module ieee802-ethernet-link-oam {

    yang-version 1.1;

    namespace
      "urn:ieee:std:802.3:yang:ieee802-ethernet-link-oam";

    prefix ieee802-link-oam;

    import ieee802-types {
      prefix ieee;
      reference
        "IEEE 802 types";


    }
    import ietf-yang-types {
      prefix yang;
      reference
        "IETF RFC 6991";


    }
    import iana-if-type {
      prefix ianaift;
      reference
        "http://www.iana.org/assignments/yang-parameters/
        iana-if-type@2023-01-26.yang";


    }
    import ietf-interfaces {
      prefix if;
      reference
        "IETF RFC 8343";


    }

    organization
      "IEEE 802.3 Ethernet Working Group
     Web URL: http://www.ieee802.org/3/";

    contact
      "Web URL: http://www.ieee802.org/3/";

    description
      "This module contains a collection of YANG definitions
     for managing the Ethernet Link OAM feature defined by IEEE
     802.3. It provides functionality roughly equivalent to that of
     the DOT3-OAM-MIB defined in IETF RFC 4878.";

    revision "2025-04-17" {
      description
        "Updates under IEEE Std 802.3.2-202x, Draft D3.3";
      reference
        "IEEE Std 802.3-2022, unless dated explicitly";

    }


    feature uni-directional-link-fault {
      description
        "This feature means the device supports Uni Directional Link
       Fault detection.";
      reference
        "IEEE Std 802.3, 57.1.2:a, 30.3.6.1.6 aOAMLocalConfiguration
        and 30.3.6.1.7 aOAMRemoteConfiguration";

    }

    feature remote-loopback-initiate {
      description
        "This feature means the device supports being the initiator
       of remote loopback.";
      reference
        "IEEE Std 802.3, 57.1.2:b, 30.3.6.1.6
        aOAMLocalConfiguration";

    }

    feature remote-loopback-respond {
      description
        "This feature means the device supports responding to remote
       loopback control OAMPDUs received from the peer";
      reference
        "IEEE Std 802.3, 57.1.2:b, 30.3.6.1.7
        aOAMRemoteConfiguration";

    }

    feature link-monitoring-local {
      description
        "This feature means the device monitors the link at the local
       side and can generate Link Event OAMPDUs to the peer
       device.";
      reference
        "IEEE Std 802.3, 57.1.2:c:1, 30.3.6.1.6
        aOAMLocalConfiguration, and 30.3.6.1.7
        aOAMRemoteConfiguration";

    }

    feature link-monitoring-remote {
      description
        "This feature means the device can process Link Event OAMPDUs
       received from the peer device and report itself about this
       event on its own management interface.";
      reference
        "IEEE Std 802.3, 57.1.2:c:1,
        30.3.6.1.6 aOAMLocalConfiguration,
        and 30.3.6.1.7 aOAMRemoteConfiguration";

    }

    feature remote-mib-retrieval-initiate {
      status deprecated;
      description
        "remote-mib-retrieval-initiate is deprecated and changed name
       to feature remote-data-retrieval-initiate. This feature
       means the device supports data retrieval from the peer
       device. I.e. the device can send Variable Requests OAMPDUs
       to the peer side and process the received Variable Response
       OAMPDUs.";
      reference
        "IEEE Std 802.3, 57.1.2:c:2,
        30.3.6.1.6 aOAMLocalConfiguration,
        and 30.3.6.1.7 aOAMRemoteConfiguration";

    }

    feature remote-data-retrieval-initiate {
      description
        "This feature means the device supports data retrieval from
       the peer device. I.e. the device can send Variable Requests
       OAMPDUs to the peer side and process the received Variable
       Response OAMPDUs.";
      reference
        "IEEE Std 802.3, 57.1.2:c:2,
        30.3.6.1.6 aOAMLocalConfiguration,
        and 30.3.6.1.7 aOAMRemoteConfiguration";

    }

    feature remote-mib-retrieval-respond {
      description
        "This feature means the device allows the peer device to
       retrieve data from the managed device. I.e. the device can
       process received Variable Requests OAMPDUs and respond with
       Variable Response OAMPDUs.";
      reference
        "IEEE Std 802.3, 57.1.2:c:2,
        30.3.6.1.6 aOAMLocalConfiguration,
        and 30.3.6.1.7 aOAMRemoteConfiguration";

