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YANG Data Model for TE Topologies
draft-ietf-teas-yang-te-topo-02

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This is an older version of an Internet-Draft that was ultimately published as RFC 8795.
Authors Xufeng Liu , Igor Bryskin , Vishnu Pavan Beeram , Tarek Saad , Himanshu C. Shah , Oscar Gonzalez de Dios
Last updated 2015-10-19
Replaces draft-liu-teas-yang-te-topo
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draft-ietf-teas-yang-te-topo-02
TEAS Working Group                                           Xufeng Liu 
Internet Draft                                                 Ericsson 
Intended status: Standards Track                           Igor Bryskin 
                                                ADVA Optical Networking 
                                                    Vishnu Pavan Beeram 
                                                       Juniper Networks 
                                                             Tarek Saad 
                                                      Cisco Systems Inc 
                                                          Himanshu Shah 
                                                                  Ciena 
                                                 Oscar Gonzalez De Dios 
                                                             Telefonica 
                                                                                
Expires: April 19, 2016                                October 19, 2015 
                                    
 
                     YANG Data Model for TE Topologies 
                      draft-ietf-teas-yang-te-topo-02 

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   This Internet-Draft will expire on April 19, 2016. 
    
Copyright Notice 

   Copyright (c) 2015 IETF Trust and the persons identified as the 
   document authors. All rights reserved.  

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

   This document defines a YANG data model for representing, retrieving 
   and manipulating TE Topologies. The model serves as a base model 
   that other technology specific TE Topology models can augment. 

Conventions used in this document 

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

Table of Contents 

   1. Introduction...................................................3 
      1.1. Terminology...............................................3 
      1.2. Tree Structure - Legend...................................4 
      1.3. Prefixes in Data Node Names...............................5 
   2. Characterizing TE Topologies...................................5 
   3. Model Applicability............................................6 
      3.1. Native TE Topologies......................................6 
      3.2. Customized TE Topologies..................................8 
   4. Modeling Considerations.......................................10 
      4.1. Generic network topology building blocks.................10 
      4.2. Technology agnostic TE Topology model....................11 
      4.3. Model Structure..........................................11 
      4.4. Topology Identifiers.....................................12 
      4.5. Generic TE Link Attributes...............................13 
      4.6. Generic TE Node Attributes...............................13 
      4.7. TED Information Sources..................................14 
      4.8. Overlay/Underlay Relationship............................14 
      4.9. Scheduling Parameters....................................16 
      4.10. Templates...............................................16 
      4.11. Notifications...........................................17 
      4.12. Open Items..............................................18 
 
 
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   5. Tree Structure................................................18 
   6. TE Topology Yang Module.......................................43 
   7. Security Considerations.......................................79 
   8. IANA Considerations...........................................79 
   9. References....................................................79 
      9.1. Normative References.....................................79 
      9.2. Informative References...................................80 
   10. Acknowledgments..............................................80 
   Appendix A - Schedule Model......................................80 
      A.1 Tree Structure............................................80 
      A.2 YANG Module...............................................81 
   Contributors.....................................................82 
   Authors' Addresses...............................................82 
    
1. Introduction 

   The Traffic Engineering Database (TED) is an essential component of 
   Traffic Engineered (TE) systems that are based on MPLS-TE [RFC2702] 
   and GMPLS [RFC3945]. The TED is a collection of all TE information 
   about all TE nodes and TE links in the network. The TE Topology is a 
   schematic arrangement of TE nodes and TE links present in a given 
   TED. There could be one or more TE Topologies present in a given 
   Traffic Engineered system. The TE Topology is the topology on which 
   path computational algorithms are run to compute Traffic Engineered 
   Paths (TE Paths). 

   This document defines a YANG [RFC6020] 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. Terminology 

   TED: The Traffic Engineering Database is a collection of all TE 
   information about all TE nodes and TE links in a given network. 

   TE-Topology: The TE Topology is a schematic arrangement of TE nodes 
   and TE links in a given TED. It forms the basis for a graph suitable 
   for TE path computations. 

   Native TE Topology: Native TE Topology is a topology that is native 
   to a given provider network. This is the topology on which path 
   computational algorithms are run to compute TE Paths. 

   Customized TE Topology: Customized TE Topology is a custom topology 
   that is produced by a provider for a given Client. This topology 
 
 
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   typically augments the Client's Native TE Topology. Path 
   computational algorithms aren't typically run on the Customized TE 
   Topology; they are run on the Client's augmented Native TE Topology.   

1.2. Tree Structure - Legend 

   A simplified graphical representation of the data model is presented 
   in Section 5 of this document. The following notations are used for 
   the YANG model data tree representation. 
    
      <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. 
    

 
 
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1.3. 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 
    
2. Characterizing TE Topologies 

   The data model proposed by this document takes the following 
   characteristics of TE Topologies into account: 

   - TE Topology is an abstract control-plane representation of the 
     data-plane topology. Hence attributes specific to the data-plane 
     must make their way into the corresponding TE Topology modeling. 
     The TE Topology comprises of dynamic auto-discovered data (data 
     that may change frequently - example: unreserved bandwidth 
     available on data-plane links) as well as fairly static data (data 
     that rarely changes- examples: layer network identification, 
     switching and adaptation capabilities and limitations, fate 
     sharing, administrative colors) associated with data-plane nodes 
     and links. It is possible for a single TE Topology to encompass TE 
     information at multiple switching layers. 
      
   - TE Topologies are protocol independent. Information about 
     topological elements may be learnt via link-state protocols, but 
     the topology can exist without being dependent on any particular 
     protocol. 
      
   - TE Topology may not be congruent to the routing topology (topology 
     constructed based on routing adjacencies) in a given TE System. 
     There isn't always a one-to-one association between a TE-link and 
     a routing adjacency. For example, the presence of a TE link 
     between a pair of nodes doesn't necessarily imply the existence of 
     a routing-adjacency between these nodes. 
      

 
 
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   - Each TE Topological element has an information source associated 
     with it. In some scenarios, there could be more than one 
     information source associated with each topological element. 
      
   - TE Topologies can be hierarchical. Each node and link of a given 
     TE Topology can be associated with respective underlay topology. 
     This means that each node and link of a given TE Topology can be 
     associated with an independent stack of supporting TE Topologies. 
      
   - TE Topologies can be customized. TE topologies of a given network 
     presented by the network provider to its client could be 
     customized on per-client request basis. This customization could 
     be performed by provider, by client or by provider/client 
     negotiation. The relationship between a customized topology (as 
     presented to the client) and provider's native topology (as known 
     in its entirety to the provider itself) could be captured as 
     hierarchical (overlay-underlay), but otherwise the two topologies 
     are decoupled from each other. 
      
3. Model Applicability 

3.1. Native TE Topologies 

   The model discussed in this draft can be used to represent and 
   retrieve native TE topologies on a given TE system.  

                                          
     +---+       +---+        +---+         +---+         +---+ 
     | R1|-------| R2|--------| R3|---------| R4|---------| R5|  
     +---+       +---+        +---+         +---+         +---+  
       |                      /   \         /   \         / 
       |                     /     \       /     \       / 
       |                    /       \     /       \     / 
       |                   /         \   /         \   / 
       |                  /           \ /           \ / 
     +---+             +---+         +---+         +---+ 
     | R6|-------------| R7|         | R8|---------| R9| 
     +---+             +---+         +---+         +---+  
    
                    Figure 1a: Example Network Topology 
                                      
   Consider the network topology depicted in Figure 1a (R1 .. R9 are 
   nodes representing routers). An implementation MAY choose to 
   construct a native TE Topology using all nodes and links present in 
   the given TED as depicted in Figure 1b. The data model proposed in 
   this document can be used to retrieve/represent this TE topology. 
 
 
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          --------------- 
          | Native      |                   |  [ ] TE Node  
          | TE-Topology |                   |  +++ TE Link  
          ---------------                   o--------------
   __________________     
            [R1] ++++ [R2] ++++ [R3] ++++ [R4] ++++ [R5] 
              +                +    +    +    +    + 
              +               +      +  +      +  + 
              +              +        ++        ++ 
            [R6] +++++++++ [R7]      [R8] ++++ [R9] 
          
                Figure 1b: Native TE Topology as seen on Node R3 
          
   Consider the case of the topology being split in a way that some 
   nodes participate in OSPF-TE while others participate in ISIS-TE 
   (Figure 2a). An implementation MAY choose to construct separate TE 
   Topologies based on the information source. The native TE Topologies 
   constructed using only nodes and links that were learnt via a 
   specific information source are depicted in Figure 2b. The data 
   model proposed in this document can be used to retrieve/represent 
   these TE topologies. 

   Similarly, the data model can be used to represent/retrieve a TE 
   Topology that is constructed using only nodes and links that belong 
   to a particular technology layer. The data model is flexible enough 
   to retrieve and represent many such native TE Topologies. 

                                     : 
   TE info distributed via ISIS-TE   :  TE info distributed via OSPF-TE 
                                     : 
          +---+       +---+        +---+         +---+         +---+ 
          | R1|-------| R2|--------| R3|---------| R4|---------| R5|  
          +---+       +---+        +---+         +---+         +---+  
            |                      / : \         /   \         / 
            |                     /  :  \       /     \       / 
            |                    /   :   \     /       \     / 
            |                   /    :    \   /         \   / 
            |                  /     :     \ /           \ / 
          +---+             +---+    :    +---+         +---+ 
          | R6|-------------| R7|    :    | R8|---------| R9| 
          +---+             +---+    :    +---+         +---+  
                                     : 
         

                    Figure 2a: Example Network Topology 
                                      
 
 
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           -----------------------   :  ----------------------- 
           |Native TE Topology   |   :  |Native TE Topology   | 
           |Info-Source: ISIS-TE |   :  |Info-Source: OSPF-TE | 
           -----------------------   :  ----------------------- 
                                     : 
            [R1] ++++ [R2] ++++ [R3] : [R3'] ++++ [R4] ++++ [R5] 
             +                +      :      +    +    +    + 
             +               +       :       +  +      +  + 
             +              +        :        ++        ++ 
            [R6] +++++++++ [R7]      :       [R8] ++++ [R9] 
         

               Figure 2b: Native TE Topologies as seen on Node R3 
         

3.2. Customized TE Topologies 

   The model discussed in this draft can be used to represent, retrieve 
   and manipulate customized TE Topologies. The model allows the 
   provider to present the network in abstract TE Terms on a per client 
   basis. These customized topologies contain sufficient information 
   for the path computing client to select paths according to its 
   policies.  

                                  | +---+            /-\  
                                  | |   | Router    (   ) WDM   
                                  | +---+ Node       \-/  node  
                                  | 
                                  o----------------------------_____ 
   __                                        
     +---+        /-\          /-\           /-\          +---+  
     | R1|-------( A )--------( C )---------( E )---------| R3|  
     +---+        \-/          \-/           \-/          +---+  
                              /   \         /   \  
                             /     \       /     \  
                            /       \     /       \  
                           /         \   /         \  
                          /           \ /           \  
         +---+          /-\           /-\           /-\          +---+  
         | R2|---------( B )---------( D )---------( F )---------| R4|  
         +---+          \-/           \-/           \-/          +---+ 
    
                 Figure 3: Example packet optical topology  
    

 
 
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   Consider the network topology depicted in Figure 3. This is a 
   typical packet optical transport deployment scenario where the WDM 
   layer network domain serves as a Server Network Domain providing 
   transport connectivity to the packet layer network Domain (Client 
   Network Domain). Nodes R1, R2, R3 and R4 are IP routers that are 
   connected to an Optical WDM transport network. A, B, C, D, E and F 
   are WDM nodes that constitute the Server Network Domain. 
    
                                            | *****  B-F WDM Path                
                                            | @@@@@  B-E WDM Path 
                                            | $$$$$  A-E WDM Path   
                                            o--------------------_  
                                          
     +---+        /-\ $$$$$$$$ /-\ $$$$$$$$$ /-\          +---+  
     | R1|-------( A )--------( C )---------( E )---------| R3|  
     +---+        \-/         @\-/ @@@@@@@@@ \-/          +---+  
                             @/   \         /   \  
                            @/     \       /     \  
                           @/       \     /       \  
                          @/         \   /         \  
                         @/           \ /           \  
         +---+          /-\ ********* /-\ ********* /-\          +---+  
         | R2|---------( B )---------( D )---------( F )---------| R4|  
         +---+          \-/           \-/           \-/          +---+ 
    
                Figure 4a: Paths within the provider domain 
    
    
    
                 ++++++++ [A] ++++++++++++++++++++ [E] +++++++++  
                                              +++++   
                                          ++++          
                                      ++++     
                                  ++++       
                              ++++            
                 ++++++++ [B] ++++++++++++++++++++ [F] +++++++++  
    
         Figure 4b: Customized TE Topology provided to the Client 
                                              
   The goal here is to augment the Client TE Topology with a customized 
   TE Topology provided by the WDM network. Given the availability of 
   the paths A-E, B-F and B-E (Figure 4a), a customized TE Topology as 
   depicted in Figure 4b is provided to the Client. This customized TE 
   Topology is merged with the Client's Native TE Topology and the 
   resulting topology is depicted in Figure 4c.  

