idnits 2.17.1 draft-bestbar-lsr-spring-sa-00.txt: Checking boilerplate required by RFC 5378 and the IETF Trust (see https://trustee.ietf.org/license-info): ---------------------------------------------------------------------------- No issues found here. Checking nits according to https://www.ietf.org/id-info/1id-guidelines.txt: ---------------------------------------------------------------------------- No issues found here. Checking nits according to https://www.ietf.org/id-info/checklist : ---------------------------------------------------------------------------- No issues found here. Miscellaneous warnings: ---------------------------------------------------------------------------- == The copyright year in the IETF Trust and authors Copyright Line does not match the current year -- The document date (February 22, 2021) is 1152 days in the past. Is this intentional? Checking references for intended status: Proposed Standard ---------------------------------------------------------------------------- (See RFCs 3967 and 4897 for information about using normative references to lower-maturity documents in RFCs) == Outdated reference: A later version (-02) exists of draft-bestbar-spring-scalable-ns-00 == Outdated reference: A later version (-10) exists of draft-bestbar-teas-ns-packet-01 ** Downref: Normative reference to an Informational draft: draft-bestbar-teas-ns-packet (ref. 'I-D.bestbar-teas-ns-packet') == Outdated reference: A later version (-19) exists of draft-ietf-lsr-isis-srv6-extensions-11 ** Obsolete normative reference: RFC 5316 (Obsoleted by RFC 9346) == Outdated reference: A later version (-01) exists of draft-ietf-teas-ietf-network-slice-definition-00 == Outdated reference: A later version (-05) exists of draft-nsdt-teas-ns-framework-04 Summary: 2 errors (**), 0 flaws (~~), 6 warnings (==), 1 comment (--). Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 2 LSR Working Group T. Saad 3 Internet-Draft V. Beeram 4 Intended status: Standards Track Juniper Networks 5 Expires: August 26, 2021 R. Chen 6 S. Peng 7 ZTE Corporation 8 B. Wen 9 Comcast 10 D. Ceccarelli 11 Ericsson 12 February 22, 2021 14 IGP Extensions for SR Slice Aggregate SIDs 15 draft-bestbar-lsr-spring-sa-00 17 Abstract 19 Segment Routing (SR) defines a set of topological "segments" within 20 an IGP topology to enable steering over a specific SR path. These 21 segments are advertised by the link-state routing protocols (IS-IS 22 and OSPF). 24 This document describes extensions to the IS-IS that enable 25 advertising Slice Aggregate SR segments that share the same IGP 26 computed forwarding path but offer a forwarding treatment (e.g. 27 scheduling and drop policy) that is associated with a specific Slice 28 Aggregate. 30 Status of This Memo 32 This Internet-Draft is submitted in full conformance with the 33 provisions of BCP 78 and BCP 79. 35 Internet-Drafts are working documents of the Internet Engineering 36 Task Force (IETF). Note that other groups may also distribute 37 working documents as Internet-Drafts. The list of current Internet- 38 Drafts is at https://datatracker.ietf.org/drafts/current/. 40 Internet-Drafts are draft documents valid for a maximum of six months 41 and may be updated, replaced, or obsoleted by other documents at any 42 time. It is inappropriate to use Internet-Drafts as reference 43 material or to cite them other than as "work in progress." 45 This Internet-Draft will expire on August 26, 2021. 47 Copyright Notice 49 Copyright (c) 2021 IETF Trust and the persons identified as the 50 document authors. All rights reserved. 