



Internet Engineering Task Force (IETF)                 M. Boucadair, Ed.
Request for Comments: 9836                                        Orange
Category: Standards Track                                     R. Roberts
ISSN: 2070-1721                                                  Juniper
                                                              S. Barguil
                                                                   Nokia
                                                     O. Gonzalez de Dios
                                                              Telefonica
                                                          September 2025


  A YANG Data Model for Augmenting VPN Service and Network Models with
                          Attachment Circuits

Abstract

   This document defines a YANG data model, referred to as the "AC Glue"
   model, to augment the LxVPN Service Model (LxSM) and LxVPN Network
   Model (LxNM) with references to attachment circuits (ACs).  The AC
   Glue model enables a provider to associate Layer 2/3 VPN (LxVPN)
   services with the underlying AC infrastructure, thereby facilitating
   consistent provisioning and management of new or existing ACs in
   conjunction with LxVPN services.  Specifically, by introducing an
   integrated approach to AC and LxVPN management, this model supports
   Attachment Circuit as a Service (ACaaS) and provides a standardized
   mechanism for aligning AC/VPN requests with the network
   configurations required to deliver them.

Status of This Memo

   This is an Internet Standards Track document.

   This document is a product of the Internet Engineering Task Force
   (IETF).  It represents the consensus of the IETF community.  It has
   received public review and has been approved for publication by the
   Internet Engineering Steering Group (IESG).  Further information on
   Internet Standards is available in Section 2 of RFC 7841.

   Information about the current status of this document, any errata,
   and how to provide feedback on it may be obtained at
   https://www.rfc-editor.org/info/rfc9836.

Copyright Notice

   Copyright (c) 2025 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.  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 Revised BSD License text as described in Section 4.e of the
   Trust Legal Provisions and are provided without warranty as described
   in the Revised BSD License.

Table of Contents

   1.  Introduction
   2.  Conventions and Definitions
   3.  Relationship to Other AC Data Models
   4.  Sample Uses of the Data Models
     4.1.  ACs Terminated by One or Multiple Customer Edges (CEs)
     4.2.  Separate AC Provisioning from Actual VPN Service
           Provisioning
   5.  Module Tree Structure
   6.  The AC Glue ("ietf-ac-glue") YANG Module
   7.  Security Considerations
   8.  IANA Considerations
   9.  References
     9.1.  Normative References
     9.2.  Informative References
   Appendix A.  Examples
     A.1.  A Service AC Reference Within the VPN Network Access
     A.2.  Network and Service AC References
   Acknowledgments
   Authors' Addresses

1.  Introduction

   To facilitate data transfer within the provider network, it is
   assumed that the appropriate setup is provisioned over the links that
   connect customer termination points and a provider network (usually
   via a Provider Edge (PE)), allowing data to be successfully exchanged
   over these links.  The required setup is referred to in this document
   as an attachment circuit (AC), while the underlying link is referred
   to as "bearer".

   The document specifies a YANG module ("ietf-ac-glue", Section 6) that
   updates existing service and network Virtual Private Network (VPN)
   modules with the required information to bind specific services to
   ACs that are created using the AC service model [RFC9834].
   Specifically, the following modules are augmented:

   *  The L2VPN Service Model (L2SM) [RFC8466]

   *  The L3VPN Service Model (L3SM) [RFC8299]

   *  The L2VPN Network Model (L2NM) [RFC9291]

   *  The L3VPN Network Model (L3NM) [RFC9182]

   Likewise, the document augments the L2NM and L3NM with references to
   the ACs that are managed using the AC network model [RFC9835].

   This approach allows operators to separate AC provisioning from
   actual VPN service provisioning.  Refer to Section 4.2 for more
   discussion.

   The YANG data model in this document conforms to the Network
   Management Datastore Architecture (NMDA) defined in [RFC8342].

   Examples to illustrate the use of the "ietf-ac-glue" module are
   provided in Appendix A.

2.  Conventions and Definitions

   The meanings of the symbols in the YANG tree diagrams are defined in
   [RFC8340].

   This document uses terms defined in [RFC9834].

   LxSM refers to both the L2SM and the L3SM.

   LxNM refers to both the L2NM and the L3NM.

   The following terms are used in the module's prefixes:

   ac:  Attachment circuit

   ntw:  Network

   ref:  Reference

   svc:  Service

   The names of data nodes are prefixed using the prefix associated with
   the corresponding imported YANG module as shown in Table 1:

         +===========+================+==========================+
         | Prefix    | Module         | Reference                |
         +===========+================+==========================+
         | ac-svc    | ietf-ac-svc    | Section 6.2 of [RFC9834] |
         +-----------+----------------+--------------------------+
         | ac-ntw    | ietf-ac-ntw    | [RFC9835]                |
         +-----------+----------------+--------------------------+
         | l2nm      | ietf-l2vpn-ntw | [RFC9291]                |
         +-----------+----------------+--------------------------+
         | l2vpn-svc | ietf-l2vpn-svc | [RFC8466]                |
         +-----------+----------------+--------------------------+
         | l3nm      | ietf-l3vpn-ntw | [RFC9182]                |
         +-----------+----------------+--------------------------+
         | l3vpn-svc | ietf-l3vpn-svc | [RFC8299]                |
         +-----------+----------------+--------------------------+

               Table 1: Modules and Their Associated Prefixes

3.  Relationship to Other AC Data Models

   Figure 1 depicts the relationship between the various AC data models:

   *  "ietf-ac-common" [RFC9833]

   *  "ietf-bearer-svc" (Section 6.1 of [RFC9834])

   *  "ietf-ac-svc" (Section 6.2 of [RFC9834])

   *  "ietf-ac-ntw" [RFC9835]

   *  "ietf-ac-glue" (Section 6)

                               ietf-ac-common
                                ^     ^     ^
                                |     |     |
                     .----------'     |     '----------.
                     |                |                |
                     |                |                |
               ietf-ac-svc <--- ietf-bearer-svc        |
                  ^    ^                               |
                  |    |                               |
                  |    '------------------------ ietf-ac-ntw
                  |                                    ^
                  |                                    |
                  |                                    |
                  '------------ ietf-ac-glue ----------'

               X --> Y: X imports Y

                          Figure 1: AC Data Models

   The "ietf-ac-common" module is imported by the "ietf-bearer-svc",
   "ietf-ac-svc", and "ietf-ac-ntw" modules.  Bearers managed using the
   "ietf-bearer-svc" module may be referenced by service ACs managed
   using the "ietf-ac-svc" module.  Similarly, a bearer managed using
   the "ietf-bearer-svc" module may list the set of ACs that use that
   bearer.  To facilitate correlation between an AC service request and
   the actual AC provisioned in the network, "ietf-ac-ntw" leverages the
   AC references exposed by the "ietf-ac-svc" module.  Furthermore, to
   bind Layer 2 VPN (L2VPN) or Layer 3 VPN (L3VPN) services with ACs,
   the "ietf-ac-glue" module augments the LxSM and LxNM with AC service
   references exposed by the "ietf-ac-svc" module and AC network
   references exposed by the "ietf-ac-ntw" module.