 
 
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            [R1] ++++++++ [A] ++++++++++++++++++++ [E] +++++++++ [R3]  
                                              +++++   
                                          ++++          
                                      ++++     
                                  ++++       
                              ++++            
            [R2] ++++++++ [B] ++++++++++++++++++++ [F] +++++++++ [R4]   
                  
   Figure 4c: Customized TE Topology merged with the Client's Native TE 
                                 Topology 
 

   The data model proposed in this document can be used to 
   retrieve/represent/manipulate the customized TE Topology depicted in 
   Figure 4b. 
                                      
4. Modeling Considerations 

4.1. Generic network topology building blocks 

   The generic network topology building blocks are discussed in [YANG-
   NET-TOPO]. The TE Topology model proposed in this document augments 
   and uses the ietf-network-topology module defined in [YANG-NET-
   TOPO].  

                  +------------------------+ 
                  |       Generic          | 
                  | Network Topology Model | 
                  | (ietf-network-topology)| 
                  +------------------------+ 
                               | 
                               | 
                               | 
                               V 
                  +------------------------+                                    
                  |       TE Topology      | 
                  |         Model          | 
                  |                        | 
                  +------------------------+ 
    
          Figure 5: Augmenting the Generic Network Topology Model 
    

 
 
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4.2. Technology agnostic TE Topology 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. 

                     +-------------------+ 
                     |     Generic       | 
                     | TE Topology Model | 
                     +-------------------+ 
                               | 
            +-------------+-------------+-------------+ 
            |             |             |             | 
            V             V             V             V 
      +------------+                            +------------+ 
      | Technology |                            | Technology | 
      |  Specific  |   ......................   |  Specific  | 
      | TE Topology|                            | TE Topology| 
      |   Model 1  |                            |   Model n  | 
      +------------+                            +------------+ 
    
      Figure 6: Augmenting the Technology agnostic TE Topology model 
    
4.3. Model Structure 

   The high-level model structure proposed by this document is as shown 
   below: 

   module: ietf-te-topology 
   augment /nw:network/nw:network-types: 
      +--rw te-topology! 
   augment /nw:network: 
      +--rw te! 
         +--rw provider-id       te-global-id 
         +--rw client-id         te-global-id 
         +--rw te-topology-id    te-topology-id 
         +--rw config 
         |  ............ 
         +--ro state 
         |  ............ 
         +--rw templates 
            +--rw node-template* [name] {template}? 
            |  ............ 
            +--rw link-template* [name] {template}? 
               ............ 
 
 
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   augment /nw:network/nw:node: 
      +--rw te! 
         +--rw te-node-id    te-node-id 
         +--rw config 
         |  ............ 
         +--ro state 
            ............ 
    
   augment /nw:network/nt:link: 
      +--rw te! 
         +--rw config 
         |  .......... 
         +--ro state 
            .......... 
    
   augment /nw:network/nw:node/nt:termination-point: 
      +--rw te! 
         +--rw te-tp-id    te-tp-id 
         +--rw config 
         |  ............ 
         +--ro state 
            ............ 
    
   notifications: 
      +---n te-node-event 
      |  ............ 
      +---n te-link-event 
         ............ 
       
4.4. Topology Identifiers 

   The TE-Topology is uniquely identified by a key that has 3 
   constituents - te-topology-id, provider-id and client-id. The 
   combination of provider-id and te-topology-id uniquely identifies a 
   native TE Topology on a given provider. The client-id is used only 
   when Customized TE Topologies come into play; a value of "0" is used 
   as the client-id for native TE Topologies. 

   augment /nw:network: 
      +--rw te! 
         +--rw provider-id       te-global-id 
         +--rw client-id         te-global-id 
         +--rw te-topology-id    te-topology-id 
    

 
 
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4.5. Generic TE Link Attributes 

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

     +--rw te-link-attributes 
        ..................... 
        +--rw admin-status?                     te-admin-status 
        +--rw performance-metric-throttle {te-performance-metric}? 
        |  ..................... 
        +--rw link-index?                       uint64 
        +--rw administrative-group?             te-types:admin-groups 
        +--rw max-link-bandwidth?               decimal64 
        +--rw max-resv-link-bandwidth?          decimal64 
        +--rw unreserved-bandwidth* [priority] 
        |  ..................... 
        +--rw te-default-metric?                uint32 
        +--rw performance-metric {te-performance-metric}? 
        |  ..................... 
        +--rw link-protection-type?             enumeration 
        +--rw interface-switching-capability* [switching-capability] 
        |  ..................... 
        +--rw te-srlgs 
           ..................... 
      
    
4.6. Generic TE Node Attributes 

   The model covers the definitions for generic TE Node attributes. The 
   definition of a generic connectivity matrix is shown below: 

     +--rw te-node-attributes 
        ........... 
        +--rw connectivity-matrix* [id] 
        |  +--rw id            uint32 
        |  +--rw from 
        |  |  +--rw tp-ref?        leafref 
        |  |  +--rw node-ref?      leafref 
        |  |  +--rw network-ref?   leafref 
        |  +--rw to 
        |  |  +--rw tp-ref?        leafref 
        |  |  +--rw node-ref?      leafref 
        |  |  +--rw network-ref?   leafref 
        |  +--rw is-allowed?   boolean 
    
 
 
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4.7. TED Information Sources 

   The model allows each TE topological element to have multiple TE 
   information sources (OSPF-TE, ISIS-TE, BGP-LS, User-Configured, 
   System-Processed, Other). Each information source is associated with 
   a credibility preference to indicate precedence. In scenarios where 
   a customized TE Topology is merged into a Client's native TE 
   Topology, the merged topological elements would point to the 
   corresponding customized TE Topology as its information source. 

   augment /nw:network/nw:node: 
      +--rw te! 
         ........... 
         +--ro state 
            ........ 
            +--ro information-source-state 
               +--ro credibility-preference?   uint16 
               +--ro topology 
               |  +--ro provider-id-ref?      leafref 
               |  +--ro client-id-ref?        leafref 
               |  +--ro te-topology-id-ref?   leafref 
               |  +--ro network-id-ref?       leafref 
               +--ro routing-instance?         string 
    
   augment /nw:network/nt:link: 
      +--rw te! 
         ........... 
         +--ro state 
            ......... 
            +--ro information-source?         enumeration 
            +--ro information-source-state 
            |  +--ro credibility-preference?   uint16 
            |  +--ro topology 
            |  |  +--ro provider-id-ref?      leafref 
            |  |  +--ro client-id-ref?        leafref 
            |  |  +--ro te-topology-id-ref?   leafref 
            |  |  +--ro network-id-ref?       leafref 
            |  +--ro routing-instance?         string 
            +--ro alt-information-sources* [information-source] 
            |  ............ 
           

4.8. Overlay/Underlay Relationship 

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

   This relationship is captured via the "underlay-topology" field for 
   the node and via the "underlay" field for the link. The use of these 
   fields is optional and this functionality is tagged as a "feature" 
   ("te-topology-hierarchy"). 

   augment /nw:network/nw:node: 
      +--rw te! 
         +--rw te-node-id    te-node-id 
         +--rw config 
         |  +--rw te-node-template*     leafref {template}? 
         |  +--rw te-node-attributes 
         |     .................... 
         |     +--rw underlay-topology {te-topology-hierarchy}? 
         |        +--rw provider-id-ref?      leafref 
         |        +--rw client-id-ref?        leafref 
         |        +--rw te-topology-id-ref?   leafref 
         |        +--rw network-id-ref?       leafref 
    
   augment /nw:network/nt:link: 
      +--rw te! 
         +--rw config 
         |  ......... 
         |  +--rw te-link-attributes 
         |     .................... 
         |     +--rw underlay! {te-topology-hierarchy}? 
         |     |  +--rw underlay-primary-path 
         |     |  |  +--rw provider-id-ref?      leafref 
         |     |  |  +--rw client-id-ref?        leafref 
         |     |  |  +--rw te-topology-id-ref?   leafref 
         |     |  |  +--rw network-id-ref?       leafref 
         |     |  |  +--rw path-element* [path-element-id] 
         |     |  |     ............... 
         |     |  +--rw underlay-backup-path* [index] 
         |     |  |  +--rw index                 uint32 
         |     |  |  +--rw provider-id-ref?      leafref 
         |     |  |  +--rw client-id-ref?        leafref 
         |     |  |  +--rw te-topology-id-ref?   leafref 
         |     |  |  +--rw network-id-ref?       leafref 
         |     |  |  +--rw path-element* [path-element-id] 
         |     |  |     ............... 
         |     |  +--rw underlay-protection-type?   uint16 
 
 
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         |     |  +--rw underlay-trail-src 
         |     |  |  ........... 
         |     |  |  +--rw network-ref?   leafref 
         |     |  +--rw underlay-trail-des 
         |     |     ........... 
    

4.9. Scheduling Parameters 

   The model allows time scheduling parameters to be specified for each 
   topological element or for the topology as a whole. These parameters 
   allow the provider to present different topological views to the 
   client at different time slots. The use of "scheduling parameters" 
   is optional and this functionality is tagged as a "feature" 
   ("configuration-schedule"). [Editor's Note: The notion of 
   "scheduling parameters" has wider applicability. The "schedules" 
   module (which is imported by the TE Topology module) is discussed 
   separately in Appendix A. The expectation is that this will 
   eventually be discussed in a separate document.] 

4.10. Templates 

   The data model provides the users with the ability to define 
   templates and apply them to link and node configurations. The use of 
   "template" configuration is optional and this functionality is 
   tagged as a "feature" ("template").  

     +--rw topology* [provider-id client-id te-topology-id] 
     |  ........... 
     |  +--rw node* [te-node-id] 
     |  |  +--rw te-node-template?     leafref {template}?  
     |  |     .......... 
     |  +--rw link* [source-te-node-id source-te-link-id dest-te-node-
   id dest-te-link-id] 
     |     +--rw te-link-template?     leafref {template}? 
     |        .......... 
     | 
     +--rw node-template* [name] {template}? 
     |  +--rw name                       te-template-name 
     |  +--rw priority?                  uint16 
     |  +--rw reference-change-policy?   enumeration 
     |  +--rw te-node-template*          leafref 
     |  +--rw te-node-attributes 
     |     .......... 
     +--rw link-template* [name] {template}? 
        +--rw name                       te-template-name 
 
 
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        +--rw priority?                  uint16 
        +--rw reference-change-policy?   enumeration 
        +--rw te-link-template*          leafref 
        +--rw te-link-attributes 
           .......... 
    
   A template can be constructed using multiple other templates. When 
   two or more templates specify values for the same configuration 
   field, the value from the template with the highest priority is 
   used. The reference-change-policy specifies the action that needs to 
   be taken when the template changes on a configuration node that has 
   a reference to this template. The choices of action include taking 
   no action, rejecting the change to the template and applying the 
   change to the corresponding configuration. [Editor's Note: The 
   notion of "templates" has wider applicability. It is possible for 
   this to be discussed in a separate document.] 
    
4.11. Notifications 

   Notifications are a key component of any topology data model.  

   [YANG-PUSH] defines a subscription and push mechanism for YANG 
   datastores. This mechanism currently allows the user to: 

   - Subscribe notifications on a per client basis 
   - Specify subtree filters or xpath filters so that only interested 
     contents will be sent. 
   - Specify either periodic or on-demand notifications. 

   The authors would like to recommend the use of this mechanism for 
   the TE-Topology notifications. They would also like to suggest the 
   following extensions to [YANG-PUSH] 

   - Specify specific entities that will trigger the push 
     notifications. These entities can be specified by xpath, like the 
     way a filter is specified. 
      
   - Specify or limit the triggering event type, e.g. "add", "delete", 
     "modify", or "all". The system sends the push notifications only 
     when such events happen on the triggering entities. 
      
   - Have an option to request either "incremental" or "full" 
     notifications for an entity. For "incremental", the notification 
     will contain only the changed attributes. 

    
 
 
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4.12. Open Items 

   - Coordinating changes to [YANG-PUSH]: The changes to [YANG-PUSH] 
     discussed in Section 4.10 will need to be coordinated with the 
     authors of that draft. 

