Internet-Draft Inventory Topology Mapping June 2026
Wu, et al. Expires 27 December 2026 [Page]
Workgroup:
Network Inventory YANG
Internet-Draft:
draft-ietf-ivy-network-inventory-topology-08
Published:
Intended Status:
Standards Track
Expires:
Authors:
B. Wu, Ed.
Huawei
M. Boucadair
Orange
C. Zhou
China Mobile
Q. Wu
Huawei

A YANG Network Data Model for Inventory Topology Mapping

Abstract

This document defines a YANG data model that extends the network topology data model (RFC 8345) to map network topologies with inventories. The data model introduces the "inventory-topology" network type and augmentations for physical entity mappings and capabilities, which may be used by any overlay network topology for service provisioning validation, network maintenance, and capacity planning.

Discussion Venues

This note is to be removed before publishing as an RFC.

Discussion of this document takes place on the Network Inventory YANG Working Group mailing list (inventory-yang@ietf.org), which is archived at https://mailarchive.ietf.org/arch/browse/inventory-yang/.

Source for this draft and an issue tracker can be found at https://github.com/ietf-ivy-wg/network-inventory-topology.

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 27 December 2026.

▲

Table of Contents

1. Introduction

[I-D.ietf-ivy-network-inventory-yang] defines the base network inventory model to aggregate the inventory data of Network Elements (NEs). This data includes identification of these NEs and their hardware, firmware, and software components. Examples of inventory hardware components could be rack, shelf, slot, board, or physical port. Examples of inventory software components could be platform Operating System (OS), software-modules, bios, or boot-loader [I-D.ietf-ivy-network-inventory-software].

In order to ease navigation between inventory and network topologies, this document extends the network topology data model [RFC8345] for network inventory mapping: "ietf-network-inventory-topology" (Section 5).

Similar to the base inventory data model [I-D.ietf-ivy-network-inventory-yang], the network inventory topology does not make any assumption about involved NEs and their roles in topologies. As such, the mapping data model can be applied independent of the network type (optical local loops, access network, core network, etc.) and application.

Therefore, this YANG data model can be used to represent a physical network instance at the lowest underlay abstraction level, as shown in Section 4.4.9 of [RFC8345]. Alternatively, it can be used in conjunction with existing network topology models, such as [RFC9408], [RFC8944], [RFC8346], [RFC8795], and [I-D.ietf-ccamp-otn-topo-yang], when they contain nodes, links, or termination points belonging to the lowest underlay level.

1.1. Editorial Note (To be removed by RFC Editor)

  • Note to the RFC Editor: This section is to be removed prior to publication.

This document contains placeholder values that need to be replaced with finalized values at the time of publication. This note summarizes all of the substitutions that are needed.

Please apply the following replacements:

2. Conventions and Definitions

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

This document uses terms defined in [I-D.ietf-ivy-network-inventory-yang].

The document adheres to the folding conventions in [RFC8792].

3. Sample Use Cases of the Data Model

3.1. Determine Available Resources of Service Attachment Points (SAPs)

The inventory topology data model provides a physical port reference (port-ref) that enables correlation between logical topology entities and physical inventory components. During service provisioning, the SAP's parent-termination-point can be associated with the inventory topology's port-ref to locate the underlying physical resource.

Figure 1 illustrates the query interactions. During service provisioning, the orchestrator can issue a query using the SAP data model (e.g., obtaining a list of SAPs across multiple PEs as shown in Appendix A of [RFC9408]), and then uses the inventory topology data model to identify the physical port underlying each candidate SAP. Specifically, the "parent-termination-point" of a SAP is mapped to the corresponding "port-ref" in the inventory topology, allowing the orchestrator to locate the physical resource. The orchestrator can then consult other relevant topology models (e.g., [RFC8795]) to verify whether the identified port has adequate capacity for the requested service.

If the physical port underlying a candidate SAP has insufficient resources (e.g., port speed fully utilized), the orchestrator can select an alternate SAP that maps to a different port with adequate capacity. If no alternative SAP is available, the orchestrator flags the request for manual intervention, providing the operator with precise inventory information about the bottleneck (e.g., "Port GE0/6/1 on NE-PE1 is at 95% utilization"). The resource constraint can also feed into a "what-if" analysis (see Section 3.3) to evaluate hardware upgrades or alternative underlay paths.