4.  Sample Uses of the Data Models

4.1.  ACs Terminated by One or Multiple Customer Edges (CEs)

   Figure 2 depicts two target topology flavors that involve ACs.  These
   topologies have the following characteristics:

   *  A Customer Edge (CE) can be either a physical device or a logical
      entity.  Such logical entity is typically a software component
      (e.g., a virtual service function that is hosted within the
      provider's network or a third-party infrastructure).  A CE is seen
      by the network as a peer Service Attachment Point (SAP) [RFC9408].

   *  CEs may be either dedicated to one single connectivity service or
      host multiple connectivity services (e.g., CEs with roles of
      service functions [RFC7665]).

   *  A network provider may bind a single AC to one or multiple peer
      SAPs (e.g., CE1 and CE2 are tagged as peer SAPs for the same AC).
      For example, and as discussed in [RFC4364], multiple CEs can be
      attached to a PE over the same AC.  This scenario is typically
      implemented when the Layer 2 infrastructure between the CE and the
      network is a multipoint service.

   *  A single CE may terminate multiple ACs, which can be associated
      with the same bearer or distinct bearers (e.g., CE4).

   *  Customers may request protection schemes in which the ACs
      associated with their endpoints are terminated by the same PE
      (e.g., CE3), distinct PEs (e.g., CE4), etc.  The network provider
      uses this request to decide where to terminate the AC in the
      service provider network and also whether to enable specific
      capabilities (e.g., Virtual Router Redundancy Protocol (VRRP)).

                             .--------------------.
                             |                    |
       .------.              |                   .--.  (b1)   .-----.
      |       +----.         |                   |  +---AC---+      |
      |  CE1  |    |         |                   |PE+---AC---+  CE3 |
      '------'     |       .--.                  '--'  (b2)  '-----'
                   +---AC--+PE|     Network       |
       .------.    |       '--'                  .--.  (b3)   .-----.
      |       |    |         |                   |  +---AC---+      |
      |  CE2  +----'         |                   |PE+---AC---+  CE4 |
      '------'               |                   '--'  (b3)  '---+-'
                             |          .--.      |              |
                             '----------+PE+------'              |
                                        '--'                     |
                                         |                       |
                                         '-----------AC----------'
      (bx) = bearer Id x

                         Figure 2: Examples of ACs

   These ACs can be referenced when creating VPN services.  Refer to the
   examples provided in Appendix A to illustrate how VPN services can be
   bound to ACs.

4.2.  Separate AC Provisioning from Actual VPN Service Provisioning

   The procedure to provision a service in a service provider network
   may depend on the practices adopted by a service provider.  This
   includes the flow put in place for the provisioning of advanced
   network services and how they are bound to an AC.  For example, a
   single AC may be used to host multiple connectivity services (e.g.,
   L2VPN ("ietf-l2vpn-svc"), L3VPN ("ietf-l3vpn-svc"), Network Slice
   Service ("ietf-network-slice-service")).  In order to avoid service
   interference and redundant information in various locations, a
   service provider may expose an interface to manage ACs network-wide
   using the modules in [RFC9834].  Customers can request for an AC
   ("ietf-ac-svc") to be put in place and then refer to that AC when
   requesting VPN services that are bound to the AC ("ietf-ac-glue").

   Also, internal references ("ietf-ac-ntw") used within a service
   provider network to implement ACs can be used by network controllers
   to glue the L2NM ("ietf-l2vpn-ntw") or the L3NM ("ietf-l3vpn-ntw")
   services with relevant ACs.

   Figure 3 shows the positioning of the AC models in the overall
   service delivery process.

                                .-------------.
                               |   Customer    |
                                '------+------'
               Customer Service Models |
       ietf-l2vpn-svc, ietf-l3vpn-svc, | ietf-network-slice-service,
            ietf-ac-svc, ietf-ac-glue, | and ietf-bearer-svc
                                .------+------.
                               |    Service    |
                               | Orchestration |
                                '------+------'
                Network Models         |
       ietf-l2vpn-ntw, ietf-l3vpn-ntw, | ietf-sap-ntw, ietf-ac-glue,
                and ietf-ac-ntw        |
                                .------+------.
                               |   Network     |
                               | Orchestration |
                                '------+------'
         Network Configuration Model   |
                           .-----------+-----------.
                           |                       |
                   .-------+-----.         .-------+-----.
                  |    Domain     |       |     Domain    |
                  | Orchestration |       | Orchestration |
                   '--+--------+-'         '-------+-----'
       Device         |        |                   |
       Configuration  |        |                   |
       Models         |        |                   |
                  .---+---.    |                   |
                 | Config  |   |                   |
                 | Manager |   |                   |
                  '---+---'    |                   |
                      |        |                   |
                   NETCONF/CLI.......................
                      |        |                   |
                    .--------------------------------.
       .---. Bearer |                                | Bearer  .---.
      |CE1 +--------+            Network             +--------+ CE2|
      '---'         |                                |        '---'
                    '--------------------------------'
       Site A                                                  Site B

                  Figure 3: An Example of AC Models Usage

5.  Module Tree Structure

   [RFC8299] specifies that a 'site-network-access' attachment is
   achieved through a 'bearer' with an 'ip-connection' on top.  From
   that standpoint, a 'site-network-access' is mapped to an AC with both
   Layer 2 and Layer 3 properties per [RFC9834].  [RFC8466] specifies
   that a 'site-network-access' represents a logical Layer 2 connection
   to a site.  A 'site-network-access' can thus be mapped to an AC with
   Layer 2 properties [RFC9834].  Similarly, 'vpn-network-access'
   defined in both [RFC9182] and [RFC9291] is mapped to an AC per
   [RFC9834] or [RFC9835].

