Internet DRAFT - draft-liu-teas-yang-te-topo

draft-liu-teas-yang-te-topo







TEAS Working Group                                                X. Liu
Internet-Draft                                                  Ericsson
Intended status: Standards Track                              I. Bryskin
Expires: September 26, 2015                      ADVA Optical Networking
                                                               V. Beeram
                                                        Juniper Networks
                                                                 T. Saad
                                                      Cisco Systems Inc.
                                                                 H. Shah
                                                                   Ciena
                                                          March 25, 2015


                   YANG Data Model for TE Topologies
                     draft-liu-teas-yang-te-topo-01

Abstract

   This document defines a YANG data model for representing and
   manipulating TE Topologies.

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 September 26, 2015.

Copyright Notice

   Copyright (c) 2015 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



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   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
     1.1.  Tree Structure - Legend . . . . . . . . . . . . . . . . .   2
     1.2.  Prefixes in Data Node Names . . . . . . . . . . . . . . .   3
     1.3.  Terminology . . . . . . . . . . . . . . . . . . . . . . .   4
   2.  Design Considerations . . . . . . . . . . . . . . . . . . . .   4
     2.1.  Generic extensible Model  . . . . . . . . . . . . . . . .   4
       2.1.1.  Generic TE Link Attributes  . . . . . . . . . . . . .   4
       2.1.2.  Generic TE Node Attributes  . . . . . . . . . . . . .   4
       2.1.3.  TED Information Sources . . . . . . . . . . . . . . .   4
     2.2.  Overlay/Underlay Relationship . . . . . . . . . . . . . .   5
     2.3.  Scheduling Parameters . . . . . . . . . . . . . . . . . .   5
     2.4.  Abstract TE Topologies  . . . . . . . . . . . . . . . . .   5
     2.5.  Open Items  . . . . . . . . . . . . . . . . . . . . . . .   6
   3.  Tree Structure  . . . . . . . . . . . . . . . . . . . . . . .   6
     3.1.  TE Topology Yang Module . . . . . . . . . . . . . . . . .  29
   4.  Normative References  . . . . . . . . . . . . . . . . . . . .  49
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  49

1.  Introduction

   YANG [RFC6020] a data definition language that was introduced to
   define the contents of a conceptual data store that allows networked
   devices to be managed using NETCONF [RFC6241].  YANG is proving
   relevant beyond its initial confines, as bindings to other interfaces
   (e.g.  ReST) and encoding other than XML (e.g.  JSON) are being
   defined.  Furthermore, YANG data models can be used as the basis of
   implementation for other interface, such as CLI and programmatic
   APIs.  This document defines a YANG data model for representing and
   manipulating TE Topologies.  This model contains technology agnostic
   TE Topology building blocks that can be augmented and used by other
   technology-specific TE Topology models.

1.1.  Tree Structure - Legend

   A simplified graphical representation of the data model is presented
   in Section 3 of this document.  The following notations are used for
   the YANG model data tree representation.







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

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

     <flags> is one of:
       rw  for read-write configuration data
       ro  for read-only non-configuration data
       -x  for execution 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 node
       ! for a presence container
       * for a leaf-list or list
       Brackets [<keys>] for a list's keys
       Curly braces {<condition>} for optional feature that make node
       conditional
       Colon : for marking case nodes
       Ellipses ("...") subtree contents not shown

       Parentheses enclose choice and case nodes, and case nodes are
        also marked with a colon (":").

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

1.2.  Prefixes in Data Node Names

   In this document, names of data nodes and other data model objects
   are prefixed using the standard prefix associated with the
   corresponding YANG imported modules, as shown in Table 1.

            +--------+-----------------+-----------+
            | Prefix | YANG module     | Reference |
            +--------+-----------------+-----------+
            | yang   | ietf-yang-types | [RFC6991] |
            | inet   | ietf-inet-types | [RFC6991] |
            +--------+-----------------+-----------+

          Table 1: Prefixes and corresponding YANG modules




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1.3.  Terminology

   In this document, the key words "MUST", "MUST NOT", "REQUIRED",
   "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY",
   and "OPTIONAL" are to be interpreted as described in BCP 14, RFC 2119
   [RFC2119].

2.  Design Considerations

2.1.  Generic extensible Model

   The TE Topology model proposed in this document is meant to be
   technology agnostic.  Other technology specific TE Topology models
   can augment and use the building blocks provided by the proposed
   model.

2.1.1.  Generic TE Link Attributes

   The model covers the definitions for generic TE Link attributes -
   bandwidth, admin groups, SRLGs, switching capabilities, TE metric
   extensions etc.

2.1.2.  Generic TE Node Attributes

   The model covers the definitions for generic TE Node attributes like
   connectivity matrix.

      +--rw connectivity-matrix* [id]
         +--rw id            uint32
         +--rw from-link
            +--rw topo-ref?       leafref
            +--rw node-ref?       leafref
            +--rw link-end-ref?   leafref
         +--rw to-link
            +--rw topo-ref?       leafref
            +--rw node-ref?       leafref
            +--rw link-end-ref?   leafref
         +--rw is-allowed?        Boolean

2.1.3.  TED Information Sources

   The model allows each TE topological element to have multiple TE
   information sources (OSPF-TE, ISIS-TE, BGP-LS, User-Configured,
   Other).  Each information source is associated with a credibility
   preference to indicate precedence.

   The model captures overlay and underlay relationship for TE nodes/
   links.  For example - in networks where multiple TE Topologies are



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   built hierarchically, this model allows the user to start from a
   specific topological element in the top most topology and traverse
   all the way down to the supporting topological elements in the bottom
   most topology.

2.2.  Overlay/Underlay Relationship

      +--rw node* [te-node-id]
                   :
         +--rw te-node-attributes
                   :
            +--rw underlay-topology?  leafref {te-topology-hierarchy}?


      +--rw link* [source-te-node-id source-te-link-id dest-te-node-id
                   dest-te-link-id]
                   :
         +--rw te-link-attributes
            +--rw underlay! {te-topology-hierarchy}?
               +--rw underlay-path
                       :
               +--rw underlay-backup-path
                       :
               +--rw underlay-protection-type?   uint16
               +--rw underlay-trail-src
                   :
               +--rw underlay-trail-des
                   :

2.3.  Scheduling Parameters

   The model allows time scheduling parameters to be specified for each
   topological element.  These parameters allow the provider to present
   different topological views to the client at different time slots.

      +--rw schedules* [schedule-id]
      |  +--rw schedule-id          uint32
      |  +--rw start?               yang:date-and-time
      |  +--rw schedule-duration?   string
      |  +--rw repeat-interval?     string

2.4.  Abstract TE Topologies

   The model allows the provider to present the network in abstract
   terms on per client basis and facilitates the notion of "TE Topology
   as a service".  These topologies are typically decoupled from the
   actual network topology and are supposed to be fully comprehensible
   by the clients and contain sufficient information for the client path



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   computers to select service paths according to the client policies.
   The model also allows the client to request changes to the abstract
   TE Topology that is presented to it and thus manipulate it.

2.5.  Open Items

   o  Relationship with "generic network topology" model: The generic
      network topology building blocks are discussed in [YANG-NET-TOPO].
      This version of the document does not use any of those building
      blocks.  The authors would like to explore the possibility of
      doing that in future revisions of this document.

   o  Incremental notifications: The model proposed in this version does
      not cover incremental notifications.  The authors intend to add
      this in future revisions of the document.

3.  Tree Structure

module: ietf-te-topology
   +--rw te-topologies
   |  +--rw topology* [te-topology-id]
   |  |  +--rw te-topology-id    te-topology-id
   |  |  +--rw topology-types
   |  |  |  +--rw te-topology!
   |  |  +--rw node* [te-node-id]
   |  |  |  +--rw te-node-id            te-node-id
   |  |  |  +--rw te-node-template?     leafref
   |  |  |  +--rw te-node-attributes
   |  |  |     +--rw schedules* [schedule-id]
   |  |  |     |  +--rw schedule-id          uint32
   |  |  |     |  +--rw start?               yang:date-and-time
   |  |  |     |  +--rw schedule-duration?   string
   |  |  |     |  +--rw repeat-interval?     string
   |  |  |     +--rw name?                  inet:domain-name
   |  |  |     +--rw signaling-address*     inet:ip-address
   |  |  |     +--rw flag*                  flag-type
   |  |  |     +--rw is-abstract?           boolean
   |  |  |     +--rw underlay-topology?     leafref
 {te-topology-hierarchy}?
   |  |  |     +--rw te-link* [te-link-id]
   |  |  |     |  +--rw te-link-id         te-link-id
   |  |  |     |  +--rw (stack-level)?
   |  |  |     |     +--:(bundle)
   |  |  |     |     |  +--rw bundled-links
   |  |  |     |     |     +--rw bundled-link* [sequence]
   |  |  |     |     |        +--rw sequence       uint32
   |  |  |     |     |        +--rw te-link-ref?   leafref
   |  |  |     |     +--:(component)



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   |  |  |     |        +--rw component-links
   |  |  |     |           +--rw component-link* [sequence]
   |  |  |     |              +--rw sequence              uint32
   |  |  |     |              +--rw component-link-ref?   leafref
   |  |  |     +--rw connectivity-matrix* [id]
   |  |  |     |  +--rw id            uint32
   |  |  |     |  +--rw from-link
   |  |  |     |  |  +--rw topo-ref?       leafref
   |  |  |     |  |  +--rw node-ref?       leafref
   |  |  |     |  |  +--rw link-end-ref?   leafref
   |  |  |     |  +--rw to-link
   |  |  |     |  |  +--rw topo-ref?       leafref
   |  |  |     |  |  +--rw node-ref?       leafref
   |  |  |     |  |  +--rw link-end-ref?   leafref
   |  |  |     |  +--rw is-allowed?   boolean
   |  |  |     +--rw ted
   |  |  |        +--rw te-router-id-ipv4?    inet:ipv4-address
   |  |  |        +--rw te-router-id-ipv6?    inet:ipv6-address
   |  |  |        +--rw ipv4-local-address* [ipv4-prefix]
   |  |  |        |  +--rw ipv4-prefix    inet:ipv4-prefix
   |  |  |        +--rw ipv6-local-address* [ipv6-prefix]
   |  |  |        |  +--rw ipv6-prefix      inet:ipv6-prefix
   |  |  |        |  +--rw prefix-option?   uint8
   |  |  |        +--rw pcc-capabilities?     pcc-capabilities
   |  |  +--rw link* [source-te-node-id source-te-link-id
                      dest-te-node-id dest-te-link-id]
   |  |     +--rw source-te-node-id     leafref
   |  |     +--rw source-te-link-id     leafref
   |  |     +--rw dest-te-node-id       leafref
   |  |     +--rw dest-te-link-id       leafref
   |  |     +--rw te-link-template?     leafref
   |  |     +--rw te-link-attributes
   |  |        +--rw schedules* [schedule-id]
   |  |        |  +--rw schedule-id          uint32
   |  |        |  +--rw start?               yang:date-and-time
   |  |        |  +--rw schedule-duration?   string
   |  |        |  +--rw repeat-interval?     string
   |  |        +--rw name?          string
   |  |        +--rw flag*          flag-type
   |  |        +--rw is-abstract?   boolean
   |  |        +--rw underlay! {te-topology-hierarchy}?
   |  |        |  +--rw underlay-path
   |  |        |  |  +--rw topology-id?    leafref
   |  |        |  |  +--rw path-element* [path-element-id]
   |  |        |  |     +--rw path-element-id    uint32
   |  |        |  |     +--rw loose?             boolean
   |  |        |  |     +--rw (element-type)?
   |  |        |  |        +--:(numbered-link)



