module bbf-qos-enhanced-scheduling {

    yang-version 1.1;

    namespace
      "urn:bbf:yang:bbf-qos-enhanced-scheduling";

    prefix bbf-qos-sched;

    import bbf-yang-types {
      prefix bbf-yang;
    }
    import ietf-interfaces {
      prefix if;
    }
    import bbf-if-type {
      prefix bbfift;
    }
    import bbf-qos-traffic-mngt {
      prefix bbf-qos-tm;
    }
    import bbf-qos-shaping {
      prefix bbf-qos-shap;
    }

    organization
      "Broadband Forum <https://www.broadband-forum.org>
     Common YANG Work Area";

    contact
      "Comments or questions about this Broadband Forum YANG module
     should be directed to <mailto:help@broadband-forum.org>.

     Editor:      Joey Boyd, ADTRAN

     Editor:      Ludwig Pauwels, Nokia

     PS Leader:   Joey Boyd, ADTRAN

     PS Leader:   Ken Kerpez, ASSIA

     WA Director: Joey Boyd, ADTRAN

     WA Director: Sven Ooghe, Nokia";

    description
      "This module contains a collection of YANG definitions for 
     supporting the Broadband Forum requirements on the management of
     Quality of Service (QoS) as applicable to access network 
     equipment. As such, this module is specific to access network 
     equipment (e.g., BBF-specified Access Nodes and FTTdp DPUs).

     Specifically, this module contains a collection of enhanced 
     traffic scheduling configuration.

     Copyright (c) 2017-2018, Broadband Forum

     Redistribution and use in source and binary forms, with or
     without modification, are permitted provided that the following
     conditions are met:

     1. Redistributions of source code must retain the above copyright
        notice, this list of conditions and the following disclaimer.

     2. Redistributions in binary form must reproduce the above
        copyright notice, this list of conditions and the following
        disclaimer in the documentation and/or other materials
        provided with the distribution.

     3. Neither the name of the copyright holder nor the names of its
        contributors may be used to endorse or promote products
        derived from this software without specific prior written
        permission.

     THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
     CONTRIBUTORS \"AS IS\" AND ANY EXPRESS OR IMPLIED WARRANTIES,
     INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
     MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
     DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR
     CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
     SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
     NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
     LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
     CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
     STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
     ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

     The above license is used as a license under copyright only.
     Please reference the Forum IPR Policy for patent licensing terms
     <https://www.broadband-forum.org/ipr-policy>.

     Any moral rights which are necessary to exercise under the above
     license grant are also deemed granted under this license.

     This version of this YANG module is part of TR-383; see
     the TR itself for full legal notices.";

    revision "2018-07-13" {
      description
        "Initial revision.
       * Approval Date:    2018-06-04.
       * Publication Date: see revision date above.";
      reference
        "TR-383: Common YANG Modules
        	<https://www.broadband-forum.org/technical/download/
        		 TR-383_Amendment-1.pdf>";

    }


    grouping child-scheduling {
      description
        "A grouping that models the method to schedule from child 
       schedulers.";
      choice scheduling-type {
        description
          "Defines the child node's type of a scheduling node in 
         case of hierachical scheduling.";
        case inline {
          uses bbf-qos-tm:scheduling-gen-attr;
        }  // case inline
      }  // choice scheduling-type
    }  // grouping child-scheduling

    augment /if:interfaces/if:interface/bbf-qos-tm:tm-root/bbf-qos-tm:children-type {
      description
        "Extends the traffic management root with a possibility to have 
       a scheduling hierarchy.";
      case scheduler-node {
        description
          "The data to manage a scheduling hierarchy. A scheduling 
         hierarchy starts with schedulers and ends with schedulers 
         that contain queues. The schedulers are organized as a flat 
         list where the hierarchy is managed through references from 
         'parent' schedulers to 'child' schedulers.";
        list scheduler-node {
          key "name";
          description
            "A list of schedulers. A scheduler will be at a position in 
           a hierarchy as specified through references. A particular 
           scheduler will get its input from its childs from which it 
           merges the traffic into a single output stream. This output
           can be shaped if a reference to a shaper-profile is 
           configured.";
          leaf name {
            type bbf-yang:string-ascii64;
            description
              "A name of scheduler-node.";
          }

          leaf description {
            type bbf-yang:string-ascii64;
            description
              "A free format description assigned to this scheduler.
             It can be used to identify the purpose of the
             scheduler instance in the hierarchy. For example, the
             description could be the name of an interface in the 
             hierarchy of an interface stack.";
          }

          leaf scheduling-level {
            type uint8;
            mandatory true;
            description
              "The level of a scheduler helps in organizing a hierarchy.
             The requirement is that the scheduling level of a parent 
             must be lower than the scheduling-level of its referenced
             children.";
          }

