[Search] [txt|html|xml|pdf|bibtex] [Tracker] [WG] [Email] [Diff1] [Diff2] [Nits]

Versions: 00 01 02 03 04 05                                             
MBONED WG                                                       Z. Zhang
Internet-Draft                                           ZTE Corporation
Intended status: Standards Track                                 C. Wang
Expires: 26 February 2022                                     Individual
                                                                Y. Cheng
                                                            China Unicom
                                                                  X. Liu
                                                          Volta Networks
                                                            M. Sivakumar
                                                        Juniper networks
                                                          25 August 2021


                       Multicast YANG Data Model
               draft-ietf-mboned-multicast-yang-model-05

Abstract

   This document provides a general multicast YANG data model, which
   takes full advantages of existed multicast protocol models to control
   the multicast network, and guides the deployment of multicast
   service.

Status of This Memo

   This Internet-Draft is submitted in full conformance with the
   provisions of BCP 78 and BCP 79.

   Internet-Drafts are working documents of the Internet Engineering
   Task Force (IETF).  Note that other groups may also distribute
   working documents as Internet-Drafts.  The list of current Internet-
   Drafts is at https://datatracker.ietf.org/drafts/current/.

   Internet-Drafts are draft documents valid for a maximum of six months
   and may be updated, replaced, or obsoleted by other documents at any
   time.  It is inappropriate to use Internet-Drafts as reference
   material or to cite them other than as "work in progress."

   This Internet-Draft will expire on 26 February 2022.

Copyright Notice

   Copyright (c) 2021 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

   This document is subject to BCP 78 and the IETF Trust's Legal
   Provisions Relating to IETF Documents (https://trustee.ietf.org/
   license-info) in effect on the date of publication of this document.



Zhang, et al.           Expires 26 February 2022                [Page 1]


Internet-Draft          Multicast YANG Data Model            August 2021


   Please review these documents carefully, as they describe your rights
   and restrictions with respect to this document.  Code Components
   extracted from this document must include Simplified BSD License text
   as described in Section 4.e of the Trust Legal Provisions and are
   provided without warranty as described in the Simplified BSD License.

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
     1.1.  Terminology . . . . . . . . . . . . . . . . . . . . . . .   3
     1.2.  Conventions Used in This Document . . . . . . . . . . . .   4
     1.3.  Tree Diagrams . . . . . . . . . . . . . . . . . . . . . .   4
     1.4.  Prefixes in Data Node Names . . . . . . . . . . . . . . .   4
     1.5.  Usage of Multicast Model  . . . . . . . . . . . . . . . .   5
       1.5.1.  Example . . . . . . . . . . . . . . . . . . . . . . .   7
   2.  Design of the multicast model . . . . . . . . . . . . . . . .   8
     2.1.  Scope of Model  . . . . . . . . . . . . . . . . . . . . .   8
     2.2.  Specification . . . . . . . . . . . . . . . . . . . . . .   8
   3.  Module Structure  . . . . . . . . . . . . . . . . . . . . . .   8
     3.1.  UML like Class Diagram for Multicast YANG data Model  . .   8
     3.2.  Model Structure . . . . . . . . . . . . . . . . . . . . .  10
     3.3.  Multicast YANG data model Configuration . . . . . . . . .  12
     3.4.  Multicast YANG data model State . . . . . . . . . . . . .  13
     3.5.  Multicast YANG data model Notification  . . . . . . . . .  13
   4.  Multicast YANG data Model . . . . . . . . . . . . . . . . . .  14
   5.  Security Considerations . . . . . . . . . . . . . . . . . . .  33
   6.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .  34
   7.  Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .  34
   8.  References  . . . . . . . . . . . . . . . . . . . . . . . . .  34
     8.1.  Normative References  . . . . . . . . . . . . . . . . . .  34
     8.2.  Informative References  . . . . . . . . . . . . . . . . .  37
   Appendix A.  Data Tree Example  . . . . . . . . . . . . . . . . .  40
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  41

1.  Introduction

   Currently, there are many multicast protocol YANG models, such as
   PIM, MLD, and BIER and so on.  But all these models are distributed
   in different working groups as separate files and focus on the
   protocol itself.  Furthermore, they cannot describe a high-level
   multicast service required by network operators.

   This document provides a general and all-round multicast model, which
   stands at a high level to take full advantages of these
   aforementioned models to control the multicast network, and guide the
   deployment of multicast service.





Zhang, et al.           Expires 26 February 2022                [Page 2]


Internet-Draft          Multicast YANG Data Model            August 2021


   This document does not define any specific protocol model, instead,
   it depends on many existing multicast protocol models and relates
   several multicast information together to fulfill multicast service.

   This model can be used along with other multicast YANG models such as
   PIM [I-D.ietf-pim-yang], which are not covered in this document.

1.1.  Terminology

   The terminology for describing YANG data models is found in [RFC6020]
   and [RFC7950], including:

   *  augment

   *  data model

   *  data node

   *  identity

   *  module

   The following abbreviations are used in this document and the defined
   model:

   BABEL: [RFC8966].

   BGP: Border Gateway Protocol [RFC4271].

   BIER: Bit Index Explicit Replication [RFC8279].

   BIER-TE: Traffic Engineering for Bit Index Explicit Replication
   [I-D.ietf-bier-te-arch].

   ISIS: Intermediate System to Intermediate System Routeing Exchange
   Protocol [RFC1195].

   MLD: Multicast Listener Discovery [I-D.ietf-bier-mld].

   MLDP: Label Distribution Protocol Extensions for Point-to-Multipoint
   and Multipoint-to-Multipoint Label Switched Paths [RFC6388].

   MVPN: Multicast in MPLS/BGP IP VPNs [RFC6513].

   OSPF: Open Shortest Path First [RFC2328].

   P2MP-TE: Point-to-Multipoint Traffic Engineering [RFC4875].




Zhang, et al.           Expires 26 February 2022                [Page 3]


Internet-Draft          Multicast YANG Data Model            August 2021


   PIM: Protocol Independent Multicast [RFC7761].

   SR-P2MP: Segment Routing Point-to-Multipoint
   [I-D.ietf-pim-sr-p2mp-policy].

1.2.  Conventions Used in This Document

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
   "OPTIONAL" in this document are to be interpreted as described in BCP
   14 [RFC2119] [RFC8174] when, and only when, they appear in all
   capitals, as shown here.

1.3.  Tree Diagrams

   Tree diagrams used in this document follow the notation defined in
   [RFC8340].

1.4.  Prefixes in Data Node Names

   In this document, names of data nodes, actions, and other data model
   objects are often used without a prefix, as long as it is clear from
   the context in which YANG module each name is defined.  Otherwise,
   names are prefixed using the standard prefix associated with the
   corresponding YANG module, as shown in Table 1.

     +==========+====================+===============================+
     | Prefix   | YANG module        | Reference                     |
     +==========+====================+===============================+
     | inet     | ietf-inet-types    | [RFC6991]                     |
     +----------+--------------------+-------------------------------+
     | isis     | ietf-isis          | [I-D.ietf-isis-yang-isis-cfg] |
     +----------+--------------------+-------------------------------+
     | ospf     | ietf-ospf          | [I-D.ietf-ospf-yang]          |
     +----------+--------------------+-------------------------------+
     | rt-types | ietf-routing-types | [RFC8294]                     |
     +----------+--------------------+-------------------------------+
     | rt       | ietf-routing       | [RFC8349]                     |
     +----------+--------------------+-------------------------------+
     | yang     | ietf-yang-types    | [RFC6991]                     |
     +----------+--------------------+-------------------------------+

                                  Table 1








Zhang, et al.           Expires 26 February 2022                [Page 4]


Internet-Draft          Multicast YANG Data Model            August 2021


1.5.  Usage of Multicast Model

   This multicast YANG data model is mainly used by the management tools
   run by the network operators, in order to manage, monitor and debug
   the network resources that are used to deliver multicast service.
   This model is used for gathering data from the network as well.



                  +------------------------+
                  |    Multicast Model     |
                  +------------------------+
                    |        |          |
                    |        |          |
                    |  +---------+  +----------+
                    |  | EMS/NMS |  |Controller|
                    |  +---------+  +----------+
                    |        |          |
                    |        |          |
           +------------------------------------------------+
           |               Network Element1.....N           |
           +------------------------------------------------+


                     Figure 1: Usage of Multicast Model

   Figure 1 illustrates example use cases for this multicast model.
   Network operators can use this model in a controller which is
   responsible to implement specific multicast flows with specific
   protocols and work with the corresponding protocols' model to
   configure the network elements through NETCONF/RESTCONF/CLI.  Or
   network operators can use this model to the EMS (Element Management
   System)/ NMS (Network Management System) to manage or configure the
   network elements directly.

   On the other hand, when the network elements detect failure or some
   other changes, the network devices can send the affected multicast
   flows and the associated overlay/ transport/ underlay information to
   the controller.  Then the controller/ EMS/NMS can respond immediately
   due to the failure and distribute new model for the flows to the
   network nodes quickly.  Such as the changing of the failure overlay
   protocol to another one, as well as transport and underlay protocol.

   Specifically, in section 3, it provides a human readability of the
   whole multicast network through UML like class diagram, which frames
   different multicast components and correlates them in a readable
   fashion.  Then, based on this UML like class diagram, there is
   instantiated and detailed YANG model in Section 4.



