Internet-Draft Advertise Node Ix January 2024
Chen, et al. Expires 13 July 2024 [Page]
Workgroup:
Network Working Group
Internet-Draft:
draft-chen-lsr-adv-ni-03
Published:
Intended Status:
Standards Track
Expires:
Authors:
H. Chen
Futurewei
D. Eastlake
Futurewei
A. Wang
China Telecom
G. Mishra
Verizon Inc.
Y. Liu
China Mobile
Y. Fan
Casa Systems
L. Liu
Fujitsu
X. Liu
Alef Edge

IGP Extensions for Advertising Node Index

Abstract

This document describes OSPF and IS-IS extensions for distributing the node index configured on a node.

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] when, and only when, they appear in all capitals, as shown here.

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 13 July 2024.

1. Introduction

When the nodes in a network are numbered or indexed from 1 to the number of the nodes, an efficient stateless multicast along the shortest paths to the egresses of a P2MP tree can be achieved using the node indices of the egresses.

This document proposes OSPF and IS-IS extensions for distributing the node index configured on a node to support the best effort stateless multicast. When a controller such as PCE as a controller has the node indexes, it can send the P2MP tree encoded in the node indexes to the ingress of the tree.

1.1. Terminology

LSA:
Link State Advertisement.
OSPF:
Open Shortest Path First.
LSP:
Link State Protocol data unit.
IS-IS:
Intermediate System to Intermediate System.

2. Extensions to OSPF

This section describes extensions to OSPF for distributing the node index configured on a node. The node index of a node MUST be unique in a network. This is like the identifier (ID) of the node.

[RFC7770] defines the Router Information (RI) Link state Advertisement (LSA). The RI LSA is used to advertise Optional Router Information using Router Information LSA TLVs. A new Router Information LSA TLV, called Node Index TLV, is defined to carry the Node Index configured on the node originating the RI LSA. The Node Index TLV has the following format:

    0                   1                   2                   3
    0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |          Type (TBD1)          |           Length (2)          |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |            Node Index         |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 1: Node Index TLV
Type:
TBD1.
Length:
2.
Node Index:
The node index configured on a node.

This TLV is optional. It is applicable to both OSPFv2 and OSPFv3. For advertising a node index, the area-scoped RI LSA including a Node Index TLV is used.

3. Extension to IS-IS

This section describes an extension to IS-IS for distributing the Node Index configured on a node.

[RFC7981] defines the IS-IS Router CAPABILITY TLV to advertise Router Information. The TLV includes multiple sub-TLVs. A new Node Index sub-TLV to be included in the TLV, is defined to carry the Node Index configured on the node originating the TLV in its LSP. This sub-TLV has the following format:

  0                   1                   2                   3
  0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |  Type (TBD2)  |   Length (2)  |           Node Index          |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 2: Node Index sub-TLV
Type:
TBD2.
Length:
2.
Node Index:
The Node Index configured on a node.

This sub-TLV is optional. For advertising a node index, the area-scoped LSP including a Node Index sub-TLV in an IS-IS Router CAPABILITY TLV is used.

5. IANA Considerations

5.1. OSPF RI TLVs Registry

Under "OSPF Router Information (RI) TLVs registry" as defined in [RFC7770], IANA is requested to assign a new type as follows:

  +==============+===================+=====================+
  |  Value       |  Description      |    reference        |
  +==============+===================+=====================+
  |  TBD1        |  Node Index       |    This document    |
  +--------------+-------------------+---------------------+

5.2. IS-IS Sub-TLVs for TLV 242 Registry

Under "Sub-TLVs for TLV 242 (IS-IS Router CAPABILITY TLV) registry" as defined in [RFC7981], IANA is requested to assign a new sub-TLV as follows:

  +==============+===================+=====================+
  |  Value       |  Description      |    reference        |
  +==============+===================+=====================+
  |  TBD2        |  Node Index       |    This document    |
  +--------------+-------------------+---------------------+

6. Acknowledgements

The authors would like to thank people for their comments on this work.

7. References

7.1. Normative References

[RFC2119]
Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, , <https://www.rfc-editor.org/info/rfc2119>.
[RFC5226]
Narten, T. and H. Alvestrand, "Guidelines for Writing an IANA Considerations Section in RFCs", RFC 5226, DOI 10.17487/RFC5226, , <https://www.rfc-editor.org/info/rfc5226>.
[RFC7770]
Lindem, A., Ed., Shen, N., Vasseur, JP., Aggarwal, R., and S. Shaffer, "Extensions to OSPF for Advertising Optional Router Capabilities", RFC 7770, DOI 10.17487/RFC7770, , <https://www.rfc-editor.org/info/rfc7770>.
[RFC7981]
Ginsberg, L., Previdi, S., and M. Chen, "IS-IS Extensions for Advertising Router Information", RFC 7981, DOI 10.17487/RFC7981, , <https://www.rfc-editor.org/info/rfc7981>.
[RFC8174]
Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, , <https://www.rfc-editor.org/info/rfc8174>.

7.2. Informative References

[RFC5250]
Berger, L., Bryskin, I., Zinin, A., and R. Coltun, "The OSPF Opaque LSA Option", RFC 5250, DOI 10.17487/RFC5250, , <https://www.rfc-editor.org/info/rfc5250>.

Authors' Addresses

Huaimo Chen
Futurewei
Boston, MA,
United States of America
Donald E. Eastlake 3rd
Futurewei
2386 Panoramic Circle
Apopka, FL, 32703
United States of America
Aijun Wang
China Telecom
Beiqijia Town, Changping District
Beijing
102209
China
Gyan S. Mishra
Verizon Inc.
13101 Columbia Pike
Silver Spring, MD 20904
United States of America
Phone: 301 502-1347
Yisong Liu
China Mobile
Yanhe Fan
Casa Systems
United States of America
Lei Liu
Fujitsu
United States of America
Xufeng Liu
Alef Edge
United States of America