module ietf-te-topology {
  yang-version 1.1;
  namespace "urn:ietf:params:xml:ns:yang:ietf-te-topology";
  prefix tet;

  import ietf-yang-types {
    prefix yang;
    reference
      "RFC 6991: Common YANG Data Types";
  }
  import ietf-inet-types {
    prefix inet;
    reference
      "RFC 6991: Common YANG Data Types";
  }
  import ietf-te-types {
    prefix te-types;
    reference
      "RFC 8776: Common YANG Data Types for Traffic Engineering";
  }
  import ietf-network {
    prefix nw;
    reference
      "RFC 8345: A YANG Data Model for Network Topologies";
  }
  import ietf-network-topology {
    prefix nt;
    reference
      "RFC 8345: A YANG Data Model for Network Topologies";
  }

  organization
    "IETF Traffic Engineering Architecture and Signaling (TEAS)
     Working Group";
  contact
    "WG Web:   <https://datatracker.ietf.org/wg/teas/>
     WG List:  <mailto:teas@ietf.org>

     Editor:   Xufeng Liu
               <mailto:xufeng.liu.ietf@gmail.com>

     Editor:   Igor Bryskin
               <mailto:i_bryskin@yahoo.com>

     Editor:   Vishnu Pavan Beeram
               <mailto:vbeeram@juniper.net>

     Editor:   Tarek Saad
               <mailto:tsaad@juniper.net>

     Editor:   Himanshu Shah
               <mailto:hshah@ciena.com>

     Editor:   Oscar Gonzalez de Dios
               <mailto:oscar.gonzalezdedios@telefonica.com>";
  description
    "This YANG module defines a TE topology model for representing,
     retrieving, and manipulating technology-agnostic TE topologies.

     Copyright (c) 2020 IETF Trust and the persons identified as
     authors of the code.  All rights reserved.

     Redistribution and use in source and binary forms, with or
     without modification, is permitted pursuant to, and subject to
     the license terms contained in, the Simplified BSD License set
     forth in Section 4.c of the IETF Trust's Legal Provisions
     Relating to IETF Documents
     (https://trustee.ietf.org/license-info).

     This version of this YANG module is part of RFC 8795; see the
     RFC itself for full legal notices.";

  revision 2020-08-06 {
    description
      "Initial revision.";
    reference
      "RFC 8795: YANG Data Model for Traffic Engineering (TE)
       Topologies";
  }

  /*
   * Features
   */

  feature nsrlg {
    description
      "This feature indicates that the system supports NSRLGs
       (Non-Shared Risk Link Groups).";
  }

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

  feature template {
    description
      "This feature indicates that the system supports
       template configuration.";
  }

  /*
   * Typedefs
   */

  typedef geographic-coordinate-degree {
    type decimal64 {
      fraction-digits 8;
    }
    description
      "Decimal degree (DD) used to express latitude and longitude
       geographic coordinates.";
  }
  // geographic-coordinate-degree

  typedef te-info-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
          "IS-IS.";
      }
      enum bgp-ls {
        description
          "BGP-LS.";
        reference
          "RFC 7752: North-Bound Distribution of Link-State and
           Traffic Engineering (TE) Information Using BGP";
      }
      enum system-processed {
        description
          "System-processed entity.";
      }
      enum other {
        description
          "Other source.";
      }
    }
    description
      "Describes the type of source that has provided the
       related information, and the source's credibility.";
  }
  // te-info-source

  /*
   * Groupings
   */

  grouping connectivity-matrix-entry-path-attributes {
    description
      "Attributes of a connectivity matrix entry.";
    leaf is-allowed {
      type boolean;
      description
        "'true' - switching is allowed;
         'false' - switching is disallowed.";
    }
    container underlay {
      if-feature "te-topology-hierarchy";
      description
        "Attributes of the TE link underlay.";
      reference
        "RFC 4206: Label Switched Paths (LSP) Hierarchy with
         Generalized Multi-Protocol Label Switching (GMPLS)
         Traffic Engineering (TE)";
      uses te-link-underlay-attributes;
    }
    uses te-types:generic-path-constraints;
    uses te-types:generic-path-optimization;
    uses te-types:generic-path-properties;
  }
  // connectivity-matrix-entry-path-attributes

  grouping geolocation-container {
    description
      "Contains a GPS location.";
    container geolocation {
      config false;
      description
        "Contains a GPS location.";
      leaf altitude {
        type int64;
        units "millimeters";
        description
          "Distance above sea level.";
      }
      leaf latitude {
        type geographic-coordinate-degree {
          range "-90..90";
        }
        description
          "Relative position north or south on the Earth's surface.";
      }
      leaf longitude {
        type geographic-coordinate-degree {
          range "-180..180";
        }
        description
          "Angular distance east or west on the Earth's surface.";
      }
    }
    // geolocation
  }
  // geolocation-container

  grouping information-source-state-attributes {
    description
      "The attributes identifying the source that has provided the
       related information, and the source's credibility.";
    leaf credibility-preference {
      type uint16;
      description
        "The preference value for calculating the Traffic
         Engineering database credibility value used for
         tie-break selection between different information-source
         values.  A higher value is preferable.";
    }
    leaf logical-network-element {
      type string;
      description
        "When applicable, this is the name of a logical network
         element from which the information is learned.";
    }
    leaf network-instance {
      type string;
      description
        "When applicable, this is the name of a network instance
         from which the information is learned.";
    }
  }
  // information-source-state-attributes

