module ietf-connection-oriented-oam {

    yang-version 1.1;

    namespace
      "urn:ietf:params:xml:ns:yang:ietf-connection-oriented-oam";

    prefix co-oam;

    import ietf-yang-types {
      prefix yang;
    }
    import ietf-inet-types {
      prefix inet;
    }
    import ietf-interfaces {
      prefix if;
    }

    organization "IETF LIME Working Group";

    contact
      "WG Web:    http://tools.ietf.org/wg/lime
     WG List:   mailto:lime@ietf.org
     Editor:    Deepak Kumar dekumar@cisco.com
     Editor:    Qin Wu bill.wu@huawei.com
     Editor:    Zitao Wang wangzitao@huawei.com";

    description
      "This YANG module defines the generic configuration,
     statistics and rpc for connection oriented OAM
     to be used within IETF in a protocol independent manner.
     Functional level abstraction is independent
     with YANG modeling. It is assumed that each protocol
     maps corresponding abstracts to its native format.
     Each protocol may extend the YANG model defined
     here to include protocol specific extensions";

    revision "2018-02-07" {
      description
        "Initial revision. - 12 version";
      reference
        "draft-ietf-lime-yang-oam-model";

    }


    feature connectivity-verification {
      description
        "This feature indicates that the server supports
       executing connectivity verification OAM command and
       returning a response. Servers that do not advertise
       this feature will not support executing
       connectivity verification command or rpc model for
       connectivity verification command.";
    }

    feature continuity-check {
      description
        "This feature indicates that the server supports
       executing continuity check OAM command and
       returning a response. Servers that do not advertise
       this feature will not support executing
       continuity check command or rpc model for
       continuity check command.";
    }

    feature traceroute {
      description
        "This feature indicates that the server supports
       executing traceroute OAM command and
       returning a response. Servers that do not advertise
       this feature will not support executing
       traceroute command or rpc model for
       traceroute command.";
    }

    feature mip {
      description
        "This feature indicates that the Maintenance
       Intermediate Point(MIP) needs to be explicit configured";
    }

    identity technology-types {
      description
        "This is the base identy of technology types which are
       TRILL, MPLS-TP, etc";
    }

    identity command-sub-type {
      description
        "Defines different rpc command subtypes,
       e.g rfc6905 trill OAM, this is optional for most cases";
    }

    identity on-demand {
      base command-sub-type;
      description
        "On demand activation - indicates that the tool is activated
       manually to detect a specific anomaly.
       On-demand OAM method requires only transient configuration.";
    }

    identity proactive {
      base command-sub-type;
      description
        "Proactive activation - indicates that the tool is activated on a
       continual basis, where messages are sent periodically, and errors
       are detected when a certain number of expected messages are not
       received. Proactive OAM method requires persistent
       configuration.";
    }

    identity name-format {
      description
        "This defines the name format, IEEE 8021ag CFM defines varying
       styles of names. It is expected name format as an identity ref
       to be extended with new types.";
    }

    identity name-format-null {
      base name-format;
      description
        "Defines name format as null";
    }

    identity identifier-format {
      description
        "Identifier-format identity can be augmented to define other
       format identifiers used in MEP-ID etc";
    }

    identity identifier-format-integer {
      base identifier-format;
      description
        "Defines identifier-format to be integer";
    }

    identity defect-types {
      description
        "Defines different defect types, e.g.
       Remote Defect Indication (rdi), loss of continuity";
    }

    identity rdi {
      base defect-types;
      description
        "The Remote Defect Indication (rdi) indicates the
       aggregate health of the remote Maintenance End Points (MEPs).";
    }

    identity remote-mep-defect {
      base defect-types;
      description
        "Indicates that one or more of the remote
       Maintenance End Points(MEPs)is reporting a failure ";
    }

    identity loss-of-continuity {
      base defect-types;
      description
        "If no proactive Continuity Check (CC)
       OAM packets from the source Maintenance End Point
       (MEP) (and in the case of Connectivity
       Verification , this includes the
       requirement to have the expected unique,
       technology dependent source MEP
       identifier) are received within the interval.";
    }