Zhang, et al.           Expires 26 February 2022                [Page 5]


Internet-Draft          Multicast YANG Data Model            August 2021


   The usage of this model is flexible.  The multicast-keys indicate the
   flow characters.  The flow can be L3 multicast flow, or L2 flow which
   is also called BUM (Broadcast, Unknown unicast, Multicast) flow in
   EVPN ([RFC7432]) deployment.

   Among the multicast-keys, the group-address of L3 multicast flow and
   the mac-address of BUM flow are the most important keys.  The other
   keys are optional, and need not be all set.  For example, only group-
   address is set, this is (*,G) analogous.  If source-address and
   group-address are both set, this is (S,G) analogous.  In addition to
   the source-address and group-address, when vpn-rd is also set, this
   is MVPN use case.  If mac-address and vpn-rd are set, this is EVPN
   use case.  In case vni-value is set with associated group-address,
   etc., this is NVO3 multicast use case.

   *  When the controller manages all the ingress and egress routers for
      the flow, it sends the model that is set with flow characters,
      ingress and egress nodes information to the ingress and egress
      nodes.  Then the ingress and egress nodes can work without any
      other dynamic overlay protocols.

   *  When the controller manages the ingress nodes only for the flow,
      it sends the model that is set with the flow characters to the
      ingress nodes.  The dynamic overlay protocol can be set or not.
      If the overlay protocol is set, the nodes use the protocol to
      signal the flow information with other nodes.  If the overlay
      protocol is not set, the nodes use the local running overlay
      protocol to signal the flow information.

   *  When the transport protocol is set in the model, the nodes
      encapsulate the flow according to the transport protocol.  When
      the transport protocol is not set in the model, the nodes use the
      local configured transport protocol for encapsulation.

   *  When the transport protocol is set in the model, the underlay
      protocol may be set in the model also.  In case the underlay
      protocol is set, the nodes use the underlay protocol to signal and
      build the transport/forwarding layer.  In case the underlay
      protocol is not set, the nodes use the local configured underlay
      protocol to signal and build the transport/forwarding layer.

   *  More than one ingress node for a multicast flow can be set in the
      model.  In this situation, two or more ingress nodes can used for
      a multicast flow forwarding, the ingress routers can be backup for
      each other.  More information can be found in
      [I-D.szcl-mboned-redundant-ingress-failover].





Zhang, et al.           Expires 26 February 2022                [Page 6]


Internet-Draft          Multicast YANG Data Model            August 2021


1.5.1.  Example


                              +------------+
                              |            +---------------------------+
               +--------------+ Controller |                           |
               |              |            +-----------+               |
               |              +------------+           |               |
               |                                       |               |
               |     +-----------------------------+   |               |
               |     |                             |   |               |
               |     |                      +------+---+--+            |
               |     |                      |Egress router+--+ Receiver|
               |     |                      +------+------+            |
           +---+-----+----+                        |                   |
  Source +-|Ingress router|     BIER domain        |                   |
           +---------+----+                        |                   |
                     |                      +------+------+            |
                     |                      |Egress router+--+ Receiver|
                     |                      +------+----+-+            |
                     |                             |    |              |
                     +-----------------------------+    +--------------+

                            Figure 2: Example

   The network administrator can use the multicast model and associated
   models to deploy the multicast service.  For example, suppose that
   the flow for a multicast service is 233.252.0.0/16, the flow should
   be forwarded by BIER [RFC8279] with MPLS encapsulation [RFC8296].
   Corresponding IGP protocol which is used to build BIER transport
   layer is OSPF [RFC2328].

   In this model, the corresponding group-address that is in multicast-
   keys is set to 233.252.0.0/16, the transport technology is set to
   BIER.  The BIER underlay protocol is set to OSPF.  The model is sent
   to every edge router from the controller.  If the BIER transport
   layer which depends on OSPF has not been built in the network, the
   multicast YANG model may invoke the BIER YANG model that is defined
   in [I-D.ietf-bier-bier-yang] generation in the controller.  After the
   BIER transport layer is built, the ingress router encapsulates the
   multicast flow with BIER header and sends it into the network.
   Intermediate routers forward the flows to all the egress nodes by
   BIER forwarding.

   Another example for this figure is, the controller can act as the
   BIER overlay only.  The routers in the domain build BIER forwarding
   plane beforehand.  The controller sends the multicast group-address
   and/or the source-address to the edge routers in BIER domain only,



Zhang, et al.           Expires 26 February 2022                [Page 7]


Internet-Draft          Multicast YANG Data Model            August 2021


   without transport and underlay set in the model.  Then the ingres
   router can encapsulate the multicast flow with BIER encapsulation
   automatically.

2.  Design of the multicast model

2.1.  Scope of Model

   This model can be used to configure and manage Multicast service.
   The operational state data can be retrieved by this model.  The
   subscription and push mechanism defined in [RFC8639] and [RFC8641]
   can be implemented by the user to subscribe to notifications on the
   data nodes in this model.

   The model contains all the basic configuration parameters to operate
   the model.  Depending on the implementation choices, some systems may
   not allow some of the advanced parameters to be configurable.  The
   occasionally implemented parameters are modeled as optional features
   in this model.  This model can be extended, and it has been
   structured in a way that such extensions can be conveniently made.

2.2.  Specification

   The configuration data nodes cover configurations.  The container
   "multicast-model" is the top level container in this data model.  The
   presence of this container is expected to enable Multicast service
   functionality.  The notification is used to notify the controller
   that there is error and the error reason.

3.  Module Structure

   This model imports and augments the ietf-routing YANG model defined
   in [RFC8349].  Both configuration data nodes and state data nodes of
   [RFC8349] are augmented.

   The YANG data model defined in this document conforms to the Network
   Management Datastore Architecture (NMDA) [RFC8342].  The operational
   state data is combined with the associated configuration data in the
   same hierarchy [RFC8407].

3.1.  UML like Class Diagram for Multicast YANG data Model

   The following is a UML like diagram for Multicast YANG data Model.








Zhang, et al.           Expires 26 February 2022                [Page 8]


Internet-Draft          Multicast YANG Data Model            August 2021


                  +-----------+
            +-----+Multi|keys |
            |     +-----------+
            |     |Group Addr |
            |     +-----------+
            |     |Source Addr|    +--------+-----------------+
            |     +-----------+    |        |                 |
            |     |VPN Info   |    |        |          +------+-------+
            |     +-----------+    |  +-----+------+   | Ing/Eg Nodes |
            |     |VNI Info   |    |  |Overlay Tech|   +--------------+
            |     +-----------+    |  +------------+   |Ingress Nodes |
            |                      |  |    EVPN    |   +--------------+
            |                      |  +------------+   |Egress Nodes  |
            |            Contain   |  |    MLD     |   +-------+------+
            |     +-----------+    |  +------------+           | relate
            |     | Multicast +----+  |MLD-Snooping|          \|/
            +-----+  Overlay  |       +------------+  +----------------+
            |     |           |       |    MVPN    |  | BIER Nodes Info|
            |     +-----------+       +------------+  +----------------+
            |                         |    PIM     |  |     BFR-ID     |
            |                         +------------+  +----------------+
            |
   +--------+--+           +---------------+----------+----------+
   | Multicast |Contain    |               |          |          |
   |  Model    |           |            +--+---+  +---+----+  +--+---+
   +--------+--+           |            | BIER |  |BIER-TE |  | MPLS |
            |    +---------+--+         +------+  +--------+  +------+
            |    | Multicast  |
            +----+ Transport  | invoke  +-----+  +----------+ +-------+
            |    |            |         | PIM |  |Cisco Mode| |SR-P2MP|
            |    +---------+--+         +--+--+  +----+-----+ +---+---+
            |              |               |          |           |
            |              |               |          |           |
            |              +---------------+----------+-----------+
            |
            |               +--------------+---------+---------+
            |               |              |         |         |
            |               |           +--+---+  +--+---+  +--+--+
            |    +----------+--         | BABEL|  | BGP  |  |ISIS |
            |    | Multicast  |         +------+  +------+  +-----+
            +----+ Underlay   | invoke
                 |            |         +------+  +------+  +-----+
                 +----------+--         | OSPF |  | PIM  |  |RIFT |
                            |           +--+---+  +--+---+  +--+--+
                            |              |         |         |
                            +--------------+---------+---------+

       Figure 3: UML like Class Diagram for Multicast YANG data Model



Zhang, et al.           Expires 26 February 2022                [Page 9]


Internet-Draft          Multicast YANG Data Model            August 2021


3.2.  Model Structure


module: ietf-multicast-model
  +--rw multicast-model
     +--rw multicast-keys*
             [vpn-rd source-address group-address mac-address vni-value]
        +--rw vpn-rd                 rt-types:route-distinguisher
        +--rw source-address         ip-multicast-source-address
        +--rw group-address
        |       rt-types:ip-multicast-group-address
        +--rw mac-address            yang:mac-address
        +--rw vni-value              uint32
        +--rw multicast-overlay
        |  +--rw vni-type?          virtual-type
        |  +--rw ingress-egress
        |  |  +--rw ingress-nodes* [ingress-node]
        |  |  |  +--rw ingress-node    inet:ip-address
        |  |  +--rw egress-nodes* [egress-node]
        |  |     +--rw egress-node    inet:ip-address
        |  +--rw bier-ids {bier}?
        |  |  +--rw sub-domain?      uint16
        |  |  +--rw ingress-nodes* [ingress-node]
        |  |  |  +--rw ingress-node    uint16
        |  |  +--rw egress-nodes* [egress-node]
        |  |     +--rw egress-node    uint16
        |  +--rw dynamic-overlay
        |     +--rw type?   identityref
        |     +--rw mld
        |        +--rw mld-instance-group?
        |                rt-types:ip-multicast-group-address
        +--rw multicast-transport
        |  +--rw type?           identityref
        |  +--rw bier
        |  |  +--rw sub-domain?        uint16
        |  |  +--rw bitstringlength?   uint16
        |  |  +--rw set-identifier?    uint16
        |  |  +--rw (encap-type)?
        |  |     +--:(mpls)
        |  |     +--:(eth)
        |  |     +--:(ipv6)
        |  +--rw bier-te
        |  |  +--rw sub-domain?        uint16
        |  |  +--rw bitstringlength?   uint16
        |  |  +--rw set-identifier?    uint16
        |  |  +--rw (encap-type)?
        |  |  |  +--:(mpls)
        |  |  |  +--:(eth)



