module ieee802-ethernet-interface-half-duplex {

    yang-version 1.1;

    namespace
      "urn:ieee:std:802.3:yang:ieee802-ethernet-interface-half-duplex";

    prefix ieee802-eth-half-duplex;

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


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


    }
    import iana-if-type {
      prefix ianaift;
      reference
        "http://www.iana.org/assignments/yang-parameters/
        iana-if-type@2018-07-03.yang";


    }
    import ieee802-ethernet-interface {
      prefix ieee802-eth-if;
    }

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

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

    description
      "This module contains YANG definitions for configuring Ethernet 
     interfaces that are deprecated, and are no longer
     widely used in the industry. The definitions are maintained for
     backwards compatibility purposes, but the general expectation is
     that this module is not anticipated to be widely implemented.";

    revision "2019-06-21" {
      description "Initial revision.";
      reference
        "IEEE Std 802.3-2018, unless dated explicitly";

    }


    feature dynamic-rate-control {
      description
        "This feature indicates that the device supports Ethernet
       interfaces lowering the average data rate of the MAC sublayer,
       with frame granularity, by using Rate Control to dynamically
       increase the inter-packet gap for some types of Ethernet
       interface.
       Only valid for Ethernet interfaces operating at speeds (data rates)
       above 1000 Mb/s.";
      reference
        "IEEE Std 802.3, 30.3.1.1.33 aRateControlAbility";

    }

    feature csma-cd {
      description
        "This feature indicates that the device supports Ethernet
       interfaces running at half-duplex using CSMA/CD.";
    }

    typedef dynamic-rate-control-type {
      type enumeration {
        enum "disabled" {
          value 0;
          description
            "Dynamic rate control is disabled";
        }
        enum "sonet-oc192" {
          value 2;
          description
            "Dynamic rate control is enabled for a 10 Gb/s Ethernet
           interface to SONET/SDH OC192/STM64.";
        }
      }
      default 'disabled';
      description
        "Allowed values for dynamic-rate-control.";
      reference
        "IEEE Std 802.3, 4.4.2 ipgStretchRatio and 30.3.1.1.34
        aRateControlStatus";

    }

    augment /if:interfaces/if:interface/ieee802-eth-if:ethernet {
      when
        "derived-from-or-self(../if:type, 'ianaift:ethernetCsmacd') 
      and ieee802-eth-if:duplex = 'half'" {
        description
          "Applies to half-duplex Ethernet interfaces.";
      }
      description
        "Augment with Ethernet interface configuration parameters 
       for half-duplex operation.";
      leaf dynamic-rate-control {
        if-feature dynamic-rate-control;
        type dynamic-rate-control-type;
        description
          "Enables dynamic rate control and specifies what speed (data rate) 
         the dynamic rate control is operating at. The value of this attribute
         is constrained by the MAC data rate and hardware support.
         The default value is implementation-dependent.";
        reference
          "IEEE Std 802.3, 30.3.1.1.34 aRateControlStatus";

      }
    }

    augment /if:interfaces/if:interface/ieee802-eth-if:ethernet/ieee802-eth-if:capabilities {
      when
        "derived-from-or-self(../../if:type, 
       'ianaift:ethernetCsmacd') and ../ieee802-eth-if:duplex = 'half'" {
        description
          "Applies to half-duplex Ethernet interfaces";
      }
      description
        "Augment with configuration capabilities for half-duplex 
       Ethernet interface.";
      leaf dynamic-rate-control-supported {
        if-feature dynamic-rate-control;
        type boolean;
        default 'false';
        description
          "Indicates whether the Ethernet interface supports lowering
         the average data rate of the MAC sublayer, with frame
         granularity, by using Rate Control to dynamically increase
         the inter-packet gap.
         Only valid for Ethernet interfaces operating at speeds (data rates)
         above 1000 Mb/s.";
        reference
          "IEEE Std 802.3, 30.3.1.1.33 aRateControlAbility";