Customer Customer Service request (e.g., L3SM and L2SM) Service Orchestration (1a) Query SAPs (1b) Map SAP to physical port via SAP Data Model via Inventory Topology Network Controller Network
Figure 1: An Example Usage of Network Inventory Topology

3.2. Multi-layer Network Navigation

A multi-layer network encompasses multiple layers (e.g., Layer 2 and Layer 3, or Optical Transport Network (OTN) and Wavelength Division Multiplexing (WDM) layers).

A multi-layer network topology comprises nodes, links, and termination points that can belong to different layers.

A multi-layer network can contain multiple types of topological elements: physical elements (associated with an inventory element) or logical elements (associated with topology elements in the underlay layer).

The topology models support navigation across the different layers, down to the physical layer, as defined in Section 4.4.9 of [RFC8345]. The navigation between the physical layer and the network inventory is outside the scope of the topology models and is addressed in this document.

3.3. "What-if" Scenarios

[I-D.irtf-nmrg-network-digital-twin-arch] defines Network Digital Twin (NDT) as a virtual representation of the physical network. Such representation is meant to be used to analyze, diagnose, emulate, and then manage the physical network based on data, models, and interfaces.

[I-D.ietf-nmop-simap-concept] defines Service and Infrastructure Maps (SIMAP) as an abstraction model that provides a unified view of both service and infrastructure information, enabling correlation between service requirements and underlying resource capabilities.

Both architectures require accurate mapping between logical network topology and physical inventory as a foundational data layer. This model provides the essential physical resource information to such systems, enabling them to perform accurate "what-if" analysis (e.g., impact prediction of hardware End-of-Life, path re-optimization under resource constraints, service availability assessment).

4. Module Tree Structure

An overview of the structure of the "ietf-network-inventory-topology" module is shown in Figure 2.

module: ietf-network-inventory-topology

  augment /nw:networks/nw:network/nw:network-types:
    +--rw inventory-topology!
  augment /nw:networks/nw:network/nw:node:
    +--rw inventory-mapping-attributes
       +--rw ne-ref?   nwi:ne-ref
  augment /nw:networks/nw:network/nt:link:
    +--rw inventory-mapping-attributes
       +--rw link-type?   identityref
  augment /nw:networks/nw:network/nw:node/nt:termination-point:
    +--rw inventory-mapping-attributes
    |  +--rw ne-ref?     nwi:ne-ref
    |  +--rw port-ref?   leafref
    +--ro port-breakout!
       +--ro breakout-channel* [channel-id]
          +--ro channel-id    uint16
Figure 2: The Structure of the Network Inventory Mapping Data Model

The module augments the "ietf-network-topology" module as follows:

Inventory mapping attributes for nodes, and termination points:

The corresponding containers augments the topology module with the references to the base network inventory

4.2. Port-Breakout Capability

High-density Ethernet ports (e.g., 400 Gb/s DR4) can be split into multiple independent lower-speed channels. The breakout channels represent the intrinsic capability of the port to be partitioned, regardless of whether the port is currently configured as a trunk or as a breakout port.

A trunk port is associated with exactly one physical interface. A breakout port is a port that is decomposed into two or more physical interfaces; those interfaces may run at the same or different speeds and may consume the same or a different number of breakout channels.

The container "port-breakout" is added under the termination-point augmentation. It lists the logical channels into which the single physical port can be divided. Only termination-points whose parent port is breakout-capable need to instantiate the container; otherwise the container is omitted, keeping the topology model minimal for the common non-breakout case.

Breakout channel is an atomic resource element obtained by partitioning a breakout port. One physical interface may be associated with one or more breakout channels, but one breakout channel MUST NOT be associated with more than one physical interface. Appendix B provides example configurations.

It is assumed that a port which supports breakout can be configured either as a trunk port or as a breakout port. Interface channelisation (e.g., VLAN sub-interfaces) is outside the scope of this document and is addressed by the Layer 2 network topology model [RFC8944].

5. Network Inventory Topology YANG Module

This module augments the Network Topology module defined in [RFC8345].

This module imports the base network inventory [I-D.ietf-ivy-network-inventory-yang].