Zhang, et al.           Expires 26 February 2022               [Page 10]


Internet-Draft          Multicast YANG Data Model            August 2021


        |  |  |  +--:(ipv6)
        |  |  +--rw bitstring* [name]
        |  |     +--rw name           string
        |  |     +--rw bier-te-adj* [adj-id]
        |  |        +--rw adj-id    uint16
        |  +--rw cisco-mdt
        |  |  +--rw p-group?   rt-types:ip-multicast-group-address
        |  +--rw rsvp-te-p2mp
        |  |  +--rw template-name?   string
        |  +--rw pim
        |  |  +--rw source-address?   ip-multicast-source-address
        |  |  +--rw group-address
        |  |          rt-types:ip-multicast-group-address
        |  +--rw sr-p2mp
        |     +--rw ir-segment-lists* [name]
        |     |  +--rw name    string
        |     +--rw replication-segment* [replication-id node-id]
        |        +--rw replication-id    tree-sid
        |        +--rw node-id           inet:ip-address
        +--rw multicast-underlay
           +--rw type?   identityref
           +--rw ospf
           |  +--rw topology?   string
           +--rw isis
           |  +--rw topology?   string
           +--rw pim
              +--rw source-address?   ip-multicast-source-address
              +--rw group-address
                      rt-types:ip-multicast-group-address

  notifications:
    +---n ingress-egress-event
       +--ro event-type?        enumeration
       +--ro multicast-key
       |  +--ro vpn-rd?           rt-types:route-distinguisher
       |  +--ro source-address?   ip-multicast-source-address
       |  +--ro group-address?    rt-types:ip-multicast-group-address
       |  +--ro mac-address?      yang:mac-address
       |  +--ro vni-value?        uint32
       +--ro dynamic-overlay
       |  +--ro type?   identityref
       |  +--ro mld
       |     +--ro mld-instance-group?
       |             rt-types:ip-multicast-group-address
       +--ro transport-tech
       |  +--ro type?           identityref
       |  +--ro bier
       |  |  +--ro sub-domain?        uint16



Zhang, et al.           Expires 26 February 2022               [Page 11]


Internet-Draft          Multicast YANG Data Model            August 2021


       |  |  +--ro bitstringlength?   uint16
       |  |  +--ro set-identifier?    uint16
       |  |  +--ro (encap-type)?
       |  |     +--:(mpls)
       |  |     +--:(eth)
       |  |     +--:(ipv6)
       |  +--ro bier-te
       |  |  +--ro sub-domain?        uint16
       |  |  +--ro bitstringlength?   uint16
       |  |  +--ro set-identifier?    uint16
       |  |  +--ro (encap-type)?
       |  |  |  +--:(mpls)
       |  |  |  +--:(eth)
       |  |  |  +--:(ipv6)
       |  |  +--ro bitstring* [name]
       |  |     +--ro name           string
       |  |     +--ro bier-te-adj* [adj-id]
       |  |        +--ro adj-id    uint16
       |  +--ro cisco-mdt
       |  |  +--ro p-group?   rt-types:ip-multicast-group-address
       |  +--ro rsvp-te-p2mp
       |  |  +--ro template-name?   string
       |  +--ro pim
       |  |  +--ro source-address?   ip-multicast-source-address
       |  |  +--ro group-address
       |  |          rt-types:ip-multicast-group-address
       |  +--ro sr-p2mp
       |     +--ro ir-segment-lists* [name]
       |     |  +--ro name    string
       |     +--ro replication-segment* [replication-id node-id]
       |        +--ro replication-id    tree-sid
       |        +--ro node-id           inet:ip-address
       +--ro underlay-tech
          +--ro type?   identityref
          +--ro ospf
          |  +--ro topology?   string
          +--ro isis
          |  +--ro topology?   string
          +--ro pim
             +--ro source-address?   ip-multicast-source-address
             +--ro group-address
                     rt-types:ip-multicast-group-address


3.3.  Multicast YANG data model Configuration

   This model is used with other protocol data model to provide
   multicast service.



Zhang, et al.           Expires 26 February 2022               [Page 12]


Internet-Draft          Multicast YANG Data Model            August 2021


   This model includes multicast service keys and three layers: the
   multicast overlay, the transport layer and the multicast underlay
   information.  Multicast keys include the features of multicast flow,
   such as(vpnid, multicast source and multicast group) information.  In
   data center network, for fine-grained to gather the nodes belonging
   to the same virtual network, there may need VNI-related information
   to assist.

   Multicast overlay defines (ingress-node, egress-nodes) nodes
   information.  If the transport layer is BIER, there may define BIER
   information including (Subdomain, ingress-node BFR-id, egress-nodes
   BFR-id).  If no (ingress-node, egress-nodes) information are defined
   directly, there may need overlay multicast signaling technology, such
   as MLD or MVPN, to collect these nodes information.

   Multicast transport layer defines the type of transport technologies
   that can be used to forward multicast flow, including BIER forwarding
   type, MPLS forwarding type, or PIM forwarding type and so on.  One or
   several transport technologies could be defined at the same time.  As
   for the detailed parameters for each transport technology, this
   multicast YANG data model may invoke the corresponding protocol model
   to define them.

   Multicast underlay defines the type of underlay technologies, such as
   OSPF, ISIS, BGP, PIM or BABEL and so on.  One or several underlay
   technologies could be defined at the same time if there is protective
   requirement.  As for the specific parameters for each underlay
   technology, this multicast YANG data model can depend the
   corresponding protocol model to configure them as well.

   The configuration modeling branch is composed of the keys, overlay
   layer, transport layer and underlay layer.

3.4.  Multicast YANG data model State

   Multicast model states are the same with the configuration.

3.5.  Multicast YANG data model Notification

   The defined Notifications include the events of ingress or egress
   nodes.  Like ingress node failure, overlay/ transport/ underlay
   module loading/ unloading.  And the potential failure about some
   multicast flows and associated overlay/ transport/ underlay
   technologies.







Zhang, et al.           Expires 26 February 2022               [Page 13]


Internet-Draft          Multicast YANG Data Model            August 2021


4.  Multicast YANG data Model

   This module references [RFC1195], [RFC2328], [RFC4271], [RFC4541],
   [RFC4875], [RFC5340], [RFC6037], [RFC6388], [RFC6513], [RFC6991],
   [RFC7348], [RFC7432], [RFC7637], [RFC7716], [RFC7761], [RFC8279],
   [RFC8294], [RFC8296], [RFC8343], [RFC8344], [RFC8349], [RFC8639],
   [RFC8641], [RFC8926], [RFC8966], [I-D.ietf-pim-yang],
   [I-D.ietf-bier-bier-yang], [I-D.ietf-bier-te-arch],
   [I-D.ietf-bier-mld], [I-D.ietf-bess-evpn-bum-procedure-updates],
   [I-D.ietf-bier-evpn], [I-D.ietf-bier-bierin6],
   [I-D.ietf-bier-pim-signaling], [I-D.ietf-rift-rift],
   [I-D.ietf-isis-yang-isis-cfg].

   <CODE BEGINS> file "ietf-multicast-model@2021-08-26.yang"
   module ietf-multicast-model {

     yang-version 1.1;

     namespace "urn:ietf:params:xml:ns:yang:ietf-multicast-model";
     prefix ietf-multicast-model;

     import ietf-yang-types {
       prefix "yang";
       reference
         "RFC 6991: Common YANG Data Types";
     }

     import ietf-inet-types {
       prefix "inet";
       reference
         "RFC 6991: Common YANG Data Types";
     }
     import ietf-routing-types {
       prefix "rt-types";
       reference
         "RFC 8294: Common YANG Data Types for the Routing Area";
     }
     import ietf-routing {
       prefix "rt";
       reference
         "RFC 8349: A YANG Data Model for Routing Management
                    (NMDA Version)";
     }

     organization " IETF MBONED (MBONE Deployment) Working Group";
     contact
       "WG List:  <mailto:mboned@ietf.org>




Zhang, et al.           Expires 26 February 2022               [Page 14]


Internet-Draft          Multicast YANG Data Model            August 2021


        Editor:   Zheng Zhang
                  <mailto:zhang.zheng@zte.com.cn>
        Editor:   Cui Wang
                  <mailto:lindawangjoy@gmail.com>
        Editor:   Ying Cheng
                  <mailto:chengying10@chinaunicom.cn>
        Editor:   Xufeng Liu
                  <mailto:xufeng.liu.ietf@gmail.com>
        Editor:   Mahesh Sivakumar
                  <mailto:sivakumar.mahesh@gmail.com>
       ";

     // RFC Ed.: replace XXXX with actual RFC number and remove
     // this note

     description
       "The module defines the YANG definitions for multicast service
        management.

