model to configure an L2VPN service on network elements.

   The example is to provide a VPN service for 3 sites using point-to-
   point VPWS and a Hub and Spoke VPN service topology as shown in
   Figure 5.  Loadbalancing is not considered in this case.

      Site1
      ............
      :          :             P2P VPWS
      :Spoke Site:-----PE1--------------------------+
      :          :                                  |        Site3
      :..........:                                  |      ............
                                                    |      :          :
                                                   PE3-----: Hub Site :
      Site2                                         |      :          :
      ............                                  |      :..........:
      :          :             P2P VPWS             |
      :Spoke Site:-----PE2--------------------------+
      :          :
      :..........:

              Figure 5: Reference Network for Simple Example

   The following XML describes the overall simplified service
   configuration of this VPN.

       <?xml version="1.0"?>
       <l2vpn-svc xmlns="urn:ietf:params:xml:ns:yang:ietf-l2vpn-svc">
         <vpn-services>
             <vpn-service>
              <vpn-id>12456487</vpn-id>
               <vpn-svc-type>vpws</vpn-svc-type>
               <svc-topo>hub-spoke</svc-topo>
               <ce-vlan-preservation>true</ce-vlan-preservation>
               <ce-vlan-cos-preservation>true</ce-vlan-cos-preservation>
              </vpn-service>
             <vpn-service>
               <vpn-id>12456488</vpn-id>
               <vpn-svc-type>vpws</vpn-svc-type>
               <svc-topo>hub-spoke</svc-topo>
               <ce-vlan-preservation>true</ce-vlan-preservation>
               <ce-vlan-cos-preservation>true</ce-vlan-cos-preservation>
              </vpn-service>
         </vpn-services>
       </l2vpn-svc>





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   When receiving the request for provisioning the VPN service, the
   management system will internally (or through communication with
   another OSS component) allocates VPN route-targets.  In this specific
   case two Route Targets (RTs) will be allocated (100:1 for Hubs and
   100:2 for Spokes).  The output below describes the configuration of
   Spoke Site1.

   <?xml version="1.0"?>
  <l2vpn-svc xmlns="urn:ietf:params:xml:ns:yang:ietf-l2vpn-svc">
   <vpn-services>
    <vpn-service>
     <vpn-id>12456487</vpn-id>
     <svc-topo>hub-spoke</svc-topo>
     <ce-vlan-preservation>true</ce-vlan-preservation>
     <ce-vlan-cos-preservation>true</ce-vlan-cos-preservation>
    </vpn-service>
   </vpn-services>
   <sites>
     <site>
        <site-id>Spoke_Site1</site-id>
           <locations>
             <location>
              <location-id>NY1</location-id>
              <city>NY</city>
              <country-code>US</country-code>
             </location>
            </locations>
            <site-network-accesses>
               <site-network-access>
                  <network-access-id>Spoke_UNI-Site1</network-access-id>
                    <access-diversity>
                      <groups>
                        <group>
                          <group-id>20</group-id>
                        </group>
                      </groups>
                    </access-diversity>
                      <connection>
                       <encapsulation-type>vlan</encapsulation-type>
                        <tagged-interface>
                        <dot1q-vlan-tagged>
                          <cvlan-id>17</cvlan-id>
                        </dot1q-vlan-tagged>
                        </tagged-interface>
                        <l2cp-control>
                          <stp-rstp-mstp>tunnel</stp-rstp-mstp>
                          <lldp>true</lldp>
                        </l2cp-control>



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                      </connection>
                      <service>
                        <svc-bandwidth>
                          <bandwidth>
                          <direction>input-bw</direction>
                          <type>bw-per-cos</type>
                          <cir>450000000</cir>
                          <cbs>20000000</cbs>
                          <eir>1000000000</eir>
                          <ebs>200000000</ebs>
                          </bandwidth>
                        </svc-bandwidth>
                        <carrierscarrier>
                         <signaling-type>bgp</signaling-type>
                        </carrierscarrier>
                     </service>
                      <vpn-attachment>
                        <vpn-id>12456487</vpn-id>
                        <site-role>spoke-role</site-role>
                      </vpn-attachment>
                    </site-network-access>
                  </site-network-accesses>
                  <management>
                    <type>provider-managed</type>
                  </management>
                </site>
          </sites>
      </l2vpn-svc>

   When receiving the request for provisioning the Spoke1 site, the
   management system MUST allocate network resources for this site.  It
   MUST first determine the target network elements to provision the
   access, and especially the PE router (and may be an aggregation
   switch).  As described in Section 5.3.1, the management system SHOULD
   use the location information and MUST use the access-diversity
   constraint to find the appropriate PE.  In this case, we consider
   Spoke1 requires PE diversity with Hub and that management system
   allocate PEs based on lowest distance.  Based on the location
   information, the management system finds the available PEs in the
   nearest area of the customer and picks one that fits the access-
   diversity constraint.

   When the PE is chosen, the management system needs to allocate
   interface resources on the node.  One interface is selected from the
   PE available pool.  The management system can start provisioning the
   PE node by using any mean (NETCONF, CLI, ...).  The management system
   will check if a VSI is already present that fits the needs.  If not,
   it will provision the VSI: the Route Distinguisher will come from the



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   internal allocation policy model, and the route-targets come from the
   vpn-policy configuration of the site (management system allocated
   some RTs for the VPN).  As the site is a Spoke site (site-role), the
   management system knows which RT must be imported and exported.  As
   the site is provider managed, some management route-targets may also
   be added (100:5000).  Standard provider VPN policies MAY also be
   added in the configuration.

   Example of generated PE configuration:

l2vpn vsi context one
  vpn id 12456487
     autodiscovery bgp signaling bgp
     ve id 1001      <----identify the PE routers within the VPLS domain
     ve range 50    <---- VE size
     route-distinguisher 100:3123234324
     route-target import 100:1
     route-target import 100:5000    <---- Standard SP configuration
     route-target export 100:2                 for provider managed CE
   !

   When the VSI has been provisioned, the management system can start
   configuring the access on the PE using the allocated interface
   information.  The tag or VLAN (e.g., service instance tag)is chosen
   by the management system.  One tag will be picked from an allocated
   subnet for the PE, another will be used for the CE configuration.
   LACP protocols will also be configured between PE and CE and due to
   provider managed model, the choice is up to service provider.  This
   choice is independent of the LACP protocol chosen by customer.

   Example of generated PE configuration:




















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   !
   bridge-domain 1
    member Ethernet0/0 service-instance 100
    member vsi one
   !
   l2 router-id 198.51.100.1
   !
   l2 router-id 2001:db8::10:1/64
   !

   interface Ethernet0/0
    no ip address
    service instance 100 ethernet
   encapsulation dot1q 100
    !

   !
   router bgp 1
    bgp log-neighbor-changes
    neighbor 198.51.100.4 remote-as 1
    neighbor 198.51.100.4 update-source Loopback0
    !
    address-family l2vpn vpls
     neighbor 198.51.100.4 activate
     neighbor 198.51.100.4 send-community extended
     neighbor 198.51.100.4 suppress-signaling-protocol ldp
     neighbor 2001:db8::0a10:4 activate
     neighbor 2001:db8::0a10:4 send-community extended
    exit-address-family

   !
   interface vlan 100 <-- Associating the Attachment
     no ip address       Circuit with the MAC-VRF at the PE
     xconnect vsi PE1-VPLS-A
   !
   vlan 100
     state active

   As the CE router is not reachable at this stage, the management
   system can produce a complete CE configuration that can be uploaded
   to the node by manual operation before sending the CE to customer
   premise.  The CE configuration will be built as for the PE.  Based on
   the CE type (vendor/model) allocated to the customer and bearer
   information, the management system knows which interface must be
   configured on the CE.  PE-CE link configuration is expected to be
   handled automatically using the service provider OSS as both
   resources are managed internally.  CE to LAN interface parameters
   like dot1Q tag are derived from the ethernet-connection taking into



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   account how management system distributes dot1Q tag between PE and CE
   within subnet.  This will allow to produce a plug'n'play
   configuration for the CE.

   Example of generated CE configuration:

                    interface Ethernet0/1
                      switchport trunk allowed vlan none
                      switchport mode trunk
                      service instance 100 ethernet
                      encapsulation default
                      l2protocol forward cdp
                      xconnect 203.0.113.1 100 encapsulation mpls
                    !

8.  YANG Module

<CODE BEGINS> file "ietf-l2vpn-svc@2018-04-03.yang"
module ietf-l2vpn-svc {
  yang-version 1.1;
  namespace "urn:ietf:params:xml:ns:yang:ietf-l2vpn-svc";
  prefix l2vpn-svc;

  import ietf-inet-types {
    prefix inet;
  }
  import ietf-yang-types {
    prefix yang;
  }
  import ietf-netconf-acm {
    prefix nacm;
  }

  organization
    "IETF L2SM Working Group.";
  contact
    "WG List: l2sm@ietf.org
     Editor: giuseppe.fioccola@telecomitalia.it";
  description
    "The YANG module defines a generic service configuration
     model for Layer 2 VPN services common across all of the
     vendor implementations.";

  revision 2018-04-03 {
    description
      "Initial revision";
    reference
      "RFC xxxx: A YANG Data Model for L2VPN Service



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       Delivery.";
  }

  feature carrierscarrier {
    description
      "Enables support of CsC.";
  }

  feature ethernet-oam {
    description
      "Enables support of ethernet OAM.";
  }

  feature extranet-vpn {
    description
      "Enable the Support of Extranet VPN.";
  }

  feature l2cp-control {
    description
      "Enable the Support of L2CP control.";
  }

  feature input-bw {
    description
      "Enable the suppport of Input Bandwidth in a VPN.";
  }

  feature output-bw {
    description
      "Enable the support of Output Bandwidth in a VPN";
  }

  feature uni-list {
    description
      "Enable the support of UNI list in a VPN.";
  }

  feature cloud-access {
    description
      "Allow VPN to connect to a Cloud Service
       provider or an internet service provider.";
  }

  feature oam-3ah {
    description
      "Enables the support of OAM 802.3ah.";
  }



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  feature micro-bfd {
    description
      "Enables the support of Micro-BFD.";

  }

  feature bfd {
    description
      "Enables the support of BFD.";
  }

  feature signaling-options {
    description
      "Enable the support of signaling option.";
  }

  feature site-diversity {
    description
      "Enables the support of site diversity constraints in a VPN.";
  }

  feature encryption {
    description
      "Enables support of encryption.";
  }

  feature always-on {
    description
      "Enables support for always-on access
       constraint.";
  }

  feature requested-type {
    description
      "Enables support for requested-type access
       constraint.";
  }

  feature bearer-reference {
    description
      "Enables support for bearer-reference access
       constraint.";
  }

  feature qos {
    description
      "Enables support of Class of Services.";
  }



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  feature qos-custom {
    description
      "Enables support of custom qos profile.";