<CODE BEGINS> file "ietf-network-inventory-topology@2026-06-25.yang"

module ietf-network-inventory-topology {
  yang-version 1.1;
  namespace
    "urn:ietf:params:xml:ns:yang:ietf-network-inventory-topology";
  prefix nwit;

  import ietf-network {
    prefix nw;
    reference
      "RFC 8345: A YANG Data Model for Network Topologies,
                 Section 4.1";
  }
  import ietf-network-topology {
    prefix nt;
    reference
      "RFC 8345: A YANG Data Model for Network Topologies,
                 Section 4.2";
  }
  import ietf-network-inventory {
    prefix nwi;
    reference
      "RFC AAAA: A YANG Data Model for Network Inventory";
  }

  organization
    "IETF Network Inventory YANG (ivy) Working Group";
  contact
    "WG Web:   <https://datatracker.ietf.org/wg/ivy>
     WG List:  IVY <mailto:inventory-yang@ietf.org>

     Editor: Bo Wu
             <lana.wubo@huawei.com>
     Editor: Mohamed Boucadair
             <mohamed.boucadair@orange.com>
     Author: Cheng Zhou
             <zhouchengyjy@chinamobile.com>
     Author: Qin Wu
             <bill.wu@huawei.com>";
  description
    "This YANG module defines a YANG module for network
     topology and inventory mapping.

     Copyright (c) 2026 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).

     All revisions of IETF and IANA published modules can be found
     at the YANG Parameters registry group
     (https://www.iana.org/assignments/yang-parameters).

     This version of this YANG module is part of RFC XXXX; see
     the RFC itself for full legal notices.";

  revision 2026-06-25 {
    description
      "Initial revision.";
    reference
      "RFC XXXX: A Network Data Model for Inventory Topology
                 Mapping";
  }

  identity link-type {
    description
      "Base identity for classifying the physical media type of a
       link at the inventory topology layer.  Specialized inventory
       models are expected to define derived identities for specific
       media, e.g., fiber, copper, or wireless.";
  }

  identity copper {
    base link-type;
    description
      "Copper-based physical link.";
  }

  identity fiber {
    base link-type;
    description
      "Fiber-based physical link.";
  }

  identity coax {
    base link-type;
    description
      "Coaxial cable-based physical link.";
  }

  identity microwave {
    base link-type;
    description
      "Microwave-based wireless link.
       Detailed microwave radio attributes are defined in the
       microwave topology data model.";
    reference
      "RFC 9656: A YANG Data Model for Microwave Topology";
  }

  identity wlan {
    base link-type;
    description
      "IEEE 802.11 wireless link.";
  }

  identity unknown {
    base link-type;
    description
      "The link media type is unknown or could not be determined.
       This identity is used as a fallback when the physical medium
       cannot be classified into any of the other defined types.";
  }

  identity leased-fiber {
    base fiber;
    description
      "Leased fiber link.  The physical medium is fiber, but the link
       is provided by a third-party operator.  Detailed physical
       attributes are typically not visible to the lessee.";
  }

  // Main blocks

  augment "/nw:networks/nw:network/nw:network-types" {
    description
      "Introduces a new network type for inventory topology
       mapping.";
    container inventory-topology {
      presence
        "Indicates a physical network topology, containing
         physical-layer attributes including inventory mapping, port
         breakout capabilities, and link media types.";
      description
        "Container for the inventory-topology network type.
         When present, it signals that the network contains
         physical-layer augmentations as defined in this module.
         This network type is intended to serve as the underlay
         for logical network topologies (Layer 2, Layer 3,
         Traffic Engineering (TE), etc.).";
    }
  }

  augment "/nw:networks/nw:network/nw:node" {
    when '../nw:network-types/nwit:inventory-topology';
    description
      "Augments the network topology node with inventory mapping
       attributes. This enables correlation between the logical node
       and its physical network element.";
    container inventory-mapping-attributes {
      presence
        "If present, it indicates this is a physical node, which
         maps to a network element. If not present, it indicates it
         is an abstract node.";
      description
        "Container for inventory mapping attributes of a node.";
      leaf ne-ref {
        type nwi:ne-ref;
        description
          "Reference to the NE in the inventory that corresponds to
           this topology node.

           This reference establishes a 1:1 mapping between the
           logical node and its physical NE.";
      }
    }
  }

  augment "/nw:networks/nw:network/nt:link" {
    when '../nw:network-types/nwit:inventory-topology';
    description
      "Augments the network topology link with inventory-related
       attributes.";
    container inventory-mapping-attributes {
      presence "Indicates a physical link, at the lowest underlay
                abstraction level.";
      description
        "Container for inventory-related attributes of a link.