52 This document is subject to BCP 78 and the IETF Trust's Legal 53 Provisions Relating to IETF Documents 54 (https://trustee.ietf.org/license-info) in effect on the date of 55 publication of this document. Please review these documents 56 carefully, as they describe your rights and restrictions with respect 57 to this document. Code Components extracted from this document must 58 include Simplified BSD License text as described in Section 4.e of 59 the Trust Legal Provisions and are provided without warranty as 60 described in the Simplified BSD License. 62 Table of Contents 64 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 65 2. Requirements Language . . . . . . . . . . . . . . . . . . . . 3 66 3. Slice Aggregate SIDs for SR-MPLS . . . . . . . . . . . . . . 3 67 3.1. IS-IS Slice Aggregate Prefix-SID Sub-TLV . . . . . . . . 3 68 3.2. IS-IS Slice Aggregate Adjacency-SID Sub-TLV . . . . . . . 5 69 3.3. IS-IS Slice Aggregate LAN Adjacency-SIDs . . . . . . . . 6 70 4. Slice Aggregate SIDs for SRv6 . . . . . . . . . . . . . . . . 7 71 4.1. SRv6 SID Slice Aggregate Sub-Sub-TLV . . . . . . . . . . 7 72 5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 8 73 5.1. SR Slice Aggregate Prefix-SID sub-TLV . . . . . . . . . . 9 74 5.2. SR Slice Aggregate Adjacency-SID sub-TLV . . . . . . . . 9 75 5.3. SR Slice Aggregate LAN-Adj-SID sub-TLV . . . . . . . . . 9 76 5.4. SRv6 SID Slice Aggregate Sub-Sub-TLV . . . . . . . . . . 9 77 6. Security Considerations . . . . . . . . . . . . . . . . . . . 9 78 7. Acknowledgement . . . . . . . . . . . . . . . . . . . . . . . 9 79 8. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 9 80 9. References . . . . . . . . . . . . . . . . . . . . . . . . . 10 81 9.1. Normative References . . . . . . . . . . . . . . . . . . 10 82 9.2. Informative References . . . . . . . . . . . . . . . . . 11 83 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 12 85 1. Introduction 87 The Segment Routing (SR) architecture [RFC8402] defines a set of 88 topological "segments" within an IGP topology as means to enable 89 steering over a specific SR end-to-end path. These segments are 90 advertised by the IGP link-state routing protocols (IS-IS and OSPF). 91 The SR control plane can be applied to both IPv6 and MPLS data 92 planes. 94 The definition of a network slice for use within the IETF and the 95 characteristics of IETF network slice are specified in 96 [I-D.ietf-teas-ietf-network-slice-definition]. A framework for 97 reusing IETF VPN and traffic-engineering technologies to realize IETF 98 network slices is discussed in [I-D.nsdt-teas-ns-framework]. 100 [I-D.bestbar-teas-ns-packet] introduces the notion of a Slice 101 Aggregate as the construct that comprises of one of more IETF network 102 slice traffic streams. A slice policy can be used to realize a slice 103 aggregate by instantiating specific control and data plane resources 104 on select topological elements in an IP/MPLS network. 106 [I-D.bestbar-spring-scalable-ns] describes an approach to extend SR 107 to advertiser new SID types called Slice Aggregate (SA) SIDs. Such 108 SA SIDs are used on a router to define the forwarding action for a 109 packet (next-hop selection), as well as enforce the specific 110 treatment (scheduling and drop policy) associated with the Slice 111 Aggregate. 