[Docs] [txt|pdf|xml|html] [Tracker] [WG] [Email] [Diff1] [Diff2] [Nits]

Versions: (draft-chen-nvo3-gap-analysis) 00 01

Internet Engineering Task Force                             E. Gray, Ed.
Internet-Draft                                                  Ericsson
Intended status: Informational                                  N. Bitar
Expires: August 18, 2014                                         Verizon
                                                                 X. Chen
                                                     Huawei Technologies
                                                             M. Lasserre
                                                          Alcatel-Lucent
                                                                 T. Tsou
                                               Huawei Technologies (USA)
                                                       February 14, 2014


  NVO3 Gap Analysis - Requirements Versus Available Technology Choices
                    draft-ietf-nvo3-gap-analysis-01

Abstract

   This document evaluates candidate protocols against the NVO3
   requirements.  Gaps are identified and further work recommended.

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 http://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 August 18, 2014.

Copyright Notice

   Copyright (c) 2014 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
   (http://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



Gray, et al.             Expires August 18, 2014                [Page 1]


Internet-Draft              NVO3 Gap Analysis              February 2014


   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  . . . . . . . . . . . . . . . . . . . . . . . .   2
   2.  Terminology and Conventions . . . . . . . . . . . . . . . . .   3
     2.1.  Requirements Language . . . . . . . . . . . . . . . . . .   3
     2.2.  Conventions . . . . . . . . . . . . . . . . . . . . . . .   3
     2.3.  Terms and Abbreviations . . . . . . . . . . . . . . . . .   3
   3.  Operational Requirements  . . . . . . . . . . . . . . . . . .   4
   4.  Management Requirements . . . . . . . . . . . . . . . . . . .   4
   5.  Control Plane Requirements  . . . . . . . . . . . . . . . . .   4
     5.1.  NVE-NVA Control-Plane Requirements  . . . . . . . . . . .   6
     5.2.  VM-to-NVE Specific Control-Plane Requirements . . . . . .   9
   6.  Data Plane Requirements . . . . . . . . . . . . . . . . . . .  11
   7.  Summary and Conclusions . . . . . . . . . . . . . . . . . . .  17
   8.  Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .  17
   9.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .  18
   10. Security Considerations . . . . . . . . . . . . . . . . . . .  18
   11. References  . . . . . . . . . . . . . . . . . . . . . . . . .  18
     11.1.  Normative References . . . . . . . . . . . . . . . . . .  18
     11.2.  Informative References . . . . . . . . . . . . . . . . .  20
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  20

1.  Introduction

   The initial charter of the NVO3 Working Group requires it to identify
   any gaps between the requirements identified and available
   technoloogy solutions as a prerequisite to rechartering or concluding
   the Working Group (if no gaps exist).  This document is intended to
   provide the required gap analysis.

   This document provides a tabulation of candidate solutions and their
   ability to satisfy each requirement identified by the Working Group.

   Areas of work are identified where further work is required to ensure
   that the requirements are met.

   The major areas covered in this document include:

   o  Operational Requirements
      [I-D.ashwood-nvo3-operational-requirement]

   o  Management Requirements (TBD)




Gray, et al.             Expires August 18, 2014                [Page 2]


Internet-Draft              NVO3 Gap Analysis              February 2014


   o  Control (Plane) Requirements [I-D.ietf-nvo3-nve-nva-cp-req]

   o  Dataplane Requirements [I-D.ietf-nvo3-dataplane-requirements]

   Since the Working Group has yet to complete (and in some cases adopt)
   documents describing requirements for some of these areas, not all
   areas are complete in the present version of this document.

   The initial candidate technologies are:

   o  NVGRE [I-D.sridharan-virtualization-nvgre],

   o  VxLAN [I-D.mahalingam-dutt-dcops-vxlan],

   o  L2VPN: VPLS [RFC4761][RFC4762] and EVPN [I-D.ietf-l2vpn-evpn], and

   o  L3VPN [RFC4365].

2.  Terminology and Conventions

2.1.  Requirements Language

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
   document are to be interpreted as described in RFC 2119 [RFC2119].

2.2.  Conventions

   In sections providing analysis of requirements defined in referenced
   documents, section numbers from each referenced document are used as
   they were listed in that document.

   In order to avoid confusing those section numbers with the section
   numbering in this document, the included numbering is parenthesized.

   L2VPN is represented (in tables and analysis, as a technology) by the
   two differing approaches: VPLS and EVPN.

2.3.  Terms and Abbreviations

   This document uses terms and acronyms defined in [RFC3168],
   [I-D.ietf-nvo3-framework], [I-D.ietf-nvo3-dataplane-requirements],
   [I-D.kreeger-nvo3-hypervisor-nve-cp] and
   [I-D.ietf-nvo3-nve-nva-cp-req].  Acronyms are included here for
   convenience but are meant to remain aligned with definitions in the
   references included.