5. Tree Structure 

   module: ietf-te-topology 
   augment /nw:network/nw:network-types: 
      +--rw te-topology! 
   augment /nw:network: 
      +--rw te! 
         +--rw provider-id       te-global-id 
         +--rw client-id         te-global-id 
         +--rw te-topology-id    te-topology-id 
         +--rw config 
         |  +--rw schedules 
         |     +--rw schedule* [schedule-id] 
         |        +--rw schedule-id          uint32 
         |        +--rw start?               yang:date-and-time 
         |        +--rw schedule-duration?   string 
         |        +--rw repeat-interval?     string 
         +--ro state 
         |  +--ro schedules 
         |     +--ro schedule* [schedule-id] 
         |        +--ro schedule-id          uint32 
         |        +--ro start?               yang:date-and-time 
         |        +--ro schedule-duration?   string 
         |        +--ro repeat-interval?     string 
         +--rw templates 
            +--rw node-template* [name] {template}? 
            |  +--rw name                       te-template-name 
            |  +--rw priority?                  uint16 
            |  +--rw reference-change-policy?   enumeration 
            |  +--rw te-node-attributes 
            |     +--rw schedules 
            |     |  +--rw schedule* [schedule-id] 
            |     |     +--rw schedule-id          uint32 
            |     |     +--rw start?               yang:date-and-time 
            |     |     +--rw schedule-duration?   string 
            |     |     +--rw repeat-interval?     string 
            |     +--rw admin-status?          te-admin-status 
            |     +--rw connectivity-matrix* [id] 
            |     |  +--rw id            uint32 
            |     |  +--rw from 
 
 
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            |     |  |  +--rw tp-ref?        leafref 
            |     |  |  +--rw node-ref?      leafref 
            |     |  |  +--rw network-ref?   leafref 
            |     |  +--rw to 
            |     |  |  +--rw tp-ref?        leafref 
            |     |  |  +--rw node-ref?      leafref 
            |     |  |  +--rw network-ref?   leafref 
            |     |  +--rw is-allowed?   boolean 
            |     +--rw domain-id?             uint32 
            |     +--rw flag*                  te-node-flag 
            |     +--rw is-abstract?           empty 
            |     +--rw name?                  inet:domain-name 
            |     +--rw signaling-address*     inet:ip-address 
            |     +--rw underlay-topology {te-topology-hierarchy}? 
            |        +--rw provider-id-ref?      leafref 
            |        +--rw client-id-ref?        leafref 
            |        +--rw te-topology-id-ref?   leafref 
            |        +--rw network-id-ref?       leafref 
            +--rw link-template* [name] {template}? 
               +--rw name                       te-template-name 
               +--rw priority?                  uint16 
               +--rw reference-change-policy?   enumeration 
               +--rw te-link-attributes 
                  +--rw schedules 
                  |  +--rw schedule* [schedule-id] 
                  |     +--rw schedule-id          uint32 
                  |     +--rw start?               yang:date-and-time 
                  |     +--rw schedule-duration?   string 
                  |     +--rw repeat-interval?     string 
                  +--rw access-type?                      te-link-
   access-type 
                  +--rw flag*                             te-link-flag 
                  +--rw is-abstract?                      empty 
                  +--rw name?                             string 
                  +--rw underlay! {te-topology-hierarchy}? 
                  |  +--rw underlay-primary-path 
                  |  |  +--rw provider-id-ref?      leafref 
                  |  |  +--rw client-id-ref?        leafref 
                  |  |  +--rw te-topology-id-ref?   leafref 
                  |  |  +--rw network-id-ref?       leafref 
                  |  |  +--rw path-element* [path-element-id] 
                  |  |     +--rw path-element-id     uint32 
                  |  |     +--rw (type)? 
                  |  |        +--:(ipv4-address) 
                  |  |        |  +--rw v4-address?         inet:ipv4-
   address 
 
 
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                  |  |        |  +--rw v4-prefix-length?   uint8 
                  |  |        |  +--rw v4-loose?           boolean 
                  |  |        +--:(ipv6-address) 
                  |  |        |  +--rw v6-address?         inet:ipv6-
   address 
                  |  |        |  +--rw v6-prefix-length?   uint8 
                  |  |        |  +--rw v6-loose?           boolean 
                  |  |        +--:(as-number) 
                  |  |        |  +--rw as-number?          uint16 
                  |  |        +--:(unnumbered-link) 
                  |  |        |  +--rw router-id?          inet:ip-
   address 
                  |  |        |  +--rw interface-id?       uint32 
                  |  |        +--:(label) 
                  |  |           +--rw value?              uint32 
                  |  +--rw underlay-backup-path* [index] 
                  |  |  +--rw index                 uint32 
                  |  |  +--rw provider-id-ref?      leafref 
                  |  |  +--rw client-id-ref?        leafref 
                  |  |  +--rw te-topology-id-ref?   leafref 
                  |  |  +--rw network-id-ref?       leafref 
                  |  |  +--rw path-element* [path-element-id] 
                  |  |     +--rw path-element-id     uint32 
                  |  |     +--rw (type)? 
                  |  |        +--:(ipv4-address) 
                  |  |        |  +--rw v4-address?         inet:ipv4-
   address 
                  |  |        |  +--rw v4-prefix-length?   uint8 
                  |  |        |  +--rw v4-loose?           boolean 
                  |  |        +--:(ipv6-address) 
                  |  |        |  +--rw v6-address?         inet:ipv6-
   address 
                  |  |        |  +--rw v6-prefix-length?   uint8 
                  |  |        |  +--rw v6-loose?           boolean 
                  |  |        +--:(as-number) 
                  |  |        |  +--rw as-number?          uint16 
                  |  |        +--:(unnumbered-link) 
                  |  |        |  +--rw router-id?          inet:ip-
   address 
                  |  |        |  +--rw interface-id?       uint32 
                  |  |        +--:(label) 
                  |  |           +--rw value?              uint32 
                  |  +--rw underlay-protection-type?   uint16 
                  |  +--rw underlay-trail-src 
                  |  |  +--rw tp-ref?        leafref 
                  |  |  +--rw node-ref?      leafref 
 
 
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                  |  |  +--rw network-ref?   leafref 
                  |  +--rw underlay-trail-des 
                  |     +--rw tp-ref?        leafref 
                  |     +--rw node-ref?      leafref 
                  |     +--rw network-ref?   leafref 
                  +--rw admin-status?                     te-admin-
   status 
                  +--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 
                  |  |  +--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-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 link-index?                       uint64 
                  +--rw administrative-group?             te-
   types:admin-groups 
                  +--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 
 
 
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                  |  |  +--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-capability* [switching-
   capability] 
                  |  +--rw switching-capability               
   identityref 
                  |  +--rw encoding?                          
   identityref 
                  |  +--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 interface-adjustment-capability* [upper-sc] 
                  |     +--rw upper-sc             identityref 
                  |     +--rw upper-encoding?      identityref 
                  |     +--rw max-lsp-bandwidth* [priority] 
                  |        +--rw priority     uint8 
                  |        +--rw bandwidth?   decimal64 
                  +--rw te-srlgs 
                     +--rw values*   te-types:srlg 
   augment /nw:network/nw:node: 
 
 
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      +--rw te! 
         +--rw te-node-id    te-node-id 
         +--rw config 
         |  +--rw te-node-template*     leafref {template}? 
         |  +--rw te-node-attributes 
         |     +--rw schedules 
         |     |  +--rw schedule* [schedule-id] 
         |     |     +--rw schedule-id          uint32 
         |     |     +--rw start?               yang:date-and-time 
         |     |     +--rw schedule-duration?   string 
         |     |     +--rw repeat-interval?     string 
         |     +--rw admin-status?          te-admin-status 
         |     +--rw connectivity-matrix* [id] 
         |     |  +--rw id            uint32 
         |     |  +--rw from 
         |     |  |  +--rw tp-ref?        leafref 
         |     |  |  +--rw node-ref?      leafref 
         |     |  |  +--rw network-ref?   leafref 
         |     |  +--rw to 
         |     |  |  +--rw tp-ref?        leafref 
         |     |  |  +--rw node-ref?      leafref 
         |     |  |  +--rw network-ref?   leafref 
         |     |  +--rw is-allowed?   boolean 
         |     +--rw domain-id?             uint32 
         |     +--rw flag*                  te-node-flag 
         |     +--rw is-abstract?           empty 
         |     +--rw name?                  inet:domain-name 
         |     +--rw signaling-address*     inet:ip-address 
         |     +--rw underlay-topology {te-topology-hierarchy}? 
         |        +--rw provider-id-ref?      leafref 
         |        +--rw client-id-ref?        leafref 
         |        +--rw te-topology-id-ref?   leafref 
         |        +--rw network-id-ref?       leafref 
         +--ro state 
            +--ro te-node-template*           leafref {template}? 
            +--ro te-node-attributes 
            |  +--ro schedules 
            |  |  +--ro schedule* [schedule-id] 
            |  |     +--ro schedule-id          uint32 
            |  |     +--ro start?               yang:date-and-time 
            |  |     +--ro schedule-duration?   string 
            |  |     +--ro repeat-interval?     string 
            |  +--ro admin-status?          te-admin-status 
            |  +--ro connectivity-matrix* [id] 
            |  |  +--ro id            uint32 
            |  |  +--ro from 
 
 
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            |  |  |  +--ro tp-ref?        leafref 
            |  |  |  +--ro node-ref?      leafref 
            |  |  |  +--ro network-ref?   leafref 
            |  |  +--ro to 
            |  |  |  +--ro tp-ref?        leafref 
            |  |  |  +--ro node-ref?      leafref 
            |  |  |  +--ro network-ref?   leafref 
            |  |  +--ro is-allowed?   boolean 
            |  +--ro domain-id?             uint32 
            |  +--ro flag*                  te-node-flag 
            |  +--ro is-abstract?           empty 
            |  +--ro name?                  inet:domain-name 
            |  +--ro signaling-address*     inet:ip-address 
            |  +--ro underlay-topology {te-topology-hierarchy}? 
            |     +--ro provider-id-ref?      leafref 
            |     +--ro client-id-ref?        leafref 
            |     +--ro te-topology-id-ref?   leafref 
            |     +--ro network-id-ref?       leafref 
            +--ro oper-status?                te-oper-status 
            +--ro is-multi-access-dr?         empty 
            +--ro information-source?         enumeration 
            +--ro information-source-state 
               +--ro credibility-preference?   uint16 
               +--ro topology 
               |  +--ro provider-id-ref?      leafref 
               |  +--ro client-id-ref?        leafref 
               |  +--ro te-topology-id-ref?   leafref 
               |  +--ro network-id-ref?       leafref 
               +--ro routing-instance?         string 
   augment /nw:network/nt:link: 
      +--rw te! 
         +--rw config 
         |  +--rw (bundle-stack-level)? 
         |  |  +--:(bundle) 
         |  |  |  +--rw bundled-links 
         |  |  |     +--rw bundled-link* [sequence] 
         |  |  |        +--rw sequence      uint32 
         |  |  |        +--rw src-tp-ref?   leafref 
         |  |  |        +--rw des-tp-ref?   leafref 
         |  |  +--:(component) 
         |  |     +--rw component-links 
         |  |        +--rw component-link* [sequence] 
         |  |           +--rw sequence             uint32 
         |  |           +--rw src-interface-ref?   string 
         |  |           +--rw des-interface-ref?   string 
         |  +--rw te-link-template*     leafref {template}? 
 
 
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         |  +--rw te-link-attributes 
         |     +--rw schedules 
         |     |  +--rw schedule* [schedule-id] 
         |     |     +--rw schedule-id          uint32 
         |     |     +--rw start?               yang:date-and-time 
         |     |     +--rw schedule-duration?   string 
         |     |     +--rw repeat-interval?     string 
         |     +--rw access-type?                      te-link-access-
   type 
         |     +--rw flag*                             te-link-flag 
         |     +--rw is-abstract?                      empty 
         |     +--rw name?                             string 
         |     +--rw underlay! {te-topology-hierarchy}? 
         |     |  +--rw underlay-primary-path 
         |     |  |  +--rw provider-id-ref?      leafref 
         |     |  |  +--rw client-id-ref?        leafref 
         |     |  |  +--rw te-topology-id-ref?   leafref 
         |     |  |  +--rw network-id-ref?       leafref 
         |     |  |  +--rw path-element* [path-element-id] 
         |     |  |     +--rw path-element-id     uint32 
         |     |  |     +--rw (type)? 
         |     |  |        +--:(ipv4-address) 
         |     |  |        |  +--rw v4-address?         inet:ipv4-
   address 
         |     |  |        |  +--rw v4-prefix-length?   uint8 
         |     |  |        |  +--rw v4-loose?           boolean 
         |     |  |        +--:(ipv6-address) 
         |     |  |        |  +--rw v6-address?         inet:ipv6-
   address 
         |     |  |        |  +--rw v6-prefix-length?   uint8 
         |     |  |        |  +--rw v6-loose?           boolean 
         |     |  |        +--:(as-number) 
         |     |  |        |  +--rw as-number?          uint16 
         |     |  |        +--:(unnumbered-link) 
         |     |  |        |  +--rw router-id?          inet:ip-address 
         |     |  |        |  +--rw interface-id?       uint32 
         |     |  |        +--:(label) 
         |     |  |           +--rw value?              uint32 
         |     |  +--rw underlay-backup-path* [index] 
         |     |  |  +--rw index                 uint32 
         |     |  |  +--rw provider-id-ref?      leafref 
         |     |  |  +--rw client-id-ref?        leafref 
         |     |  |  +--rw te-topology-id-ref?   leafref 
         |     |  |  +--rw network-id-ref?       leafref 
         |     |  |  +--rw path-element* [path-element-id] 
         |     |  |     +--rw path-element-id     uint32 
 