    }

    identity event-type {
      description
        "Base identity for all Link OAM event types.";
    }

    identity threshold-event-type {
      base event-type;
      description
        "Event type for a Link Monitoring threshold event.";
    }

    identity link-fault-event {
      base event-type;
      description
        "Event type for a uni-directional link fault event.";
      reference
        "IEEE Std 802.3, 57.2.10.1";

    }

    identity dying-gasp-event {
      base event-type;
      description
        "Event type for a dying gasp event.";
      reference
        "IEEE Std 802.3, 57.2.10.1";

    }

    identity critical-event {
      base event-type;
      description
        "Event type for a critical event.";
      reference
        "IEEE Std 802.3, 57.2.10.1";

    }

    typedef threshold-event-enum {
      type enumeration {
        enum "symbol-period-event" {
          value 1;
          description
            "Errored symbol period event.";
        }
        enum "frame-period-event" {
          value 2;
          description
            "Errored frame period event.";
        }
        enum "frame-event" {
          value 3;
          description "Errored frame event";
        }
        enum "frame-seconds-event" {
          value 4;
          description
            "Errored frame seconds event.";
        }
      }
      description
        "Enumeration of the valid threshold event types.";
      reference
        "IEEE Std 802.3, 57.5.3";

    }

    typedef mode {
      type enumeration {
        enum "passive" {
          value 0;
          description
            "Ethernet Link OAM Passive mode.";
        }
        enum "active" {
          value 1;
          description
            "Ethernet Link OAM Active mode.";
        }
      }
      description
        "Enumeration of the valid modes in which Link OAM may run.";
      reference
        "IEEE Std 802.3, 57.2.9 and 30.3.6.1.3.";

    }

    typedef event-location {
      type enumeration {
        enum "event-location-local" {
          value 1;
          description "A local event.";
        }
        enum "event-location-remote" {
          value 2;
          description "A remote event.";
        }
      }
      description
        "The location of the event that caused a log entry.";
    }

    typedef loopback-status {
      type enumeration {
        enum "none" {
          value 1;
          description
            "Loopback is not being performed.";
        }
        enum "initiating" {
          value 2;
          description
            "Initiating master loopback.";
        }
        enum "master-loopback" {
          value 3;
          description
            "In master loopback mode.";
        }
        enum "terminating" {
          value 4;
          description
            "Terminating master loopback mode.";
        }
        enum "local-loopback" {
          value 5;
          description
            "In slave loopback mode.";
        }
        enum "unknown" {
          value 6;
          description
            "Parser and multiplexer combination unexpected.";
        }
      }
      description
        "The loopback mode of an OAM interface.";
      reference
        "IEEE Std 802.3, 57.2.11";

    }

    typedef operational-state {
      type enumeration {
        enum "disabled" {
          value 1;
          description
            "IEEE Std 802.3 OAM is disabled.";
        }
        enum "link-fault" {
          value 2;
          description
            "IEEE Std 802.3 OAM has encountered a link fault.";
        }
        enum "passive-wait" {
          value 3;
          description
            "Passive OAM entity waiting to see if peer is
           OAM capable.";
        }
        enum "active-send-local" {
          value 4;
          description
            "Active OAM entity trying to determine if peer
           is OAM capable.";
        }
        enum "send-local-and-remote" {
          value 5;
          description
            "OAM discovered peer but still to accept or
           reject peer configuration.";
        }
        enum "send-local-and-remote-ok" {
          value 6;
          description
            "OAM peering is allowed by local device.";
        }
        enum "peering-locally-rejected" {
          value 7;
          description
            "OAM peering rejected by local device.";
        }
        enum "peering-remotely-rejected" {
          value 8;
          description
            "OAM peering rejected by remote device.";
        }
        enum "operational" {
          value 9;
          description
            "IEEE Std 802.3 OAM is operational.";
        }
        enum "operational-half-duplex" {
          value 10;
          description
            "IEEE Std 802.3 OAM is operating in half-duplex mode.";
        }
      }
      description
        "Operational state of an interface.";
      reference
        "IEEE Std 802.3, 30.3.6.1.4,
        30.3.6.1.10, and 30.3.6.1.11";

    }

    typedef vendor-oui {
      type string {
        length "6";
      }
      description
        "Organizationally Unique Identifier (OUI) as assigned to
       vendor by the IEEE Registration Authority";
      reference
        "IEEE Std 802, subclause 8.2.2";