         This container provides lightweight media classification.
         The link-type indicates which specialized inventory model
         contains detailed resource information:

         - Wired media (fiber, copper): passive network inventory
         - Wireless media (microwave, Wi-Fi): wireless-specific
           inventory

           Detailed inventory references may be added in future
           modules.";
      leaf link-type {
        type identityref {
          base link-type;
        }
        description
          "Classification of the link media type at the topology
           layer.

           The base identity 'link-type' is extensible. Examples
           of derived identities include 'copper', 'fiber',
           'coax', 'microwave', and 'wlan'.

           This leaf serves as a lightweight discriminator.  When
           the value is 'microwave', detailed microwave link
           attributes are defined in the microwave topology data
           model. Wired media (e.g., fiber, copper, or coax) may
           be detailed in a passive network inventory data
           model.";
      }
    }
  }

  augment "/nw:networks/nw:network/nw:node/nt:termination-point" {
    when '../../nw:network-types/nwit:inventory-topology';
    description
      "Augments the TP with inventory mapping and port breakout.";
    container inventory-mapping-attributes {
      presence
        "If present, it indicates this is a physical termination
         point (TP), which maps to a port component. If not present,
         it indicates it is a logical TP.";
      description
        "Container for inventory mapping attributes of a TP.";
      uses nwi:port-ref {
        refine "port-ref" {
          description
            "Reference to the physical port component in the
             network inventory. This reference establishes a 1:1
             mapping between the logical TP and its physical port
             component.";
        }
      }
    }
    // breakout channels (lightweight, per physical port)
    container port-breakout {
      presence "Indicates the port supports channel breakout.";
      config false;
      description
        "Breakout capability of the physical port represented by
         this TP. One TP maps to one physical port; channels are
         listed here. This container is present only when the
         underlying hardware supports partitioning the port into
         multiple independent channels (e.g., 400G to 4x100G).";
      list breakout-channel {
        key "channel-id";
        description
          "List of breakout channels available on this port.
           Each entry represents an independent lane or sub-port
           that can be used for channelized interfaces.";
        leaf channel-id {
          type uint16;
          description
            "Unique identifier for the breakout channel within the
             scope of the parent port.";
        }
      } // breakout-channel
    } // port-breakout
  }
}

<CODE ENDS>

6. Operational Considerations

This model enables a network controller to report discovered network topology and inventory information. Automatic discovery serves as the primary mechanism, with selective configuration capabilities provided for scenarios where discovery is not feasible.

For typical operations such as service provisioning and network planning, the model offers read-only query access to authoritative mappings between logical topology and physical inventory. The inventory-mapping-attributes containers are defined as read-write (config true) to accommodate cases where automatic discovery is not possible, including:

In these cases, the operator manually configures the mapping to maintain accurate topology-to-inventory correlation.

The following nodes are read-only (config false) as they represent hardware-determined state:

port-breakout:

Hardware capability determined by physical port characteristics

7. Security Considerations

This section is modeled after the template described in Section 3.7.1 of [RFC9907].

The "ietf-network-inventory-topology" YANG module defines a data model that is designed to be accessed via YANG-based management protocols, such as Network Configuration (NETCONF) [RFC6241] and RESTCONF [RFC8040]. These YANG-based management (1) have to use a secure transport layer (e.g., Secure Shell (SSH) [RFC4252], TLS [I-D.ietf-tls-rfc8446bis], and QUIC {{?RFC9000]) and (2) 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 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:

'ne-ref', 'port-ref', 'link-type': These nodes are sensitive as they establish the mapping between logical topology and physical inventory. Unauthorized modification could lead to incorrect resource allocation or service disruption.

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:

'ne-ref': The references may be used to track the set of network elements. While read-only, they may reveal network infrastructure details.

'port-breakout': This node exposes hardware capabilities.