 
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         |     |  |     +--rw (type)? 
         |     |  |        +--:(ipv4-address) 
         |     |  |        |  +--rw v4-address?         inet:ipv4-
   address 
         |     |  |        |  +--rw v4-prefix-length?   uint8 
         |     |  |        |  +--rw v4-loose?           boolean 
         |     |  |        +--:(ipv6-address) 
         |     |  |        |  +--rw v6-address?         inet:ipv6-
   address 
         |     |  |        |  +--rw v6-prefix-length?   uint8 
         |     |  |        |  +--rw v6-loose?           boolean 
         |     |  |        +--:(as-number) 
         |     |  |        |  +--rw as-number?          uint16 
         |     |  |        +--:(unnumbered-link) 
         |     |  |        |  +--rw router-id?          inet:ip-address 
         |     |  |        |  +--rw interface-id?       uint32 
         |     |  |        +--:(label) 
         |     |  |           +--rw value?              uint32 
         |     |  +--rw underlay-protection-type?   uint16 
         |     |  +--rw underlay-trail-src 
         |     |  |  +--rw tp-ref?        leafref 
         |     |  |  +--rw node-ref?      leafref 
         |     |  |  +--rw network-ref?   leafref 
         |     |  +--rw underlay-trail-des 
         |     |     +--rw tp-ref?        leafref 
         |     |     +--rw node-ref?      leafref 
         |     |     +--rw network-ref?   leafref 
         |     +--rw admin-status?                     te-admin-status 
         |     +--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 

 
 
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         |     |  |  +--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 link-index?                       uint64 
         |     +--rw administrative-group?             te-types:admin-
   groups 
         |     +--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 

 
 
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         |     |  |  +--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-capability* [switching-
   capability] 
         |     |  +--rw switching-capability               identityref 
         |     |  +--rw encoding?                          identityref 
         |     |  +--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 interface-adjustment-capability* [upper-sc] 
         |     |     +--rw upper-sc             identityref 
         |     |     +--rw upper-encoding?      identityref 
         |     |     +--rw max-lsp-bandwidth* [priority] 
         |     |        +--rw priority     uint8 
         |     |        +--rw bandwidth?   decimal64 
         |     +--rw te-srlgs 
         |        +--rw values*   te-types:srlg 
         +--ro state 
 
 
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            +--ro (bundle-stack-level)? 
            |  +--:(bundle) 
            |  |  +--ro bundled-links 
            |  |     +--ro bundled-link* [sequence] 
            |  |        +--ro sequence      uint32 
            |  |        +--ro src-tp-ref?   leafref 
            |  |        +--ro des-tp-ref?   leafref 
            |  +--:(component) 
            |     +--ro component-links 
            |        +--ro component-link* [sequence] 
            |           +--ro sequence             uint32 
            |           +--ro src-interface-ref?   string 
            |           +--ro des-interface-ref?   string 
            +--ro te-link-template*           leafref {template}? 
            +--ro te-link-attributes 
            |  +--ro schedules 
            |  |  +--ro schedule* [schedule-id] 
            |  |     +--ro schedule-id          uint32 
            |  |     +--ro start?               yang:date-and-time 
            |  |     +--ro schedule-duration?   string 
            |  |     +--ro repeat-interval?     string 
            |  +--ro access-type?                      te-link-access-
   type 
            |  +--ro flag*                             te-link-flag 
            |  +--ro is-abstract?                      empty 
            |  +--ro name?                             string 
            |  +--ro underlay! {te-topology-hierarchy}? 
            |  |  +--ro underlay-primary-path 
            |  |  |  +--ro provider-id-ref?      leafref 
            |  |  |  +--ro client-id-ref?        leafref 
            |  |  |  +--ro te-topology-id-ref?   leafref 
            |  |  |  +--ro network-id-ref?       leafref 
            |  |  |  +--ro path-element* [path-element-id] 
            |  |  |     +--ro path-element-id     uint32 
            |  |  |     +--ro (type)? 
            |  |  |        +--:(ipv4-address) 
            |  |  |        |  +--ro v4-address?         inet:ipv4-
   address 
            |  |  |        |  +--ro v4-prefix-length?   uint8 
            |  |  |        |  +--ro v4-loose?           boolean 
            |  |  |        +--:(ipv6-address) 
            |  |  |        |  +--ro v6-address?         inet:ipv6-
   address 
            |  |  |        |  +--ro v6-prefix-length?   uint8 
            |  |  |        |  +--ro v6-loose?           boolean 
            |  |  |        +--:(as-number) 
 
 
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            |  |  |        |  +--ro as-number?          uint16 
            |  |  |        +--:(unnumbered-link) 
            |  |  |        |  +--ro router-id?          inet:ip-address 
            |  |  |        |  +--ro interface-id?       uint32 
            |  |  |        +--:(label) 
            |  |  |           +--ro value?              uint32 
            |  |  +--ro underlay-backup-path* [index] 
            |  |  |  +--ro index                 uint32 
            |  |  |  +--ro provider-id-ref?      leafref 
            |  |  |  +--ro client-id-ref?        leafref 
            |  |  |  +--ro te-topology-id-ref?   leafref 
            |  |  |  +--ro network-id-ref?       leafref 
            |  |  |  +--ro path-element* [path-element-id] 
            |  |  |     +--ro path-element-id     uint32 
            |  |  |     +--ro (type)? 
            |  |  |        +--:(ipv4-address) 
            |  |  |        |  +--ro v4-address?         inet:ipv4-
   address 
            |  |  |        |  +--ro v4-prefix-length?   uint8 
            |  |  |        |  +--ro v4-loose?           boolean 
            |  |  |        +--:(ipv6-address) 
            |  |  |        |  +--ro v6-address?         inet:ipv6-
   address 
            |  |  |        |  +--ro v6-prefix-length?   uint8 
            |  |  |        |  +--ro v6-loose?           boolean 
            |  |  |        +--:(as-number) 
            |  |  |        |  +--ro as-number?          uint16 
            |  |  |        +--:(unnumbered-link) 
            |  |  |        |  +--ro router-id?          inet:ip-address 
            |  |  |        |  +--ro interface-id?       uint32 
            |  |  |        +--:(label) 
            |  |  |           +--ro value?              uint32 
            |  |  +--ro underlay-protection-type?   uint16 
            |  |  +--ro underlay-trail-src 
            |  |  |  +--ro tp-ref?        leafref 
            |  |  |  +--ro node-ref?      leafref 
            |  |  |  +--ro network-ref?   leafref 
            |  |  +--ro underlay-trail-des 
            |  |     +--ro tp-ref?        leafref 
            |  |     +--ro node-ref?      leafref 
            |  |     +--ro network-ref?   leafref 
            |  +--ro admin-status?                     te-admin-status 
            |  +--ro performance-metric-throttle {te-performance-
   metric}? 
            |  |  +--ro unidirectional-delay-offset?           uint32 
            |  |  +--ro measure-interval?                      uint32 
 
 
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            |  |  +--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 
            |  |     +--ro unidirectional-available-bandwidth?   
   decimal64 
            |  |     +--ro unidirectional-utilized-bandwidth?    
   decimal64 
            |  +--ro link-index?                       uint64 
            |  +--ro administrative-group?             te-types:admin-
   groups 
            |  +--ro max-link-bandwidth?               decimal64 
            |  +--ro max-resv-link-bandwidth?          decimal64 
 
 
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            |  +--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-capability* [switching-
   capability] 
            |  |  +--ro switching-capability               identityref 
            |  |  +--ro encoding?                          identityref 
            |  |  +--ro max-lsp-bandwidth* [priority] 
            |  |  |  +--ro priority     uint8 
            |  |  |  +--ro bandwidth?   decimal64 
            |  |  +--ro packet-switch-capable 
            |  |  |  +--ro minimum-lsp-bandwidth?   decimal64 
            |  |  |  +--ro interface-mtu?           uint16 
 
 
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            |  |  +--ro time-division-multiplex-capable 
            |  |  |  +--ro minimum-lsp-bandwidth?   decimal64 
            |  |  |  +--ro indication?              enumeration 
            |  |  +--ro interface-adjustment-capability* [upper-sc] 
            |  |     +--ro upper-sc             identityref 
            |  |     +--ro upper-encoding?      identityref 
            |  |     +--ro max-lsp-bandwidth* [priority] 
            |  |        +--ro priority     uint8 
            |  |        +--ro bandwidth?   decimal64 
            |  +--ro te-srlgs 
            |     +--ro values*   te-types:srlg 
            +--ro oper-status?                te-oper-status 
            +--ro information-source?         enumeration 
            +--ro information-source-state 
            |  +--ro credibility-preference?   uint16 
            |  +--ro topology 
            |  |  +--ro provider-id-ref?      leafref 
            |  |  +--ro client-id-ref?        leafref 
            |  |  +--ro te-topology-id-ref?   leafref 
            |  |  +--ro network-id-ref?       leafref 
            |  +--ro routing-instance?         string 
            +--ro alt-information-sources* [information-source] 
            |  +--ro information-source                enumeration 
            |  +--ro information-source-state 
            |  |  +--ro credibility-preference?   uint16 
            |  |  +--ro topology 
            |  |  |  +--ro provider-id-ref?      leafref 
            |  |  |  +--ro client-id-ref?        leafref 
            |  |  |  +--ro te-topology-id-ref?   leafref 
            |  |  |  +--ro network-id-ref?       leafref 
            |  |  +--ro routing-instance?         string 
            |  +--ro link-index?                       uint64 
            |  +--ro administrative-group?             te-types:admin-
   groups 
            |  +--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 
 
 
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Internet-Draft            YANG - TE Topology               October 2015 
    

            |  |  |  +--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-capability* [switching-
   capability] 
            |  |  +--ro switching-capability               identityref 
            |  |  +--ro encoding?                          identityref 
            |  |  +--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 interface-adjustment-capability* [upper-sc] 
            |  |     +--ro upper-sc             identityref 
            |  |     +--ro upper-encoding?      identityref 
            |  |     +--ro max-lsp-bandwidth* [priority] 
            |  |        +--ro priority     uint8 
            |  |        +--ro bandwidth?   decimal64 
            |  +--ro te-srlgs 
 
 
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            |     +--ro values*   te-types:srlg 
            +--ro recovery 
            |  +--ro restoration-status?   te-recovery-status 
            |  +--ro protection-status?    te-recovery-status 
            +--ro underlay {te-topology-hierarchy}? 
               +--ro dynamic?     boolean 
               +--ro committed?   boolean 
   augment /nw:network/nw:node/nt:termination-point: 
      +--rw te! 
         +--rw te-tp-id    te-tp-id 
         +--rw config 
         |  +--rw schedules 
         |     +--rw schedule* [schedule-id] 
         |        +--rw schedule-id          uint32 
         |        +--rw start?               yang:date-and-time 
         |        +--rw schedule-duration?   string 
         |        +--rw repeat-interval?     string 
         +--ro state 
            +--ro schedules 
               +--ro schedule* [schedule-id] 
                  +--ro schedule-id          uint32 
                  +--ro start?               yang:date-and-time 
                  +--ro schedule-duration?   string 
                  +--ro repeat-interval?     string 
   notifications: 
      +---n te-node-event 
      |  +--ro event-type?                 te-topology-event-type 
      |  +--ro node-ref?                   leafref 
      |  +--ro network-ref?                leafref 
      |  +--ro te-topology! 
      |  +--ro te-node-attributes 
      |  |  +--ro schedules 
      |  |  |  +--ro schedule* [schedule-id] 
      |  |  |     +--ro schedule-id          uint32 
      |  |  |     +--ro start?               yang:date-and-time 
      |  |  |     +--ro schedule-duration?   string 
      |  |  |     +--ro repeat-interval?     string 
      |  |  +--ro admin-status?          te-admin-status 
      |  |  +--ro connectivity-matrix* [id] 
      |  |  |  +--ro id            uint32 
      |  |  |  +--ro from 
      |  |  |  |  +--ro tp-ref?        leafref 
      |  |  |  |  +--ro node-ref?      leafref 
      |  |  |  |  +--ro network-ref?   leafref 
      |  |  |  +--ro to 
      |  |  |  |  +--ro tp-ref?        leafref 
 