  grouping information-source-per-link-attributes {
    description
      "Per-node container of the attributes identifying the source
       that has provided the related information, and the source's
       credibility.";
    leaf information-source {
      type te-info-source;
      config false;
      description
        "Indicates the type of information source.";
    }
    leaf information-source-instance {
      type string;
      config false;
      description
        "The name indicating the instance of the information
         source.";
    }
    container information-source-state {
      config false;
      description
        "Contains state attributes related to the information
         source.";
      uses information-source-state-attributes;
      container topology {
        description
          "When the information is processed by the system,
           the attributes in this container indicate which topology
           is used to generate the result information.";
        uses nt:link-ref;
      }
    }
  }
  // information-source-per-link-attributes

  grouping information-source-per-node-attributes {
    description
      "Per-node container of the attributes identifying the source
       that has provided the related information, and the source's
       credibility.";
    leaf information-source {
      type te-info-source;
      config false;
      description
        "Indicates the type of information source.";
    }
    leaf information-source-instance {
      type string;
      config false;
      description
        "The name indicating the instance of the information
         source.";
    }
    container information-source-state {
      config false;
      description
        "Contains state attributes related to the information
         source.";
      uses information-source-state-attributes;
      container topology {
        description
          "When the information is processed by the system,
           the attributes in this container indicate which topology
           is used to generate the result information.";
        uses nw:node-ref;
      }
    }
  }
  // information-source-per-node-attributes

  grouping interface-switching-capability-list {
    description
      "List of Interface Switching Capability Descriptors (ISCDs).";
    list interface-switching-capability {
      key "switching-capability encoding";
      description
        "List of ISCDs for this link.";
      reference
        "RFC 3471: Generalized Multi-Protocol Label Switching (GMPLS)
         Signaling Functional Description
         RFC 4203: 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 {
          base te-types:lsp-encoding-types;
        }
        description
          "Encoding supported by this interface.";
      }
      uses te-link-iscd-attributes;
    }
    // interface-switching-capability
  }
  // interface-switching-capability-list

  grouping statistics-per-link {
    description
      "Statistics attributes per TE link.";
    leaf discontinuity-time {
      type yang:date-and-time;
      description
        "The time of the most recent occasion at which any one or
         more of this interface's counters suffered a
         discontinuity.  If no such discontinuities have occurred
         since the last re-initialization of the local management
         subsystem, then this node contains the time the local
         management subsystem re-initialized itself.";
    }
    /* Administrative attributes */
    leaf disables {
      type yang:counter32;
      description
        "Number of times that a link was disabled.";
    }
    leaf enables {
      type yang:counter32;
      description
        "Number of times that a link was enabled.";
    }
    leaf maintenance-clears {
      type yang:counter32;
      description
        "Number of times that a link was taken out of maintenance.";
    }
    leaf maintenance-sets {
      type yang:counter32;
      description
        "Number of times that a link was put in maintenance.";
    }
    leaf modifies {
      type yang:counter32;
      description
        "Number of times that a link was modified.";
    }
    /* Operational attributes */
    leaf downs {
      type yang:counter32;
      description
        "Number of times that a link was set to an operational state
         of 'down'.";
    }
    leaf ups {
      type yang:counter32;
      description
        "Number of times that a link was set to an operational state
         of 'up'.";
    }
    /* Recovery attributes */
    leaf fault-clears {
      type yang:counter32;
      description
        "Number of times that a link experienced a fault-clear
         event.";
    }
    leaf fault-detects {
      type yang:counter32;
      description
        "Number of times that a link experienced fault detection.";
    }
    leaf protection-switches {
      type yang:counter32;
      description
        "Number of times that a link experienced protection
         switchover.";
    }
    leaf protection-reverts {
      type yang:counter32;
      description
        "Number of times that a link experienced protection
         reversion.";
    }
    leaf restoration-failures {
      type yang:counter32;
      description
        "Number of times that a link experienced restoration
         failure.";
    }
    leaf restoration-starts {
      type yang:counter32;
      description
        "Number of times that a link experienced restoration
         start.";
    }
    leaf restoration-successes {
      type yang:counter32;
      description
        "Number of times that a link experienced restoration
         success.";
    }
    leaf restoration-reversion-failures {
      type yang:counter32;
      description
        "Number of times that a link experienced restoration
         reversion failure.";
    }
    leaf restoration-reversion-starts {
      type yang:counter32;
      description
        "Number of times that a link experienced restoration
         reversion start.";
    }
    leaf restoration-reversion-successes {
      type yang:counter32;
      description
        "Number of times that a link experienced restoration
         reversion success.";
    }
  }
  // statistics-per-link

