Internet-Draft IS-IS PICS SR-MPLS YANG May 2024
Qu, et al. Expires 10 November 2024 [Page]
Intended Status:
Standards Track
Y. Qu
Futurewei Technologies
L. Ginsberg
Cisco Systems
A. Przygienda
Juniper Networks
Y. Zhu
China Telecom

YANG Model for IS-IS Segment Routing MPLS PICS


The YANG model in this document is to query an IS-IS Protocol Implementation Conformance Statement (PICS) of Segment Routing on MPLS data plane.

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

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 10 November 2024.

1. Overview

YANG [RFC7950] is a data definition language used to define the contents of a conceptual data store that allows networked devices to be managed using NETCONF [RFC6241]. YANG is proving relevant beyond its initial confines, as bindings to other interfaces (e.g., ReST) and encodings other than XML (e.g., JSON) are being defined. Furthermore, YANG data models can be used as the basis for implementation of other interfaces, such as CLI and programmatic APIs.

[I-D.qgp-lsr-isis-pics-yang] defines the framework to query IS-IS Protocol Implementation Conformance Statement (PICS). The module defined in this document is used to query an IS-IS PICS of Segment Routing on MPLS data plane [RFC8667].

The YANG modules in this document conform to the Network Management Datastore Architecture (NMDA) [RFC8342].

1.1. Requirements Language

The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in [RFC2119] [RFC8174].

2. Design of the Model

The YANG module is used to query an IS-IS implementation of Segment Routing on MPLS data plane [RFC8667] for the conformance of the protocol implementation.

Container "isis-pics-sr-mpls" only exists when "isis-pics-sr-mpls" is included in the list of "supported-isis-pics" in ietf-isis-pics module.

The existence of a TLV support container means the support of a TLV. The details of the flags and features are included in the container.


This document uses the graphical representation of data models defined in [RFC8340].

module: ietf-isis-pics-sr-mpls
  +--ro isis-pics-sr-mpls
     +--ro sr-capability-sub-tlv-support!
     |  +--ro i-bit-support?   isis-pics:support
     |  +--ro v-bit-support?   isis-pics:support
     +--ro prefix-sid-sub-tlv-support?         isis-pics:support
     +--ro adj-sid-sub-tlv-support?            isis-pics:support
     +--ro lan-adj-sid-sub-tlv-support?        isis-pics:support
     +--ro sid-label-tlv-support?              isis-pics:support
     +--ro sid-label-binding-tlv-support?      isis-pics:support
     +--ro mt-sid-label-binding-tlv-support?   isis-pics:support
     +--ro sr-algorithm-tlv-support!
     |  +--ro algo-support*   uint8
     +--ro sr-lb-tlv-support?                  isis-pics:support
     +--ro srms-preference-tlv-support?        isis-pics:support

  augment /isis-pics:isis-pics/isis-pics:isis-pics-mptlv:
    +--ro sid-label-binding-support?      isis-pics:support
    +--ro mt-sid-label-binding-support?   isis-pics:support


<CODE BEGINS> file "ietf-isis-pics-sr-mpls@2024-03-03.yang"
module ietf-isis-pics-sr-mpls {
  yang-version 1.1;
  namespace "urn:ietf:params:xml:ns:yang:ietf-isis-pics-sr-mpls";
  prefix isis-pics-sr-mpls;

  import iana-isis-pics {
    prefix "iana-isis-pics";

  import ietf-isis-pics {
    prefix "isis-pics";

    "IETF LSR - Link State Routing Working Group";
    "WG Web:   <>
     WG List:  <>

     Author:    Yingzhen Qu
     Author:   Les Ginsberg
     Author:   Tony Przygienda

    "The YANG module is used to query an IS-IS Protocol
     Implementation Conformance Statement (PICS) of Segment
     Routing for MPLS data plane (RFC8667).

     This YANG model conforms to the Network Management
     Datastore Architecture (NMDA) as described in RFC 8342.

     Copyright (c) 2024 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

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

     The key words 'MUST', 'MUST NOT', 'REQUIRED', 'SHALL', 'SHALL
     'MAY', and 'OPTIONAL' in this document are to be interpreted as
     described in BCP 14 (RFC 2119) (RFC 8174) when, and only when,
     they appear in all capitals, as shown here.";
    "RFC XXXX: YANG Data Model for IS-IS Segment Routing MPLS PICS";

  revision 2024-03-03 {
      "Initial Version";
      "RFC XXXX: YANG Data Model for IS-IS Segment Routing MPLS PICS.";

  container isis-pics-sr-mpls {
    when "/isis-pics:isis-pics/isis-pics:supported-isis-pics "
       + "= 'iana-isis-pics:isis-pics-sr-mpls'" {
        "This container only exists when isis-pics-sr-mpls is present
         in the ietf-isis-pics module.";
    config false;
      "IS-IS Protocol Implementation Conformance Statement (PICS) of
       Segment Routing on MPLS data plane.";
       "RFC 8667: IS-IS Extensions for Segment Routing";

    container sr-capability-sub-tlv-support {
      presence "Support of sr-capability sub-tlv.";
      //config false;
        "Support of sr-capability sub-tlv.";

      leaf i-bit-support {
        type isis-pics:support;
          "support mpls-ipv4 capability.";
      leaf v-bit-support {
        type isis-pics:support;
          "support mpls-ipv6 capability.";

    leaf prefix-sid-sub-tlv-support {
      type isis-pics:support;
        "Support of prefix-sid sub-tlv.";

    leaf adj-sid-sub-tlv-support {
      type isis-pics:support;
        "Support of Adjacency Segment Identifier sub-tlv.";