8. IANA Considerations

IANA is requested to register the following URI in the "ns" subregistry within the "IETF XML Registry" [RFC3688]:

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

IANA is requested to register the following YANG module in the "YANG Module Names" registry [RFC6020] within the "YANG Parameters" registry group:

   Name:  ietf-network-inventory-topology
   Maintained by IANA?  N
   Namespace:  urn:ietf:params:xml:ns:yang:ietf-network-inventory-topology
   Prefix:  nwit
   Reference:  RFC XXXX

9. References

9.1. Normative References

[I-D.ietf-ivy-network-inventory-yang]
Yu, C., Belotti, S., Bouquier, J., Peruzzini, F., and P. Bedard, "A Base YANG Data Model for Network Inventory", Work in Progress, Internet-Draft, draft-ietf-ivy-network-inventory-yang-18, , <https://datatracker.ietf.org/doc/html/draft-ietf-ivy-network-inventory-yang-18>.
[RFC3688]
Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688, DOI 10.17487/RFC3688, , <https://www.rfc-editor.org/rfc/rfc3688>.
[RFC6020]
Bjorklund, M., Ed., "YANG - A Data Modeling Language for the Network Configuration Protocol (NETCONF)", RFC 6020, DOI 10.17487/RFC6020, , <https://www.rfc-editor.org/rfc/rfc6020>.
[RFC8341]
Bierman, A. and M. Bjorklund, "Network Configuration Access Control Model", STD 91, RFC 8341, DOI 10.17487/RFC8341, , <https://www.rfc-editor.org/rfc/rfc8341>.
[RFC8345]
Clemm, A., Medved, J., Varga, R., Bahadur, N., Ananthakrishnan, H., and X. Liu, "A YANG Data Model for Network Topologies", RFC 8345, DOI 10.17487/RFC8345, , <https://www.rfc-editor.org/rfc/rfc8345>.

9.2. Informative References

[I-D.ietf-ccamp-otn-topo-yang]
Zheng, H., Busi, I., Liu, X., Belotti, S., and O. G. de Dios, "A YANG Data Model for Optical Transport Network Topology", Work in Progress, Internet-Draft, draft-ietf-ccamp-otn-topo-yang-21, , <https://datatracker.ietf.org/doc/html/draft-ietf-ccamp-otn-topo-yang-21>.
[I-D.ietf-ivy-network-inventory-software]
Wu, B., Zhou, C., Wu, Q., and M. Boucadair, "A YANG Network Data Model of Network Inventory Software Extensions", Work in Progress, Internet-Draft, draft-ietf-ivy-network-inventory-software-03, , <https://datatracker.ietf.org/doc/html/draft-ietf-ivy-network-inventory-software-03>.
[I-D.ietf-nmop-simap-concept]
Havel, O., Claise, B., de Dios, O. G., and T. Graf, "SIMAP: Concept, Requirements, and Use Cases", Work in Progress, Internet-Draft, draft-ietf-nmop-simap-concept-12, , <https://datatracker.ietf.org/doc/html/draft-ietf-nmop-simap-concept-12>.
[I-D.ietf-tls-rfc8446bis]
Rescorla, E., "The Transport Layer Security (TLS) Protocol Version 1.3", Work in Progress, Internet-Draft, draft-ietf-tls-rfc8446bis-14, , <https://datatracker.ietf.org/doc/html/draft-ietf-tls-rfc8446bis-14>.
[I-D.irtf-nmrg-network-digital-twin-arch]
Zhou, C., Yang, H., Duan, X., Lopez, D., Pastor, A., Wu, Q., Boucadair, M., and C. Jacquenet, "Network Digital Twin: Concepts and Reference Architecture", Work in Progress, Internet-Draft, draft-irtf-nmrg-network-digital-twin-arch-12, , <https://datatracker.ietf.org/doc/html/draft-irtf-nmrg-network-digital-twin-arch-12>.
[I-D.ygb-ivy-passive-network-inventory]
Guo, A., van caenegem, T., Davis, N., Tilocca, M., and B. Peters, "A YANG Data Model for Passive Network Inventory", Work in Progress, Internet-Draft, draft-ygb-ivy-passive-network-inventory-05, , <https://datatracker.ietf.org/doc/html/draft-ygb-ivy-passive-network-inventory-05>.
[RFC4252]
Ylonen, T. and C. Lonvick, Ed., "The Secure Shell (SSH) Authentication Protocol", RFC 4252, DOI 10.17487/RFC4252, , <https://www.rfc-editor.org/rfc/rfc4252>.
[RFC6241]
Enns, R., Ed., Bjorklund, M., Ed., Schoenwaelder, J., Ed., and A. Bierman, Ed., "Network Configuration Protocol (NETCONF)", RFC 6241, DOI 10.17487/RFC6241, , <https://www.rfc-editor.org/rfc/rfc6241>.
[RFC7951]
Lhotka, L., "JSON Encoding of Data Modeled with YANG", RFC 7951, DOI 10.17487/RFC7951, , <https://www.rfc-editor.org/rfc/rfc7951>.
[RFC8040]
Bierman, A., Bjorklund, M., and K. Watsen, "RESTCONF Protocol", RFC 8040, DOI 10.17487/RFC8040, , <https://www.rfc-editor.org/rfc/rfc8040>.
[RFC8340]
Bjorklund, M. and L. Berger, Ed., "YANG Tree Diagrams", BCP 215, RFC 8340, DOI 10.17487/RFC8340, , <https://www.rfc-editor.org/rfc/rfc8340>.
[RFC8346]
Clemm, A., Medved, J., Varga, R., Liu, X., Ananthakrishnan, H., and N. Bahadur, "A YANG Data Model for Layer 3 Topologies", RFC 8346, DOI 10.17487/RFC8346, , <https://www.rfc-editor.org/rfc/rfc8346>.
[RFC8792]
Watsen, K., Auerswald, E., Farrel, A., and Q. Wu, "Handling Long Lines in Content of Internet-Drafts and RFCs", RFC 8792, DOI 10.17487/RFC8792, , <https://www.rfc-editor.org/rfc/rfc8792>.
[RFC8795]
Liu, X., Bryskin, I., Beeram, V., Saad, T., Shah, H., and O. Gonzalez de Dios, "YANG Data Model for Traffic Engineering (TE) Topologies", RFC 8795, DOI 10.17487/RFC8795, , <https://www.rfc-editor.org/rfc/rfc8795>.
[RFC8944]
Dong, J., Wei, X., Wu, Q., Boucadair, M., and A. Liu, "A YANG Data Model for Layer 2 Network Topologies", RFC 8944, DOI 10.17487/RFC8944, , <https://www.rfc-editor.org/rfc/rfc8944>.
[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, , <https://www.rfc-editor.org/rfc/rfc9408>.
[RFC9656]
Mansfield, S., Ed., Ahlberg, J., Ye, M., Li, X., and D. Spreafico, "A YANG Data Model for Microwave Topology", RFC 9656, DOI 10.17487/RFC9656, , <https://www.rfc-editor.org/rfc/rfc9656>.
[RFC9907]
Bierman, A., Boucadair, M., Ed., and Q. Wu, "Guidelines for Authors and Reviewers of Documents Containing YANG Data Models", BCP 216, RFC 9907, DOI 10.17487/RFC9907, , <https://www.rfc-editor.org/rfc/rfc9907>.