    }

    typedef admin-state {
      type enumeration {
        enum "enabled" {
          value 1;
          description
            "IEEE Std 802.3, Clause 57 OAM is in the
           enabled admin state.";
        }
        enum "disabled" {
          value 2;
          description
            "IEEE Std 802.3, Clause 57 OAM is in the
           disabled admin state.";
        }
      }
      description
        "Admin state of the OAM function on an interface.";
      reference
        "IEEE Std 802.3, 30.3.6.1.2 and 30.3.6.2";

    }

    grouping event-details {
      description
        "Nodes describing an event, used in the event log and in
       notifications.";
      reference
        "IETF RFC 4878, Dot3OamEventLogEntry";

      leaf oui {
        type vendor-oui;
        mandatory true;
        description
          "Organizationally Unique Identifier for the device that
         generated the event.";
      }

      leaf timestamp {
        type uint64;
        units "milliseconds";
        mandatory true;
        description
          "Timestamp in milliseconds since Unix epoch for when the
         event occurred.";
      }

      leaf location {
        type event-location;
        mandatory true;
        description
          "Where the event occurred (local or remote).";
      }

      leaf event-type {
        type identityref {
          base event-type;
        }
        mandatory true;
        description
          "Type of event that occurred.";
        reference
          "IEEE Std 802.3, 30.3.6.1.10 and 30.3.6.11";

      }

      leaf running-total {
        type yang:counter64;
        mandatory true;
        description
          "The running total number of errors seen since OAM was
         enabled on the interface. For threshold events, this is
         the total number of times that particular type of error
         (e.g. symbol error) has occurred, which may be greater
         than the number of threshold-crossing event notifications
         of that type generated during that time (which is conveyed
         by the event-total leaf).";
      }

      leaf event-total {
        type yang:counter64;
        mandatory true;
        description
          "Total number of times this event has occurred since OAM
         was enabled on the interface. For threshold events this is
         the number of events generated of this type (as opposed to
         the total number of errors of that type, which may be
         greater, and is conveyed by the running-total leaf.";
      }
    }  // grouping event-details

    grouping threshold-event-details {
      description
        "Nodes describing a threshold event, used in the event
       log and in notifications";
      reference
        "IETF RFC 4878, Dot3OamEventLogEntry";

      container threshold {
        when
          "../event-type = 'ieee802-link-oam:threshold-event-type'" {
          description
            "These nodes only apply to threshold event types";
        }
        if-feature link-monitoring-local or
link-monitoring-remote;
        description
          "Nodes specific to threshold (link monitoring) events";
        leaf threshold-event-type {
          type threshold-event-enum;
          mandatory true;
          description
            "The type of threshold event";
          reference
            "IEEE Std 802.3, 57.5.3";

        }

        leaf window {
          type uint64;
          mandatory true;
          description
            "Size of the window in which the event was generated.
           Units are dependent on the threshold event type.";
        }

        leaf threshold {
          type uint64;
          mandatory true;
          description
            "Size of the threshold that was breached during the
           window. Units are dependent on the threshold
           event type.";
        }

        leaf value {
          type uint64;
          mandatory true;
          description
            "Breaching value. Units are dependent on the threshold
           event type, and match that of the threshold.";
        }
      }  // container threshold
    }  // grouping threshold-event-details

    grouping statistics-common {
      description
        "Collection of Link OAM event/packet counters.";
      reference
        "IETF RFC 4878, Dot3OamStatsEntry";

      leaf out-information {
        type yang:counter64;
        mandatory true;
        description
          "Number of information OAMPDUs transmitted.";
        reference
          "IEEE Std 802.3, 30.3.6.1.20";

      }

      leaf in-information {
        type yang:counter64;
        mandatory true;
        description
          "Number of information OAMPDUs received.";
        reference
          "IEEE Std 802.3, 30.3.6.1.21";

      }

      leaf out-unique-event-notification {
        if-feature link-monitoring-local;
        type yang:counter64;
        mandatory true;
        description
          "Number of unique event notification OAMPDUs transmitted.";
        reference
          "IEEE Std 802.3, 30.3.6.1.22";

      }

      leaf in-unique-event-notification {
        if-feature link-monitoring-remote;
        type yang:counter64;
        mandatory true;
        description
          "Number of unique event notification OAMPDUs received.";
        reference
          "IEEE Std 802.3, 30.3.6.1.24";