113 This document defines the IS-IS and OSPF encodings for the IGP-Prefix 114 Segment, the IGP-Adjacency Segment, the IGP-LAN-Adjacency Segment 115 that are required to support the signaling of SR Slice Aggregate SIDs 116 operating over SR-MPLS and SRv6 dataplanes. When the Slice Aggregate 117 segments have the same topology (and Algorithm for Prefix-SIDs), the 118 SA SIDs share the same forwarding path (IGP next-hop(s)), but are 119 associated with different forwarding treatment (e.g. scheduling and 120 drop policy) that is associated with the specific Slice Aggregate. 122 2. Requirements Language 124 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 125 "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and 126 "OPTIONAL" in this document are to be interpreted as described in BCP 127 14 [RFC2119] [RFC8174] when, and only when, they appear in all 128 capitals, as shown here. 130 3. Slice Aggregate SIDs for SR-MPLS 132 Segment Routing can be directly instantiated on the MPLS data plane 133 through the use of the Segment Routing header instantiated as a stack 134 of MPLS labels defined in [RFC8402]. 136 3.1. IS-IS Slice Aggregate Prefix-SID Sub-TLV 138 [RFC8667] defines the IS-IS Prefix Segment Identifier sub-TLV 139 (Prefix-SID sub-TLV) that is applicable to SR-MPLS dataplane. The 140 Prefix-SID sub-TLV carries the Segment Routing IGP-Prefix-SID, and is 141 associated with a prefix advertised by a router. 143 A new IS-IS SR Slice Aggregate Prefix-SID (SA Prefix-SID) sub-TLV is 144 defined to allow a router advertising a prefix to associate multiple 145 SA Prefix-SIDs to the same prefix. The SA Prefix-SIDs associated 146 with the same prefix share the same IGP path to the destination 147 prefix within the specific mapped or customized topology/algorithm 148 but offer the specific QoS treatment associated with the specific 149 Slice Aggregate. 151 The Slice Aggregate ID is carried in the SA Prefix-SID sub-TLV to 152 associate it to Prefix-SID with a specific Slice Aggregate. The SA 153 Prefix-SID sub-TLV has the following format: 155 0 1 2 3 156 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 1 157 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 158 | Type=TBD1 | Length | Flag | Algorithm | 159 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 160 | SA-ID | 161 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 162 | SID/Index/Label(Variable) | 163 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 165 Figure 1: SA Prefix-SID sub-TLV for SR-MPLS. 167 where: 169 Type: TBD1 (Suggested value to be assigned by IANA) 171 Length: Variable. Depending on the size of the SID. 173 The "Flags" and "SID/Index/Label" fields are the same as the 174 Prefix-SID sub-TLV [RFC8667]. 176 Algorithm: 1 octet. Associated algorithm. Algorithm values are 177 defined in the IGP Algorithm Type registry 179 SA-ID: Identifies a specific Slice Aggregate within the IGP 180 domain. 182 This sub-TLV MAY be present in any of the following TLVs: 184 TLV-135 (Extended IPv4 reachability) defined in [RFC5305]. 186 TLV-235 (Multitopology IPv4 Reachability) defined in [RFC5120]. 188 TLV-236 (IPv6 IP Reachability) defined in [RFC5308]. 190 TLV-237 (Multitopology IPv6 IP Reachability) defined in [RFC5120]. 192 This sub-TLV MAY appear multiple times in each TLV. 194 3.2. IS-IS Slice Aggregate Adjacency-SID Sub-TLV 196 [RFC8667] defines the IS-IS Adjacency Segment Identifier sub-TLV 197 (Adj-SID sub-TLV). The Adj-SID sub-TLV is an optional sub-TLV 198 carrying the Segment Routing IGP Adjacency-SID as defined in 199 [RFC8402]. 201 A new SR Slice Aggregate Adjacency-SID (SA Adj-SID) sub-TLV is 202 defined to allow a router to allocate and advertise multiple SA Adj- 203 SIDs towards the same IS-IS neighbor (adjacency). The SA Adj-SIDs 204 allows a router to enforce the specific treatment associated with the 205 Slice Aggregate. 