   As such, ACs created using the "ietf-ac-svc" module [RFC9834] can be
   referenced in other VPN-related modules (e.g., LxSM and LxNM).  Also,
   ACs managed using the "ietf-ac-ntw" module [RFC9835] can be
   referenced in VPN-related network modules (mainly, the LxNM).  The
   required augmentations to that aim are shown in Figure 4.

   module: ietf-ac-glue

     augment /l2vpn-svc:l2vpn-svc/l2vpn-svc:sites/l2vpn-svc:site
               /l2vpn-svc:site-network-accesses:
       +--rw ac-svc-ref*   ac-svc:attachment-circuit-reference
     augment /l2vpn-svc:l2vpn-svc/l2vpn-svc:sites/l2vpn-svc:site
               /l2vpn-svc:site-network-accesses
               /l2vpn-svc:site-network-access:
       +--rw ac-svc-ref?  ac-svc:attachment-circuit-reference {ac-glue}?
     augment /l3vpn-svc:l3vpn-svc/l3vpn-svc:sites/l3vpn-svc:site
               /l3vpn-svc:site-network-accesses:
       +--rw ac-svc-ref*   ac-svc:attachment-circuit-reference
     augment /l3vpn-svc:l3vpn-svc/l3vpn-svc:sites/l3vpn-svc:site
               /l3vpn-svc:site-network-accesses
               /l3vpn-svc:site-network-access:
       +--rw ac-svc-ref?  ac-svc:attachment-circuit-reference {ac-glue}?
     augment /l2nm:l2vpn-ntw/l2nm:vpn-services/l2nm:vpn-service
               /l2nm:vpn-nodes/l2nm:vpn-node/l2nm:vpn-network-accesses:
       +--rw ac-svc-ref*   ac-svc:attachment-circuit-reference
       +--rw ac-ntw-ref* [ac-ref]
          +--rw ac-ref         leafref
          +--rw node-ref?      leafref
          +--rw network-ref?   -> /nw:networks/network/network-id
     augment /l2nm:l2vpn-ntw/l2nm:vpn-services/l2nm:vpn-service
               /l2nm:vpn-nodes/l2nm:vpn-node/l2nm:vpn-network-accesses
               /l2nm:vpn-network-access:
       +--rw ac-svc-ref?  ac-svc:attachment-circuit-reference {ac-glue}?
       +--rw ac-ntw-ref {ac-glue}?
          +--rw ac-ref?        leafref
          +--rw node-ref?      leafref
          +--rw network-ref?   -> /nw:networks/network/network-id
     augment /l3nm:l3vpn-ntw/l3nm:vpn-services/l3nm:vpn-service
               /l3nm:vpn-nodes/l3nm:vpn-node/l3nm:vpn-network-accesses:
       +--rw ac-svc-ref*   ac-svc:attachment-circuit-reference
       +--rw ac-ntw-ref* [ac-ref]
          +--rw ac-ref         leafref
          +--rw node-ref?      leafref
          +--rw network-ref?   -> /nw:networks/network/network-id
     augment /l3nm:l3vpn-ntw/l3nm:vpn-services/l3nm:vpn-service
               /l3nm:vpn-nodes/l3nm:vpn-node/l3nm:vpn-network-accesses
               /l3nm:vpn-network-access:
       +--rw ac-svc-ref?  ac-svc:attachment-circuit-reference {ac-glue}?
       +--rw ac-ntw-ref {ac-glue}?
          +--rw ac-ref?        leafref
          +--rw node-ref?      leafref
          +--rw network-ref?   -> /nw:networks/network/network-id

                      Figure 4: AC Glue Tree Structure

   When an AC is referenced within a specific network access, that AC
   information takes precedence over any overlapping information that is
   also enclosed for this network access.

      |  This approach is consistent with the design in [YANG-NSS] where
      |  an AC service reference, called 'ac-svc-ref', is used to
      |  indicate the names of AC services.  As per [YANG-NSS], when
      |  both 'ac-svc-ref' and the attributes of 'attachment-circuits'
      |  are defined, the 'ac-svc-ref' takes precedence.

   The "ietf-ac-glue" module includes provisions to reference ACs within
   or outside a VPN network access to accommodate deployment contexts
   where an AC reference may be created before or after a VPN instance
   is created.  Appendix A.1 illustrates how an AC reference can be
   included as part of a specific VPN network access, while Appendix A.2
   shows how AC references can be indicated outside individual VPN
   network access entries.

6.  The AC Glue ("ietf-ac-glue") YANG Module

   This modules augments the L2SM [RFC8466], the L3SM [RFC8299], the
   L2NM [RFC9291], and the L3NM [RFC9182].

   This module uses references defined in [RFC9834] and [RFC9835].

   <CODE BEGINS> file "ietf-ac-glue@2025-09-29.yang"
   module ietf-ac-glue {
     yang-version 1.1;
     namespace "urn:ietf:params:xml:ns:yang:ietf-ac-glue";
     prefix ac-glue;

     import ietf-l3vpn-svc {
       prefix l3vpn-svc;
       reference
         "RFC 8299: YANG Data Model for L3VPN Service Delivery";
     }
     import ietf-l2vpn-svc {
       prefix l2vpn-svc;
       reference
         "RFC 8466: A YANG Data Model for Layer 2 Virtual Private
                    Network (L2VPN) Service Delivery";
     }
     import ietf-l3vpn-ntw {
       prefix l3nm;
       reference
         "RFC 9182: A YANG Network Data Model for Layer 3 VPNs";
     }
     import ietf-l2vpn-ntw {
       prefix l2nm;
       reference
         "RFC 9291: A YANG Network Data Model for Layer 2 VPNs";
     }
     import ietf-ac-svc {
       prefix ac-svc;
       reference
         "RFC 9834: YANG Data Models for Bearers and Attachment
                    Circuits as a Service (ACaaS)";
     }
     import ietf-ac-ntw {
       prefix ac-ntw;
       reference
         "RFC 9835: A Network YANG Data Model for Attachment Circuits";
     }

     organization
       "IETF OPSAWG (Operations and Management Area Working Group)";
     contact
       "WG Web:   <https://datatracker.ietf.org/wg/opsawg/>
        WG List:  <mailto:opsawg@ietf.org>

        Editor:   Mohamed Boucadair
                  <mailto:mohamed.boucadair@orange.com>
        Author:   Richard Roberts
                  <mailto:rroberts@juniper.net>
        Author:   Samier Barguil
                  <mailto:ssamier.barguil_giraldo@nokia.com>
        Author:   Oscar Gonzalez de Dios
                  <mailto:oscar.gonzalezdedios@telefonica.com>";
     description
       "This YANG module defines a YANG data model for augmenting the
        LxSM and the LxNM with AC references.