  }

  feature lag-interface {
    description
      "Enable lag-interface.";
  }

  feature vlan {
    description
      "Enable the support of VLAN.";
  }

  feature dot1q {
    description
      "Enable the support of Dot1Q.";
  }

  feature sub-inf {
    description
      "Enable the support of Sub Interface.";
  }

  feature qinq {
    description
      "Enable the support of QinQ.";
  }

  feature qinany {
    description
      "Enable the support of QinAny.";
  }

  feature vxlan {
    description
      "Enable the support of VXLAN.";
  }

  feature lan-tag {
    description
      "Enables LAN Tag support in a VPN.";
  }

  feature target-sites {
    description



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      "Enables support of the 'target-sites' match flow parameter.";
  }

  feature bum {

    description
      "Enables broadcast,unknown-unicast,multicast
       capabilities in a VPN.";
  }

  feature mac-loop-prevention {
    description
      "Enables MAC Loop prevention capability in a VPN.";
  }

  feature lacp {
    description
      "Enables LACP capability in a VPN.";
  }

  feature mac-addr-limit{
    description
      "Enables MAC Address Limit capability in a VPN.";
  }

  feature acl {
    description
      "Enables ACL capability in a VPN. ";
  }

  feature cfm {
    description
      "Enables cfm 802.1 ag capability in a VPN.";
  }

  feature y-1731 {
    description
      "Enable Y.1731 capability in a VPN.";
 }

  typedef svc-id {
    type string;
    description
      "Defines a type of service component identifier.";
  }

  typedef ccm-priority-type {
    type uint8 {



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      range "0..7";
    }
    description
      "A 3 bits priority value to be used in the VLAN tag,
       if present in the transmitted frame.";

  }

  typedef control-mode {
    type enumeration {
      enum "peer" {
        description
          "Peer mode, i.e., participate in the protocol towards the CE.
           Peering is common for LACP  and E-LMI and occasionally
           for LLDP. For virtual private services the Subscriber
           can also request that the Service Provider peer
           spanning tree.";
      }
      enum "tunnel" {
        description
          "Tunnel mode,i.e.,pass to the egress or destination site.
           For EPL, the expectation is that L2CP frames are tunneled.";
      }
      enum "discard" {
        description
          "Discard mode,i.e.,discard the frame.";
      }
    }
    description
      "Defining a type of the control mode on L2CP protocols.";
  }

  typedef neg-mode {
    type enumeration {
      enum "full-duplex" {
        description
          "Defining Full duplex mode";
      }
      enum "auto-neg" {
        description
          "Defining Auto negotiation mode";
      }
    }
    description
      "Defining a type of the negotiation mode";
  }

  identity site-network-access-type {



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    description
      "Base identity for site-network-access type.";
  }

  identity point-to-point {
    base site-network-access-type;

    description
      "Identity for point-to-point connection.";
  }

  identity multipoint {
    base site-network-access-type;
    description
      "Identity for multipoint connection.
       Example: Ethernet broadcast segment.";
  }

  identity tag-type {
    description
      "Base identity from which all tag types
       are derived from";
  }

  identity c-vlan {
    base tag-type;
    description
      "A Customer-VLAN tag, normally using the 0x8100
       Ethertype";
  }

  identity s-vlan {
    base tag-type;
    description
      "A Service-VLAN tag.";
  }

  identity c-s-vlan {
    base tag-type;
    description
      "Using both Customer-VLAN tag and Service-VLAN tag.";
  }

  identity multicast-tree-type {
    description
      "Base identity for multicast tree type.";
  }




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  identity ssm-tree-type {
    base multicast-tree-type;
    description
      "Identity for SSM tree type.";
  }

  identity asm-tree-type {

    base multicast-tree-type;
    description
      "Identity for ASM tree type.";
  }

  identity bidir-tree-type {
    base multicast-tree-type;
    description
      "Identity for bidirectional tree type.";
  }

  identity mapping-type {
    description
      "Identity mapping-type";
  }

  identity static-mapping {
    base mapping-type;
    description
      "Identity for static mapping, i.e.,attach the interface
       to the Multicast group as static member";
  }

  identity dynamic-mapping {
    base mapping-type;
    description
      "Identity for dynamic mapping, i.e.,interface was added
       to the Multicast group as a result of snooping";
  }

  identity tf-type {
    description
      "Identity traffic-type";
  }

  identity multicast-traffic {
    base tf-type;
    description
      "Identity for multicast traffic";
  }



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  identity broadcast-traffic {
    base tf-type;
    description
      "Identity for broadcast traffic";
  }

  identity unknown-unicast-traffic {

    base tf-type;
    description
      "Identity for unknown unicast traffic";
  }

  identity encapsulation-type {
    description
      "Identity for encapsulation type";
  }

  identity ethernet {
    base encapsulation-type;
    description
      "Identity for ethernet type";
  }

  identity vlan {
    base encapsulation-type;
    description
      "Identity for VLAN  type";
  }

  identity carrierscarrier-type {
    description
      "Identity of carrierscarrier";
  }

  identity ldp {
    base carrierscarrier-type;
    description
      "Use LDP as the signalling protocol
       between the PE and the CE.";
  }

  identity bgp {
    base carrierscarrier-type;
    description
      "Use BGP (as per RFC 3107) as the signalling protocol
       between the PE and the CE.
       In this case, BGP must also be configured as



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       the routing protocol.";
  }

  identity eth-inf-type {
    description
      "Identity of Ethernet Interface Type.";
  }

  identity tagged {
    base eth-inf-type;
    description
      "Identity of tagged Interface type.";
  }

  identity untagged {
    base eth-inf-type;
    description
      "Identity of untagged Interface type.";
  }

  identity lag {
    base eth-inf-type;
    description
      "Identity of LAG Interface type";
  }

  identity bw-type {
    description
      "Identity of bandwidth";
  }

  identity bw-per-cos {
    base bw-type;
    description
      "Bandwidth is per cos";
  }

  identity bw-per-port {
    base bw-type;
    description
      "Bandwidth is per site network access";
  }

  identity bw-per-site {
    base bw-type;
    description
      "Bandwidth is per site. It is applicable to
       all the site network accesses within the site.";



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  }

  identity bw-per-svc {
    base bw-type;
    description
      "Bandwidth is per VPN service";
  }

  identity site-vpn-flavor {
    description
      "Base identity for the site VPN service flavor.";
  }

  identity site-vpn-flavor-single {
    base site-vpn-flavor;
    description
      "Identity for the site VPN service flavor.
       Used when the site belongs to only one VPN.";
  }

  identity site-vpn-flavor-multi {
    base site-vpn-flavor;
    description
      "Identity for the site VPN service flavor.
       Used when a logical connection of a site
       belongs to multiple VPNs.";
  }

  identity site-vpn-flavor-nni {
    base site-vpn-flavor;
    description
      "Identity for the site VPN service flavor.
       Used to describe an NNI option A connection.";
  }

  identity service-type {
    description
      "Base Identity of service type.";
  }

  identity vpws {
    base service-type;
    description
      "point-to-point Virtual Private Wire Services(VPWS) type.";
  }

  identity pwe3 {
    base service-type;



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    description
      "Pseudo-Wire Emulation Edge to
       Edge (PWE3) Service type.";
  }

  identity ldp-l2tp-vpls {
    base service-type;
    description

      "LDP based or L2TP based multipoint Virtual Private LAN
       services (VPLS) Service Type.This VPLS uses LDP-signaled
       Pseudowires or L2TP signaled Pseudowires.";
  }

  identity bgp-vpls {
    base service-type;
    description
      "BGP based multipoint Virtual Private LAN services (VPLS)
       Service Type. This VPLS uses a Border Gateway Protocol
       (BGP) control plane as described in RFC4761 and RFC6624.";
  }

  identity vpws-evpn {
    base service-type;
    description
      "VPWS Service Type using Ethernet VPN(EVPN)
      specified in RFC 7432.";
  }

  identity pbb-evpn {
    base service-type;
    description
      "PBB Service Type using Ethernet VPN(EVPN)
      specified in RFC 7432.";
  }

  identity bundling-type {
    description
      "This is base identity for Bundling type. It supports
       multiple CE-VLAN associated with L2VPN service or
       all CE-VLANs associated with L2VPN service.";
  }

  identity multi-svc-bundling {
    base bundling-type;
    description
      "Identity for multiple service bundling,i.e.,
       multiple CE-VLAN IDs can be associated with an



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       L2VPN Service at site.";
  }

  identity one2one-bundling {
    base bundling-type;
    description
      "Identity for one to one service bundling,i.e.,
       Each L2VPN can be associated with only one CE-VLAN IDs
       at site.";

  }

  identity all2one-bundling {
    base bundling-type;
    description
      "Identity for all to one bundling,i.e.,all CE-VLAN IDs
       are mapped to one L2VPN Service";
  }

  identity color-id {
    description
      "base identity of color id";
  }

  identity color-id-cvlan {
    base color-id;
    description
      "Identity of color id base on  CVLAN ";
  }

  identity cos-id {
    description
      "Identity of class of service id";
  }

  identity cos-id-pcp {
    base cos-id;
    description
      "Identity of cos id based on  PCP";
  }

  identity cos-id-dscp {
    base cos-id;
    description
      "Identity of cos id based on  DSCP";
  }

  identity color-type {



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    description
      "Identity of color types";
  }

  identity green {
    base color-type;
    description
      "Identity of green type";
  }

  identity yellow {
    base color-type;
    description
      "Identity of yellow type";
  }

  identity red {
    base color-type;
    description
      "Identity of red type";
  }

  identity policing {
    description
      "Identity of policing type";
  }

  identity one-rate-two-color {
    base policing;
    description
      "Identity of one-rate, two-color (1R2C).";
  }

  identity two-rate-three-color {
    base policing;
    description
      "Identity of two-rate, three-color (2R3C).";
  }

  identity bum-type {
    description
      "Identity of BUM type.";
  }

  identity broadcast {
    base bum-type;
    description
      "Identity of broadcast.";



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  }

  identity unicast {
    base bum-type;
    description
      "Identity of unicast";
  }

  identity multicast {
    base bum-type;

    description
      "Identity of multicast.";
  }

  identity loop-prevention-type {
    description
      "Identity of loop prevention.";
  }

  identity shut {
    base loop-prevention-type;
    description
      "Identity of shut protection.";
  }

  identity trap {
    base loop-prevention-type;
    description
      "Identity of trap protection.";
  }

  identity lacp-state {
    description
      "Identity of LACP state.";
  }

  identity lacp-on {
    base lacp-state;
    description
      "Identity of LCAP on.";
  }

  identity lacp-off {
    base lacp-state;
    description
      "Identity of LACP off";
  }



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  identity lacp-mode {
    description
      "Identity of LACP mode";
  }

  identity lacp-passive {
    base lacp-mode;
    description
      "Identity of LACP passive";
  }

  identity lacp-active {
    base lacp-mode;
    description
      "Identity of LACP active";
  }

  identity lacp-speed {
    description
      "Identity of LACP speed";
  }

  identity lacp-fast {
    base lacp-speed;
    description
      "Identity of LACP fast";
  }

  identity lacp-slow {
    base lacp-speed;
    description
      "Identity of LACP slow";
  }

  identity bw-direction {
    description
      "Identity for bandwidth direction";
  }

  identity input-bw {
    base bw-direction;
    description
      "Identity for input bandwidth";
  }

  identity output-bw {
    base bw-direction;
    description



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      "Identity for output bandwidth";
  }

  identity management {
    description
      "Base identity for site management scheme.";
  }

  identity co-managed {
    base management;
    description

      "Identity for co-managed site.";
  }

  identity customer-managed {
    base management;
    description
      "Identity for customer managed site.";
  }

  identity provider-managed {
    base management;
    description
      "Identity for provider managed site.";
  }

  identity address-family {
    description
      "Identity for an address family.";
  }

  identity ipv4 {
    base address-family;
    description
      "Identity for IPv4 address family.";
  }

  identity ipv6 {
    base address-family;
    description
      "Identity for IPv6 address family.";
  }

  identity vpn-topology {
    description
      "Base identity for VPN topology.";
  }