        Copyright (c) 2021 IETF Trust and the persons identified as
        authors of the code.  All rights reserved.

        Redistribution and use in source and binary forms, with or
        without modification, is permitted pursuant to, and subject
        to the license terms contained in, the Simplified BSD
        License set forth in Section 4.c of the IETF Trust's Legal
        Provisions Relating to IETF Documents
        (https://trustee.ietf.org/license-info).

        This version of this YANG module is part of RFC XXXX
        (https://www.rfc-editor.org/info/rfcXXXX); see the RFC
        itself for full legal notices.

        The key words 'MUST', 'MUST NOT', 'REQUIRED', 'SHALL',
        'SHALL NOT', 'SHOULD', 'SHOULD NOT', 'RECOMMENDED',
        'NOT RECOMMENDED', 'MAY', and 'OPTIONAL' in this document
        are to be interpreted as described in BCP 14 (RFC 2119)
        (RFC 8174) when, and only when, they appear in all
        capitals, as shown here.";

     revision 2021-08-26 {
       description
         "Initial revision.";
       reference
         "RFC XXXX: A YANG Data Model for multicast YANG.";
     }

     /*



Zhang, et al.           Expires 26 February 2022               [Page 15]


Internet-Draft          Multicast YANG Data Model            August 2021


      *feature
      */
     feature bier {
       description
         "Cooperation with BIER technology.";
       reference
         "RFC 8279:
            Multicast Using Bit Index Explicit Replication (BIER).";
     }

     /*
      *typedef
      */
     typedef ip-multicast-source-address {
       type union {
         type enumeration {
           enum * {
             description
               "Any source address.";
           }
         }
         type inet:ipv4-address;
         type inet:ipv6-address;
       }
       description
         "Multicast source IP address type.";
     }
     typedef tree-sid {
       type union {
         type rt-types:mpls-label;
         type inet:ip-prefix;
       }
       description
         "The type of the Segment Identifier of a Replication segment
          is a SR-MPLS label or a SRv6 SID.";
     }
     typedef virtual-type {
       type enumeration {
         enum vxlan {
           description
             "The VXLAN encapsulation is used for flow encapsulation.";
           reference
             "RFC 7348: Virtual eXtensible Local Area Network (VXLAN):
              A Framework for Overlaying Virtualized Layer 2 Networks
              over Layer 3 Networks.";
         }
         enum nvgre {
           description



Zhang, et al.           Expires 26 February 2022               [Page 16]


Internet-Draft          Multicast YANG Data Model            August 2021


             "The NVGRE encapsulation is used for flow encapsulation.";
           reference
             "RFC 7637: NVGRE: Network Virtualization Using Generic
              Routing Encapsulation.";
         }
         enum geneve {
           description
             "The GENEVE encapsulation is used for flow encapsulation.";
           reference
             "RFC 8926: Geneve: Generic Network
              Virtualization Encapsulation.";
         }
       }
       description
         "The encapsulation type used for the flow.
          When this type is set, the associated vni-value
          MUST be set.";
     } // virtual-type

     /*
      * Identities
      */

     identity multicast-model {
       base "rt:control-plane-protocol";
       description "Identity for the multicast model.";
     }
     identity overlay-type {
       description
         "Base identity for the type of multicast overlay technology.";
     }
     identity transport-type {
       description "Identity for the multicast transport technology.";
     }
     identity underlay-type {
       description "Identity for the multicast underlay technology.";
     }
     identity overlay-pim {
       base overlay-type;
       description
         "Using PIM as multicast overlay technology.
          For example, as BIER overlay.";
       reference
         "I-D.ietf-bier-pim-signaling:
            PIM Signaling Through BIER Core.";
     }
     identity mld {
       base overlay-type;



Zhang, et al.           Expires 26 February 2022               [Page 17]


Internet-Draft          Multicast YANG Data Model            August 2021


       description
         "Using MLD as multicast overlay technology.
          For example, as BIER overlay.";
       reference
         "I-D.ietf-bier-mld:
            BIER Ingress Multicast Flow Overlay
            using Multicast Listener Discovery Protocols.";
     }
     identity mld-snooping {
       base overlay-type;
       description
         "Using MLD as multicast overlay technology.
          For example, as BIER overlay.";
       reference
         "RFC 4541:
            Considerations for Internet Group Management
            Protocol (IGMP) and Multicast Listener
            Discovery (MLD) Snooping Switches.";
     }
     identity evpn {
       base overlay-type;
       description
         "Using EVPN as multicast overlay technology.";
       reference
         "RFC 7432: BGP MPLS-Based Ethernet VPN.
          I-D.ietf-bess-evpn-bum-procedure-updates:
            Updates on EVPN BUM Procedures.
          I-D.ietf-bier-evpn: EVPN BUM Using BIER.";
     }
     identity mvpn {
       base overlay-type;
       description
         "Using MVPN as multicast overlay technology.";
       reference
         "RFC 6513: Multicast in MPLS/BGP IP VPNs.
          RFC 7716:
            Global Table Multicast with BGP Multicast VPN
            (BGP-MVPN) Procedures.";
     }
     identity bier {
       base transport-type;
       description
         "Using BIER as multicast transport technology.";
       reference
         "RFC 8279:
            Multicast Using Bit Index Explicit Replication (BIER).";
     }
     identity bier-te {



Zhang, et al.           Expires 26 February 2022               [Page 18]


Internet-Draft          Multicast YANG Data Model            August 2021


       base transport-type;
       description
         "Using BIER-TE as multicast transport technology.";
       reference
         "I-D.ietf-bier-te-arch:
            Traffic Engineering for Bit Index Explicit Replication
            (BIER-TE)";
     }
     identity mldp {
       base transport-type;
       description
         "Using mLDP as multicast transport technology.";
       reference
         "RFC 6388:
            Label Distribution Protocol Extensions
            for Point-to-Multipoint and Multipoint-to-Multipoint
            Label Switched Paths.
          I-D.ietf-mpls-mldp-yang: YANG Data Model for MPLS mLDP.";
     }
     identity rsvp-te-p2mp {
       base transport-type;
       description
         "Using P2MP TE as multicast transport technology.";
       reference
         "RFC 4875:
            Extensions to Resource Reservation Protocol
            - Traffic Engineering (RSVP-TE) for Point-to-Multipoint
            TE Label Switched Paths (LSPs).";
     }
     identity sr-p2mp {
       base transport-type;
       description
         "Using Segment Routing  as multicast transport technology.";
       reference
         "I-D.ietf-pim-sr-p2mp-policy:
            Segment Routing Point-to-Multipoint Policy.";
     }
     identity cisco-mdt {
       base transport-type;
       description
         "Using cisco MDT for multicast transport technology.";
       reference
         "RFC 6037:
            Cisco Systems' Solution for Multicast in BGP/MPLS IP VPNs";
     }
     identity pim {
       base transport-type;
       base underlay-type;



Zhang, et al.           Expires 26 February 2022               [Page 19]


Internet-Draft          Multicast YANG Data Model            August 2021


       description
         "Using PIM as multicast transport technology.";
       reference
         "RFC 7761:
            Protocol Independent Multicast - Sparse Mode
            (PIM-SM): Protocol Specification (Revised).";
     }
     identity bgp {
       base underlay-type;
       description
         "Using BGP as underlay technology to build the multicast
          transport layer. For example, using BGP as BIER underlay.";
       reference
         "I-D.ietf-bier-idr-extensions: BGP Extensions for BIER.";
     }
     identity ospf  {
       base underlay-type;
       description
         "Using OSPF as multicast underlay technology.
          For example, using OSPF as BIER underlay.";
       reference
         "RFC 8444:
            OSPFv2 Extensions for Bit Index Explicit Replication (BIER),
          I-D.ietf-bier-ospfv3-extensions:
            OSPFv3 Extensions for BIER.";
     }
     identity isis {
       base underlay-type;
       description
         "Using ISIS as multicast underlay technology.
          For example, using ISIS as BIER underlay.";
       reference
         "RFC 8401:
            Bit Index Explicit Replication (BIER) Support via IS-IS";
     }
     identity babel {
       base underlay-type;
       description
         "Using BABEL as multicast underlay technology.
          For example, using BABEL as BIER underlay.";
       reference
         "RFC 8966: The Babel Routing Protocol
          I-D.zhang-bier-babel-extensions: BIER in BABEL";
     }
     identity rift {
       base underlay-type;
       description
         "Using RIFT as multicast underlay technology.