    identity cv-defect {
      base defect-types;
      description
        "This function should support monitoring between
       the Maintenance End Points (MEPs) and,
       in addition, between a MEP and Maintenance Intermediate
       Point (MIP). [RFC6371] highlights, when performing
       Connectivity Verification, the need for the Continuity
       Check and Connectivity Verification (CC-V) messages
       to include unique identification of the MEG that is being
       monitored and the MEP that originated the message.";
    }

    identity invalid-oam-defect {
      base defect-types;
      description
        "Indicates that one or more invalid OAM messages has been
       received and that 3.5 times that OAM message transmission
       interval has not yet expired.";
    }

    identity cross-connect-defect {
      base defect-types;
      description
        "Indicates that one or more cross-connect defect
       (for example, a service ID does not match the VLAN.)
       messages has been received and that 3.5 times that OAM message
       transmission interval has not yet expired.";
    }

    typedef mep-name {
      type string;
      description
        "Generic administrative name for a Maintenance End Point
       (MEP).";
    }

    typedef time-interval {
      type decimal64 {
        fraction-digits 2;
      }
      units "milliseconds";
      description
        "Time interval between packets in milliseconds.
       0 means no packets are sent.";
    }

    typedef md-name-string {
      type string;
      description
        "Generic administrative name for Maintenance Domain (MD).";
    }

    typedef ma-name-string {
      type string;
      description
        "Generic administrative name for an
       Maintenance Association (MA).";
    }

    typedef oam-counter32 {
      type yang:zero-based-counter32;
      description
        "Define 32 bit counter for OAM.";
    }

    typedef md-level {
      type uint32 {
        range "0..255";
      }
      description
        "Maintenance Domain level.  The level may be restricted in
       certain protocols (e.g., protocol in layer 0 to layer 7).";
    }

    container domains {
      description
        "Contains configuration related data. Within the container
       is list of fault domains. Within each domian has List of
       Maintenance Association (MA).";
      list domain {
        key "technology md-name-string";
        description
          "Define the list of fault Domains within the
         ietf-connection-oriented-oam module.";
        leaf technology {
          type identityref {
            base technology-types;
          }
          mandatory true;
          description
            "Defines the technology.";
        }

        leaf md-name-string {
          type md-name-string;
          mandatory true;
          description
            "Defines the generic administrative maintenance domain name.";
        }

        leaf md-name-format {
          type identityref {
            base name-format;
          }
          description
            "Maintenance Domain Name format.";
        }

        choice md-name {
          description
            "Maintenance Domain (MD) name.";
          leaf md-name-null {
            when
              "derived-from-or-self(../md-name-format,'name-format-null')" {
              description
                "Maintenance Domain (MD) name
format is equal to null format.";
            }
            type empty;
            description
              "Maintenance Domain (MD) name Null.";
          }
        }  // choice md-name

        leaf md-level {
          type md-level;
          description "Define the MD-Level.";
        }

        container mas {
          description
            "This container defines Maintenance Association (MA),
           within that have multiple MA and within MA have
           Maintenance End Point (MEP).";
          list ma {
            key "ma-name-string";
            description
              "Maintenance Association list.";
            leaf ma-name-string {
              type ma-name-string;
              description
                "Maintenance Association (MA) name string.";
            }

            leaf ma-name-format {
              type identityref {
                base name-format;
              }
              description
                "Maintenance Association (MA) name format.";
            }

            choice ma-name {
              description
                "Maintenance Association) name(MA).";
              leaf ma-name-null {
                when
                  "derived-from-or-self(../ma-name-format, 'name-format-null')" {
                  description
                    "Maintenance Association (MA).";
                }
                type empty;
                description "Empty";
              }
            }  // choice ma-name

            choice connectivity-context {
              default "context-null";
              description
                "Connectivity context.";
              case context-null {
                description
                  "This is a place holder when no context is needed.";
                leaf context-null {
                  type empty;
                  description
                    "There is no context to be defined.";
                }
              }  // case context-null
            }  // choice connectivity-context

            leaf cos-id {
              type uint8;
              description
                "Class of Service(CoS) id, this value is used to indicate
Class of Service information .";
            }