  grouping statistics-per-node {
    description
      "Statistics attributes per TE node.";
    leaf discontinuity-time {
      type yang:date-and-time;
      description
        "The time of the most recent occasion at which any one or
         more of this interface's counters suffered a
         discontinuity.  If no such discontinuities have occurred
         since the last re-initialization of the local management
         subsystem, then this node contains the time the local
         management subsystem re-initialized itself.";
    }
    container node {
      description
        "Contains statistics attributes at the TE node level.";
      leaf disables {
        type yang:counter32;
        description
          "Number of times that a node was disabled.";
      }
      leaf enables {
        type yang:counter32;
        description
          "Number of times that a node was enabled.";
      }
      leaf maintenance-sets {
        type yang:counter32;
        description
          "Number of times that a node was put in maintenance.";
      }
      leaf maintenance-clears {
        type yang:counter32;
        description
          "Number of times that a node was taken out of
           maintenance.";
      }
      leaf modifies {
        type yang:counter32;
        description
          "Number of times that a node was modified.";
      }
    }
    // node
    container connectivity-matrix-entry {
      description
        "Contains statistics attributes at the level of a
         connectivity matrix entry.";
      leaf creates {
        type yang:counter32;
        description
          "Number of times that a connectivity matrix entry was
           created.";
        reference
          "RFC 6241: Network Configuration Protocol (NETCONF),
                     Section 7.2, 'create' operation";
      }
      leaf deletes {
        type yang:counter32;
        description
          "Number of times that a connectivity matrix entry was
           deleted.";
        reference
          "RFC 6241: Network Configuration Protocol (NETCONF),
                     Section 7.2, 'delete' operation";
      }
      leaf disables {
        type yang:counter32;
        description
          "Number of times that a connectivity matrix entry was
           disabled.";
      }
      leaf enables {
        type yang:counter32;
        description
          "Number of times that a connectivity matrix entry was
           enabled.";
      }
      leaf modifies {
        type yang:counter32;
        description
          "Number of times that a connectivity matrix entry was
           modified.";
      }
    }
    // connectivity-matrix-entry
  }
  // statistics-per-node

  grouping statistics-per-ttp {
    description
      "Statistics attributes per TE TTP (Tunnel Termination Point).";
    leaf discontinuity-time {
      type yang:date-and-time;
      description
        "The time of the most recent occasion at which any one or
         more of this interface's counters suffered a
         discontinuity.  If no such discontinuities have occurred
         since the last re-initialization of the local management
         subsystem, then this node contains the time the local
         management subsystem re-initialized itself.";
    }
    container tunnel-termination-point {
      description
        "Contains statistics attributes at the TE TTP level.";
      /* Administrative attributes */
      leaf disables {
        type yang:counter32;
        description
          "Number of times that a TTP was disabled.";
      }
      leaf enables {
        type yang:counter32;
        description
          "Number of times that a TTP was enabled.";
      }
      leaf maintenance-clears {
        type yang:counter32;
        description
          "Number of times that a TTP was taken out of maintenance.";
      }
      leaf maintenance-sets {
        type yang:counter32;
        description
          "Number of times that a TTP was put in maintenance.";
      }
      leaf modifies {
        type yang:counter32;
        description
          "Number of times that a TTP was modified.";
      }
      /* Operational attributes */
      leaf downs {
        type yang:counter32;
        description
          "Number of times that a TTP was set to an operational state
           of 'down'.";
      }
      leaf ups {
        type yang:counter32;
        description
          "Number of times that a TTP was set to an operational state
           of 'up'.";
      }
      leaf in-service-clears {
        type yang:counter32;
        description
          "Number of times that a TTP was taken out of service
           (TE tunnel was released).";
      }
      leaf in-service-sets {
        type yang:counter32;
        description
          "Number of times that a TTP was put in service by a TE
           tunnel (TE tunnel was set up).";
      }
    }
    // tunnel-termination-point
    container local-link-connectivity {
      description
        "Contains statistics attributes at the TE LLCL (Local Link
         Connectivity List) level.";
      leaf creates {
        type yang:counter32;
        description
          "Number of times that an LLCL entry was created.";
        reference
          "RFC 6241: Network Configuration Protocol (NETCONF),
                     Section 7.2, 'create' operation";
      }
      leaf deletes {
        type yang:counter32;
        description
          "Number of times that an LLCL entry was deleted.";
        reference
          "RFC 6241: Network Configuration Protocol (NETCONF),
                     Section 7.2, 'delete' operation";
      }
      leaf disables {
        type yang:counter32;
        description
          "Number of times that an LLCL entry was disabled.";
      }
      leaf enables {
        type yang:counter32;
        description
          "Number of times that an LLCL entry was enabled.";
      }
      leaf modifies {
        type yang:counter32;
        description
          "Number of times that an LLCL entry was modified.";
      }
    }
    // local-link-connectivity
  }
  // statistics-per-ttp

  grouping te-link-augment {
    description
      "Augmentation for a TE link.";
    uses te-link-config;
    uses te-link-state-derived;
    container statistics {
      config false;
      description
        "Statistics data.";
      uses statistics-per-link;
    }
  }
  // te-link-augment

  grouping te-link-config {
    description
      "TE link configuration grouping.";
    choice bundle-stack-level {
      description
        "The TE link can be partitioned into bundled links or
         component links.";
      case bundle {
        container bundled-links {
          description
            "A set of bundled links.";
          reference
            "RFC 4201: Link Bundling in MPLS Traffic
             Engineering (TE)";
          list bundled-link {
            key "sequence";
            description
              "Specifies a bundled interface that is
               further partitioned.";
            leaf sequence {
              type uint32;
              description
                "Identifies the sequence in the bundle.";
            }
          }
        }
      }
      case component {
        container component-links {
          description
            "A set of component links.";
          list component-link {
            key "sequence";
            description
              "Specifies a component interface that is
               sufficient to unambiguously identify the
               appropriate resources.";
            leaf sequence {
              type uint32;
              description
                "Identifies the sequence in the bundle.";
            }
            leaf src-interface-ref {
              type string;
              description
                "Reference to a component link interface on the
                 source node.";
            }
            leaf des-interface-ref {
              type string;
              description
                "Reference to a component link interface on the
                 destination 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
      "Link configuration attributes in a TE topology.";
    container te-link-attributes {
      description
        "Link attributes in a TE topology.";
      leaf access-type {
        type te-types:te-link-access-type;
        description
          "Link access type, which can be point-to-point or
           multi-access.";
      }
      container external-domain {
        description
          "For an inter-domain link, specifies the attributes of
           the remote end of the link, to facilitate the signaling at
           the local end.";
        uses nw:network-ref;
        leaf remote-te-node-id {
          type te-types:te-node-id;
          description
            "Remote TE node identifier, used together with
             'remote-te-link-tp-id' to identify the remote Link
             Termination Point (LTP) in a different domain.";
        }
        leaf remote-te-link-tp-id {
          type te-types:te-tp-id;
          description
            "Remote TE LTP identifier, used together with
             'remote-te-node-id' to identify the remote LTP in a
             different domain.";
        }
      }
      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";
        description
          "Attributes of the TE link underlay.";
        reference
          "RFC 4206: Label Switched Paths (LSP) Hierarchy with
           Generalized Multi-Protocol Label Switching (GMPLS)
           Traffic Engineering (TE)";
        uses te-link-underlay-attributes;
      }
      leaf admin-status {
        type te-types:te-admin-status;
        description
          "The administrative state of the link.";
      }
      uses te-link-info-attributes;
    }
    // te-link-attributes
  }
  // te-link-config-attributes