Appendix B. JSON Example of an Multi-fibre Push On (MPO) Breakout-Channel Port

This appendix provides an example of a 400 Gb/s DR4 port that is physically implemented as four independent 100 Gb/s lanes (an MPO breakout). The lanes are exposed as breakout-channel entries so that the port can later be configured as either a single 400G trunk or four 100G breakout interfaces. The instance data below shows the minimal JSON encoding [RFC7951] of the "port-breakout" container for this port.

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

{
  "ietf-network-topology:networks": {
    "network": [
      {
        "network-id": "example:underlay-topology-400g",
        "node": [
          {
            "node-id": "example:n1",
            "termination-point": [
              {
                "tp-id": "example:400g-1/0/1",
                "ietf-network-inventory-topology:inventory-mapping-\
                                                       attributes": {
                  "ne-ref": "example:NE-1",
                  "port-ref": "example:port-1"
                },
                "ietf-network-inventory-topology:port-breakout": {
                  "breakout-channel": [
                    { "channel-id": 1 },
                    { "channel-id": 2 },
                    { "channel-id": 3 },
                    { "channel-id": 4 }
                  ]
                }
              }
            ]
          }
        ]
      }
    ]
  }
}

Acknowledgments

The authors wish to thank Italo Busi, Olga Havel, Aihua Guo, Oscar Gonzalez de Dios, and many others for their helpful comments and suggestions.

Contributors

Chaode Yu
Huawei

Authors' Addresses

Bo Wu (editor)
Huawei
Mohamed Boucadair
Orange
Cheng Zhou
China Mobile
Qin Wu
Huawei