]> Huawei

lana.wubo@huawei.com

Orange

mohamed.boucadair@orange.com

China Mobile

zhouchengyjy@chinamobile.com

Huawei

bill.wu@huawei.com

Operations and Management Network Inventory YANG Automation Network Digital Map Network Inventory Network Operation Network Topology This document defines a YANG data model to map the network inventory data with the topology data to form a base underlay network. The data model facilitates the correlation between the layer (e.g., Layer 2 or Layer 3) topology information and the inventory data of the underlay network for better service provisioning, network maintenance operations, and other assessment scenarios. Discussion Venues Discussion of this document takes place on the Network Inventory YANG Working Group mailing list (inventory-yang@ietf.org), which is archived at . Source for this draft and an issue tracker can be found at .

Introduction 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 . In order to ease navigation from (or to) inventory and network topologies, this document extends the network topology data model for network inventory mapping: "ietf-network-inventory-topology" (). This data model provides a mechanism for the correlation with existing network and topology data models, such as "A YANG Network Data Model for Service Attachment Points (SAPs)" , "A YANG Data Model for Layer 2 Network Topologies" , and "A YANG Data Model for Layer 3 Topologies" . Similar to the base inventory data model , the network inventory topology does not make any assumption about involved NEs and their roles in topologies. As such, the mapping model can be applied independent of the network type (optical local loops, access network, core network, etc.) and application.

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:

• XXXX --> the assigned RFC number for this I-D
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Conventions and Definitions The meanings of the symbols in the YANG tree diagrams are defined in . This document uses terms defined in .

Sample Use Cases of the Data Model

Determine Available Resources of Service Attachment Points (SAPs) The inventory topology data model can be used as a basis for correlating underlay information, such as physical port components. exemplifies this usage. During service provisioning, to check available physical port resources, the SAPs information can be associated with the underlay inventory information and interface information associated with the inventory topology, e.g., "parent-termination-point" of SAP Model can be associated with the "port-component-ref" of the inventory topology data model, which can be used to check the availability and capacity of physical ports.

An Example Usage of Network Inventory Topology

"What-if" Scenarios 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. The management system can use NDT to build multi-layer topology maps for networks and endpoints with relationship types and dependencies, and identify potential impacts on configuration management information from incidents, problems, and changes. More generally, the inventory topology data model can be used as part of the Service & Infrastructure Maps (SIMAP) . The inventory topology data model can, for example, be used to emulate several "what-if" scenarios such as the impact of End of Life (EOL) or depletion of a hardware component (chipset) on the network resilience and service availability.

Module Tree Structure An overview of the structure of the "ietf-network-inventory-topology" module is shown in .

The Structure of the Network Inventory Mapping Data Model /nw:networks/network/network-id {inventory-to-topology-navigate}? ]]>

The module defines two features "inventory-to-topology-navigate" and "topology-to-inventory-navigate" to control the navigation direction (from topology to inventory and vice versa). The module augments the "ietf-network-topology" module as follows:

• Inventory mapping attributes for nodes, links, and termination points: The corresponding containers augments the topology module with the references to the base network inventory The inventory topology model associates inventory data with overlay topologies. It can be used as the "supporting-networks" of SAP, Layer 2, or Layer 3 topologies.

Also, the "ietf-network-inventory-topology" module augments the "ietf-network-inventory" to add required references to navigate from the inventory to topologies ('node-ref' and 'network-ref').

Cable-Level Extensions: cable-name and link-type The dedicated passive-network inventory defined in draft-ygb-ivy-passive-network-inventory tracks and manages complex passive paths. For the simpler case of a direct point-to-point cable or fibre between two devices, this document adds lightweight leaves to the topology link:

• cable-name – optional asset identifier for a single physical cable (e.g., "CAB-2025-042").
• link-type – flexible-text hint such as "copper", "single-mode-fibre", "multi-mode-fibre", "coax".

When the link is formed by a single physical cable (e.g., one factory-terminated patch cord), both leaves may be populated. If the link is composed of several passive elements—such as jumpers, adapters, patch panels, or splice points—the cable-name leaf can be omitted, and the controller can derive the full path by traversing the TP → port-ref references and using the passive-inventory module.

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 breakout-config 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 .