  grouping te-link-info-attributes {
    description
      "Advertised TE information attributes.";
    leaf link-index {
      type uint64;
      description
        "The link identifier.  If OSPF is used, this object
         represents an ospfLsdbID.  If IS-IS is used, this object
         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 groups (defined
         in RFCs 3630 and 5305) and Extended Administrative Groups
         (defined in RFC 7308).";
      reference
        "RFC 3630: Traffic Engineering (TE) Extensions to OSPF
         Version 2
         RFC 5305: IS-IS Extensions for Traffic Engineering
         RFC 7308: Extended Administrative Groups in MPLS Traffic
         Engineering (MPLS-TE)";
    }
    uses interface-switching-capability-list;
    uses te-types:label-set-info;
    leaf link-protection-type {
      type identityref {
        base te-types:link-protection-type;
      }
      description
        "Link Protection Type desired for this link.";
      reference
        "RFC 4202: Routing Extensions in Support of
         Generalized Multi-Protocol Label Switching (GMPLS)";
    }
    container max-link-bandwidth {
      uses te-types:te-bandwidth;
      description
        "Maximum bandwidth that can be seen on this link in this
         direction.  Units are in bytes per second.";
      reference
        "RFC 3630: Traffic Engineering (TE) Extensions to OSPF
         Version 2
         RFC 5305: IS-IS Extensions for Traffic Engineering";
    }
    container max-resv-link-bandwidth {
      uses te-types:te-bandwidth;
      description
        "Maximum amount of bandwidth that can be reserved in this
         direction in this link.  Units are in bytes per second.";
      reference
        "RFC 3630: Traffic Engineering (TE) Extensions to OSPF
         Version 2
         RFC 5305: IS-IS Extensions for Traffic Engineering";
    }
    list unreserved-bandwidth {
      key "priority";
      max-elements 8;
      description
        "Unreserved bandwidth for priority levels 0-7.  Units are in
         bytes per second.";
      reference
        "RFC 3630: Traffic Engineering (TE) Extensions to OSPF
         Version 2
         RFC 5305: IS-IS Extensions for Traffic Engineering";
      leaf priority {
        type uint8 {
          range "0..7";
        }
        description
          "Priority.";
      }
      uses te-types:te-bandwidth;
    }
    leaf te-default-metric {
      type uint32;
      description
        "Traffic Engineering metric.";
      reference
        "RFC 3630: Traffic Engineering (TE) Extensions to OSPF
         Version 2
         RFC 5305: IS-IS Extensions for Traffic Engineering";
    }
    leaf te-delay-metric {
      type uint32;
      description
        "Traffic Engineering delay metric.";
      reference
        "RFC 7471: OSPF Traffic Engineering (TE) Metric Extensions";
    }
    leaf te-igp-metric {
      type uint32;
      description
        "IGP metric used for Traffic Engineering.";
      reference
        "RFC 3785: Use of Interior Gateway Protocol (IGP) Metric as a
         second MPLS Traffic Engineering (TE) Metric";
    }
    container te-srlgs {
      description
        "Contains a list of SRLGs.";
      leaf-list value {
        type te-types:srlg;
        description
          "SRLG value.";
        reference
          "RFC 4202: Routing Extensions in Support of
           Generalized Multi-Protocol Label Switching (GMPLS)";
      }
    }
    container te-nsrlgs {
      if-feature "nsrlg";
      description
        "Contains a list of NSRLGs (Non-Shared Risk Link Groups).
         When an abstract TE link is configured, this list specifies
         the request that underlay TE paths need to be mutually
         disjoint with other TE links in the same groups.";
      leaf-list id {
        type uint32;
        description
          "NSRLG ID, uniquely configured within a topology.";
        reference
          "RFC 4872: RSVP-TE Extensions in Support of End-to-End
           Generalized Multi-Protocol Label Switching (GMPLS)
           Recovery";
      }
    }
  }
  // te-link-info-attributes

  grouping te-link-iscd-attributes {
    description
      "TE link ISCD attributes.";
    reference
      "RFC 4203: OSPF Extensions in Support of Generalized
       Multi-Protocol Label Switching (GMPLS), Section 1.4";
    list max-lsp-bandwidth {
      key "priority";
      max-elements 8;
      description
        "Maximum Label Switched Path (LSP) bandwidth at
         priorities 0-7.";
      leaf priority {
        type uint8 {
          range "0..7";
        }
        description
          "Priority.";
      }
      uses te-types:te-bandwidth;
    }
  }
  // te-link-iscd-attributes