   ECN:  Explicit Congestion Notification [RFC3168]



Gray, et al.             Expires August 18, 2014                [Page 3]


Internet-Draft              NVO3 Gap Analysis              February 2014


   NVA:  Network Virtualization Authority [I-D.ietf-nvo3-nve-nva-cp-req]

   NVE:  Network Virtualization Edge [I-D.ietf-nvo3-framework]

   VAP:  Virtual Access Point [I-D.ietf-nvo3-dataplane-requirements]

   VNI:  Virtual Network Instance [I-D.ietf-nvo3-framework]

   VNIC:  Virtual Network Interface Card (NIC)
      [I-D.kreeger-nvo3-hypervisor-nve-cp]

   VNID:  Virtual Network Identifier [I-D.ietf-nvo3-nve-nva-cp-req]

   This document uses the following additional general terms and
   abbreviations:

   DSCP:  Differentiated Services Code-Point

   ECMP:  Equal Cost Multi-Path

   L2VPN:  Layer 2 Virtual Private Network

   L3VPN:  Layer 3 Virtual Private Network

   NVO3:  Network Virtualization Overlay over L3

   VM:  Virtual Machine

   VN:  Virtual Network

3.  Operational Requirements

   TBD

4.  Management Requirements

   TBD

5.  Control Plane Requirements

   The NVO3 Problem Statement [I-D.ietf-nvo3-overlay-problem-statement],
   describes 3 categories of control functions:

   1.  Control functions associated with implementing the Network
       Virtualization Authority (e.g. - signaling and control required
       for interactions between multiple NVA devices).





Gray, et al.             Expires August 18, 2014                [Page 4]


Internet-Draft              NVO3 Gap Analysis              February 2014


   2.  Control functions associated with interactions between an NVA and
       a Network Virtualization Edge (NVE).

   3.  Control functions associated with attaching and detaching a
       Virtual Machine (VM) from a particular Virtual Network Instance
       (VNI).

   As sometimes happens, there is not a 1:1 mapping of the work areas
   defined in [I-D.ietf-nvo3-overlay-problem-statement] and requirements
   documents intended to address the problems that have been identified
   there.

   Current control-plane requirement documents include the following:

   o  NVE-NVA control-plane requirements [I-D.ietf-nvo3-nve-nva-cp-req]

   o  Control-plane requirements specific to VM-to-NVE interactions
      [I-D.kreeger-nvo3-hypervisor-nve-cp]

   In the following subsections, we consider the data-plane candidate
   solutions and proposed or existing control plane solutions that may
   apply to each.

   In each case, the control-plane solutions can be divided into support
   for Layer-2 and Layer-3 services, and for each of these cases, the
   data-plane solutions considered will be limited to those services and
   solutions that make sense for that case.

   Tables are thus organized into separate tables for both L2 and L3
   data/control service options.  It may turn out that - for all
   potential control-plane solutions - each solution applies equally to
   all data-plane solutions considered for the layer applicable.

   If this turns out to be the case, then the tables may be further
   simplified - possibly by reducing each pair of L2/L3 tables to a
   single table where the columns are simply "Layer-2" and "Layer-3."

   The intent is to show potential mapping of data-plane to applicable
   control-plane alternatives and evaluate each applicable control-plane
   against defined control-plane requirements.

   The way this document attempts to do this is to list the control
   planes that may be applicable to each of the candidate data-planes in
   table footnotes and then stating in table footnotes the extent to
   which candidate control plane technologies satisfy each requirement.






Gray, et al.             Expires August 18, 2014                [Page 5]


Internet-Draft              NVO3 Gap Analysis              February 2014


   As with tables in other sections of this draft, the rows in each
   table list the applicable requirements found in analogous sections of
   applicable requirements documents.

5.1.  NVE-NVA Control-Plane Requirements

   In this section, numbering of requirement headings corresponds to
   section numbering in [I-D.ietf-nvo3-nve-nva-cp-req].

   (3.1) Inner to Outer Address Mapping

   The requirements document [I-D.ietf-nvo3-nve-nva-cp-req] states that
   avoiding the need to "flood" traffic to support learning of mapping
   information from the data-plane is a goal of NVO3 candidate
   technological approaches.

   For each candidate technology, (how) is the mapping of header
   information present in tenant traffic mapped to corresponding header
   information to be used in overlay encapsulation (this includes
   addresses, context identification, etc.) determined?

     +---------------------------------------+-------+-------+-------+
     | Supported Approach                    | VxLAN |  VPLS |  EVPN |
     +---------------------------------------+-------+-------+-------+
     | Control Protocol Mapping Acquisition? |       |       |       |
     | - - -                                 | - - - | - - - |  - -  |
     | Data-Plane Learning?                  |       |       |       |
     +---------------------------------------+-------+-------+-------+

                 Table 1: Inner:Outer Address Mapping (L2)

         +---------------------------------------+-------+-------+
         | Supported Approach                    | NVGRE | L3VPN |
         +---------------------------------------+-------+-------+
         | Control Protocol Mapping Acquisition? |       |       |
         | - - -                                 | - - - | - - - |
         | Data-Plane Learning?                  |       |       |
         +---------------------------------------+-------+-------+