            leaf cc-enable {
              type boolean;
              description
                "Indicate whether the
               Continuity Check (CC) is enabled.";
            }

            list mep {
              key "mep-name";
              description
                "Contain a list of Maintenance End Points (MEPs)";
              leaf mep-name {
                type mep-name;
                mandatory true;
                description
                  "Generic administrative name of the
Maintenance End Point (MEP).";
              }

              choice mep-id {
                default "mep-id-int";
                description
                  "Maintenance End Point (MEP) ID.";
                leaf mep-id-int {
                  type int32;
                  description
                    "Maintenance End Point (MEP) ID
in integer format.";
                }
              }  // choice mep-id

              leaf mep-id-format {
                type identityref {
                  base identifier-format;
                }
                description
                  "Maintenance End Point (MEP) ID format.";
              }

              choice mep-address {
                description
                  "Maintenance End Point (MEP) Addressing.";
                case mac-address {
                  description
                    "MAC Address based Maintenance End Point (MEP) Addressing.";
                  leaf mac-address {
                    type yang:mac-address;
                    description
                      "MAC Address.";
                  }
                }  // case mac-address

                case ip-address {
                  description
                    "IP Address based Maintenance End Point(MEP) Addressing.";
                  leaf ip-address {
                    type inet:ip-address;
                    description
                      "IP Address.";
                  }
                }  // case ip-address
              }  // choice mep-address

              leaf cos-id {
                type uint8;
                description
                  "Class of Service(CoS) id, this value is used to indicate
Class of Service information .";
              }

              leaf cc-enable {
                type boolean;
                description
                  "Indicate whether the Continuity Check (CC)is enabled.";
              }

              list session {
                key "session-cookie";
                description
                  "Monitoring session to/from a particular
                 remote Maintenance End Point (MEP).
                 Depending on the protocol, this could represent
                 Continuity Check (CC) messages received from
                 a single remote MEP (if the protocol uses
                 multicast CCs) or a target to which
                 unicast echo request CCs are sent and from which
                 responses are received (if the protocol uses a

                 unicast request/response mechanism).";
                leaf session-cookie {
                  type uint32;
                  description
                    "Cookie to identify different sessions, when there
                   are multiple remote Maintenance End Point(MEP)
                   or multiple sessions tothe same remote MEP.";
                }

                container destination-mep {
                  description
                    "Destination Maintenance End Point(MEP).";
                  choice mep-id {
                    default "mep-id-int";
                    description
                      "Maintenance End Point (MEP) ID.";
                    leaf mep-id-int {
                      type int32;
                      description
                        "Maintenance End Point (MEP) ID
in integer format.";
                    }
                  }  // choice mep-id

                  leaf mep-id-format {
                    type identityref {
                      base identifier-format;
                    }
                    description
                      "Maintenance End Point (MEP) ID format.";
                  }
                }  // container destination-mep

                container destination-mep-address {
                  description
                    "Destination Maintenance End Point (MEP) Address.";
                  choice mep-address {
                    description
                      "Maintenance End Point (MEP) Addressing.";
                    case mac-address {
                      description
                        "MAC Address based Maintenance End Point (MEP) Addressing.";
                      leaf mac-address {
                        type yang:mac-address;
                        description
                          "MAC Address.";
                      }
                    }  // case mac-address

                    case ip-address {
                      description
                        "IP Address based Maintenance End Point(MEP) Addressing.";
                      leaf ip-address {
                        type inet:ip-address;
                        description
                          "IP Address.";
                      }
                    }  // case ip-address
                  }  // choice mep-address
                }  // container destination-mep-address

                leaf cos-id {
                  type uint8;
                  description
                    "Class of Service(CoS) id, this value is used to indicate
Class of Service information .";
                }
              }  // list session
            }  // list mep

            list mip {
              if-feature mip;
              key "name";
              description
                "List for Maintenance Intermediate Point (MIP).";
              leaf name {
                type string;
                description
                  "Identifier of Maintenance intermediate point";
              }

              leaf interface {
                type if:interface-ref;
                description "Interface";
              }