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   |  |        |  |        |  +--rw link-ip-address?  inet:ip-address
   |  |        |  |        +--:(unnumbered-link)
   |  |        |  |        |  +--rw link-node-id?      uint32
   |  |        |  |        |  +--rw te-link-id?        uint32
   |  |        |  |        +--:(node)
   |  |        |  |        |  +--rw te-node-id?        uint32
   |  |        |  |        +--:(label)
   |  |        |  |           +--rw label?             uint32
   |  |        |  +--rw underlay-backup-path
   |  |        |  |  +--rw topology-id?    leafref
   |  |        |  |  +--rw path-element* [path-element-id]
   |  |        |  |     +--rw path-element-id    uint32
   |  |        |  |     +--rw loose?             boolean
   |  |        |  |     +--rw (element-type)?
   |  |        |  |        +--:(numbered-link)
   |  |        |  |        |  +--rw link-ip-address?  inet:ip-address
   |  |        |  |        +--:(unnumbered-link)
   |  |        |  |        |  +--rw link-node-id?      uint32
   |  |        |  |        |  +--rw te-link-id?        uint32
   |  |        |  |        +--:(node)
   |  |        |  |        |  +--rw te-node-id?        uint32
   |  |        |  |        +--:(label)
   |  |        |  |           +--rw label?             uint32
   |  |        |  +--rw underlay-protection-type?   uint16
   |  |        |  +--rw underlay-trail-src
   |  |        |  |  +--rw topo-ref?       leafref
   |  |        |  |  +--rw node-ref?       leafref
   |  |        |  |  +--rw link-end-ref?   leafref
   |  |        |  +--rw underlay-trail-des
   |  |        |     +--rw topo-ref?       leafref
   |  |        |     +--rw node-ref?       leafref
   |  |        |     +--rw link-end-ref?   leafref
   |  |        +--rw ted
   |  |           +--rw admin-status?                    enumeration
   |  |           +--rw oper-status?                     enumeration
   |  |           +--rw area-id?                         binary
   |  |           +--rw performance-metric-throttle
{te-performance-metric}?
   |  |           |  +--rw unidirectional-delay-offset?        uint32
   |  |           |  +--rw measure-interval?                   uint32
   |  |           |  +--rw advertisement-interval?             uint32
   |  |           |  +--rw suppression-interval?               uint32
   |  |           |  +--rw threshold-out
   |  |           |  |  +--rw unidirectional-delay?            uint32
   |  |           |  |  +--rw unidirectional-min-delay?        uint32
   |  |           |  |  +--rw unidirectional-max-delay?        uint32
   |  |           |  |  +--rw unidirectional-delay-variation?  uint32
   |  |           |  |  +--rw unidirectional-packet-loss?   decimal64



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   |  |           |  |  +--rw unidirectional-residual-bandwidth?
decimal64
   |  |           |  |  +--rw unidirectional-available-bandwidth?
decimal64
   |  |           |  |  +--rw unidirectional-utilized-bandwidth?
decimal64
   |  |           |  +--rw threshold-in
   |  |           |  |  +--rw unidirectional-delay?
uint32
   |  |           |  |  +--rw unidirectional-min-delay?
uint32
   |  |           |  |  +--rw unidirectional-max-delay?
uint32
   |  |           |  |  +--rw unidirectional-delay-variation?
uint32
   |  |           |  |  +--rw unidirectional-packet-loss?
decimal64
   |  |           |  |  +--rw unidirectional-residual-bandwidth?
decimal64
   |  |           |  |  +--rw unidirectional-available-bandwidth?
decimal64
   |  |           |  |  +--rw unidirectional-utilized-bandwidth?
decimal64
   |  |           |  +--rw threshold-accelerated-advertisement
   |  |           |     +--rw unidirectional-delay?            uint32
   |  |           |     +--rw unidirectional-min-delay?        uint32
   |  |           |     +--rw unidirectional-max-delay?        uint32
   |  |           |     +--rw unidirectional-delay-variation?  uint32
   |  |           |     +--rw unidirectional-packet-loss?   decimal64
   |  |           |     +--rw unidirectional-residual-bandwidth?
decimal64
   |  |           |     +--rw unidirectional-available-bandwidth?
decimal64
   |  |           |     +--rw unidirectional-utilized-bandwidth?
decimal64
   |  |           +--rw information-source?               enumeration
   |  |           +--rw credibility-preference?                uint16
   |  |           +--rw link-index?                            uint64
   |  |           +--rw administrative-group* [sequence]
   |  |           |  +--rw sequence      uint32
   |  |           |  +--rw ag-element?   uint32
   |  |           +--rw max-link-bandwidth?                 decimal64
   |  |           +--rw max-resv-link-bandwidth?            decimal64
   |  |           +--rw unreserved-bandwidth* [priority]
   |  |           |  +--rw priority     uint8
   |  |           |  +--rw bandwidth?   decimal64
   |  |           +--rw te-default-metric?                  uint32
   |  |           +--rw performance-metric {te-performance-metric}?



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   |  |           |  +--rw measurement
   |  |           |  |  +--rw unidirectional-delay?            uint32
   |  |           |  |  +--rw unidirectional-min-delay?        uint32
   |  |           |  |  +--rw unidirectional-max-delay?        uint32
   |  |           |  |  +--rw unidirectional-delay-variation?  uint32
   |  |           |  |  +--rw unidirectional-packet-loss?   decimal64
   |  |           |  |  +--rw unidirectional-residual-bandwidth?
decimal64
   |  |           |  |  +--rw unidirectional-available-bandwidth?
decimal64
   |  |           |  |  +--rw unidirectional-utilized-bandwidth?
decimal64
   |  |           |  +--rw normality
   |  |           |     +--rw unidirectional-delay?
performance-metric-normality
   |  |           |     +--rw unidirectional-min-delay?
performance-metric-normality
   |  |           |     +--rw unidirectional-max-delay?
performance-metric-normality
   |  |           |     +--rw unidirectional-delay-variation?
performance-metric-normality
   |  |           |     +--rw unidirectional-packet-loss?
performance-metric-normality
   |  |           |     +--rw unidirectional-residual-bandwidth?
performance-metric-normality
   |  |           |     +--rw unidirectional-available-bandwidth?
performance-metric-normality
   |  |           |     +--rw unidirectional-utilized-bandwidth?
performance-metric-normality
   |  |           +--rw link-protection-type?
enumeration
   |  |           +--rw interface-switching-capabilities*
[switching-capability]
   |  |           |  +--rw switching-capability
ted:switching-capabilities
   |  |           |  +--rw encoding?
ted:encoding-type
   |  |           |  +--rw max-lsp-bandwidth* [priority]
   |  |           |  |  +--rw priority     uint8
   |  |           |  |  +--rw bandwidth?   decimal64
   |  |           |  +--rw packet-switch-capable
   |  |           |  |  +--rw minimum-lsp-bandwidth?   decimal64
   |  |           |  |  +--rw interface-mtu?           uint16
   |  |           |  +--rw time-division-multiplex-capable
   |  |           |     +--rw minimum-lsp-bandwidth?   decimal64
   |  |           |     +--rw indication?              enumeration
   |  |           +--rw srlg
   |  |           |  +--rw srlg-values* [srlg-value]



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   |  |           |     +--rw srlg-value    uint32
   |  |           +--rw alt-information-sources* [information-source]
   |  |              +--rw information-source             enumeration
   |  |              +--rw credibility-preference?             uint16
   |  |              +--rw link-index?                         uint64
   |  |              +--rw administrative-group* [sequence]
   |  |              |  +--rw sequence      uint32
   |  |              |  +--rw ag-element?   uint32
   |  |              +--rw max-link-bandwidth?              decimal64
   |  |              +--rw max-resv-link-bandwidth?         decimal64
   |  |              +--rw unreserved-bandwidth* [priority]
   |  |              |  +--rw priority     uint8
   |  |              |  +--rw bandwidth?   decimal64
   |  |              +--rw te-default-metric?                  uint32
   |  |              +--rw performance-metric
 {te-performance-metric}?
   |  |              |  +--rw measurement
   |  |              |  |  +--rw unidirectional-delay?         uint32
   |  |              |  |  +--rw unidirectional-min-delay?     uint32
   |  |              |  |  +--rw unidirectional-max-delay?     uint32
   |  |              |  |  +--rw unidirectional-delay-variation?
uint32
   |  |              |  |  +--rw unidirectional-packet-loss?
decimal64
   |  |              |  |  +--rw unidirectional-residual-bandwidth?
decimal64
   |  |              |  |  +--rw unidirectional-available-bandwidth?
decimal64
   |  |              |  |  +--rw unidirectional-utilized-bandwidth?
decimal64
   |  |              |  +--rw normality
   |  |              |     +--rw unidirectional-delay?
performance-metric-normality
   |  |              |     +--rw unidirectional-min-delay?
performance-metric-normality
   |  |              |     +--rw unidirectional-max-delay?
performance-metric-normality
   |  |              |     +--rw unidirectional-delay-variation?
performance-metric-normality
   |  |              |     +--rw unidirectional-packet-loss?
performance-metric-normality
   |  |              |     +--rw unidirectional-residual-bandwidth?
performance-metric-normality
   |  |              |     +--rw unidirectional-available-bandwidth?
performance-metric-normality
   |  |              |     +--rw unidirectional-utilized-bandwidth?
performance-metric-normality
   |  |              +--rw link-protection-type?