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  identity any-to-any {
    base vpn-topology;
    description
      "Identity for any to any VPN topology.";
  }

  identity hub-spoke {
    base vpn-topology;
    description
      "Identity for Hub'n'Spoke VPN topology.";
  }

  identity hub-spoke-disjoint {
    base vpn-topology;
    description
      "Identity for Hub'n'Spoke VPN topology
       where Hubs cannot talk between each other.";
  }

  identity site-role {
    description
      "Base identity for site type.";
  }

  identity any-to-any-role {
    base site-role;
    description
      "Site in an any to any L2VPN.";
  }

  identity spoke-role {
    base site-role;
    description
      "Spoke Site in a Hub-and-Spoke L2VPN.";
  }

  identity hub-role {
    base site-role;
    description
      "Hub Site in a Hub-and-Spoke L2VPN.";
  }

  identity pm-type {
    description
      "Performance monitor type";
  }

  identity loss {



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    base pm-type;
    description
      "Loss measurement";
  }

  identity delay {
    base pm-type;
    description
      "Delay measurement";
  }

  identity fault-alarm-defect-type {

    description
      "Indicating the alarm priority defect";
  }

  identity remote-rdi {
    base fault-alarm-defect-type;
    description
      "Indicates the aggregate health
       of the remote MEPs.";
  }

  identity remote-mac-error {
    base fault-alarm-defect-type;
    description
      "Indicates that one or more of the remote MEPs is
       reporting a failure in its Port Status TLV or
       Interface Status TLV.";
  }

  identity remote-invalid-ccm {
    base fault-alarm-defect-type;
    description
      "Indicates that at least one of the Remote MEP
       state machines is not receiving valid CCMs
       from its remote MEP.";
  }

  identity invalid-ccm {
    base fault-alarm-defect-type;
    description
      "Indicates that one or more invalid CCMs has been
       received and that 3.5 times that CCMs transmission
       interval has not yet expired.";
  }




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  identity cross-connect-ccm {
    base fault-alarm-defect-type;
    description
      "Indicates that one or more cross connect CCMs has been
       received and that 3.5 times of at least one of those
       CCMs transmission interval has not yet expired.";
  }

  identity frame-delivery-mode {
    description
      "Delivery types";
  }

  identity discard {
    base frame-delivery-mode;
    description
      "Service Frames are discarded.";
  }

  identity unconditional {
    base frame-delivery-mode;
    description
      "Service Frames are unconditionally
       delivered to the destination.";
  }

  identity unknown-discard {
    base frame-delivery-mode;
    description
      "Service Frame are conditionally
       delivered to the destination site and
       the packet with unknown destination address
       will be discarded.";
  }

  identity placement-diversity {
    description
      "Base identity for site placement
       constraints.";
  }

  identity bearer-diverse {
    base placement-diversity;
    description
      "Identity for bearer diversity.
       The bearers should not use common elements.";
  }




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  identity pe-diverse {
    base placement-diversity;
    description
      "Identity for PE diversity";
  }

  identity pop-diverse {
    base placement-diversity;
    description
      "Identity for POP diversity";
  }

  identity linecard-diverse {
    base placement-diversity;
    description
      "Identity for linecard diversity";
  }

  identity same-pe {
    base placement-diversity;
    description
      "Identity for having sites connected
       on the same PE";
  }

  identity same-bearer {
    base placement-diversity;
    description
      "Identity for having sites connected
       using the same bearer";
  }

  identity tagged-inf-type {
    description
      "Identity for the tagged
       interface type.";
  }

  identity priority-tagged {
    base tagged-inf-type;
    description
      "This identity the priority-tagged interface.";
  }

  identity qinq {
    base tagged-inf-type;
    description
      "Identity for the qinq tagged interface.";



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  }

  identity dot1q {
    base tagged-inf-type;
    description
      "Identity for dot1q vlan tagged interface.";
  }

  identity qinany {
    base tagged-inf-type;
    description
      "Identity for qinany tagged inteface.";
  }

  identity vxlan {
    base tagged-inf-type;
    description
      "Identity for vxlan tagged inteface.";
  }

  identity provision-model {
    description
      "base identity for provision model.";
  }

  identity single-side-provision {
    description
      "Identity for single side provisioning with discovery.";
  }

  identity doubled-side-provision {
    description
      "Identity for double side provisioning.";
  }

  identity mac-learning-mode {
    description
      "MAC learning mode";
  }

  identity data-plane {
    base mac-learning-mode;
    description
      "User MAC addresses are learned through ARP broadcast.";
  }

  identity control-plane {
    base mac-learning-mode;



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    description
      "User MAC addresses are advertised through EVPN-BGP";
  }

  identity vpn-policy-filter-type {
    description
      "Base identity for filter type.";
  }

  identity lan {
    base vpn-policy-filter-type;
    description
      "Identity for lan tag filter type.";
  }

  identity mac-action {
    description
      "Base identity for MAC action.";
  }

  identity drop {
    base mac-action;
    description
      "Identity for packet drop.";
  }

  identity flood {
    base mac-action;
    description
      "Identity for packet flooding.";
  }

  identity warning {
    base mac-action;
    description
      "Identity for sending a warning log message.";
  }

  identity qos-profile-direction {
    description
      "Base identity for qos profile direction.";
  }

  identity site-to-wan {
    base qos-profile-direction;
    description
      "Identity for Site to WAN direction.";
  }



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  identity wan-to-site {
    base qos-profile-direction;
    description
      "Identity for WAN to Site direction.";
  }

  identity bidirectional {
    base qos-profile-direction;
    description
      "Identity for both WAN to Site direction
       and Site to WAN direction.";
  }

  identity vxlan-peer-mode {
    description
      "Base identity for vxlan peer mode.";
  }

  identity static-mode {
    base vxlan-peer-mode;
    description
      "Identity for the vxlan access in static mode.";
  }

  identity bgp-mode {
    base vxlan-peer-mode;
    description
      "Identity for the vxlan access by bgp evpn learning.";
  }

  identity customer-application {
    description
      "Base identity for customer application.";
  }

  identity web {
    base customer-application;
    description
      "Identity for Web application (e.g., HTTP, HTTPS).";
  }

  identity mail {
    base customer-application;
    description
      "Identity for mail application.";
  }

  identity file-transfer {



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    base customer-application;
    description
      "Identity for file transfer application
      (e.g., FTP, SFTP).";
  }

  identity database {
    base customer-application;
    description
      "Identity for database application.";
  }

  identity social {
    base customer-application;
    description
      "Identity for social-network application.";
  }

  identity games {
    base customer-application;
    description
      "Identity for gaming application.";
  }

  identity p2p {
    base customer-application;
    description
      "Identity for peer-to-peer application.";
  }

  identity network-management {
    base customer-application;
    description
      "Identity for management application
       (e.g., Telnet, syslog, SNMP).";

  }

  identity voice {
    base customer-application;
    description
      "Identity for voice application.";
  }

  identity video {
    base customer-application;
    description
      "Identity for video conference application.";



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  }

  identity embb {
    base customer-application;
    description
      "Identity for enhanced Mobile Broadband(eMBB)
       application. Note that eMBB application demands
       the network performance with wide variety of
       characteristics such as data rate, latency,
       loss rate, reliability and many other parameters.";
  }

  identity urllc {
    base customer-application;
    description
      "Identity for Ultra-Reliable and Low Latency
       Communications (URLLC) application. Note that
       URLLC application demands the network performance
       with wide variety of characteristics such as latency,
       reliability and many other parameters.";
  }

  identity mmtc {
    base customer-application;
    description
      "Identity for massive Machine Type
       Communications (mMTC) application. Note that
       mMTC application demands the network performance
       with wide variety of characteristics such as data
       rate, latency, loss rate, reliability and many
       other parameters.";
  }

  grouping site-acl {
    container access-control-list {
      if-feature acl;
      list mac {
        key "mac-address";
        leaf mac-address {
          type yang:mac-address;
          description
            "MAC address.";
        }
        description
          "List for MAC.";
      }
      description
        "Container for access control List.";



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    }
    description
      "This grouping defines Access Control List.";
  }

  grouping site-bum {
    container broadcast-unknown-unicast-multicast {
      if-feature bum;
      leaf multicast-site-type {
        type enumeration {
          enum "receiver-only" {
            description
              "The site only has receivers.";
          }
          enum "source-only" {
            description
              "The site only has sources.";
          }
          enum "source-receiver" {
            description
              "The site has both sources and receivers.";
          }
        }

        default "source-receiver";
        description
          "Type of multicast site.";
      }
      list multicast-gp-address-mapping {
        key "id";
        leaf id {
          type uint16;
          description
            "Unique identifier for the mapping.";
        }
        leaf vlan-id {
          type uint16 {
            range "0..1024";
          }
          mandatory true;
          description
            "The VLAN ID of the Multicast group.
             The range of 12 bit VLAN ID is 0 to 1024.";
        }
        leaf mac-gp-address {
          type yang:mac-address;
          mandatory true;
          description



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            "the MAC address of the Multicast group.";
        }
        leaf port-lag-number {
          type uint32;
          description
            "the ports/LAGs belonging to the Multicast group.";
        }
        description
          "List of Port to group mappings.";
      }
      leaf bum-overall-rate {
        type uint64;
        units "bps";
        description
          "overall rate for BUM.";
      }
      list bum-rate-per-type {
        key "type";
        leaf type {
          type identityref {
            base bum-type;
          }
          description
            "BUM type.";
        }
        leaf rate {
          type uint64;
          units "bps";
          description
            "rate for BUM.";
        }
        description
          "List of rate per type.";
      }
      description
        "Container of broadcast, unknown unicast, and multicast
         configurations.";
    }
    description
      "Grouping for broadcast, unknown unicast, and multicast.";
  }

  grouping site-mac-loop-prevention {
    container mac-loop-prevention {
      if-feature mac-loop-prevention;
      leaf protection-type {
        type identityref {
          base loop-prevention-type;



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        }
        default "trap";
        description
          "Protection type. By default, the protection
           type is trap protection type.";
      }
      leaf frequency {
        type uint32;
        default "5";
        description
          "The number of times to detect MAC duplication.
           When duplicate-MAC situation has occurred and the
           duplicated MAC is added into to a duplicate-MAC
           list. By default, the number of times is 5.";
      }
      leaf retry-timer {
        type uint32;
        units "seconds";
        description
          "The retry timer. When retry timer expires,
           the duplicated MAC will be flushed from
           the MAC-VRF. ";
      }
      description
        "Container of MAC loop prevention.";
    }
    description
      "Grouping for MAC loop prevention.";
  }

  grouping site-service-qos-profile {
    container qos {
      if-feature qos;
      container classification-policy {
        list rule {
          key "id";
          ordered-by user;
          leaf id {
            type string;
            description
              "A description identifying qos classification
               policy rule.";
          }
          choice match-type {
            default "match-flow";
            case match-flow {
    container match-flow {
      leaf dscp {



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        type inet:dscp;
        description
          "DSCP value.";
      }
      leaf dot1q {
        type uint16;

        description
          "802.1q matching. It is VLAN Tag added into frame.";
      }
      leaf pcp {
        type uint8 {
          range "0 .. 7";
        }
        description
          "PCP value.";
      }
      leaf src-mac {
        type yang:mac-address;
        description
          "Source MAC";
      }
      leaf dst-mac {
        type yang:mac-address;
        description
          "Destination MAC.";
      }
      leaf color-type {
        type identityref {
          base color-type;
        }
        description
          "Color Types.";
      }
      leaf-list target-sites {
        if-feature target-sites;
        type svc-id;
        description
          "Identify a site as traffic destination.";
      }
      leaf any {
        type empty;
        description
          "Allow all.";
      }
      leaf vpn-id {
        type svc-id;
        description