                 Table 2: Inner:Outer Address Mapping (L3)

   (3.2) Underlying Network Multi-Destination Address(es)

   The requirements document [I-D.ietf-nvo3-nve-nva-cp-req] lists 3
   approaches that may be used to deliver traffic to multiple
   destinations in an overlay virtual network:

   1.  Use the capabilities of the underlay network.



Gray, et al.             Expires August 18, 2014                [Page 6]


Internet-Draft              NVO3 Gap Analysis              February 2014


   2.  Require a sending NVE to replicate traffic.

   3.  Use a replication service provided within the overlay network.

   For each delivery approach, it may be necessary to map specific
   multipoint (e.g. - broadcast, unknown destination or multicast)
   traffic to (for instance) addresses used to deliver this traffic via
   the underlay network.

   For each technological approach, which delivery approaches are
   supported and does the technology provide a method by which an NVE
   needing to send multi-destination traffic can determine to what
   address, or addresses to which to send this traffic?

      +------------------------------------+-------+-------+-------+
      | Supported Approach                 | VxLAN |  VPLS |  EVPN |
      +------------------------------------+-------+-------+-------+
      | Underlay Network Capability        |       |       |       |
      | - - -                              | - - - | - - - | - - - |
      | NVE Sender Replication             |       |       |       |
      | - - -                              | - - - | - - - | - - - |
      | Replication Service                |       |       |       |
      +------------------------------------+-------+-------+-------+

                 Table 3: Multi-Destination Delivery (L2)

         +--------------------------------------+-------+-------+
         | Supported Approach                   | NVGRE | L3VPN |
         +--------------------------------------+-------+-------+
         | Underlay Network Capability          |       |       |
         | - - -                                | - - - | - - - |
         | NVE Sender Replication               |       |       |
         | - - -                                | - - - | - - - |
         | Replication Service                  |       |       |
         +--------------------------------------+-------+-------+

                 Table 4: Multi-Destination Delivery (L3)

   (3.3) VN Connect/Disconnect Notification

   The requirements document [I-D.ietf-nvo3-nve-nva-cp-req] states as an
   assumption that a mechanism exists in the overlay technology by which
   an NVE is notified of Tenant Systems attaching and detaching from a
   specific Virtual Network (VN).

   For each candidate technology, does the technology currently support
   these functions?




Gray, et al.             Expires August 18, 2014                [Page 7]


Internet-Draft              NVO3 Gap Analysis              February 2014


      +------------------------------------+-------+-------+-------+
      | Requirement                        | VxLAN |  VPLS |  EVPN |
      +------------------------------------+-------+-------+-------+
      | Connect Notification               |       |       |       |
      | - - -                              | - - - | - - - | - - - |
      | Disconnect Notification            |       |       |       |
      +------------------------------------+-------+-------+-------+

               Table 5: Connect/Disconnect Notification (L2)

         +--------------------------------------+-------+-------+
         | Requirement                          | NVGRE | L3VPN |
         +--------------------------------------+-------+-------+
         | Connect Notification                 |       |       |
         | - - -                                | - - - | - - - |
         | Disconnect Notification              |       |       |
         +--------------------------------------+-------+-------+

               Table 6: Connect/Disconnect Notification (L3)

   (3.4) VN Name to VNID Mapping

   The requirements document [I-D.ietf-nvo3-nve-nva-cp-req] concludes
   that having a means to map for a "VN Name to a "VN ID" may be useful.

   For each technological approach we are considering, is this function
   currently available?

      +------------------------------------+-------+-------+-------+
      | Function                           | VxLAN |  VPLS |  EVPN |
      +------------------------------------+-------+-------+-------+
      | VN-Name:VN-ID Mapping              |       |       |       |
      +------------------------------------+-------+-------+-------+

                  Table 7: VN Name to VN ID Mapping (L2)

         +--------------------------------------+-------+-------+
         | Function                             | NVGRE | L3VPN |
         +--------------------------------------+-------+-------+
         | VN-Name:VN-ID Mapping                |       |       |
         +--------------------------------------+-------+-------+

                  Table 8: VN Name to VN ID Mapping (L3)








Gray, et al.             Expires August 18, 2014                [Page 8]


Internet-Draft              NVO3 Gap Analysis              February 2014


5.2.  VM-to-NVE Specific Control-Plane Requirements

   In this section, numbering of requirement headings corresponds to
   section numbering in [I-D.kreeger-nvo3-hypervisor-nve-cp].

   (4.1) VN Connect/Disconnect

   The requirements document [I-D.kreeger-nvo3-hypervisor-nve-cp] states
   as a requirement that a mechanism must exist by which an NVE is
   notified when an end device requires a connection, or no longer
   requires a connection, to a specific Virtual Network (VN).

   The requirements document further states as a requirement that the
   mechanism(s) used in a candidate technological approach must provide
   a local indicator (e.g. - 802.1Q tag) that the end device will use in
   sending traffic to, or receiving traffic from, the NVE (where that
   traffic is associated with the connected VN).

