SPRING Working Group W. Cheng Internet-Draft W. Jiang Intended status: Standards Track China Mobile Expires: 10 September 2023 R. Chen D. Zhao ZTE Corporation C. Lin New H3C Technologies 9 March 2023 Network Resource Programming with SRv6 draft-cheng-spring-srv6-resource-programming-01 Abstract This document defines a new SRv6 network function which can be used for SRv6 Network Resource Programming. 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 10 September 2023. Copyright Notice Copyright (c) 2023 IETF Trust and the persons identified as the document authors. All rights reserved. Cheng, et al. Expires 10 September 2023 [Page 1] Internet-Draft SRv6 Network Resource Programming March 2023 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. End.NRP Behavior . . . . . . . . . . . . . . . . . . . . . . 3 4. Use Cases for End.NRP behavior . . . . . . . . . . . . . . . 4 5. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 6 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 6 7. Security Considerations . . . . . . . . . . . . . . . . . . . 6 8. Normative References . . . . . . . . . . . . . . . . . . . . 6 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 8 1. Introduction The concept of Network Resource Partition is introduced in [I-D.ietf-teas-ietf-network-slices]. A Network Resource Partition (NRP) is a set of network resources that are allocated from the underlay network to carry a specific set of network traffic and meet the required SLOs and SLEs. Segment Routing (SR) [RFC8402] leverages the source routing paradigm. An ingress node steers a packet through an ordered list of instructions, called "segments". Each one of these instructions represents a function to be called at a specific location in the network. A function is locally defined on the node where it is executed and may range from simply moving forward in the segment list to any complex user-defined behavior. SR Policy is an ordered list of segments (i.e., instructions) that represent a source-routed policy. The packets steered into an SR Policy have an ordered list of segments associated with that SR Policy. Since the SRv6 Endpoint behavior defined in [RFC8986] are not associated with a set of network resource partition of the interface for slices/slice aggregate(e.g.End.X just forwards to an endpoint with cross-connect to a 'layer-3 adjacency' or L2 bundles). Therefore, SRv6 policies can't achieve strict SLA guarantees. Cheng, et al. Expires 10 September 2023 [Page 2] Internet-Draft SRv6 Network Resource Programming March 2023 [I-D.ietf-spring-resource-aware-segments]extends the SR paradigm by associating SIDs with network resource attributes. On the basis of [I-D.ietf-spring-resource-aware-segments], this document defines a new SRv6 Endpoint behavior which can be used to associate with a set of network resource partition (e.g. bandwidth, buffer and queue resources ) Programming, called End.NRP. By using the End.NRP SID to build its segment list , the SRv6 policy has the capability to program network resources and achieve strict SLA guarantees. 2. 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 RFC 2119 [RFC2119]. 3. End.NRP Behavior This section defines a new SRv6 Endpoint behavior which can be used to associate with a set of snetwork resource partition (e.g. bandwidth, buffer and queue resources ) Programming, called End.NRP. The End.NRP is a variant of the End.X behavior defined in [RFC8986]. Any SID instance of End.NRP behavior is associated with two sets：J1 and J2. J1：one or more L3 adjacencies or L2 bundles J2：NRP of J1 When N receives a packet destined to S and S is a local End.NRP SID, the line S15 from the End processing defined in [RFC8986] is replaced by the following: S15. Submit the packet to the IPv6 module for transmission to the new destination via a member of J1, using the NRP identified by J2 This End.NRP SID can support the Penultimate Segment Pop (PSP) of the SRH, Ultimate Segment Pop (USP) of the SRH, and Ultimate Segment Decapsulation (USD) flavors defined in [RFC8986] either individually or in combinations. The SRH processing of the End.NRP behavior with PSP, USP, and USD is the same as [RFC8986]. This End.NRP SIDs can be allocated either by a centralized network controller or by the network nodes, and the End.NRP behavior can be announced using IGP or BGP-LS. The detailed protocol extension will be described in a separate document. Cheng, et al. Expires 10 September 2023 [Page 3] Internet-Draft SRv6 Network Resource Programming March 2023 4. Use Cases for End.NRP behavior This section describes possible procedures for the End.NRP behavior. A group of End.NRP SIDs can be allocated for the set of network resources associated with the SRv6 Policies, so that different End.NRP SIDs can be used to steer service traffic into different set of link resources (e.g. bandwidth, buffer and queue resources) in packet forwarding. Below is the possible procedures: 1. The controller get the topology information, calculate the SR Policy path based on SLA. 2. The controller cooperates with the network nodes to complete resource reservation and the End.NRP SID allocation along the SR Policy path. 3. The controller use the End.NRP SID to build the SID list for the explicit path. 4. Then the controller