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          "Reference to the target VPN.";
      }
      description
        "Describe flow matching criteria.";
    }
            }
            case match-application {
              leaf match-application {
                type identityref {
                  base customer-application;
                }
                description
                  "Defines the application to match.";
              }
            }
            description
              "Choice for classification";
          }
          leaf target-class-id {
            type string;
            description
              "Identification of the class of service.
               This identifier is internal to the
               administration.";
          }
          description
            "List of marking rules.";
        }
        description
          "Configuration of the traffic classification policy.";
      }
      container qos-profile {
        choice qos-profile {
          description
            "Choice for QoS profile.
             Can be standard profile or customized profile.";
          case standard {
            description
              "Standard QoS profile.";
            leaf profile {
              type leafref {
                path "/l2vpn-svc/vpn-profiles/"
                 +"valid-provider-identifiers"
                  +"/qos-profile-identifier";
              }
              description
                "QoS Profile to be used.";
            }



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          }
          case custom {
            description
              "Customized QoS profile.";
            container classes {
              if-feature qos-custom;
              list class {
                key "class-id";
                leaf class-id {
                  type string;
                  description
                    "Identification of the class of
                     service. This identifier is internal
                     to the administration.";
                }
                leaf direction {
                  type identityref {
                    base qos-profile-direction;
                  }
                  default "bidirectional";
                  description
                    "The direction which QoS profile is applied to.
                     By default,the direction is bidirectional.";
                }
                leaf policing {
                  type identityref {
                    base policing;
                  }
                  default "one-rate-two-color";
                  description
                    "The policing can be either one-rate,
                     two-color (1R2C) or two-rate, three-color
                     (2R3C). By default, the policing is on rate
                     two color.";

                }
                leaf byte-offset {
                  type uint16;
                  description
                    "For not including extra VLAN tags in the QoS
                     calculation.";
                }
                container frame-delay {
                  choice flavor {
                    case lowest {
                      leaf use-lowest-latency {
                        type empty;
                        description



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                          "The traffic class should use
                           the lowest delay path.";
                      }
                    }
                    case boundary {
                      leaf delay-bound {
                        type uint16;
                        units "msec";
                        description
                          "The traffic class should use
                           a path with a defined maximum
                           delay.";
                      }
                    }
                    description
                      "Delay constraint on the traffic
                       class.";
                  }
                  description
                    "Delay constraint on the traffic
                     class.";
                }
                container frame-jitter {
                  choice flavor {
                    case lowest {
                      leaf use-lowest-jitter {
                        type empty;
                        description
                          "The traffic class should use
                           the lowest jitter path.";
                      }
                    }
                    case boundary {
                      leaf delay-bound {
                        type uint32;

                        units "usec";
                        description
                          "The traffic class should use
                           a path with a defined maximum
                           jitter.";
                      }
                    }
                    description
                      "Jitter constraint on the traffic
                       class.";
                  }
                  description



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                    "Jitter constraint on the traffic
                     class.";
                }
                container frame-loss {
                  leaf rate {
                    type decimal64 {
                      fraction-digits 2;
                      range "0..100";
                    }
                    units "percent";
                    description
                      "Frame Loss rate constraint on the traffic
                      class.";
                  }
                  description
                    "Container for frame loss rate.";
                }
                container bandwidth {
                  leaf guaranteed-bw-percent {
                    type decimal64 {
                      fraction-digits 5;
                      range "0..100";
                    }
                    units "percent";
                    mandatory true;
                    description
                      "To be used to define the guaranteed bandwidth
                       as a percentage of the available service
                       bandwidth.";
                  }
                  leaf end-to-end {
                    type empty;
                    description
                      "Used if the bandwidth reservation
                       must be done on the MPLS network too.";
                  }
                  description
                    "Bandwidth constraint on the traffic class.";
                }
                description
                  "List of class of services.";
              }
              description
                "Container for list of class of services.";
            }
          }
        }
        description



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          "Qos profile configuration.";
      }
      description
        "QoS configuration.";
    }
    description
      "This grouping defines QoS parameters
       for a site";
  }

  grouping site-service-mpls {
    container carrierscarrier {
      if-feature carrierscarrier;
      leaf signaling-type {
        type identityref {
          base carrierscarrier-type;
        }
        default "bgp";
        description
          "Carrierscarrier. By default,the signaling type is bgp.";
      }
      description
        "Container for carrierscarrier";
    }
    description
      "Grouping for carrierscarrier";
  }

  container l2vpn-svc {
    container vpn-profiles {
    container valid-provider-identifiers {
      leaf-list cloud-identifier {
        if-feature cloud-access;
          type string;
          description
            "Identification of public cloud service
             or internet service. Local administration
             meaning.";
      }
      leaf-list qos-profile-identifier {
          type string;
          description
            "Identification of the QoS Profile to be used.
             Local administration meaning.";
      }
      leaf-list bfd-profile-identifier {
          type string;
          description



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            "Identification of the SP BFD Profile to be used.
             Local administration meaning.";
      }
      leaf-list remote-carrier-identifier {
          type string;
          description
            "Identification of the remote carrier name to be used.
             It can be L2VPN partner, Data center service provider
             or private cloud service provider. Local administration
             meaning.";
      }
      nacm:default-deny-write;
      description
        "Container for Valid Provider Identifies.";
    }
      description
        "Container for VPN Profiles.";
    }
    container vpn-services {
      list vpn-service {
        key "vpn-id";
        leaf vpn-id {
          type svc-id;
          description
            "Defining a service id.";

        }
        leaf vpn-svc-type {
          type identityref {
            base service-type;
          }
          default "vpws";
          description
            "Service type. By default, the service type is VPWS.";
        }
        leaf customer-name {
          type string;
          description
            "Customer name.";
        }
        leaf svc-topo {
          type identityref {
            base vpn-topology;
          }
          default "any-to-any";
          description
            "Defining service topology, such as
             any-to-any,hub-spoke, etc.";



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        }
    container cloud-accesses {
      if-feature cloud-access;

      list cloud-access {
        key "cloud-identifier";
        leaf cloud-identifier {
          type leafref {
            path "/l2vpn-svc/vpn-profiles/valid-provider-identifiers"
              +"/cloud-identifier";
          }
          description
            "Identification of cloud service.
             Local administration meaning.";
        }
        choice list-flavor {
          case permit-any {
            leaf permit-any {
              type empty;
              description
                "Allow all sites.";
            }
          }
          case deny-any-except {
            leaf-list permit-site {
              type leafref {
                path "/l2vpn-svc/sites/site/site-id";
              }
              description
                "Site ID to be authorized.";
            }
          }
          case permit-any-except {
            leaf-list deny-site {
              type leafref {
                path "/l2vpn-svc/sites/site/site-id";
              }
              description
                "Site ID to be denied.";
            }
          }
          description
            "Choice for cloud access policy.
             By default, all sites in the L2VPN
             MUST be authorized to access the cloud.";
        }
        description
          "Cloud access configuration.";



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      }
      description
        "Container for cloud access configurations";
    }
    container frame-delivery {
      if-feature bum;
      container customer-tree-flavors {
        leaf-list tree-flavor {
          type identityref {
            base multicast-tree-type;
          }
          description
            "Type of tree to be used.";
        }
        description
          "Type of trees used by customer.";
      }
    container bum-deliveries {
      list bum-delivery {
        key "frame-type";

        leaf frame-type {
          type identityref {
            base tf-type;
          }
          description
            "Type of frame delivery. It support unicast
             frame delivery, multicast frame delivery
              and broadcast frame delivery.";
        }
        leaf delivery-mode {
          type identityref {
            base frame-delivery-mode;
          }
          default "unconditional";
          description
            "Define Frame Delivery Mode
             (unconditional[default],
            conditional, or discard).
            By default, Service Frames
            are unconditionally delivered
            to the destination. ";
        }
        description
          "List of frame delivery type and mode.";
      }
      description
        "Define frame delivery type and mode.";



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    }
      leaf multicast-gp-port-mapping {
        type identityref {
          base mapping-type;
        }
        mandatory true;
        description
          "Describe the way in which each interface is
           associated with the Multicast group";
      }
      description
        "Multicast global parameters for the VPN service.";
    }
    container extranet-vpns {
      if-feature extranet-vpn;
      list extranet-vpn {
        key "vpn-id";
        leaf vpn-id {
          type svc-id;
          description
            "Identifies the target VPN the local VPN want to access.";
        }
        leaf local-sites-role {
          type identityref {
            base site-role;
          }
          default "any-to-any-role";
          description
            "This describes the role of the local sites in the target
             VPN topology. In the any-to-any VPN service topology,
             the local sites must have the same role, which will be
             'any-to-any-role '. In the Hub-and-Spoke VPN service
             topology or the Hub and Spoke disjoint VPN service
             topology, the local sites must have a Hub role or a
              Spoke role";
        }
        description
          "List of extranet VPNs the local VPN is attached to.";
      }
      description
        "Container for extranet VPN configuration.";
    }
    leaf ce-vlan-preservation {
      type boolean;
      mandatory true;
      description
        "Preserve the CE-VLAN ID from ingress to egress,i.e.,
         CE-VLAN tag of the egress frame are identical to



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         those of the ingress frame that yielded this
         egress service frame. If All-to-One bundling within
         a site is Enabled, then preservation applies to all
         Ingress service frames. If All-to-One bundling is
         Disabled , then preservation applies to tagged
         Ingress service frames having CE-VLAN ID 1
         through 4094.";
    }
    leaf ce-vlan-cos-perservation {
      type boolean;
      mandatory true;
      description
        "CE vlan CoS preservation. PCP bits in the CE-VLAN tag
         of the egress frame are identical to those of the
         ingress frame that yielded this egress service
         frame.";
    }
        leaf carrierscarrier {
          if-feature carrierscarrier;
          type boolean;
          default "false";
          description
            "The VPN is using CsC, and so MPLS
             is required.";
        }
        description
          "List of vpn services.";
      }
      description
        "Container for VPN services.";
    }
    container sites {
      list site {
        key "site-id";
        leaf site-id {
          type string;
          description
            "Identifier of the site.";
        }
    leaf site-vpn-flavor {
      type identityref {
        base site-vpn-flavor;
      }
      default "site-vpn-flavor-single";
      description
        "Defines the way the VPN multiplexing is
         done ,e.g.,whether the site belongs to
         a single VPN site or a multiVPN; By



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         default, the site belongs to a single VPN.";
    }
    container devices {
      when "derived-from-or-self(../management/type, "
        +"'l2vpn-svc:provider-managed') or "
        +"derived-from-or-self(../management/type, "
        +"'l2vpn-svc:co-managed')" {
        description
          "Applicable only for provider-managed or
           co-managed device.";
      }
      list device {
        key "device-id";
        leaf device-id {
          type string;
          description
            "Identifier for the device.";
        }
        leaf location {
          type leafref {
            path "../../../locations/location/location-id";
          }
          mandatory true;
          description
            "Location of the device.";
        }
        container management {
          when "derived-from-or-self(../../../management/type,"
            +"'l2vpn-svc:co-managed')" {

            description
              "Applicable only for co-managed device.";
          }
          leaf transport {
            type identityref {
              base address-family;
            }
            description
              "Transport protocol or Address family
               used for management.";
          }
          leaf address {
            when "(../ transport)" {
              description
                "If address-family is specified, then address should
                 also be specified. If the transport is not specified,
                 then address should also not be specified.";
            }



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            type inet:ip-address;
            description
              "Management address.";
          }
          description
            "Management configuration. Applicable only for
              co-managed device.";
        }
        description
          "List of devices requested by customer.";
      }
      description
        "Devices configuration";
    }
    container management {
      leaf type {
        type identityref {
          base management;
        }
        mandatory true;
        description
          "Management type of the connection.";
      }
      description

