module openconfig-qos-types {

    yang-version 1;

    namespace
      "http://openconfig.net/yang/qos-types";

    prefix oc-qos-types;

    import openconfig-extensions {
      prefix oc-ext;
    }

    organization "OpenConfig working group";

    contact
      "OpenConfig working group
www.openconfig.net";

    description
      "This module defines types and identities used in OpenConfig
models related to quality-of-service (QoS)";

    revision "2018-11-21" {
      description
        "Add OpenConfig module metadata extensions.";
      reference
        "0.2.1";

    }

    revision "2016-12-16" {
      description
        "Fix incorrect interface-ref placement";
      reference
        "0.2.0";

    }

    revision "2016-08-08" {
      description "Initial revision";
      reference
        "0.1.0";

    }

    oc-ext:openconfig-version "0.2.1";
    oc-ext:regexp-posix;
    oc-ext:catalog-organization "openconfig";
    oc-ext:origin "openconfig";

    identity QOS_QUEUE_TYPE {
      description
        "Base identity for supported queue types, primarily
defined by their drop behavior / strategy";
    }

    identity DROP_TAIL {
      base QOS_QUEUE_TYPE;
      description
        "When the queue is filled to capacity, newly arriving packets
are discarded until there is room in the queue to accept new
traffic.  Packets are not differentiated, i.e., all packets
are treated identically.";
    }

    identity RED {
      base QOS_QUEUE_TYPE;
      description
        "Queue management based on Random Early Detection (RED).  RED
drops packets based on a drop probability that is based on the
average queue length, and settings of mininum and maximum
queue thresholds.  On ECN-capable devices, packets may be
marked instead of dropped to signal congestion to the
sender.";
      reference
        "IETF RFC 2309 - Recommendations on Queue Management and
        Congestion Avoidance in the Internet
        IETF RFC 7567 - IETF Recommendations Regarding Active Queue
        Management";

    }

    identity WRED {
      base QOS_QUEUE_TYPE;
      description
        "Queue management based on a variant of RED in which the packet
drop probability is based on its traffic class.";
    }

    identity QOS_SCHEDULER_TYPE {
      description
        "Base identity to describe supported QoS scheduler types.";
    }

    identity ONE_RATE_TWO_COLOR {
      base QOS_SCHEDULER_TYPE;
      description
        "Token bucket scheduler with a single rate (committed information
rate) and two colors (conforming and exceeding).  The scheduler
behavior is governed by two parameters, the CIR which
determines the rate of token fill (bps) and the committed
burst size (depth of the token bucket in bytes).";
    }

    identity TWO_RATE_THREE_COLOR {
      base QOS_SCHEDULER_TYPE;
      description
        "Token bucket scheduler with two buckets, one filled at the
committed information rate (CIR) in bps, and the second filled
at the peak information rate (PIR) in bps when the first
bucket is full.  The first bucket depth is
the committed burst size (bytes), and the second is the
excess burst size (bytes).  Traffic is categorized in three
colors as follows: traffic that falls within the
the CIR is conforming, traffic that is greater than the CIR
but less than the PIR is exceeding, and traffic that is
greater than PIR is violating.";
    }

    typedef queue-behavior {
      type enumeration {
        enum "SHAPE" {
          value 0;
          description
            "Packets that exceed the CIR should be queued into a
buffer. The depth of the buffer is specified to be
max-queue-depth-bytes or max-queue-depth-packets.
Packets are subsequently scheduled from this queue
to the specified output. Only packets that overflow
the buffer have the exceed action applied to them.";
        }
        enum "POLICE" {
          value 1;
          description
            "Packets that exceed the CIR should be immediately
treated as exceeding the defined rate of the scheduler
and have the exceed action applied to them.";
        }
      }
      description
        "Type definition for different queueing behaviours that
are available to a scheduler.";
    }
  }  // module openconfig-qos-types