      }

      leaf out-duplicate-event-notification {
        if-feature link-monitoring-local;
        type yang:counter64;
        mandatory true;
        description
          "Number of duplicate event notification OAMPDUs
                 transmitted.";
        reference
          "IEEE Std 802.3, 30.3.6.1.23";

      }

      leaf in-duplicate-event-notification {
        if-feature link-monitoring-remote;
        type yang:counter64;
        mandatory true;
        description
          "Number of duplicate event notification OAMPDUs
         received.";
        reference
          "IEEE Std 802.3, 30.3.6.1.25";

      }

      leaf out-loopback-control {
        if-feature remote-loopback-initiate;
        type yang:counter64;
        mandatory true;
        description
          "Number of loopback control OAMPDUs transmitted.";
        reference
          "IEEE Std 802.3, 30.3.6.1.26";

      }

      leaf in-loopback-control {
        if-feature remote-loopback-respond;
        type yang:counter64;
        mandatory true;
        description
          "Number of loopback control OAMPDUs received.";
        reference
          "IEEE Std 802.3, 30.3.6.1.27";

      }

      leaf out-variable-request {
        if-feature remote-data-retrieval-initiate;
        type yang:counter64;
        mandatory true;
        description
          "Number of variable request OAMPDUs transmitted.";
        reference
          "IEEE Std 802.3, 30.3.6.1.28";

      }

      leaf in-variable-request {
        if-feature remote-mib-retrieval-respond;
        type yang:counter64;
        mandatory true;
        description
          "Number of variable request OAMPDUs received.";
        reference
          "IEEE Std 802.3, 30.3.6.1.29";

      }

      leaf out-variable-response {
        if-feature remote-mib-retrieval-respond;
        type yang:counter64;
        mandatory true;
        description
          "Number of variable response OAMPDUs transmitted.";
        reference
          "IEEE Std 802.3, 30.3.6.1.30";

      }

      leaf in-variable-response {
        if-feature remote-data-retrieval-initiate;
        type yang:counter64;
        mandatory true;
        description
          "Number of variable response OAMPDUs received.";
        reference
          "IEEE Std 802.3, 30.3.6.1.31";

      }

      leaf out-org-specific {
        type yang:counter64;
        mandatory true;
        description
          "Number of organization specific OAMPDUs transmitted.";
        reference
          "IEEE Std 802.3, 30.3.6.1.32";

      }

      leaf in-org-specific {
        type yang:counter64;
        mandatory true;
        description
          "Number of organization specific OAMPDUs received.";
        reference
          "IEEE Std 802.3, 30.3.6.1.33";

      }

      leaf out-unsupported-codes {
        type yang:counter64;
        mandatory true;
        description
          "Number of OAMPDUs with unsupported codes transmitted.";
        reference
          "IEEE Std 802.3, 30.3.6.1.18";

      }

      leaf in-unsupported-codes {
        type yang:counter64;
        mandatory true;
        description
          "Number of OAMPDUs with unsupported codes received.";
        reference
          "IEEE Std 802.3, 30.3.6.1.19";

      }

      leaf frames-lost-due-to-oam {
        type yang:counter64;
        mandatory true;
        description
          "A count of the number of frames that were dropped by the
         OAM multiplexer. Since the OAM multiplexer has multiple
         inputs and a single output, there may be cases where
         frames are dropped due to transmit resource contention.
         This counter is incremented whenever a frame is dropped by
         the OAM layer.";
        reference
          "IEEE Std 802.3, 30.3.6.1.46";

      }
    }  // grouping statistics-common

    grouping discovery-remote {
      description
        "Nodes describing the discovery process remote end of a
           link.";
      leaf mode {
        type mode;
        description "Mode (passive/active).";
        reference
          "IEEE Std 802.3, 30.3.6.1.3";

      }

      container functions-supported {
        description
          "The Link OAM functions supported by this interface.";
        reference
          "IEEE Std 802.3, 30.3.6.1.7";

        leaf uni-directional-link-fault {
          type boolean;
          description
            "Unidirectional link fault support.";
        }

        leaf loopback {
          type boolean;
          description
            "Remote Loopback support.";
        }

        leaf link-monitoring {
          type boolean;
          description
            "Link monitoring support.";
        }

        leaf mib-retrieval {
          type boolean;
          description
            "MIB variable retrieval support.";
        }
      }  // container functions-supported

      leaf revision {
        type uint64;
        config false;
        description
          "Configuration revision.";
        reference
          "IEEE Std 802.3, 30.3.6.1.12 and 30.3.6.1.13";

