Network Working Group H. Chen Internet-Draft M. McBride Intended status: Standards Track Futurewei Expires: October 16, 2021 A. Wang China Telecom G. Mishra Verizon Inc. Y. Fan Casa Systems L. Liu Fujitsu X. Liu Volta Networks April 14, 2021 IS-IS Extensions for BIER-TE draft-chen-bier-te-isis-00 Abstract This document describes IS-IS extensions for distributing BitPositions configured on the links in "Bit Index Explicit Replication Traffic Engineering" (BIER-TE) domain. 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 October 16, 2021. Chen, et al. Expires October 16, 2021 [Page 1] Internet-Draft ISIS for BIER-TE April 2021 Copyright Notice Copyright (c) 2021 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 Simplified BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 1.1. Terminology . . . . . . . . . . . . . . . . . . . . . . . 3 2. Extensions to IS-IS . . . . . . . . . . . . . . . . . . . . . 3 3. Security Considerations . . . . . . . . . . . . . . . . . . . 5 4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 5 5. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 5 6. References . . . . . . . . . . . . . . . . . . . . . . . . . 5 6.1. Normative References . . . . . . . . . . . . . . . . . . 5 6.2. Informative References . . . . . . . . . . . . . . . . . 6 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 6 1. Introduction [I-D.ietf-bier-te-arch] introduces Bit Index Explicit Replication (BIER) Traffic/Tree Engineering (BIER-TE). It is an architecture for per-packet stateless explicit point to multipoint (P2MP) multicast path/tree. A link in a BIER-TE domain has its BitPositions. For a link between two nodes X and Y, there are two BitPositions for two forward connected adjacencies. These two adjacency BitPositions could be configured on nodes X and Y respectively. The BitPosition configured on X is the forward connected adjacency of Y. The BitPosition configured on Y is the forward connected adjacency of X. This document proposes IS-IS extensions for distributing BitPositions configured on the links in "Bit Index Explicit Replication Traffic Engineering" (BIER-TE) domain. Chen, et al. Expires October 16, 2021 [Page 2] Internet-Draft ISIS for BIER-TE April 2021 1.1. Terminology BIER: Bit Index Explicit Replication. BIER-TE: BIER Traffic Engineering. BFR: Bit-Forwarding Router. BFIR: Bit-Forwarding Ingress Router. BFER: Bit-Forwarding Egress Router. BFR-id: BFR Identifier. It is a number in the range [1,65535]. BFR-NBR: BFR Neighbor. IS-IS: Intermediate System to Intermediate System. 2. Extensions to IS-IS This section describes protocol extensions to IS-IS for distributing BIER-TE information such as the BitPositions configured on the links in a BIER-TE domain. An Extended IS Reachability TLV (Type 22) defined in [RFC5305] may contain Sub-TLVs (such as those for TE) that apply to a link/ interface to a neighbor. To encode multiple links or interfaces to neighbors, the structure inside TLV is repeated. MT Intermediate Systems TLV (Type 222) defined in [RFC5120] may contain Sub-TLVs (such as those for TE) that apply to a link/ interface. It is aligned with Extended IS Reachability TLV (Type 22) beside an additional two bytes in front at the beginning of the TLV for MT-ID. BIER-TE Info Sub-TLV of the following format is defined and used in Extended IS Reachability TLV (Type 22) and/or MT Intermediate Systems TLV (Type 222) to advertise the BIER-TE information about a link or interface. Chen, et al. Expires October 16, 2021 [Page 3] Internet-Draft ISIS for BIER-TE April 2021 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 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | sub-domain-id | BAR | IPA | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | BitPosition | DisEndBitPosition | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Sub-Sub-TLVs (variable) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 1: BIER-TE Info Sub-TLV Type: TBD1 is to be assigned by IANA. Length: Variable, dependent on Sub-Sub-TLVs. sub-domain-id: Unique value identifying a BIER-TE sub-domain. BAR: Single-octet BIER Algorithm used to calculate underlay