Network Inventory Topology YANG Module This module augments the Network Topology . This module imports the base network inventory . WG List: Editor: Bo Wu Editor: Mohamed Boucadair Author: Cheng Zhou Author: Qin Wu "; description "This YANG module defines a YANG module for network topology and inventory mapping. 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). 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 2025-10-20 { description "Initial revision."; reference "RFC XXXX: A Network Data Model for Inventory Topology Mapping"; } /* features */ feature inventory-to-topology-navigate { description "Indicates support for navigating from inventory to topology."; } feature topology-to-inventory-navigate { description "Indicates support for navigating from topology to inventory."; } /* Groupings */ /* Node Grouping Feature with 1:1 mapping to NE*/ grouping node-inventory-feature-attributes { description "Network Inventory mapping node scope attributes"; container inventory-mapping-attributes { if-feature "topology-to-inventory-navigate"; config false; description "The container node attributes of Network Inventory mapping."; leaf ne-ref { type nwi:ne-ref; config false; description "1:1 mapping to the Network Element (NE) from which this node is abstracted."; } } } grouping tp-inventory-feature-attributes { description "Network Inventory mapping Termination Point (TP) scope attributes."; container inventory-mapping-attributes { if-feature "topology-to-inventory-navigate"; config false; description "Specifies the TP attributes of Network Inventory mapping."; /* 1:1 mapping to physical port component */ uses nwi:port-ref; // breakout channels (lightweight, per physical port) container port-breakout { presence "When present, it indicates that port breakout is supported."; description "Breakout capability of the physical port represented by this TP. One TP = one physical port; channels are listed here."; list breakout-channel { key "channel-id"; description "A single lane or sub-port that the physical port can be partitioned into."; leaf channel-id { type uint16; description "Unique index of the breakout channel within the port."; } } // breakout-channel } // port-breakout } } grouping link-inventory-feature-attributes { description "Network Inventory mapping link scope attributes."; container inventory-mapping-attributes { if-feature "topology-to-inventory-navigate"; config false; description "Specifies the link attributes of network inventory mapping."; leaf cable-name { type string; config false; description "Reports the reference of the cable inventory from which this link is abstracted."; } leaf link-type { type string; config false; description "Reports the type of the link."; } } } /* Main blocks */ augment "/nw:networks/nw:network/nw:node" { description "Groups parameters for inventory at the node level."; uses node-inventory-feature-attributes; } augment "/nw:networks/nw:network/nt:link" { description "Augments inventory topology link information."; uses link-inventory-feature-attributes; } augment "/nw:networks/nw:network/nw:node/nt:termination-point" { description "Augments inventory termination point information."; uses tp-inventory-feature-attributes; } /* Augment the network-inventory to add topology navigate */ augment "/nwi:network-inventory/nwi:network-elements" + "/nwi:network-element" { if-feature "inventory-to-topology-navigate"; description "Augments the network element with 1:1 mapping with the network the element is part of."; uses nw:node-ref; } } ]]>

Security Considerations This section is modeled after the template described in . The "ietf-network-inventory-topology" YANG module defines a data model that is designed to be accessed via YANG-based management protocols, such as NETCONF and RESTCONF . These YANG-based management (1) have to use a secure transport layer (e.g., SSH , TLS , and QUIC {{?RFC9000]) and (2) have to use mutual authentication. The Network Configuration Access Control Model (NACM) 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. No writable data nodes are defined in this module; all nodes are read-only ("config false"). 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 reference may be used to track the set of network elements.

IANA Considerations IANA is requested to register the following URI in the "ns" subregistry within the "IETF XML Registry" : IANA is requested to register the following YANG module in the "YANG Module Names" registry within the "YANG Parameters" registry group:

References Normative References Huawei Technologies Nokia Vodafone FiberCop Cisco This document defines a base YANG data model for reporting network inventory. The scope of this base model is set to be application- and technology-agnostic. The base data model can be augmented with application- and technology-specific details. This document defines an abstract (generic, or base) YANG data model for network/service topologies and inventories. The data model serves as a base model that is augmented with technology-specific details in other, more specific topology and inventory data models. This document defines a YANG data model for representing an abstract view of the provider network topology that contains the points from which its services can be attached (e.g., basic connectivity, VPN, network slices). Also, the model can be used to retrieve the points where the services are actually being delivered to customers (including peer networks). This document augments the 'ietf-network' data model defined in RFC 8345 by adding the concept of Service Attachment Points (SAPs). The SAPs are the network reference points to which network services, such as Layer 3 Virtual Private Network (L3VPN) or Layer 2 Virtual Private Network (L2VPN), can be attached. One or multiple services can be bound to the same SAP. Both User-to-Network Interface (UNI) and Network-to-Network Interface (NNI) are supported in the SAP data model. The standardization of network configuration interfaces for use with the Network Configuration Protocol (NETCONF) or the RESTCONF protocol requires a structured and secure operating environment that promotes human usability and multi-vendor interoperability. There is a need for standard mechanisms to restrict NETCONF or RESTCONF protocol access for particular users to a preconfigured subset of all available NETCONF or RESTCONF protocol operations and content. This document defines such an access control model. This document obsoletes RFC 6536. This document describes an IANA maintained registry for IETF standards which use Extensible Markup Language (XML) related items such as Namespaces, Document Type Declarations (DTDs), Schemas, and Resource Description Framework (RDF) Schemas. YANG is a data modeling language used to model configuration and state data manipulated by the Network Configuration Protocol (NETCONF), NETCONF remote procedure calls, and NETCONF notifications. [STANDARDS-TRACK] Informative References Huawei China Mobile Huawei Orange The base Network Inventory YANG model defines the physical network elements (NEs) and hardware components of NEs. This document extends the base Network Inventory model for non-physical NEs (e.g., controllers, virtual routers, virtual firewalls) and software components (e.g., platform operating system (OS), software-patch). This document defines a YANG data model for Layer 2 network topologies. In particular, this data model augments the generic network and network topology data models with topology attributes that are specific to Layer 2. This document defines a YANG data model for Layer 3 network topologies. This document captures the current syntax used in YANG module tree diagrams. The purpose of this document is to provide a single location for this definition. This syntax may be updated from time to time based on the evolution of the YANG language. China Mobile China Mobile China Mobile Huawei Orange Orange Digital Twin technology has been seen as a rapid adoption technology in Industry 4.0. The application of Digital Twin technology in the networking field is meant to develop various rich network applications, realize efficient and cost-effective data-driven network management, and accelerate network innovation. This document presents an overview of the concepts of Network Digital Twin, provides the basic definitions and a reference architecture, lists a set of application scenarios, and discusses such technology's benefits and key challenges. Huawei Everything OPS Telefonica Swisscom This document defines the concept of Service & Infrastructure Maps (SIMAP) and identifies a set of SIMAP requirements and use cases. The SIMAP was previously known as Digital Map. The document intends to be used as a reference for the assessment of the various topology modules to meet SIMAP requirements. YumaWorks Orange Huawei This document provides guidelines for authors and reviewers of specifications containing YANG data models, including IANA-maintained modules. Recommendations and procedures are defined, which are intended to increase interoperability and usability of Network Configuration Protocol (NETCONF) and RESTCONF Protocol implementations that utilize YANG modules. This document obsoletes RFC 8407. Also, this document updates RFC 8126 by providing additional guidelines for writing the IANA considerations for RFCs that specify IANA-maintained modules. The Network Configuration Protocol (NETCONF) defined in this document provides mechanisms to install, manipulate, and delete the configuration of network devices. It uses an Extensible Markup Language (XML)-based data encoding for the configuration data as well as the protocol messages. The NETCONF protocol operations are realized as remote procedure calls (RPCs). This document obsoletes RFC 4741. [STANDARDS-TRACK] This document describes an HTTP-based protocol that provides a programmatic interface for accessing data defined in YANG, using the datastore concepts defined in the Network Configuration Protocol (NETCONF). The Secure Shell Protocol (SSH) is a protocol for secure remote login and other secure network services over an insecure network. This document describes the SSH authentication protocol framework and public key, password, and host-based client authentication methods. Additional authentication methods are described in separate documents. The SSH authentication protocol runs on top of the SSH transport layer protocol and provides a single authenticated tunnel for the SSH connection protocol. [STANDARDS-TRACK] This document specifies version 1.3 of the Transport Layer Security (TLS) protocol. TLS allows client/server applications to communicate over the Internet in a way that is designed to prevent eavesdropping, tampering, and message forgery. This document updates RFCs 5705 and 6066, and obsoletes RFCs 5077, 5246, and 6961. This document also specifies new requirements for TLS 1.2 implementations. This document defines encoding rules for representing configuration data, state data, parameters of Remote Procedure Call (RPC) operations or actions, and notifications defined using YANG as JavaScript Object Notation (JSON) text.

Cable-Name / Link-Type Usage Examples This appendix illustrates when to populate the link-level cable-name and link-type leaves defined and when to rely on the forthcoming ietf-passive-inventory module for multi-segment passive paths.

• Direct Point-to-Point Cable

Topology: [TP-A] ——— 3 m duplex fibre ——— [TP-B] The link is realised by exactly one cable stock-keeping unit. cable-name is filled with the operator's asset tag; link-type is set to "fiber".

• Three-Segment Passive Path of Fiber Distribution Terminal (FDT)

Topology: [TP-A] —— FDT-1 —— segment —— FDT-2 —— [TP-B] The link spans two FDTs and one cable segment (no active inventory). cable-name is omitted; the controller derives the complete passive path by: 1. reading port-ref of TP-A and TP-B; 2. walking the passive-inventory relationships (FDT-1 ↔ cable ↔ FDT-2).

JSON Example of an 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 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", "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 Huawei

yuchaode@huawei.com