module ietf-pseudowires {

    yang-version 1;

    namespace
      "urn:ietf:params:xml:ns:yang:ietf-pseudowires";

    prefix pw;

    import ietf-inet-types {
      prefix inet;
    }
    import ietf-routing-types {
      prefix rt-types;
    }

    organization "ietf";

    contact "ietf";

    description "Pseudowire YANG model";

    revision "2018-10-22" {
      description
        "Second revision   - Added group-id and attachment identifiers ";
      reference
        "";

    }

    revision "2017-06-26" {
      description
        "Initial revision   - Created a new model for pseudowires, which used     to be defined within the L2VPN model ";
      reference
        "";

    }


    typedef pseudowire-ref {
      type leafref {
        path "/pw:pseudowires/pw:pseudowire/pw:name";
      }
      description
        "A type that is a reference to a pseudowire";
    }

    typedef pw-template-ref {
      type leafref {
        path "/pw:pseudowires/pw:pw-templates/pw:pw-template/pw:name";
      }
      description
        "A type that is a reference to a pw-template";
    }

    typedef cw-negotiation-type {
      type enumeration {
        enum "non-preferred" {
          value 0;
          description
            "No preference for control-word";
        }
        enum "preferred" {
          value 1;
          description
            "Prefer to have control-word negotiation";
        }
      }
      description
        "control-word negotiation preference type";
    }

    typedef pseudowire-status-type {
      type bits {
        bit pseudowire-forwarding {
          position 0;
          description
            "Pseudowire is forwarding";
        }
        bit pseudowire-not-forwarding {
          position 1;
          description
            "Pseudowire is not forwarding";
        }
        bit
          local-attachment-circuit-receive-fault {
          position 2;
          description
            "Local attachment circuit (ingress) receive fault";
        }
        bit
          local-attachment-circuit-transmit-fault {
          position 3;
          description
            "Local attachment circuit (egress) transmit fault";
        }
        bit
          local-PSN-facing-PW-receive-fault {
          position 4;
          description
            "Local PSN-facing PW (ingress) receive fault";
        }
        bit
          local-PSN-facing-PW-transmit-fault {
          position 5;
          description
            "Local PSN-facing PW (egress) transmit fault";
        }
        bit
          PW-preferential-forwarding-status {
          position 6;
          description
            "Pseudowire preferential forwarding status";
        }
        bit PW-request-switchover-status {
          position 7;
          description
            "Pseudowire request switchover status";
        }
      }
      description
        "Pseudowire status type, as registered in the IANA Pseudowire Status Code Registry";
    }

    container pseudowires {
      description
        "Configuration management of pseudowires";
      list pseudowire {
        key "name";
        description "A pseudowire";
        leaf name {
          type string;
          description "pseudowire name";
        }

        leaf state {
          type pseudowire-status-type;
          config false;
          description
            "pseudowire operation status";
          reference
            "RFC 4446 and IANA Pseudowire Status Codes Registery";

        }

        leaf template {
          type pw-template-ref;
          description "pseudowire template";
        }

        leaf mtu {
          type uint16;
          description "PW MTU";
        }

        leaf mac-withdraw {
          type boolean;
          default "false";
          description
            "Enable (true) or disable (false) MAC withdraw";
        }

        leaf pw-loadbalance {
          type enumeration {
            enum "disabled" {
              value 0;
              description
                "load-balancing disabled";
            }
            enum "fat-pw" {
              value 1;
              description
                "load-balance using FAT label below PW label";
            }
            enum "entropy" {
              value 2;
              description
                "load-balance using ELI/EL above PW label";
            }
          }
          description "PW load-balancing";
        }

        leaf ms-pw-member {
          type boolean;
          default "false";
          description
            "Enable (true) or disable (false) not a member of MS-PW";
        }

        leaf cw-negotiation {
          type cw-negotiation-type;
          description "cw-negotiation";
        }

        leaf tunnel-policy {
          type string;
          description "tunnel policy name";
        }

        choice pw-type {
          description
            "A choice of pseudowire type";
          case configured-pw {
            leaf peer-ip {
              type inet:ip-address;
              description "peer IP address";
            }

            leaf pw-id {
              type uint32;
              description "pseudowire id";
            }

            leaf group-id {
              type uint32;
              description "group id";
            }

            leaf icb {
              type boolean;
              description
                "inter-chassis backup";
            }

            leaf transmit-label {
              type rt-types:mpls-label;
              description "transmit lable";
            }

            leaf receive-label {
              type rt-types:mpls-label;
              description "receive label";
            }

            leaf generalized {
              type boolean;
              description
                "generalized pseudowire id FEC element";
            }

            leaf agi {
              type string;
              description
                "attachment group identifier";
            }

            leaf saii {
              type string;
              description
                "source attachment individual identifier";
            }

            leaf taii {
              type string;
              description
                "target attachment individual identifier";
            }
          }  // case configured-pw
          leaf remote-pe-id {
            type inet:ip-address;
            description "remote pe id";
          }
          leaf remote-ve-id {
            type uint16;
            description "remote ve id";
          }
        }  // choice pw-type
      }  // list pseudowire

      container pw-templates {
        description "pw-templates";
        list pw-template {
          key "name";
          description "pw-template";
          leaf name {
            type string;
            description "name";
          }

          leaf mtu {
            type uint16;
            description "pseudowire mtu";
          }

          leaf cw-negotiation {
            type cw-negotiation-type;
            default "preferred";
            description
              "control-word negotiation preference";
          }

          leaf tunnel-policy {
            type string;
            description "tunnel policy name";
          }
        }  // list pw-template
      }  // container pw-templates
    }  // container pseudowires
  }  // module ietf-pseudowires