   As an additional related requirement, the requirements document
   states that the NVE - once notified of a connection to a VN (by VN
   Name), needs to have a means for getting associated VN context
   information from the NVA.

   For each candidate technology, does the technology currently support
   these functions?

      +------------------------------------+-------+-------+-------+
      | Requirement                        | VxLAN |  VPLS |  EVPN |
      +------------------------------------+-------+-------+-------+
      | Connect Notification               |       |       |       |
      | - - -                              | - - - | - - - | - - - |
      | Local VN Indicator                 |       |       |       |
      | - - -                              | - - - | - - - | - - - |
      | VN Name to VN Context Mapping      |       |       |       |
      | - - -                              | - - - | - - - | - - - |
      | Disconnect Notification            |       |       |       |
      +------------------------------------+-------+-------+-------+

                    Table 9: VN Connect/Disconnect (L2)












Gray, et al.             Expires August 18, 2014                [Page 9]


Internet-Draft              NVO3 Gap Analysis              February 2014


         +--------------------------------------+-------+-------+
         | Requirement                          | NVGRE | L3VPN |
         +--------------------------------------+-------+-------+
         | Connect Notification                 |       |       |
         | - - -                                | - - - | - - - |
         | Local VN Indicator                   |       |       |
         | - - -                                | - - - | - - - |
         | VN Name to VN Context Mapping        |       |       |
         | - - -                                | - - - | - - - |
         | Disconnect Notification              |       |       |
         +--------------------------------------+-------+-------+

                   Table 10: VN Connect/Disconnect (L3)

   (4.2) VNIC Address Association

   The requirements document [I-D.kreeger-nvo3-hypervisor-nve-cp] lists
   two approaches for acquiring VNIC address association information:

   1.  Data Plane Learning (i.e. - by inspecting source addresses in
       traffic received from an end device).

   2.  Explicit signaling from the end device when a specific VNIC
       address is to be associated with a tenant system.

      +------------------------------------+-------+-------+-------+
      | Supported Approaches               | VxLAN |  VPLS |  EVPN |
      +------------------------------------+-------+-------+-------+
      | Data Plane Learning                |       |       |       |
      | - - -                              | - - - | - - - | - - - |
      | Explicit Signaling                 |       |       |       |
      +------------------------------------+-------+-------+-------+

                  Table 11: VNIC Address Association (L2)

         +--------------------------------------+-------+-------+
         | Supported Approaches                 | NVGRE | L3VPN |
         +--------------------------------------+-------+-------+
         | Data Plane Learning                  |       |       |
         | - - -                                | - - - | - - - |
         | Explicit Signaling                   |       |       |
         +--------------------------------------+-------+-------+

                  Table 12: VNIC Address Association (L3)

   (4.3) VNIC Address Disassociation

   TBD



Gray, et al.             Expires August 18, 2014               [Page 10]


Internet-Draft              NVO3 Gap Analysis              February 2014


   (4.4) VNIC Shutdown/Startup/Migration

   TBD

   (4.5) VN Profile

   TBD

6.  Data Plane Requirements

   In this section, numbering of requirement headings corresponds to
   section numbering in [I-D.ietf-nvo3-dataplane-requirements].

   (3.1) Virtual Access Points (VAPs)

   +-----------------------------+-------+-------+------+------+-------+
   | Requirement                 | NVGRE | VxLAN | VPLS | EVPN | L3VPN |
   +-----------------------------+-------+-------+------+------+-------+
   | MUST support VAP            |       |       |      |      |       |
   | identification              |       |       |      |      |       |
   | - - -                       | - - - | - - - | - -  | - -  | - - - |
   | 1) Local interface          |  YES  |       |      |      |       |
   | - - -                       | - - - | - - - | - -  | - -  | - - - |
   | 2) Local interface + fields |  YES  |       |      |      |       |
   | in frame header             |       |       |      |      |       |
   +-----------------------------+-------+-------+------+------+-------+

                 Table 13: VAP Identification Requirements

   (3.2) Virtual Network Instance (VNI)

   Network virtualization can be provided by L2 and/or L3 VNIs.

   (3.2.1) L2 VNI

















Gray, et al.             Expires August 18, 2014               [Page 11]