Zhang, et al.           Expires 26 February 2022               [Page 20]


Internet-Draft          Multicast YANG Data Model            August 2021


          For example, using RIFT as BIER underlay.";
       reference
         "I-D.ietf-rift-rift: RIFT: Routing in Fat Trees.
          I-D.zzhang-bier-rift: Supporting BIER with RIFT";
     }

     grouping general-multicast-key {
       description
         "The general multicast keys. They are used to distinguish
          different multicast service.";
       leaf vpn-rd {
         type rt-types:route-distinguisher;
         description
           "A Route Distinguisher used to distinguish
            routes from different MVPNs.";
         reference
           "RFC 8294: Common YANG Data Types for the Routing Area.
            RFC 6513: Multicast in MPLS/BGP IP VPNs.";
       }
       leaf source-address {
         type ip-multicast-source-address;
         description
           "The IPv4/IPv6 source address of the multicast flow. The
            value set to zero means that the receiver interests
            in all source that relevant to one given group.";
       }
       leaf group-address {
         type rt-types:ip-multicast-group-address;
         description
           "The IPv4/IPv6 group address of multicast flow. This
            type represents a version-neutral IP multicast group
            address. The format of the textual representation
            implies the IP version.";
         reference
           "RFC 8294: Common YANG Data Types for the Routing Area.";
       }
       leaf mac-address {
         type yang:mac-address;
         description
           "The mac address of flow. In the EVPN situation, the L2
            flow that is called
            BUM (Broadcast, Unknown Unicast, Multicast)
            can be sent to the other PEs that
            are in a same broadcast domain.";
         reference
           "RFC 6991: Common YANG Data Types.
            RFC 7432: BGP MPLS-Based Ethernet VPN.";
       }



Zhang, et al.           Expires 26 February 2022               [Page 21]


Internet-Draft          Multicast YANG Data Model            August 2021


       leaf vni-value {
         type uint32;
         description
           "The value of Vxlan network identifier, virtual subnet ID
            or virtual net identifier. This value and vni-type is used
            to indicate a specific virtual multicast service.";
       }
     } // general-multicast-key

     grouping encap-type {
       description
         "The encapsulation type used for flow forwarding.
          This encapsulation acts as the inner encapsulation,
          as compare to the outer multicast-transport encapsulation.";
       choice encap-type {
         case mpls {
           description "The BIER forwarding depends on mpls.";
           reference
             "RFC 8296: Encapsulation for Bit Index Explicit
              Replication (BIER) in MPLS and Non-MPLS Networks.";
         }
         case eth {
           description "The BIER forwarding depends on ethernet.";
           reference
             "RFC 8296: Encapsulation for Bit Index Explicit
              Replication (BIER) in MPLS and Non-MPLS Networks.";
         }
         case ipv6 {
           description "The BIER forwarding depends on IPv6.";
           reference
             "I-D.ietf-bier-bierin6: BIER in IPv6 (BIERin6)";
         }
         description "The encapsulation type in BIER.";
       }
     } // encap-type

     grouping bier-key {
       description
         "The key parameters set for BIER/BIER TE forwarding.";
       reference
         "RFC 8279: Multicast Using Bit Index Explicit Replication
          (BIER).";

       leaf sub-domain {
         type uint16;
         description
           "The subdomain id that the multicast flow belongs to.";
       }



Zhang, et al.           Expires 26 February 2022               [Page 22]


Internet-Draft          Multicast YANG Data Model            August 2021


       leaf bitstringlength {
         type uint16;
         description
           "The bitstringlength used by BIER forwarding.";
       }
       leaf set-identifier {
         type uint16;
         description
           "The set identifier used by the multicast flow.";
       }
       uses encap-type;
     }

     grouping transport-tech {
       description
         "The transport technology selected for the multicast service.
          For one specific multicast flow, it's better to use only one
          transport technology for forwarding.";

       leaf type {
         type identityref {
           base transport-type;
         }
         description "The type of transport technology";
       }
       container bier {
         when "../type = 'ietf-multicast-model:bier'" {
            description
              "Only when BIER is used as transport technology.";
         }
         description
           "The transport technology is BIER. The BIER technology
            is introduced in RFC8279. The parameters are consistent
            with the definition in BIER YANG data model.";
         reference
           "I-D.ietf-bier-bier-yang:
              YANG Data Model for BIER Protocol.";
         uses bier-key;
       }
       container bier-te {
         when "../type = 'ietf-multicast-model:bier-te'" {
            description
              "Only when BIER-TE is used as transport technology.";
         }
         description
           "The BIER-TE parameter that may need to be set.
            The parameters are consistent with the definition in
            BIER and BIER TE YANG data model.";



Zhang, et al.           Expires 26 February 2022               [Page 23]


Internet-Draft          Multicast YANG Data Model            August 2021


         reference
           "I-D.ietf-bier-bier-yang:
              YANG Data Model for BIER Protocol
            I-D.ietf-bier-te-yang:
              A YANG data model for Traffic Engineering for Bit Index
              Explicit Replication (BIER-TE)";

         uses bier-key;

         list bitstring {
           key "name";
           leaf name {
             type string;
             description "The name of the bitstring";
           }
           list bier-te-adj {
             key "adj-id";
             leaf adj-id {
               type uint16;
               description
                 "The link adjacency ID used for BIER TE forwarding.";
             }
             description
               "The adjacencies ID used for BIER TE bitstring
                encapsulation.";
           }
           description
             "The bitstring name and detail used for BIER TE
              forwarding encapsulation. One or more bitstring can be
              used for backup path.";
         }
       }
       container cisco-mdt {
         when "../type = 'ietf-multicast-model:cisco-mdt'" {
            description
              "Only when cisco MDT is used as transport technology.";
         }
         description "The MDT parameter that may need to be set.";
         leaf p-group {
           type rt-types:ip-multicast-group-address;
           description
             "The address of p-group. It is used to encapsulate
              and forward flow according to multicast tree from
              ingress node to egress nodes.";
         }
       }
       container rsvp-te-p2mp {
         when "../type = 'ietf-multicast-model:rsvp-te-p2mp'" {



Zhang, et al.           Expires 26 February 2022               [Page 24]


Internet-Draft          Multicast YANG Data Model            August 2021


          description
            "Only when RSVP TE P2MP is used as transport technology.";
         }
         description
           "The parameter that may be set. They are consistent with
           the definition in TE data model.";
         reference
           "RFC 8776: Common YANG Data Types for Traffic Engineering";

         leaf template-name {
           type string {
             pattern '/?([a-zA-Z0-9\-_.]+)(/[a-zA-Z0-9\-_.]+)*';
           }
           description
             "A type for the name of a TE node template or TE link
              template.";
         }
       }
       container pim {
         when "../type = 'ietf-multicast-model:pim'" {
            description
              "Only when PIM is used as transport technology.";
         }
         description "The PIM parameter that may need to be set.";
         uses pim;
       }
       container sr-p2mp {
         when "../type = 'ietf-multicast-model:sr-p2mp'" {
            description
              "Only when segment routing P2MP is used as transport
               technology.";
         }
         description "The SR-P2MP parameter that may need to be set.";
         list ir-segment-lists {
           key "name";
           leaf name {
             type string;
             description "Segment-list name";
           }
           description
             "The segment lists used for ingress replication.
              The name refers a segment list.";
         }

         list replication-segment {
           key "replication-id node-id";
           leaf replication-id {
             type tree-sid;



Zhang, et al.           Expires 26 February 2022               [Page 25]


Internet-Draft          Multicast YANG Data Model            August 2021


             description
               "The identifier for a Replication segment that is
                unique in context of the Replication Node.
                This is a SR-MPLS label or a SRv6 SID";
           }
           leaf node-id {
             type inet:ip-address;
             description
               "The address of the Replication Node that the
                Replication segment is for.";
           }
           description
             "A Multi-point service delivery could be realized via
              P2MP trees in a Segment Routing domain.
              It may consist of one or more Replication segment";
           reference
             "I-D.ietf-spring-sr-replication-segment:
                SR Replication Segment for Multi-point Service
                Delivery.";
         }
       } // sr-p2mp
     } // transport-tech

     grouping underlay-tech {
       description
         "The underlay technology selected for the transport layer.
          The underlay technology has no straight relationship with
          the multicast overlay, it is used for transport path
          building, for example BIER forwarding path building.";

       leaf type {
         type identityref {
           base underlay-type;
         }
         description "The type of underlay technology";
       }
       container ospf {
         when "../type = 'ietf-multicast-model:ospf'" {
            description
              "Only when OSPF is used as underay technology.";
         }
         description
           "If OSPF protocol supports multiple topology feature,
            the associated topology name may be assigned.
            In case the topology name is assigned, the specific
            OSPF topology is used for underly to building the
            transport layer.";
         reference



Zhang, et al.           Expires 26 February 2022               [Page 26]


Internet-Draft          Multicast YANG Data Model            August 2021


           "RFC 4915: Multi-Topology Routing";
         leaf topology {
           type string;
           description
             "The designed topology name of ospf protocol.";
         }
       }
       container isis {
         when "../type = 'ietf-multicast-model:isis'" {
            description
              "Only when ISIS is used as underay technology.";
         }
         description
           "If ISIS protocol supports multiple topology feature,
            the associated topology name may be assigned.
            In case the topology name is assigned, the specific
            ISIS topology is used for underly to building the
            transport layer.";
         reference
           "RFC 5120: M-IS-IS: Multi Topology Routing in IS-IS";
         leaf topology {
           type string;
           description
             "The designed topology name of isis protocol.";
         }
       }
       container pim {
         when "../type = 'ietf-multicast-model:pim'" {
            description
              "Only when PIM is used as underay technology.";
         }
         description "The PIM parameter that may need to be set.";
         uses pim;
       }
     } // underlay-tech

     /*overlay*/

     grouping overlay-tech {
       container dynamic-overlay {
         leaf type {
           type identityref {
             base overlay-type;
           }
           description "The type of overlay technology";
         }
         container mld {
           when "../type = 'ietf-multicast-model:mld'" {



Zhang, et al.           Expires 26 February 2022               [Page 27]


Internet-Draft          Multicast YANG Data Model            August 2021


              description
                "Only when MLD is used as overlay technology.";
           }
           description "The MLD parameter that may need to be set.";
           leaf mld-instance-group {
             type rt-types:ip-multicast-group-address;
             description
               "The multicast address used for multiple MLD instance
                support.";
           }
         }
         description
           "The dynamic overlay technologies and associated parameter
            that may be set.";
       }
       description "The overlay technology used for multicast service.";
     } // overlay-tech