      }

      leaf oammtu {
        type uint16;
        units "octets";
        config false;
        description
          "The maximum OAMPDU size for the remote node.
         The peer OAM entities exchange the maximum size they can
         support and negotiate to use the smaller of the two maximum
         OAMPDU sizes.";
        reference
          "IEEE Std 802.3, 30.3.6.1.8 and 30.3.6.1.9";

      }
    }  // grouping discovery-remote

    grouping discovery-local {
      description
        "Nodes describing the local end discovery process of a
           link.";
      leaf mode {
        type mode;
        description
          "This object configures the mode of OAM operation as active
         or passive. Active mode provides capabilities to initiate
         monitoring activities with the remote OAM peer eneity,
         while passive mode waits for the peer to initiate actions
         with it. Changing this value results in incrementing the
         revision field of locally generated OAMPDUs
         (see IEEE Std 802.3, 30.3.6.1.12) and triggers the
         OAM discovery process if the operational state was
         already 'operational'.  The default value is
         implementation-dependent.";
        reference
          "IEEE Std 802.3, 30.3.6.1.3";

      }

      container functions-supported {
        description
          "The Link OAM functions supported by this interface.";
        reference
          "IEEE Std 802.3, 30.3.6.1.7";

        leaf uni-directional-link-fault {
          if-feature uni-directional-link-fault;
          type boolean;
          description
            "Unidirectional link fault support.
           This affects the setting of the 'Unidirectional Support'
           bit in the OAM configuration field put in the
           Information OAMPDU.
           This bit indicates to the peer device that it can send
           OAM PDUs on links that are operating in unidirectional
           mode (traffic flowing in one direction only).";
        }

        leaf loopback {
          if-feature remote-loopback-initiate;
          type boolean;
          default "true";
          description
            "Remote Loopback support.";
        }

        container link-monitor {
          if-feature link-monitoring-remote or
link-monitoring-local;
          description
            "Configure link monitor parameters.";
          reference
            "IEEE Std 802.3, 57.1.2:c";

          leaf link-monitoring {
            type boolean;
            default "true";
            description
              "Enable or disable monitoring.
             This affects the setting of the 'Link Events' bit in
             the OAM configuration field put in the Information
             OAMPDU. This bit indicates to the peer device that the
             OAM entity can send and receive Event Notification
             OAMPDUs.";
          }

          list event-type {
            if-feature link-monitoring-local;
            key "threshold-type";
            description
              "A list containing at most one entry for each of the
             threshold event types. If there is no entry for a
             particular event type, the default values are used for
             both window size and threshold.";
            leaf threshold-type {
              type threshold-event-enum;
              description
                "The type of threshold event for which this list
               entry is specifying the configuration.";
              reference
                "IEEE Std 802.3, 57.5.3";

            }

            leaf window {
              type uint64;
              description
                "The size of the window to use when monitoring for
               this threshold event. The units, default and upper
               and lower bounds depend on the threshold type as
               follows:

               Symbol Period:
                 Units:   number of symbols
                 Default: number of symbols in one second for the
                          underlying physical layer
                 Min:     number of symbols in one second for the
                          underlying physical layer
                 Max:     number of symbols in one minute for the
                          underlying physical layer

               Frame:
                 Units:   deciseconds
                 Default: 1 second
                 Min:     1 second
                 Max:     1 minute

               Frame Period:
                 Units:   number of frames
                 Default: number of minFrameSize frames in one
                          second for the underlying physical layer
                 Min:     number of minFrameSize frames in one
                          second for the underlying physical layer
                 Max:     number of minFrameSize frames in one
                          minute for the underlying physical layer

               Frame Seconds:
                 Units:   deciseconds
                 Default: 60 seconds
                 Min:     10 seconds
                 Max:     900 seconds";
              reference
                "IEEE Std 802.3, 30.3.6.1.34, 30.3.6.1.36, 30.3.6.1.38,
                and 30.3.6.1.40";