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enumeration
   |  |              +--rw interface-switching-capabilities*
[switching-capability]
   |  |              |  +--rw switching-capability
ted:switching-capabilities
   |  |              |  +--rw encoding?
ted:encoding-type
   |  |              |  +--rw max-lsp-bandwidth* [priority]
   |  |              |  |  +--rw priority     uint8
   |  |              |  |  +--rw bandwidth?   decimal64
   |  |              |  +--rw packet-switch-capable
   |  |              |  |  +--rw minimum-lsp-bandwidth?   decimal64
   |  |              |  |  +--rw interface-mtu?           uint16
   |  |              |  +--rw time-division-multiplex-capable
   |  |              |     +--rw minimum-lsp-bandwidth?   decimal64
   |  |              |     +--rw indication?              enumeration
   |  |              +--rw srlg
   |  |                 +--rw srlg-values* [srlg-value]
   |  |                    +--rw srlg-value    uint32
   |  +--rw node-template* [name]
   |  |  +--rw name                  te-template-name
   |  |  +--rw te-node-attributes
   |  |     +--rw schedules* [schedule-id]
   |  |     |  +--rw schedule-id          uint32
   |  |     |  +--rw start?               yang:date-and-time
   |  |     |  +--rw schedule-duration?   string
   |  |     |  +--rw repeat-interval?     string
   |  |     +--rw name?                  inet:domain-name
   |  |     +--rw signaling-address*     inet:ip-address
   |  |     +--rw flag*                  flag-type
   |  |     +--rw is-abstract?           boolean
   |  |     +--rw underlay-topology?     leafref
{te-topology-hierarchy}?
   |  |     +--rw te-link* [te-link-id]
   |  |     |  +--rw te-link-id         te-link-id
   |  |     |  +--rw (stack-level)?
   |  |     |     +--:(bundle)
   |  |     |     |  +--rw bundled-links
   |  |     |     |     +--rw bundled-link* [sequence]
   |  |     |     |        +--rw sequence       uint32
   |  |     |     |        +--rw te-link-ref?   leafref
   |  |     |     +--:(component)
   |  |     |        +--rw component-links
   |  |     |           +--rw component-link* [sequence]
   |  |     |              +--rw sequence              uint32
   |  |     |              +--rw component-link-ref?   leafref
   |  |     +--rw connectivity-matrix* [id]
   |  |     |  +--rw id            uint32



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   |  |     |  +--rw from-link
   |  |     |  |  +--rw topo-ref?       leafref
   |  |     |  |  +--rw node-ref?       leafref
   |  |     |  |  +--rw link-end-ref?   leafref
   |  |     |  +--rw to-link
   |  |     |  |  +--rw topo-ref?       leafref
   |  |     |  |  +--rw node-ref?       leafref
   |  |     |  |  +--rw link-end-ref?   leafref
   |  |     |  +--rw is-allowed?   boolean
   |  |     +--rw ted
   |  |        +--rw te-router-id-ipv4?    inet:ipv4-address
   |  |        +--rw te-router-id-ipv6?    inet:ipv6-address
   |  |        +--rw ipv4-local-address* [ipv4-prefix]
   |  |        |  +--rw ipv4-prefix    inet:ipv4-prefix
   |  |        +--rw ipv6-local-address* [ipv6-prefix]
   |  |        |  +--rw ipv6-prefix      inet:ipv6-prefix
   |  |        |  +--rw prefix-option?   uint8
   |  |        +--rw pcc-capabilities?     pcc-capabilities
   |  +--rw link-template* [name]
   |     +--rw name                  te-template-name
   |     +--rw te-link-attributes
   |        +--rw schedules* [schedule-id]
   |        |  +--rw schedule-id          uint32
   |        |  +--rw start?               yang:date-and-time
   |        |  +--rw schedule-duration?   string
   |        |  +--rw repeat-interval?     string
   |        +--rw name?          string
   |        +--rw flag*          flag-type
   |        +--rw is-abstract?   boolean
   |        +--rw underlay! {te-topology-hierarchy}?
   |        |  +--rw underlay-path
   |        |  |  +--rw topology-id?    leafref
   |        |  |  +--rw path-element* [path-element-id]
   |        |  |     +--rw path-element-id    uint32
   |        |  |     +--rw loose?             boolean
   |        |  |     +--rw (element-type)?
   |        |  |        +--:(numbered-link)
   |        |  |        |  +--rw link-ip-address?   inet:ip-address
   |        |  |        +--:(unnumbered-link)
   |        |  |        |  +--rw link-node-id?      uint32
   |        |  |        |  +--rw te-link-id?        uint32
   |        |  |        +--:(node)
   |        |  |        |  +--rw te-node-id?        uint32
   |        |  |        +--:(label)
   |        |  |           +--rw label?             uint32
   |        |  +--rw underlay-backup-path
   |        |  |  +--rw topology-id?    leafref
   |        |  |  +--rw path-element* [path-element-id]



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   |        |  |     +--rw path-element-id    uint32
   |        |  |     +--rw loose?             boolean
   |        |  |     +--rw (element-type)?
   |        |  |        +--:(numbered-link)
   |        |  |        |  +--rw link-ip-address?   inet:ip-address
   |        |  |        +--:(unnumbered-link)
   |        |  |        |  +--rw link-node-id?      uint32
   |        |  |        |  +--rw te-link-id?        uint32
   |        |  |        +--:(node)
   |        |  |        |  +--rw te-node-id?        uint32
   |        |  |        +--:(label)
   |        |  |           +--rw label?             uint32
   |        |  +--rw underlay-protection-type?   uint16
   |        |  +--rw underlay-trail-src
   |        |  |  +--rw topo-ref?       leafref
   |        |  |  +--rw node-ref?       leafref
   |        |  |  +--rw link-end-ref?   leafref
   |        |  +--rw underlay-trail-des
   |        |     +--rw topo-ref?       leafref
   |        |     +--rw node-ref?       leafref
   |        |     +--rw link-end-ref?   leafref
   |        +--rw ted
   |           +--rw admin-status?                       enumeration
   |           +--rw oper-status?                        enumeration
   |           +--rw area-id?                            binary
   |           +--rw performance-metric-throttle
{te-performance-metric}?
   |           |  +--rw unidirectional-delay-offset?           uint32
   |           |  +--rw measure-interval?                      uint32
   |           |  +--rw advertisement-interval?                uint32
   |           |  +--rw suppression-interval?                  uint32
   |           |  +--rw threshold-out
   |           |  |  +--rw unidirectional-delay?               uint32
   |           |  |  +--rw unidirectional-min-delay?           uint32
   |           |  |  +--rw unidirectional-max-delay?           uint32
   |           |  |  +--rw unidirectional-delay-variation?     uint32
   |           |  |  +--rw unidirectional-packet-loss?      decimal64
   |           |  |  +--rw unidirectional-residual-bandwidth?
decimal64
   |           |  |  +--rw unidirectional-available-bandwidth?
decimal64
   |           |  |  +--rw unidirectional-utilized-bandwidth?
decimal64
   |           |  +--rw threshold-in
   |           |  |  +--rw unidirectional-delay?               uint32
   |           |  |  +--rw unidirectional-min-delay?           uint32
   |           |  |  +--rw unidirectional-max-delay?           uint32
   |           |  |  +--rw unidirectional-delay-variation?     uint32



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   |           |  |  +--rw unidirectional-packet-loss?      decimal64
   |           |  |  +--rw unidirectional-residual-bandwidth?
decimal64
   |           |  |  +--rw unidirectional-available-bandwidth?
decimal64
   |           |  |  +--rw unidirectional-utilized-bandwidth?
decimal64
   |           |  +--rw threshold-accelerated-advertisement
   |           |     +--rw unidirectional-delay?               uint32
   |           |     +--rw unidirectional-min-delay?           uint32
   |           |     +--rw unidirectional-max-delay?           uint32
   |           |     +--rw unidirectional-delay-variation?     uint32
   |           |     +--rw unidirectional-packet-loss?      decimal64
   |           |     +--rw unidirectional-residual-bandwidth?
decimal64
   |           |     +--rw unidirectional-available-bandwidth?
decimal64
   |           |     +--rw unidirectional-utilized-bandwidth?
decimal64
   |           +--rw information-source?                 enumeration
   |           +--rw credibility-preference?             uint16
   |           +--rw link-index?                         uint64
   |           +--rw administrative-group* [sequence]
   |           |  +--rw sequence      uint32
   |           |  +--rw ag-element?   uint32
   |           +--rw max-link-bandwidth?                 decimal64
   |           +--rw max-resv-link-bandwidth?            decimal64
   |           +--rw unreserved-bandwidth* [priority]
   |           |  +--rw priority     uint8
   |           |  +--rw bandwidth?   decimal64
   |           +--rw te-default-metric?                  uint32
   |           +--rw performance-metric {te-performance-metric}?
   |           |  +--rw measurement
   |           |  |  +--rw unidirectional-delay?               uint32
   |           |  |  +--rw unidirectional-min-delay?           uint32
   |           |  |  +--rw unidirectional-max-delay?           uint32
   |           |  |  +--rw unidirectional-delay-variation?     uint32
   |           |  |  +--rw unidirectional-packet-loss?      decimal64
   |           |  |  +--rw unidirectional-residual-bandwidth?
decimal64
   |           |  |  +--rw unidirectional-available-bandwidth?
decimal64
   |           |  |  +--rw unidirectional-utilized-bandwidth?
decimal64
   |           |  +--rw normality
   |           |     +--rw unidirectional-delay?
performance-metric-normality
   |           |     +--rw unidirectional-min-delay?