      }
    }

    augment /if:interfaces/if:interface/ieee802-eth-if:ethernet/ieee802-eth-if:statistics/ieee802-eth-if:frame {
      when
        "derived-from-or-self(../../../if:type, 
      'ianaift:ethernetCsmacd') and ../../ieee802-eth-if:duplex = 'half'" {
        description
          "Applies to half-duplex Ethernet interfaces.";
      }
      description
        "Augment with statistics for half-duplex Ethernet interface.";
      container csma-cd {
        if-feature csma-cd;
        description
          "Holds counters that are specific to CDMA/CD half-duplex
         operation of Ethernet interfaces.
         Discontinuities in the values of the counters in this
         container can occur at re-initialization of the management
         system, and at other times as indicated by the value of the
         'discontinuity-time' leaf defined in the ietf-interfaces
         YANG module (IETF RFC 8343).";
        leaf in-errors-sqe-test {
          type yang:counter64;
          units "errors";
          description
            "A count of times that the SQE TEST ERROR is received on a
           particular interface. The SQE TEST ERROR is set in
           accordance with the rules for verification of the SQE
           detection mechanism in the PLS Carrier Sense Function as
           described in IEEE Std 802.3, 7.2.4.6.
           This counter does not increment on Ethernet interfaces
           operating at speeds (data rates) greater than 10 Mb/s, or on 
           Ethernet interfaces operating in full-duplex mode.
           Discontinuities in the value of this counter can occur at
           re-initialization of the management system, and at other
           times as indicated by the value of the
           'discontinuity-time' leaf defined in the ietf-interfaces
           YANG module (IETF RFC 8343).";
          reference
            "IEEE Std 802.3, 7.2.4.6, and 30.3.2.1.4 aSQETestErrors";

        }

        leaf out-frames-collision-single {
          type yang:counter64;
          units "frames";
          description
            "A count of frames that are involved in a single collision,
           and are subsequently transmitted successfully. A frame
           that is counted by an instance of this object is also
           counted by the corresponding instance of either
           'out-unicast-frames', 'out-broadcast-frames', or
           'out-multicast-frames', and is not counted by the
           corresponding instance of the
           'out-frames-collision-multiple'.

           This counter does not increment when the Ethernet
           interface is operating in full-duplex mode.
           Discontinuities in the value of this counter can occur at
           re-initialization of the management system, and at other
           times as indicated by the value of the
           'discontinuity-time' leaf defined in the ietf-interfaces
           YANG module (IETF RFC 8343).";
          reference
            "IEEE Std 802.3, 30.3.1.1.3 aSingleCollisionFrames";

        }

        leaf out-frames-collision-multiple {
          type yang:counter64;
          units "frames";
          description
            "A count of frames that are involved in multiple
           collisions, and are subsequently transmitted
           successfully. A frame that is counted by an instance of
           this object is also counted by the corresponding instance
           of either 'out-unicast-frames', 'out-broadcast-frames', or
           'out-multicast-frames', and is not counted by the
           corresponding instance of the 'out-frames-collision-single'.
           This counter does not increment when the Ethernet
           interface is operating in full-duplex mode.
           Discontinuities in the value of this counter can occur at
           re-initialization of the management system, and at other
           times as indicated by the value of the
           'discontinuity-time' leaf defined in the ietf-interfaces
           YANG module (IETF RFC 8343).";
          reference
            "IEEE Std 802.3, 30.3.1.1.4 aMultipleCollisionFrames";

