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Versions: (draft-kumar-lime-yang-connectionless-oam) 00 01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 Draft is active
In: Auth48
Network Working Group                                           D. Kumar
Internet-Draft                                                     Cisco
Intended status: Standards Track                                 M. Wang
Expires: May 4, 2017                                               Q. Wu
                                                                  Huawei
                                                               R. Rahman
                                                             S. Raghavan
                                                                   Cisco
                                                        October 31, 2016


 Generic YANG Data Model for Connectionless Operations, Administration,
                     and Maintenance(OAM) protocols
               draft-ietf-lime-yang-connectionless-oam-02

Abstract

   This document presents a base YANG Data model for connectionless OAM
   protocols.  It provides a technology-independent abstraction of key
   OAM constructs for connectionless protocols.  The Based model
   presented here can be extended to include technology specific
   details.  This is leading to uniformity between OAM protocols and
   support nested OAM workflows (i.e., performing OAM functions at
   different or same levels through a unified interface).

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 May 4, 2017.

Copyright Notice

   Copyright (c) 2016 IETF Trust and the persons identified as the
   document authors.  All rights reserved.





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   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
   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.  Conventions used in this document . . . . . . . . . . . . . .   3
     2.1.  Terminology . . . . . . . . . . . . . . . . . . . . . . .   4
     2.2.  Tree Diagrams . . . . . . . . . . . . . . . . . . . . . .   4
   3.  Overview of the Connectionless OAM Model  . . . . . . . . . .   5
     3.1.  TP Address  . . . . . . . . . . . . . . . . . . . . . . .   5
     3.2.  Tools . . . . . . . . . . . . . . . . . . . . . . . . . .   6
     3.3.  OAM-layers  . . . . . . . . . . . . . . . . . . . . . . .   6
     3.4.  Test Point Locations Information  . . . . . . . . . . . .   7
     3.5.  Test Point Locations  . . . . . . . . . . . . . . . . . .   7
     3.6.  Path Discovery Data . . . . . . . . . . . . . . . . . . .   7
     3.7.  Continuity Check Data . . . . . . . . . . . . . . . . . .   8
     3.8.  OAM data hierarchy  . . . . . . . . . . . . . . . . . . .   8
   4.  OAM YANG Module . . . . . . . . . . . . . . . . . . . . . . .  16
   5.  CL model applicability  . . . . . . . . . . . . . . . . . . .  43
     5.1.  BFD Extension . . . . . . . . . . . . . . . . . . . . . .  44
       5.1.1.  technology type extension . . . . . . . . . . . . . .  44
       5.1.2.  test point attributes extension . . . . . . . . . . .  44
     5.2.  LSP ping extension  . . . . . . . . . . . . . . . . . . .  46
       5.2.1.  technology type extension . . . . . . . . . . . . . .  47
       5.2.2.  test point attributes extension . . . . . . . . . . .  47
   6.  Security Considerations . . . . . . . . . . . . . . . . . . .  48
   7.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .  48
   8.  Normative References  . . . . . . . . . . . . . . . . . . . .  49
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  49

1.  Introduction

   Operations, Administration, and Maintenance (OAM) are important
   networking functions that allow operators to:

   1.  Monitor networks connections (Reachability Verification,
       Continuity Check).

   2.  Troubleshoot failures (Fault verification and localization).




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   3.  Monitor Performance

   An overview of OAM tools is presented at [RFC7276].

   Ping and Traceroute [RFC792], [RFC4443] are well-known fault
   verification and isolation tools, respectively, for IP networks.
   Over the years, different technologies have developed similar tools
   for similar purposes.

   In this document, we presents a base YANG Data model for
   connectionless OAM protocols.  The generic YANG model for
   connectionless OAM only includes configuration data and state data.
   It can be used in conjunction with data retrieval method model[lime
   retrieval methods], which focuses on data retrival procedures like
   RPC.  However it also can be used independently of data retrieval
   method model.

2.  Conventions used in this document

   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 [RFC2119].

   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 [RFC6020] and are not redefined
   here:

   o  augment

   o  data model

   o  data node

   The terminology for describing YANG data models is found in
   [RFC6020].






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2.1.  Terminology

   TP - Test Point

   MAC - Media Access Control

   BFD - Bidirectional Forwarding Detection

   RPC - A Remote Procedure Call, as used within the NETCONF protocol

2.2.  Tree Diagrams

   A simplified graphical representation of the data model is used in
   this document.  The meaning of the symbols in these diagrams is as
   follows:

   Each node is printed as:

   <status> <flags> <name> <opts> <type>

   <status> is one of:
        +  for current
        x  for deprecated
        o  for obsolete


   <flags> is one of:

       rw for configuration data
       ro for non-configuration data
       -x for rpcs
       -n for notifications


   <name> is the name of the node

   If the node is augmented into the tree from another module, its name
   is printed as <prefix>:<name>.

   <opts> is one of:

        ?  for an optional leaf or choice
        !  for a presence container
        *  for a leaf-list or list
        [<keys>] for a list's keys

   <type> is the name of the type for leafs and leaf-lists




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3.  Overview of the Connectionless OAM Model

   At the top of the Model, there is an oper container for session
   statistics.  Grouping is also defined for common session statistics
   and these are applicable for proactive OAM sessions.  Multiple test-
   point-locations keyed using technology specific keys (eg., IPv4
   address for IPv4 locations) are possible by augmented network nodes
   which are defined in [I-D.draft-ietf-i2rs-yang-network-topo] to
   describe the network hierarchies and the inventory of nodes contained
   in a network.  Each test-point-location is chosen based on location-
   type which when chosen, leads to a container that includes a list of
   test-point-locations keyed by technology specific keys.  Each test
   point location includes a test-point-location-info.  The test-point-
   location-info includes tp-technology, tp-tools, and connectionless-
   oam-layers.  The groupings of tp-address and tp-address-vrf are kept
   out of test-point-location-info to make it addressing agnostic and
   allow varied composition.  Depending upon the choice of the location-
   type (determined by the tp-address-vrf), the containers differ in its
   composition of test-point-locations while the test-point-location-
   info, is a common aspect of every test-point-location.  The vrf is
   used to describe the corresponding network instance.  The tp-
   technology indicate oam technology details.  The tp-tools describe
   the oam tools supported.  The connectionless-oam- layers is used to
   describe the relationship of one test point with other test points.
   The level in oam-layers indicate whether related oam test point is
   client layer, server layer or same layer.  The Model is augmented to
   /nd:networks/nd:network/nd:node using Test Point Locations defined
   below.

3.1.  TP Address

   In connectionless OAM, the tp address is defined with the following
   type:

   o  MAC address

   o  IPv4 or IPv6 address

   o  a pair of source, destination addresses, and interface (Useful for
      BFD)

   o  FEC

   o  System-id to represent the device or node.







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3.2.  Tools

   In connectionless OAM, the tools attribute is used to describe a
   toolset for fault detection and isolation, and for performance
   measurement.  And it can serve as a constraint condition when the
   base model be extended to specific OAM technology.  For example, to
   fulfill the icmp ping configuration, the "../coam:tools-ip/
   coam:rfc792" should be set to "true", and then the lime base model
   should be augmented with icmp ping specific details.

3.3.  OAM-layers

   As typical networks have a multi-layer architecture, the set of OAM
   protocols similarly take a multi-layer structure; each layer has its
   own OAM protocols [RFC7276] and is corresponding to specific network
   portion or pathand has associated test points.  OAM-layers is
   referred to a list of upper layer, lower layer that are related to
   current test point.  This allow users to easily navigate up and down
   to efficiently troubleshoot a connectivity issue at different layer.
   In this model, we have kept level default as 0, when all test points
   are located at the same layer.  Level is provided for scenarios where
   it might be possible to define layering relationship as it can be
   used to stitching fault at related oam layers.  For example, there is
   a network in which data traffic between two customer edges is
   transported over three consecutive network portions, the current test
   point is located in the second network portion.  If there is a defect
   in the first network portion is located at the upstream of the second
   network portion, the level of the first network portion is set to
   "-1".  If the third network portion is located at the downstream of
   the second network portion and the level is set to "1".  In another
   case, if the first network portion and the third network portion is
   in the same level of thesecond network portion, the level is set to
   "0".  The snippet below depicts an example of OAM layers.


