Internet-Draft              NVO3 Gap Analysis              February 2014


   +-----------------------------+-------+-------+------+------+-------+
   | Requirement                 | NVGRE | VxLAN | VPLS | EVPN | L3VPN |
   +-----------------------------+-------+-------+------+------+-------+
   | L2 VNI MUST provide an      |       |       |      |      |       |
   | emulated Ethernet           |       |       |      |      |       |
   | multipoint service as if    |       |       |      |      |       |
   | Tenant Systems are          |       |       |      |      |       |
   | interconnected by a bridge  |       |       |      |      |       |
   | (but instead by using a set |       |       |      |      |       |
   | of NVO3 tunnels).           |       |       |      |      |       |
   | - - -                       | - - - | - - - | - -  | - -  | - - - |
   | Loop avoidance capability   |       |       |      |      |       |
   | MUST be provided.           |       |       |      |      |       |
   | - - -                       | - - - | - - - | - -  | - -  | - - - |
   | Data plane learning MUST be |       |       |      |      |       |
   | supported as the default    |       |       |      |      |       |
   | means to populate           |       |       |      |      |       |
   | forwarding tables.          |       |       |      |      |       |
   | - - -                       | - - - | - - - | - -  | - -  | - - - |
   | When flooding is required   |       |       |      |      |       |
   | for delivery of broadcast,  |       |       |      |      |       |
   | unknown unicast or          |       |       |      |      |       |
   | multicast (BUM) traffic,    |       |       |      |      |       |
   | the NVE MUST either support |       |       |      |      |       |
   | ingress replication or      |       |       |      |      |       |
   | multicast.                  |       |       |      |      |       |
   | - - -                       | - - - | - - - | - -  | - -  | - - - |
   | If using multicast, the NVE |       |       |      |      |       |
   | MUST be able to build at    |       |       |      |      |       |
   | least one default flooding  |       |       |      |      |       |
   | tree for use by local VNIs  |       |       |      |      |       |
   | for flooding to NVEs        |       |       |      |      |       |
   | belonging to the same VN.   |       |       |      |      |       |
   +-----------------------------+-------+-------+------+------+-------+

                         Table 14: L2 VNI Service

   (3.2.2) L3 VNI













Gray, et al.             Expires August 18, 2014               [Page 12]


Internet-Draft              NVO3 Gap Analysis              February 2014


   +-----------------------------+-------+-------+------+------+-------+
   | Requirement                 | NVGRE | VxLAN | VPLS | EVPN | L3VPN |
   +-----------------------------+-------+-------+------+------+-------+
   | L3 VNIs MUST provide        |       |       |      |      |       |
   | virtualized IP routing and  |       |       |      |      |       |
   | forwarding.                 |       |       |      |      |       |
   | - - -                       | - - - | - - - | - -  | - -  | - - - |
   | L3 VNIs MUST support per-   |       |       |      |      |       |
   | tenant forwarding instance  |       |       |      |      |       |
   | with IP addressing          |       |       |      |      |       |
   | isolation and L3 tunneling  |       |       |      |      |       |
   | for interconnecting         |       |       |      |      |       |
   | instances of the same VNI   |       |       |      |      |       |
   | on NVEs.                    |       |       |      |      |       |
   | - - -                       | - - - | - - - | - -  | - -  | - - - |
   | For L3 VNI, the inner TTL   |       |       |      |      |       |
   | field MUST be decremented   |       |       |      |      |       |
   | by at least 1 (as if the    |       |       |      |      |       |
   | NVO3 egress was at least 1  |       |       |      |      |       |
   | hop away).                  |       |       |      |      |       |
   | - - -                       | - - - | - - - | - -  | - -  | - - - |
   | TTL in the outer IP header  |       |       |      |      |       |
   | MUST be set to a value      |       |       |      |      |       |
   | appropriate for delivery of |       |       |      |      |       |
   | the encapsulated packet to  |       |       |      |      |       |
   | the tunnel exit point.      |       |       |      |      |       |
   | - - -                       | - - - | - - - | - -  | - -  | - - - |
   | The default behavior for    |       |       |      |      |       |
   | TTL MUST use the "pipe"     |       |       |      |      |       |
   | model.                      |       |       |      |      |       |
   +-----------------------------+-------+-------+------+------+-------+

                         Table 15: L3 VNI Service

   (3.3.1) NVO3 overlay header

   +-----------------------------+-------+-------+------+------+-------+
   | Requirement                 | NVGRE | VxLAN | VPLS | EVPN | L3VPN |
   +-----------------------------+-------+-------+------+------+-------+
   | An NVO3 overlay header MUST |  YES  |  YES  | YES  | YES  |  YES  |
   | be included after the       |       |       |      |      |       |
   | underlay tunnel header when |       |       |      |      |       |
   | forwarding tenant traffic.  |       |       |      |      |       |
   +-----------------------------+-------+-------+------+------+-------+

                         Table 16: Overlay Header

   (3.3.1.1) Virtual Network Context Identification



Gray, et al.             Expires August 18, 2014               [Page 13]


Internet-Draft              NVO3 Gap Analysis              February 2014


   +-----------------------------+-------+-------+------+------+-------+
   | Requirement                 | NVGRE | VxLAN | VPLS | EVPN | L3VPN |
   +-----------------------------+-------+-------+------+------+-------+
   | The overlay encapsulation   |  YES  |  YES  | YES  | YES  |  YES  |
   | header MUST contain a field |       |       |      |      |       |
   | which allows the            |       |       |      |      |       |
   | encapsulated frame to be    |       |       |      |      |       |
   | delivered to the            |       |       |      |      |       |
   | appropriate virtual network |       |       |      |      |       |
   | endpoint by the egress NVE. |       |       |      |      |       |
   | .                           |       |       |      |      |       |
   | - - -                       | - - - | - - - | - -  | - -  | - - - |
   | If Global Identifiers are   |       |       |      |      |       |
   | used, the identifier field  |       |       |      |      |       |
   | MUST be large enough to     |       |       |      |      |       |
   | scale to hundreds of        |       |       |      |      |       |
   | thousands of VNs.           |       |       |      |      |       |
   +-----------------------------+-------+-------+------+------+-------+