  grouping te-link-state-derived {
    description
      "Link state attributes in a TE topology.";
    leaf oper-status {
      type te-types:te-oper-status;
      config false;
      description
        "The current operational state of the link.";
    }
    leaf is-transitional {
      type empty;
      config false;
      description
        "Present if the link is transitional; used as an
         alternative approach in lieu of 'inter-layer-lock-id'
         for path computation in a TE topology covering multiple
         layers or multiple regions.";
      reference
        "RFC 5212: Requirements for GMPLS-Based Multi-Region and
         Multi-Layer Networks (MRN/MLN)
         RFC 6001: Generalized MPLS (GMPLS) Protocol Extensions
         for Multi-Layer and Multi-Region Networks (MLN/MRN)";
    }
    uses information-source-per-link-attributes;
    list information-source-entry {
      key "information-source information-source-instance";
      config false;
      description
        "A list of information sources learned, including the source
         that is used.";
      uses information-source-per-link-attributes;
      uses te-link-info-attributes;
    }
    container recovery {
      config false;
      description
        "Status of the recovery process.";
      leaf restoration-status {
        type te-types:te-recovery-status;
        description
          "Restoration status.";
      }
      leaf protection-status {
        type te-types:te-recovery-status;
        description
          "Protection status.";
      }
    }
    container underlay {
      if-feature "te-topology-hierarchy";
      config false;
      description
        "State attributes for the 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-derived

  grouping te-link-underlay-attributes {
    description
      "Attributes for the TE link underlay.";
    reference
      "RFC 4206: Label Switched Paths (LSP) Hierarchy with
       Generalized Multi-Protocol Label Switching (GMPLS)
       Traffic Engineering (TE)";
    leaf enabled {
      type boolean;
      description
        "'true' if the underlay is enabled.
         'false' if the underlay is disabled.";
    }
    container primary-path {
      description
        "The service path on the underlay topology that
         supports this link.";
      uses nw:network-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;
      }
    }
    // primary-path
    list 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 nw:network-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;
      }
    }
    // backup-path
    leaf protection-type {
      type identityref {
        base te-types:lsp-protection-type;
      }
      description
        "Underlay protection type desired for this link.";
    }
    container tunnel-termination-points {
      description
        "Underlay TTPs desired for this link.";
      leaf source {
        type binary;
        description
          "Source TTP identifier.";
      }
      leaf destination {
        type binary;
        description
          "Destination TTP identifier.";
      }
    }
    container tunnels {
      description
        "Underlay TE tunnels supporting this TE link.";
      leaf sharing {
        type boolean;
        default "true";
        description
          "'true' if the underlay tunnel can be shared with other
           TE links;
           'false' if the underlay tunnel is dedicated to this
           TE link.
           This leaf is the default option for all TE tunnels
           and may be overridden by the per-TE-tunnel value.";
      }
      list tunnel {
        key "tunnel-name";
        description
          "Zero, one, or more underlay TE tunnels that support this
           TE link.";
        leaf tunnel-name {
          type string;
          description
            "A tunnel name uniquely identifies an underlay TE tunnel,
             used together with the 'source-node' value for this
             link.";
          reference
            "RFC 3209: RSVP-TE: Extensions to RSVP for LSP Tunnels";
        }
        leaf sharing {
          type boolean;
          description
            "'true' if the underlay tunnel can be shared with other
             TE links;
             'false' if the underlay tunnel is dedicated to this
             TE link.";
        }
      }
      // tunnel
    }
    // tunnels
  }
  // te-link-underlay-attributes

  grouping te-node-augment {
    description
      "Augmentation for a TE node.";
    uses te-node-config;
    uses te-node-state-derived;
    container statistics {
      config false;
      description
        "Statistics data.";
      uses statistics-per-node;
    }
    list tunnel-termination-point {
      key "tunnel-tp-id";
      description
        "A termination point can terminate a tunnel.";
      leaf tunnel-tp-id {
        type binary;
        description
          "TTP identifier.";
      }
      uses te-node-tunnel-termination-point-config;
      leaf oper-status {
        type te-types:te-oper-status;
        config false;
        description
          "The current operational state of the TTP.";
      }
      uses geolocation-container;
      container statistics {
        config false;
        description
          "Statistics data.";
        uses statistics-per-ttp;
      }
      // Relationship to other TTPs
      list supporting-tunnel-termination-point {
        key "node-ref tunnel-tp-ref";
        description
          "Identifies the TTPs on which this TTP depends.";
        leaf node-ref {
          type inet:uri;
          description
            "This leaf identifies the node in which the supporting
             TTP is present.
             This node is either the supporting node or a node in
             an underlay topology.";
        }
        leaf tunnel-tp-ref {
          type binary;
          description
            "Reference to a TTP that is in either the supporting node
             or a node in an underlay topology.";
        }
      }
      // supporting-tunnel-termination-point
    }
    // tunnel-termination-point
  }
  // 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
        "Contains node attributes in a TE topology.";
      leaf admin-status {
        type te-types:te-admin-status;
        description
          "The administrative state of the link.";
      }
      uses te-node-connectivity-matrices;
      uses te-node-info-attributes;
    }
  }
  // te-node-config-attributes

  grouping te-node-config-attributes-template {
    description
      "Configuration node attributes for a template in a TE
       topology.";
    container te-node-attributes {
      description
        "Contains node attributes in a TE topology.";
      leaf admin-status {
        type te-types:te-admin-status;
        description
          "The administrative state of the link.";
      }
      uses te-node-info-attributes;
    }
  }
  // te-node-config-attributes-template