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                list oam-layers {
                  key "index";
                  leaf index {
                     type uint16 {
                        range "0..65535";
                     }
                  }
                  leaf level {
                      type int32 {
                           range "-1..1";
                      }
                      description
                        "Level";
                  }
                  ordered-by user;
                  description
                     "list of related oam layers.";
                }

3.4.  Test Point Locations Information

   This is a generic grouping for Test Point Locations Information.  It
   Provide details of Test Point Location using Tools, OAM-Layers
   grouping defined above.

3.5.  Test Point Locations

   This is a generic grouping for Test Point Locations.  Choice
   statement is used to define locations types, for example ipv4-
   location-type, ipv6-location-type, etc.  Container is defined under
   each location type containing list keyed to test point address, Test
   Point Location Information defined in section above, and routing
   instance vrf name if required.

3.6.  Path Discovery Data

   This is a generic grouping for path discovery data model that can be
   retrieved by any data retrieval methods including RPCs.  Path
   discovery data output from methods, includes src-test-point, dst-
   test-point, sequence-number, hop-cnt, session statistics of various
   kinds,path verification and path trace related information.  Path
   discovery includes data to be retrieved on a per-hop basis via a list
   of path-trace-info-list which includes information like timestamps,
   ingress-interface, egress-interface and app-meta-data.  The path
   discovery data model is made generic enough to allow active, passive
   and hybrid OAMs to do the retrieval.  None of the fields are made
   mandatory for that reason.  Noted that the retrieval methods are
   defined in [lime retrieval methods].



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3.7.  Continuity Check Data

   This is a generic grouping for continuity check data model that can
   be retrieved by any data retrieval methods including RPCs.
   Continuity check data output from methods, includes src-test-point,
   dst-test-point, sequence-number, hop-cnt and session statistics of
   various kinds.  The continuity check data model is made generic
   enough to allow active, passive and hybrid OAMs to do the retrieval.
   None of the fields are made mandatory for that reason.  Noted that
   the retrieval methods are defined in [lime retrieval methods].

3.8.  OAM data hierarchy

   The complete data hierarchy related to the OAM YANG model is
   presented below.

module: ietf-connectionless-oam
   +--ro oper {continuity-check}?
      +--ro cc-ipv4-sessions-statistics
      |  +--ro cc-session-statistics
      |     +--ro session-count?              uint32
      |     +--ro session-up-count?           uint32
      |     +--ro session-down-count?         uint32
      |     +--ro session-admin-down-count?   uint32
      +--ro cc-ipv6-sessions-statistics
         +--ro cc-session-statistics
            +--ro session-count?              uint32
            +--ro session-up-count?           uint32
            +--ro session-down-count?         uint32
            +--ro session-admin-down-count?   uint32
augment /nd:networks/nd:network/nd:node:
   +--rw tp-address-type-value?                       identityref
   +--rw (location-type)?
      +--:(ipv4-location-type)
      |  +--rw test-point-ipv4-location-list
      |     +--rw test-point-locations* [ipv4-location]
      |        +--rw ipv4-location    inet:ipv4-address
      |        +--rw vrf?             routing-instance-ref
      |        +--rw (technology)?
      |        |  +--:(technology-null)
      |        |  |  +--rw tech-null?       empty
      |        |  +--:(technology-string)
      |        |     +--rw ipv4-icmp?       string
      |        +--ro (tools)?
      |        |  +--:(tools-empty)
      |        |  |  +--ro tools-null?      empty
      |        |  +--:(tools-ip)
      |        |  |  +--ro rfc792?          boolean



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      |        |  |  +--ro rfc4443?         boolean
      |        |  |  +--ro rfc4884?         boolean
      |        |  |  +--ro rfc5837?         boolean
      |        |  +--:(tools-bfd)
      |        |  |  +--ro rfc5881?         boolean
      |        |  |  +--ro rfc5883?         boolean
      |        |  |  +--ro rfc5884?         boolean
      |        |  |  +--ro rfc5885?         boolean
      |        |  +--:(tools-mpls)
      |        |  |  +--ro rfc4379?         boolean
      |        |  |  +--ro rfc4687?         boolean
      |        |  |  +--ro rfc4950?         boolean
      |        |  |  +--ro mpls-rfc5884?    boolean
      |        |  +--:(tools-pw)
      |        |     +--ro rfc5085?         boolean
      |        |     +--ro pw_rfc5885?      boolean
      |        |     +--ro rfc6423?         boolean
      |        |     +--ro rfc6310?         boolean
      |        |     +--ro rfc7023?         boolean
      |        +--rw oam-layers* [index]
      |           +--rw index    uint16
      |           +--rw level?   int32
      +--:(ipv6-location-type)
      |  +--rw test-point-ipv6-location-list
      |     +--rw test-point-locations* [ipv6-location]
      |        +--rw ipv6-location    inet:ipv6-address
      |        +--rw vrf?             routing-instance-ref
      |        +--rw (technology)?
      |        |  +--:(technology-null)
      |        |  |  +--rw tech-null?       empty
      |        |  +--:(technology-string)
      |        |     +--rw ipv4-icmp?       string
      |        +--ro (tools)?
      |        |  +--:(tools-empty)
      |        |  |  +--ro tools-null?      empty
      |        |  +--:(tools-ip)
      |        |  |  +--ro rfc792?          boolean
      |        |  |  +--ro rfc4443?         boolean
      |        |  |  +--ro rfc4884?         boolean
      |        |  |  +--ro rfc5837?         boolean
      |        |  +--:(tools-bfd)
      |        |  |  +--ro rfc5881?         boolean
      |        |  |  +--ro rfc5883?         boolean
      |        |  |  +--ro rfc5884?         boolean
      |        |  |  +--ro rfc5885?         boolean
      |        |  +--:(tools-mpls)
      |        |  |  +--ro rfc4379?         boolean
      |        |  |  +--ro rfc4687?         boolean



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      |        |  |  +--ro rfc4950?         boolean
      |        |  |  +--ro mpls-rfc5884?    boolean
      |        |  +--:(tools-pw)
      |        |     +--ro rfc5085?         boolean
      |        |     +--ro pw_rfc5885?      boolean
      |        |     +--ro rfc6423?         boolean
      |        |     +--ro rfc6310?         boolean
      |        |     +--ro rfc7023?         boolean
      |        +--rw oam-layers* [index]
      |           +--rw index    uint16
      |           +--rw level?   int32
      +--:(mac-location-type)
      |  +--rw test-point-mac-address-location-list
      |     +--rw test-point-locations* [mac-address-location]
      |        +--rw mac-address-location    yang:mac-address
      |        +--rw (technology)?
      |        |  +--:(technology-null)
      |        |  |  +--rw tech-null?              empty
      |        |  +--:(technology-string)
      |        |     +--rw ipv4-icmp?              string
      |        +--ro (tools)?
      |        |  +--:(tools-empty)
      |        |  |  +--ro tools-null?             empty
      |        |  +--:(tools-ip)
      |        |  |  +--ro rfc792?                 boolean
      |        |  |  +--ro rfc4443?                boolean
      |        |  |  +--ro rfc4884?                boolean
      |        |  |  +--ro rfc5837?                boolean
      |        |  +--:(tools-bfd)
      |        |  |  +--ro rfc5881?                boolean
      |        |  |  +--ro rfc5883?                boolean
      |        |  |  +--ro rfc5884?                boolean
      |        |  |  +--ro rfc5885?                boolean
      |        |  +--:(tools-mpls)
      |        |  |  +--ro rfc4379?                boolean
      |        |  |  +--ro rfc4687?                boolean
      |        |  |  +--ro rfc4950?                boolean
      |        |  |  +--ro mpls-rfc5884?           boolean
      |        |  +--:(tools-pw)
      |        |     +--ro rfc5085?                boolean
      |        |     +--ro pw_rfc5885?             boolean
      |        |     +--ro rfc6423?                boolean
      |        |     +--ro rfc6310?                boolean
      |        |     +--ro rfc7023?                boolean
      |        +--rw oam-layers* [index]
      |           +--rw index    uint16
      |           +--rw level?   int32
      +--:(tunnel-location-type)