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performance-metric-normality
   |           |     +--rw unidirectional-max-delay?
performance-metric-normality
   |           |     +--rw unidirectional-delay-variation?
performance-metric-normality
   |           |     +--rw unidirectional-packet-loss?
performance-metric-normality
   |           |     +--rw unidirectional-residual-bandwidth?
performance-metric-normality
   |           |     +--rw unidirectional-available-bandwidth?
performance-metric-normality
   |           |     +--rw unidirectional-utilized-bandwidth?
performance-metric-normality
   |           +--rw link-protection-type?               enumeration
   |           +--rw interface-switching-capabilities*
[switching-capability]
   |           |  +--rw switching-capability
ted:switching-capabilities
   |           |  +--rw encoding?                   ted:encoding-type
   |           |  +--rw max-lsp-bandwidth* [priority]
   |           |  |  +--rw priority     uint8
   |           |  |  +--rw bandwidth?   decimal64
   |           |  +--rw packet-switch-capable
   |           |  |  +--rw minimum-lsp-bandwidth?   decimal64
   |           |  |  +--rw interface-mtu?           uint16
   |           |  +--rw time-division-multiplex-capable
   |           |     +--rw minimum-lsp-bandwidth?   decimal64
   |           |     +--rw indication?              enumeration
   |           +--rw srlg
   |           |  +--rw srlg-values* [srlg-value]
   |           |     +--rw srlg-value    uint32
   |           +--rw alt-information-sources* [information-source]
   |              +--rw information-source                enumeration
   |              +--rw credibility-preference?             uint16
   |              +--rw link-index?                         uint64
   |              +--rw administrative-group* [sequence]
   |              |  +--rw sequence      uint32
   |              |  +--rw ag-element?   uint32
   |              +--rw max-link-bandwidth?                 decimal64
   |              +--rw max-resv-link-bandwidth?            decimal64
   |              +--rw unreserved-bandwidth* [priority]
   |              |  +--rw priority     uint8
   |              |  +--rw bandwidth?   decimal64
   |              +--rw te-default-metric?                     uint32
   |              +--rw performance-metric {te-performance-metric}?
   |              |  +--rw measurement
   |              |  |  +--rw unidirectional-delay?            uint32
   |              |  |  +--rw unidirectional-min-delay?        uint32



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   |              |  |  +--rw unidirectional-max-delay?        uint32
   |              |  |  +--rw unidirectional-delay-variation?  uint32
   |              |  |  +--rw unidirectional-packet-loss?   decimal64
   |              |  |  +--rw unidirectional-residual-bandwidth?
decimal64
   |              |  |  +--rw unidirectional-available-bandwidth?
decimal64
   |              |  |  +--rw unidirectional-utilized-bandwidth?
decimal64
   |              |  +--rw normality
   |              |     +--rw unidirectional-delay?
performance-metric-normality
   |              |     +--rw unidirectional-min-delay?
performance-metric-normality
   |              |     +--rw unidirectional-max-delay?
performance-metric-normality
   |              |     +--rw unidirectional-delay-variation?
performance-metric-normality
   |              |     +--rw unidirectional-packet-loss?
performance-metric-normality
   |              |     +--rw unidirectional-residual-bandwidth?
performance-metric-normality
   |              |     +--rw unidirectional-available-bandwidth?
performance-metric-normality
   |              |     +--rw unidirectional-utilized-bandwidth?
performance-metric-normality
   |              +--rw link-protection-type?             enumeration
   |              +--rw interface-switching-capabilities*
[switching-capability]
   |              |  +--rw switching-capability
ted:switching-capabilities
   |              |  +--rw encoding?                ted:encoding-type
   |              |  +--rw max-lsp-bandwidth* [priority]
   |              |  |  +--rw priority     uint8
   |              |  |  +--rw bandwidth?   decimal64
   |              |  +--rw packet-switch-capable
   |              |  |  +--rw minimum-lsp-bandwidth?   decimal64
   |              |  |  +--rw interface-mtu?           uint16
   |              |  +--rw time-division-multiplex-capable
   |              |     +--rw minimum-lsp-bandwidth?   decimal64
   |              |     +--rw indication?              enumeration
   |              +--rw srlg
   |                 +--rw srlg-values* [srlg-value]
   |                    +--rw srlg-value    uint32
   +--ro te-topologies-state
      +--ro topology* [te-topology-id]
         +--ro te-topology-id     te-topology-id
         +--ro server-provided?   boolean



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         +--ro topology-types
         |  +--ro te-topology!
         +--ro node* [te-node-id]
         |  +--ro te-node-id                  te-node-id
         |  +--ro te-node-template?           leafref
         |  +--ro te-node-attributes
         |  |  +--ro schedules* [schedule-id]
         |  |  |  +--ro schedule-id          uint32
         |  |  |  +--ro start?               yang:date-and-time
         |  |  |  +--ro schedule-duration?   string
         |  |  |  +--ro repeat-interval?     string
         |  |  +--ro name?                  inet:domain-name
         |  |  +--ro signaling-address*     inet:ip-address
         |  |  +--ro flag*                  flag-type
         |  |  +--ro is-abstract?           boolean
         |  |  +--ro underlay-topology?     leafref
{te-topology-hierarchy}?
         |  |  +--ro te-link* [te-link-id]
         |  |  |  +--ro te-link-id         te-link-id
         |  |  |  +--ro (stack-level)?
         |  |  |     +--:(bundle)
         |  |  |     |  +--ro bundled-links
         |  |  |     |     +--ro bundled-link* [sequence]
         |  |  |     |        +--ro sequence       uint32
         |  |  |     |        +--ro te-link-ref?   leafref
         |  |  |     +--:(component)
         |  |  |        +--ro component-links
         |  |  |           +--ro component-link* [sequence]
         |  |  |              +--ro sequence              uint32
         |  |  |              +--ro component-link-ref?   leafref
         |  |  +--ro connectivity-matrix* [id]
         |  |  |  +--ro id            uint32
         |  |  |  +--ro from-link
         |  |  |  |  +--ro topo-ref?       leafref
         |  |  |  |  +--ro node-ref?       leafref
         |  |  |  |  +--ro link-end-ref?   leafref
         |  |  |  +--ro to-link
         |  |  |  |  +--ro topo-ref?       leafref
         |  |  |  |  +--ro node-ref?       leafref
         |  |  |  |  +--ro link-end-ref?   leafref
         |  |  |  +--ro is-allowed?   boolean
         |  |  +--ro ted
         |  |     +--ro te-router-id-ipv4?    inet:ipv4-address
         |  |     +--ro te-router-id-ipv6?    inet:ipv6-address
         |  |     +--ro ipv4-local-address* [ipv4-prefix]
         |  |     |  +--ro ipv4-prefix    inet:ipv4-prefix
         |  |     +--ro ipv6-local-address* [ipv6-prefix]
         |  |     |  +--ro ipv6-prefix      inet:ipv6-prefix



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         |  |     |  +--ro prefix-option?   uint8
         |  |     +--ro pcc-capabilities?     pcc-capabilities
         |  +--ro te-node-state-attributes
         |     +--ro information-source?       enumeration
         |     +--ro credibility-preference?   uint16
         +--ro link* [source-te-node-id source-te-link-id
                      dest-te-node-id dest-te-link-id]
            +--ro source-te-node-id           leafref
            +--ro source-te-link-id           leafref
            +--ro dest-te-node-id             leafref
            +--ro dest-te-link-id             leafref
            +--ro te-link-template?           leafref
            +--ro te-link-attributes
            |  +--ro schedules* [schedule-id]
            |  |  +--ro schedule-id          uint32
            |  |  +--ro start?               yang:date-and-time
            |  |  +--ro schedule-duration?   string
            |  |  +--ro repeat-interval?     string
            |  +--ro name?          string
            |  +--ro flag*          flag-type
            |  +--ro is-abstract?   boolean
            |  +--ro underlay! {te-topology-hierarchy}?
            |  |  +--ro underlay-path
            |  |  |  +--ro topology-id?    leafref
            |  |  |  +--ro path-element* [path-element-id]
            |  |  |     +--ro path-element-id    uint32
            |  |  |     +--ro loose?             boolean
            |  |  |     +--ro (element-type)?
            |  |  |        +--:(numbered-link)
            |  |  |        |  +--ro link-ip-address?  inet:ip-address
            |  |  |        +--:(unnumbered-link)
            |  |  |        |  +--ro link-node-id?      uint32
            |  |  |        |  +--ro te-link-id?        uint32
            |  |  |        +--:(node)
            |  |  |        |  +--ro te-node-id?        uint32
            |  |  |        +--:(label)
            |  |  |           +--ro label?             uint32
            |  |  +--ro underlay-backup-path
            |  |  |  +--ro topology-id?    leafref
            |  |  |  +--ro path-element* [path-element-id]
            |  |  |     +--ro path-element-id    uint32
            |  |  |     +--ro loose?             boolean
            |  |  |     +--ro (element-type)?
            |  |  |        +--:(numbered-link)
            |  |  |        |  +--ro link-ip-address?  inet:ip-address
            |  |  |        +--:(unnumbered-link)
            |  |  |        |  +--ro link-node-id?      uint32
            |  |  |        |  +--ro te-link-id?        uint32



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            |  |  |        +--:(node)
            |  |  |        |  +--ro te-node-id?        uint32
            |  |  |        +--:(label)
            |  |  |           +--ro label?             uint32
            |  |  +--ro underlay-protection-type?   uint16
            |  |  +--ro underlay-trail-src
            |  |  |  +--ro topo-ref?       leafref
            |  |  |  +--ro node-ref?       leafref
            |  |  |  +--ro link-end-ref?   leafref
            |  |  +--ro underlay-trail-des
            |  |  |  +--ro topo-ref?       leafref
            |  |  |  +--ro node-ref?       leafref
            |  |  |  +--ro link-end-ref?   leafref
            |  |  +--ro dynamic?                    boolean
            |  |  +--ro committed?                  boolean
            |  +--ro ted
            |     +--ro admin-status?                     enumeration
            |     +--ro oper-status?                      enumeration
            |     +--ro area-id?                          binary
            |     +--ro performance-metric-throttle {te-performance-metric}?
            |     |  +--ro unidirectional-delay-offset?        uint32
            |     |  +--ro measure-interval?                   uint32
            |     |  +--ro advertisement-interval?             uint32
            |     |  +--ro suppression-interval?               uint32
            |     |  +--ro threshold-out
            |     |  |  +--ro unidirectional-delay?            uint32
            |     |  |  +--ro unidirectional-min-delay?        uint32
            |     |  |  +--ro unidirectional-max-delay?        uint32
            |     |  |  +--ro unidirectional-delay-variation?  uint32
            |     |  |  +--ro unidirectional-packet-loss?
decimal64
            |     |  |  +--ro unidirectional-residual-bandwidth?
decimal64
            |     |  |  +--ro unidirectional-available-bandwidth?
decimal64
            |     |  |  +--ro unidirectional-utilized-bandwidth?
decimal64
            |     |  +--ro threshold-in
            |     |  |  +--ro unidirectional-delay?            uint32
            |     |  |  +--ro unidirectional-min-delay?        uint32
            |     |  |  +--ro unidirectional-max-delay?        uint32
            |     |  |  +--ro unidirectional-delay-variation?  uint32
            |     |  |  +--ro unidirectional-packet-loss?   decimal64
            |     |  |  +--ro unidirectional-residual-bandwidth?
decimal64
            |     |  |  +--ro unidirectional-available-bandwidth?
decimal64
            |     |  |  +--ro unidirectional-utilized-bandwidth?