    leaf lan-adj-sid-sub-tlv-support {
      type isis-pics:support;
        "Support of LAN adj-sid sub-tlv.";

    leaf sid-label-tlv-support {
      type isis-pics:support;
        "Support of SID/Label sub-tlv.";

    leaf sid-label-binding-tlv-support {
      type isis-pics:support;
        "Support of SID/Label Binding tlv.";

    leaf mt-sid-label-binding-tlv-support {
      type isis-pics:support;
        "Support of Multi-Topology SID/Label Binding TLV.";

    container sr-algorithm-tlv-support {
      presence "Support of SR-Algorithm sub-tlv.";
        "Support of SR-Algorithm sub-tlv.";

      leaf-list algo-support {
        type uint8;
          "Supported algorithms.";

    leaf sr-lb-tlv-support {
      type isis-pics:support;
       "Support of the SR Local Block sub-tlv.";

    leaf srms-preference-tlv-support {
      type isis-pics:support;
       "Support of the SRMS Preference sub-tlv.";

  augment "/isis-pics:isis-pics/isis-pics:isis-pics-mptlv"
      "Augment isis-pics-mptlv container with the TLVs defined
       in RFC 8667.";

    leaf sid-label-binding-support {
      type isis-pics:support;
        "MP-TLV support of Segment Identifier/Label Binding TLV
        (type 149).";

    leaf mt-sid-label-binding-support {
      type isis-pics:support;
        "MP-TLV support of Multi-Topology Segment Identifier/Label
        Binding TLV(type 150).";

5. Security Considerations

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

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

Some of the readable data nodes in the ietf-isis-pics-sr-mpls.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.

6. IANA Considerations

The document requests IANA to create a entry, called isis-pics-sr-mpls in the "IS-IS PICS" registry [I-D.qgp-lsr-isis-pics-yang].

This document requests IANA to add a new "identity" to the iana-isis-pics YANG module. The following statement is suggested:

    identity isis-pics-sr-mpls {
     base "isis-pics";
        "The identity for support of SR MPLS.";
        "RFC 8667: IS-IS Extensions for Segment Routing.";

This document registers a URI in the IETF XML registry [RFC3688]. Following the format in [RFC3688], the following registration is requested to be made:

   URI: urn:ietf:params:xml:ns:yang:ietf-isis-pics-sr-mpls
   Registrant Contact: The IESG.
   XML: N/A, the requested URI is an XML namespace.

This document registers a YANG module in the YANG Module Names registry [RFC6020].

   name: ietf-isis-pics-sr-mpls
   namespace: urn:ietf:params:xml:ns:yang:ietf-isis-pics-sr-mpls
   prefix: isis-pics-sr-mpls
   reference: RFC XXXX

7. Acknowledgements

The YANG model was developed using the suite of YANG tools written and maintained by numerous authors.

8. Normative References

Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, , <>.
Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688, DOI 10.17487/RFC3688, , <>.
Bjorklund, M., Ed., "YANG - A Data Modeling Language for the Network Configuration Protocol (NETCONF)", RFC 6020, DOI 10.17487/RFC6020, , <>.
Enns, R., Ed., Bjorklund, M., Ed., Schoenwaelder, J., Ed., and A. Bierman, Ed., "Network Configuration Protocol (NETCONF)", RFC 6241, DOI 10.17487/RFC6241, , <>.
Wasserman, M., "Using the NETCONF Protocol over Secure Shell (SSH)", RFC 6242, DOI 10.17487/RFC6242, , <>.
Schoenwaelder, J., Ed., "Common YANG Data Types", RFC 6991, DOI 10.17487/RFC6991, , <>.
Bjorklund, M., Ed., "The YANG 1.1 Data Modeling Language", RFC 7950, DOI 10.17487/RFC7950, , <>.
Bierman, A., Bjorklund, M., and K. Watsen, "RESTCONF Protocol", RFC 8040, DOI 10.17487/RFC8040, , <>.
Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, , <>.
Bierman, A. and M. Bjorklund, "Network Configuration Access Control Model", STD 91, RFC 8341, DOI 10.17487/RFC8341, , <>.
Bjorklund, M., Schoenwaelder, J., Shafer, P., Watsen, K., and R. Wilton, "Network Management Datastore Architecture (NMDA)", RFC 8342, DOI 10.17487/RFC8342, , <>.
Rescorla, E., "The Transport Layer Security (TLS) Protocol Version 1.3", RFC 8446, DOI 10.17487/RFC8446, , <>.
Previdi, S., Ed., Ginsberg, L., Ed., Filsfils, C., Bashandy, A., Gredler, H., and B. Decraene, "IS-IS Extensions for Segment Routing", RFC 8667, DOI 10.17487/RFC8667, , <>.
ISO, "Intermediate system to Intermediate system routing information exchange protocol for use in conjunction with the Protocol for providing the Connectionless-mode Network Service (ISO 8473)", , <ISO/IEC 10589:2002>.
Qu, Y., Ginsberg, L., and T. Przygienda, "YANG Model for IS-IS Protocol Implementation Conformance Statement (PICS)", Work in Progress, Internet-Draft, draft-qgp-lsr-isis-pics-yang-00, , <>.

9. Informative References

Bjorklund, M. and L. Berger, Ed., "YANG Tree Diagrams", BCP 215, RFC 8340, DOI 10.17487/RFC8340, , <>.

Authors' Addresses

Yingzhen Qu
Futurewei Technologies
Les Ginsberg
Cisco Systems
Antoni Przygienda
Juniper Networks
Yongqing Zhu
China Telecom