            }

            leaf threshold {
              type uint64 {
                range "1..max";
              }
              default "1";
              description
                "The threshold value to use when determining whether
               to generate an event given the number of errors that
               occurred in a given window. The units depend on the
               threshold type as follows:

               Symbol Period: number of errored symbols
               Frame:         number of errored frames
               Frame Period:  number of errored frames
               Frame Seconds: number of seconds containing at least
               1 frame error";
              reference
                "IEEE Std 802.3, 30.3.6.1.34, 30.3.6.1.36, 30.3.6.1.38,
                and 30.3.6.1.40";

            }
          }  // list event-type
        }  // container link-monitor

        leaf mib-retrieval {
          if-feature remote-mib-retrieval-initiate or
remote-mib-retrieval-respond;
          type boolean;
          status deprecated;
          description
            "leaf mib-retrieval is deprecated and changed name to
           data-retrieval.
           MIB variable retrieval support.
           This affects the setting of the 'Variable Retrieval' bit
           in the OAM configuration field put in the Information
           OAMPDU. This bit indicates to the peer device that the
           OAM entity can send and receive Variable Request and
           Response OAMPDUs.";
        }

        leaf data-retrieval {
          if-feature remote-data-retrieval-initiate or
remote-mib-retrieval-respond;
          type boolean;
          description
            "Variable retrieval support.
           This affects the setting of the 'Variable Retrieval' bit
           in the OAM configuration field put in the Information
           OAMPDU. This bit indicates to the peer device that the
           OAM entity can send and receive Variable Request and
           Response OAMPDUs.";
        }
      }  // container functions-supported

      leaf revision {
        type uint64;
        config false;
        description
          "Configuration revision.";
        reference
          "IEEE Std 802.3, 30.3.6.1.12 and 30.3.6.1.13";

      }

      leaf oammtu {
        type uint16;
        units "octets";
        config false;
        description
          "The maximum OAMPDU size for the local node. The peer OAM
         entities exchange the maximum size they can support and
         negotiate to use the smaller of the two maximum OAMPDU
         sizes.";
        reference
          "IEEE Std 802.3, 30.3.6.1.8 and 30.3.6.1.9";

      }
    }  // grouping discovery-local

    grouping discovery-info {
      description
        "Information relating to the discovery process.";
      container local {
        description
          "Properties of the local device.";
        leaf operational-status {
          type operational-state;
          config false;
          mandatory true;
          description "Operational status.";
          reference
            "IETF RFC 4878, dot3OamOperStatus; IEEE Std 802.3,
            30.3.6.1.4, 30.3.6.1.10, and 30.3.6.1.11";

        }

        leaf loopback-mode {
          if-feature remote-loopback-initiate or
remote-loopback-respond;
          type loopback-status;
          config false;
          mandatory true;
          description
            "The loopback mode the interface is in.";
          reference
            "IEEE Std 802.3, 30.3.6.1.14";

        }

        uses discovery-local;
      }  // container local

      container remote {
        config false;
        description
          "Properties of the remote (peer) device.";
        leaf mac-address {
          type ieee:mac-address;
          description "Remote MAC address.";
          reference
            "IEEE Std 802.3, 30.3.6.1.5";

        }

        leaf vendor-oui {
          type vendor-oui;
          description "Remote vendor OUI.";
          reference
            "IEEE Std 802.3, 30.3.6.1.16";

        }

        leaf vendor-info {
          type uint64;
          description
            "Remote vendor info. The semantics of this value are
           proprietary and specific to the vendor.";
          reference
            "IEEE Std 802.3, 30.3.6.1.17";

        }

        leaf loopback-mode {
          type loopback-status;
          mandatory true;
          description
            "The loopback mode the interface is in.";
          reference
            "IEEE Std 802.3, 30.3.6.1.15";