        "Management configuration.";
    }
    container locations {
      list location {
        key "location-id";
        leaf location-id {
          type string;
          description
            "Location ID";
        }
        leaf address {
          type string;
          description
            "Address (number and street) of the site.";
        }
        leaf postal-code {
          type string;
          description
            "postal code of the site. The format of postal-code is
             similar to postal code label format defined in
             RFC4119.";
        }
        leaf state {



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          type string;
          description
            "State of the site. This leaf can also be used to
             describe a region for country who does not have
             states.";
        }
        leaf city {
          type string;
          description
            "City of the site.";
        }
        leaf country-code {
          type string;
          description
            "Country of the site. The format of country-code is similar
             to country label defined in RFC4119.";
        }
        description
          "List for location";
      }
      description
        "Location of the site.";
    }

    container site-diversity {
      if-feature site-diversity;
      container groups {
        list group {
          key "group-id";
          leaf group-id {
            type string;
            description
              "Group-id the site is belonging to";
          }
          description
            "List of group-id";
        }
        description
          "Groups the site is belonging to.
           All site network accesses will inherit those group
           values.";
      }
      description
        "Diversity constraint type.";
    }

    container vpn-policies {
      list vpn-policy {



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        key "vpn-policy-id";
        leaf vpn-policy-id {
          type string;
          description
            "Unique identifier for the VPN policy.";
        }
        list entries {
          key "id";
          leaf id {
            type string;
            description
              "Unique identifier for the policy entry.";
          }
          container filters {
            list filter {
              key "type";
              ordered-by user;
              leaf type {
                type identityref {
                  base vpn-policy-filter-type;
                }
                description
                  "Type of VPN Policy filter.";
              }
              leaf-list lan-tag {
                when "derived-from-or-self(../type, 'l2vpn-svc:lan')" {
                  description
                    "Only applies when VPN Policy filter is
                     LAN Tag filter.";
                }
                if-feature lan-tag;
                type uint32;
                description
                  "List of Ethernet LAN Tag to be matched. Ethernet
                   LAN Tag identifies a particular broadcast domain
                   in a VPN. ";
              }
              description
                "List of filters used on the site. This list can
                 be augmented.";
            }
            description
              "If a more-granular VPN attachment is necessary,
               filtering can be used. If used, it permits the
               splitting of site LANs among multiple VPNs. The
               Site LAN can be split based on either LAN-tag or
               LAN prefix. If no filter is used, all the LANs
               will be part of the same VPNs with the same



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               role.";
          }
          list vpn {
            key "vpn-id";
            leaf vpn-id {
              type leafref {
                path "/l2vpn-svc/vpn-services/vpn-service/vpn-id";
              }
              description
                "Reference to L2VPN.";
            }
            leaf site-role {
              type identityref {
                base site-role;
              }
              default "any-to-any-role";
              description
                "Role of the site in the L2VPN.";
            }
            description
              "List of VPNs the LAN is associated with.";
          }
          description
            "List of entries for export policy.";
        }
        description
          "List of VPN policies.";
      }
      description
        "VPN policy.";
    }
    container service {
      uses site-service-qos-profile;
      uses site-service-mpls;
      description
        "Service parameters on the attachment.";
    }
        uses site-bum;
        uses site-mac-loop-prevention;
        uses site-acl;
    leaf actual-site-start {
      type yang:date-and-time;
      config false;
      description
        "Optional leaf indicating actual date
         and time when the service at a particular
         site actually started";
    }



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    leaf actual-site-stop {
      type yang:date-and-time;
      config false;
      description
        "Optional leaf indicating actual date
         and time when the service at a particular
         site actually stopped";
    }
    leaf bundling-type {
      type identityref {
        base bundling-type;
      }
      default "one2one-bundling";
      description
        "Bundling type. By default, Each L2VPN
         can be associated with only one
         CE-VLAN ,i.e., one to one bundling is used.";
    }
    leaf default-ce-vlan-id {
      type uint32;
      mandatory true;
      description
        "Default CE VLAN ID set at site level.";
    }
        container site-network-accesses {
          list site-network-access {
            key "network-access-id";
            leaf network-access-id {
              type string;
              description
                "Identifier of network access";
            }
            leaf remote-carrier-name {
              when "derived-from-or-self(../../../site-vpn-flavor,"+
                "'l2vpn-svc:site-vpn-flavor-nni')" {
                description
                  "Relevant when Site vpn flavor is
                  site-vpn-flavor-nni.";
              }
              type leafref {
                path "/l2vpn-svc/vpn-profiles/"+
                 "valid-provider-identifiers"+
                  "/remote-carrier-identifier";
              }
              description
                "Remote carrier name. The remote-carrier-name
                 must be configured only when site-vpn-flavor
                 is set to site vpn-flavor-nni. If it is not



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                 set,it indicates customer does not know remote
                 carrier name beforehand.";
            }
    leaf type {
      type identityref {
        base site-network-access-type;
      }
      default "point-to-point";
      description
        "Describes the type of connection, e.g.,
         point-to-point or multipoint.";
    }
    choice location-flavor {
      case location {
        when "derived-from-or-self(../../management/type, "
          +"'l2vpn-svc:customer-managed')" {
          description
            "Applicable only for customer-managed device.";
        }
        leaf location-reference {
          type leafref {
            path "../../../locations/location/location-id";
          }
          description
            "Location of the site-network-access.";
        }
      }
      case device {
        when "derived-from-or-self(../../management/type, "
          +"'l2vpn-svc:provider-managed') or "
          +"derived-from-or-self(../../management/type, "
          +"'l2vpn-svc:co-managed')" {
          description
            "Applicable only for provider-managed
             or co-managed device.";
        }
        leaf device-reference {
          type leafref {
            path "../../../devices/device/device-id";
          }
          description
            "Identifier of CE to use.";
        }
      }
      mandatory true;
      description
        "Choice of how to describe the site's location.";
    }



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    container access-diversity {
      if-feature site-diversity;
    container groups {
      list group {
        key "group-id";
        leaf group-id {
          type string;
          description
            "Group-id the site is belonging to.";
        }
        description
          "List of group-id";
      }
      description
        "Groups the site or site-network-access
         is belonging to.";
    }
      container constraints {
        list constraint {
          key "constraint-type";
          leaf constraint-type {
            type identityref {
              base placement-diversity;
            }
            description
              "Diversity constraint type.";
          }
          container target {
            choice target-flavor {
              default "id";
              case id {
                list group {
                  key "group-id";
                  leaf group-id {
                    type string;
                    description
                      "The constraint will apply
                       against this particular
                       group-id.";
                  }
                  description
                    "List of groups.";
                }
              }
              case all-accesses {
                leaf all-other-accesses {
                  type empty;
                  description



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                    "The constraint will apply
                     against all other site network
                     access of this site.";
                }
              }
              case all-groups {

                leaf all-other-groups {
                  type empty;
                  description
                    "The constraint will apply
                     against all other groups the
                     customer is managing.";
                }
              }
              description
                "Choice for the group definition.";
            }
            description
              "The constraint will apply against
               this list of groups.";
          }
          description
            "List of constraints.";
        }
        description
          "Constraints for placing this site
           network access.";
      }
      description
        "Diversity parameters.";
    }
    container bearer {
      container requested-type {
        if-feature requested-type;
        leaf type {
          type string;
          description
            "Type of requested bearer Ethernet, ATM, Frame
             Relay, IP Layer 2 Transport, Frame Relay DLCI,
             SONET/SDH,PPP.";
        }
        leaf strict {
          type boolean;
          default "false";
          description
            "Define if the requested-type is a preference
             or a strict requirement.";



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        }
        description
          "Container for requested type.";
      }
      leaf always-on {
        if-feature always-on;
        type boolean;
        default "true";
        description
          "Request for an always on access type.
           For example.This could mean no Dial access type.";
      }
      leaf bearer-reference {
        if-feature bearer-reference;
        type string;
        description
          "This is an internal reference for the
           service provider.";
      }
      description
        "Bearer specific parameters.
         To be augmented.";
    }
    container connection {
      leaf encapsulation-type {
        type identityref {
          base encapsulation-type;
        }
        default "ethernet";
        description
          "Encapsulation Type. By default,the
           encapsulation type is set as Ethernet.";
      }
      leaf eth-inf-type {
        type identityref {
          base eth-inf-type;
        }
        default "untagged";
        description
          "Ethernet Interface Type. By default,
          the Ethernet Interface Type is set as
          untagged interface.";
      }
    container tagged-interface {
      leaf type {
        type identityref {
          base tagged-inf-type;
        }



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        default "priority-tagged";
        description
          "Tagged interface type. By default,
           the Tagged interface type is priority
           tagged interface. ";
      }
      container dot1q-vlan-tagged {
        when "derived-from-or-self(../type, 'l2vpn-svc:dot1q')" {
          description
            "Only applies when Tagged interface type is dot1q.";
        }
        if-feature dot1q;
        leaf tg-type {
          type identityref {
            base tag-type;
          }
          default "c-vlan";
          description
            "TAG type.By default, Tag type is Customer-VLAN tag.";
        }
        leaf cvlan-id {
          type uint16;
          mandatory true;
          description
            "VLAN identifier.";
        }
        description
          "Tagged interface.";
      }
      container priority-tagged {
        when "derived-from-or-self(../type, "
          +"'l2vpn-svc:priority-tagged')" {
          description
            "Only applies when Tagged interface type
             is priority tagged interface.";
        }
        leaf tag-type {
          type identityref {
            base tag-type;
          }
          default "c-vlan";
          description
            "TAG type.By default, the TAG type is
             Customer-VLAN tag.";
        }
        description
          "Priority tagged.";
      }



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      container qinq {
        when "derived-from-or-self(../type, 'l2vpn-svc:qinq')" {
          description
            "Only applies when Tagged interface type is qinq.";
        }
        if-feature qinq;
        leaf tag-type {
          type identityref {
            base tag-type;
          }
          default "c-s-vlan";
          description
            "Tag type. By default, the Tag type is c-s-vlan.";
        }
        leaf svlan-id {
          type uint16;
          mandatory true;
          description
            "S-VLAN Identifier.";
        }
        leaf cvlan-id {
          type uint16;
          mandatory true;
          description
            "C-VLAN Identifier";
        }
        description
          "QinQ.";
      }
      container qinany {
        when "derived-from-or-self(../type, 'l2vpn-svc:qinany')" {
          description
            "Only applies when Tagged interface type is qinany.";
        }
        if-feature qinany;
        leaf tag-type {
          type identityref {
            base tag-type;
          }
          default "s-vlan";
          description
            "Tag type.By default, the Tag type is Service-VLAN tag.";
        }
        leaf svlan-id {
          type uint16;
          mandatory true;
          description
            "S-Vlan ID.";



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        }
        description
          "Container for Qin Any.";
      }
      container vxlan {
        when "derived-from-or-self(../type, 'l2vpn-svc:vxlan')" {
          description
            "Only applies when Tagged interface type is vxlan.";
        }
        if-feature vxlan;
        leaf vni-id {
          type uint32;
          mandatory true;
          description
            "VNI Identifier.";
        }
        leaf peer-mode {
          type identityref {
            base vxlan-peer-mode;
          }
          default "static-mode";
          description
            "specify the vxlan access mode. By default
             the peer mode is Set as static mode.";
        }
        list peer-list {
          key "peer-ip";
          leaf peer-ip {
            type inet:ip-address;
            description
              "Peer IP.";
          }
          description
            "List for peer IP.";
        }
        description
          "QinQ.";
      }

      description
        "Container for tagged Interface.";
    }
    container untagged-interface {
      leaf speed {
        type uint32;
        units "mbps";
        default "10";
        description