        }

        leaf out-frames-deferred {
          type yang:counter64;
          units "frames";
          description
            "A count of frames for which the first transmission attempt
           on a particular Ethernet interface is delayed because the
           medium is busy.
           A deferred frame that is not subject to any number of
           collisions is not counted by an instance of
           'out-frames-collision-single' or
           'out-frames-collision-multiple' objects.
           This counter does not increment when the Ethernet
           interface is operating in full-duplex mode.
           Discontinuities in the value of this counter can occur at
           re-initialization of the management system, and at other
           times as indicated by the value of the
           'discontinuity-time' leaf defined in the ietf-interfaces
           YANG module (IETF RFC 8343).";
          reference
            "IEEE Std 802.3, 30.3.1.1.9 aFramesWithDeferredXmissions";

        }

        leaf out-frames-collisions-excessive {
          type yang:counter64;
          units "frames";
          description
            "A count of frames for which transmission on a particular
           Ethernet interface fails due to excessive collisions.

           This counter does not increment when the Ethernet
           interface is operating in full-duplex mode.
           Discontinuities in the value of this counter can occur at
           re-initialization of the management system, and at other
           times as indicated by the value of the
           'discontinuity-time' leaf defined in the ietf-interfaces
           YANG module (IETF RFC 8343).";
          reference
            "IEEE Std 802.3, 30.3.1.1.11 aFramesAbortedDueToXSColls";

        }

        leaf out-collisions-late {
          type yang:counter64;
          units "collisions";
          description
            "The number of times that a collision is detected on a
           particular Ethernet interface later than one slotTime into
           the transmission of a packet.
           A (late) collision included in a count represented by an
           instance of this object is also considered as a (generic)
           collision for purposes of other collision-related
           statistics.
           This counter does not increment when the Ethernet
           interface is operating in full-duplex mode.
           Discontinuities in the value of this counter can occur at
           re-initialization of the management system, and at other
           times as indicated by the value of the
           'discontinuity-time' leaf defined in the ietf-interfaces
           YANG module (IETF RFC 8343).";
          reference
            "IEEE Std 802.3, 30.3.1.1.10 aLateCollisions";

        }

        leaf out-errors-carrier-sense {
          type yang:counter64;
          units "errors";
          description
            "The number of times that the carrier sense condition was
           lost or never asserted when attempting to transmit a frame
           on a particular Ethernet interface.
           The count represented by an instance of this object is
           incremented at most once per transmission attempt, even if
           the carrier sense condition fluctuates during a
           transmission attempt.
           This counter does not increment when the Ethernet
           interface is operating in full-duplex mode.
           Discontinuities in the value of this counter can occur at
           re-initialization of the management system, and at other
           times as indicated by the value of the
           'discontinuity-time' leaf defined in the ietf-interfaces
           YANG module (IETF RFC 8343).";
          reference
            "IEEE Std 802.3, 30.3.1.1.13 aCarrierSenseErrors";

        }

        list collision-histogram {
          key "collision-count";
          description
            "A collection of collision histograms for a particular
           interface.";
          reference
            "IEEE Std 802.3, 30.3.1.1.30 aCollisionFrames";

          leaf collision-count {
            type yang:counter64;
            units "collisions";
            description
              "The number of per-frame media collisions for which a
             particular collision histogram cell represents the
             frequency on a particular interface.";
          }

          leaf collision-count-frames {
            type yang:counter64;
            units "frames";
            description
              "A count of individual MAC frames for which the
             transmission (successful or otherwise) on a particular
             interface occurs after the frame has experienced exactly
             the number of collisions in the associated dot3CollCount
             object.
             For example, a frame which is transmitted on an
             interface after experiencing exactly 4 collisions would
             be indicated by incrementing only collision-count-frames
             object associated with the collision-count value of
             4. No other instance of collision-count-frames would be
             incremented in this example.
             This counter does not increment when the interface is
             operating in full-duplex mode.
             Discontinuities in the value of this counter can occur
             at re-initialization of the management system, and at
             other times as indicated by the value of the
             'discontinuity-time' leaf defined in the ietf-interfaces
             YANG module (IETF RFC 8343).";
          }
        }  // list collision-histogram
      }  // container csma-cd
    }
  }  // module ieee802-ethernet-interface-half-duplex