        }

        uses discovery-remote;
      }  // container remote
    }  // grouping discovery-info

    augment /if:interfaces/if:interface {
      when
        "derived-from-or-self(if:type, 'ianaift:ethernetCsmacd') or
          derived-from-or-self(if:type, 'ianaift:ptm') " {
        description
          "Augments the interface model with nodes
         specific to Ethernet Link OAM.";
      }
      description
        "Augments Ethernet interface model with nodes
       specific to Ethernet Link OAM.";
      container link-oam {
        presence
          "Implies Link OAM is configured on the interface.";
        description
          "Interface operational state for Ethernet Link OAM.";
        action remote-loopback {
          if-feature remote-loopback-initiate;
          description
            "Start/stop remote loopback on the specified interface.";
          reference
            "IEEE Std 802.3, 57.1.2:b";

          input {
            leaf enable {
              type boolean;
              mandatory true;
              description
                "Whether to enable or disable remote loopback.";
            }
          }

          output {
            leaf success {
              type boolean;
              mandatory true;
              description
                "True if the operation was successful,
               false otherwise.";
            }

            leaf error-message {
              type string;
              description
                "If the operation failed, optionally used to
               provide extra details.";
            }
          }
        }  // rpc remote-loopback

        action reset-stats {
          description
            "Reset Ethernet Link OAM statistics on this interface.";
          output {
            leaf success {
              type boolean;
              mandatory true;
              description
                "True if the operation was successful,
               false otherwise.";
            }

            leaf error-message {
              type string;
              description
                "If the operation failed, optionally used to provide
               extra details.";
            }
          }
        }  // rpc reset-stats

        notification non-threshold-event {
          description
            "This notification is sent when a local or remote
           non-threshold crossing event is detected.";
          uses event-details {
            refine event-type {
              must
                ". != 'ieee802-link-oam:threshold-event-type'" {
                description
                  "This leaf is not set to
                 'threshold-event-type'.";
              }
            }
          }
        }  // notification non-threshold-event

        notification threshold-event {
          if-feature link-monitoring-local or
link-monitoring-remote;
          description
            "This notification is sent when a local or remote
           threshold crossing event is detected.";
          uses event-details {
            refine event-type {
              must
                ". = 'ieee802-link-oam:threshold-event-type'" {
                description
                  "This leaf is set to 'threshold-event-type'.";
              }
            }
          }

          uses threshold-event-details;
        }  // notification threshold-event

        leaf admin {
          type admin-state;
          default "disabled";
          description
            "This object is used to provision the default
           administrative OAM mode for this interface. This object
           represents the desired state of OAM for this interface.
           It starts in the disabled state until an explicit
           management action or configuration information retained
           by the system causes a transition to the enabled(1)
           state. When enabled(1), Ethernet OAM will attempt to
           operate over this interface. The default value is
           implementation-dependent.";
        }

        container discovery-info {
          description
            "Information relating to the discovery process.";
          uses discovery-info;
        }  // container discovery-info

        container event-log {
          config false;
          description
            "List of Ethernet Link OAM event log entries on the
           interface.";
          list event-log-entry {
            key "index";
            description
              "Ethernet Link OAM event log entry.";
            leaf index {
              type uint64;
              description
                "Index of this event in the event log.";
            }

            uses event-details;

            uses threshold-event-details;
          }  // list event-log-entry
        }  // container event-log

        container statistics {
          config false;
          description
            "Statistics for an 802.3 OAM interface.";
          uses statistics-common;

          leaf local-error-symbol-period-log-entries {
            type yang:counter64;
            mandatory true;
            description
              "Number of local error symbol period log entries.";
          }

          leaf local-error-frame-log-entries {
            type yang:counter64;
            mandatory true;
            description
              "Number of local error frame log entries.";
          }

          leaf local-error-frame-period-log-entries {
            type yang:counter64;
            mandatory true;
            description
              "Number of local error frame period log entries.";
          }

          leaf local-error-frame-second-log-entries {
            type yang:counter64;
            mandatory true;
            description
              "Number of local error frame second log entries.";
          }

          leaf remote-error-symbol-period-log-entries {
            if-feature link-monitoring-remote;
            type yang:counter64;
            mandatory true;
            description
              "Number of remote error symbol period log entries.";
          }

          leaf remote-error-frame-log-entries {
            if-feature link-monitoring-remote;
            type yang:counter64;
            mandatory true;
            description
              "Number of remote error frame log entries.";
          }

          leaf remote-error-frame-period-log-entries {
            if-feature link-monitoring-remote;
            type yang:counter64;
            mandatory true;
            description
              "Number of remote error frame period log entries.";
          }

          leaf remote-error-frame-second-log-entries {
            if-feature link-monitoring-remote;
            type yang:counter64;
            mandatory true;
            description
              "Number of remote error frame second log entries.";
          }
        }  // container statistics
      }  // container link-oam
    }
  }  // module ieee802-ethernet-link-oam