              choice mip-address {
                description
                  "Maintenance Intermediate Point (MIP) Addressing.";
                case mac-address {
                  description
                    "MAC Address based Maintenance Intermediate
Point (MIP) Addressing.";
                  leaf mac-address {
                    type yang:mac-address;
                    description
                      "MAC Address of Maintenance Intermediate Point";
                  }
                }  // case mac-address

                case ip-address {
                  description
                    "IP Address based Maintenance Intermediate Point(MIP)
Addressing.";
                  leaf ip-address {
                    type inet:ip-address;
                    description
                      "IP Address.";
                  }
                }  // case ip-address
              }  // choice mip-address
            }  // list mip
          }  // list ma
        }  // container mas
      }  // list domain
    }  // container domains

    notification defect-condition-notification {
      description
        "Upon the defect condition is met, this
       notification is sent";
      leaf technology {
        type identityref {
          base technology-types;
        }
        description "The technology";
      }

      leaf md-name-string {
        type leafref {
          path "/domains/domain/md-name-string";
        }
        mandatory true;
        description
          "Indicate which Maintenance Domain(MD)
         does the defect belong to.";
      }

      leaf ma-name-string {
        type leafref {
          path "/domains/domain/mas/ma/ma-name-string";
        }
        mandatory true;
        description
          "Indicate which Maintenance Association (MA)
         is the defect associated with.";
      }

      leaf mep-name {
        type leafref {
          path "/domains/domain/mas/ma/mep/mep-name";
        }
        description
          "Indicate which Maintenance End Point(MEP)
         is seeing the defect.";
      }

      leaf defect-type {
        type identityref {
          base defect-types;
        }
        description
          "The currently active defects on the specific
         Maintenance End Point (MEP).";
      }

      container generating-mepid {
        description
          "Indicate who is generating the defect (if known). If
         unknown set it as 0.";
        choice mep-id {
          default "mep-id-int";
          description
            "Maintenance End Point (MEP) ID.";
          leaf mep-id-int {
            type int32;
            description
              "Maintenance End Point (MEP) ID
in integer format.";
          }
        }  // choice mep-id

        leaf mep-id-format {
          type identityref {
            base identifier-format;
          }
          description
            "Maintenance End Point (MEP) ID format.";
        }
      }  // container generating-mepid

      choice defect {
        description
          "Defect Message choices.";
        case defect-null {
          description
            "This is a placeholder when no defect status is needed";
          leaf defect-null {
            type empty;
            description
              "There is no defect to be defined, it will be defined in
technology specific model.";
          }
        }  // case defect-null

        case defect-code {
          description
            "This is a placeholder to display defect code.";
          leaf defect-code {
            type int32;
            description
              "Defect code is integer value specific to a technology.";
          }
        }  // case defect-code
      }  // choice defect
    }  // notification defect-condition-notification

    notification defect-cleared-notification {
      description
        "Upon defect cleared is met, this notification is sent";
      leaf technology {
        type identityref {
          base technology-types;
        }
        description "The technology.";
      }

      leaf md-name-string {
        type leafref {
          path "/domains/domain/md-name-string";
        }
        mandatory true;
        description
          "Indicate which Maintenance Domain (MD)
         does the defect belong to";
      }

      leaf ma-name-string {
        type leafref {
          path "/domains/domain/mas/ma/ma-name-string";
        }
        mandatory true;
        description
          "Indicate which Maintenance Association (MA)
         is the defect associated with.";
      }

      leaf mep-name {
        type leafref {
          path "/domains/domain/mas/ma/mep/mep-name";
        }
        description
          "Indicate which Maintenance End Point (MEP)
         is seeing the defect.";
      }

      leaf defect-type {
        type identityref {
          base defect-types;
        }
        description
          "The currently active defects on the
         specific Maintenance End Point (MEP).";
      }

      container generating-mepid {
        description
          "Indicate who is generating the defect (if known). if
         unknown set it as 0.";
        choice mep-id {
          default "mep-id-int";
          description
            "Maintenance End Point (MEP) ID.";
          leaf mep-id-int {
            type int32;
            description
              "Maintenance End Point (MEP) ID
in integer format.";
          }
        }  // choice mep-id