     /*transport*/

     grouping pim {
       description
         "The required information of pim transportion.";
       leaf source-address {
         type ip-multicast-source-address;
         description
           "The IPv4/IPv6 source address of the multicast flow. The
            value set to zero means that the receiver interests
            in all source that relevant to one given group.";
       }
       leaf group-address {
         type rt-types:ip-multicast-group-address;
         mandatory true;
         description
           "The IPv4/IPv6 group address of multicast flow. This
            type represents a version-neutral IP multicast group
            address. The format of the textual representation
            implies the IP version.";
       }
       reference
         "RFC 7761: Protocol Independent Multicast - Sparse Mode
                    (PIM-SM): Protocol Specification (Revised).";
     } //pim

     /*underlay*/

     container multicast-model {
       description



Zhang, et al.           Expires 26 February 2022               [Page 28]


Internet-Draft          Multicast YANG Data Model            August 2021


         "The model of multicast YANG data. Include keys, overlay,
          transport and underlay.";

       list multicast-keys{
         key "vpn-rd source-address group-address mac-address vni-value";
         uses general-multicast-key;

         container multicast-overlay {
           description
             "The overlay information of multicast service.
              Overlay technology is used to exchange multicast
              flows information. Overlay technology may not be
              used in SDN controlled completely situation, but
              it can be used in partial SDN controlled situation
              or non-SDN controlled situation. Different overlay
              technologies can be choosed according to different
              deploy consideration.";

           leaf vni-type {
             type virtual-type;
             description
               "The encapsulated type for the multicast flow,
                it is used to carry the virtual network identifier
                for the multicast service.";
           }

           container ingress-egress {
             description
               "The ingress and egress nodes address collection.
                The ingress node may use the egress nodes set
                directly to encapsulate the multicast flow by
                transport technology.";

             list ingress-nodes {
               key "ingress-node";
               description
                 "The egress nodes of multicast flow.";

               leaf ingress-node {
                 type inet:ip-address;
                 description
                   "The ip address of ingress node for one or more
                    multicast flow. Or the ingress node of MVPN and
                    BIER. In MVPN, this is the address of ingress
                    PE; in BIER, this is the BFR-prefix of ingress
                    nodes.
                    Two or more ingress nodes may existed for the
                    redundant ingress node protection.";



Zhang, et al.           Expires 26 February 2022               [Page 29]


Internet-Draft          Multicast YANG Data Model            August 2021


               }
             }

             list egress-nodes {
               key "egress-node";
               description
                 "The egress multicast nodes of the multicast flow.
                  Or the egress node of MVPN and BIER. In MVPN, this
                  is the address of egress PE; in BIER, this is the
                  BFR-prefix of ingress nodes.";

               leaf egress-node {
                 type inet:ip-address;
                 description
                   "The ip-address set of egress multicast nodes.";
               }
             }
           }

           container bier-ids {
             if-feature bier;
             description
               "The BFR-ids of ingress and egress BIER nodes for
                one or more multicast flows. This overlay is used
                with BIER transport technology. The egress nodes
                set can be used to encapsulate the multicast flow
                directly in the ingress node.";
             reference
               "RFC 8279: Multicast Using Bit Index Explicit
                Replication (BIER)";

             leaf sub-domain {
               type uint16;
               description
                 "The sub-domain that this multicast flow belongs to.";
             }
             list ingress-nodes {
               key "ingress-node";
               description
                 "The ingress nodes of multicast flow.";
               leaf ingress-node {
                 type uint16;
                 description
                   "The ingress node of multicast flow. This is the
                    BFR-id of ingress nodes.";
               }
             }
             list egress-nodes {



Zhang, et al.           Expires 26 February 2022               [Page 30]


Internet-Draft          Multicast YANG Data Model            August 2021


               key "egress-node";
               description
                 "The egress nodes of multicast flow.";

               leaf egress-node {
                 type uint16;
                 description
                   "The BFR-ids of egress multicast BIER nodes.";
               }
             }
           }
           uses overlay-tech;
         }

         container multicast-transport {
           description
             "The transportion of multicast service. Transport
              protocol is responsible for delivering multicast
              flows from ingress nodes to egress nodes with or
              without specific encapsulation. Different transport
              technology can be choosed according to different
              deploy consideration. Once a transport technology
              is choosed, associated protocol should be triggered
              to run.";

           uses transport-tech;
         }
         container multicast-underlay {
           description
             "The underlay of multicast service. Underlay protocol
              is used to build transport layer. Underlay protocol
              need not be assigned in ordinary network since
              existed underlay protocol fits well, but it can be
              assigned in particular networks for better
              controll. Once a underlay technology is choosed,
              associated protocol should be triggered to run.";

           uses underlay-tech;
         }
         description
           "The model of multicast YANG data. Include keys,
            overlay, transport and underlay.";
       }
     }

     /*Notifications*/

     notification ingress-egress-event {



Zhang, et al.           Expires 26 February 2022               [Page 31]


Internet-Draft          Multicast YANG Data Model            August 2021


       leaf event-type {
         type enumeration {
           enum down {
             description
               "There is something wrong with ingress or egress node,
                and node can't work properlay.";
           }
           enum protocol-enabled {
             description
               "The protocol that is used for multicast
                flows have been enabled.";
           }
           enum protocol-disabled {
             description
               "The protocol that is used by multicast
                flows have been disabled.";
           }
         }
         description "Event type.";
       }
       container multicast-key {
         uses general-multicast-key;
         description
           "The associated multicast keys that are influenced by
            ingress or egress node failer.";
       }
       uses overlay-tech;

       container transport-tech {
         description
           "The modules can be used to forward multicast flows.";
         uses transport-tech;
       }

       container underlay-tech {
         description
           "There is something wrong with the module which is
            used to build multicast transport layer.";
         uses underlay-tech;
       }
       description
         "Notification events for the ingress or egress nodes. Like
          node failer, overlay/ transport/ underlay module
          loading/ unloading. And the potential failer about some
          multicast flows and associated
          overlay/ transport/ underlay technologies.";
     }
   }



Zhang, et al.           Expires 26 February 2022               [Page 32]


Internet-Draft          Multicast YANG Data Model            August 2021


   <CODE ENDS>


5.  Security Considerations

   The YANG module specified in this document defines a schema for data
   that is designed to be accessed via network management protocols such
   as NETCONF [RFC6241] or RESTCONF [RFC8040].  The lowest NETCONF layer
   is the secure transport layer, and the mandatory-to-implement secure
   transport is Secure Shell (SSH) [RFC6242].  The lowest RESTCONF layer
   is HTTPS, and the mandatory-to-implement secure transport is TLS
   [RFC8446].

   The NETCONF access control model [RFC8341] provides the means to
   restrict access for particular NETCONF or RESTCONF users to a
   preconfigured subset of all available NETCONF or RESTCONF protocol
   operations and content.

   There are a number of data nodes defined in this YANG module that are
   writable/creatable/deletable (i.e., config true, which is the
   default).  These data nodes may be considered sensitive or vulnerable
   in some network environments.  Write operations (e.g., edit-config)
   to these data nodes without proper protection can have a negative
   effect on network operations.  These are data nodes and their
   sensitivity/vulnerability:

   Under /rt:routing/rt:control-plane-protocols/multicast-model,

   multicast-model

   *  These data nodes in this model specifies the configuration for the
      multicast service at the top level.  Modifying the configuration
      can cause multicast service to be deleted or reconstructed.

   Some of the readable data nodes in this YANG module may be considered
   sensitive or vulnerable in some network environments.  It is thus
   important to control read access (e.g., via get, get-config, or
   notification) to these data nodes.  These are the data nodes and
   their sensitivity/vulnerability:

   /rt:routing/rt:control-plane-protocols/multicast-model,

   Unauthorized access to any data node of the above tree can disclose
   the operational state information of multicast service on this
   device.






Zhang, et al.           Expires 26 February 2022               [Page 33]


Internet-Draft          Multicast YANG Data Model            August 2021


6.  IANA Considerations

   RFC Ed.: Please replace all occurrences of 'XXXX' with the actual RFC
   number (and remove this note).

   The IANA is requested to assign one new URI from the IETF XML
   registry [RFC3688].  Authors are suggesting the following URI:

   URI: urn:ietf:params:xml:ns:yang:ietf-multicast-model

   Registrant Contact: The IESG

   XML: N/A, the requested URI is an XML namespace

   This document also requests one new YANG module name in the YANG
   Module Names registry [RFC6020] with the following suggestion:

   name: ietf-multicast-model

   namespace: urn:ietf:params:xml:ns:yang:ietf-multicast-model

   prefix: multicast-model

   reference: RFC XXXX

7.  Acknowledgements

   The authors would like to thank Stig Venaas, Jake Holland, Min Gu,
   Gyan Mishra for their valuable comments and suggestions.

8.  References

8.1.  Normative References

   [RFC1195]  Callon, R., "Use of OSI IS-IS for routing in TCP/IP and
              dual environments", RFC 1195, DOI 10.17487/RFC1195,
              December 1990, <https://www.rfc-editor.org/info/rfc1195>.

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119,
              DOI 10.17487/RFC2119, March 1997,
              <https://www.rfc-editor.org/info/rfc2119>.

   [RFC2328]  Moy, J., "OSPF Version 2", STD 54, RFC 2328,
              DOI 10.17487/RFC2328, April 1998,
              <https://www.rfc-editor.org/info/rfc2328>.