 
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      |  |  |  |  +--ro node-ref?      leafref 
      |  |  |  |  +--ro network-ref?   leafref 
      |  |  |  +--ro is-allowed?   boolean 
      |  |  +--ro domain-id?             uint32 
      |  |  +--ro flag*                  te-node-flag 
      |  |  +--ro is-abstract?           empty 
      |  |  +--ro name?                  inet:domain-name 
      |  |  +--ro signaling-address*     inet:ip-address 
      |  |  +--ro underlay-topology {te-topology-hierarchy}? 
      |  |     +--ro provider-id-ref?      leafref 
      |  |     +--ro client-id-ref?        leafref 
      |  |     +--ro te-topology-id-ref?   leafref 
      |  |     +--ro network-id-ref?       leafref 
      |  +--ro oper-status?                te-oper-status 
      |  +--ro is-multi-access-dr?         empty 
      |  +--ro information-source?         enumeration 
      |  +--ro information-source-state 
      |     +--ro credibility-preference?   uint16 
      |     +--ro topology 
      |     |  +--ro provider-id-ref?      leafref 
      |     |  +--ro client-id-ref?        leafref 
      |     |  +--ro te-topology-id-ref?   leafref 
      |     |  +--ro network-id-ref?       leafref 
      |     +--ro routing-instance?         string 
      +---n te-link-event 
         +--ro event-type?                 te-topology-event-type 
         +--ro link-ref?                   leafref 
         +--ro network-ref?                leafref 
         +--ro te-topology! 
         +--ro te-link-attributes 
         |  +--ro schedules 
         |  |  +--ro schedule* [schedule-id] 
         |  |     +--ro schedule-id          uint32 
         |  |     +--ro start?               yang:date-and-time 
         |  |     +--ro schedule-duration?   string 
         |  |     +--ro repeat-interval?     string 
         |  +--ro access-type?                      te-link-access-type 
         |  +--ro flag*                             te-link-flag 
         |  +--ro is-abstract?                      empty 
         |  +--ro name?                             string 
         |  +--ro underlay! {te-topology-hierarchy}? 
         |  |  +--ro underlay-primary-path 
         |  |  |  +--ro provider-id-ref?      leafref 
         |  |  |  +--ro client-id-ref?        leafref 
         |  |  |  +--ro te-topology-id-ref?   leafref 
         |  |  |  +--ro network-id-ref?       leafref 
 
 
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         |  |  |  +--ro path-element* [path-element-id] 
         |  |  |     +--ro path-element-id     uint32 
         |  |  |     +--ro (type)? 
         |  |  |        +--:(ipv4-address) 
         |  |  |        |  +--ro v4-address?         inet:ipv4-address 
         |  |  |        |  +--ro v4-prefix-length?   uint8 
         |  |  |        |  +--ro v4-loose?           boolean 
         |  |  |        +--:(ipv6-address) 
         |  |  |        |  +--ro v6-address?         inet:ipv6-address 
         |  |  |        |  +--ro v6-prefix-length?   uint8 
         |  |  |        |  +--ro v6-loose?           boolean 
         |  |  |        +--:(as-number) 
         |  |  |        |  +--ro as-number?          uint16 
         |  |  |        +--:(unnumbered-link) 
         |  |  |        |  +--ro router-id?          inet:ip-address 
         |  |  |        |  +--ro interface-id?       uint32 
         |  |  |        +--:(label) 
         |  |  |           +--ro value?              uint32 
         |  |  +--ro underlay-backup-path* [index] 
         |  |  |  +--ro index                 uint32 
         |  |  |  +--ro provider-id-ref?      leafref 
         |  |  |  +--ro client-id-ref?        leafref 
         |  |  |  +--ro te-topology-id-ref?   leafref 
         |  |  |  +--ro network-id-ref?       leafref 
         |  |  |  +--ro path-element* [path-element-id] 
         |  |  |     +--ro path-element-id     uint32 
         |  |  |     +--ro (type)? 
         |  |  |        +--:(ipv4-address) 
         |  |  |        |  +--ro v4-address?         inet:ipv4-address 
         |  |  |        |  +--ro v4-prefix-length?   uint8 
         |  |  |        |  +--ro v4-loose?           boolean 
         |  |  |        +--:(ipv6-address) 
         |  |  |        |  +--ro v6-address?         inet:ipv6-address 
         |  |  |        |  +--ro v6-prefix-length?   uint8 
         |  |  |        |  +--ro v6-loose?           boolean 
         |  |  |        +--:(as-number) 
         |  |  |        |  +--ro as-number?          uint16 
         |  |  |        +--:(unnumbered-link) 
         |  |  |        |  +--ro router-id?          inet:ip-address 
         |  |  |        |  +--ro interface-id?       uint32 
         |  |  |        +--:(label) 
         |  |  |           +--ro value?              uint32 
         |  |  +--ro underlay-protection-type?   uint16 
         |  |  +--ro underlay-trail-src 
         |  |  |  +--ro tp-ref?        leafref 
         |  |  |  +--ro node-ref?      leafref 
 
 
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         |  |  |  +--ro network-ref?   leafref 
         |  |  +--ro underlay-trail-des 
         |  |  |  +--ro tp-ref?        leafref 
         |  |  |  +--ro node-ref?      leafref 
         |  |  |  +--ro network-ref?   leafref 
         |  |  +--ro dynamic?                    boolean 
         |  |  +--ro committed?                  boolean 
         |  +--ro admin-status?                     te-admin-status 
         |  +--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 
         |  |     +--ro unidirectional-available-bandwidth?   decimal64 
         |  |     +--ro unidirectional-utilized-bandwidth?    decimal64 
         |  +--ro link-index?                       uint64 
         |  +--ro administrative-group?             te-types:admin-
   groups 
         |  +--ro max-link-bandwidth?               decimal64 
         |  +--ro max-resv-link-bandwidth?          decimal64 
         |  +--ro unreserved-bandwidth* [priority] 
 
 
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         |  |  +--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-capability* [switching-
   capability] 
         |  |  +--ro switching-capability               identityref 
         |  |  +--ro encoding?                          identityref 
         |  |  +--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 interface-adjustment-capability* [upper-sc] 
         |  |     +--ro upper-sc             identityref 
 
 
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         |  |     +--ro upper-encoding?      identityref 
         |  |     +--ro max-lsp-bandwidth* [priority] 
         |  |        +--ro priority     uint8 
         |  |        +--ro bandwidth?   decimal64 
         |  +--ro te-srlgs 
         |     +--ro values*   te-types:srlg 
         +--ro oper-status?                te-oper-status 
         +--ro information-source?         enumeration 
         +--ro information-source-state 
         |  +--ro credibility-preference?   uint16 
         |  +--ro topology 
         |  |  +--ro provider-id-ref?      leafref 
         |  |  +--ro client-id-ref?        leafref 
         |  |  +--ro te-topology-id-ref?   leafref 
         |  |  +--ro network-id-ref?       leafref 
         |  +--ro routing-instance?         string 
         +--ro alt-information-sources* [information-source] 
         |  +--ro information-source                enumeration 
         |  +--ro information-source-state 
         |  |  +--ro credibility-preference?   uint16 
         |  |  +--ro topology 
         |  |  |  +--ro provider-id-ref?      leafref 
         |  |  |  +--ro client-id-ref?        leafref 
         |  |  |  +--ro te-topology-id-ref?   leafref 
         |  |  |  +--ro network-id-ref?       leafref 
         |  |  +--ro routing-instance?         string 
         |  +--ro link-index?                       uint64 
         |  +--ro administrative-group?             te-types:admin-
   groups 
         |  +--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 
 
 
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         |  |     +--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-capability* [switching-
   capability] 
         |  |  +--ro switching-capability               identityref 
         |  |  +--ro encoding?                          identityref 
         |  |  +--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 interface-adjustment-capability* [upper-sc] 
         |  |     +--ro upper-sc             identityref 
         |  |     +--ro upper-encoding?      identityref 
         |  |     +--ro max-lsp-bandwidth* [priority] 
         |  |        +--ro priority     uint8 
         |  |        +--ro bandwidth?   decimal64 
         |  +--ro te-srlgs 
         |     +--ro values*   te-types:srlg 
         +--ro recovery 
         |  +--ro restoration-status?   te-recovery-status 
         |  +--ro protection-status?    te-recovery-status 
         +--ro underlay {te-topology-hierarchy}? 
            +--ro dynamic?     boolean 
            +--ro committed?   boolean 
    

 
 
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6. TE Topology Yang Module 

   <CODE BEGINS> 

   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-inet-types { 
       prefix "inet"; 
     } 
    
     import ietf-schedule {  
       prefix "sch";  
     } 
    
     import ietf-te-types { 
       prefix "te-types"; 
     } 
    
     import ietf-network { 
       prefix "nw"; 
     } 
    
     import ietf-network-topology { 
       prefix "nt"; 
     } 
    
     organization "TBD"; 
     contact "TBD"; 
     description "TE topology model"; 
      
     revision "2015-10-16" { 
       description "Initial revision"; 
       reference "TBD"; 
     } 
    
     /* 
      * Features 
      */ 
    
     feature configuration-schedule { 
       description 
 
 
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         "This feature indicates that the system supports  
          configuration scheduling."; 
     } 
    
     feature te-topology-hierarchy { 
       description 
         "This feature indicates that the system allows underlay 
          and/or overlay TE topology hierarchy."; 
     } 
    
     feature te-performance-metric { 
       description 
         "This feature indicates that the system supports 
          TE performance metric defined in 
          RFC7471: OSPF Traffic Engineering (TE) Metric Extensions."; 
     } 
    
     feature template { 
       description 
         "This feature indicates that the system supports  
          template configuration."; 
     } 
    
     /* 
      * Typedefs 
      */ 
     typedef performance-metric-normality { 
       type enumeration { 
         enum "unknown" {         
           value 0; 
           description 
             "Unknown."; 
         } 
         enum "normal" {         
           value 1; 
           description 
             "Normal."; 
         } 
         enum "abnormal" {         
           value 2; 
           description 
             "Abnormal. The anomalous bit is set."; 
         } 
       } 
       description 
         "Indicates whether a performance metric is normal, abnormal,  
 
 
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          or unknown."; 
       reference 
         "RFC7471: OSPF Traffic Engineering (TE) Metric Extensions."; 
     } 
    
     typedef te-admin-status { 
       type enumeration { 
         enum up { 
           description 
             "Enabled."; 
         } 
         enum down { 
           description 
             "Disabled."; 
         } 
         enum testing { 
           description 
             "In some test mode."; 
         } 
         enum preparing-maintenance { 
           description 
             "Resource is disabled in the control plane to prepare for 
              graceful shutdown for maintenance purposes."; 
           reference 
             "RFC5817: Graceful Shutdown in MPLS and Generalized MPLS 
              Traffic Engineering Networks"; 
         } 
         enum maintenance { 
           description 
             "Resource is disabled in the data plane for maintenance 
              purposes."; 
         } 
       } 
       description 
         "Defines a type representing the administrative status of  
          a TE resource."; 
     } 
    
     typedef te-global-id { 
       type uint32; 
       description 
         "An identifier to uniquely identify an operator, which can be 
          either a provider or a client. 
          The definition of this type is taken from RFC6370 and  
          RFC5003. This attribute type is used solely to provide a  
          globally unique context for TE topologies."; 
 
 
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     } 
    
     typedef te-link-access-type { 
       type enumeration { 
         enum point-to-point { 
           description 
             "The link is point-to-point."; 
         } 
         enum multi-access { 
           description 
             "The link is multi-access, including broacast and NBMA."; 
         } 
       } 
       description 
         "Defines a type representing the access type of a TE link."; 
       reference 
         "RFC3630: Traffic Engineering (TE) Extensions to OSPF 
          Version 2."; 
     } 
    
     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. 
          This attribute is mapped to Router ID in 
          RFC3630, RFC5329, RFC5305, and RFC 6119."; 
     } 
    
     typedef te-oper-status { 
       type enumeration { 
         enum up { 
           description 
           "Operational up."; 
         } 
         enum down { 
           description 
           "Operational down."; 
         } 
         enum testing { 
           description 
           "In some test mode."; 
         } 
         enum unknown { 
           description 
           "Status cannot be determined for some reason."; 
 
 
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         } 
         enum preparing-maintenance { 
           description 
             "Resource is disabled in the control plane to prepare for 
              graceful shutdown for maintenance purposes."; 
           reference 
             "RFC5817: Graceful Shutdown in MPLS and Generalized MPLS 
              Traffic Engineering Networks"; 
         } 
         enum maintenance { 
           description 
             "Resource is disabled in the data plane for maintenance 
              purposes."; 
         } 
       } 
       description 
         "Defines a type representing the operational status of  
          a TE resource."; 
     } 
    
     typedef te-recovery-status { 
       type enumeration { 
         enum normal { 
           description 
             "Both the recovery and working spans are fully 
              allocated and active, data traffic is being 
              transported over (or selected from) the working 
              span, and no trigger events are reported."; 
         } 
         enum recovery-started { 
           description 
             "The recovery action has been started, but not  
              completed."; 
         } 
         enum recovery-succeeded { 
           description 
             "The recovery action has succeeded. The working span has 
              reported a failure/degrade condition and the user traffic 
              is being transported (or selected) on the recovery  
              span."; 
         } 
         enum recovery-failed { 
           description 
             "The recovery action has failed."; 
         } 
         enum reversion-started { 
 