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      |  +--rw test-point-tunnel-address-location-list
      |     +--rw test-point-locations* [tunnel-location]
      |        +--rw tunnel-location    uint32
      |        +--rw vrf?               routing-instance-ref
      |        +--rw (technology)?
      |        |  +--:(technology-null)
      |        |  |  +--rw tech-null?         empty
      |        |  +--:(technology-string)
      |        |     +--rw ipv4-icmp?         string
      |        +--ro (tools)?
      |        |  +--:(tools-empty)
      |        |  |  +--ro tools-null?        empty
      |        |  +--:(tools-ip)
      |        |  |  +--ro rfc792?            boolean
      |        |  |  +--ro rfc4443?           boolean
      |        |  |  +--ro rfc4884?           boolean
      |        |  |  +--ro rfc5837?           boolean
      |        |  +--:(tools-bfd)
      |        |  |  +--ro rfc5881?           boolean
      |        |  |  +--ro rfc5883?           boolean
      |        |  |  +--ro rfc5884?           boolean
      |        |  |  +--ro rfc5885?           boolean
      |        |  +--:(tools-mpls)
      |        |  |  +--ro rfc4379?           boolean
      |        |  |  +--ro rfc4687?           boolean
      |        |  |  +--ro rfc4950?           boolean
      |        |  |  +--ro mpls-rfc5884?      boolean
      |        |  +--:(tools-pw)
      |        |     +--ro rfc5085?           boolean
      |        |     +--ro pw_rfc5885?        boolean
      |        |     +--ro rfc6423?           boolean
      |        |     +--ro rfc6310?           boolean
      |        |     +--ro rfc7023?           boolean
      |        +--rw oam-layers* [index]
      |           +--rw index    uint16
      |           +--rw level?   int32
      +--:(ip-prefix-location-type)
      |  +--rw test-point-ip-prefix-location-list
      |     +--rw test-point-locations* [ip-prefix-location]
      |        +--rw ip-prefix-location    inet:ip-prefix
      |        +--rw vrf?                  routing-instance-ref
      |        +--rw (technology)?
      |        |  +--:(technology-null)
      |        |  |  +--rw tech-null?            empty
      |        |  +--:(technology-string)
      |        |     +--rw ipv4-icmp?            string
      |        +--ro (tools)?
      |        |  +--:(tools-empty)



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      |        |  |  +--ro tools-null?           empty
      |        |  +--:(tools-ip)
      |        |  |  +--ro rfc792?               boolean
      |        |  |  +--ro rfc4443?              boolean
      |        |  |  +--ro rfc4884?              boolean
      |        |  |  +--ro rfc5837?              boolean
      |        |  +--:(tools-bfd)
      |        |  |  +--ro rfc5881?              boolean
      |        |  |  +--ro rfc5883?              boolean
      |        |  |  +--ro rfc5884?              boolean
      |        |  |  +--ro rfc5885?              boolean
      |        |  +--:(tools-mpls)
      |        |  |  +--ro rfc4379?              boolean
      |        |  |  +--ro rfc4687?              boolean
      |        |  |  +--ro rfc4950?              boolean
      |        |  |  +--ro mpls-rfc5884?         boolean
      |        |  +--:(tools-pw)
      |        |     +--ro rfc5085?              boolean
      |        |     +--ro pw_rfc5885?           boolean
      |        |     +--ro rfc6423?              boolean
      |        |     +--ro rfc6310?              boolean
      |        |     +--ro rfc7023?              boolean
      |        +--rw oam-layers* [index]
      |           +--rw index    uint16
      |           +--rw level?   int32
      +--:(route-distinguisher-location-type)
      |  +--rw test-point-route-dist-location-list
      |     +--rw test-point-locations* [route-dist-location]
      |        +--rw route-dist-location    uint32
      |        +--rw vrf?                   routing-instance-ref
      |        +--rw (technology)?
      |        |  +--:(technology-null)
      |        |  |  +--rw tech-null?             empty
      |        |  +--:(technology-string)
      |        |     +--rw ipv4-icmp?             string
      |        +--ro (tools)?
      |        |  +--:(tools-empty)
      |        |  |  +--ro tools-null?            empty
      |        |  +--:(tools-ip)
      |        |  |  +--ro rfc792?                boolean
      |        |  |  +--ro rfc4443?               boolean
      |        |  |  +--ro rfc4884?               boolean
      |        |  |  +--ro rfc5837?               boolean
      |        |  +--:(tools-bfd)
      |        |  |  +--ro rfc5881?               boolean
      |        |  |  +--ro rfc5883?               boolean
      |        |  |  +--ro rfc5884?               boolean
      |        |  |  +--ro rfc5885?               boolean



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      |        |  +--:(tools-mpls)
      |        |  |  +--ro rfc4379?               boolean
      |        |  |  +--ro rfc4687?               boolean
      |        |  |  +--ro rfc4950?               boolean
      |        |  |  +--ro mpls-rfc5884?          boolean
      |        |  +--:(tools-pw)
      |        |     +--ro rfc5085?               boolean
      |        |     +--ro pw_rfc5885?            boolean
      |        |     +--ro rfc6423?               boolean
      |        |     +--ro rfc6310?               boolean
      |        |     +--ro rfc7023?               boolean
      |        +--rw oam-layers* [index]
      |           +--rw index    uint16
      |           +--rw level?   int32
      +--:(group-ip-address-location-type)
      |  +--rw test-point-group-ip-address-location-list
      |     +--rw test-point-locations* [group-ip-address-location]
      |        +--rw group-ip-address-location    IP-Multicast-Group-Address
      |        +--rw vrf?                         routing-instance-ref
      |        +--rw (technology)?
      |        |  +--:(technology-null)
      |        |  |  +--rw tech-null?                   empty
      |        |  +--:(technology-string)
      |        |     +--rw ipv4-icmp?                   string
      |        +--ro (tools)?
      |        |  +--:(tools-empty)
      |        |  |  +--ro tools-null?                  empty
      |        |  +--:(tools-ip)
      |        |  |  +--ro rfc792?                      boolean
      |        |  |  +--ro rfc4443?                     boolean
      |        |  |  +--ro rfc4884?                     boolean
      |        |  |  +--ro rfc5837?                     boolean
      |        |  +--:(tools-bfd)
      |        |  |  +--ro rfc5881?                     boolean
      |        |  |  +--ro rfc5883?                     boolean
      |        |  |  +--ro rfc5884?                     boolean
      |        |  |  +--ro rfc5885?                     boolean
      |        |  +--:(tools-mpls)
      |        |  |  +--ro rfc4379?                     boolean
      |        |  |  +--ro rfc4687?                     boolean
      |        |  |  +--ro rfc4950?                     boolean
      |        |  |  +--ro mpls-rfc5884?                boolean
      |        |  +--:(tools-pw)
      |        |     +--ro rfc5085?                     boolean
      |        |     +--ro pw_rfc5885?                  boolean
      |        |     +--ro rfc6423?                     boolean
      |        |     +--ro rfc6310?                     boolean
      |        |     +--ro rfc7023?                     boolean



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      |        +--rw oam-layers* [index]
      |           +--rw index    uint16
      |           +--rw level?   int32
      +--:(group-as-number-location-type)
      |  +--rw test-point-as-number-location-list
      |     +--rw test-point-locations* [as-number-location]
      |        +--rw as-number-location    inet:as-number
      |        +--rw vrf?                  routing-instance-ref
      |        +--rw (technology)?
      |        |  +--:(technology-null)
      |        |  |  +--rw tech-null?            empty
      |        |  +--:(technology-string)
      |        |     +--rw ipv4-icmp?            string
      |        +--ro (tools)?
      |        |  +--:(tools-empty)
      |        |  |  +--ro tools-null?           empty
      |        |  +--:(tools-ip)
      |        |  |  +--ro rfc792?               boolean
      |        |  |  +--ro rfc4443?              boolean
      |        |  |  +--ro rfc4884?              boolean
      |        |  |  +--ro rfc5837?              boolean
      |        |  +--:(tools-bfd)
      |        |  |  +--ro rfc5881?              boolean
      |        |  |  +--ro rfc5883?              boolean
      |        |  |  +--ro rfc5884?              boolean
      |        |  |  +--ro rfc5885?              boolean
      |        |  +--:(tools-mpls)
      |        |  |  +--ro rfc4379?              boolean
      |        |  |  +--ro rfc4687?              boolean
      |        |  |  +--ro rfc4950?              boolean
      |        |  |  +--ro mpls-rfc5884?         boolean
      |        |  +--:(tools-pw)
      |        |     +--ro rfc5085?              boolean
      |        |     +--ro pw_rfc5885?           boolean
      |        |     +--ro rfc6423?              boolean
      |        |     +--ro rfc6310?              boolean
      |        |     +--ro rfc7023?              boolean
      |        +--rw oam-layers* [index]
      |           +--rw index    uint16
      |           +--rw level?   int32
      +--:(group-lsp-id-location-type)
      |  +--rw test-point-lsp-id-location-list
      |     +--rw test-point-locations* [lsp-id-location]
      |        +--rw lsp-id-location    string
      |        +--rw vrf?               routing-instance-ref
      |        +--rw (technology)?
      |        |  +--:(technology-null)
      |        |  |  +--rw tech-null?         empty