207 The Slice Aggregate ID is carried in the SA Adj-SID sub-TLV to 208 associate it to the specific Slice Aggregate. The SA Adj-SID sub-TLV 209 has the following format: 211 0 1 2 3 212 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 1 213 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 214 | Type | Length | Flags | Weight | 215 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 216 | SA-ID | 217 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 218 | SID/Index/Label(Variable) | 219 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 221 Figure 2: SA Adj-SID sub-TLV for SR-MPLS. 223 where: 225 Type: TBD2 (Suggested value to be assigned by IANA) 227 Length: Variable. Depending on the size of the SID. 229 The "Flags" and "SID/Index/Label" fields are the same as the Adj- 230 SID sub-TLV [RFC8667]. 232 SA-ID: Identifies a specific Slice Aggregate within the IGP 233 domain. 235 This sub-TLV MAY be present in any of the following TLVs: 237 TLV-22 (Extended IS reachability) [RFC5305]. 239 TLV-222 (Multitopology IS) [RFC5120]. 241 TLV-23 (IS Neighbor Attribute) [RFC5311]. 243 TLV-223 (Multitopology IS Neighbor Attribute) [RFC5311]. 245 TLV-141 (inter-AS reachability information) [RFC5316]. 247 Multiple Adj-SID sub-TLVs MAY be associated with a single IS-IS 248 neighbor. This sub-TLV MAY appear multiple times in each TLV. 250 3.3. IS-IS Slice Aggregate LAN Adjacency-SIDs 252 In LAN subnetworks, [RFC8667] defines the SR-MPLS LAN-Adj-SID sub-TLV 253 for a router to advertise the Adj-SID of each of its neighbors. 255 A new SR Slice Aggregate LAN Adjacency-SID (SA LAN-Adj-SID) sub-TLV 256 is defined to allow a router to allocate and advertise multiple SA 257 LAN-Adj-SIDs towards each of its neighbors on the LAN. The SA LAN- 258 Adj-SIDs allows a router to enforce the specific treatment associated 259 with the specific Slice Aggregate towards a neighbor. 261 The Slice Aggregate ID is carried in the SA LAN-Adj-SID sub-TLV to 262 associate it to the specific Slice Aggregate. The SA LAN-Adj-SID 263 sub-TLV has the following format: 265 0 1 2 3 266 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 1 267 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 268 | Type=TBD3 | Length | Flags | Weight | 269 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 270 | SA-ID | 271 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 273 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 274 | Neighbor System-ID (ID length octets) | 275 + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 276 | | 277 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 279 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 280 | SID/Label/Index (variable) | 281 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 283 Figure 3: SA LAN Adj-SID sub-TLV for SR-MPLS. 285 where: 287 Type: TBD3 (Suggested value to be assigned by IANA) 289 Length: Variable. Depending on the size of the SID. 291 The "Flags" and "SID/Index/Label" fields are the same as the LAN- 292 Adj-SID sub-TLV [RFC8667]. 294 SA-ID: Identifies a specific Slice Aggregate within the IGP 295 domain. 297 This sub-TLV MAY be present in any of the following TLVs: 299 TLV-22 (Extended IS reachability) [RFC5305]. 301 TLV-222 (Multitopology IS) [RFC5120]. 303 TLV-23 (IS Neighbor Attribute) [RFC5311]. 305 TLV-223 (Multitopology IS Neighbor Attribute) [RFC5311]. 