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          "Port speed.";
      }
      leaf mode {
        type neg-mode;
        default "auto-neg";
        description
          "Negotiation mode.";
      }
      leaf phy-mtu {
        type uint32;
        units "bytes";
        description
          "PHY MTU.";
      }
      leaf lldp {
        type boolean;
        default "false";
        description
          "LLDP. Indicate LLDP is supported.";
      }
      container oam-802.3ah-link {
        if-feature oam-3ah;
        leaf enable {
          type boolean;
          default "false";
          description
            "Indicate whether support oam 802.3 ah link";
        }
        description
          "Container for oam 802.3 ah link.";
      }
      leaf uni-loop-prevention {
        type boolean;
        default "false";
        description
          "If this leaf set to truth that the port automatically
           goes down when a physical loopback is detect.";
      }
      description
        "Container of Untagged Interface Attributes
         configurations.";
    }
    container lag-interfaces {
      if-feature lag-interface;
      list lag-interface {
        key "index";
        leaf index {
          type string;



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          description
            "LAG interface index.";
        }
    container lacp {
      if-feature lacp;
      leaf enable {
        type boolean;

        default "false";
        description
          "LACP on/off.By default, LACP is disabled.";
      }
      leaf mode {
        type neg-mode;
        description
          "LACP mode. LACP modes have auto negotiation mode
           and passive mode (false). Auto negotiation mode
           means initiating the auto speed negotiation and
           trying to form Ethernet Channel with other end.
           Passive mode means not initiating the negotiation,
          but responding to LACP packets initiated by other
          end(e.g., full duplex or half duplex. ";
      }
      leaf speed {
        type uint32;
        units "mbps";
        default "10";
        description
          "LACP speed. By default, the lacp speed is 10Mbps.";
      }
      leaf mini-link-num {
        type uint32;
        description
          "Defines the minimum number of links that must be
           active before the aggregating link is put
           into service.";
      }
      leaf system-priority {
        type uint16;
        default "32768";
        description
          "Indicates the LACP priority for the system.
           The range is from 0 to 65535.
           The default is 32768.";
      }
      container micro-bfd {
        if-feature micro-bfd;
        leaf enable {



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          type enumeration {
            enum "on" {
              description
                "Micro-bfd on.";
            }
            enum "off" {
              description
                "Micro-bfd off.";
            }
          }
          default "off";
          description
            "Micro BFD ON/OFF. By default,
             the micro-bfd is set to off.";
        }
        leaf interval {
          type uint32;
          units "msec";
          description
            "BFD interval.";
        }
        leaf hold-timer {
          type uint32;
          units "msec";
          description
            "BFD hold timer.";
        }
        description
          "Container of Micro-BFD configurations.";
      }
      container bfd {
        if-feature bfd;
        leaf enabled {
          type boolean;
          default "false";
          description
            "BFD activation. By default, BFD is not activated.";
        }
        choice holdtime {
          default "fixed";
          case profile {
            leaf profile-name {
              type leafref {
                path "/l2vpn-svc/vpn-profiles/"
                 +"valid-provider-identifiers"
                 +"/bfd-profile-identifier";
              }
              description



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                "Service provider well known profile.";
            }
            description
              "Service provider well known profile.";
          }
          case fixed {
            leaf fixed-value {
              type uint32;

              units "msec";
              description
                "Expected hold time expressed in msec.";
            }
          }
          description
            "Choice for hold time flavor.";
        }
        description
          "Container for BFD.";
      }
      container member-links {
        list member-link {
          key "name";
          leaf name {
            type string;
            description
              "Member link name.";
          }
          leaf speed {
            type uint32;
            units "mbps";
            default "10";
            description
              "Port speed.";
          }
          leaf mode {
            type neg-mode;
            default "auto-neg";
            description
              "Negotiation mode.";
          }
          leaf link-mtu {
            type uint32;
            units "bytes";
            description
              "Link MTU size.";
          }
          container oam-802.3ah-link {



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            if-feature oam-3ah;
            leaf enable {
              type boolean;
              default "false";
              description
                "Indicate whether oam 802.3 ah link is supported.";
            }
            description
              "Container for oam 802.3 ah link.";
          }
          description
            "Member link";
        }
        description
          "Container of Member link list";
      }
      leaf flow-control {
        type boolean;
        default "false";
        description
          "Flow control. Indicate whether flow control is supported.";
      }
      leaf lldp {
        type boolean;
        default "false";
        description
          "LLDP. Indicate whether lldp is supported.";
      }
      description
        "LACP.";
    }
        description
          "List of LAG interfaces.";
      }
      description
        "Container of LAG interface attributes configuration";
    }
    list cvlan-id-to-svc-map {
      key "svc-id";
      leaf svc-id {
        type leafref {
          path "/l2vpn-svc/vpn-services/vpn-service/vpn-id";
        }
        description
          "VPN Service identifier";
      }
      list cvlan-id {
        key "vid";



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        leaf vid {
          type uint16;
          description
            "CVLAN ID";

        }
        description
          "List of CVLAN-ID to SVC Map configurations";
      }
      description
        "List for cvlan-id to L2VPn Service map configurations";
    }
    container l2cp-control {
      if-feature l2cp-control;
      leaf stp-rstp-mstp {
        type control-mode;
        description
          "STP/RSTP/MSTP protocol type applicable to all Sites.";
      }
      leaf pause {
        type control-mode;
        description
          "Pause protocol type applicable to all Sites.";
      }
      leaf lacp-lamp {
        type control-mode;
        description
          "LACP/LAMP.";
      }
      leaf link-oam {
        type control-mode;
        description
          "Link OAM.";
      }
      leaf esmc {
        type control-mode;
        description
          "ESMC.";
      }
      leaf l2cp-802.1x {
        type control-mode;

        description
          "IEEE 802.x.";
      }
      leaf e-lmi {
        type control-mode;
        description



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          "E-LMI.";
      }
      leaf lldp {
        type boolean;
        description
          "LLDP protocol type applicable to all sites.";
      }
      leaf ptp-peer-delay {
        type control-mode;
        description
          "PTP peer delay.";
      }
      leaf garp-mrp {
        type control-mode;
        description
          "GARP/MRP.";
      }
      description
        "Container of L2CP control configurations";
    }
    container oam {
      if-feature ethernet-oam;
      leaf md-name {
        type string;
        mandatory true;
        description
          "Maintenance domain name.";
      }
      leaf md-level {
        type uint16 {
          range "0..255";
        }
        mandatory true;
        description
          "Maintenance domain level. The level may be
           restricted in certain protocols (e.g.,
           protocol in layer 0 to layer 7).";
      }
  list cfm-8021-ag {
    if-feature cfm;
    key "maid";

    leaf maid {
      type string;
      mandatory true;
      description
        "Identify an Maintenance Association (MA).";
    }



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    leaf mep-id {
      type uint32;
      description
        "Local Maintenance End Point (MEP) ID.
         The non-existence of this leaf means
          that no defects are to be reported.";
    }
    leaf mep-level {
      type uint32;
      description
        "Define Maintenance End Point (MEP) level.
         The non-existence of this leaf means that
         no defects are to be reported.";
    }
    leaf mep-up-down {
      type enumeration {
        enum "up" {
          description
            "MEP up.";
        }
        enum "down" {
          description
            "MEP down.";
        }
      }
      default "up";
      description
        "MEP up/down. By default, MEP up is used.
         The non-existence of this leaf means that
         no defects are to be reported.";
    }
    leaf remote-mep-id {
      type uint32;
      description
        "Remote MEP ID. The non-existence of this leaf means
         that no defects are to be reported.";
    }
    leaf cos-for-cfm-pdus {
      type uint32;
      description
        "COS for CFM PDUs. The non-existence of this leaf means
         that no defects are to be reported.";

    }
    leaf ccm-interval {
      type uint32;
      units "msec";
      default "10000";



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      description
        "Continuity Check Message(CCM) interval.
         By default, ccm-interval is 10 seconds.";
    }
    leaf ccm-holdtime {
      type uint32;
      units "msec";
      default "35000";
      description
        "CCM hold time. By default ccm hold time
         is 3.5 times of ccm interval.";
    }
    leaf alarm-priority-defect {
      type identityref {
        base fault-alarm-defect-type;
      }
      default "remote-invalid-ccm";
      description
        "The lowest priority defect that is
         allowed to generate a Fault Alarm.By default,
         fault-alarm-defect-type is set to remote-invalid-ccm.
          The non-existence of this leaf means
          that no defects are to be reported.";
    }
    leaf ccm-p-bits-pri {
      type ccm-priority-type;
      description
        "The priority parameter for CCMs transmitted by the MEP.
         The non-existence of this leaf means
         that no defects are to be reported.";
    }
     description
       "List of 802.1ag CFM attributes";
    }
    list y-1731 {
      if-feature y-1731;
      key "maid";
      leaf maid {

        type string;
        mandatory true;
        description
          "Identify an Maintenance Association (MA).";
      }
      leaf mep-id {
        type uint32;
        description
          "Local Maintenance End Point(MEP) ID.



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           The non-existence of this leaf means
           that no measurements are to be reported.";
      }
      leaf type {
        type identityref {
          base pm-type;
        }
        default "delay";
        description
          "Performance monitor types. By default, the
           performance monitoring type is set to delay.
           The non-existence of this leaf means that no
            measurements are to be reported.";
      }
      leaf remote-mep-id {
        type uint32;
        description
          "Remote MEP ID. The non-existence of this
           leaf means that no measurements are to be
           reported.";
      }
      leaf message-period {
        type uint32;
        units "msec";
        default "10000";
        description
          "Defines the interval between Y.1731
           performance monitoring messages. The message
           period is expressed in milliseconds.";
      }
      leaf measurement-interval {
        type uint32;
        units "sec";
        description
          "Specifies the measurement interval for statistics. The
           measurement interval is expressed in seconds.";
      }
      leaf cos {
        type uint32;

        description
          "Class of service. The non-existence
           of this leaf means that no measurements
           are to be reported.";
      }
      leaf loss-measurement {
        type boolean;
        default "false";



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        description
          "Whether enable loss measurement.
           By default, loss measurement is not
           enabled.";
      }
      leaf synthethic-loss-measurement {
        type boolean;
        default "false";
        description
          "Indicate whether enable synthetic loss
           measurement.By default, synthethic loss
           measurement is not enabled.";
      }
      container delay-measurement {
        leaf enable-dm {
          type boolean;
          default "false";
          description
            "Whether to enable delay measurement.
            By defaut, the delay measurement is
             not enabled.";
        }
        leaf two-way {
          type boolean;
          default "false";
          description
            "Whether delay measurement is two-way (true) of one-
             way (false). By default, one way measurement is enabled.";
        }
        description
          "Container for delay measurement.";
      }
      leaf frame-size {
        type uint32;
        units "bytes";
        description
          "Frame size. The non-existence of this leaf means
          that no measurements are to be reported.";
      }
      leaf session-type {
        type enumeration {
          enum "proactive" {
            description
              "Proactive mode.";
          }
          enum "on-demand" {
            description
              "On demand mode.";



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          }
        }
        default "on-demand";
        description
          "Session type. By default, the session type is on demand mode.
           The non-existence of this leaf means that no measurements
           are to be reported.";
      }
      description
        "List for y-1731.";
    }
      description
        "Container for Ethernet service OAM.";
    }
      description
        "Container for bearer";
    }
    container availability {
      leaf access-priority {
        type uint32;
        default "100";
        description
          "Access priority. The higher the access-priority value,
           the higher the preference of the access will be.";
      }
      choice redundancy-mode {
        case single-active {
          leaf single-active {
            type empty;
            description
              "Single active.";
          }
          description
            "Single active case.";
        }
        case all-active {

          leaf all-active {
            type empty;
            description
              "All active.";
          }
          description
            "All active case.";
        }
        description
          "Redundancy mode choice.";
      }