  grouping te-node-connectivity-matrices {
    description
      "Connectivity matrix on a TE node.";
    container connectivity-matrices {
      description
        "Contains a connectivity matrix on a TE node.";
      leaf number-of-entries {
        type uint16;
        description
          "The number of connectivity matrix entries.
           If this number is specified in the configuration request,
           the number is the requested number of entries, which may
           not all be listed in the list;
           if this number is reported in the state data,
           the number is the current number of operational entries.";
      }
      uses te-types:label-set-info;
      uses connectivity-matrix-entry-path-attributes;
      list connectivity-matrix {
        key "id";
        description
          "Represents a node's switching limitations, i.e.,
           limitations in the interconnecting network TE links
           across the node.";
        reference
          "RFC 7579: General Network Element Constraint Encoding
           for GMPLS-Controlled Networks";
        leaf id {
          type uint32;
          description
            "Identifies the connectivity matrix entry.";
        }
      }
      // connectivity-matrix
    }
    // connectivity-matrices
  }
  // te-node-connectivity-matrices

  grouping te-node-connectivity-matrix-attributes {
    description
      "Termination point references of a connectivity matrix entry.";
    container from {
      description
        "Reference to a source LTP.";
      leaf tp-ref {
        type leafref {
          path "../../../../../../nt:termination-point/nt:tp-id";
        }
        description
          "Relative reference to a termination point.";
      }
      uses te-types:label-set-info;
    }
    container to {
      description
        "Reference to a destination LTP.";
      leaf tp-ref {
        type leafref {
          path "../../../../../../nt:termination-point/nt:tp-id";
        }
        description
          "Relative reference to a termination point.";
      }
      uses te-types:label-set-info;
    }
    uses connectivity-matrix-entry-path-attributes;
  }
  // te-node-connectivity-matrix-attributes

  grouping te-node-info-attributes {
    description
      "Advertised TE information attributes.";
    leaf domain-id {
      type uint32;
      description
        "Identifies the domain to which this node belongs.
         This attribute is used to support inter-domain links.";
      reference
        "RFC 5152: A Per-Domain Path Computation Method for
         Establishing Inter-Domain Traffic Engineering (TE)
         Label Switched Paths (LSPs)
         RFC 5316: ISIS Extensions in Support of Inter-Autonomous
         System (AS) MPLS and GMPLS Traffic Engineering
         RFC 5392: OSPF Extensions in Support of Inter-Autonomous
         System (AS) MPLS and GMPLS Traffic Engineering";
    }
    leaf is-abstract {
      type empty;
      description
        "Present if the node is abstract; not present if the node
         is actual.";
    }
    leaf name {
      type string;
      description
        "Node name.";
    }
    leaf-list signaling-address {
      type inet:ip-address;
      description
        "The node's signaling address.";
    }
    container underlay-topology {
      if-feature "te-topology-hierarchy";
      description
        "When an abstract node encapsulates a topology, the
         attributes in this container point to said topology.";
      uses nw:network-ref;
    }
  }
  // te-node-info-attributes

  grouping te-node-state-derived {
    description
      "Node state attributes in a TE topology.";
    leaf oper-status {
      type te-types:te-oper-status;
      config false;
      description
        "The current operational state of the node.";
    }
    uses geolocation-container;
    leaf is-multi-access-dr {
      type empty;
      config false;
      description
        "The presence of this attribute indicates that this TE node
         is a pseudonode elected as a designated router.";
      reference
        "RFC 1195: Use of OSI IS-IS for Routing in TCP/IP and Dual
         Environments
         RFC 3630: Traffic Engineering (TE) Extensions to OSPF
         Version 2";
    }
    uses information-source-per-node-attributes;
    list information-source-entry {
      key "information-source information-source-instance";
      config false;
      description
        "A list of information sources learned, including the source
         that is used.";
      uses information-source-per-node-attributes;
      uses te-node-connectivity-matrices;
      uses te-node-info-attributes;
    }
  }
  // te-node-state-derived

  grouping te-node-tunnel-termination-point-config {
    description
      "Termination capability of a TTP on a TE node.";
    uses te-node-tunnel-termination-point-config-attributes;
    container local-link-connectivities {
      description
        "Contains an LLCL for a TTP on a TE node.";
      leaf number-of-entries {
        type uint16;
        description
          "The number of LLCL entries.
           If this number is specified in the configuration request,
           the number is the requested number of entries, which may
           not all be listed in the list;
           if this number is reported in the state data,
           the number is the current number of operational entries.";
      }
      uses te-types:label-set-info;
      uses connectivity-matrix-entry-path-attributes;
    }
  }
  // te-node-tunnel-termination-point-config