        Copyright (c) 2025 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 Revised 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 9836; see the
        RFC itself for full legal notices.";

     revision 2025-09-29 {
       description
         "Initial revision.";
       reference
         "RFC 9836: A YANG Data Model for Augmenting VPN Service
                    and Network Models with Attachment Circuits";
     }

     feature ac-glue {
       description
         "The VPN implementation supports binding a specific VPN
          network access or site access to an AC.";
     }

     grouping single-ac-svc-ref {
       description
         "A grouping with a single reference to a service AC.";
       leaf ac-svc-ref {
         type ac-svc:attachment-circuit-reference;
         description
           "A reference to the AC as exposed at the service that was
            provisioned using the ACaaS module.";
       }
     }

     grouping single-ac-svc-ntw-ref {
       description
         "A grouping with single AC references.";
       leaf ac-svc-ref {
         type ac-svc:attachment-circuit-reference;
         description
           "A reference to the AC as exposed at the service that was
            provisioned using the ACaaS module.";
       }
       container ac-ntw-ref {
         description
           "A reference to the AC that was provisioned using the AC
            network module.";
         uses ac-ntw:attachment-circuit-reference;
       }
     }

     grouping ac-svc-ref {
       description
         "A set of service-specific AC-related data.";
       leaf-list ac-svc-ref {
         type ac-svc:attachment-circuit-reference;
         description
           "A reference to the AC as exposed at the service that was
            provisioned using the ACaaS module.";
       }
     }

     grouping ac-svc-ntw-ref {
       description
         "A set of AC-related data.";
       leaf-list ac-svc-ref {
         type ac-svc:attachment-circuit-reference;
         description
           "A reference to the AC as exposed at the service that was
            provisioned using the ACaaS module.";
       }
       list ac-ntw-ref {
         key "ac-ref";
         description
           "A reference to the AC that was provisioned using the AC
            network module.";
         uses ac-ntw:attachment-circuit-reference;
       }
     }

     augment "/l2vpn-svc:l2vpn-svc"
           + "/l2vpn-svc:sites/l2vpn-svc:site"
           + "/l2vpn-svc:site-network-accesses" {
       description
         "Augments VPN site network accesses with AC provisioning
          details.  Concretely, it binds a site to a set of ACs with
          Layer 2 properties that were created using the ACaaS module.";
       uses ac-svc-ref;
     }

     augment "/l2vpn-svc:l2vpn-svc"
           + "/l2vpn-svc:sites/l2vpn-svc:site"
           + "/l2vpn-svc:site-network-accesses"
           + "/l2vpn-svc:site-network-access" {
       if-feature "ac-glue";
       description
         "Augments VPN site network access with AC provisioning
          details.  Concretely, it glues a 'site-network-access'
          to an AC with Layer 2 properties that was created using the
          ACaaS module.

          The ACaaS information takes precedence over any overlapping
          information that is also provided for a site network access.";
       uses single-ac-svc-ref;
     }

     augment "/l3vpn-svc:l3vpn-svc"
           + "/l3vpn-svc:sites/l3vpn-svc:site"
           + "/l3vpn-svc:site-network-accesses" {
       description
         "Augments VPN site network accesses with AC provisioning
          details.  Concretely, it binds a site to a set of ACs with
          both Layer 2 and Layer 3 properties that were created using
          the ACaaS module.";
       uses ac-svc-ref;
     }

     augment "/l3vpn-svc:l3vpn-svc"
           + "/l3vpn-svc:sites/l3vpn-svc:site"
           + "/l3vpn-svc:site-network-accesses"
           + "/l3vpn-svc:site-network-access" {
       if-feature "ac-glue";
       description
         "Augments VPN site network access with AC provisioning
          details.  Concretely, it glues a 'site-network-access' to an
          AC with both Layer 2 and Layer 3 properties that was created
          using the ACaaS module.

          The ACaaS information takes precedence over any overlapping
          information that is also provided for a site network access.";
       uses single-ac-svc-ref;
     }

     augment "/l2nm:l2vpn-ntw/l2nm:vpn-services/l2nm:vpn-service"
           + "/l2nm:vpn-nodes/l2nm:vpn-node"
           + "/l2nm:vpn-network-accesses" {
       description
         "Augments VPN network accesses with both service and network
          AC provisioning details.  Concretely, it binds a site to (1)
          a set of ACs with Layer 2 properties that were created using
          the ACaaS module and (2) a set of ACs with Layer 2 properties
          that were provisioned using the AC network model.";
       uses ac-svc-ntw-ref;
     }

     augment "/l2nm:l2vpn-ntw/l2nm:vpn-services/l2nm:vpn-service"
           + "/l2nm:vpn-nodes/l2nm:vpn-node"
           + "/l2nm:vpn-network-accesses"
           + "/l2nm:vpn-network-access" {
       if-feature "ac-glue";
       description
         "Augments VPN network access with service and network
          references to an AC.  Concretely, it glues a VPN network
          access to (1) an AC with Layer 2 properties
          that was created using the ACaaS module and (2) an AC with
          Layer 2 properties that was created using the AC network
          module.