Zhang, et al.           Expires 26 February 2022               [Page 34]


Internet-Draft          Multicast YANG Data Model            August 2021


   [RFC4271]  Rekhter, Y., Ed., Li, T., Ed., and S. Hares, Ed., "A
              Border Gateway Protocol 4 (BGP-4)", RFC 4271,
              DOI 10.17487/RFC4271, January 2006,
              <https://www.rfc-editor.org/info/rfc4271>.

   [RFC4875]  Aggarwal, R., Ed., Papadimitriou, D., Ed., and S.
              Yasukawa, Ed., "Extensions to Resource Reservation
              Protocol - Traffic Engineering (RSVP-TE) for Point-to-
              Multipoint TE Label Switched Paths (LSPs)", RFC 4875,
              DOI 10.17487/RFC4875, May 2007,
              <https://www.rfc-editor.org/info/rfc4875>.

   [RFC5340]  Coltun, R., Ferguson, D., Moy, J., and A. Lindem, "OSPF
              for IPv6", RFC 5340, DOI 10.17487/RFC5340, July 2008,
              <https://www.rfc-editor.org/info/rfc5340>.

   [RFC6020]  Bjorklund, M., Ed., "YANG - A Data Modeling Language for
              the Network Configuration Protocol (NETCONF)", RFC 6020,
              DOI 10.17487/RFC6020, October 2010,
              <https://www.rfc-editor.org/info/rfc6020>.

   [RFC6241]  Enns, R., Ed., Bjorklund, M., Ed., Schoenwaelder, J., Ed.,
              and A. Bierman, Ed., "Network Configuration Protocol
              (NETCONF)", RFC 6241, DOI 10.17487/RFC6241, June 2011,
              <https://www.rfc-editor.org/info/rfc6241>.

   [RFC6242]  Wasserman, M., "Using the NETCONF Protocol over Secure
              Shell (SSH)", RFC 6242, DOI 10.17487/RFC6242, June 2011,
              <https://www.rfc-editor.org/info/rfc6242>.

   [RFC6388]  Wijnands, IJ., Ed., Minei, I., Ed., Kompella, K., and B.
              Thomas, "Label Distribution Protocol Extensions for Point-
              to-Multipoint and Multipoint-to-Multipoint Label Switched
              Paths", RFC 6388, DOI 10.17487/RFC6388, November 2011,
              <https://www.rfc-editor.org/info/rfc6388>.

   [RFC6513]  Rosen, E., Ed. and R. Aggarwal, Ed., "Multicast in MPLS/
              BGP IP VPNs", RFC 6513, DOI 10.17487/RFC6513, February
              2012, <https://www.rfc-editor.org/info/rfc6513>.

   [RFC6991]  Schoenwaelder, J., Ed., "Common YANG Data Types",
              RFC 6991, DOI 10.17487/RFC6991, July 2013,
              <https://www.rfc-editor.org/info/rfc6991>.

   [RFC7432]  Sajassi, A., Ed., Aggarwal, R., Bitar, N., Isaac, A.,
              Uttaro, J., Drake, J., and W. Henderickx, "BGP MPLS-Based
              Ethernet VPN", RFC 7432, DOI 10.17487/RFC7432, February
              2015, <https://www.rfc-editor.org/info/rfc7432>.



Zhang, et al.           Expires 26 February 2022               [Page 35]


Internet-Draft          Multicast YANG Data Model            August 2021


   [RFC7716]  Zhang, J., Giuliano, L., Rosen, E., Ed., Subramanian, K.,
              and D. Pacella, "Global Table Multicast with BGP Multicast
              VPN (BGP-MVPN) Procedures", RFC 7716,
              DOI 10.17487/RFC7716, December 2015,
              <https://www.rfc-editor.org/info/rfc7716>.

   [RFC7761]  Fenner, B., Handley, M., Holbrook, H., Kouvelas, I.,
              Parekh, R., Zhang, Z., and L. Zheng, "Protocol Independent
              Multicast - Sparse Mode (PIM-SM): Protocol Specification
              (Revised)", STD 83, RFC 7761, DOI 10.17487/RFC7761, March
              2016, <https://www.rfc-editor.org/info/rfc7761>.

   [RFC7950]  Bjorklund, M., Ed., "The YANG 1.1 Data Modeling Language",
              RFC 7950, DOI 10.17487/RFC7950, August 2016,
              <https://www.rfc-editor.org/info/rfc7950>.

   [RFC7951]  Lhotka, L., "JSON Encoding of Data Modeled with YANG",
              RFC 7951, DOI 10.17487/RFC7951, August 2016,
              <https://www.rfc-editor.org/info/rfc7951>.

   [RFC8040]  Bierman, A., Bjorklund, M., and K. Watsen, "RESTCONF
              Protocol", RFC 8040, DOI 10.17487/RFC8040, January 2017,
              <https://www.rfc-editor.org/info/rfc8040>.

   [RFC8174]  Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
              2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
              May 2017, <https://www.rfc-editor.org/info/rfc8174>.

   [RFC8279]  Wijnands, IJ., Ed., Rosen, E., Ed., Dolganow, A.,
              Przygienda, T., and S. Aldrin, "Multicast Using Bit Index
              Explicit Replication (BIER)", RFC 8279,
              DOI 10.17487/RFC8279, November 2017,
              <https://www.rfc-editor.org/info/rfc8279>.

   [RFC8294]  Liu, X., Qu, Y., Lindem, A., Hopps, C., and L. Berger,
              "Common YANG Data Types for the Routing Area", RFC 8294,
              DOI 10.17487/RFC8294, December 2017,
              <https://www.rfc-editor.org/info/rfc8294>.

   [RFC8296]  Wijnands, IJ., Ed., Rosen, E., Ed., Dolganow, A.,
              Tantsura, J., Aldrin, S., and I. Meilik, "Encapsulation
              for Bit Index Explicit Replication (BIER) in MPLS and Non-
              MPLS Networks", RFC 8296, DOI 10.17487/RFC8296, January
              2018, <https://www.rfc-editor.org/info/rfc8296>.

   [RFC8340]  Bjorklund, M. and L. Berger, Ed., "YANG Tree Diagrams",
              BCP 215, RFC 8340, DOI 10.17487/RFC8340, March 2018,
              <https://www.rfc-editor.org/info/rfc8340>.



Zhang, et al.           Expires 26 February 2022               [Page 36]


Internet-Draft          Multicast YANG Data Model            August 2021


   [RFC8341]  Bierman, A. and M. Bjorklund, "Network Configuration
              Access Control Model", STD 91, RFC 8341,
              DOI 10.17487/RFC8341, March 2018,
              <https://www.rfc-editor.org/info/rfc8341>.

   [RFC8342]  Bjorklund, M., Schoenwaelder, J., Shafer, P., Watsen, K.,
              and R. Wilton, "Network Management Datastore Architecture
              (NMDA)", RFC 8342, DOI 10.17487/RFC8342, March 2018,
              <https://www.rfc-editor.org/info/rfc8342>.

   [RFC8343]  Bjorklund, M., "A YANG Data Model for Interface
              Management", RFC 8343, DOI 10.17487/RFC8343, March 2018,
              <https://www.rfc-editor.org/info/rfc8343>.

   [RFC8344]  Bjorklund, M., "A YANG Data Model for IP Management",
              RFC 8344, DOI 10.17487/RFC8344, March 2018,
              <https://www.rfc-editor.org/info/rfc8344>.

   [RFC8349]  Lhotka, L., Lindem, A., and Y. Qu, "A YANG Data Model for
              Routing Management (NMDA Version)", RFC 8349,
              DOI 10.17487/RFC8349, March 2018,
              <https://www.rfc-editor.org/info/rfc8349>.

   [RFC8446]  Rescorla, E., "The Transport Layer Security (TLS) Protocol
              Version 1.3", RFC 8446, DOI 10.17487/RFC8446, August 2018,
              <https://www.rfc-editor.org/info/rfc8446>.

8.2.  Informative References

   [I-D.ietf-bess-evpn-bum-procedure-updates]
              Zhang, Z., Lin, W., Rabadan, J., Patel, K., and A.
              Sajassi, "Updates on EVPN BUM Procedures", Work in
              Progress, Internet-Draft, draft-ietf-bess-evpn-bum-
              procedure-updates-09, 9 June 2021,
              <https://www.ietf.org/archive/id/draft-ietf-bess-evpn-bum-
              procedure-updates-09.txt>.

   [I-D.ietf-bier-bier-yang]
              Chen, R., Hu, F., Zhang, Z., Dai, X., and M. Sivakumar,
              "YANG Data Model for BIER Protocol", Work in Progress,
              Internet-Draft, draft-ietf-bier-bier-yang-07, 8 September
              2020, <https://www.ietf.org/archive/id/draft-ietf-bier-
              bier-yang-07.txt>.

   [I-D.ietf-bier-bierin6]
              Zhang, Z., Zhang, Z., Wijnands, I., Mishra, M., Bidgoli,
              H., and G. Mishra, "Supporting BIER in IPv6 Networks
              (BIERin6)", Work in Progress, Internet-Draft, draft-ietf-



Zhang, et al.           Expires 26 February 2022               [Page 37]


Internet-Draft          Multicast YANG Data Model            August 2021


              bier-bierin6-00, 14 June 2021,
              <https://www.ietf.org/archive/id/draft-ietf-bier-
              bierin6-00.txt>.