             Table 17: Virtual Network Context Identification

   (3.3.2.1) LAG and ECMP

   +-----------------------------+-------+-------+------+------+-------+
   | Requirement                 | NVGRE | VxLAN | VPLS | EVPN | L3VPN |
   +-----------------------------+-------+-------+------+------+-------+
   | In order to perform fine-   |       |       |      |      |       |
   | grained load-balancing, the |       |       |      |      |       |
   | data-plane encapsulation    |       |       |      |      |       |
   | MUST result in sufficient   |       |       |      |      |       |
   | entropy to exercise all     |       |       |      |      |       |
   | paths through several       |       |       |      |      |       |
   | LAG/ECMP hops.              |       |       |      |      |       |
   | - - -                       | - - - | - - - | - -  | - -  | - - - |
   | All packets belonging to    |   NO  |       |      |      |       |
   | any specific flow MUST      |       |       |      |      |       |
   | follow the same path in     |       |       |      |      |       |
   | order to prevent packet re- |       |       |      |      |       |
   | ordering.                   |       |       |      |      |       |
   +-----------------------------+-------+-------+------+------+-------+

                        Table 18: Multipath Support

   (3.3.2.2) DiffServ and ECN marking







Gray, et al.             Expires August 18, 2014               [Page 14]


Internet-Draft              NVO3 Gap Analysis              February 2014


   +-----------------------------+-------+-------+------+------+-------+
   | Requirement                 | NVGRE | VxLAN | VPLS | EVPN | L3VPN |
   +-----------------------------+-------+-------+------+------+-------+
   | [RFC2983] defines two modes |   NO  |       |      |      |       |
   | for mapping the DSCP        |       |       |      |      |       |
   | markings from inner to      |       |       |      |      |       |
   | outer headers and vice      |       |       |      |      |       |
   | versa. Both models SHOULD   |       |       |      |      |       |
   | be supported.               |       |       |      |      |       |
   +-----------------------------+-------+-------+------+------+-------+

                      Table 19: DSCP and ECN Marking

   (3.3.2.3) Handling of broadcast, unknown unicast, and multicast
   traffic

   NVO3 data plane support for either ingress replication or point-to-
   multipoint tunnels is required to send traffic destined to multiple
   locations on a per-VNI basis (e.g. L2/L3 multicast traffic, L2
   broadcast and unknown unicast traffic).  It is possible that both
   methods be used simultaneously.

   +-----------------------------+-------+-------+------+------+-------+
   | Requirement                 | NVGRE | VxLAN | VPLS | EVPN | L3VPN |
   +-----------------------------+-------+-------+------+------+-------+
   | User-configurable knobs     |       |       |      |      |       |
   | MUST be provided to select  |       |       |      |      |       |
   | which method(s) are used    |       |       |      |      |       |
   | based upon the amount of    |       |       |      |      |       |
   | replication required.       |       |       |      |      |       |
   | - - -                       | - - - | - - - | - -  | - -  | - - - |
   | When ingress replication is |       |       |      |      |       |
   | used, NVEs MUST track       |       |       |      |      |       |
   | maintain (for each VNI) the |       |       |      |      |       |
   | related tunnel endpoints to |       |       |      |      |       |
   | which it needs to replicate |       |       |      |      |       |
   | the frame.                  |       |       |      |      |       |
   +-----------------------------+-------+-------+------+------+-------+

      Table 20: Handling of Broadcast, Unknown Unicast, and Multicast
                                  Traffic

   (3.4) External NVO3 connectivity








Gray, et al.             Expires August 18, 2014               [Page 15]


Internet-Draft              NVO3 Gap Analysis              February 2014


   +-----------------------------+-------+-------+------+------+-------+
   | Requirement                 | NVGRE | VxLAN | VPLS | EVPN | L3VPN |
   +-----------------------------+-------+-------+------+------+-------+
   | NVO3 services MUST          |  YES  |       |      |      |       |
   | interoperate with current   |       |       |      |      |       |
   | VPN and Internet services.  |       |       |      |      |       |
   | This may happen inside one  |       |       |      |      |       |
   | DC during a migration phase |       |       |      |      |       |
   | or as NVO3 services are     |       |       |      |      |       |
   | delivered to the outside    |       |       |      |      |       |
   | world via Internet or VPN   |       |       |      |      |       |
   | gateways.                   |       |       |      |      |       |
   | - - -                       | - - - | - - - | - -  | - -  | - - - |
   | Redundancy between NVO3 and |       |       |      |      |       |
   | external domains MUST be    |       |       |      |      |       |
   | supported.                  |       |       |      |      |       |
   +-----------------------------+-------+-------+------+------+-------+

                         Table 21: Interoperation

   (3.4.2.1) Load-balancing

   When using active-active load-balancing across physically separate
   NVE GW's (e.g.: two, separate chassis) an NVO3 solution SHOULD
   support forwarding tables that can simultaneously map a single egress
   NVE to more than one NVO3 tunnels.