          The AC service and network information takes precedence over
          any overlapping information that is also provided for a VPN
          network access.";
       uses single-ac-svc-ntw-ref;
     }

     augment "/l3nm:l3vpn-ntw/l3nm:vpn-services/l3nm:vpn-service"
           + "/l3nm:vpn-nodes/l3nm:vpn-node"
           + "/l3nm:vpn-network-accesses" {
       description
         "Augments VPN network accesses with both service and network
          AC provisioning details.  Concretely, it binds a site to (1)
          a set of ACs with both Layer 2 and Layer 3  properties that
          were created using the ACaaS module and (2) a set of ACs with
          both Layer 2 and Layer 3 properties that were provisioned
          using the AC network model.";
       uses ac-svc-ntw-ref;
     }

     augment "/l3nm:l3vpn-ntw/l3nm:vpn-services/l3nm:vpn-service"
           + "/l3nm:vpn-nodes/l3nm:vpn-node"
           + "/l3nm:vpn-network-accesses"
           + "/l3nm:vpn-network-access" {
       if-feature "ac-glue";
       description
         "Augments VPN network access with service and network
          references to an AC.  Concretely, it glues a VPN network
          access to (1) an AC with both Layer 2 and Layer 3 properties
          that was created using the ACaaS module and (2) an AC with
          both Layer 2 and Layer 3 properties that was created using the
          AC network module.

          The AC service and network information takes precedence over
          any overlapping information that is also provided for a VPN
          network access.";
       uses single-ac-svc-ntw-ref;
     }
   }
   <CODE ENDS>

7.  Security Considerations

   This section is modeled after the template described in Section 3.7
   of [YANG-GUIDELINES].

   The "ietf-ac-common" YANG module defines a data model that is
   designed to be accessed via YANG-based management protocols, such as
   NETCONF [RFC6241] and RESTCONF [RFC8040].  These protocols have to
   use a secure transport layer (e.g., SSH [RFC4252], TLS [RFC8446], and
   QUIC [RFC9000]) and have to use mutual authentication.

   The Network Configuration Access Control Model (NACM) [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).  All writable data nodes are likely to be reasonably
   sensitive or vulnerable in some network environments.  Write
   operations (e.g., edit-config) and delete operations to these data
   nodes without proper protection or authentication can have a negative
   effect on network operations.  The following subtrees and data nodes
   have particular sensitivities/vulnerabilities:

   'ac-svc-ref' and 'ac-ntw-ref':  An attacker who is able to access
      network nodes can undertake various attacks, such as deleting a
      running VPN service, interrupting all the traffic of a client.
      Specifically, an attacker may modify (including delete) the ACs
      that are bound to a running service, leading to malfunctioning of
      the service and therefore to Service Level Agreement (SLA)
      violations.  Such activity can be detected by adequately
      monitoring and tracking network configuration changes.

   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.  Specifically, the following
   subtrees and data nodes have particular sensitivities/
   vulnerabilities:

   'ac-svc-ref' and 'ac-ntw-ref':  These references do not expose
      privacy-related information per se; however, 'ac-svc-ref' may be
      used to track the set of VPN instances in which a given customer
      is involved.

      Note that, unlike 'ac-svc-ref', 'ac-ntw-ref' is unique within the
      scope of a node and may multiplex many peer CEs.

8.  IANA Considerations

   IANA has registered the following URI in the "ns" subregistry within
   the "IETF XML Registry" [RFC3688]:

   URI:  urn:ietf:params:xml:ns:yang:ietf-ac-glue
   Registrant Contact:  The IESG.
   XML:  N/A; the requested URI is an XML namespace.

   IANA has registered the following YANG module in the "YANG Module
   Names" registry [RFC6020] within the "YANG Parameters" registry
   group:

   Name:  ietf-ac-glue
   Maintained by IANA?  N
   Namespace:  urn:ietf:params:xml:ns:yang:ietf-ac-glue
   Prefix:  ac-glue
   Reference:  RFC 9836

9.  References

9.1.  Normative References

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

   [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>.

   [RFC8299]  Wu, Q., Ed., Litkowski, S., Tomotaki, L., and K. Ogaki,
              "YANG Data Model for L3VPN Service Delivery", RFC 8299,
              DOI 10.17487/RFC8299, January 2018,
              <https://www.rfc-editor.org/info/rfc8299>.

   [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>.

   [RFC8466]  Wen, B., Fioccola, G., Ed., Xie, C., and L. Jalil, "A YANG
              Data Model for Layer 2 Virtual Private Network (L2VPN)
              Service Delivery", RFC 8466, DOI 10.17487/RFC8466, October
              2018, <https://www.rfc-editor.org/info/rfc8466>.

   [RFC9182]  Barguil, S., Gonzalez de Dios, O., Ed., Boucadair, M.,
              Ed., Munoz, L., and A. Aguado, "A YANG Network Data Model
              for Layer 3 VPNs", RFC 9182, DOI 10.17487/RFC9182,
              February 2022, <https://www.rfc-editor.org/info/rfc9182>.

   [RFC9291]  Boucadair, M., Ed., Gonzalez de Dios, O., Ed., Barguil,
              S., and L. Munoz, "A YANG Network Data Model for Layer 2
              VPNs", RFC 9291, DOI 10.17487/RFC9291, September 2022,
              <https://www.rfc-editor.org/info/rfc9291>.

   [RFC9834]  Boucadair, M., Ed., Roberts, R., Ed., Gonzalez de Dios,
              O., Barguil, S., and B. Wu, "YANG Data Models for Bearers
              and Attachment Circuits as a Service (ACaaS)", RFC 9834,
              DOI 10.17487/RFC9834, September 2025,
              <https://www.rfc-editor.org/info/rfc9834>.

   [RFC9835]  Boucadair, M., Ed., Roberts, R., Gonzalez de Dios, O.,
              Barguil, S., and B. Wu, "A Network YANG Data Model for
              Attachment Circuits", RFC 9835, DOI 10.17487/RFC9835,
              September 2025, <https://www.rfc-editor.org/info/rfc9835>.

9.2.  Informative References

   [RFC4252]  Ylonen, T. and C. Lonvick, Ed., "The Secure Shell (SSH)
              Authentication Protocol", RFC 4252, DOI 10.17487/RFC4252,
              January 2006, <https://www.rfc-editor.org/info/rfc4252>.

   [RFC4364]  Rosen, E. and Y. Rekhter, "BGP/MPLS IP Virtual Private
              Networks (VPNs)", RFC 4364, DOI 10.17487/RFC4364, February
              2006, <https://www.rfc-editor.org/info/rfc4364>.

   [RFC4664]  Andersson, L., Ed. and E. Rosen, Ed., "Framework for Layer
              2 Virtual Private Networks (L2VPNs)", RFC 4664,
              DOI 10.17487/RFC4664, September 2006,
              <https://www.rfc-editor.org/info/rfc4664>.