307 Multiple LAN-Adj-SID sub-TLVs MAY be associated with a single IS-IS 308 neighbor. This sub-TLV MAY appear multiple times in each TLV. 310 Editor Note: the OSPF Sub-TLV sections will be populated in 311 further update. 313 4. Slice Aggregate SIDs for SRv6 315 Segment Routing can be directly instantiated on the IPv6 data plane 316 through the use of the Segment Routing Header defined in [RFC8754]. 317 SRv6 refers to this SR instantiation on the IPv6 dataplane. 319 The SRv6 Locator TLV was introduced in 320 [I-D.ietf-lsr-isis-srv6-extensions] to advertise SRv6 Locators and 321 End SIDs associated with each locator. 323 4.1. SRv6 SID Slice Aggregate Sub-Sub-TLV 325 The SRv6 End SID sub-TLV was introduced in 326 [I-D.ietf-lsr-isis-srv6-extensions] to advertise SRv6 Segment 327 Identifiers (SID) with Endpoint behaviors which do not require a 328 particular neighbor. 330 The SRv6 End SID sub-TLV is advertised in the SRv6 Locator TLV, and 331 inherits the topology/algorithm from the parent locator. The SRv6 332 End SID sub-TLV defined in [I-D.ietf-lsr-isis-srv6-extensions] 333 carries optional sub-sub-TLVs. 335 A new SRv6 Slice Aggregate (SA) SID Sub-Sub-TLV is defined to allow a 336 router to assign and advertise an SRv6 End SID that is associated 337 with a specific Slice Aggregate. The SRv6 SID SA Sub-Sub-TLV allows 338 routers to infer and enforce the specific treatment associated with 339 the Slice Aggregate on the selected next-hops along the path to the 340 End SID destination. 342 0 1 2 3 343 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 1 344 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 345 | Type=TBD4 | Length | 346 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 347 | SA-ID | 348 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 350 Figure 4: SRv6 SID SA Sub-Sub-TLV format for SRv6. 352 where: 354 Type: TBD4 356 Length: 4 octets. 358 SA-ID: Identifies a specific Slice Aggregate within the IGP 359 domain. 361 ISIS SRv6 SID SA Sub-Sub-TLV MUST NOT appear more than once in its 362 parent Sub-TLV. If it appears more than once in its parent Sub- TLV, 363 the parent Sub-TLV MUST be ignored by the receiver. 365 The new SRv6 SID SA Sub-Sub-TLV is an optional Sub-Sub-TLV of: 367 SRv6 End SID Sub-TLV (Section 7.2 of 368 [I-D.ietf-lsr-isis-srv6-extensions]) 370 SRv6 End.X SID Sub-TLV (Section 8.1 of 371 [I-D.ietf-lsr-isis-srv6-extensions]) 373 SRv6 LAN End.X SID Sub-TLV (Section 8.2 of 374 [I-D.ietf-lsr-isis-srv6-extensions]) 376 5. IANA Considerations 378 This document requests allocation for the following Sub-TLVs. 380 5.1. SR Slice Aggregate Prefix-SID sub-TLV 382 This TLV shares sub-TLV space with existing "Sub-TLVs for TLVs 383 135,235,226 and 237 registry". 385 Type: TBD1 (to be assigned by IANA). 387 5.2. SR Slice Aggregate Adjacency-SID sub-TLV 389 This TLV shares sub-TLV space with existing "Sub-TLVs for TLVs 22, 390 222, 23, 223 and 141 registry". 392 Type: TBD2 (to be assigned by IANA). 394 5.3. SR Slice Aggregate LAN-Adj-SID sub-TLV 396 This TLV shares sub-TLV space with existing "Sub-TLVs for TLVs 22, 397 222, 23, and 223 registry". 399 Type: TBD3 (to be assigned by IANA). 401 5.4. SRv6 SID Slice Aggregate Sub-Sub-TLV 403 Type: TBD4 (to be assigned by IANA). 