module ietf-bfd-mpls {

    yang-version 1.1;

    namespace
      "urn:ietf:params:xml:ns:yang:ietf-bfd-mpls";

    prefix bfd-mpls;

    import ietf-bfd-types {
      prefix bfd-types;
      reference
        "RFC 9127: YANG Data Model for Bidirectional Forwarding
        Detection (BFD)";


    }
    import ietf-bfd {
      prefix bfd;
      reference
        "RFC 9127: YANG Data Model for Bidirectional Forwarding
        Detection (BFD)";


    }
    import ietf-inet-types {
      prefix inet;
      reference
        "RFC 6991: Common YANG Data Types";


    }
    import ietf-routing {
      prefix rt;
      reference
        "RFC 8349: A YANG Data Model for Routing Management
        (NMDA Version)";


    }

    organization "IETF BFD Working Group";

    contact
      "WG Web:   <https://datatracker.ietf.org/wg/bfd/>
     WG List:  <mailto:rtg-bfd@ietf.org>

     Editor:   Reshad Rahman
               <mailto:reshad@yahoo.com>

     Editor:   Lianshu Zheng
               <mailto:veronique_cheng@hotmail.com>

     Editor:   Mahesh Jethanandani
               <mailto:mjethanandani@gmail.com>";

    description
      "This module contains the YANG definition for BFD parameters for
     MPLS LSPs as per RFC 5884.

     Copyright (c) 2021 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 9127; see the
     RFC itself for full legal notices.";

    reference
      "RFC 5884: Bidirectional Forwarding Detection (BFD)
      for MPLS Label Switched Paths (LSPs)
       RFC 9127: YANG Data Model for Bidirectional Forwarding
      Detection (BFD)";


    revision "2021-10-21" {
      description "Initial revision.";
      reference
        "RFC 9127: YANG Data Model for Bidirectional Forwarding
        Detection (BFD)";

    }


    identity encap-gach {
      base bfd-types:encap-type;
      description
        "BFD with G-ACh encapsulation as per RFC 5586.";
      reference
        "RFC 5586: MPLS Generic Associated Channel";

    }

    identity encap-ip-gach {
      base bfd-types:encap-type;
      description
        "BFD with IP and G-ACh encapsulation as per RFC 5586.";
    }

    grouping encap-cfg {
      description
        "Configuration for BFD encapsulation.";
      leaf encap {
        type identityref {
          base bfd-types:encap-type;
        }
        default "bfd-types:encap-ip";
        description "BFD encapsulation.";
      }
    }  // grouping encap-cfg

    grouping mpls-dest-address {
      description
        "Destination address as per RFC 5884.";
      reference
        "RFC 5884: Bidirectional Forwarding Detection (BFD)
        for MPLS Label Switched Paths (LSPs)";

      leaf mpls-dest-address {
        type inet:ip-address;
        config false;
        description
          "Destination address as per RFC 5884.
         Needed if IP encapsulation is used.";
      }
    }  // grouping mpls-dest-address

    augment /rt:routing/rt:control-plane-protocols/rt:control-plane-protocol/bfd:bfd {
      description
        "BFD augmentation for MPLS.";
      container mpls {
        description
          "BFD MPLS top-level container.";
        uses bfd-types:session-statistics-summary;

        container egress {
          description
            "Egress configuration.";
          uses bfd-types:client-cfg-parms;

          uses bfd-types:auth-parms;
        }  // container egress

        container session-groups {
          description
            "BFD-over-MPLS session groups.";
          list session-group {
            key "mpls-fec";
            description
              "Group of BFD MPLS sessions (for ECMP).  A group of
             sessions is for one FEC.  Each session has a different
             field in the UDP/IP header for ECMP.";
            leaf mpls-fec {
              type inet:ip-prefix;
              description "MPLS FEC.";
            }

            uses bfd-types:common-cfg-parms;

            list sessions {
              config false;
              description
                "The BFD sessions for an MPLS FEC.  The local
               discriminator is unique for each session in the
               group.";
              uses bfd-types:all-session;

              uses bfd-mpls:mpls-dest-address;
            }  // list sessions
          }  // list session-group
        }  // container session-groups
      }  // container mpls
    }

    notification mpls-notification {
      description
        "Notification for BFD-over-MPLS FEC session state change.
       An implementation may rate-limit notifications, e.g., when a
       session is continuously changing state.";
      uses bfd-types:notification-parms;

      leaf mpls-dest-address {
        type inet:ip-address;
        description
          "Destination address as per RFC 5884.
         Needed if IP encapsulation is used.";
      }
    }  // notification mpls-notification
  }  // module ietf-bfd-mpls