inform the headend the resource guaranteed path by various means including: via BGP [I-D.ietf-idr-segment-routing-te-policy], configuration or PCEP [RFC8664] [I-D.ietf-pce-segment-routing-policy-cp]. Cheng, et al. Expires 10 September 2023 [Page 4] Internet-Draft SRv6 Network Resource Programming March 2023 SRv6 Policy1 from PE1 to PE2 segment list SRv6 Policy2 from PE1 to PE2 segment list End.NRP12 End.NRP22 P1-----------P2 / | |\ / | | \ CE11------ End.NRP11 | |End.NRP13 ------ CE12 \ End.NRP21 | |End.NRP23 / \ / | | \ / PE1 \ | | PE2 / \ | | / \ / \ | | / \------ CE22 CE21------ \ | | / \ | | / P3------------P4 Figure 1 Figure 1 shows an example for the End.NRP behavior. As shown in Figure 1, there are two customers with different leased line requirements from PE1 to PE2: leased line1 : 1G BandWidth with strict SLA guarantee. leased line2 : 2G BandWidth with strict SLA guarantee. Below is the possible procedures: 1. The controller get the topology information, calculate the SRv6 Policy 1 and SRv6 Policy 2 based on SLA. 2. The controller cooperates with the network nodes to complete resource reservation and the End.NRP SID allocation along the SRv6 Policy1 and SRv6 Policy 2. Taking the interface PE1-P1 of SRv6 node PE1 along the SRv6 Policy 1 as an example, two different NRPs(e.g. two dedicated queues) are partitioned from the network resources of the physical link PE1-P1 (GE1/0/0). - The NRP(Queue1:1G BW)of link PE1- P1 is reserved and associated with End.NRP11 - The NRP(Queue2:2G BW)of link PE1- P1 is reserved and associated with End.NRP21. Cheng, et al. Expires 10 September 2023 [Page 5] Internet-Draft SRv6 Network Resource Programming March 2023 3. The controller uses the End.NRP11, End.NRP12, and End.NRP13 to build the SID list for the SRv6 Policy1 and use the End.NRP21, End.NRP22, and End.NRP23 to build the SID list for the SRv6 Policy 2. 4. Then the controller inform the headend the segment list of SRv6 Policy 1 and the segment list of SRv6 Policy 2 by various means including: via BGP [I-D.ietf-idr-segment-routing-te-policy], configuration or PCEP [RFC8664] [I-D.ietf-pce-segment-routing-policy-cp]. The traffic from customer1 and customer2 will be forwarded to PE2 through the NRPs previously reserved for each hop link on the path of SRv6 Policy1 and SRv6 Policy2 respectively, thus Customer 1 and Customer 2 are provided with end-to-end 1G bandwidth resources and 2G bandwidth resources respectively, and leased line services are guaranteed by strict SLAs. 5. Acknowledgements TBD. 6. IANA Considerations The document defines a new SRv6 Endpoint behavior called End.NRP. This I-D requests the IANA to allocate, within the "SRv6 Endpoint Behaviors" sub-registry belonging to the top-level "Segment-routing with IPv6 dataplane (SRv6) Parameters" registry, the following allocations: Value Endpoint Behavior Reference --------------------------------------------------------------- TBD1 End.NRP [This.ID] 7. Security Considerations TBD. 8. Normative References Cheng, et al. Expires 10 September 2023 [Page 6] Internet-Draft SRv6 Network Resource Programming March 2023 [I-D.ietf-idr-segment-routing-te-policy] Previdi, S., Filsfils, C., Talaulikar, K., Mattes, P., Jain, D., and S. Lin, "Advertising Segment Routing Policies in BGP", Work in Progress, Internet-Draft, draft- ietf-idr-segment-routing-te-policy-20, 27 July 2022, . [I-D.ietf-pce-segment-routing-policy-cp] Koldychev, M., Sivabalan, S., Barth, C., Peng, S., and H. Bidgoli, "PCEP extension to support Segment Routing Policy Candidate Paths", Work in Progress, Internet-Draft, draft- ietf-pce-segment-routing-policy-cp-08, 24 October 2022, . [I-D.ietf-spring-resource-aware-segments] Dong, J., Bryant, S., Miyasaka, T., Zhu, Y., Qin, F., Li, Z., and F. Clad, "Introducing Resource Awareness to SR Segments", Work in Progress, Internet-Draft, draft-ietf- spring-resource-aware-segments-06, 11 October 2022, . [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 IETF Network Slices", Work in Progress, Internet-Draft, draft-ietf-teas-ietf-network-slices-19, 21 January 2023, . [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, March 1997, . [RFC8402] Filsfils, C., Ed., Previdi, S., Ed., Ginsberg, L., Decraene, B., Litkowski, S., and R. Shakir, "Segment Routing Architecture", RFC 8402, DOI 10.17487/RFC8402, July 2018, . [RFC8664] Sivabalan, S., Filsfils, C., Tantsura, J., Henderickx, W., and J. Hardwick, "Path Computation Element Communication Protocol (PCEP) Extensions for Segment Routing", RFC 8664, DOI 10.17487/RFC8664, December 2019, . Cheng, et al. Expires 10 September 2023 [Page 7] Internet-Draft SRv6 Network Resource Programming March 2023 [RFC8986] Filsfils, C., Ed., Camarillo, P., Ed., Leddy, J., Voyer, D., Matsushima, S., and Z. Li, "Segment Routing over IPv6 (SRv6) Network Programming", RFC 8986, DOI 10.17487/RFC8986, February 2021, . Authors' Addresses Weiqiang Cheng China Mobile China Email: chengweiqiang@chinamobile.com Wenying Jiang China Mobile China Email: jiangwenying@chinamobile.com Ran Chen ZTE Corporation Nanjing China Email: chen.ran@zte.com.cn Detao Zhao ZTE Corporation Nanjing China Email: zhao.detao@zte.com.cn Changwang Lin New H3C Technologies China Email: linchangwang.04414@h3c.com Cheng, et al. Expires 10 September 2023 [Page 8]