   [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>.

   [RFC7665]  Halpern, J., Ed. and C. Pignataro, Ed., "Service Function
              Chaining (SFC) Architecture", RFC 7665,
              DOI 10.17487/RFC7665, October 2015,
              <https://www.rfc-editor.org/info/rfc7665>.

   [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>.

   [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>.

   [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>.

   [RFC9000]  Iyengar, J., Ed. and M. Thomson, Ed., "QUIC: A UDP-Based
              Multiplexed and Secure Transport", RFC 9000,
              DOI 10.17487/RFC9000, May 2021,
              <https://www.rfc-editor.org/info/rfc9000>.

   [RFC9408]  Boucadair, M., Ed., Gonzalez de Dios, O., Barguil, S., Wu,
              Q., and V. Lopez, "A YANG Network Data Model for Service
              Attachment Points (SAPs)", RFC 9408, DOI 10.17487/RFC9408,
              June 2023, <https://www.rfc-editor.org/info/rfc9408>.

   [RFC9833]  Boucadair, M., Ed., Roberts, R., Ed., Gonzalez de Dios,
              O., Barguil, S., and B. Wu, "A Common YANG Data Model for
              Attachment Circuits", RFC 9833, DOI 10.17487/RFC9833,
              September 2025, <https://www.rfc-editor.org/info/rfc9833>.

   [YANG-GUIDELINES]
              Bierman, A., Boucadair, M., Ed., and Q. Wu, "Guidelines
              for Authors and Reviewers of Documents Containing YANG
              Data Models", Work in Progress, Internet-Draft, draft-
              ietf-netmod-rfc8407bis-22, 14 January 2025,
              <https://datatracker.ietf.org/doc/html/draft-ietf-netmod-
              rfc8407bis-22>.

   [YANG-NSS] Wu, B., Dhody, D., Rokui, R., Saad, T., and J. Mullooly,
              "A YANG Data Model for the RFC 9543 Network Slice
              Service", Work in Progress, Internet-Draft, draft-ietf-
              teas-ietf-network-slice-nbi-yang-25, 9 May 2025,
              <https://datatracker.ietf.org/doc/html/draft-ietf-teas-
              ietf-network-slice-nbi-yang-25>.

Appendix A.  Examples

A.1.  A Service AC Reference Within the VPN Network Access

   Let us consider the example depicted in Figure 5, which is inspired
   from Section 2.1 of [RFC4664].  Each PE is servicing two CEs.  Let us
   also assume that the service references to identify ACs with these
   CEs are shown in Figure 5.

          .----.                                            .----.
         |     |  AC1                                AC2   |     |
         | CE1 |--+ 2001:db8:100::1     2001:db8:200::1 +--| CE2 |
         |     |  |    .-----.   .-----.     .-----.    |  |     |
         '----'   +----|---- |   |  P  |     | ----+----+  '----'
                       |VPWS\----|-----|-----|/VPWS|
                       | PE1 |===|=====|=====| PE2 |
                       |    /|---|-----|-----|\\   |
          .----.  +----|---- |   |     |     | ----|----+   .----.
         |     |  |    '-----'   '-----'     '-----'    |  |     |
         | CE3 |--+                                     +--| CE4 |
         |     |  AC3                                 AC4  |     |
         '----'                                            '----'

                      Figure 5: VPWS Topology Example

   As shown in Figure 6, the service AC references can be explicitly
   indicated in the L2NM query for the realization of the Virtual
   Private Wire Service (VPWS) (Section 3.1.1 of [RFC4664]).

   =============== NOTE: '\' line wrapping per RFC 8792 ================

   {
      "ietf-l2vpn-ntw:l2vpn-ntw":{
         "vpn-services":{
            "vpn-service":[
               {
                  "vpn-id":"vpws12345",
                  "vpn-description":"Sample VPWS with AC service \
                                                            references",
                  "customer-name":"customer-12345",
                  "vpn-type":"ietf-vpn-common:vpws",
                  "bgp-ad-enabled":true,
                  "signaling-type":"ietf-vpn-common:ldp-signaling",
                  "global-parameters-profiles":{
                     "global-parameters-profile":[
                        {
                           "profile-id":"simple-profile",
                           "local-autonomous-system":65550,
                           "rd-auto":{
                              "auto":[
                                 null
                              ]
                           },
                           "vpn-target":[
                              {
                                 "id":1,
                                 "route-targets":[
                                    {
                                       "route-target":"0:65535:1"
                                    }
                                 ],
                                 "route-target-type":"both"
                              }
                           ]
                        }
                     ]
                  },
                  "vpn-nodes":{
                     "vpn-node":[
                        {
                           "vpn-node-id":"pe1",
                           "ne-id":"2001:db8:100::1",
                           "active-global-parameters-profiles":{
                              "global-parameters-profile":[
                                 {
                                    "profile-id":"simple-profile"
                                 }
                              ]
                           },
                           "bgp-auto-discovery":{
                              "vpn-id":"587"
                           },
                           "signaling-option":{
                              "advertise-mtu":true,
                              "ldp-or-l2tp":{
                                 "saii":1,
                                 "remote-targets":[
                                    {
                                       "taii":2
                                    }
                                 ],
                                 "t-ldp-pw-type":"ethernet"
                              }
                           },
                           "vpn-network-accesses":{
                              "vpn-network-access":[
                                 {
                                    "id":"1/1/1.1",
                                    "interface-id":"1/1/1",
                                    "description":"Interface to CE1",
                                    "active-vpn-node-profile":"simple-\
                                                               profile",
                                    "status":{
                                       "admin-status":{
                                          "status":"ietf-vpn-common:\
                                                               admin-up"
                                       },
                                       "ietf-ac-glue:ac-svc-ref":"AC1"
                                    }
                                 },
                                 {
                                    "id":"1/1/3.1",
                                    "interface-id":"1/1/3",
                                    "description":"Interface to CE3",
                                    "active-vpn-node-profile":"simple-\
                                                               profile",
                                    "status":{
                                       "admin-status":{
                                          "status":"ietf-vpn-common:\
                                                               admin-up"
                                       },
                                       "ietf-ac-glue:ac-svc-ref":"AC3"
                                    }
                                 }
                              ]
                           }
                        },
                        {
                           "vpn-node-id":"pe2",
                           "ne-id":"2001:db8:200::1",
                           "active-global-parameters-profiles":{
                              "global-parameters-profile":[
                                 {
                                    "profile-id":"simple-profile"
                                 }
                              ]
                           },
                           "bgp-auto-discovery":{
                              "vpn-id":"587"
                           },
                           "signaling-option":{
                              "advertise-mtu":true,
                              "ldp-or-l2tp":{
                                 "saii":2,
                                 "remote-targets":[
                                    {
                                       "taii":1
                                    }
                                 ],
                                 "t-ldp-pw-type":"ethernet"
                              }
                           },
                           "vpn-network-accesses":{
                              "vpn-network-access":[
                                 {
                                    "id":"2/1/2.1",
                                    "interface-id":"2/1/2",
                                    "description":"Interface to CE2",
                                    "active-vpn-node-profile":"simple-\
                                                               profile",
                                    "status":{
                                       "admin-status":{
                                          "status":"ietf-vpn-common:\
                                                               admin-up"
                                       },
                                       "ietf-ac-glue:ac-svc-ref":"AC2"
                                    }
                                 },
                                 {
                                    "id":"2/1/4.1",
                                    "interface-id":"2/1/4",
                                    "description":"Interface to CE4",
                                    "active-vpn-node-profile":"simple-\
                                                               profile",
                                    "status":{
                                       "admin-status":{
                                          "status":"ietf-vpn-common:\
                                                               admin-up"
                                       },
                                       "ietf-ac-glue:ac-svc-ref":"AC4"
                                    }
                                 }
                              ]
                           }
                        }
                     ]
                  }
               }
            ]
         }
      }
   }