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decimal64
            |     |  +--ro threshold-accelerated-advertisement
            |     |     +--ro unidirectional-delay?            uint32
            |     |     +--ro unidirectional-min-delay?        uint32
            |     |     +--ro unidirectional-max-delay?        uint32
            |     |     +--ro unidirectional-delay-variation?  uint32
            |     |     +--ro unidirectional-packet-loss?   decimal64
            |     |     +--ro unidirectional-residual-bandwidth?
decimal64
            |     |     +--ro unidirectional-available-bandwidth?
decimal64
            |     |     +--ro unidirectional-utilized-bandwidth?
decimal64
            |     +--ro information-source?               enumeration
            |     +--ro credibility-preference?           uint16
            |     +--ro link-index?                       uint64
            |     +--ro administrative-group* [sequence]
            |     |  +--ro sequence      uint32
            |     |  +--ro ag-element?   uint32
            |     +--ro max-link-bandwidth?                 decimal64
            |     +--ro max-resv-link-bandwidth?            decimal64
            |     +--ro unreserved-bandwidth* [priority]
            |     |  +--ro priority     uint8
            |     |  +--ro bandwidth?   decimal64
            |     +--ro te-default-metric?                  uint32
            |     +--ro performance-metric {te-performance-metric}?
            |     |  +--ro measurement
            |     |  |  +--ro unidirectional-delay?            uint32
            |     |  |  +--ro unidirectional-min-delay?        uint32
            |     |  |  +--ro unidirectional-max-delay?        uint32
            |     |  |  +--ro unidirectional-delay-variation?  uint32
            |     |  |  +--ro unidirectional-packet-loss?   decimal64
            |     |  |  +--ro unidirectional-residual-bandwidth?
decimal64
            |     |  |  +--ro unidirectional-available-bandwidth?
decimal64
            |     |  |  +--ro unidirectional-utilized-bandwidth?
decimal64
            |     |  +--ro normality
            |     |     +--ro unidirectional-delay?
performance-metric-normality
            |     |     +--ro unidirectional-min-delay?
performance-metric-normality
            |     |     +--ro unidirectional-max-delay?
performance-metric-normality
            |     |     +--ro unidirectional-delay-variation?
performance-metric-normality
            |     |     +--ro unidirectional-packet-loss?



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performance-metric-normality
            |     |     +--ro unidirectional-residual-bandwidth?
performance-metric-normality
            |     |     +--ro unidirectional-available-bandwidth?
performance-metric-normality
            |     |     +--ro unidirectional-utilized-bandwidth?
performance-metric-normality
            |     +--ro link-protection-type?             enumeration
            |     +--ro interface-switching-capabilities*
[switching-capability]
            |     |  +--ro switching-capability
ted:switching-capabilities
            |     |  +--ro encoding?
ted:encoding-type
            |     |  +--ro max-lsp-bandwidth* [priority]
            |     |  |  +--ro priority     uint8
            |     |  |  +--ro bandwidth?   decimal64
            |     |  +--ro packet-switch-capable
            |     |  |  +--ro minimum-lsp-bandwidth?   decimal64
            |     |  |  +--ro interface-mtu?           uint16
            |     |  +--ro time-division-multiplex-capable
            |     |     +--ro minimum-lsp-bandwidth?   decimal64
            |     |     +--ro indication?              enumeration
            |     +--ro srlg
            |     |  +--ro srlg-values* [srlg-value]
            |     |     +--ro srlg-value    uint32
            |     +--ro alt-information-sources* [information-source]
            |        +--ro information-source             enumeration
            |        +--ro credibility-preference?             uint16
            |        +--ro link-index?                         uint64
            |        +--ro administrative-group* [sequence]
            |        |  +--ro sequence      uint32
            |        |  +--ro ag-element?   uint32
            |        +--ro max-link-bandwidth?              decimal64
            |        +--ro max-resv-link-bandwidth?         decimal64
            |        +--ro unreserved-bandwidth* [priority]
            |        |  +--ro priority     uint8
            |        |  +--ro bandwidth?   decimal64
            |        +--ro te-default-metric?                  uint32
            |        +--ro performance-metric
{te-performance-metric}?
            |        |  +--ro measurement
            |        |  |  +--ro unidirectional-delay?         uint32
            |        |  |  +--ro unidirectional-min-delay?     uint32
            |        |  |  +--ro unidirectional-max-delay?     uint32
            |        |  |  +--ro unidirectional-delay-variation?
uint32
            |        |  |  +--ro unidirectional-packet-loss?



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decimal64
            |        |  |  +--ro unidirectional-residual-bandwidth?
decimal64
            |        |  |  +--ro unidirectional-available-bandwidth?
decimal64
            |        |  |  +--ro unidirectional-utilized-bandwidth?
decimal64
            |        |  +--ro normality
            |        |     +--ro unidirectional-delay?
performance-metric-normality
            |        |     +--ro unidirectional-min-delay?
performance-metric-normality
            |        |     +--ro unidirectional-max-delay?
performance-metric-normality
            |        |     +--ro unidirectional-delay-variation?
performance-metric-normality
            |        |     +--ro unidirectional-packet-loss?
performance-metric-normality
            |        |     +--ro unidirectional-residual-bandwidth?
performance-metric-normality
            |        |     +--ro unidirectional-available-bandwidth?
performance-metric-normality
            |        |     +--ro unidirectional-utilized-bandwidth?
performance-metric-normality
            |        +--ro link-protection-type?          enumeration
            |        +--ro interface-switching-capabilities*
[switching-capability]
            |        |  +--ro switching-capability
ted:switching-capabilities
            |        |  +--ro encoding?             ted:encoding-type
            |        |  +--ro max-lsp-bandwidth* [priority]
            |        |  |  +--ro priority     uint8
            |        |  |  +--ro bandwidth?   decimal64
            |        |  +--ro packet-switch-capable
            |        |  |  +--ro minimum-lsp-bandwidth?   decimal64
            |        |  |  +--ro interface-mtu?           uint16
            |        |  +--ro time-division-multiplex-capable
            |        |     +--ro minimum-lsp-bandwidth?   decimal64
            |        |     +--ro indication?              enumeration
            |        +--ro srlg
            |           +--ro srlg-values* [srlg-value]
            |              +--ro srlg-value    uint32
            +--ro te-link-state-attributes
               +--ro information-source?       enumeration
               +--ro credibility-preference?   uint16
notifications:
   +---n te-node-event
   |  +--ro event-type?           te-topology-event-type



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   |  +--ro topo-ref?             leafref
   |  +--ro node-ref?             leafref
   |  +--ro te-topology!
   |  +--ro te-node-attributes
   |     +--ro schedules* [schedule-id]
   |     |  +--ro schedule-id          uint32
   |     |  +--ro start?               yang:date-and-time
   |     |  +--ro schedule-duration?   string
   |     |  +--ro repeat-interval?     string
   |     +--ro name?                  inet:domain-name
   |     +--ro signaling-address*     inet:ip-address
   |     +--ro flag*                  flag-type
   |     +--ro is-abstract?           boolean
   |     +--ro underlay-topology?    leafref {te-topology-hierarchy}?
   |     +--ro te-link* [te-link-id]
   |     |  +--ro te-link-id         te-link-id
   |     |  +--ro (stack-level)?
   |     |     +--:(bundle)
   |     |     |  +--ro bundled-links
   |     |     |     +--ro bundled-link* [sequence]
   |     |     |        +--ro sequence       uint32
   |     |     |        +--ro te-link-ref?   leafref
   |     |     +--:(component)
   |     |        +--ro component-links
   |     |           +--ro component-link* [sequence]
   |     |              +--ro sequence              uint32
   |     |              +--ro component-link-ref?   leafref
   |     +--ro connectivity-matrix* [id]
   |     |  +--ro id            uint32
   |     |  +--ro from-link
   |     |  |  +--ro topo-ref?       leafref
   |     |  |  +--ro node-ref?       leafref
   |     |  |  +--ro link-end-ref?   leafref
   |     |  +--ro to-link
   |     |  |  +--ro topo-ref?       leafref
   |     |  |  +--ro node-ref?       leafref
   |     |  |  +--ro link-end-ref?   leafref
   |     |  +--ro is-allowed?   boolean
   |     +--ro ted
   |        +--ro te-router-id-ipv4?    inet:ipv4-address
   |        +--ro te-router-id-ipv6?    inet:ipv6-address
   |        +--ro ipv4-local-address* [ipv4-prefix]
   |        |  +--ro ipv4-prefix    inet:ipv4-prefix
   |        +--ro ipv6-local-address* [ipv6-prefix]
   |        |  +--ro ipv6-prefix      inet:ipv6-prefix
   |        |  +--ro prefix-option?   uint8
   |        +--ro pcc-capabilities?     pcc-capabilities
   +---n te-link-event



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      +--ro event-type?              te-topology-event-type
      +--ro topo-ref?                leafref
      +--ro source-te-node-id-ref?   leafref
      +--ro source-te-link-id-ref?   leafref
      +--ro dest-te-node-id-ref?     leafref
      +--ro dest-te-link-id-ref?     leafref
      +--ro te-topology!
      +--ro te-link-attributes
         +--ro schedules* [schedule-id]
         |  +--ro schedule-id          uint32
         |  +--ro start?               yang:date-and-time
         |  +--ro schedule-duration?   string
         |  +--ro repeat-interval?     string
         +--ro name?          string
         +--ro flag*          flag-type
         +--ro is-abstract?   boolean
         +--ro underlay! {te-topology-hierarchy}?
         |  +--ro underlay-path
         |  |  +--ro topology-id?    leafref
         |  |  +--ro path-element* [path-element-id]
         |  |     +--ro path-element-id    uint32
         |  |     +--ro loose?             boolean
         |  |     +--ro (element-type)?
         |  |        +--:(numbered-link)
         |  |        |  +--ro link-ip-address?   inet:ip-address
         |  |        +--:(unnumbered-link)
         |  |        |  +--ro link-node-id?      uint32
         |  |        |  +--ro te-link-id?        uint32
         |  |        +--:(node)
         |  |        |  +--ro te-node-id?        uint32
         |  |        +--:(label)
         |  |           +--ro label?             uint32
         |  +--ro underlay-backup-path
         |  |  +--ro topology-id?    leafref
         |  |  +--ro path-element* [path-element-id]
         |  |     +--ro path-element-id    uint32
         |  |     +--ro loose?             boolean
         |  |     +--ro (element-type)?
         |  |        +--:(numbered-link)
         |  |        |  +--ro link-ip-address?   inet:ip-address
         |  |        +--:(unnumbered-link)
         |  |        |  +--ro link-node-id?      uint32
         |  |        |  +--ro te-link-id?        uint32
         |  |        +--:(node)
         |  |        |  +--ro te-node-id?        uint32
         |  |        +--:(label)
         |  |           +--ro label?             uint32
         |  +--ro underlay-protection-type?   uint16