paths to reach other BFRs. Values are allocated from the "BIER Algorithm" registry defined in [RFC8401]. IPA: Single-octet IGP Algorithm used to either modify, enhance, or replace the calculation of underlay paths to reach other BFRs as defined by the BAR value. Values are defined in the "IGP Algorithm Types" registry. BitPosition: A 2-octet field encoding the BitPosition locally configured on the link/interface to an Intermediate System neighbor. DisEndBitPosition: A 2-octet field encoding the BitPosition of the connection on the designated Intermediate Systems (Dis) end. This field is valid when the neighbor is a pseudonode. If the neighbor is not a pseudonode, this field MUST be ignored. The DisEndBitPosition may be configured on the link/interface to a transit network (i.e., broadcast link or say LAN). No Sub-Sub-TLV is defined so far. Note that if each of BitPosition and DrEndBitPosition uses more than 2 octets, we use 4 or more octets for each of them. Chen, et al. Expires October 16, 2021 [Page 4] Internet-Draft ISIS for BIER-TE April 2021 3. Security Considerations TBD. 4. IANA Considerations Under "Sub-TLVs for TLVs 22, 23, 25, 141, 222, and 223" for IS-IS TLV Codepoints, IANA is requested to assign a new codepoint for BIER-TE Info Sub-TLV as follows: +============+=============+==+==+==+===+===+===+=============+ |Sub-TLV Type|Sub-TLV Name |22|23|25|141|222|223|reference | +============+=============+==+==+==+===+===+===+=============+ | TBD1 |BIER-TE Info |y |n |n | n | y | n |This document| +------------+-------------+--+--+--+---+---+---+-------------+ 5. Acknowledgements The authors would like to thank people for their comments to this work. 6. References 6.1. Normative References [I-D.ietf-bier-te-arch] Eckert, T., Cauchie, G., and M. Menth, "Tree Engineering for Bit Index Explicit Replication (BIER-TE)", draft-ietf- bier-te-arch-09 (work in progress), October 2020. [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, March 1997, . [RFC5120] Przygienda, T., Shen, N., and N. Sheth, "M-ISIS: Multi Topology (MT) Routing in Intermediate System to Intermediate Systems (IS-ISs)", RFC 5120, DOI 10.17487/RFC5120, February 2008, . [RFC5226] Narten, T. and H. Alvestrand, "Guidelines for Writing an IANA Considerations Section in RFCs", RFC 5226, DOI 10.17487/RFC5226, May 2008, . Chen, et al. Expires October 16, 2021 [Page 5] Internet-Draft ISIS for BIER-TE April 2021 [RFC5305] Li, T. and H. Smit, "IS-IS Extensions for Traffic Engineering", RFC 5305, DOI 10.17487/RFC5305, October 2008, . [RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, May 2017, . [RFC8279] Wijnands, IJ., Ed., Rosen, E., Ed., Dolganow, A., Przygienda, T., and S. Aldrin, "Multicast Using Bit Index Explicit Replication (BIER)", RFC 8279, DOI 10.17487/RFC8279, November 2017, . 6.2. Informative References [RFC8296] Wijnands, IJ., Ed., Rosen, E., Ed., Dolganow, A., Tantsura, J., Aldrin, S., and I. Meilik, "Encapsulation for Bit Index Explicit Replication (BIER) in MPLS and Non- MPLS Networks", RFC 8296, DOI 10.17487/RFC8296, January 2018, . [RFC8401] Ginsberg, L., Ed., Przygienda, T., Aldrin, S., and Z. Zhang, "Bit Index Explicit Replication (BIER) Support via IS-IS", RFC 8401, DOI 10.17487/RFC8401, June 2018, . [RFC8556] Rosen, E., Ed., Sivakumar, M., Przygienda, T., Aldrin, S., and A. Dolganow, "Multicast VPN Using Bit Index Explicit Replication (BIER)", RFC 8556, DOI 10.17487/RFC8556, April 2019, . Authors' Addresses Huaimo Chen Futurewei Boston, MA USA Email: Huaimo.chen@futurewei.com Mike McBride Futurewei Email: michael.mcbride@futurewei.com Chen, et al. Expires October 16, 2021 [Page 6] Internet-Draft ISIS for BIER-TE April 2021 Aijun Wang China Telecom Beiqijia Town, Changping District Beijing, 102209 China Email: wangaj3@chinatelecom.cn Gyan S. Mishra Verizon Inc. 13101 Columbia Pike Silver Spring MD 20904 USA Phone: 301 502-1347 Email: gyan.s.mishra@verizon.com Yanhe Fan Casa Systems USA Email: yfan@casa-systems.com Lei Liu Fujitsu USA Email: liulei.kddi@gmail.com Xufeng Liu Volta Networks McLean, VA USA Email: xufeng.liu.ietf@gmail.com Chen, et al. Expires October 16, 2021 [Page 7]