405 6. Security Considerations 407 TBD. 409 7. Acknowledgement 411 The authors would like to thank Swamy SRK, and Prabhu Raj Villadathu 412 Karunakaran for their review of this document, and for providing 413 valuable feedback on it. 415 8. Contributors 417 The following individuals contributed to this document: 419 Colby Barth 420 Juniper Networks 421 Email: cbarth@juniper.net 423 Srihari R. Sangli 424 Juniper Networks 425 Email: ssangli@juniper.net 427 Chandra Ramachandran 428 Juniper Networks 429 Email: csekar@juniper.net 431 9. References 433 9.1. Normative References 435 [I-D.bestbar-spring-scalable-ns] 436 Saad, T. and V. Beeram, "Scalable Network Slicing over SR 437 Networks", draft-bestbar-spring-scalable-ns-00 (work in 438 progress), December 2020. 440 [I-D.bestbar-teas-ns-packet] 441 Saad, T., Beeram, V., Wen, B., Ceccarelli, D., Halpern, 442 J., Peng, S., Chen, R., and X. Liu, "Realizing Network 443 Slices in IP/MPLS Networks", draft-bestbar-teas-ns- 444 packet-01 (work in progress), December 2020. 446 [I-D.ietf-lsr-isis-srv6-extensions] 447 Psenak, P., Filsfils, C., Bashandy, A., Decraene, B., and 448 Z. Hu, "IS-IS Extension to Support Segment Routing over 449 IPv6 Dataplane", draft-ietf-lsr-isis-srv6-extensions-11 450 (work in progress), October 2020. 452 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 453 Requirement Levels", BCP 14, RFC 2119, 454 DOI 10.17487/RFC2119, March 1997, 455 . 457 [RFC5120] Przygienda, T., Shen, N., and N. Sheth, "M-ISIS: Multi 458 Topology (MT) Routing in Intermediate System to 459 Intermediate Systems (IS-ISs)", RFC 5120, 460 DOI 10.17487/RFC5120, February 2008, 461 . 463 [RFC5305] Li, T. and H. Smit, "IS-IS Extensions for Traffic 464 Engineering", RFC 5305, DOI 10.17487/RFC5305, October 465 2008, . 467 [RFC5308] Hopps, C., "Routing IPv6 with IS-IS", RFC 5308, 468 DOI 10.17487/RFC5308, October 2008, 469 . 471 [RFC5311] McPherson, D., Ed., Ginsberg, L., Previdi, S., and M. 472 Shand, "Simplified Extension of Link State PDU (LSP) Space 473 for IS-IS", RFC 5311, DOI 10.17487/RFC5311, February 2009, 474 . 476 [RFC5316] Chen, M., Zhang, R., and X. Duan, "ISIS Extensions in 477 Support of Inter-Autonomous System (AS) MPLS and GMPLS 478 Traffic Engineering", RFC 5316, DOI 10.17487/RFC5316, 479 December 2008, . 481 [RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 482 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, 483 May 2017, . 485 [RFC8402] Filsfils, C., Ed., Previdi, S., Ed., Ginsberg, L., 486 Decraene, B., Litkowski, S., and R. Shakir, "Segment 487 Routing Architecture", RFC 8402, DOI 10.17487/RFC8402, 488 July 2018, . 490 [RFC8667] Previdi, S., Ed., Ginsberg, L., Ed., Filsfils, C., 491 Bashandy, A., Gredler, H., and B. Decraene, "IS-IS 492 Extensions for Segment Routing", RFC 8667, 493 DOI 10.17487/RFC8667, December 2019, 494 . 496 [RFC8754] Filsfils, C., Ed., Dukes, D., Ed., Previdi, S., Leddy, J., 497 Matsushima, S., and D. Voyer, "IPv6 Segment Routing Header 498 (SRH)", RFC 8754, DOI 10.17487/RFC8754, March 2020, 499 . 501 9.2. Informative References 503 [I-D.ietf-teas-ietf-network-slice-definition] 504 Rokui, R., Homma, S., Makhijani, K., Contreras, L., and J. 505 Tantsura, "Definition of IETF Network Slices", draft-ietf- 506 teas-ietf-network-slice-definition-00 (work in progress), 507 January 2021. 509 [I-D.nsdt-teas-ns-framework] 510 Gray, E. and J. Drake, "Framework for Transport Network 511 Slices", draft-nsdt-teas-ns-framework-04 (work in 512 progress), July 2020. 514 Authors' Addresses 516 Tarek Saad 517 Juniper Networks 519 Email: tsaad@juniper.net 521 Vishnu Pavan Beeram 522 Juniper Networks 524 Email: vbeeram@juniper.net 526 Ran Chen 527 ZTE Corporation 529 Email: chen.ran@zte.com.cn 531 Shaofu Peng 532 ZTE Corporation 534 Email: peng.shaofu@zte.com.cn 536 Bin Wen 537 Comcast 539 Email: Bin_Wen@cable.comcast.com 541 Daniele Ceccarelli 542 Ericsson 544 Email: daniele.ceccarelli@ericsson.com