          uses bbf-qos-shap:shaper-profile-ref;

          choice children-type {
            description
              "Defines the child's node type of a scheduling node in 
             case of hierachical scheduling.";
            case scheduler-node {
              description
                "The children are a list of scheduler-nodes.";
              list child-scheduler-nodes {
                key "name";
                description
                  "Provides a child scheduler nodes list and related 
                 scheduling data.";
                leaf name {
                  type leafref {
                    path
                      '../../bbf-qos-sched:name';
                  }
                  must
                    "../../../bbf-qos-sched:scheduler-node
                   [bbf-qos-sched:name=current()]
                   /scheduling-level>
                   current()/../../scheduling-level" {
                    error-message
                      "The scheduler-level should be bigger than the 
                     value of parent node.";
                  }
                  description
                    "The name of the referenced scheduling-nodes entry.
                   The child scheduler nodes must locate on the same 
                   Traffic Management (TM) root with the parent 
                   scheduler node. 

                   The scheduling level of the child scheduler node
                   must be higher than the scheduling level of the 
                   parent scheduler node.";
                }

                uses child-scheduling;
              }  // list child-scheduler-nodes
            }  // case scheduler-node

            case queue {
              description
                "The children are a list of queues.";
              leaf contains-queues {
                type boolean;
                default "true";
                description
                  "Indicates the scheduler contains queues.";
              }

              uses bbf-qos-tm:queues;
            }  // case queue
          }  // choice children-type
        }  // list scheduler-node

        list child-scheduler-nodes {
          key "name";
          description
            "Provides the list of direct child scheduler nodes of the 
           traffic management root.";
          leaf name {
            type leafref {
              path
                '../../bbf-qos-sched:scheduler-node/bbf-qos-sched:'
                  + 'name';
            }
            description
              "The first set of schedulers that are scheduled from the 
             traffic management root.";
          }

          uses child-scheduling;
        }  // list child-scheduler-nodes
      }  // case scheduler-node
    }

    augment /if:interfaces/if:interface/bbf-qos-tm:tm-root/bbf-qos-tm:children-type/bbf-qos-sched:scheduler-node/bbf-qos-sched:scheduler-node/bbf-qos-sched:children-type/bbf-qos-sched:queue/bbf-qos-sched:queue/bbf-qos-sched:queue-scheduling-cfg-type/bbf-qos-sched:inline {
      description
        "Augment a queue defined within a scheduler with extra data.";
      uses bbf-qos-shap:shaper-profile-ref;
    }

    grouping scheduler-containing-queues-ref {
      description
        "An absolute reference to a scheduling node.";
      leaf root-if-name {
        type leafref {
          path "/if:interfaces/if:interface/if:name";
        }
        description
          "The name of the referenced interface that is the traffic 
         management root of a scheduling hierarchy. This interface 
         must be a lower layer interface of the interface that 
         contains the reference to it. However, due to interface 
         stacking it is not necessarily the adjacent lower layer 
         interface.";
      }

      leaf scheduler-node-name {
        type leafref {
          path "/if:interfaces/if:interface[if:name = current()/../root-if-name]/bbf-qos-tm:tm-root/bbf-qos-sched:scheduler-node/bbf-qos-sched:name";
        }
        must
          "/if:interfaces/if:interface[if:name =
         current()/../root-if-name]/bbf-qos-tm:tm-root
         /bbf-qos-sched:scheduler-node
         [bbf-qos-sched:name=current()]
         /bbf-qos-sched:contains-queues = 'true'" {
          error-message
            "The referenced scheduler must contain queues.";
        }
        description
          "The name of the referenced scheduling-nodes entry.";
      }
    }  // grouping scheduler-containing-queues-ref

    augment /if:interfaces/if:interface {
      when
        "derived-from-or-self(if:type, 
       'bbfift:vlan-sub-interface')" {
        description
          "Augments a VLAN sub-interface.";
      }
      description
        "Augments a VLAN sub-interface with configuration that links it 
       to traffic management configuration.";
      container egress-tm-objects {
        description
          "Defines the traffic management node(s), to which the 
         egress traffic of the interface shall be directed to.";
        choice select-tm-objects-method {
          description
            "Choice of a type of traffic management node.";
          case scheduler {
            description
              "The traffic will be directed to a single scheduler. This 
             scheduler must contain queues. The queue selection for a 
             packet is based on a tc-id-2-queue-id-mapping-profile.";
            uses scheduler-containing-queues-ref;
          }  // case scheduler
        }  // choice select-tm-objects-method
      }  // container egress-tm-objects
    }
  }  // module bbf-qos-enhanced-scheduling