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      |        |  +--:(technology-string)
      |        |     +--rw ipv4-icmp?         string
      |        +--ro (tools)?
      |        |  +--:(tools-empty)
      |        |  |  +--ro tools-null?        empty
      |        |  +--:(tools-ip)
      |        |  |  +--ro rfc792?            boolean
      |        |  |  +--ro rfc4443?           boolean
      |        |  |  +--ro rfc4884?           boolean
      |        |  |  +--ro rfc5837?           boolean
      |        |  +--:(tools-bfd)
      |        |  |  +--ro rfc5881?           boolean
      |        |  |  +--ro rfc5883?           boolean
      |        |  |  +--ro rfc5884?           boolean
      |        |  |  +--ro rfc5885?           boolean
      |        |  +--:(tools-mpls)
      |        |  |  +--ro rfc4379?           boolean
      |        |  |  +--ro rfc4687?           boolean
      |        |  |  +--ro rfc4950?           boolean
      |        |  |  +--ro mpls-rfc5884?      boolean
      |        |  +--:(tools-pw)
      |        |     +--ro rfc5085?           boolean
      |        |     +--ro pw_rfc5885?        boolean
      |        |     +--ro rfc6423?           boolean
      |        |     +--ro rfc6310?           boolean
      |        |     +--ro rfc7023?           boolean
      |        +--rw oam-layers* [index]
      |           +--rw index    uint16
      |           +--rw level?   int32
      +--:(group-system-id-location-type)
         +--rw test-point-system-info-location-list
            +--rw test-point-locations* [system-id-location]
               +--rw system-id-location    inet:uri
               +--rw vrf?                  routing-instance-ref
               +--rw (technology)?
               |  +--:(technology-null)
               |  |  +--rw tech-null?            empty
               |  +--:(technology-string)
               |     +--rw ipv4-icmp?            string
               +--ro (tools)?
               |  +--:(tools-empty)
               |  |  +--ro tools-null?           empty
               |  +--:(tools-ip)
               |  |  +--ro rfc792?               boolean
               |  |  +--ro rfc4443?              boolean
               |  |  +--ro rfc4884?              boolean
               |  |  +--ro rfc5837?              boolean
               |  +--:(tools-bfd)



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               |  |  +--ro rfc5881?              boolean
               |  |  +--ro rfc5883?              boolean
               |  |  +--ro rfc5884?              boolean
               |  |  +--ro rfc5885?              boolean
               |  +--:(tools-mpls)
               |  |  +--ro rfc4379?              boolean
               |  |  +--ro rfc4687?              boolean
               |  |  +--ro rfc4950?              boolean
               |  |  +--ro mpls-rfc5884?         boolean
               |  +--:(tools-pw)
               |     +--ro rfc5085?              boolean
               |     +--ro pw_rfc5885?           boolean
               |     +--ro rfc6423?              boolean
               |     +--ro rfc6310?              boolean
               |     +--ro rfc7023?              boolean
               +--rw oam-layers* [index]
                  +--rw index    uint16
                  +--rw level?   int32


                           data hierarchy of OAM

4.  OAM YANG Module

   <CODE BEGINS> file "ietf-connectionless-oam.yang"

module ietf-connectionless-oam {
    namespace "urn:ietf:params:xml:ns:yang:ietf-connectionless-oam";
    prefix coam;

    import ietf-network{
      prefix nd;
    }
    import ietf-yang-types {
      prefix yang;
    }
    import ietf-interfaces {
      prefix if;
    }
    import ietf-inet-types {
      prefix inet;
    }
    import ietf-network-instance {
      prefix "ni";
    }

    organization "IETF LIME Working Group";
    contact



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        "Deepak Kumar dekumar@cisco.com
         Qin Wu       bill.wu@huawei.com
         S Raghavan   srihari@cisco.com
         Zitao Wang   wangzitao@huawei.com
         R Rahman     rrahman@cisco.com";

    description

      "This YANG module defines the generic configuration,
       data model, statistics for connectionless OAM to be
       used within IETF in a protocol indpendent manner.
       Functional level abstraction is indendent with
       YANG modeling. It is assumed that each protocol maps
       corresponding abstracts to its native format.
       Each protocol may extend the YANG model defined
       here to include protocol specific extensions";
    revision 2016-10-31 {
      description
        "Initial revision. - 07 version";
      reference "";
    }
    /* features */
    feature connection-less {
      description
        "this feature indicates that OAM solution is connection less.";
    }
    feature continuity-check {
      description
        "This feature indicates that the server supports
         executing continuity check OAM command and
         returning a response. Servers that do not advertise
         this feature will not support executing
         continuity check command or rpc model for
         continuity check command.";
    }
    feature path-discovery {
        description
        "This feature indicates that the server supports
         executing path discovery OAM command and
         returning a response. Servers that do not advertise
         this feature will not support executing
         path discovery command or rpc model for
         path discovery command.";
    }

    /* Identities */
    /* typedefs */
      typedef routing-instance-ref {



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        type leafref {
          path "/ni:network-instances/ni:network-instance/ni:name";
        }
        description
        "This type is used for leafs that reference a routing instance
         configuration.";
      }

       typedef IPv4-Multicast-Group-Address {
            type string {
             pattern '(2((2[4-9])|(3[0-9]))\.)'
                         +'(([0-9]|[1-9][0-9]|1[0-9][0-9]|'
                         +'2[0-4][0-9]|25[0-5])\.){2}'
                         +'([0-9]|[1-9][0-9]|1[0-9][0-9]'
                         +'|2[0-4][0-9]|25[0-5])';
            }
            description
              "The IPv4-Multicast-Group-Address type
               represents an IPv4 multicast address
               in dotted-quad notation.";
            reference "RFC4607";
      } // typedef IPv4-Multicast-Group-Address
      typedef IPv6-Multicast-Group-Address {
            type string {
            pattern
                        '(((FF|ff)[0-9a-fA-F]{2}):)([0-9a-fA-F]'
                        +'{0,4}:){0,5}((([0-9a-fA-F]{0,4}:)?'
                        +'(:|[0-9a-fA-F]{0,4}))|(((25[0-5]|2[0-4]'
                        +'[0-9]|[01]?[0-9]?[0-9])\.){3}(25[0-5]|'
                        +'2[0-4][0-9]|[01]?[0-9]?[0-9])))';
            pattern
            '(([^:]+:){6}(([^:]+:[^:]+)|'
                        +'(.*\..*)))|((([^:]+:)*[^:]+)'
                        +'?::(([^:]+:)*[^:]+)?)';
             }
            description
                        "The IPv6-Multicast-Group-Address
                        type represents an IPv6 address in full,
                        mixed, shortened, and shortened-mixed
                        notation.";
            reference "RFC4291 2.7.
            ietf-inet-types:ipv6-address";
      }
      typedef IP-Multicast-Group-Address {
            type union {
              type IPv4-Multicast-Group-Address;
              type IPv6-Multicast-Group-Address;
            }



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            description
             "The IP-Multicast-Group-Address type
              represents an IP multicast address and
              is IP version neutral. The format of the
              textual representations implies the IP version.";
      } // typedef IP-Multicast-Group-Address

    identity fec-types {

      description
      "This is base identity of fec types which are ip-prefix,
       bgp, tunnel, pwe3, vpls, etc.";
    }

    typedef fec-type {
      type identityref {
        base fec-types;
      }
      description "Target FEC type.";
    }

    typedef oam-counter32 {
      type yang:zero-based-counter32;
      description
        "defines 32 bit counter for OAM";
    }

    identity time-resolution{
      description
        "Time interval resolution";
    } //base identity

    identity hours {
      base time-resolution;
      description
        "Hours";
    }

    identity minutes {
      base time-resolution;
      description
        "Minutes";
    }

    identity seconds {
      base time-resolution;
      description
        "Seconds";