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      description
        "Container of availability optional configurations.";
    }
    container vpn-attachment {
      choice attachment-flavor {
        case vpn-id {
          leaf vpn-id {
            type leafref {
              path "/l2vpn-svc/vpn-services/vpn-service/vpn-id";
            }
            description
              "Reference to a L2VPN. Referencing a vpn-id provides
               an easy way to attach a particular logical access to
               a VPN. In this case, vpn-id must be configured.";
          }
          leaf site-role {
            type identityref {
              base site-role;
            }
            default "any-to-any-role";
            description
              "Role of the site in the L2VPN. When referencing a vpn-id,
               the site-role setting must be added to express the role
               of the site in the target VPN service topology.";
          }
        }
        case vpn-policy-id {
          leaf vpn-policy-id {
            type leafref {
              path "../../../../vpn-policies/vpn-policy/vpn-policy-id";
            }
            description
              "Reference to a vpn policy.";
          }
        }
        mandatory true;
        description
          "Choice for VPN attachment flavor.";
      }
      description
        "Defines VPN attachment of a site.";
    }
    container service {
     container svc-bandwidth {
      if-feature input-bw;
      list bandwidth {
        key "direction type";
        leaf direction {



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          type identityref {
            base bw-direction;
          }
          description
            "Indicate the bandwidth direction. It can be bandwidth
             download direction from the SP to the site or
             bandwidth upload direction from the site to the SP.";
        }
        leaf type {
          type identityref {
            base bw-type;
          }
          description
            "Bandwidth Type. By default, the bandwidth type is set
             as bandwidth per cos.";
        }
        leaf cos-id {
                  when "derived-from-or-self(../type, 'l2vpn-svc:bw-per-cos')" {
            description

              "Relevant when the bandwidth type is set as bandwidth
               per cos.";
          }
          type uint8;
          description
            "Identifier of Class of Service
             , indicated by DSCP or a CE-CLAN
             CoS(802.1p)value in the service frame.
            If bandwidth type is set as bandwidth
            per cos, cos-id MUST be specified.";
        }
        leaf vpn-id {
                  when "derived-from-or-self(../type, "
                    +"'l2vpn-svc:bw-per-svc')" {
            description
              "Relevant when the bandwidth type is
               set as bandwidth per VPN service.";
          }
          type svc-id;
          description
            "Identifies the target VPN. If bandwidth
             type is set as bandwidth per VPN service,
             vpn-id MUST be specified.";
        }
        leaf cir {
          type uint64;
          units "bps";
          mandatory true;



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          description
            "Committed Information Rate. The maximum number of
             bits that a port can receive or send during
             one-second over an interface.";
        }
        leaf cbs {
          type uint64;
          units "bps";
          mandatory true;
          description
            "Committed Burst Size.CBS controls the bursty nature
             of the traffic. Traffic that does not use the configured
             CIR accumulates credits until the credits reach the
             configured CBS.";
        }
        leaf eir {
          type uint64;
          units "bps";
          description
            "Excess Information Rate,i.e.,Excess frame delivery
             allowed not subject to SLA.The traffic rate can be
             limited by eir.";
        }
        leaf ebs {
          type uint64;
          units "bps";
          description
            "Excess Burst Size. The bandwidth available for burst
             traffic from the EBS is subject to the amount of
             bandwidth that is accumulated during periods when
             traffic allocated by the EIR policy is not used.";
        }
        leaf pir {
          type uint64;
          units "bps";
          description
            "Peak Information Rate, i.e., maixmum frame delivery
             allowed.It is equal to or less than sum of cir
             and eir.";
        }
        leaf pbs {
          type uint64;
          units "bps";
          description
            "Peak Burst Size. It is measured in bytes per second.";
        }
        description
          "List for bandwidth.";



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      }
      description
        "From the customer site's perspective, the service
         input/out bandwidth of the connection or download/upload
         bandwidth from the SP/site to the site/SP.";
    }
    leaf svc-mtu {
      type uint16;
      units "bytes";
      mandatory true;
      description
        "SVC MTU, it is also known as the maximum transmission unit or
         maximum frame size,When a frame is larger than the MTU, it is
         broken down, or fragmented, into smaller pieces by the network
         protocol to accommodate the MTU of the network. If CsC is
         enabled,the requested svc-mtu leaf will refer to the
         MPLS MTU and not to the link MTU. ";
    }
      uses site-service-qos-profile;
      uses site-service-mpls;
      description
        "Container for service";
    }
    uses site-bum;
    uses site-mac-loop-prevention;
    uses site-acl;
    container mac-addr-limit {
      if-feature mac-addr-limit;
      leaf limit-number {
        type uint16;
        default "2";
        description
          "maximum number of MAC addresses learned from
           the subscriber for a single service instance.
           The default allowed maximum number of MAC

           addresses is 2.";
      }
      leaf time-interval {
        type uint32;
        units "sec";
        default "300";
        description
          "The aging time of the mac address. By default,
           the aging time is set 300 seconds.";
      }
      leaf action {
        type identityref {



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          base mac-action;
        }
        default "warning";
        description
          "specify the action when the upper limit is
           exceeded: drop the packet, flood the
           packet, or simply send a warning log message. By default,
           action is set to warning.";
      }
      description
        "Container of MAC-Addr limit configurations";
    }
            description
              "List of Site Network Accesses.";
          }
          description
            "Container of port configurations.";
        }
        description
          "List of sites.";

      }
      description
        "Container of site configurations.";
    }
    description
      "Container for L2VPN service.";
  }
}
<CODE ENDS>

9.  Security Considerations

   The YANG module specified in this document defines a schema for data
   that is designed to be accessed via network management protocols such
   as NETCONF[RFC6241] or RESTCONF [RFC8040].  The lowest NETCONF layer
   is the secure transport layer, and the mandatory-to-implement secure
   transport is Secure Shell (SSH)[RFC6242] . The lowest RESTCONF layer
   is HTTPS, and the mandatory-to-implement secure transport is TLS
   [RFC5246].

   The NETCONF access control model [RFC8341] provides the means to
   restrict access for particular NETCONF or RESTCONF users to a
   preconfigured subset of all available NETCONF or RESTCONF protocol
   operations and content.

   There are a number of data nodes defined in this YANG module that are
   writable/creatable/deletable (i.e., config true, which is the



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   default).  These data nodes may be considered sensitive or vulnerable
   in some network environments.  Write operations (e.g., edit-config)
   to these data nodes without proper protection can have a negative
   effect on network operations.  These are the subtrees and data nodes
   and their sensitivity/vulnerability:

   o  /l2vpn-svc/vpn-services/vpn-service

      The entries in the list above include the whole vpn service
      configurations which the customer subscribes, and indirectly
      create or modify the PE and CE device configurations.  Unexpected
      changes to these entries could lead to the service disruption and/
      or network misbehavior.

   o  /l2vpn-svc/sites/site

      The entries in the list above include the customer site
      configurations.  As above, unexpected changes to these entries
      could lead to the service disruption and/or network misbehavior.

   Some of the readable data nodes in this YANG module may be considered
   sensitive or vulnerable in some network environments.  It is thus
   important to control read access (e.g., via get, get-config, or
   notification) to these data nodes.  These are the subtrees and data
   nodes and their sensitivity/vulnerability:

   o  /l2vpn-svc/vpn-services/vpn-service

   o  /l2vpn-svc/sites/site

   The entries in the lists above include customer-proprietary or
   confidential information, e.g., customer-name, site location, what
   service the customer subscribes.

   When a Service Provider collaborates with multiple customers, it have
   to ensure that a given customer can only view and modify his own
   service information.

   The data model defines some security parameters that can be extended
   via augmentation as part of the customer service request; those
   parameters are described in Section 5.12 and Section 5.13.

10.  IANA Considerations

   IANA is requested to assign a new URI from the IETF XML registry
   ([RFC3688]).  The following URI is suggested:





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       URI: urn:ietf:params:xml:ns:yang:ietf-l2vpn-svc
       Registrant Contact: The IESG
       XML: N/A, the requested URI is an XML namespace


   This document also requests a new YANG module name in the YANG Module
   Names registry ([RFC6020]) with the following suggestion:


       name: ietf-l2vpn-svc
       namespace: urn:ietf:params:xml:ns:yang:ietf-l2vpn-svc
       prefix: l2vpn-svc
       reference: RFC XXXX


11.  Acknowledgements

   Thanks to Qin Wu and Adrian Farrel for facilitating work on the
   initial revisions of this document.  Thanks to Zonghe Huang, Wei Deng
   and Xiaoling Song to help review this draft.

   Special thanks to Jan Lindblat for his careful review of the YANG.

   This document has drawn on the work of the L3SM Working Group
   expressed in [RFC8299].

12.  References

12.1.  Normative References

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119,
              DOI 10.17487/RFC2119, March 1997,
              <https://www.rfc-editor.org/info/rfc2119>.

   [RFC3688]  Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688,
              DOI 10.17487/RFC3688, January 2004,
              <https://www.rfc-editor.org/info/rfc3688>.

   [RFC4364]  Rosen, E. and Y. Rekhter, "BGP/MPLS IP Virtual Private
              Networks (VPNs)", RFC 4364, DOI 10.17487/RFC4364, February
              2006, <https://www.rfc-editor.org/info/rfc4364>.

   [RFC4761]  Kompella, K., Ed. and Y. Rekhter, Ed., "Virtual Private
              LAN Service (VPLS) Using BGP for Auto-Discovery and
              Signaling", RFC 4761, DOI 10.17487/RFC4761, January 2007,
              <https://www.rfc-editor.org/info/rfc4761>.




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   [RFC5246]  Dierks, T. and E. Rescorla, "The Transport Layer Security
              (TLS) Protocol Version 1.2", RFC 5246,
              DOI 10.17487/RFC5246, August 2008,
              <https://www.rfc-editor.org/info/rfc5246>.

   [RFC6020]  Bjorklund, M., Ed., "YANG - A Data Modeling Language for
              the Network Configuration Protocol (NETCONF)", RFC 6020,
              DOI 10.17487/RFC6020, October 2010,
              <https://www.rfc-editor.org/info/rfc6020>.

   [RFC6073]  Martini, L., Metz, C., Nadeau, T., Bocci, M., and M.
              Aissaoui, "Segmented Pseudowire", RFC 6073,
              DOI 10.17487/RFC6073, January 2011,
              <https://www.rfc-editor.org/info/rfc6073>.

   [RFC6074]  Rosen, E., Davie, B., Radoaca, V., and W. Luo,
              "Provisioning, Auto-Discovery, and Signaling in Layer 2
              Virtual Private Networks (L2VPNs)", RFC 6074,
              DOI 10.17487/RFC6074, January 2011,
              <https://www.rfc-editor.org/info/rfc6074>.

   [RFC6241]  Enns, R., Ed., Bjorklund, M., Ed., Schoenwaelder, J., Ed.,
              and A. Bierman, Ed., "Network Configuration Protocol
              (NETCONF)", RFC 6241, DOI 10.17487/RFC6241, June 2011,
              <https://www.rfc-editor.org/info/rfc6241>.

   [RFC6242]  Wasserman, M., "Using the NETCONF Protocol over Secure
              Shell (SSH)", RFC 6242, DOI 10.17487/RFC6242, June 2011,
              <https://www.rfc-editor.org/info/rfc6242>.