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         |  +--ro underlay-trail-src
         |  |  +--ro topo-ref?       leafref
         |  |  +--ro node-ref?       leafref
         |  |  +--ro link-end-ref?   leafref
         |  +--ro underlay-trail-des
         |  |  +--ro topo-ref?       leafref
         |  |  +--ro node-ref?       leafref
         |  |  +--ro link-end-ref?   leafref
         |  +--ro dynamic?                    boolean
         |  +--ro committed?                  boolean
         +--ro ted
            +--ro admin-status?                       enumeration
            +--ro oper-status?                        enumeration
            +--ro area-id?                            binary
            +--ro performance-metric-throttle{te-performance-metric}?
            |  +--ro unidirectional-delay-offset?           uint32
            |  +--ro measure-interval?                      uint32
            |  +--ro advertisement-interval?                uint32
            |  +--ro suppression-interval?                  uint32
            |  +--ro threshold-out
            |  |  +--ro unidirectional-delay?                 uint32
            |  |  +--ro unidirectional-min-delay?             uint32
            |  |  +--ro unidirectional-max-delay?             uint32
            |  |  +--ro unidirectional-delay-variation?       uint32
            |  |  +--ro unidirectional-packet-loss?
decimal64
            |  |  +--ro unidirectional-residual-bandwidth?
decimal64
            |  |  +--ro unidirectional-available-bandwidth?
decimal64
            |  |  +--ro unidirectional-utilized-bandwidth?
decimal64
            |  +--ro threshold-in
            |  |  +--ro unidirectional-delay?                 uint32
            |  |  +--ro unidirectional-min-delay?             uint32
            |  |  +--ro unidirectional-max-delay?             uint32
            |  |  +--ro unidirectional-delay-variation?       uint32
            |  |  +--ro unidirectional-packet-loss?         decimal64
            |  |  +--ro unidirectional-residual-bandwidth?  decimal64
            |  |  +--ro unidirectional-available-bandwidth? decimal64
            |  |  +--ro unidirectional-utilized-bandwidth?  decimal64
            |  +--ro threshold-accelerated-advertisement
            |     +--ro unidirectional-delay?                 uint32
            |     +--ro unidirectional-min-delay?             uint32
            |     +--ro unidirectional-max-delay?             uint32
            |     +--ro unidirectional-delay-variation?       uint32
            |     +--ro unidirectional-packet-loss?         decimal64
            |     +--ro unidirectional-residual-bandwidth?  decimal64



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            |     +--ro unidirectional-available-bandwidth? decimal64
            |     +--ro unidirectional-utilized-bandwidth?  decimal64
            +--ro information-source?                 enumeration
            +--ro credibility-preference?             uint16
            +--ro link-index?                         uint64
            +--ro administrative-group* [sequence]
            |  +--ro sequence      uint32
            |  +--ro ag-element?   uint32
            +--ro max-link-bandwidth?                 decimal64
            +--ro max-resv-link-bandwidth?            decimal64
            +--ro unreserved-bandwidth* [priority]
            |  +--ro priority     uint8
            |  +--ro bandwidth?   decimal64
            +--ro te-default-metric?                  uint32
            +--ro performance-metric {te-performance-metric}?
            |  +--ro measurement
            |  |  +--ro unidirectional-delay?                 uint32
            |  |  +--ro unidirectional-min-delay?             uint32
            |  |  +--ro unidirectional-max-delay?             uint32
            |  |  +--ro unidirectional-delay-variation?       uint32
            |  |  +--ro unidirectional-packet-loss?         decimal64
            |  |  +--ro unidirectional-residual-bandwidth?  decimal64
            |  |  +--ro unidirectional-available-bandwidth? decimal64
            |  |  +--ro unidirectional-utilized-bandwidth?  decimal64
            |  +--ro normality
            |     +--ro unidirectional-delay?
performance-metric-normality
            |     +--ro unidirectional-min-delay?
performance-metric-normality
            |     +--ro unidirectional-max-delay?
performance-metric-normality
            |     +--ro unidirectional-delay-variation?
performance-metric-normality
            |     +--ro unidirectional-packet-loss?
performance-metric-normality
            |     +--ro unidirectional-residual-bandwidth?
performance-metric-normality
            |     +--ro unidirectional-available-bandwidth?
performance-metric-normality
            |     +--ro unidirectional-utilized-bandwidth?
performance-metric-normality
            +--ro link-protection-type?               enumeration
            +--ro interface-switching-capabilities*
[switching-capability]
            |  +--ro switching-capability  ted:switching-capabilities
            |  +--ro encoding?             ted:encoding-type
            |  +--ro max-lsp-bandwidth* [priority]
            |  |  +--ro priority     uint8



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            |  |  +--ro bandwidth?   decimal64
            |  +--ro packet-switch-capable
            |  |  +--ro minimum-lsp-bandwidth?   decimal64
            |  |  +--ro interface-mtu?           uint16
            |  +--ro time-division-multiplex-capable
            |     +--ro minimum-lsp-bandwidth?   decimal64
            |     +--ro indication?              enumeration
            +--ro srlg
            |  +--ro srlg-values* [srlg-value]
            |     +--ro srlg-value    uint32
            +--ro alt-information-sources* [information-source]
               +--ro information-source                  enumeration
               +--ro credibility-preference?             uint16
               +--ro link-index?                         uint64
               +--ro administrative-group* [sequence]
               |  +--ro sequence      uint32
               |  +--ro ag-element?   uint32
               +--ro max-link-bandwidth?                 decimal64
               +--ro max-resv-link-bandwidth?            decimal64
               +--ro unreserved-bandwidth* [priority]
               |  +--ro priority     uint8
               |  +--ro bandwidth?   decimal64
               +--ro te-default-metric?                  uint32
               +--ro performance-metric {te-performance-metric}?
               |  +--ro measurement
               |  |  +--ro unidirectional-delay?               uint32
               |  |  +--ro unidirectional-min-delay?           uint32
               |  |  +--ro unidirectional-max-delay?           uint32
               |  |  +--ro unidirectional-delay-variation?     uint32
               |  |  +--ro unidirectional-packet-loss?      decimal64
               |  |  +--ro unidirectional-residual-bandwidth?
decimal64
               |  |  +--ro unidirectional-available-bandwidth?
decimal64
               |  |  +--ro unidirectional-utilized-bandwidth?
decimal64
               |  +--ro normality
               |     +--ro unidirectional-delay?
performance-metric-normality
               |     +--ro unidirectional-min-delay?
performance-metric-normality
               |     +--ro unidirectional-max-delay?
performance-metric-normality
               |     +--ro unidirectional-delay-variation?
performance-metric-normality
               |     +--ro unidirectional-packet-loss?
performance-metric-normality
               |     +--ro unidirectional-residual-bandwidth?



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performance-metric-normality
               |     +--ro unidirectional-available-bandwidth?
performance-metric-normality
               |     +--ro unidirectional-utilized-bandwidth?
performance-metric-normality
               +--ro link-protection-type?               enumeration
               +--ro interface-switching-capabilities*
[switching-capability]
               |  +--ro switching-capability
ted:switching-capabilities
               |  +--ro encoding?                   ted:encoding-type
               |  +--ro max-lsp-bandwidth* [priority]
               |  |  +--ro priority     uint8
               |  |  +--ro bandwidth?   decimal64
               |  +--ro packet-switch-capable
               |  |  +--ro minimum-lsp-bandwidth?   decimal64
               |  |  +--ro interface-mtu?           uint16
               |  +--ro time-division-multiplex-capable
               |     +--ro minimum-lsp-bandwidth?   decimal64
               |     +--ro indication?              enumeration
               +--ro srlg
                  +--ro srlg-values* [srlg-value]
                     +--ro srlg-value    uint32


3.1.  TE Topology Yang Module

  <CODE BEGINS> file "ietf-te-topology@2015-03-23.yang"
  module ietf-te-topology {
    yang-version 1;
    namespace "urn:ietf:params:xml:ns:yang:ietf-te-topology";
    // replace with IANA namespace when assigned

    prefix "tet";

    import ietf-yang-types {
      prefix "yang";
    }

    import ietf-inet-types {
      prefix "inet";
    }

    import ted {
      prefix "ted";
    }

    import ietf-interfaces {



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      prefix "if";
    }

    organization "TBD";
    contact "TBD";
    description "TE topology model";

    revision "2015-03-23" {
      description "Initial revision";
      reference "TBD";
    }

    /*
     * Features
     */

    feature te-topology-hierarchy {
      description
        "This feature indicates that the system allows underlay
         and/or overlay TE topology hierarchy.";
    }

    /*
     * Typedefs
     */

    typedef te-topology-id {
      type string {
        pattern '/?([a-zA-Z0-9\-_.]+)(/[a-zA-Z0-9\-_.]+)*';
      }
      description
        "An identifier for a topology.";
    }

    typedef te-template-name {
      type string {
        pattern '/?([a-zA-Z0-9\-_.]+)(/[a-zA-Z0-9\-_.]+)*';
      }
      description
        "A type for the name of a TE node template or TE link
        template.";
    }

    typedef te-node-id {
      type inet:ip-address;
      description
        "An identifier for a node in a topology.
         The identifier is represented as an IPv4 or IPv6 address.