        leaf mep-id-format {
          type identityref {
            base identifier-format;
          }
          description
            "Maintenance End Point (MEP) ID format.";
        }
      }  // container generating-mepid

      choice defect {
        description
          "Defect Message choices.";
        case defect-null {
          description
            "This is a placeholder when no defect status is needed";
          leaf defect-null {
            type empty;
            description
              "There is no defect to be defined, it will be defined in
technology specific model.";
          }
        }  // case defect-null

        case defect-code {
          description
            "This is a placeholder to display defect code.";
          leaf defect-code {
            type int32;
            description
              "Defect code is integer value specific to a technology.";
          }
        }  // case defect-code
      }  // choice defect
    }  // notification defect-cleared-notification

    rpc continuity-check {
      if-feature continuity-check;
      description
        "Generates continuity-check as per RFC7276 Table 4.";
      input {
        leaf technology {
          type identityref {
            base technology-types;
          }
          description "The technology";
        }

        leaf md-name-string {
          type leafref {
            path "/domains/domain/md-name-string";
          }
          mandatory true;
          description
            "Indicate which Maintenance Domain (MD)
           does the defect belong to.";
        }

        leaf md-level {
          type leafref {
            path "/domains/domain/md-level";
          }
          description
            "The maintenance domain level.";
        }

        leaf ma-name-string {
          type leafref {
            path "/domains/domain/mas/ma/ma-name-string";
          }
          mandatory true;
          description
            "Indicate which MA is the defect associated with";
        }

        leaf cos-id {
          type uint8;
          description
            "Class of Service(CoS) id, this value is used to indicate
Class of Service information .";
        }

        leaf ttl {
          type uint8;
          description "Time to Live.";
        }

        leaf sub-type {
          type identityref {
            base command-sub-type;
          }
          description
            "Defines different command types.";
        }

        leaf source-mep {
          type leafref {
            path "/domains/domain/mas/ma/mep/mep-name";
          }
          description
            "Source Maintenance End Point (MEP).";
        }

        container destination-mep {
          description
            "Destination Maintenance End Point (MEP).";
          choice mep-address {
            description
              "Maintenance End Point (MEP) Addressing.";
            case mac-address {
              description
                "MAC Address based Maintenance End Point (MEP) Addressing.";
              leaf mac-address {
                type yang:mac-address;
                description "MAC Address.";
              }
            }  // case mac-address

            case ip-address {
              description
                "IP Address based Maintenance End Point(MEP) Addressing.";
              leaf ip-address {
                type inet:ip-address;
                description "IP Address.";
              }
            }  // case ip-address
          }  // choice mep-address

          choice mep-id {
            default "mep-id-int";
            description
              "Maintenance End Point (MEP) ID.";
            leaf mep-id-int {
              type int32;
              description
                "Maintenance End Point (MEP) ID
in integer format.";
            }
          }  // choice mep-id

          leaf mep-id-format {
            type identityref {
              base identifier-format;
            }
            description
              "Maintenance End Point (MEP) ID format.";
          }
        }  // container destination-mep

        leaf count {
          type uint32;
          default "3";
          description
            "Number of continuity-check message to be sent.";
        }

        leaf cc-transmit-interval {
          type time-interval;
          description
            "Time interval between echo requests.";
        }

        leaf packet-size {
          type uint32 {
            range "64..10000";
          }
          description
            "Size of continuity-check packets, in octets.";
        }
      }

      output {
        choice monitor-stats {
          default "monitor-null";
          description
            "Define the monitor stats.";
          case monitor-null {
            description
              "This is a place holder when
no monitoring statistics is needed";
            leaf monitor-null {
              type empty;
              description
                "There is no monitoring statistics to be defined.";
            }
          }  // case monitor-null
        }  // choice monitor-stats
      }
    }  // rpc continuity-check

    rpc continuity-verification {
      if-feature connectivity-verification;
      description
        "Generates continuity-verification as per RFC7276 Table 4.";
      input {
        leaf md-name-string {
          type leafref {
            path "/domains/domain/md-name-string";
          }
          mandatory true;
          description
            "Indicate which MD (Maintenance Domain)
           does the defect belong to.";
        }