   [RFC7432]  Sajassi, A., Ed., Aggarwal, R., Bitar, N., Isaac, A.,
              Uttaro, J., Drake, J., and W. Henderickx, "BGP MPLS-Based
              Ethernet VPN", RFC 7432, DOI 10.17487/RFC7432, February
              2015, <https://www.rfc-editor.org/info/rfc7432>.

   [RFC7950]  Bjorklund, M., Ed., "The YANG 1.1 Data Modeling Language",
              RFC 7950, DOI 10.17487/RFC7950, August 2016,
              <https://www.rfc-editor.org/info/rfc7950>.

   [RFC8040]  Bierman, A., Bjorklund, M., and K. Watsen, "RESTCONF
              Protocol", RFC 8040, DOI 10.17487/RFC8040, January 2017,
              <https://www.rfc-editor.org/info/rfc8040>.

   [RFC8174]  Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
              2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
              May 2017, <https://www.rfc-editor.org/info/rfc8174>.





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   [RFC8214]  Boutros, S., Sajassi, A., Salam, S., Drake, J., and J.
              Rabadan, "Virtual Private Wire Service Support in Ethernet
              VPN", RFC 8214, DOI 10.17487/RFC8214, August 2017,
              <https://www.rfc-editor.org/info/rfc8214>.

   [RFC8341]  Bierman, A. and M. Bjorklund, "Network Configuration
              Access Control Model", STD 91, RFC 8341,
              DOI 10.17487/RFC8341, March 2018,
              <https://www.rfc-editor.org/info/rfc8341>.

   [RFC8342]  Bjorklund, M., Schoenwaelder, J., Shafer, P., Watsen, K.,
              and R. Wilton, "Network Management Datastore Architecture
              (NMDA)", RFC 8342, DOI 10.17487/RFC8342, March 2018,
              <https://www.rfc-editor.org/info/rfc8342>.

12.2.  Informative References

   [I-D.ietf-bess-evpn-yang]
              Brissette, P., Shah, H., Hussain, I., Tiruveedhula, K.,
              and J. Rabadan, "Yang Data Model for EVPN", draft-ietf-
              bess-evpn-yang-05 (work in progress), February 2018.

   [I-D.ietf-bess-l2vpn-yang]
              Shah, H., Brissette, P., Chen, I., Hussain, I., Wen, B.,
              and K. Tiruveedhula, "YANG Data Model for MPLS-based
              L2VPN", draft-ietf-bess-l2vpn-yang-08 (work in progress),
              February 2018.

   [IEEE-802-1ag]
              IEEE, "802.1ag - Connectivity Fault Management", December
              2007.

   [IEEE-802-1D]
              IEEE, "802.1D-2004 - MAC Bridges", June 2004.

   [ITU-T-Y-1731]
              ITU-T, "Recommendation Y.1731 - OAM functions and
              mechanisms for Ethernet based networks", February 2008.

   [MEF-6]    MEF Forum, "Ethernet Services Definitions - Phase 2",
              April 2008.

   [RFC4119]  Peterson, J., "A Presence-based GEOPRIV Location Object
              Format", RFC 4119, DOI 10.17487/RFC4119, December 2005,
              <https://www.rfc-editor.org/info/rfc4119>.






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   [RFC4664]  Andersson, L., Ed. and E. Rosen, Ed., "Framework for Layer
              2 Virtual Private Networks (L2VPNs)", RFC 4664,
              DOI 10.17487/RFC4664, September 2006,
              <https://www.rfc-editor.org/info/rfc4664>.

   [RFC6624]  Kompella, K., Kothari, B., and R. Cherukuri, "Layer 2
              Virtual Private Networks Using BGP for Auto-Discovery and
              Signaling", RFC 6624, DOI 10.17487/RFC6624, May 2012,
              <https://www.rfc-editor.org/info/rfc6624>.

   [RFC7130]  Bhatia, M., Ed., Chen, M., Ed., Boutros, S., Ed.,
              Binderberger, M., Ed., and J. Haas, Ed., "Bidirectional
              Forwarding Detection (BFD) on Link Aggregation Group (LAG)
              Interfaces", RFC 7130, DOI 10.17487/RFC7130, February
              2014, <https://www.rfc-editor.org/info/rfc7130>.

   [RFC7209]  Sajassi, A., Aggarwal, R., Uttaro, J., Bitar, N.,
              Henderickx, W., and A. Isaac, "Requirements for Ethernet
              VPN (EVPN)", RFC 7209, DOI 10.17487/RFC7209, May 2014,
              <https://www.rfc-editor.org/info/rfc7209>.

   [RFC7348]  Mahalingam, M., Dutt, D., Duda, K., Agarwal, P., Kreeger,
              L., Sridhar, T., Bursell, M., and C. Wright, "Virtual
              eXtensible Local Area Network (VXLAN): A Framework for
              Overlaying Virtualized Layer 2 Networks over Layer 3
              Networks", RFC 7348, DOI 10.17487/RFC7348, August 2014,
              <https://www.rfc-editor.org/info/rfc7348>.

   [RFC7436]  Shah, H., Rosen, E., Le Faucheur, F., and G. Heron, "IP-
              Only LAN Service (IPLS)", RFC 7436, DOI 10.17487/RFC7436,
              January 2015, <https://www.rfc-editor.org/info/rfc7436>.

   [RFC8199]  Bogdanovic, D., Claise, B., and C. Moberg, "YANG Module
              Classification", RFC 8199, DOI 10.17487/RFC8199, July
              2017, <https://www.rfc-editor.org/info/rfc8199>.

   [RFC8299]  Wu, Q., Ed., Litkowski, S., Tomotaki, L., and K. Ogaki,
              "YANG Data Model for L3VPN Service Delivery", RFC 8299,
              DOI 10.17487/RFC8299, January 2018,
              <https://www.rfc-editor.org/info/rfc8299>.

   [RFC8309]  Wu, Q., Liu, W., and A. Farrel, "Service Models
              Explained", RFC 8309, DOI 10.17487/RFC8309, January 2018,
              <https://www.rfc-editor.org/info/rfc8309>.

   [RFC8340]  Bjorklund, M. and L. Berger, Ed., "YANG Tree Diagrams",
              BCP 215, RFC 8340, DOI 10.17487/RFC8340, March 2018,
              <https://www.rfc-editor.org/info/rfc8340>.



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Appendix A.  Changes Log

   Changes in v-(01) include:

   o  Reference Update.

   o  Fix figure in section 3.3 and section 3.4

   o  Consider VPWS, VPLS, EVPN as basic service and view EVC related
      service as additional service.

   o  Model structure change, move two customer information related
      parameter into VPN Services container, remove 'customer-info
      'container

   o  Redefine vpn-type to cover VPWS, VPLS, EVPN service;

   o  Consolidate EVC and OVC container, make them optional since for
      some L2VPN service such as EVPN sevice, OVC, EVC are not needed.

   o  Add service and security filter under sites container and change
      "ports" into "site-network-accesses" to get consistent with L3SM
      and also make it generalized.

   o  Fixed usage examples in the l2sm model draft.

   Changes in v-(02) include:

   o  Fix figure 3 and figure 4 in section 3.4 to apply IEEE802.3 on the
      segment between C and CE and apply IEEE802.1Q on the segment
      between CE and PE.

   o  Update Signaling Option section and add L2TP support and classify
      the signaling option type into BGP-L2VPN, BGP-EVPN, LDP-PWE, L2TP-
      PW.

   o  Add Multicast Support in section 5.2.13, section 5.10.3 and move
      the text in BUM Storm Control section into section 5.10.3.

   o  Add new section 5.3.1, section 5.4, section 5.5, section 5.6,
      section 5.7, section 5.8, section 5.11to explain the usage of
      constraint parameters and service placement related parameters.

   o  Add new section 5.1 and 5.14 to allow augmentation and external ID
      References.

   o  Add new section to discuss inter-AS support and inter-provider
      support with NNI and EVC, OVC.



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   o  Update Service Section 5.10 and define four type for svc-input-
      bandwidth and svc-output-bandwidth and add guaranteed-bw-percent
      parameter and related description.

   o  Add extranet VPN support.

   o  Remove duplicated parameters from cloud access.

   o  Move L2CP control plane protocol parameters under connection.

   o  Update section 5.3.3.2 to address loop avoidance issue and divide
      section 5.3.3.2 into Physical interface section, LAG interface
      section and Addressing Section.

   o  Reference Update.

   Changes in v-(03) include:

   o  Introduce additional terminology.

   o  Modify figure 5 to get consistent with RFC8049.

   o  Add end to end Multi-segment connectivity support and site-vpn-
      flavor-e2e attribute.

   o  Add usage example to explain how to use EVC and OVC.

   o  Discuss applicability of this model to inter-provider support.

   o  Reduce redundant parameters related to encapsulation type and
      Ethernet type in the model.

   o  Clarify the relationship between guarantee-bandwidth-percent and
      CIR, EIR and PIR.

   o  Modify model structure for VPN service to make it consistent with
      the text in section 5.

   o  Remove Sub-inf parameter since it is similar to QinQ parameter.

   o  Add "direction" parameter for QoS profile.

   o  Update XML example and figure in section 5.16.

   Changes in v-(04) include:

   o  Remove EVC and OVC related attributes.




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   o  Remove Metro-Network related attributes.

   o  Remove Customer Account Number attributes.

   o  Update L2VPN service Types.

   o  Remove load banlancing options since access-priority within
      availability can be used to support load balancing.

   o  Remove service protection attribute since we have site diversity
      attributes.

   o  Move SVC-MTU to service level.

   o  Move CVLAN to Service Mapping to Network Access Level.

   o  Add two new parameters under qos-classification-policy.

   o  Remove Security Container.

   o  Remove IPv4/IPv6 prefix filter from VPN policy.

   o  Add Delivery mode support at service level.

   Changes in v-(05) include:

   o  Change type from 16-bit integer to string for the leaf id under
      "qos-classification-policy" container.

   o  Stick to using ordered-by user and remove inefficiency to map
      service model sequence number to device model sequence number.

   o  Remove mandating the use of deviations and add "if-feature target-
      sites" under the leaf-list target-sites in section 5.10.2.

   o  RFC2119 language changes on operation of the management system in
      Section 5.6,3rd paragraph and section 7.

   o  Fix incomplete description statements.

   o  Change the use of the absolute paths to the use of relative paths
      in the "must" statement or "path" statement for vpn-policy-id leaf
      node, management container, location leaf node, devices container,
      location case, location-reference leaf, device case, device-
      reference leaf to make configuration is only applicable to the
      current sites.





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   o  Change "must" statement to "when" statement for management
      container device container.

   o  Define new grouping vpn-profile-cfg for all the identifiers
      provided by SP to the customer.  The identifiers include cloud-
      identifier, std-qos-profile.

   o  Add in the XPATH string representation and remove unqualified
      name.

   o  Remove redundant parameters in the cloud access.

   o  Add a few text to clarify what the site is in section 6.3.

   o  Add multi-filter and multi-VPN per entry support for VPN policy.

   o  Modify description for svc-bandwidth leaf to make it consistent
      with the text in section 5.10.1.

   o  Add text to clarify the way to achieve Per-VPN QoS policy.

   o  Change guaranteed-bw-percent data type from uint8 to decimal64.

Authors' Addresses

   Bin Wen
   Comcast

   Email: bin_wen@comcast.com


   Giuseppe Fioccola (editor)
   Telecom Italia

   Email: giuseppe.fioccola@telecomitalia.it


   Chongfeng Xie
   China Telecom

   Email: xiechf@ctbri.com.cn


   Luay Jalil
   Verizon

   Email: luay.jalil@verizon.com




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