   [I-D.ietf-bier-evpn]
              Zhang, Z., Przygienda, A., Sajassi, A., and J. Rabadan,
              "EVPN BUM Using BIER", Work in Progress, Internet-Draft,
              draft-ietf-bier-evpn-04, 2 December 2020,
              <https://www.ietf.org/archive/id/draft-ietf-bier-evpn-
              04.txt>.

   [I-D.ietf-bier-mld]
              Pfister, P., Wijnands, I., Venaas, S., Wang, C., Zhang,
              Z., and M. Stenberg, "BIER Ingress Multicast Flow Overlay
              using Multicast Listener Discovery Protocols", Work in
              Progress, Internet-Draft, draft-ietf-bier-mld-05, 22
              February 2021, <https://www.ietf.org/archive/id/draft-
              ietf-bier-mld-05.txt>.

   [I-D.ietf-bier-pim-signaling]
              Bidgoli, H., Xu, F., Kotalwar, J., Wijnands, I., Mishra,
              M., and Z. Zhang, "PIM Signaling Through BIER Core", Work
              in Progress, Internet-Draft, draft-ietf-bier-pim-
              signaling-12, 25 July 2021,
              <https://www.ietf.org/archive/id/draft-ietf-bier-pim-
              signaling-12.txt>.

   [I-D.ietf-bier-te-arch]
              Eckert, T., Cauchie, G., and M. Menth, "Tree Engineering
              for Bit Index Explicit Replication (BIER-TE)", Work in
              Progress, Internet-Draft, draft-ietf-bier-te-arch-09, 30
              October 2020, <https://www.ietf.org/internet-drafts/draft-
              ietf-bier-te-arch-09.txt>.

   [I-D.ietf-isis-yang-isis-cfg]
              Litkowski, S., Yeung, D., Lindem, A., Zhang, J., and L.
              Lhotka, "YANG Data Model for IS-IS Protocol", Work in
              Progress, Internet-Draft, draft-ietf-isis-yang-isis-cfg-
              42, 15 October 2019, <https://www.ietf.org/archive/id/
              draft-ietf-isis-yang-isis-cfg-42.txt>.

   [I-D.ietf-ospf-yang]
              Yeung, D., Qu, Y., Zhang, J., Chen, I., and A. Lindem,
              "YANG Data Model for OSPF Protocol", Work in Progress,
              Internet-Draft, draft-ietf-ospf-yang-29, 17 October 2019,
              <https://www.ietf.org/archive/id/draft-ietf-ospf-yang-
              29.txt>.




Zhang, et al.           Expires 26 February 2022               [Page 38]


Internet-Draft          Multicast YANG Data Model            August 2021


   [I-D.ietf-pim-sr-p2mp-policy]
              Voyer, D., Filsfils, C., Parekh, R., Bidgoli, H., and Z.
              Zhang, "Segment Routing Point-to-Multipoint Policy", Work
              in Progress, Internet-Draft, draft-ietf-pim-sr-p2mp-
              policy-02, 19 February 2021,
              <https://www.ietf.org/archive/id/draft-ietf-pim-sr-p2mp-
              policy-02.txt>.

   [I-D.ietf-pim-yang]
              Liu, X., McAllister, P., Peter, A., Sivakumar, M., Liu,
              Y., and F. Hu, "A YANG Data Model for Protocol Independent
              Multicast (PIM)", Work in Progress, Internet-Draft, draft-
              ietf-pim-yang-17, 19 May 2018,
              <https://www.ietf.org/archive/id/draft-ietf-pim-yang-
              17.txt>.

   [I-D.ietf-rift-rift]
              Sharma, A., Thubert, P., Rijsman, B., and D. Afanasiev,
              "RIFT: Routing in Fat Trees", Work in Progress, Internet-
              Draft, draft-ietf-rift-rift-13, 12 July 2021,
              <https://www.ietf.org/archive/id/draft-ietf-rift-rift-
              13.txt>.

   [I-D.szcl-mboned-redundant-ingress-failover]
              Shepherd, G., Zhang, Z., Liu, Y., and Y. Cheng, "Multicast
              Redundant Ingress Router Failover", Work in Progress,
              Internet-Draft, draft-szcl-mboned-redundant-ingress-
              failover-01, 8 July 2021,
              <https://www.ietf.org/archive/id/draft-szcl-mboned-
              redundant-ingress-failover-01.txt>.

   [RFC3688]  Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688,
              DOI 10.17487/RFC3688, January 2004,
              <https://www.rfc-editor.org/info/rfc3688>.

   [RFC4541]  Christensen, M., Kimball, K., and F. Solensky,
              "Considerations for Internet Group Management Protocol
              (IGMP) and Multicast Listener Discovery (MLD) Snooping
              Switches", RFC 4541, DOI 10.17487/RFC4541, May 2006,
              <https://www.rfc-editor.org/info/rfc4541>.

   [RFC6037]  Rosen, E., Ed., Cai, Y., Ed., and IJ. Wijnands, "Cisco
              Systems' Solution for Multicast in BGP/MPLS IP VPNs",
              RFC 6037, DOI 10.17487/RFC6037, October 2010,
              <https://www.rfc-editor.org/info/rfc6037>.






Zhang, et al.           Expires 26 February 2022               [Page 39]


Internet-Draft          Multicast YANG Data Model            August 2021


   [RFC7348]  Mahalingam, M., Dutt, D., Duda, K., Agarwal, P., Kreeger,
              L., Sridhar, T., Bursell, M., and C. Wright, "Virtual
              eXtensible Local Area Network (VXLAN): A Framework for
              Overlaying Virtualized Layer 2 Networks over Layer 3
              Networks", RFC 7348, DOI 10.17487/RFC7348, August 2014,
              <https://www.rfc-editor.org/info/rfc7348>.

   [RFC7637]  Garg, P., Ed. and Y. Wang, Ed., "NVGRE: Network
              Virtualization Using Generic Routing Encapsulation",
              RFC 7637, DOI 10.17487/RFC7637, September 2015,
              <https://www.rfc-editor.org/info/rfc7637>.

   [RFC8407]  Bierman, A., "Guidelines for Authors and Reviewers of
              Documents Containing YANG Data Models", BCP 216, RFC 8407,
              DOI 10.17487/RFC8407, October 2018,
              <https://www.rfc-editor.org/info/rfc8407>.

   [RFC8639]  Voit, E., Clemm, A., Gonzalez Prieto, A., Nilsen-Nygaard,
              E., and A. Tripathy, "Subscription to YANG Notifications",
              RFC 8639, DOI 10.17487/RFC8639, September 2019,
              <https://www.rfc-editor.org/info/rfc8639>.

   [RFC8641]  Clemm, A. and E. Voit, "Subscription to YANG Notifications
              for Datastore Updates", RFC 8641, DOI 10.17487/RFC8641,
              September 2019, <https://www.rfc-editor.org/info/rfc8641>.

   [RFC8926]  Gross, J., Ed., Ganga, I., Ed., and T. Sridhar, Ed.,
              "Geneve: Generic Network Virtualization Encapsulation",
              RFC 8926, DOI 10.17487/RFC8926, November 2020,
              <https://www.rfc-editor.org/info/rfc8926>.

   [RFC8966]  Chroboczek, J. and D. Schinazi, "The Babel Routing
              Protocol", RFC 8966, DOI 10.17487/RFC8966, January 2021,
              <https://www.rfc-editor.org/info/rfc8966>.

Appendix A.  Data Tree Example

   This section contains an example of an instance data tree in JSON
   encoding [RFC7951], containing configuration data.

   The configuration example:










Zhang, et al.           Expires 26 February 2022               [Page 40]


Internet-Draft          Multicast YANG Data Model            August 2021


              {
                "ietf-multicast-model:multicast-model":{
                  "multicast-keys":[
                    {
                      "vpn-rd":"0:65532:4294967292",
                      "source-address":"*",
                      "group-address":"234.232.203.84",
                      "mac-address": "00:00:5e:00:53:01",
                      "vni-value":0,
                      "multicast-overlay":{
                        "vni-type":"nvgre",
                        "ingress-egress":{
                          "ingress-nodes":[
                            {
                              "ingress-node":"146.150.100.0"
                            }
                          ],
                          "egress-nodes":[
                            {
                              "egress-node":"110.141.168.0"
                            }
                          ]
                        }
                      },
                      "multicast-transport":{
                        "type": "ietf-multicast-model:bier",
                        "bier":{
                          "sub-domain":0,
                          "bitstringlength":256,
                          "set-identifier":0
                        }
                      },
                      "multicast-underlay":{
                        "type": "ietf-multicast-model:ospf",
                        "ospf":{
                          "topology":"2"
                        }
                      }
                    }
                  ]
                }
              }


Authors' Addresses






Zhang, et al.           Expires 26 February 2022               [Page 41]


Internet-Draft          Multicast YANG Data Model            August 2021


   Zheng Zhang
   ZTE Corporation
   China

   Email: zhang.zheng@zte.com.cn


   Cui(Linda) Wang
   Individual
   Australia

   Email: lindawangjoy@gmail.com


   Ying Cheng
   China Unicom
   Beijing
   China

   Email: chengying10@chinaunicom.cn


   Xufeng Liu
   Volta Networks

   Email: xufeng.liu.ietf@gmail.com


   Mahesh Sivakumar
   Juniper networks
   1133 Innovation Way
   Sunnyvale, CALIFORNIA 94089,
   United States of America

   Email: sivakumar.mahesh@gmail.com
















Zhang, et al.           Expires 26 February 2022               [Page 42]