        leaf md-level {
          type leafref {
            path "/domains/domain/md-level";
          }
          description
            "The maintenance domain level.";
        }

        leaf ma-name-string {
          type leafref {
            path "/domains/domain/mas/ma/ma-name-string";
          }
          mandatory true;
          description
            "Indicate which Maintenance Association (MA)
           is the defect associated with.";
        }

        leaf cos-id {
          type uint8;
          description
            "Class of Service(CoS) id, this value is used to indicate
Class of Service information .";
        }

        leaf ttl {
          type uint8;
          description "Time to Live.";
        }

        leaf sub-type {
          type identityref {
            base command-sub-type;
          }
          description
            "Defines different command types.";
        }

        leaf source-mep {
          type leafref {
            path "/domains/domain/mas/ma/mep/mep-name";
          }
          description
            "Source Maintenance End Point(MEP).";
        }

        container destination-mep {
          description
            "Destination Maintenance End Point(MEP).";
          choice mep-address {
            description
              "Maintenance End Point (MEP) Addressing.";
            case mac-address {
              description
                "MAC Address based Maintenance End Point (MEP) Addressing.";
              leaf mac-address {
                type yang:mac-address;
                description "MAC Address.";
              }
            }  // case mac-address

            case ip-address {
              description
                "IP Address based Maintenance End Point(MEP) Addressing.";
              leaf ip-address {
                type inet:ip-address;
                description "IP Address.";
              }
            }  // case ip-address
          }  // choice mep-address

          choice mep-id {
            default "mep-id-int";
            description
              "Maintenance End Point (MEP) ID.";
            leaf mep-id-int {
              type int32;
              description
                "Maintenance End Point (MEP) ID
in integer format.";
            }
          }  // choice mep-id

          leaf mep-id-format {
            type identityref {
              base identifier-format;
            }
            description
              "Maintenance End Point (MEP) ID format.";
          }
        }  // container destination-mep

        leaf count {
          type uint32;
          default "3";
          description
            "Number of continuity-verification message to be sent.";
        }

        leaf interval {
          type time-interval;
          description
            "Time interval between echo requests.";
        }

        leaf packet-size {
          type uint32 {
            range "64..10000";
          }
          description
            "Size of continuity-verification packets, in octets";
        }
      }

      output {
        choice monitor-stats {
          default "monitor-null";
          description
            "Define the monitor stats.";
          case monitor-null {
            description
              "This is a place holder when
no monitoring statistics is needed";
            leaf monitor-null {
              type empty;
              description
                "There is no monitoring statistics to be defined.";
            }
          }  // case monitor-null
        }  // choice monitor-stats
      }
    }  // rpc continuity-verification

    rpc traceroute {
      if-feature traceroute;
      description
        "Generates Traceroute or Path Trace and return response.
       Referencing RFC7276 for common Toolset name, for
       MPLS-TP OAM it's Route Tracing, and for TRILL OAM It's
       Path Tracing tool. Starts with TTL of one and increment
       by one at each hop. Untill destination reached or TTL
       reach max value.";
      input {
        leaf md-name-string {
          type leafref {
            path "/domains/domain/md-name-string";
          }
          mandatory true;
          description
            "Indicate which Maintenance Domain (MD)
           does the defect belong to.";
        }

        leaf md-level {
          type leafref {
            path "/domains/domain/md-level";
          }
          description
            "The maintenance domain level.";
        }

        leaf ma-name-string {
          type leafref {
            path "/domains/domain/mas/ma/ma-name-string";
          }
          mandatory true;
          description
            "Indicate which Maintenance Association (MA)
           is the defect associated with.";
        }

        leaf cos-id {
          type uint8;
          description
            "Class of Service(CoS) id, this value is used to indicate
Class of Service information .";
        }

        leaf ttl {
          type uint8;
          description "Time to Live.";
        }

        leaf command-sub-type {
          type identityref {
            base command-sub-type;
          }
          description
            "Defines different command types.";
        }

        leaf source-mep {
          type leafref {
            path "/domains/domain/mas/ma/mep/mep-name";
          }
          description
            "Source Maintenance End Point (MEP).";
        }

