module ltp-path {
  namespace "urn:onf:params:xml:ns:yang:ltp-path";
  prefix ltp-path;

  import core-model {
    prefix core-model;
  }

  organization
   "ONF (Open Networking Foundation) Open Transport Working Group -
    Wireless Transport Project";
  contact 
    "WG Web: <https://www.opennetworking.org/technical-communities/areas/
              specification/1931-optical-transport>
     WG List:  <mailto:wireless-transport@login.opennetworking.org>
     WG Chair: Lyndon Ong
               <mailto:lyong@ciena.com>
     WG Chair: Giorgio Cazzaniga
               <mailto:giorgio.cazzaniga@sm-optics.com>
     Editor:   Martin Skorupski
               <mailto:martin.skorupski@highstreet-technologies.com>";
  description 
    "This module contains a collection of YANG definitions describing a 
     telecommunication network path.";
 
  revision 2017-05-26 {
    description "Initial version";
    reference "ltp-path, ONF core-model 1.2";
  }

  typedef layer-protocol-name-enumeration {
    type enumeration {
      enum ETH {
        value 1;
        description
          "Identifying the layer of Ethernet.";
      }
      enum PTP {
        value 2;
        description
          "Identifying the layer or the Precision Time Protocol.";
       }
    }

    description
      "The propagation of the layer protocol name.";
  }

  container ltp-path {
    description
      "Listing all the path-identifiers, used by RESTCONF interfaces to
       address an entry in the ltp-path-list.";

    leaf-list path-identifier {
      type leafref {
        path '/ltp-path/ltp-path-list/path-id';
      }
      description 
        "List of reference values for existing path entries.";
    }

    list ltp-path-list {

      key "path-id";

      description
        "A list of path found in the network.";

      leaf path-id {
        type string;
        description
          "A unique identifier of a path. It migth be beneficial to use the 
           format as defined in RFC 4122 
           (https://www.ietf.org/rfc/rfc4122.txt).";
      }

      leaf path-name {
        type string;
        description
          "The human readable name of a path. It should include start 
           and end point.";
      }

      leaf forwarding-direction {
        type core-model:forwarding-direction;
        description
          "Defines the directionality of the path.";
      }

      leaf layer-protocol-name {
        type layer-protocol-name-enumeration;
        description
          "Defines the layer of the path. Please see ONF CoreModel for 
           further details.";
      }

      list logical-termination-point-list {

        key "ltp-index";
        min-elements 2;

        description
          "An ordered list of logical-termination points, defining the path.";

        leaf ltp-index {
          type string;
          description
            "The index of the LTP with in the list. The LTP with the highest
             index is the end-point of the path. The LTP with the lowest
             index is the start-point of the path.";
        }

        leaf ltp-reference {
          type leafref {
            path '/core-model:network-element/core-model:ltp/core-model:uuid';
          }
          description
            "The reference value of a network-elements LTP.";
        }

        leaf physical-port-reference {
          type string;
          description
            "A text label for the unmodelled physical port associated with 
             the LTP. In many cases there is no associated physical port.";
        }
    
        leaf node-reference {
          type leafref {
            path '/core-model:network-element/core-model:uuid';
          }
          description
            "A reference value identifying a network-element.";
        }
      }
   }
  }
}