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         The identifier SHOULD be chosen such that the same node in a
         real network topology will always be identified through the
         same identifier, even if the model is instantiated in
          separate datastores. An implementation MAY choose to capture
         semantics in the identifier, for example to indicate the type
           of node and/or the type of topology that the node is a part
         of.";
    }

    typedef te-link-id {
      type union {
        type uint32;          // Unnumbered
        type inet:ip-address; // IPv4 or IPv6 address
      }
      description
        "An identifier for a TE link on a node.
         The identifier may be opaque.
         The identifier SHOULD be chosen such that the same TP in a
         real network topology will always be identified through the
         same identifier, even if the model is instantiated in
          separate datastores. An implementation MAY choose to capture
         semantics in the identifier, for example to indicate the type
         of TP and/or the type of node and topology that the TP is a
         part of.";
    }


    typedef te-topology-event-type {
      type enumeration {
        enum "add" {
          value 0;
          description
            "A TE node or te-link has
            been added";
        }
        enum "remove" {
          value 1;
          description
            "A TE node or te-link has
            been removed";
        }
        enum "update" {
          value 2;
          description
            "A TE node or te-link has
            been updated";
        }
      }



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      description "TE  Event type for notifications";
    } // te-topology-event-type

    /*
     * Identities
     */

    identity flag-identity {
      description "Base type for flags";
    }

    identity undefined-flag {
      base "flag-identity";
      description "Undefined flag";
    }

    typedef flag-type {
      type identityref {
        base "flag-identity";
      }
      description "Type for flags";
    }

    /*
     * Groupings
     */

    grouping topo-ref {
      description
        "Grouping for an absolute reference to a topology instance.";
      leaf topo-ref {
        type leafref {
          path "/tet:te-topologies/tet:topology/tet:te-topology-id";
        }
        description
          "An absolute reference to a topology instance.";
      }
    }

    grouping link-ref {
      description
        "Grouping for an absolute reference to a link instance.";
      uses topo-ref;
      leaf source-te-node-id-ref {
        type leafref {
          path "/tet:te-topologies/tet:topology"
            +"[tet:te-topology-id = current()/../topo-ref]"
            +"/tet:link/tet:source-te-node-id";



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        }
        description
          "An absolute reference to a link instance.";
      }
      leaf source-te-link-id-ref {
        type leafref {
          path "/tet:te-topologies/tet:topology"
            +"[tet:te-topology-id = current()/../topo-ref]"
            +"/tet:link/tet:source-te-link-id";
        }
        description
          "An absolute reference to a link instance.";
      }
      leaf dest-te-node-id-ref {
        type leafref {
          path "/tet:te-topologies/tet:topology"
            +"[tet:te-topology-id = current()/../topo-ref]"
            +"/tet:link/tet:dest-te-node-id";
        }
        description
          "An absolute reference to a link instance.";
      }
      leaf dest-te-link-id-ref {
        type leafref {
          path "/tet:te-topologies/tet:topology"
            +"[tet:te-topology-id = current()/../topo-ref]"
            +"/tet:link/tet:dest-te-link-id";
        }
        description
          "An absolute reference to a link instance.";
      }
    }

    grouping node-ref {
      description
        "Grouping for an absolute reference to a node instance.";
      uses topo-ref;
      leaf node-ref {
        type leafref {
          path "/tet:te-topologies/tet:topology"
            +"[tet:te-topology-id = current()/../topo-ref]"
            +"/tet:node/tet:te-node-id";
        }
        description
          "An absolute reference to a node instance.";
      }
    }




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    grouping link-end-ref {
      description
        "Grouping for an absolute reference to a TE link end, which is
        the local representation of a TE link on a node.";
      uses node-ref;
      leaf link-end-ref {
        type leafref {
          path "/tet:te-topologies/tet:topology"
            +"[tet:te-topology-id = current()/../topo-ref]"
            +"/tet:node[tet:te-node-id = current()/../node-ref]"
            +"/tet:te-node-attributes/tet:te-link/tet:te-link-id";
        }
        description
          "Grouping for an absolute reference to a TE link end.";
      }
    }

    grouping te-topology-type {
      description
        "Identifies the TE topology type.";
      container te-topology {
        presence "indicates TE topology";
        description
          "Its presence identifies the TE topology type.";
      }
    }

    grouping te-path-element {
      description
        "A group of attributes defining an element in a TE path
        such as TE node, TE link, TE aotomic resource or label.";
      leaf loose {
        type boolean;
        description "true if the element is loose.";
      }
      choice element-type {
        description "Attributes for various element types.";
        case numbered-link {
          leaf link-ip-address {
            type inet:ip-address;
            description "IPv4 or IPv6 address.";
          }
        }
        case unnumbered-link {
          leaf link-node-id {
            type uint32;
            description
              "Node ID of the node where the link end point resides.";



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          }
          leaf te-link-id {
            type uint32;
            description "Identifies the link end point.";
          }
        }
        case node {
          leaf te-node-id {
            type uint32;
            description "Identifies the node.";
          }
        }
        case label {
          leaf label {
            type uint32;
            description "Identifies atomic TE resource or label.";
          }
        }
      }
    } // te-path-element

    grouping config-schedule-attributes {
      description
        "A list of schedules defining when a particular
         configuration takes effect.";
      list schedules {
        key "schedule-id";
        description "A list of schedule elements.";

        leaf schedule-id {
          type uint32;
          description "Identifies the schedule element.";
        }
        leaf start {
          type yang:date-and-time;
          description "Start time.";
        }
        leaf schedule-duration {
          type string {
            pattern
              'P(\d+Y)?(\d+M)?(\d+W)?(\d+D)?T(\d+H)?(\d+M)?(\d+S)?';
          }
          description "Schedule duration in ISO 8601 format.";
        }
        leaf repeat-interval {
          type string {
            pattern
              'R\d*/P(\d+Y)?(\d+M)?(\d+W)?(\d+D)?T(\d+H)?(\d+M)?'



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              + '(\d+S)?';
          }
          description "Repeat interval in ISO 8601 format.";
       }
      }
    }

    grouping information-source-attributes {
      description
        "The attributes identifying source that has provided the
        related information, and the source credibility.";
      leaf information-source {
        type enumeration {
          enum "unknown" {
            description "The source is unknown";
          }
          enum "locally-configured" {
            description "Configured TE link";
          }
          enum "ospfv2" {
            description "OSPFv2";
          }
          enum "ospfv3" {
            description "OSPFv3";
          }
          enum "isis" {
            description "ISIS";
          }
          enum "other" {
            description "Other source";
          }
        }
        description
          "Indicates the source of the information.";
      }
      leaf credibility-preference {
        type uint16;
        description
          "The preference value to calculate the traffic
          engineering database credibility value used for
          tie-break selection between different
          information-source values.
          Higher value is more preferable.";
      }
    }

    grouping te-node-attributes {
      description "Node attributes in a TE topology.";



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      container te-node-attributes {
        description "Node attributes in a TE topology.";
        uses config-schedule-attributes;
        leaf name {
          type inet:domain-name;
          description "Node name.";
        }
        leaf-list signaling-address {
          type inet:ip-address;
          description "Node signaling address.";
        }
        leaf-list flag {
          type flag-type;
          description "Node operational flags.";
        }
        leaf is-abstract {
          type boolean;
          description
            "true if the node is abstract, false when the node is
            actual.";
        }
        leaf underlay-topology {
          if-feature te-topology-hierarchy;
          type leafref {
            path "/tet:te-topologies/tet:topology/tet:te-topology-id";
          }
          description
            "When an abstract node encapsulates a topology,
             this reference points to said topology.";
        }
        list te-link {
          key "te-link-id";
          description
            "The local representation of a TE link, which
              interconnect TE nodes.";
          leaf te-link-id {
            type te-link-id;
            description
              "TE link identifier.";
          }
          choice stack-level {
            description
              "The TE link can be partitioned into bundled
                links, or component links.";
            case bundle {
              container bundled-links {
                description
                  "A set of bundled links";



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                list bundled-link {
                  key "sequence";
                  description
                    "Specify a bundled interfface that is
                      further partitioned.";
                  leaf sequence {
                    type uint32;
                    description
                      "Identify the sequence in the bundle.";
                  }
                  leaf te-link-ref {
                    type leafref {
                      path "../../../te-link-id";
                      require-instance "true";
                    }
                    description
                      "Reference to TE link on this node.";
                  }
                }
              }
            }
            case component {
              container component-links {
                description
                  "A set of component links";
                list component-link {
                  key "sequence";
                  description
                    "Specify a component interfface that is
                      sufficient to unambiguously identify the
                      appropriate resources";

                  leaf sequence {
                    type uint32;
                    description
                      "Identify the sequence in the bundle.";
                  }
                  leaf component-link-ref {
                    type leafref {
                      path "/if:interfaces/if:interface/if:name";
                      require-instance "false";
                    }
                    description
                      "Reference to component link on this
                        node.";
                  }
                }
              }



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            }
          }
        }
        list connectivity-matrix {
          key "id";
          description
            "Represents node's switching limitations, i.e. limitations
             in interconnecting network TE links across the node.";
          leaf id {
            type uint32;
            description "Identifies the connectivity-matrix entry.";
          }
          container from-link {
            uses tet:link-end-ref;
            description
              "Reference to source NTP.";
          }
          container to-link {
            uses tet:link-end-ref;
            description
              "Reference to destination NTP.";
          }
          leaf is-allowed {
            type boolean;
            description
              "true  - switching is allowed,
               false - switching is disallowed.";
          }
        }
        container ted {
          description "Includes TE node attributes.";
          uses ted:ted-node-attributes;
        }
      }
    } // te-node-attributes

    grouping te-node-state-attributes {
      description "Node state attributes in a TE topology.";
      container te-node-state-attributes {
        description "Node state attributes in a TE topology.";
        uses information-source-attributes;
      }
    } // te-node-state-attributes

    grouping te-link-underlay-attributes {
      description "Attributes for  te-link underlay.";
      container underlay-path {
        description



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          "The service path on the underlay topology that
           supports this link.";
        leaf topology-id {
          type leafref {
            path "/tet:te-topologies/tet:topology/tet:te-topology-id";
            require-instance false;
          }
          description
            "Identifies the topology where the path belongs.";
        }
        list path-element {
          key "path-element-id";
          description
            "A list of path elements describing the service path";
          leaf path-element-id {
            type uint32;
            description "To identify the element in a path.";
          }
          uses te-path-element;
        }
      } // underlay-path
      container underlay-backup-path {
        description
          "The backup service path on the underlay topology that
           supports this link.";
        leaf topology-id {
          type leafref {
            path "/tet:te-topologies/tet:topology/tet:te-topology-id";
            require-instance false;
          }
          description
            "Identifies the topology where the path belongs.";
        }
        list path-element {
          key "path-element-id";
          description
            "A list of path elements describing the backup service
             path";
          leaf path-element-id {
            type uint32;
            description "To identify the element in a path.";
          }
          uses te-path-element;
        }
      } // underlay-backup-path
      leaf underlay-protection-type {
        type uint16;
        description



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          "Underlay protection type desired for this link";
      }
      container underlay-trail-src {
        uses tet:link-end-ref;
        description
          "Source TE link of the underlay trail.";
      }
      container underlay-trail-des {
        uses tet:link-end-ref;
        description
          "Destination TE link of the underlay trail.";
      }
    } // te-link-underlay-attributes

    grouping te-link-state-underlay-attributes {
      description "State attributes for te-link underlay.";
      leaf dynamic {
        type boolean;
        description
          "true if the underlay is dynamically created.";
      }
      leaf committed {
        type boolean;
        description
          "true if the underlay is committed.";
      }
    } // te-link-state-underlay-attributes

    grouping te-link-attributes {
      description
        "Link attributes in a TE topology.";
      container te-link-attributes {
        description "Link attributes in a TE topology.";
        uses config-schedule-attributes;
        leaf name {
          type string;
          description "Link Name";
        }
        leaf-list flag {
          type flag-type;
          description "Link flags";
        }
        leaf is-abstract {
          type boolean;
          description "true if the link is abstract.";
        }
        container underlay {
          if-feature te-topology-hierarchy;