 
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           description 
             "The reversion has started."; 
         } 
         enum reversion-failed { 
           description 
             "The reversion has failed."; 
         } 
         enum recovery-unavailable { 
           description 
             "The recovery is unavailable -- either as a result of an 
              operator Lockout command or a failure condition detected 
              on the recovery span."; 
         } 
         enum recovery-admin { 
           description 
             "The operator has issued a command switching the user 
              traffic to the recovery span."; 
         } 
         enum wait-to-restore { 
           description 
             "The recovery domain is recovering from a failuer/degrade 
              condition on the working span that is being controlled by 
              the Wait-to-Restore (WTR) timer."; 
         } 
       } 
       description 
         "Defines the status of a recovery action."; 
       reference 
         "RFC4427: Recovery (Protection and Restoration) Terminology 
          for Generalized Multi-Protocol Label Switching (GMPLS). 
          RFC6378: MPLS Transport Profile (MPLS-TP) Linear Protection"; 
     } 
    
     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-topology-event-type { 
       type enumeration { 
         enum "add" { 
           value 0; 
 
 
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           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."; 
         } 
       } 
       description "TE  Event type for notifications"; 
     } // te-topology-event-type 
      
     typedef te-topology-id { 
       type string { 
         pattern '/?([a-zA-Z0-9\-_.]+)(/[a-zA-Z0-9\-_.]+)*'; 
       } 
       description 
         "An identifier for a topology."; 
     } 
      
     typedef te-tp-id { 
       type union { 
         type uint32;          // Unnumbered 
         type inet:ip-address; // IPv4 or IPv6 address 
       } 
       description 
         "An identifier for a TE link endpoint on a node. 
          This attribute is mapped to local or remote link identifier  
          in RFC3630 and RFC5305."; 
     } 
      
     /* 
      * Identities 
      */ 
    
     identity te-flag-base { 
       description "Base type for flags."; 
     } 
    
     identity te-link-flag { 
       base "te-flag-base"; 
 
 
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       description "TE link flag."; 
     } 
      
     identity te-node-flag { 
       base "te-flag-base"; 
       description "TE node flag."; 
     } 
    
     identity te-undefined-flag { 
       base "te-flag-base"; 
       description "Undefined flag."; 
     } 
    
     typedef te-node-flag { 
       type identityref { 
         base "te-node-flag"; 
       } 
       description "Type for TE node flags."; 
     } 
    
     typedef te-link-flag { 
       type identityref { 
         base "te-link-flag"; 
       } 
       description "Type for TE link flags."; 
     } 
    
     /* 
      * Groupings 
      */ 
     grouping network-ref { 
       description 
         "Contains the information necessary to reference a network, 
          for example an underlay network."; 
       leaf network-ref { 
         type leafref { 
           path "/nw:network/nw:network-id"; 
         } 
         description 
           "Used to reference a network, for example an underlay 
            network."; 
       } 
     } 
    
     grouping node-ref { 
       description  
 

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         "Contains the information necessary to reference a node."; 
       leaf node-ref { 
         type leafref { 
           path "/nw:network[nw:network-id=current()/../network-ref]"+ 
             "/nw:node/nw:node-id"; 
         } 
         description 
           "Used to reference a node.   
            Nodes are identified relative to the network they are 
            contained in."; 
       } 
       uses network-ref; 
     } 
    
     grouping link-ref { 
       description 
         "References a link in a specific network."; 
       leaf link-ref { 
         type leafref { 
           path "/nw:network[nw:network-id=current()/../"+ 
             "network-ref]/nt:link/nt:link-id"; 
         } 
         description 
           "A type for an absolute reference a link instance. 
            (This type should not be used for relative references. 
            In such a case, a relative path should be used instead.)"; 
       } 
       uses network-ref; 
     } 
    
     grouping tp-ref { 
       description 
         "References a termination point in a specific node."; 
       leaf tp-ref { 
         type leafref { 
           path "/nw:network[nw:network-id=current()/../"+ 
             "network-ref]/nw:node[nw:node-id=current()/../"+ 
             "node-ref]/nt:termination-point/nt:tp-id"; 
         } 
         description 
           "A type for an absolute reference to a termination point. 
            (This type should not be used for relative references. 
            In such a case, a relative path should be used instead.)"; 
       } 
       uses node-ref; 
     } 
 
  
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     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 entity."; 
           } 
           enum "ospfv2" { 
             description "OSPFv2."; 
           } 
           enum "ospfv3" { 
             description "OSPFv3."; 
           } 
           enum "isis" { 
             description "ISIS."; 
           } 
           enum "system-processed" { 
             description "System processed entity."; 
           } 
           enum "other" { 
             description "Other source."; 
           } 
         } 
         description  
           "Indicates the source of the information."; 
       } 
       container information-source-state { 
         description 
           "The container contains state attributes related to  
            the information source."; 
         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."; 
         }       
         container topology { 
 
 
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           description  
             "When the information is processed by the system, 
              the attributes in this container indicate which topology 
              is used to process to generate the result information."; 
           uses te-topology-ref; 
         } // topology 
         leaf routing-instance { 
           type string; 
           description 
             "When applicable, this is the name of a routing instance 
              from which the information is learned."; 
         } // routing-information 
       } 
     } // information-source-attributes 
    
     grouping performance-metric-attributes { 
       description 
         "Link performance information in real time."; 
       reference  
         "RFC7471: OSPF Traffic Engineering (TE) Metric Extensions."; 
       leaf unidirectional-delay { 
         type uint32 { 
           range 0..16777215; 
         } 
         description "Delay or latency in micro seconds."; 
       } 
       leaf unidirectional-min-delay { 
         type uint32 { 
           range 0..16777215; 
         } 
         description "Minimum delay or latency in micro seconds."; 
       } 
       leaf unidirectional-max-delay { 
         type uint32 { 
           range 0..16777215; 
         } 
         description "Maximum delay or latency in micro seconds."; 
       } 
       leaf unidirectional-delay-variation { 
         type uint32 { 
           range 0..16777215; 
         } 
         description "Delay variation in micro seconds."; 
       } 
       leaf unidirectional-packet-loss { 
         type decimal64 { 
 
 
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           fraction-digits 6; 
           range "0 .. 50.331642"; 
         } 
         description  
           "Packet loss as a percentage of the total traffic sent 
            over a configurable interval. The finest precision is 
            0.000003%."; 
       } 
       leaf unidirectional-residual-bandwidth { 
         type decimal64 { 
           fraction-digits 2; 
         } 
         description  
           "Residual bandwidth that subtracts tunnel 
            reservations from Maximum Bandwidth (or link capacity) 
            [RFC3630] and provides an aggregated remainder across QoS 
            classes."; 
       } 
       leaf unidirectional-available-bandwidth { 
         type decimal64 { 
           fraction-digits 2; 
         } 
         description  
           "Available bandwidth that is defined to be residual 
            bandwidth minus the measured bandwidth used for the 
            actual forwarding of non-RSVP-TE LSP packets.  For a 
            bundled link, available bandwidth is defined to be the 
            sum of the component link available bandwidths."; 
       } 
       leaf unidirectional-utilized-bandwidth { 
         type decimal64 { 
           fraction-digits 2; 
         } 
         description 
           "Bandwidth utilization that represents the actual 
            utilization of the link (i.e. as measured in the router). 
            For a bundled link, bandwidth utilization is defined to 
            be the sum of the component link bandwidth 
            utilizations."; 
       } 
     } // performance-metric-attributes 
    
     grouping performance-metric-normality-attributes { 
       description 
         "Link performance metric normality attributes."; 
       reference  
 
 
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         "RFC7471: OSPF Traffic Engineering (TE) Metric Extensions."; 
       leaf unidirectional-delay { 
         type performance-metric-normality; 
         description "Delay normality."; 
       } 
       leaf unidirectional-min-delay { 
         type performance-metric-normality; 
         description "Minimum delay or latency normality."; 
       } 
       leaf unidirectional-max-delay { 
         type performance-metric-normality; 
         description "Maximum delay or latency normality."; 
       } 
       leaf unidirectional-delay-variation { 
         type performance-metric-normality; 
         description "Delay variation normality."; 
       } 
       leaf unidirectional-packet-loss { 
         type performance-metric-normality; 
         description "Packet loss normality."; 
       } 
       leaf unidirectional-residual-bandwidth { 
         type performance-metric-normality; 
         description "Residual bandwidth normality."; 
       } 
       leaf unidirectional-available-bandwidth { 
         type performance-metric-normality; 
         description "Available bandwidth normality."; 
       } 
       leaf unidirectional-utilized-bandwidth { 
         type performance-metric-normality; 
         description "Bandwidth utilization normality."; 
       } 
     } // performance-metric-normality-attributes 
    
     grouping performance-metric-throttle-container { 
       description 
         "A container controlling performance metric throttle."; 
       container performance-metric-throttle { 
         if-feature te-performance-metric; 
         must "suppression-interval >= measure-interval" { 
           error-message  
             "suppression-interval cannot be less then  
              measure-interval."; 
           description 
             "Constraint on suppression-interval and  
 
  
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              measure-interval."; 
         } 
         description 
           "Link performance information in real time."; 
         reference  
           "RFC7471: OSPF Traffic Engineering (TE) Metric Extensions."; 
         leaf unidirectional-delay-offset { 
           type uint32 { 
             range 0..16777215; 
           } 
           description  
             "Offset value to be added to the measured delay value."; 
         } 
         leaf measure-interval { 
           type uint32; 
           default 30; 
           description  
             "Interval in seconds to measure the extended metric 
              values."; 
         } 
         leaf advertisement-interval { 
           type uint32; 
           description  
             "Interval in seconds to advertise the extended metric 
              values."; 
         } 
         leaf suppression-interval { 
           type uint32 { 
             range "1 .. max"; 
           } 
           default 120; 
           description  
             "Interval in seconds to suppress advertising the extended 
              metric values."; 
         } 
         container threshold-out { 
           uses performance-metric-attributes; 
           description 
             "If the measured parameter falls outside an upper bound 
              for all but the min delay metric (or lower bound for 
              min-delay metric only) and the advertised value is not 
              already outside that bound, anomalous announcement will  
              be triggered."; 
         } 
         container threshold-in { 
           uses performance-metric-attributes; 
 
  
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           description 
             "If the measured parameter falls inside an upper bound 
              for all but the min delay metric (or lower bound for 
              min-delay metric only) and the advertised value is not 
              already inside that bound, normal (anomalous-flag  
              cleared) announcement will be triggered."; 
         } 
         container threshold-accelerated-advertisement { 
           description 
             "When the difference between the last advertised value and 
              current measured value exceed this threshold, anomalous 
              announcement will be triggered."; 
           uses performance-metric-attributes; 
         } 
       } 
     } // performance-metric-throttle-container 
    
     grouping te-link-augment { 
       description  
         "Augmentatin for TE link."; 
        
       container te { 
         presence "TE support."; 
         description  
           "Indicates TE support."; 
    
         container config { 
           description 
             "Configuration data."; 
           uses te-link-config; 
         } // config 
         container state { 
           config false; 
           description 
             "Operational state data."; 
           uses te-link-config; 
           uses te-link-state-derived; 
         } // state 
       } // te 
     } // te-link-augment 
      
     grouping te-link-config { 
       description 
         "TE link configuration grouping."; 
       choice bundle-stack-level { 
         description  
 
 
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           "The TE link can be partitioned into bundled 
            links, or component links."; 
         case bundle { 
           container bundled-links { 
             description 
               "A set of bundled links."; 
             reference 
               "RFC4201: Link Bundling in MPLS Traffic Engineering 
               (TE)."; 
             list bundled-link { 
               key "sequence"; 
               description 
                 "Specify a bundled interface that is 
                  further partitioned."; 
               leaf sequence { 
                 type uint32; 
                 description 
                   "Identify the sequence in the bundle."; 
               } 
               leaf src-tp-ref { 
                 type leafref { 
                   path "../../../../../../nw:node[nw:node-id = " 
                     + "current()/../../../../../nt:source/" 
                     + "nt:source-node]/" 
                     + "nt:termination-point/nt:tp-id"; 
                   require-instance true; 
                 } 
                 description 
                   "Reference to another TE termination point on the 
                    same souruce node."; 
               } 
               leaf des-tp-ref { 
                 type leafref { 
                   path "../../../../../../nw:node[nw:node-id = " 
                     + "current()/../../../../../nt:destination/" 
                     + "nt:dest-node]/" 
                     + "nt:termination-point/nt:tp-id"; 
                   require-instance true; 
                 } 
                 description 
                   "Reference to another TE termination point on the 
                    same destination node."; 
               } 
             } // list bundled-link 
           } 
         } 
 
