IDR R. Chen Internet-Draft ZTE Corporation Intended status: Standards Track J. Dong Expires: 19 September 2024 Huawei D. Zhao ZTE Corporation L. Gong China mobile Y. Zhu China Telecom R. Pang China Unicom 18 March 2024 SR Policies Extensions for NRP in BGP-LS draft-chen-idr-bgp-ls-sr-policy-nrp-06 Abstract This document defines a new TLV which enable the headend to report the configuration and the states of SR policies carrying NRP information by using BGP-LS. 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 19 September 2024. Copyright Notice Copyright (c) 2024 IETF Trust and the persons identified as the document authors. All rights reserved. Chen, et al. Expires 19 September 2024 [Page 1] Internet-Draft SR policy NRP in BGP-LS March 2024 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 Revised BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Revised BSD License. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 2. Requirements Language . . . . . . . . . . . . . . . . . . . . 3 3. Carrying NRP TLV in BGP-LS . . . . . . . . . . . . . . . . . 3 4. Scalability Considerations . . . . . . . . . . . . . . . . . 4 5. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 4 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 4 7. Security Considerations . . . . . . . . . . . . . . . . . . . 4 8. Informative References . . . . . . . . . . . . . . . . . . . 5 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 6 1. Introduction Segment Routing Policy [RFC9256] is an ordered list of segments (i.e. instructions) that represent a source-routed policy. Packet flows are steered into a SR Policy on a node where it is instantiated called a headend node. The packets steered into an SR Policy carry an ordered list of segments associated with that SR Policy. [I-D.ietf-teas-ietf-network-slices] provides the definition of IETF network slice for use within the IETF and discusses the general framework for requesting and operating IETF Network Slices, their characteristics, and the necessary system components and interfaces.It also introduces the concept Network Resource Partition (NRP), which is a subset of the resources and associated policies in the underlay network. [I-D.ietf-teas-ns-ip-mpls] introduces the notion of a Slice-Flow Aggregate which comprises of one or more IETF network slice traffic streams. It also describes the Network Resource Partition (NRP) and the NRP Policy that can be used to instantiate control and data plane behaviors on select topological elements associated with the NRP that supports a Slice-Flow Aggregate. [I-D.ietf-idr-bgp-ls-sr-policy] describes a mechanism to distribute SR policy information to external components using BGP-LS. Chen, et al. Expires 19 September 2024 [Page 2] Internet-Draft SR policy NRP in BGP-LS March 2024 [I-D.ietf-idr-sr-policy-nrp] defines the extensions to BGP SR policy to specify the NRP which the SR Policy candidate path is associated with. This document defines a new TLV which enable the headend to report the configuration and the states of an SR policy carrying the NRP information by using BPG-LS. 2. Requirements Language The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all capitals, as shown here. 3. Carrying NRP TLV in BGP-LS In order to collect configuration and states of the NRP SR policy, this document defines a new SR Policy state TLV which enable the headend to report the state at the SR Policy CP level. This TLV is carried in the optional non-transitive BGP Attribute "LINK_STATE Attribute" defined in [RFC9552]associated with the SR Policy CP NLRI type. This TLV is optional and only one this TLV is advertised for a given CP. If multiple TLVs are present, then the first one is considered valid and the rest are ignored as describe in [I-D.ietf-idr-bgp-ls-sr-policy]. The 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 | Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Flag | Reserved | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | NRP ID (4 octets) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ where: Type: TBD. Chen, et al. Expires 19 September 2024 [Page 3] Internet-Draft SR policy NRP in BGP-LS March 2024 Length: The total length of the value field not including Type and Length fields. Flag: 2-octet flag field. None is defined at this stage. The flags SHOULD be set to zero on transmission and MUST be ignored on receipt. RESERVED: 2-octet reserved bits. It SHOULD be set to zero on transmission and MUST be ignored on receipt. NRP ID: 4-octet domain significant identifier of Network Resource Partition. Value 0 and 0xFFFFFFFF are reserved. 