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    }

    identity milliseconds {
      base time-resolution;
      description
        "Milliseconds";
    }

    identity microseconds {

      base time-resolution;
      description
        "Microseconds";
    }

    identity nanoseconds {
      base time-resolution;
      description
        "Nanoseconds";
    }

    /* groupings */
    grouping cc-session-statsitics {
      description "Grouping for session statistics.";
      container cc-session-statistics {
        description "cc session counters";
        leaf session-count {
           type uint32;
           description "Number of cc sessions.";
        }
        leaf session-up-count {
           type uint32;
           description "Number of sessions which are up.";
        }
        leaf session-down-count {
           type uint32;
           description "Number of sessions which are down.";
        }
        leaf session-admin-down-count {
           type uint32;
           description "Number of sessions which are admin-down.";
        }
      }
    }

    grouping session-packet-statistics {
      description "Grouping for per session packet statistics";
      container session-packet-statistics {



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        description "Per session packet statistics.";
        leaf rx-packet-count {
          type uint32;
          description "Total received packet count.";
        }
        leaf tx-packet-count {
          type uint32;
          description "Total transmitted packet count.";
        }
        leaf rx-bad-packet {

          type uint32;
          description "Total received bad packet.";
        }
        leaf tx-packet-failed {
          type uint32;
          description "Total send packet failed.";
        }
      }
    }

    grouping cc-per-session-statistics {
      description "Grouping for per session statistics";
      container cc-per-session-statistics {
        description "per session statistics.";
        leaf create-time {
          type yang:date-and-time;
          description "Time and date when session is created.";
        }
        leaf last-down-time {
          type yang:date-and-time;
          description "Time and date last time session is down.";
        }
        leaf last-up-time {
          type yang:date-and-time;
          description "Time and date last time session is up.";
        }
        leaf down-count {
          type uint32;
          description "Total down count.";
        }
        leaf admin-down-count {
          type uint32;
          description "Total down count.";
        }

        uses session-packet-statistics;
      }



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    }

    grouping session-error-statistics {
      description "Grouping for per session error statistics";
      container session-error-statistics {
        description "Per session error statistics.";
        leaf packet-drops-count {
          type uint32;
          description "Total received packet drops count.";
        }
        leaf packet-reorder-count {

          type uint32;
          description "Total received packet reordered count.";
        }
        leaf packets-out-of-seq-count {
          type uint32;
          description "Total received out of sequence count.";
        }
        leaf packets-dup-count {
          type uint32;
          description "Total received packet duplicates count.";
        }
      }
    }

    grouping session-delay-statistics {
      description "Grouping for per session delay statistics";
      container session-delay-statistics {
        description "Session delay summarised information.";
        leaf time-resolution-value {
          type identityref {
            base time-resolution;
          }
          description "Time units among choice of s,ms,ns etc.";
        }
        leaf min-delay-value {
          type uint32;
          description "Minimum delay value observed.";
        }
        leaf max-delay-value {
          type uint32;
          description "Maximum delay value observed.";
        }
        leaf average-delay-value {
          type uint32;
          description "Average delay value observed.";
        }



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      }
    }

    grouping session-jitter-statistics {
      description "Grouping for per session jitter statistics";
      container session-jitter-statistics {
        description "Session jitter summarised information.";
        leaf time-resolution-value {
          type identityref {
            base time-resolution;
          }
          description "Time units among choice of s,ms,ns etc.";

        }
        leaf min-jitter-value {
          type uint32;
          description "Minimum jitter value observed.";
        }
        leaf max-jitter-value {
          type uint32;
          description "Maximum jitter value observed.";
        }
        leaf average-jitter-value {
          type uint32;
          description "Average jitter value observed.";
        }
      }
    }

    grouping session-path-verification-statistics {
      description "Grouping for per session path verification statistics";
      container session-path-verification-statistics{
        description "OAM per session path verification statistics.";
        leaf verified-count {
          type uint32;
          description "Total number of packets that went through a path as intended.";
        }
        leaf failed-count {
          type uint32;
          description "Total number of packets that went through an unintended path.";
        }
      }
    }

    grouping session-type {
      description
        "This object indicates the current session
         definition.";



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      leaf session-type-enum {
        type enumeration {
          enum proactive {
            description
              "The current session is proactive";
          }
          enum on-demand {
            description
              "The current session is on-demand.";
          }
        }
        default "on-demand";
        description

          "session type enum";
      }
    }

    identity tp-address-type {
      description
        "Test point address type";
    } //base identity

    identity mac-address-type {
      base tp-address-type;
      description
        "MAC address type";
    }

    identity ipv4-address-type {
      base tp-address-type;
      description
        "IPv4 address type";
    }

    identity ipv6-address-type {
      base tp-address-type;
      description
        "IPv6 address type";
    }

    identity src-dst-address-type {
      base tp-address-type;
      description
        "Source/Dest address type";
    }

    identity fec-address-type {



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      base tp-address-type;
      description
        "FEC address type";
    }

    identity tlv-address-type {
      base tp-address-type;
      description
        "TLV address type";
    }

    identity system-id-address-type {
      base tp-address-type;
      description

        "System id address type";
    }

    identity lsp-id-address-type {
      base tp-address-type;
      description
        "LSP ID address type";
    }

    identity as-number-address-type {
      base tp-address-type;
      description
        "AS number address type";
    }

    identity group-ip-address-type {
      base tp-address-type;
      description
        "Group IP address type";
    }

    identity route-distinguisher-address-type {
      base tp-address-type;
      description
        "Route Distinguisher address type";
    }

    identity ip-prefix-address-type {
      base tp-address-type;
      description
        "IP prefix address type";
    }




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    identity tunnel-address-type {
      base tp-address-type;
      description
        "Tunnel address type";
    }

    grouping tp-address {
      leaf tp-address-type-value {
        type identityref {
          base tp-address-type;
        }
        description "Test point address type.";
      }

      choice tp-address {

        case mac-address {
          when "'tp-address-type-value' = 'mac-address-type'" {
            description "MAC address type";
          }
          leaf mac-address {
            type yang:mac-address;
            description
            "MAC Address";
          }
          description
          "MAC Address based MP Addressing.";
        }
        case ipv4-address {
          when "'tp-address-type-value' = 'ipv4-address-type'" {
            description "IPv4 address type";
          }
          leaf ipv4-address {
            type inet:ipv4-address;
            description
            "Ipv4 Address";
          }
          description
          "Ip Address based MP Addressing.";
        }
        case ipv6-address {
          when "'tp-address-type-value' = 'ipv6-address-type'" {
            description "IPv6 address type";
          }
          leaf ipv6-address {
            type inet:ipv6-address;
            description
            "Ipv6 Address";



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          }
          description
          "ipv6 Address based MP Addressing.";
        }
        case src-dst-address {
          when "'tp-address-type-value' = 'src-dst-address-type'" {
            description "Src dest address type for BFD";
          }
          leaf src-ip-address {
            type inet:ip-address;
                    description
                    "source ip address.";
          }
          leaf dst-ip-address {
            type inet:ip-address;
                    description

                    "destination ip address.";
          }
          leaf Interface {
            type if:interface-ref;
                    description
                    "interface.";
          }
        }
        case fec {
          when "'tp-address-type-value' = 'fec-address-type'" {
            description "FEC address type";
          }
          leaf fec-type {
            type fec-type;
                    description
                    "fec type.";
          }
          choice fec-value {
                   description
                   "fec value.";
            case ip-prefix {
              leaf ip-prefix {
                type inet:ip-prefix;
                            description
                            "ip prefix.";
              }
            }
            case bgp {
              leaf bgp {
                type inet:ip-prefix;
                            description



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                            "BGP Labeled Prefix ";
              }
            }
            case tunnel {
              leaf tunnel-interface {
                type uint32;
                            description
                            "VPN Prefix ";
              }
            }

            case pw {
              leaf remote-pe-address{
               type inet:ip-address;
                           description
                           "remote pe address.";
              }
              leaf pw-id {
                type uint32;
                            description
                            "Pseudowire id.";
              }
            }
            case vpls {
              leaf route-distinguisher {
                type uint32;
                            description
                            "Route Distinguisher(8 octets).";
              }
              leaf sender-ve-id{
               type uint32;
                           description
                           "Sender's VE ID.";
              }
              leaf receiver-ve-id{
               type uint32;
                           description
                           "Receiver's VE ID.";
              }
            }
            case mpls-mldp{
             choice root-address{
                      description
                          "root address choice.";
              case ip-address{
               leaf source-address{
                type inet:ip-address;
                            description