  grouping te-node-tunnel-termination-point-config-attributes {
    description
      "Configuration attributes of a TTP on a TE node.";
    leaf admin-status {
      type te-types:te-admin-status;
      description
        "The administrative state of the TTP.";
    }
    leaf name {
      type string;
      description
        "A descriptive name for the TTP.";
    }
    leaf switching-capability {
      type identityref {
        base te-types:switching-capabilities;
      }
      description
        "Switching capability for this interface.";
    }
    leaf encoding {
      type identityref {
        base te-types:lsp-encoding-types;
      }
      description
        "Encoding supported by this interface.";
    }
    leaf-list inter-layer-lock-id {
      type uint32;
      description
        "Inter-layer lock ID, used for path computation in a TE
         topology covering multiple layers or multiple regions.";
      reference
        "RFC 5212: Requirements for GMPLS-Based Multi-Region and
         Multi-Layer Networks (MRN/MLN)
         RFC 6001: Generalized MPLS (GMPLS) Protocol Extensions
         for Multi-Layer and Multi-Region Networks (MLN/MRN)";
    }
    leaf protection-type {
      type identityref {
        base te-types:lsp-protection-type;
      }
      description
        "The protection type that this TTP is capable of.";
    }
    container client-layer-adaptation {
      description
        "Contains capability information to support a client-layer
         adaptation in a multi-layer topology.";
      list switching-capability {
        key "switching-capability encoding";
        description
          "List of supported switching capabilities.";
        reference
          "RFC 4202: Routing Extensions in Support of
           Generalized Multi-Protocol Label Switching (GMPLS)
           RFC 6001: Generalized MPLS (GMPLS) Protocol Extensions
           for Multi-Layer and Multi-Region Networks (MLN/MRN)";
        leaf switching-capability {
          type identityref {
            base te-types:switching-capabilities;
          }
          description
            "Switching capability for the client-layer adaptation.";
        }
        leaf encoding {
          type identityref {
            base te-types:lsp-encoding-types;
          }
          description
            "Encoding supported by the client-layer adaptation.";
        }
        uses te-types:te-bandwidth;
      }
    }
  }
  // te-node-tunnel-termination-point-config-attributes

  grouping te-node-tunnel-termination-point-llc-list {
    description
      "LLCL of a TTP on a TE node.";
    list local-link-connectivity {
      key "link-tp-ref";
      description
        "The termination capabilities between the TTP and the LTP.
         This capability information can be used to compute
         the tunnel path.
         The Interface Adjustment Capability Descriptors (IACDs)
         (defined in RFC 6001) on each LTP can be derived from
         this list.";
      reference
        "RFC 6001: Generalized MPLS (GMPLS) Protocol Extensions
         for Multi-Layer and Multi-Region Networks (MLN/MRN)";
      leaf link-tp-ref {
        type leafref {
          path "../../../../../nt:termination-point/nt:tp-id";
        }
        description
          "LTP.";
      }
      uses te-types:label-set-info;
      uses connectivity-matrix-entry-path-attributes;
    }
  }
  // te-node-tunnel-termination-point-llc-list

  grouping te-path-element {
    description
      "A group of attributes defining an element in a TE path,
       such as a TE node, TE link, TE atomic resource, or label.";
    uses te-types:explicit-route-hop;
  }
  // te-path-element

  grouping te-termination-point-augment {
    description
      "Augmentation for a TE termination point.";
    leaf te-tp-id {
      type te-types:te-tp-id;
      description
        "An identifier that uniquely identifies a TE termination
         point.";
    }
    container te {
      must '../te-tp-id';
      presence "TE support";
      description
        "Indicates TE support.";
      uses te-termination-point-config;
      leaf oper-status {
        type te-types:te-oper-status;
        config false;
        description
          "The current operational state of the LTP.";
      }
      uses geolocation-container;
    }
  }
  // te-termination-point-augment

  grouping te-termination-point-config {
    description
      "TE termination point configuration grouping.";
    leaf admin-status {
      type te-types:te-admin-status;
      description
        "The administrative state of the LTP.";
    }
    leaf name {
      type string;
      description
        "A descriptive name for the LTP.";
    }
    uses interface-switching-capability-list;
    leaf inter-domain-plug-id {
      type binary;
      description
        "A network-wide unique number that identifies on the
         network a connection that supports a given inter-domain
         TE link.  This is a more flexible alternative to specifying
         'remote-te-node-id' and 'remote-te-link-tp-id' on a TE link
         when the provider either does not know 'remote-te-node-id'
         and 'remote-te-link-tp-id' or needs to give the client the
         flexibility to mix and match multiple topologies.";
    }
    leaf-list inter-layer-lock-id {
      type uint32;
      description
        "Inter-layer lock ID, used for path computation in a TE
         topology covering multiple layers or multiple regions.";
      reference
        "RFC 5212: Requirements for GMPLS-Based Multi-Region and
         Multi-Layer Networks (MRN/MLN)
         RFC 6001: Generalized MPLS (GMPLS) Protocol Extensions
         for Multi-Layer and Multi-Region Networks (MLN/MRN)";
    }
  }
  // te-termination-point-config

  grouping te-topologies-augment {
    description
      "Augmentation for TE topologies.";
    container te {
      presence "TE support";
      description
        "Indicates TE support.";
      container templates {
        description
          "Configuration parameters for templates used for a TE
           topology.";
        list node-template {
          if-feature "template";
          key "name";
          leaf name {
            type te-types: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-template;
        }
        // node-template
        list link-template {
          if-feature "template";
          key "name";
          leaf name {
            type te-types: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-topologies-augment

  grouping te-topology-augment {
    description
      "Augmentation for a TE topology.";
    uses te-types:te-topology-identifier;
    container te {
      must '../te-topology-identifier/provider-id'
         + ' and ../te-topology-identifier/client-id'
         + ' and ../te-topology-identifier/topology-id';
      presence "TE support";
      description
        "Indicates TE support.";
      uses te-topology-config;
      uses geolocation-container;
    }
  }
  // te-topology-augment