4. Scalability Considerations The mechanism specified in this document defines the headend to report configuration and states of an SR policy carrying the NRP information by using BPG-LS. BGP-LS SR Policy is used to report the SR Policy attributes and status. As the number of NRP increases, the number of SR Policies would also increase accordingly, and the status reported by the headend increases accordingly. However, this will only cause an increase in the status reporting information of the head node, the impacts to the BGP control plane are considered acceptable. 5. Acknowledgements The authors would like to thank Changwang Lin for their review and discussion of this document. 6. IANA Considerations IANA maintains a registry group called "Border Gateway Protocol - Link State (BGP-LS) Parameters" with a registry called "BGP-LS NLRI and Attribute TLVs". The following TLV codepoints are suggested (for early allocation by IANA): Codepoint Description Reference ---------------------------------------------------------- TBD NRP This document 7. Security Considerations Procedures and protocol extensions defined in this document do not affect the BGP security model. See the "Security Considerations"section of [RFC4271] for a discussion of BGP security.Security considerations for acquiring and distributing BGP- LS information are discussed in [RFC9552]. Chen, et al. Expires 19 September 2024 [Page 4] Internet-Draft SR policy NRP in BGP-LS March 2024 8. Informative References [I-D.ietf-idr-bgp-ls-sr-policy] Previdi, S., Talaulikar, K., Dong, J., Gredler, H., and J. Tantsura, "Advertisement of Segment Routing Policies using BGP Link-State", Work in Progress, Internet-Draft, draft- ietf-idr-bgp-ls-sr-policy-03, 5 November 2023, . [I-D.ietf-idr-sr-policy-nrp] Dong, J., Hu, Z., and R. Pang, "BGP SR Policy Extensions for Network Resource Partition", Work in Progress, Internet-Draft, draft-ietf-idr-sr-policy-nrp-00, 17 December 2023, . [I-D.ietf-teas-ietf-network-slices] Farrel, A., Drake, J., Rokui, R., Homma, S., Makhijani, K., Contreras, L. M., and J. Tantsura, "A Framework for Network Slices in Networks Built from IETF Technologies", Work in Progress, Internet-Draft, draft-ietf-teas-ietf- network-slices-25, 14 September 2023, . [I-D.ietf-teas-ns-ip-mpls] Saad, T., Beeram, V. P., Dong, J., Wen, B., Ceccarelli, D., Halpern, J. M., Peng, S., Chen, R., Liu, X., Contreras, L. M., Rokui, R., and L. Jalil, "Realizing Network Slices in IP/MPLS Networks", Work in Progress, Internet-Draft, draft-ietf-teas-ns-ip-mpls-03, 26 November 2023, . [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, March 1997, . [RFC4271] Rekhter, Y., Ed., Li, T., Ed., and S. Hares, Ed., "A Border Gateway Protocol 4 (BGP-4)", RFC 4271, DOI 10.17487/RFC4271, January 2006, . [RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, May 2017, . Chen, et al. Expires 19 September 2024 [Page 5] Internet-Draft SR policy NRP in BGP-LS March 2024 [RFC9256] Filsfils, C., Talaulikar, K., Ed., Voyer, D., Bogdanov, A., and P. Mattes, "Segment Routing Policy Architecture", RFC 9256, DOI 10.17487/RFC9256, July 2022, . [RFC9552] Talaulikar, K., Ed., "Distribution of Link-State and Traffic Engineering Information Using BGP", RFC 9552, DOI 10.17487/RFC9552, December 2023, . Authors' Addresses Ran Chen ZTE Corporation Nanjing China Email: chen.ran@zte.com.cn Jie Dong Huawei Beijing China Email: jie.dong@huawei.com Detao Zhao ZTE Corporation Nanjing China Email: zhao.detao@zte.com.cn Liyan Gong China mobile Beijing China Email: gongliyan@chinamobile.com Yongqing Zhu China Telecom Guangzhou China Email: zhuyq8@chinatelecom.cn Chen, et al. Expires 19 September 2024 [Page 6] Internet-Draft SR policy NRP in BGP-LS March 2024 Ran Pang China Unicom Beijing China Email: pangran@chinaunicom.cn Chen, et al. Expires 19 September 2024 [Page 7]