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                            "ip address.";
               }
               leaf group-ip-address{
                type IP-Multicast-Group-Address;
                            description
                            "group ip address.";
               }
              }
              case vpn{
               leaf as-number{
                type inet:as-number;

                            description
                            "AS number.";
               }
              }
              case global-id{
               leaf lsp-id{
                type string;
                            description
                            "lsp id.";
               }
              }
             }
            }
          }
        }
        case tlv-address {
          when "'tp-address-type-value' = 'tlv-address-type'" {
            description "TLV address type";
          }
           leaf tlv-type {
             type int16;
             description
               "Type of MEP-ID";
           }
           leaf tlv-len {
             type int16;
             description
               "Length of MEP-ID value";
           }
           leaf tlv-value {
             type binary {
               length "12..255";
           }
           description
             "Value please refer RFC6428 (Figure 4,5,6).";
           }



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        description
          "MEP-ID";
        }
        case system-info {
          when "'tp-address-type-value' = 'system-id-address-type'" {
            description "System id address type";
          }
          leaf system-id {
            type inet:uri;
            description
              "System ID assigned to this node.";
          }

        }
        description
          "TP Addressing.";
      }
      description
        "TP Address";
    }

    grouping tp-address-vrf {
      description
        "Test point address with VRF.";
      leaf vrf {
        type routing-instance-ref;
            description
            "The vrf is used to describe the
             corresponding network instance";
      }

      uses tp-address;
    }

    grouping connectionless-oam-layers {
      list oam-layers {
         key "index";
         leaf index {
             type uint16 {
                  range "0..65535";
             }
             description
               "Index";
         }
        leaf level {
            type int32 {
                 range "-1..1";
            }



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            default 0;
            description
              "Level 0 indicates default level, -1 means server
               and +1 means client layer.
               In relationship 0 means same layer.";
        }
        ordered-by user;
         description
            "list of related oam layers.
             0 means they are in same level, especially
             interworking scenarios of stiching multiple
             technology at same layer.
             -1 means server layer, for eg:- in case of

             Overlay and Underlay, Underlay is server layer for
             Overlay Test Point.
             +1 means client layer, for eg:- in case of
             Service OAM and Transport OAM, Service OAM is client
             layer to Transport OAM.";
      }
      description
        "connectionless related OAM layer";
    }

    grouping tp-technology {
       choice technology {
          default technology-null;
          case technology-null {
            description
              "this is a placeholder when no technology is needed.";
            leaf tech-null {
               type empty;
               description
                 "there is no technology define";
            }
          }
          description
            "technology choice null";
          case technology-string {
            description
            "oam technology string";
            leaf ipv4-icmp {
              type string;
              description
                "name to identify oam technology";
            }
         }
       }



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       description
        "OAM Technology";
    }

    grouping tp-tools {
      description
        "Test Point OAM Toolset.";
      choice tools {
           default tools-empty;
                   config false;
           description
           "choice of test point tools.
            Empty tools means based on Test Point it's implicit
            all OAM tools are present and no further configuration
            is supported.";

        case tools-empty {
          description
            "this is a placeholder when oam toolset is not needed.";
          leaf tools-null {
            type empty;
            description
              "there is no oam toolset defined.";
          }
        }
        case tools-ip{
          description
            "Oam Toolset for Ip";
          leaf rfc792 {
            type boolean;
            description
              "rfc792 (icmpv4) supported.";
          }
          leaf rfc4443 {
            type boolean;
            description
              "rfc4443 supported.";
          }
          leaf rfc4884 {
            type boolean;
                    description
                    "rfc4884 supported.";
          }
          leaf rfc5837 {
            type boolean;
                    description
                    "rfc5837 supported.";
          }



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        }
        case tools-bfd {
          leaf rfc5881 {
            type boolean;
                    description
                    "rfc5881 supported.";
          }
          leaf rfc5883 {
            type boolean;
                    description
                    "rfc5883 supported.";
          }
          leaf rfc5884 {
            type boolean;
                    description

                    "rfc5884 supported.";
          }
          leaf rfc5885 {
            type boolean;
                    description
                    "rfc5885 supported.";
          }
        }
        case tools-mpls {
          description
            "Oam Toolset for mpls";
          leaf rfc4379 {
            type boolean;
                    description
                    "rfc4379 supported.";
          }
          leaf rfc4687 {
            type boolean;
                    description
                    "rfc4687 supported.";
          }
          leaf rfc4950 {
            type boolean;
                    description
                    "rfc4950 supported.";
          }
          leaf mpls-rfc5884 {
            type boolean;
                    description
                    "rfc5884 supported.";
          }
        }



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        case tools-pw {
          description
            "Oam Toolset for pw oam.";
          leaf rfc5085 {
            type boolean;
                    description
                    "rfc5085 supported.";
          }
          leaf pw_rfc5885 {
            type boolean;
                    description
                    "rfc5885 supported.";
          }
          leaf rfc6423 {
            type boolean;
                    description
                    "rfc6423 supported.";
          }
          leaf rfc6310 {
            type boolean;
                    description
                    "rfc6310 supported.";
          }
          leaf rfc7023 {
            type boolean;
                    description
                    "rfc7023 supported.";
          }
        }
      }
    }

    grouping test-point-location-info {
      uses tp-technology;
      uses tp-tools;
      uses connectionless-oam-layers;
      description
        "Test point Location";
    }

    grouping test-point-locations {
      description "Group of test point locations.";
      leaf tp-address-type-value {

        type identityref {
          base tp-address-type;
        }
        description "Test point address type.";



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      }
      choice location-type {
        case ipv4-location-type {
          when "'tp-address-type-value' = 'ipv4-address-type'" {
          description
            "when test point address is equal to ipv4 address.";
          }
          container test-point-ipv4-location-list {
            list test-point-locations {
              key "ipv4-location";
              leaf ipv4-location {
                type inet:ipv4-address;
                description
                  "Ipv4 Address.";
              }
              leaf vrf {
                type routing-instance-ref;
                    description
                    "The vrf is used to describe the
                     corresponding network instance";
              }
              uses test-point-location-info;
              ordered-by user;
              description
                "list of test point locations.";
            }
            description
              "Serves as top-level container for test point location list.";
          }
        }
        case ipv6-location-type {
          when "'tp-address-type-value' = 'ipv6-address-type'" {
          description
            "when test point address is equal to ipv6 address";
          }
          container test-point-ipv6-location-list {
            list test-point-locations {
              key "ipv6-location";
              leaf ipv6-location {
                type inet:ipv6-address;
                description
                  "Ipv6 Address.";
              }
              leaf vrf {

                type routing-instance-ref;
                    description
                    "The vrf is used to describe the



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                     corresponding network instance";
              }
              uses test-point-location-info;
              ordered-by user;
              description
                "list of test point locations.";
            }
            description
              "Serves as top-level container for test point location list.";
          }
        }
        case mac-location-type {
          when "'tp-address-type-value' = 'mac-address-type'" {
            description
              "when test point address is equal to mac address.";
          }
          container test-point-mac-address-location-list {
            list test-point-locations {
            key "mac-address-location";
            leaf mac-address-location {
              type yang:mac-address;
              description
                "MAC Address";
            }
            uses test-point-location-info;
            ordered-by user;
            description
             "list of test point locations.";
            }
            description
              "Serves as top-level container for test point location list.";
          }
        }
        case tunnel-location-type {
          when "'tp-address-type-value' = 'tunnel-address-type'" {
            description
              "when test point address is equal to tunnel type.";
          }
          container test-point-tunnel-address-location-list {
            list test-point-locations {
            key "tunnel-location";
            leaf tunnel-location {
              type uint32;
              description
                "VPN Prefix";

            }
            leaf vrf {



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              type routing-instance-ref;
                  description
                  "The vrf is used to describe the
                   corresponding network instance";
            }
            uses test-point-location-info;
            ordered-by user;
            description
             "list of test point locations.";
            }
            description
              "Serves as top-level container for test point location list.";
          }
        }
        case ip-prefix-location-type {
          when "'tp-address-type-value' = 'ip-prefix-address-type'" {
            description
              "when test point address is equal to ip prefix.";
          }
          container test-point-ip-prefix-location-list {
            list test-point-locations {
            key "ip-prefix-location";
            leaf ip-prefix-location {
              type inet:ip-prefix;
              description
                "IP Prefix";
            }
            leaf vrf {
              type routing-instance-ref;
                  description
                  "The vrf is used to describe the
                   corresponding network instance";
            }
            uses test-point-location-info;
            ordered-by user;
            description
             "list of test point locations.";
            }
            description
              "Serves as top-level container for test point location list.";
          }
        }
        case route-distinguisher-location-type {
          when "'tp-address-type-value' = 'route-distinguisher-address-type'" {
            description "when test point address is equal to
            route distinguiher.";