       Figure 6: Example of VPWS Creation with AC Service References

A.2.  Network and Service AC References

   Let us consider the example depicted in Figure 7 with two customer
   termination points (CE1 and CE2).  Let us also assume that the
   bearers to attach these CEs to the service provider network are
   already in place.  References to identify these bearers are shown in
   Figure 7.

                   .-----.   .--------------.   .-----.
        .---.      | PE1 +===+              +===+ PE2 |       .---.
       | CE1+------+"450"|   |     MPLS     |   |"451"+------+ CE2|
       '---'    ^  '-----'   |              |   '-----'   ^  '---'
                |            |     Core     |             |
           Bearer:1234       '--------------'         Bearer:5678

                         Figure 7: Topology Example

   The AC service model [RFC9834] can be used by the provider to manage
   and expose the ACs over existing bearers as shown in Figure 8.

   {
     "ietf-ac-svc:attachment-circuits": {
       "ac-group-profile": [
         {
           "name": "an-ac-profile",
           "l2-connection": {
             "encapsulation": {
               "type": "ietf-vpn-common:dot1q",
               "dot1q": {
                 "tag-type": "ietf-vpn-common:c-vlan",
                 "cvlan-id": 550
               }
             }
           },
           "service": {
             "mtu": 1550,
             "svc-pe-to-ce-bandwidth": {
               "bandwidth": [
                 {
                   "bw-type": "ietf-vpn-common:bw-per-port",
                   "cir": "20480000"
                 }
               ]
             },
             "svc-ce-to-pe-bandwidth": {
               "bandwidth": [
                 {
                   "bw-type": "ietf-vpn-common:bw-per-port",
                   "cir": "20480000"
                 }
               ]
             },
             "qos": {
               "qos-profiles": {
                 "qos-profile": [
                   {
                     "profile": "QoS_Profile_A",
                     "direction": "ietf-vpn-common:both"
                   }
                 ]
               }
             }
           }
         }
       ],
       "ac": [
         {
           "name": "ac-1",
           "description": "First attachment",
           "ac-group-profile": [
             "an-ac-profile"
           ],
           "l2-connection": {
             "bearer-reference": "1234"
           }
         },
         {
           "name": "ac-2",
           "description": "Second attachment",
           "ac-group-profile": [
             "an-ac-profile"
           ],
           "l2-connection": {
             "bearer-reference": "5678"
           }
         }
       ]
     }
   }

                     Figure 8: ACs Created Using ACaaS

   Let us now consider that the customer wants to request a Virtual
   Private LAN Service (VPLS) instance between the sites as shown in
   Figure 9.

                   |----------  VPLS "1543" ----------|

                   .-----.   .--------------.   .-----.
        .---.  AC1 | PE1 +===+              +===+ PE2 |  AC2  .---.
       | CE1+------+"450"|   |     MPLS     |   |"451"+------+ CE2|
       '---'    ^  '-----'   |              |   '-----'   ^  '---'
                |            |     Core     |             |
           Bearer:1234       '--------------'         Bearer:5678

                         Figure 9: Example of VPLS

   To that aim, existing ACs are referenced during the creation of the
   VPLS instance using the L2NM [RFC9291] and the "ietf-ac-glue" module
   as shown in Figure 10.

   {
     "ietf-l2vpn-ntw:l2vpn-ntw": {
       "vpn-services": {
         "vpn-service": [
           {
             "vpn-id": "1543",
             "vpn-name": "CORPO-EXAMPLE",
             "customer-name": "EXAMPLE",
             "vpn-type": "ietf-vpn-common:vpls",
             "vpn-service-topology": "ietf-vpn-common:hub-spoke",
             "bgp-ad-enabled": false,
             "signaling-type": "ietf-vpn-common:ldp-signaling",
             "global-parameters-profiles": {
               "global-parameters-profile": [
                 {
                   "profile-id": "simple-profile",
                   "ce-vlan-preservation": true,
                   "ce-vlan-cos-preservation": true
                 }
               ]
             },
             "vpn-nodes": {
               "vpn-node": [
                 {
                   "vpn-node-id": "450",
                   "ne-id": "2001:db8:5::1",
                   "role": "ietf-vpn-common:hub-role",
                   "status": {
                     "admin-status": {
                       "status": "ietf-vpn-common:admin-up"
                     }
                   },
                   "active-global-parameters-profiles": {
                     "global-parameters-profile": [
                       {
                         "profile-id": "simple-profile"
                       }
                     ]
                   },
                   "signaling-option": {
                     "ldp-or-l2tp": {
                       "t-ldp-pw-type": "vpls-type",
                       "pw-peer-list": [
                         {
                           "peer-addr": "2001:db8:50::1",
                           "vc-id": "1543"
                         }
                       ]
                     }
                   },
                   "vpn-network-accesses": {
                     "ietf-ac-glue:ac-svc-ref": ["ac-1"]
                   }
                 },
                 {
                   "vpn-node-id": "451",
                   "ne-id": "2001:db8:50::1",
                   "role": "ietf-vpn-common:spoke-role",
                   "status": {
                     "admin-status": {
                       "status": "ietf-vpn-common:admin-up"
                     }
                   },
                   "active-global-parameters-profiles": {
                     "global-parameters-profile": [
                       {
                         "profile-id": "simple-profile"
                       }
                     ]
                   },
                   "signaling-option": {
                     "ldp-or-l2tp": {
                       "t-ldp-pw-type": "vpls-type",
                       "pw-peer-list": [
                         {
                           "peer-addr": "2001:db8:5::1",
                           "vc-id": "1543"
                         }
                       ]
                     }
                   },
                   "vpn-network-accesses": {
                     "ietf-ac-glue:ac-svc-ref": ["ac-2"]
                   }
                 }
               ]
             }
           }
         ]
       }
     }
   }