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          presence
            "Indicates the underlay exists for this link.";
          description "State of the underlay of this link.";

          uses te-link-underlay-attributes;
        } // underlay
        container ted {
          description "Includes TE link attributes.";
          uses ted:ted-link-attributes;
        }
      }
    } // te-link-attributes

    grouping te-link-state-attributes {
      description
        "Link state attributes in a TE topology.";
      container te-link-state-attributes {
        description "Link state attributes in a TE topology.";
        uses information-source-attributes;
      }
    } // te-link-state-attributes

    /*
     * Configuration data nodes
     */

    container te-topologies {
      description
        "This container acts as the top-level data element of
         configuration data.";
      list topology {
        key "te-topology-id";
        description
          "This is the model of an abstract topology. A topology
          contains nodes and links. Each topology MUST be identified
          by a unique te-topology-id for reason that a network could
          contain many topologies.";
        leaf te-topology-id {
          type te-topology-id;
          description
            "It is presumed that a datastore will contain many
            topologies. To distinguish between topologies it is
            vital to have UNIQUE topology identifiers.";
        }
        container topology-types {
          description
            "This container is used to identify the type, or types (as
            a topology can support several types simultaneously), of



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            the topology.
            Topology types are the subject of several integrity
            constraints that an implementing server can validate in
            order to maintain integrity of the datastore.
            Topology types are indicated through separate data nodes;
            the set of topology types is expected to increase over
            time.
            To add support for a new topology, an augmenting module
            needs to augment this container with a new empty optional
            container to indicate the new topology type.
            The use of a container allows to indicate a
            subcategorization of topology types.
            The container SHALL NOT be augmented with any data nodes
            that serve a purpose other than identifying a particular
            topology type.";
          uses te-topology-type; // Defines the TE topology type.
        }
        list node {
          key "te-node-id";
          leaf te-node-id {
            type te-node-id;
            description
              "The identifier of a node in the topology.
              A node is specific to a topology to which it belongs.";
          }
          description
            "The list of network nodes defined for the topology.";
          leaf te-node-template {
            type leafref {
              path "/te-topologies/node-template/name";
            }
            description
              "The reference to a TE node template.";
          }
          uses te-node-attributes;
        }
        list link {
          key "source-te-node-id source-te-link-id "
            + "dest-te-node-id dest-te-link-id";
          leaf source-te-node-id {
            type leafref {
              path "../../node/te-node-id";
            }
            mandatory true;
            description
              "Source node identifier, must be in same topology.";
          }
          leaf source-te-link-id {



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            type leafref {
              path "../../node[te-node-id = "
                + "current()/../source-te-node-id]/"
                + "te-node-attributes/te-link/te-link-id";
            }
            mandatory true;
            description
              "Source TE link identifier, must be in same topology.";
          }
          leaf dest-te-node-id {
            type leafref {
              path "../../node/te-node-id";
            }
            mandatory true;
            description
              "Destination node identifier, must be in the same
              topology.";
          }
          leaf dest-te-link-id {
            type leafref {
              path "../../node[te-node-id = "
                + "current()/../dest-te-node-id]/"
                + "te-node-attributes/te-link/te-link-id";
            }
            mandatory true;
            description
              "Destination TE link identifier, must be in same
              topology.";
          }
          description
            "TE link is a logical construct that represents a way
            to group/map information about certain physical
            resources (and their properties) that interconnect TE
            nodes.
            A Network Link connects a by Local (Source) node and
            a Remote (Destination) Network Nodes via a set of the
            nodes' TE links.
            As it is possible to have several links between the
            same source and destination nodes, and as a link
            could potentially be re-homed, to ensure that we
            would always know to distinguish between
            links, every link is identified by a dedicated link
            identifier.
            Note that a link models a point-to-point link, not a
            multipoint link.";
          leaf te-link-template {
            type leafref {
              path "/te-topologies/link-template/name";



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            }
            description
              "The reference to a TE link template.";
          }
          uses te-link-attributes;
        } // link
      } // topology

      list node-template {
        key "name";
        leaf name {
          type te-template-name;
          description
            "The name to identify a TE node template.";
        }
        description
          "The list of TE node templates used to define sharable
          and reusable TE node attributes.";
        uses te-node-attributes;
      } // node

      list link-template {
        key "name";
        leaf name {
          type te-template-name;
          description
            "The name to identify a TE link template.";
        }
        description
          "The list of TE link templates used to define sharable
          and reusable TE link attributes.";
        uses te-link-attributes;
      } // link
    } // te-topologies

    /*
     * Operational state data nodes
     */

    container te-topologies-state {
      config "false";
      description
        "This container acts as the top-level state data element of
         operational data.";
      list topology {
        key "te-topology-id";
        description
          "This is the model of an abstract topology. A topology



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          contains nodes and links. Each topology MUST be identified
          by a unique te-topology-id for reason that a network could
          contain many topologies.";
        leaf te-topology-id {
          type te-topology-id;
          description
            "It is presumed that a datastore will contain many
            topologies. To distinguish between topologies it is
            vital to have UNIQUE topology identifiers.";
        }
        leaf server-provided {
          type boolean;
          config false;
          description
            "Indicates whether the topology is configurable by
               clients, or whether it is provided by the server. This
              leaf is populated by the server implementing the model.
            It is set to false for topologies that are created by a
            client; it is set to true otherwise.  If it is set to
              true, any attempt to edit the topology MUST be rejected.";
        }
        container topology-types {
          description
            "This container is used to identify the type, or types (as
            a topology can support several types simultaneously), of
            the topology.
            Topology types are the subject of several integrity
            constraints that an implementing server can validate in
            order to maintain integrity of the datastore.
            Topology types are indicated through separate data nodes;
            the set of topology types is expected to increase over
            time.
            To add support for a new topology, an augmenting module
            needs to augment this container with a new empty optional
            container to indicate the new topology type.
            The use of a container allows to indicate a
            subcategorization of topology types.
            The container SHALL NOT be augmented with any data nodes
            that serve a purpose other than identifying a particular
            topology type.";
          uses te-topology-type; // Defines the TE topology type.
        }
        list node {
          key "te-node-id";
          leaf te-node-id {
            type te-node-id;
            description
              "The identifier of a node in the topology.



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              A node is specific to a topology to which it belongs.";
          }
          description
            "The list of network nodes defined for the topology.";
          leaf te-node-template {
            type leafref {
              path "/te-topologies/node-template/name";
            }
            description
              "The reference to a TE node template.";
          }
          uses te-node-attributes;
          uses te-node-state-attributes;
        }
        list link {
          key "source-te-node-id source-te-link-id "
            + "dest-te-node-id dest-te-link-id";
          leaf source-te-node-id {
            type leafref {
              path "../../node/te-node-id";
            }
            mandatory true;
            description
              "Source node identifier, must be in same topology.";
          }
          leaf source-te-link-id {
            type leafref {
              path "../../node[te-node-id = "
                + "current()/../source-te-node-id]/"
                + "te-node-attributes/te-link/te-link-id";
            }
            mandatory true;
            description
              "Source TE link identifier, must be in same topology.";
          }
          leaf dest-te-node-id {
            type leafref {
              path "../../node/te-node-id";
            }
            mandatory true;
            description
              "Destination node identifier, must be in the same
              topology.";
          }
          leaf dest-te-link-id {
            type leafref {
              path "../../node[te-node-id = "
                + "current()/../dest-te-node-id]/"



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                + "te-node-attributes/te-link/te-link-id";
            }
            mandatory true;
            description
              "Destination TE link identifier, must be in same
              topology.";
          }
          description
            "TE link is a logical construct that represents a way
            to group/map information about certain physical
            resources (and their properties) that interconnect TE
            nodes.
            A Network Link connects a by Local (Source) node and
            a Remote (Destination) Network Nodes via a set of the
            nodes' TE links.
            As it is possible to have several links between the
            same source and destination nodes, and as a link
            could potentially be re-homed, to ensure that we
            would always know to distinguish between
            links, every link is identified by a dedicated link
            identifier.
            Note that a link models a point-to-point link, not a
            multipoint link.";
          leaf te-link-template {
            type leafref {
              path "/te-topologies/link-template/name";
            }
            description
              "The reference to a TE link template.";
          }
          uses te-link-attributes;
          uses te-link-state-attributes;
        } // link
      } // topology
    } // te-topologies

    augment "/te-topologies-state/topology/link/te-link-attributes/"
      + "underlay" {
      description "Add state attributes to te-link underlay.";
      uses te-link-state-underlay-attributes;
    }

    /*
     * Notifications
     */

    notification te-node-event {
      description "Notification event for TE node";



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      leaf event-type {
        type te-topology-event-type;
        description "Event type";
      }
      uses node-ref;
      uses te-topology-type;
      uses tet:te-node-attributes;
    }

    notification te-link-event {
      description "Notification event for TE link";
      leaf event-type {
        type te-topology-event-type;
        description "Event type";
      }
      uses link-ref;
      uses te-topology-type;
      uses tet:te-link-attributes;
    }

    augment "/te-link-event/te-link-attributes/underlay" {
      description "Add state attributes to te-link underlay.";
      uses te-link-state-underlay-attributes;
    }
  }
  <CODE ENDS>

4.  Normative References

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

   [RFC6020]  Bjorklund, M., "YANG - A Data Modeling Language for the
              Network Configuration Protocol (NETCONF)", RFC 6020,
              October 2010.

   [RFC6241]  Enns, R., Bjorklund, M., Schoenwaelder, J., and A.
              Bierman, "Network Configuration Protocol (NETCONF)", RFC
              6241, June 2011.

Authors' Addresses

   Xufeng Liu
   Ericsson

   Email: xufeng.liu@ericsson.com





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   Igor Bryskin
   ADVA Optical Networking

   Email: ibryskin@advaoptical.com


   Vishnu Pavan Beeram
   Juniper Networks

   Email: vbeeram@juniper.net


   Tarek Saad
   Cisco Systems Inc.

   Email: tsaad@cisco.com


   Himanshu Shah
   Ciena

   Email: tsaad@cisco.com





























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