          }



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          container test-point-route-dist-location-list {
            list test-point-locations {
            key "route-dist-location";
            leaf route-dist-location {
              type uint32;
              description
                "Route Distinguisher(8 octets).";
            }
            leaf vrf {
              type routing-instance-ref;
                  description
                  "The vrf is used to describe the
                   corresponding network instance";
            }
            uses test-point-location-info;
            ordered-by user;
            description
             "list of test point locations.";
            }
            description
              "Serves as top-level container for test point location list.";
          }
        }
        case group-ip-address-location-type {
          when "'tp-address-type-value' = 'group-ip-address-type'" {
            description "when test point address is equal to
                         group ip address.";
          }
          container test-point-group-ip-address-location-list {
            list test-point-locations {
            key "group-ip-address-location";
            leaf group-ip-address-location {
              type IP-Multicast-Group-Address;
              description
                "Group IP address.";
            }
            leaf vrf {
              type routing-instance-ref;
                  description
                  "The vrf is used to describe the
                   corresponding network instance";
            }
            uses test-point-location-info;
            ordered-by user;
            description
             "list of test point locations.";
            }




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            description
              "Serves as top-level container for test point location list.";
          }
        }
        case group-as-number-location-type {
          when "'tp-address-type-value' = 'as-number-address-type'" {
            description "when test point address is equal to
                         as-number.";
          }
          container test-point-as-number-location-list {
            list test-point-locations {
            key "as-number-location";
            leaf as-number-location {
              type inet:as-number;
              description
                "AS number.";
            }
            leaf vrf {
              type routing-instance-ref;
                  description
                  "The vrf is used to describe the
                   corresponding network instance";
            }
            uses test-point-location-info;
            ordered-by user;
            description
             "list of test point locations.";
            }
            description
              "Serves as top-level container for test point location list.";
          }
        }
        case group-lsp-id-location-type {
          when "'tp-address-type-value' = 'lsp-id-address-type'" {
            description "when test point address is equal to lspid.";
          }
          container test-point-lsp-id-location-list {
            list test-point-locations {
            key "lsp-id-location";
            leaf lsp-id-location {
              type string;
              description
                "LSP Id.";
            }
            leaf vrf {
              type routing-instance-ref;
                  description
                  "The vrf is used to describe the



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                   corresponding network instance";
            }
            uses test-point-location-info;
            ordered-by user;
            description
             "list of test point locations.";
            }
            description
              "Serves as top-level container for test point location list.";
          }
        }
        case group-system-id-location-type {
          when "'tp-address-type-value' = 'system-id-address-type'" {
            description "when test point address is equal to
                         system info.";
          }
          container test-point-system-info-location-list {
            list test-point-locations {
            key "system-id-location";
            leaf system-id-location {
              type inet:uri;
              description
                "System Id.";
            }
            leaf vrf {
              type routing-instance-ref;
                  description
                  "The vrf is used to describe the
                   corresponding network instance";
            }
            uses test-point-location-info;
            ordered-by user;
            description
              "list of test point locations.";
            }
            description
              "Serves as top-level container for test point location list.";
          }
        }
        description
          "Choice of address types.";
      }
    }

    augment "/nd:networks/nd:network/nd:node"{
      description
        "Augment test points of connectionless oam.";
      uses test-point-locations;



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    }

    grouping path-discovery-data {
      description "Path discovery related data output from nodes.";
      container src-test-point {
        description "Source test point.";
        uses tp-address-vrf;
      }
      container dest-test-point {
        description "Destination test point.";
        uses tp-address-vrf;
      }
      leaf sequence-number {
        type uint64;
        description "Sequence number in data packets.";
      }
      leaf hop-cnt {
        type uint8;
        description "hop count.";
      }

      uses session-packet-statistics;
      uses session-error-statistics;
      uses session-delay-statistics;
      uses session-jitter-statistics;

      container path-verification {
        description "Optional path verification related information.";
        leaf flow-info {
          type string;
          description
            "ACL name that refers to the flow, if any.";
        }
        uses session-path-verification-statistics;
      }

      container path-trace-info {
        description "Optional path trace per-hop test point information.
                     The list has typically a single element for per-hop
                     cases like path-discovery RPC but allows a list of
                     hop related information for other types of
                     data retrieval methods.";
        list path-trace-info-list {
          key "index";
          description
            "Path trace information list.";
          leaf index {
            type uint32;



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            description "Trace information index.";
          }

          uses tp-address-vrf;

          leaf timestamp-val {
            type yang:date-and-time;
            description "Timestamp value";
          }
          leaf ingress-intf-name {
            type if:interface-ref;
            description
              "Ingress interface name";
          }
          leaf egress-intf-name {
            type if:interface-ref;
            description
              "Egress interface name";
          }
          leaf app-meta-data {
            type uint32;
            description
              "Application specific data added by node.";
          }
        }
      }
    }

    grouping continuity-check-data {
      description "Continuity check data output from nodes.";
      container src-test-point {
        description "Source test point.";
        uses tp-address-vrf;

        leaf egress-intf-name {
          type if:interface-ref;
          description
            "Egress interface name";
        }
      }
      container dest-test-point {
        description "Destination test point.";
        uses tp-address-vrf;

        leaf ingress-intf-name {
          type if:interface-ref;
          description
            "Ingress interface name";



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        }
      }
      leaf sequence-number {
        type uint64;
        description "Sequence number.";
      }
      leaf hop-cnt {
        type uint8;
        description "hop count.";
      }

      uses session-packet-statistics;
      uses session-error-statistics;
      uses session-delay-statistics;
      uses session-jitter-statistics;
    }

    container oper {
      if-feature continuity-check;
      config "false";
      description "cc operational information.";
      container cc-ipv4-sessions-statistics {
        description "cc ipv4 sessions";
        uses cc-session-statsitics;
      }
      container cc-ipv6-sessions-statistics {
        description "cc ipv6 sessions";
        uses cc-session-statsitics;
      }
    }
}




                            YANG module of OAM

   <CODE ENDS>

5.  CL model applicability

   ietf-connectionless-oam model defined in this document provides
   technology-independent abstraction of key OAM constructs for
   connectionless protocols.  This model can be further extended to
   include technology specific details, e.g., adding new data nodes with
   technology specific functions and parameters into proper anchor
   points of the base model, so as to develop a technology-specific
   connectionless OAM model.



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   This section demonstrates the usability of the connectionless YANG
   OAM data model to various connectionless OAM technologies, e.g., BFD,
   LSP ping.  Note that, in this section, we only present several
   snippets of technology-specific model extensions for illustrative
   purposes.  The complete model extensions should be worked on in
   respective protocol working groups.

5.1.  BFD Extension

   The following sections shows how the "ietf-connectionless-oam" model
   can be extended to cover BFD technology.  For this purpose, a set of
   extension are introduced such as technology-type extension and test-
   point attributes extension.

   Note that in BFD WG, there is a BFD yang data model
   [I-D.ietf-bfd-yang] to be produced.  Users can choose to use both BFD
   model and "ietf-connectioless-oam" as basis and augment the "ietf-
   connectionless-oam" model with bfd specific details.  The bfd
   specific details can be the grouping defined in the BFD model.

5.1.1.  technology type extension

   No BFD technology type has been defined in the "ietf-connectionless-
   oam" model.  Therefore a technology type extension is required in the
   LIME BFD model.

   The snippet below depicts an example of augmenting "bfd" type into
   the ietf-connectionless-oam":

           augment "/nd:networks/nd:network/nd:node/"
           +"coam:location-type/coam:ipv4-location-type"
           +"/coam:test-point-ipv4-location-list/"
           +"coam:test-point-locations/coam:technology"
           +"/coam:technology-string"
           {
             leaf bfd{
              type string;
             }
           }



5.1.2.  test point attributes extension

   To derive a model for bfd technology, the "ietf-connectionless-oam"
   model can be extended.  Some data nodes for bfd specific parameters
   can be defined and inserted into the proper "test-point-location"




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   list.  Or some new "location-type" cases can be added to support the
   some bfd technologies such as "bfd over MPLS-TE", etc.