        Figure 10: Example of a VPLS Request Using L2NM and AC Glue
                               (Message Body)

   Note that before implementing the VPLS instance creation request, the
   provider service orchestrator may first check if the VPLS service can
   be provided to the customer using the target delivery locations.  The
   orchestrator uses the SAP model [RFC9408] as exemplified in
   Figure 11.  This example assumes that the query concerns only PE1.  A
   similar query can be issued for PE2.

   {
      "ietf-sap-ntw:service":[
         {
            "service-type":"ietf-vpn-common:vpls",
            "sap":[
               {
                  "sap-id":"sap#1",
                  "peer-sap-id":[
                     "ce-1"
                  ],
                  "description":"A parent SAP",
                  "attachment-interface":"GE0/6/1",
                  "interface-type":"ietf-sap-ntw:phy",
                  "role":"ietf-sap-ntw:uni",
                  "allows-child-saps":true,
                  "sap-status":{
                     "status":"ietf-vpn-common:op-up"
                  }
               }
            ]
         }
      ]
   }

             Figure 11: Example of SAP Response (Message Body)

   The response in Figure 11 indicates that the VPLS service can be
   delivered to CE1.  The "ietf-ac-ntw" module [RFC9835] can be also
   used to access AC-related details that are bound to the target SAP
   (Figure 12).

   {
      "ietf-sap-ntw:service":[
         {
            "service-type":"ietf-vpn-common:vpls",
            "sap":[
               {
                  "sap-id":"sap#1",
                  "peer-sap-id":[
                     "ce-1"
                  ],
                  "description":"A parent SAP",
                  "attachment-interface":"GE0/6/1",
                  "interface-type":"ietf-sap-ntw:phy",
                  "role":"ietf-sap-ntw:uni",
                  "allows-child-saps":true,
                  "sap-status":{
                     "status":"ietf-vpn-common:op-up"
                  }
               },
               {
                  "sap-id":"sap#11",
                  "description":"A child SAP",
                  "parent-termination-point":"GE0/6/4",
                  "attachment-interface":"GE0/6/4.2",
                  "interface-type":"ietf-sap-ntw:logical",
                  "encapsulation-type":"ietf-vpn-common:vlan-type",
                  "sap-status":{
                     "status":"ietf-vpn-common:op-up"
                  },
                  "ietf-ac-ntw:ac":[
                     {
                        "ac-ref":"ac-1",
                        "node-ref":"example:pe2",
                        "network-ref":"example:an-id"
                     }
                  ]
               }
            ]
         }
      ]
   }

     Figure 12: Example of AC Network Response with SAP (Message Body)

   The provisioned AC at PE1 can be retrieved using the AC network model
   [RFC9835] as depicted in Figure 13.

   {
      "ietf-ac-ntw:ac":[
         {
            "name":"ac-11",
            "svc-ref":"ac-1",
            "peer-sap-id":[
               "ce-1"
            ],
            "status":{
               "admin-status":{
                  "status":"ietf-vpn-common:admin-up"
               },
               "oper-status":{
                  "status":"ietf-vpn-common:op-up"
               }
            },
            "l2-connection":{
               "encapsulation":{
                  "encap-type":"ietf-vpn-common:dot1q",
                  "dot1q":{
                     "tag-type":"ietf-vpn-common:c-vlan",
                     "cvlan-id":550
                  }
               },
               "bearer-reference":"1234"
            },
            "service":{
               "mtu":1550,
               "svc-pe-to-ce-bandwidth":{
                  "bandwidth":[
                     {
                        "bw-type": "ietf-vpn-common:bw-per-port",
                        "cir":"20480000"
                     }
                  ]
               },
               "svc-ce-to-pe-bandwidth":{
                  "bandwidth":[
                     {
                        "bw-type": "ietf-vpn-common:bw-per-port",
                        "cir":"20480000"
                     }
                  ]
               },
               "qos":{
                  "qos-profiles":{
                     "qos-profile":[
                        {
                           "qos-profile-ref":"QoS_Profile_A",
                           "network-ref":"example:an-id",
                           "direction":"ietf-vpn-common:both"
                        }
                     ]
                  }
               }
            }
         }
      ]
   }

          Figure 13: Example of AC Network Response (Message Body)

Acknowledgments

   Thanks to Bo Wu and Qin Wu for the review and comments.

   Thanks to Martin Björklund for the YANG Doctors review, Gyan Mishra
   for the RTGDIR review, Ron Bonica for the OPSDIR review, Reese
   Enghardt for the GENART review, and Prachi Jain for the SECDIR
   review.

   Thanks to Mahesh Jethanandani for the AD review.

   Thanks to Gunter Van de Velde for the IESG review.

Authors' Addresses

   Mohamed Boucadair (editor)
   Orange
   Email: mohamed.boucadair@orange.com


   Richard Roberts
   Juniper
   Email: rroberts@juniper.net


   Samier Barguil
   Nokia
   Email: samier.barguil_giraldo@nokia.com


   Oscar Gonzalez de Dios
   Telefonica
   Email: oscar.gonzalezdedios@telefonica.com