        container destination-mep {
          description
            "Destination Maintenance End Point (MEP).";
          choice mep-address {
            description
              "Maintenance End Point (MEP) Addressing.";
            case mac-address {
              description
                "MAC Address based Maintenance End Point (MEP) Addressing.";
              leaf mac-address {
                type yang:mac-address;
                description "MAC Address.";
              }
            }  // case mac-address

            case ip-address {
              description
                "IP Address based Maintenance End Point(MEP) Addressing.";
              leaf ip-address {
                type inet:ip-address;
                description "IP Address.";
              }
            }  // case ip-address
          }  // choice mep-address

          choice mep-id {
            default "mep-id-int";
            description
              "Maintenance End Point (MEP) ID.";
            leaf mep-id-int {
              type int32;
              description
                "Maintenance End Point (MEP) ID
in integer format.";
            }
          }  // choice mep-id

          leaf mep-id-format {
            type identityref {
              base identifier-format;
            }
            description
              "Maintenance End Point (MEP) ID format.";
          }
        }  // container destination-mep

        leaf count {
          type uint32;
          default "1";
          description
            "Number of traceroute probes to send. In protocols where a
           separate message is sent at each TTL, this is the number
           of packets to be sent at each TTL.";
        }

        leaf interval {
          type time-interval;
          description
            "Time interval between echo requests.";
        }
      }

      output {
        list response {
          key "response-index";
          description "List of response.";
          leaf response-index {
            type uint8;
            description
              "Arbitrary index for the response.  In protocols that
             guarantee there is only a single response at each TTL,
             the TTL can be used as the response index.";
          }

          leaf ttl {
            type uint8;
            description "Time to Live.";
          }

          container destination-mep {
            description
              "Maintenance End Point (MEP) from
             which the response has been received";
            choice mep-address {
              description
                "Maintenance End Point (MEP) Addressing.";
              case mac-address {
                description
                  "MAC Address based Maintenance End Point (MEP) Addressing.";
                leaf mac-address {
                  type yang:mac-address;
                  description "MAC Address.";
                }
              }  // case mac-address

              case ip-address {
                description
                  "IP Address based Maintenance End Point(MEP) Addressing.";
                leaf ip-address {
                  type inet:ip-address;
                  description "IP Address.";
                }
              }  // case ip-address
            }  // choice mep-address

            choice mep-id {
              default "mep-id-int";
              description
                "Maintenance End Point (MEP) ID.";
              leaf mep-id-int {
                type int32;
                description
                  "Maintenance End Point (MEP) ID
in integer format.";
              }
            }  // choice mep-id

            leaf mep-id-format {
              type identityref {
                base identifier-format;
              }
              description
                "Maintenance End Point (MEP) ID format.";
            }
          }  // container destination-mep

          container mip {
            if-feature mip;
            description
              "Maintenance Intermediate Point (MIP)
             responding with traceroute";
            leaf interface {
              type if:interface-ref;
              description
                "Maintenance Intermediate Point (MIP) interface.";
            }

            choice mip-address {
              description
                "Maintenance Intermediate Point (MIP) Addressing.";
              case mac-address {
                description
                  "MAC Address based Maintenance Intermediate
Point (MIP) Addressing.";
                leaf mac-address {
                  type yang:mac-address;
                  description
                    "MAC Address of Maintenance Intermediate Point";
                }
              }  // case mac-address

              case ip-address {
                description
                  "IP Address based Maintenance Intermediate Point(MIP)
Addressing.";
                leaf ip-address {
                  type inet:ip-address;
                  description "IP Address.";
                }
              }  // case ip-address
            }  // choice mip-address
          }  // container mip

          choice monitor-stats {
            default "monitor-null";
            description
              "Define the monitor stats.";
            case monitor-null {
              description
                "This is a place holder when
no monitoring statistics is needed";
              leaf monitor-null {
                type empty;
                description
                  "There is no monitoring statistics to be defined.";
              }
            }  // case monitor-null
          }  // choice monitor-stats
        }  // list response
      }
    }  // rpc traceroute
  }  // module ietf-connection-oriented-oam