5.1.2.1.  Define and insert new nodes into corresponding test-point-
          location

   In the "ietf-connectionless-oam" model, multiple "test-point-
   location" lists are defined under the "location-type" choice node.
   Therefore, to derive model for some bfd technologies( such as ip
   single-hop, ip multi-hops, etc), data nodes for bfd specific details
   can be defined and inserted into corresponding "test-point-locations"
   list.  In this section, we reuse some groupings which are defined in
   [I-D.ietf-bfd-yang] to derive following example.

   The snippet below shows how the "ietf-connectionless-oam" model can
   be extended to "BFD IP single-hop":

           augment "/nd:networks/nd:network/nd:node/"
           +"coam:location-type/coam:ipv4-location-type"
           +"/coam:test-point-ipv4-location-list/"
           +"coam:test-point-locations"
           {
           container session-cfg {
             description "BFD IP single-hop session configuration";
             list sessions {
               key "interface dest-addr";
               description "List of IP single-hop sessions";
               leaf interface {
                 type if:interface-ref;
                 description
                   "Interface on which the BFD session is running.";
               }
               leaf dest-addr {
                 type inet:ip-address;
                 description "IP address of the peer";
               }

               uses bfd:bfd-grouping-common-cfg-parms;
               uses bfd:bfd-grouping-echo-cfg-parms;
             }
           }
           }

   Edit note: To prevent new attribute to be defined in the CL extension
   model,[I-D.ietf-bfd-yang] should define the attributes that are used
   by CL model as grouping, then CL extension model can reuse these
   grouping.  We will make accordingly change when these grouping are
   available in the BFD model.



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   Similar augmentations can be defined to support other BFD
   technologies such as BFD IP multi-hop, BFD over MPLS, etc.

5.1.2.2.  Add new location-type cases

   In the "ietf-connectionless-oam" model, If no a proper "test-point-
   locations" can be extended, new "location-type" cases can be defined
   and inserted into the "location-type" choice node.

   Therefore, the model user can flexible add "location-type" to support
   other kinds of test point which are not defined in the "ietf-
   connectionless-oam" model.  In this section, we add a new "location-
   type" case and reuse some groupings which are defined in
   [I-D.ietf-bfd-yang] to derive the following example.

   The snippet below shows how the "ietf-connectionless-oam" model can
   be extended to "BFD over MPLS-TE":

           augment "/nd:networks/nd:network/nd:node/coam:location-type"{
            case te-location{
             list test-point-location-list{
              key "tunnel-name";
              leaf tunnel-name{
               type leafref{
                    path "/te:te/te:tunnels/te:tunnel/te:name";
                   }
                   description
                   "point to a te instance.";
              }
               uses bfd:bfd-grouping-common-cfg-parms;
           uses bfd-mpls:bfd-encap-cfg;
             }
            }
           }


   Similar augmentations can be defined to support other BFD
   technologies such as BFD over LAG, etc.

5.2.  LSP ping extension

   The following sections shows how the "ietf-connectionless-oam" model
   can be extended to cover LSP ping technology.  For this purpose, a
   set of extension are introduced such as technology-type extension and
   test-point attributes extension.

   Note that in MPLS WG, there is a LSP Ping yang data model
   [I-D.draft-zheng-mpls-lsp-ping-yang-cfg] to be produced.  Users can



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   choose to use both LSP Ping model and "ietf-connectioless-oam" as
   basis and augment the "ietf-connectionless-oam" model with LSP Ping
   specific details.  The LSP Ping specific details can be the grouping
   defined in the LSP ping model.

5.2.1.  technology type extension

   No lsp-ping technology type has been defined in the "ietf-
   connectionless-oam" model.  Therefore a technology type extension is
   required in the LIME LSP ping model.

   The snippet below depicts an example of augmenting "lsp-ping" type
   into the "ietf-connectionless-oam":

           augment "/nd:networks/nd:network/nd:node/"
           +"coam:location-type/coam:ipv4-location-type"
           +"/coam:test-point-ipv4-location-list/"
           +"coam:test-point-locations/coam:technology"
           +"/coam:technology-string"
           {
            leaf lsp-ping{
              type string;
             }
           }


5.2.2.  test point attributes extension

   In order to derive a model for lsp-ping, the "ietf-connectionless-
   oam" model can be extended.  Some data nodes for lsp-ping specific
   parameters can be defined and inserted into the proper "test-point-
   location" list.

   User can reuse the attributes or groupings which are defined in
   [I-D.draft-zheng-mpls-lsp-ping-yang-cfg] to derive the "lime lsp
   ping" model.

   The snippet below depicts an example of augmenting lsp ping
   attributes into the "test-point-locations" list:












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           augment "/nd:networks/nd:network/nd:node/"
           +"coam:location-type/coam:ipv4-location-type"
           +"/coam:test-point-ipv4-location-list/"
           +"coam:test-point-locations"
           {
   list lsp-ping {
            key "lsp-ping-name";
            leaf lsp-ping-name {
             type string {
               length "1..31";
            }
           mandatory "true";
           description "LSP Ping test name.";
           ......
         }


   Edit note: To prevent new attribute to be defined in the CL extension
   model,[I-D.draft-zheng-mpls-lsp-ping-yang-cfg] should define the
   attributes that are used by CL model as grouping, then CL extension
   model can reuse these grouping.  We will make accordingly change when
   these grouping are available in the LSP ping model.

6.  Security Considerations

   TBD.

7.  IANA Considerations

   This document registers a URI in the IETF XML registry [RFC3688]
   [RFC3688].  Following the format in RFC 3688, the following
   registration is requested to be made:

   URI: urn:ietf:params:xml:ns:yang:ietf-connectionless-oam

   Registrant Contact: The IESG.

   XML: N/A, the requested URI is an XML namespace.

   This document registers a YANG module in the YANG Module Names
   registry [RFC6020].

name: ietf-connectionless-oam namespace: urn:ietf:params:xml:ns:yang:ietf-connectionless-oam
   prefix: goam reference: RFC XXXX







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8.  Normative References

   [I-D.draft-ietf-i2rs-yang-network-topo]
              Clemm, A., Medved, J., Tkacik, T., Varga, R., Bahadur, N.,
              Ananthakrishnan, H., and X. Liu, "A YANG Data Model for
              Network Topologies", I-D draft-ietf-i2rs-yang-network-
              topo-05, July 2016.

   [I-D.draft-zheng-mpls-lsp-ping-yang-cfg]
              Zheng, L., Aldrin, S., Zheng, G., Mirsky, G., and R.
              Rahman, "Yang Data Model for LSP-PING", I-D draft-zheng-
              mpls-lsp-ping-yang-cfg-03, March 2016.

   [I-D.ietf-bfd-yang]
              Zheng, L., Rahman, R., Networks, J., Jethanandani, M., and
              G. Mirsky, "Yang Data Model for Bidirectional Forwarding
              Detection (BFD)", draft-ietf-bfd-yang-03 (work in
              progress), July 2016.

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

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

   [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,
              <http://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,
              <http://www.rfc-editor.org/info/rfc6242>.

   [RFC792]   Postel, J., "Internet Control Message Protocol", RFC 792,
              September 1981.

Authors' Addresses









Kumar, et al.              Expires May 4, 2017                 [Page 49]


Internet-Draft       Connection-Less OAM YANG model         October 2016


   Deepak Kumar
   CISCO Systems
   510 McCarthy Blvd
   Milpitas, CA  95035
   USA

   Email: dekumar@cisco.com


   Michael Wang
   Huawei Technologies,Co.,Ltd
   101 Software Avenue, Yuhua District
   Nanjing  210012
   China

   Email: wangzitao@huawei.com


   Qin Wu
   Huawei
   101 Software Avenue, Yuhua District
   Nanjing, Jiangsu  210012
   China

   Email: bill.wu@huawei.com


   Reshad Rahman
   CISCO Systems
   2000 Innovation Drive
   KANATA, ONTARIO  K2K 3E8
   CANADA

   Email: rrahman@cisco.com


   Srihari Raghavan
   CISCO Systems
   TRIL INFOPARK SEZ, Ramanujan IT City
   NEVILLE BLOCK, 2nd floor, Old Mahabalipuram Road
   CHENNAI, TAMIL NADU  600113
   INDIA

   Email: srihari@cisco.com







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