   +-----------------------------+-------+-------+------+------+-------+
   | Requirement                 | NVGRE | VxLAN | VPLS | EVPN | L3VPN |
   +-----------------------------+-------+-------+------+------+-------+
   | The granularity of such     |       |       |      |      |       |
   | mappings, in both active-   |       |       |      |      |       |
   | backup and active-active,   |       |       |      |      |       |
   | MUST be specific to each    |       |       |      |      |       |
   | tenant.                     |       |       |      |      |       |
   +-----------------------------+-------+-------+------+------+-------+

                     Table 22: Gateway Load-balancing

   (3.5) Path MTU











Gray, et al.             Expires August 18, 2014               [Page 16]


Internet-Draft              NVO3 Gap Analysis              February 2014


   +-----------------------------+-------+-------+------+------+-------+
   | Requirement                 | NVGRE | VxLAN | VPLS | EVPN | L3VPN |
   +-----------------------------+-------+-------+------+------+-------+
   | Classical ICMP-based MTU    |   NO  |       |      |      |       |
   | Path Discovery ([RFC1191],  |       |       |      |      |       |
   | [RFC1981]) or Extended MTU  |       |       |      |      |       |
   | Path Discovery techniques   |       |       |      |      |       |
   | such as defined in          |       |       |      |      |       |
   | [RFC4821].                  |       |       |      |      |       |
   | - - -                       | - - - | - - - | - -  | - -  | - - - |
   | Fragmentation and           |  YES  |       |      |      |       |
   | reassembly support from the |       |       |      |      |       |
   | overlay layer operations    |       |       |      |      |       |
   | without relying on the      |       |       |      |      |       |
   | Tenant Systems to know      |       |       |      |      |       |
   | about the end-to-end MTU.   |       |       |      |      |       |
   +-----------------------------+-------+-------+------+------+-------+

                            Table 23: Path MTU

   (3.7) NVE Multi-Homing Requirements

   +-----------------------------+-------+-------+------+------+-------+
   | Requirement                 | NVGRE | VxLAN | VPLS | EVPN | L3VPN |
   +-----------------------------+-------+-------+------+------+-------+
   | Multi-homing techniques     |   NO  |       |      |      |       |
   | SHOULD be used to increase  |       |       |      |      |       |
   | the reliability of an NVO3  |       |       |      |      |       |
   | network.                    |       |       |      |      |       |
   +-----------------------------+-------+-------+------+------+-------+

                           Table 24: Multihoming

7.  Summary and Conclusions

   TBD

8.  Acknowledgements

   The Authors would like to acknowledge the technical contributions of
   Florin Balus, Luyuan Fang, Sue Hares, Wim Henderickx, Yves Hertoghs,
   Yuichi Ikejiri, Rangaraju Iyengar, Mircea Pisica, Evelyn Roch, Ali
   Sajassi, Peter Ashwood-Smith and Lucy Yong as well as the initial
   help in editing the XML source for the document from Tom Taylor.







Gray, et al.             Expires August 18, 2014               [Page 17]


Internet-Draft              NVO3 Gap Analysis              February 2014


9.  IANA Considerations

   This memo includes no request to IANA.

10.  Security Considerations

   Security considerations of the requirements documents referenced by
   this analysis document apply.

11.  References

11.1.  Normative References

   [I-D.ashwood-nvo3-operational-requirement]
              Ashwood-Smith, P., Iyengar, R., Tsou, T., Sajassi, A.,
              Boucadair, M., Jacquenet, C., and M. Daikoku, "NVO3
              Operational Requirements", draft-ashwood-nvo3-operational-
              requirement-03 (work in progress), July 2013.

   [I-D.hertoghs-nvo3-lisp-controlplane-unified]
              Hertoghs, Y., Maino, F., Moreno, V., Smith, M., Farinacci,
              D., and L. Iannone, "A Unified LISP Mapping Database for
              L2 and L3 Network Virtualization Overlays", draft-
              hertoghs-nvo3-lisp-controlplane-unified-01 (work in
              progress), February 2014.

   [I-D.ietf-l2vpn-evpn]
              Sajassi, A., Aggarwal, R., Henderickx, W., Isaac, A., and
              J. Uttaro, "BGP MPLS Based Ethernet VPN", draft-ietf-
              l2vpn-evpn-05 (work in progress), February 2014.

   [I-D.ietf-nvo3-dataplane-requirements]
              Bitar, N., Lasserre, M., Balus, F., Morin, T., Jin, L.,
              and B. Khasnabish, "NVO3 Data Plane Requirements", draft-
              ietf-nvo3-dataplane-requirements-02 (work in progress),
              November 2013.