  grouping te-topology-config {
    description
      "TE topology configuration grouping.";
    leaf name {
      type string;
      description
        "Name of the TE topology.  This attribute is optional and can
         be specified by the operator to describe the TE topology,
         which can be useful when 'network-id' (RFC 8345) is not
         descriptive and not modifiable because of being generated
         by the system.";
      reference
        "RFC 8345: A YANG Data Model for Network Topologies";
    }
    leaf preference {
      type uint8 {
        range "1..255";
      }
      description
        "Specifies a preference for this topology.  A lower number
         indicates a higher preference.";
    }
    leaf optimization-criterion {
      type identityref {
        base te-types:objective-function-type;
      }
      description
        "Optimization criterion applied to this topology.";
      reference
        "RFC 3272: Overview and Principles of Internet Traffic
         Engineering";
    }
    list nsrlg {
      if-feature "nsrlg";
      key "id";
      description
        "List of NSRLGs (Non-Shared Risk Link Groups).";
      reference
        "RFC 4872: RSVP-TE Extensions in Support of End-to-End
         Generalized Multi-Protocol Label Switching (GMPLS)
         Recovery";
      leaf id {
        type uint32;
        description
          "Identifies the NSRLG entry.";
      }
      leaf disjointness {
        type te-types:te-path-disjointness;
        description
          "The type of resource disjointness.";
      }
    }
    // nsrlg
  }
  // te-topology-config

  grouping template-attributes {
    description
      "Common attributes for all templates.";
    leaf priority {
      type uint16;
      description
        "The preference value for resolving 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.
         A lower number indicates a higher priority.  The highest
         priority is 0.";
    }
    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.";
        }
        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 for a
         configuration node that has a reference to this template.";
    }
  }
  // template-attributes

  /*
   * Data nodes
   */

  augment "/nw:networks/nw:network/nw:network-types" {
    description
      "Introduces a new network type for a TE topology.";
    container te-topology {
      presence "Indicates a TE topology";
      description
        "Its presence identifies the TE topology type.";
    }
  }

  augment "/nw:networks" {
    description
      "Augmentation parameters for TE topologies.";
    uses te-topologies-augment;
  }

  augment "/nw:networks/nw:network" {
    when 'nw:network-types/tet:te-topology' {
      description
        "Augmentation parameters apply only for networks with a
         TE topology type.";
    }
    description
      "Configuration parameters for a TE topology.";
    uses te-topology-augment;
  }

  augment "/nw:networks/nw:network/nw:node" {
    when '../nw:network-types/tet:te-topology' {
      description
        "Augmentation parameters apply only for networks with a
         TE topology type.";
    }
    description
      "Configuration parameters for TE at the node level.";
    leaf te-node-id {
      type te-types:te-node-id;
      description
        "The identifier of a node in the TE topology.
         A node is specific to a topology to which it belongs.";
    }
    container te {
      must '../te-node-id' {
        description
          "'te-node-id' is mandatory.";
      }
      must 'count(../nw:supporting-node)<=1' {
        description
          "For a node in a TE topology, there cannot be more
           than one supporting node.  If multiple nodes are
           abstracted, the 'underlay-topology' field is used.";
      }
      presence "TE support";
      description
        "Indicates TE support.";
      uses te-node-augment;
    }
  }

  augment "/nw:networks/nw:network/nt:link" {
    when '../nw:network-types/tet:te-topology' {
      description
        "Augmentation parameters apply only for networks with a
         TE topology type.";
    }
    description
      "Configuration parameters for TE at the link level.";
    container te {
      must 'count(../nt:supporting-link)<=1' {
        description
          "For a link in a TE topology, there cannot be more
           than one supporting link.  If one or more link paths are
           abstracted, the underlay is used.";
      }
      presence "TE support";
      description
        "Indicates TE support.";
      uses te-link-augment;
    }
  }

  augment "/nw:networks/nw:network/nw:node/"
        + "nt:termination-point" {
    when '../../nw:network-types/tet:te-topology' {
      description
        "Augmentation parameters apply only for networks with a
         TE topology type.";
    }
    description
      "Configuration parameters for TE at the termination point
       level.";
    uses te-termination-point-augment;
  }

  augment "/nw:networks/nw:network/nt:link/te/bundle-stack-level/"
        + "bundle/bundled-links/bundled-link" {
    when '../../../../nw:network-types/tet:te-topology' {
      description
        "Augmentation parameters apply only for networks with a
         TE topology type.";
    }
    description
      "Augmentation for a TE bundled link.";
    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 source 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.";
    }
  }

  augment "/nw:networks/nw:network/nw:node/te/"
        + "information-source-entry/connectivity-matrices/"
        + "connectivity-matrix" {
    when '../../../../../nw:network-types/tet:te-topology' {
      description
        "Augmentation parameters apply only for networks with a
         TE topology type.";
    }
    description
      "Augmentation for the TE node connectivity matrix.";
    uses te-node-connectivity-matrix-attributes;
  }

  augment "/nw:networks/nw:network/nw:node/te/te-node-attributes/"
        + "connectivity-matrices/connectivity-matrix" {
    when '../../../../../nw:network-types/tet:te-topology' {
      description
        "Augmentation parameters apply only for networks with a
         TE topology type.";
    }
    description
      "Augmentation for the TE node connectivity matrix.";
    uses te-node-connectivity-matrix-attributes;
  }

  augment "/nw:networks/nw:network/nw:node/te/"
        + "tunnel-termination-point/local-link-connectivities" {
    when '../../../../nw:network-types/tet:te-topology' {
      description
        "Augmentation parameters apply only for networks with a
         TE topology type.";
    }
    description
      "Augmentation for TE node TTP LLCs (Local Link
       Connectivities).";
    uses te-node-tunnel-termination-point-llc-list;
  }
}