 
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         case component { 
           container component-links { 
             description 
               "A set of component links"; 
             list component-link { 
               key "sequence"; 
               description 
                 "Specify a component interface that is 
                  sufficient to unambiguously identify the 
                  appropriate resources"; 
                
               leaf sequence { 
                 type uint32; 
                 description 
                   "Identify the sequence in the bundle."; 
               } 
               leaf src-interface-ref { 
                 type string; 
                 description 
                   "Reference to component link interface on the 
                    source node."; 
               } 
               leaf des-interface-ref { 
                 type string; 
                 description 
                   "Reference to component link interface on the 
                    destinatioin node."; 
               } 
             } 
           } 
         } 
       } // bundle-stack-level 
        
       leaf-list te-link-template { 
         if-feature template; 
         type leafref { 
           path "../../../../te/templates/link-template/name"; 
         } 
         description 
           "The reference to a TE link template."; 
       } 
       uses te-link-config-attributes; 
     } // te-link-config 
    
     grouping te-link-config-attributes { 
       description  
 
 
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         "Link configuration attributes in a TE topology."; 
       container te-link-attributes { 
         description "Link attributes in a TE topology."; 
         uses sch:schedules; 
         leaf access-type { 
           type te-link-access-type; 
           description  
             "Link access type, which can be point-to-point or 
              multi-access."; 
         } 
         leaf-list flag { 
           type te-link-flag; 
           description "Link flags."; 
         } 
         leaf is-abstract { 
           type empty; 
           description "Present if the link is abstract."; 
         } 
         leaf name { 
           type string; 
           description "Link Name."; 
         } 
         container underlay { 
           if-feature te-topology-hierarchy; 
           presence  
             "Indicates the underlay exists for this link."; 
           description "Attributes of the te-link underlay."; 
           reference 
             "RFC4206: Label Switched Paths (LSP) Hierarchy with 
              Generalized Multi-Protocol Label Switching (GMPLS) 
              Traffic Engineering (TE)"; 
    
           uses te-link-underlay-attributes; 
         } // underlay 
         leaf admin-status { 
           type te-admin-status; 
           description 
             "The administrative state of the link."; 
         } 
          
         uses performance-metric-throttle-container; 
         uses te-link-info-attributes; 
       } 
     } // te-link-config-attributes 
    
     grouping te-link-info-attributes { 
 
 
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       description 
         "Advertised TE information attributes."; 
       leaf link-index { 
         type uint64; 
         description 
           "The link identifier.  If OSPF is used, this represents an 
            ospfLsdbID.  If IS-IS is used, this represents an  
            isisLSPID. If a locally configured link is used, this  
            object represents a unique value, which is locally defined  
            in a router."; 
       } 
       leaf administrative-group { 
         type te-types:admin-groups; 
         description 
           "Administrative group or color of the link.  
            This attribute covers both administrative group (defined in 
            RFC3630, RFC5329, and RFC5305), and extended administrative 
            group (defined in RFC7308)."; 
       } 
       leaf max-link-bandwidth { 
         type decimal64 { 
           fraction-digits 2; 
         } 
         description 
           "Maximum bandwidth that can be seen on this link in this 
            direction. Units in bytes per second."; 
         reference 
           "RFC3630: Traffic Engineering (TE) Extensions to OSPF 
            Version 2. 
            RFC5305: IS-IS Extensions for Traffic Engineering."; 
       } 
       leaf max-resv-link-bandwidth { 
         type decimal64 { 
           fraction-digits 2; 
         } 
         description 
           "Maximum amount of bandwidth that can be reserved in this 
            direction in this link. Units in bytes per second."; 
         reference 
           "RFC3630: Traffic Engineering (TE) Extensions to OSPF 
            Version 2. 
            RFC5305: IS-IS Extensions for Traffic Engineering."; 
       } 
       list unreserved-bandwidth { 
         key "priority"; 
         max-elements "8"; 
 
 
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         description 
           "Unreserved bandwidth for 0-7 priority levels. Units in 
            bytes per second."; 
         reference 
           "RFC3630: Traffic Engineering (TE) Extensions to OSPF 
            Version 2. 
            RFC5305: IS-IS Extensions for Traffic Engineering."; 
         leaf priority { 
           type uint8 { 
             range "0..7"; 
           } 
           description "Priority."; 
         } 
         leaf bandwidth { 
           type decimal64 { 
             fraction-digits 2; 
           } 
           description 
             "Unreserved bandwidth for this level."; 
         } 
       } 
       leaf te-default-metric { 
         type uint32; 
         description 
           "Traffic Engineering Metric."; 
       } 
       container performance-metric { 
         if-feature te-performance-metric; 
         description 
           "Link performance information in real time."; 
         reference  
           "RFC7471: OSPF Traffic Engineering (TE) Metric Extensions."; 
         container measurement { 
           description 
             "Measured performance metric values. Static configuration 
              and manual overrides of these measurements are also  
              allowed."; 
           uses performance-metric-attributes; 
         } 
         container normality 
         { 
           description 
             "Performance metric normality values."; 
           uses performance-metric-normality-attributes; 
         } 
       } 
 
 
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       leaf link-protection-type { 
         type enumeration { 
           enum "unprotected" { 
             description "Unprotected."; 
           } 
           enum "extra-traffic" { 
             description "Extra traffic."; 
           } 
           enum "shared" { 
             description "Shared."; 
           } 
           enum "1-for-1" { 
             description "One for one protection."; 
           } 
           enum "1-plus-1" { 
             description "One plus one protection."; 
           } 
           enum "enhanced" { 
             description "Enhanced protection."; 
           } 
         } 
         description 
           "Link Protection Type desired for this link."; 
         reference 
           "RFC4202: Routing Extensions in Support of 
            Generalized Multi-Protocol Label Switching (GMPLS)."; 
       } 
       list interface-switching-capability { 
         key "switching-capability"; 
         description 
           "List of Interface Switching Capabilities Descriptors (ISCD) 
            for this link."; 
         reference 
           "RFC3471: Generalized Multi-Protocol Label Switching (GMPLS) 
            Signaling Functional Description. 
            RFC4203: OSPF Extensions in Support of Generalized  
            Multi-Protocol Label Switching (GMPLS)."; 
         leaf switching-capability { 
           type identityref { 
             base te-types:switching-capabilities; 
           } 
           description 
             "Switching Capability for this interface."; 
         } 
         leaf encoding { 
           type identityref { 
 
 
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             base te-types:lsp-encoding-types; 
           } 
           description 
             "Encoding supported by this interface."; 
         } 
         list max-lsp-bandwidth { 
           key "priority"; 
           max-elements "8"; 
           description 
             "Maximum LSP Bandwidth at priorities 0-7."; 
           leaf priority { 
             type uint8 { 
               range "0..7"; 
             } 
             description "Priority."; 
           } 
           leaf bandwidth { 
             type decimal64 { 
               fraction-digits 2; 
             } 
             description 
               "Max LSP Bandwidth for this level"; 
           } 
         } 
         container packet-switch-capable { 
           when "../switching-capability = 'PSC-1'  or " 
             +"../switching-capability = 'PSC-2' or " 
             +"../switching-capability = 'PSC-3' or " 
             +"../switching-capability = 'PSC-4'" { 
             description "Valid only for PSC"; 
           } 
           description 
             "Interface has packet-switching capabilities."; 
           leaf minimum-lsp-bandwidth { 
             type decimal64 { 
               fraction-digits 2; 
             } 
             description 
               "Minimum LSP Bandwidth. Units in bytes per second"; 
           } 
           leaf interface-mtu { 
             type uint16; 
             description 
               "Interface MTU."; 
           } 
         } 
 
 
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         container time-division-multiplex-capable { 
           when "../switching-capability = 'TDM'" { 
             description "Valid only for TDM"; 
           } 
           description 
             "Interface has time-division multiplex capabilities."; 
    
           leaf minimum-lsp-bandwidth { 
             type decimal64 { 
               fraction-digits 2; 
             } 
             description 
               "Minimum LSP Bandwidth. Units in bytes per second."; 
           } 
           leaf indication { 
             type enumeration { 
               enum "standard" { 
                 description  
                   "Indicates support of standard SONET/SDH."; 
               } 
               enum "arbitrary" { 
                 description  
                   "Indicates support of arbitrary SONET/SDH."; 
               } 
             } 
             description 
               "Indication whether the interface supports Standard or 
                Arbitrary SONET/SDH"; 
           } 
         } 
         list interface-adjustment-capability { 
           key "upper-sc"; 
           description 
             "List of Interface Adjustment Capability Descriptors  
              (IACD)for this link."; 
           reference 
             "RFC6001: Generalized MPLS (GMPLS) Protocol Extensions 
              for Multi-Layer and Multi-Region Networks (MLN/MRN)."; 
           leaf upper-sc { 
             type identityref { 
               base te-types:switching-capabilities; 
             } 
             description 
               "Switching Capability for this interface."; 
           } 
           leaf upper-encoding { 
 
 
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             type identityref { 
               base te-types:lsp-encoding-types; 
             } 
             description 
               "Encoding supported by this interface."; 
           } 
           list max-lsp-bandwidth { 
             key "priority"; 
             max-elements "8"; 
             description 
               "Maximum LSP Bandwidth at priorities 0-7."; 
             leaf priority { 
               type uint8 { 
                 range "0..7"; 
               } 
               description "Priority."; 
             } 
             leaf bandwidth { 
               type decimal64 { 
                 fraction-digits 2; 
               } 
               description 
                 "Max LSP Bandwidth for this level."; 
             } 
           } 
         } // interface-adjustment-capability 
       } // interface-switching-capability 
       container te-srlgs { 
         description 
           "A list of SLRGs."; 
         leaf-list values { 
           type te-types:srlg; 
           description "SRLG value."; 
           reference 
             "RFC4202: Routing Extensions in Support of 
              Generalized Multi-Protocol Label Switching (GMPLS)."; 
         } 
       } 
     } // te-link-info-attributes 
    
     grouping te-link-state-derived { 
       description  
         "Link state attributes in a TE topology."; 
       leaf oper-status { 
         type te-oper-status; 
         description 
 
 
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           "The current operational state of the link."; 
       } 
       uses information-source-attributes; 
       list alt-information-sources { 
         key "information-source"; 
         description 
           "A list of information sources learned but not used."; 
         uses information-source-attributes; 
         uses te-link-info-attributes; 
       } 
       container recovery { 
         description 
           "Status of the recovery process."; 
         leaf restoration-status { 
           type te-recovery-status; 
           description 
             "Restoration status."; 
         } 
         leaf protection-status { 
           type te-recovery-status; 
           description 
             "Protection status."; 
         }       
       } 
       container underlay { 
         if-feature te-topology-hierarchy; 
         description "State attributes for te-link underlay."; 
         uses te-link-state-underlay-attributes; 
       } 
     } // te-link-state-derived 
    
     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-underlay-attributes { 
 
 
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       description "Attributes for  te-link underlay."; 
       reference 
         "RFC4206: Label Switched Paths (LSP) Hierarchy with 
          Generalized Multi-Protocol Label Switching (GMPLS) 
          Traffic Engineering (TE)"; 
       container underlay-primary-path { 
         description  
           "The service path on the underlay topology that 
            supports this link."; 
         uses te-topology-ref; 
         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-primary-path 
       list underlay-backup-path { 
         key "index"; 
         description  
           "A list of backup service paths on the underlay topology  
            that protect the underlay primary path. If the primary path  
            is not protected, the list contains zero elements. If the  
            primary path is protected, the list contains one or more 
            elements."; 
         leaf index { 
           type uint32; 
           description 
             "A sequence number to identify a backup path."; 
         } 
         uses te-topology-ref; 
         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; 
         } 
 
 
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       } // underlay-backup-path 
       leaf underlay-protection-type { 
         type uint16; 
         description 
           "Underlay protection type desired for this link"; 
       } 
       container underlay-trail-src { 
         uses tet:tp-ref; 
         description 
           "Source TE link of the underlay trail."; 
       } 
       container underlay-trail-des { 
         uses tet:tp-ref; 
         description 
           "Destination TE link of the underlay trail."; 
       } 
     } // te-link-underlay-attributes 
    
     grouping te-node-augment { 
       description 
         "Augmentatin for TE node."; 
        
       container te { 
         presence "TE support."; 
         description  
           "Indicates TE support."; 
    
         leaf te-node-id { 
           type te-node-id; 
           mandatory true; 
           description 
             "The identifier of a node in the TE topology. 
              A node is specific to a topology to which it belongs."; 
         } 
    
         container config { 
           description 
             "Configuration data."; 
           uses te-node-config; 
         } // config 
         container state { 
           config false; 
           description 
             "Operational state data."; 
    
           uses te-node-config; 
 
  
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           uses te-node-state-derived; 
         } // state 
       } // te 
     } // te-node-augment 
    
     grouping te-node-config { 
       description "TE node configuration grouping."; 
    
       leaf-list te-node-template { 
         if-feature template; 
         type leafref { 
           path "../../../../te/templates/node-template/name"; 
         } 
         description 
           "The reference to a TE node template."; 
       } 
       uses te-node-config-attributes; 
     } // te-node-config 
    
     grouping te-node-config-attributes { 
       description "Configuration node attributes in a TE topology."; 
       container te-node-attributes { 
         description "Containing node attributes in a TE topology."; 
         uses sch:schedules; 
         leaf admin-status { 
           type te-admin-status; 
           description 
             "The administrative state of the link."; 
         } 
         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 { 
             uses tet:tp-ref; 
             description  
               "Reference to source NTP."; 
           } 
           container to { 
             uses tet:tp-ref; 
             description  
 