   [I-D.ietf-nvo3-framework]
              Lasserre, M., Balus, F., Morin, T., Bitar, N., and Y.
              Rekhter, "Framework for DC Network Virtualization", draft-
              ietf-nvo3-framework-05 (work in progress), January 2014.

   [I-D.ietf-nvo3-nve-nva-cp-req]
              Kreeger, L., Dutt, D., Narten, T., and D. Black, "Network
              Virtualization NVE to NVA Control Protocol Requirements",
              draft-ietf-nvo3-nve-nva-cp-req-01 (work in progress),
              October 2013.




Gray, et al.             Expires August 18, 2014               [Page 18]


Internet-Draft              NVO3 Gap Analysis              February 2014


   [I-D.ietf-nvo3-overlay-problem-statement]
              Narten, T., Gray, E., Black, D., Fang, L., Kreeger, L.,
              and M. Napierala, "Problem Statement: Overlays for Network
              Virtualization", draft-ietf-nvo3-overlay-problem-
              statement-04 (work in progress), July 2013.

   [I-D.kreeger-nvo3-hypervisor-nve-cp]
              Kreeger, L., Narten, T., and D. Black, "Network
              Virtualization Hypervisor-to-NVE Overlay Control Protocol
              Requirements", draft-kreeger-nvo3-hypervisor-nve-cp-01
              (work in progress), February 2013.

   [I-D.mahalingam-dutt-dcops-vxlan]
              Mahalingam, M., Dutt, D., Duda, K., Agarwal, P., Kreeger,
              L., Sridhar, T., Bursell, M., and C. Wright, "VXLAN: A
              Framework for Overlaying Virtualized Layer 2 Networks over
              Layer 3 Networks", draft-mahalingam-dutt-dcops-vxlan-08
              (work in progress), February 2014.

   [I-D.sridharan-virtualization-nvgre]
              Sridharan, M., Greenberg, A., Wang, Y., Garg, P.,
              Venkataramiah, N., Duda, K., Ganga, I., Lin, G., Pearson,
              M., Thaler, P., and C. Tumuluri, "NVGRE: Network
              Virtualization using Generic Routing Encapsulation",
              draft-sridharan-virtualization-nvgre-04 (work in
              progress), February 2014.

   [RFC1191]  Mogul, J. and S. Deering, "Path MTU discovery", RFC 1191,
              November 1990.

   [RFC1981]  McCann, J., Deering, S., and J. Mogul, "Path MTU Discovery
              for IP version 6", RFC 1981, August 1996.

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119, March 1997.

   [RFC2983]  Black, D., "Differentiated Services and Tunnels", RFC
              2983, October 2000.

   [RFC4365]  Rosen, E., "Applicability Statement for BGP/MPLS IP
              Virtual Private Networks (VPNs)", RFC 4365, February 2006.

   [RFC4761]  Kompella, K. and Y. Rekhter, "Virtual Private LAN Service
              (VPLS) Using BGP for Auto-Discovery and Signaling", RFC
              4761, January 2007.






Gray, et al.             Expires August 18, 2014               [Page 19]


Internet-Draft              NVO3 Gap Analysis              February 2014


   [RFC4762]  Lasserre, M. and V. Kompella, "Virtual Private LAN Service
              (VPLS) Using Label Distribution Protocol (LDP) Signaling",
              RFC 4762, January 2007.

   [RFC4821]  Mathis, M. and J. Heffner, "Packetization Layer Path MTU
              Discovery", RFC 4821, March 2007.

   [RFC6040]  Briscoe, B., "Tunnelling of Explicit Congestion
              Notification", RFC 6040, November 2010.

11.2.  Informative References

   [RFC3168]  Ramakrishnan, K., Floyd, S., and D. Black, "The Addition
              of Explicit Congestion Notification (ECN) to IP", RFC
              3168, September 2001.

Authors' Addresses

   Eric Gray (editor)
   Ericsson
   120 Morris Avenue
   Pitman, New Jersey  08071
   USA

   Email: eric.gray@ericsson.com


   Nabil Bitar
   Verizon
   40 Sylvan Road
   Waltham, Massachusetts  02145
   USA

   Email: nabil.bitar@verizon.com


   Xiaoming Chen
   Huawei Technologies

   Email: ming.chen@huawei.com


   Marc Lasserre
   Alcatel-Lucent

   Email: marc.lasserre@alcatel-lucent.com





Gray, et al.             Expires August 18, 2014               [Page 20]


Internet-Draft              NVO3 Gap Analysis              February 2014


   Tina Tsou
   Huawei Technologies (USA)
   2330 Central Expressway
   Santa Clara, California  95050
   USA

   Phone: +1 408 330 4424
   Email: Tina.Tsou.Zouting@huawei.com
   URI:   http://tinatsou.weebly.com/contact.html










































Gray, et al.             Expires August 18, 2014               [Page 21]


Html markup produced by rfcmarkup 1.121, available from https://tools.ietf.org/tools/rfcmarkup/