  
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               "Reference to destination NTP."; 
           } 
           leaf is-allowed { 
             type boolean; 
             description 
               "true  - switching is allowed,  
                false - switching is disallowed."; 
           } 
         } 
         leaf domain-id { 
           type uint32; 
           description 
             "Identifies the domain that this node belongs. 
              This attribute is used to support inter-domain links."; 
           reference 
             "RFC5152: A Per-Domain Path Computation Method for 
              Establishing Inter-Domain Traffic Engineering (TE) 
              Label Switched Paths (LSPs). 
              RFC5392: OSPF Extensions in Support of Inter-Autonomous 
              System (AS) MPLS and GMPLS Traffic Engineering. 
              RFC5316: ISIS Extensions in Support of Inter-Autonomous 
              System (AS) MPLS and GMPLS Traffic Engineering."; 
         } 
         leaf-list flag { 
           type te-node-flag; 
           description "Node operational flags."; 
         } 
         leaf is-abstract { 
           type empty; 
           description  
             "Present if the node is abstract, not present if the node 
              is actual."; 
         } 
         leaf name { 
           type inet:domain-name; 
           description "Node name."; 
         } 
         leaf-list signaling-address { 
           type inet:ip-address; 
           description "Node signaling address."; 
         } 
         container underlay-topology { 
           if-feature te-topology-hierarchy; 
           description  
             "When an abstract node encapsulates a topology,  

 
 
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              the attributes in this container point to said 
   topology."; 
           uses te-topology-ref; 
         } 
       } 
     } // te-node-config-attributes 
        
     grouping te-node-state-derived { 
       description "Node state attributes in a TE topology."; 
       leaf oper-status { 
         type te-oper-status; 
         description 
           "The current operational state of the node."; 
       } 
       leaf is-multi-access-dr { 
         type empty; 
         description 
           "The presence of this attribute indicates that this TE node 
            is a pseudonode elected as a designated router."; 
         reference 
           "RFC3630: Traffic Engineering (TE) Extensions to OSPF 
            Version 2. 
            RFC1195: Use of OSI IS-IS for Routing in TCP/IP and Dual 
            Environments."; 
       } 
       uses information-source-attributes; 
     } // te-node-state-derived 
    
     grouping te-path-element { 
       description 
         "A group of attributes defining an element in a TE path 
         such as TE node, TE link, TE atomic resource or label."; 
       uses te-types:explicit-route-subobject; 
     } // te-path-element 
      
     grouping te-termination-point-augment { 
       description 
         "Augmentatin for TE termination point."; 
        
       container te { 
         presence "TE support.";       
         description  
           "Indicates TE support."; 
    
         leaf te-tp-id { 
           type te-tp-id; 
  
 
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           mandatory true; 
           description 
             "An identifier to uniquely identify a TE termination 
              point."; 
         } 
    
         container config { 
           description 
             "Configuration data."; 
           uses te-termination-point-config; 
         } // config 
         container state { 
           config false; 
           description 
             "Operational state data."; 
           uses te-termination-point-config; 
         } // state 
       } // te 
     } // te-termination-point-augment 
    
     grouping te-termination-point-config { 
       description  
         "TE termination point configuration grouping."; 
       uses sch:schedules; 
     } // te-termination-point-config 
    
     grouping te-topology-augment { 
       description 
         "Augmentatin for TE topology."; 
        
       container te { 
         presence "TE support."; 
         description  
           "Indicates TE support."; 
    
         leaf provider-id { 
           type te-global-id; 
           mandatory true; 
           description 
             "An identifier to uniquely identify a provider."; 
         } 
         leaf client-id { 
           type te-global-id; 
           mandatory true; 
           description 
             "An identifier to uniquely identify a client."; 
 
  
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         } 
         leaf te-topology-id { 
           type te-topology-id; 
           mandatory true; 
           description 
             "It is presumed that a datastore will contain many 
              topologies. To distinguish between topologies it is 
              vital to have UNIQUE topology identifiers."; 
         } 
    
         container config { 
           description 
             "Configuration data."; 
           uses te-topology-config; 
         } // config 
         container state { 
           config false; 
           description 
             "Operational state data."; 
           uses te-topology-config; 
         } // state 
    
         container templates { 
           description 
             "Configuration parameters for templates used for TE 
              topology."; 
    
           list node-template { 
             if-feature 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 template-attributes; 
             uses te-node-config-attributes; 
           } // node-template 
            
           list link-template { 
             if-feature template; 
             key "name"; 
             leaf name { 
 
  
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               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 template-attributes; 
             uses te-link-config-attributes; 
           } // link-template 
         } // templates 
       } // te 
     } // te-topology-augment 
    
     grouping te-topology-config { 
       description  
         "TE topology configuration grouping."; 
       uses sch:schedules; 
     } // te-topology-config 
    
     grouping te-topology-ref { 
       description 
         "References a TE topology."; 
       leaf provider-id-ref { 
         type leafref { 
           path "/nw:network/tet:te/tet:provider-id"; 
           require-instance false; 
         } 
         description 
           "A reference to a provider-id."; 
       } 
       leaf client-id-ref { 
         type leafref { 
           path "/nw:network/tet:te/tet:client-id"; 
           require-instance false; 
         } 
         description 
           "A reference to a client-id."; 
       } 
       leaf te-topology-id-ref { 
         type leafref { 
           path "/nw:network/tet:te/tet:te-topology-id"; 
           require-instance false; 
         } 
         description 
           "A reference to a te-topology-id."; 
 
 
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       } 
       leaf network-id-ref { 
         type leafref { 
           path "/nw:network/nw:network-id"; 
           require-instance false; 
         } 
         description 
           "A reference to a network-id in base ietf-network module."; 
       } 
     } // te-topology-ref 
    
     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."; 
       } 
     } // te-topology-type 
      
     grouping template-attributes { 
       description  
         "Common attributes for all templates."; 
    
       leaf priority { 
         type uint16; 
         description 
           "The preference value to resolve conflicts between different 
            templates. When two or more templates specify values for  
            one configuration attribute, the value from the template 
            with the highest priority is used."; 
       } 
       leaf reference-change-policy { 
         type enumeration { 
           enum no-action { 
             description 
               "When an attribute changes in this template, the  
                configuration node referring to this template does  
                not take any action."; 
           } 
           enum not-allowed { 
             description 
               "When any configuration object has a reference to this 
                template, changing this template is not allowed."; 
           } 
 
  
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           enum cascade { 
             description 
               "When an attribute changes in this template, the  
                configuration object referring to this template applies 
                the new attribute value to the corresponding  
                configuration."; 
           } 
         } 
         description 
           "This attribute specifies the action taken to a  
            configuration node that has a reference to this template."; 
       } 
     } // template-attributes 
    
     /* 
      * Configuration data nodes 
      */ 
     augment "/nw:network/nw:network-types" { 
       description 
         "Introduce new network type for TE topology."; 
       uses te-topology-type; 
     } 
    
     augment "/nw:network" { 
       when "nw:network-types/te-topology" { 
         description 
           "Augmentation parameters apply only for networks with 
            TE topology type."; 
       } 
       description 
         "Configuration parameters for TE topology."; 
       uses te-topology-augment; 
     } 
      
     augment "/nw:network/nw:node" { 
       when "../nw:network-types/te-topology" { 
         description 
           "Augmentation parameters apply only for networks with 
            TE topology type."; 
       } 
       description 
         "Configuration parameters for TE at node level."; 
       uses te-node-augment; 
     } 
    
     augment "/nw:network/nt:link" { 
 
  
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       when "../nw:network-types/te-topology" { 
         description 
           "Augmentation parameters apply only for networks with 
            TE topology type."; 
       } 
       description 
         "Configuration parameters for TE at link level"; 
       uses te-link-augment; 
     } 
    
     augment "/nw:network/nw:node/" 
            +"nt:termination-point" { 
       when "../../nw:network-types/te-topology" { 
         description 
           "Augmentation parameters apply only for networks with 
            TE topology type."; 
       } 
       description 
         "Configuration parameters for TE at termination point level"; 
       uses te-termination-point-augment; 
     } 
    
     /* 
      * Operational state data nodes 
      */ 
    
     /* 
      * Notifications 
      */ 
    
     notification te-node-event { 
       description "Notification event for TE node."; 
       leaf event-type { 
         type te-topology-event-type; 
         description "Event type."; 
       } 
       uses tet:node-ref; 
       uses te-topology-type; 
       uses tet:te-node-config-attributes; 
       uses tet:te-node-state-derived; 
     } 
      
     notification te-link-event { 
       description "Notification event for TE link."; 
       leaf event-type { 
         type te-topology-event-type; 
 
 
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         description "Event type"; 
       } 
       uses tet:link-ref; 
       uses te-topology-type; 
       uses tet:te-link-config-attributes; 
       uses tet:te-link-state-derived; 
     } 
    
     augment "/te-link-event/te-link-attributes/underlay" { 
       description "Add state attributes to te-link underlay."; 
       uses te-link-state-underlay-attributes; 
     } 
   } 
    
   <CODE ENDS> 
    
7. Security Considerations 

   The transport protocol used for retrieving/manipulating the TE 
   topology data MUST support authentication and SHOULD support 
   encryption. The data-model by itself does not create any security 
   implications. 
    
8. IANA Considerations 

   This document registers the following URIs in the IETF XML registry 
   [RFC3688]. Following the format in [RFC3688], the following 
   registration is requested to be made. 
    
   URI: urn:ietf:params:xml:ns:yang:ietf-te-topology  
   XML: N/A, the requested URI is an XML namespace. 
    
   This document registers a YANG module in the YANG Module Names 
   registry [RFC6020]. 
    
   name: ietf-te-topology  
   namespace: urn:ietf:params:xml:ns:yang:ietf-te-topology  
   prefix: tet 
    
       
9. References 

9.1. Normative References 

   [RFC2119]   Bradner, S., "Key words for use in RFCs to Indicate 
               Requirement Levels", BCP 14, RFC 2119, March 1997. 
 
 
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   [RFC3688]   Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688, 
               January 2004. 
    
   [RFC6020]   Bjorklund, M., "YANG - A Data Modeling Language for the 
               Network Configuration Protocol (NETCONF)", RFC 6020, 
               October 2010. 
    
   [RFC6991]   Schoenwaelder, J., "Common YANG Data Types", RFC 6991, 
               July 2013. 
    
   [RFC3945]   Mannie, E., "Generalized Multi-Protocol Label Switching  
               (GMPLS) Architecture", October 2004. 
    
   [YANG-NET-TOPO]   Clemm, A., "A Data Model for Network Topologies", 
               draft-ietf-i2rs-yang-network-topo (Work in Progress). 
    
   [YANG-PUSH] Clemm, A., "Subscribing to YANG datastore push updates",  
               draft-clemm-netconf-yang-push (Work in Progress). 
    
9.2. Informative References 

   [RFC2702]   Awduche, D., "Requirements for Traffic Engineering Over  
               MPLS", RFC 2702, September 1999. 
    

10. Acknowledgments 
    
   The authors would like to thank Lou Berger, Sue Hares, Mazen 
   Khaddam, Cyril Margaria and Zafar Ali for participating in design 
   discussions and providing valuable insights. 
 
Appendix A - Schedule Model 

   A.1 Tree Structure 

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

 
  
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   A.2 YANG Module 

   <CODE BEGINS> 

   module ietf-schedule { 
     yang-version 1; 
     namespace "urn:ietf:params:xml:ns:yang:ietf-schedule"; 
     // replace with IANA namespace when assigned 
      
     prefix "sch"; 
    
     import ietf-yang-types {  
       prefix "yang";  
     } 
    
     organization "TBD"; 
     contact "TBD"; 
     description  
       "The model allows time scheduling parameters to be specified."; 
      
     revision "2015-10-09" { 
       description "Initial revision"; 
       reference "TBD"; 
     } 
    
     /* 
      * Groupings 
      */ 
    
     grouping schedules { 
       description 
         "A list of schedules defining when a particular  
          configuration takes effect."; 
       container schedules { 
         description 
           "Container of a schedule list defining when a particular 
            configuration takes effect."; 
         list schedule { 
           key "schedule-id"; 
           description "A list of schedule elements."; 
            
           leaf schedule-id { 
             type uint32; 
             description "Identifies the schedule element."; 
 
  
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           } 
           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)?' 
                 + '(\d+S)?'; 
             } 
             description "Repeat interval in ISO 8601 format."; 
           } 
         } 
       } 
     } // schedules 
   } 
 
   <CODE ENDS> 
 
Contributors 

   Sergio Belotti 
   Alcatel Lucent 
   Email: sergio.belotti@alcatel-lucent.com 
    
   Dieter Beller 
   Alcatel Lucent 
   Email: dieter.beller@alcatel-lucent.com 
    
    
Authors' Addresses 

   Xufeng Liu 
   Ericsson 
   Email: xufeng.liu@ericsson.com 
    
   Igor Bryskin 
   ADVA Optical Networking 
 
  
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   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: hshah@ciena.com 
    
   Oscar Gonzalez De Dios 
   Telefonica 
   Email: oscar.gonzalezdedios@telefonica.com 

 
  
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