idnits 2.17.1 draft-zch-lsr-isis-network-slicing-06.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 : ---------------------------------------------------------------------------- ** The abstract seems to contain references ([I-D.nsdt-teas-ns-framework]), which it shouldn't. Please replace those with straight textual mentions of the documents in question. Miscellaneous warnings: ---------------------------------------------------------------------------- == The copyright year in the IETF Trust and authors Copyright Line does not match the current year == Using lowercase 'not' together with uppercase 'MUST', 'SHALL', 'SHOULD', or 'RECOMMENDED' is not an accepted usage according to RFC 2119. Please use uppercase 'NOT' together with RFC 2119 keywords (if that is what you mean). Found 'MUST not' in this paragraph: When AII is 0, the URBPTSI Sub-TLV has the same function with the URB Sub-TLV defined in [RFC8570]. Note that the sum of URBPTSI Sub-TLV for all slices MUST not be larger than the result of Maximum Link Bandwidth [RFC5305] minus RSVP-TE tunnel reservations. == Using lowercase 'not' together with uppercase 'MUST', 'SHALL', 'SHOULD', or 'RECOMMENDED' is not an accepted usage according to RFC 2119. Please use uppercase 'NOT' together with RFC 2119 keywords (if that is what you mean). Found 'MUST not' in this paragraph: Note that[I-D.ietf-lsr-flex-algo].also allows user to define other algorithm values, i.e., FA-id within [128, 255], for the purpose of constraint based path computation. However, an FA-id algorithm value MUST not be set in this field, the reason is that FA-id has not semantic local within AII. -- The document date (September 05, 2020) is 1328 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) -- Looks like a reference, but probably isn't: '128' on line 442 -- Looks like a reference, but probably isn't: '255' on line 442 == Unused Reference: 'RFC2119' is defined on line 667, but no explicit reference was found in the text == Outdated reference: A later version (-26) exists of draft-ietf-lsr-flex-algo-10 == Outdated reference: A later version (-05) exists of draft-nsdt-teas-ns-framework-04 ** Downref: Normative reference to an Informational draft: draft-nsdt-teas-ns-framework (ref. 'I-D.nsdt-teas-ns-framework') ** Obsolete normative reference: RFC 5316 (Obsoleted by RFC 9346) == Outdated reference: A later version (-04) exists of draft-peng-teas-network-slicing-03 Summary: 3 errors (**), 0 flaws (~~), 7 warnings (==), 3 comments (--). Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 2 Networking Working Group Y. Zhu 3 Internet-Draft China Telecom 4 Intended status: Standards Track R. Chen 5 Expires: March 9, 2021 S. Peng 6 ZTE Corporation 7 F. Qin 8 China Mobile 9 September 05, 2020 11 IS-IS Extensions to Support Transport Network Slices using Segment 12 Routing 13 draft-zch-lsr-isis-network-slicing-06 15 Abstract 17 [I-D.nsdt-teas-ns-framework] provides a framework of transport 18 slices. 20 This draft describes the IS-IS extensions required to support 21 transport slices using Segment Routing. 23 Status of This Memo 25 This Internet-Draft is submitted in full conformance with the 26 provisions of BCP 78 and BCP 79. 28 Internet-Drafts are working documents of the Internet Engineering 29 Task Force (IETF). Note that other groups may also distribute 30 working documents as Internet-Drafts. The list of current Internet- 31 Drafts is at https://datatracker.ietf.org/drafts/current/. 33 Internet-Drafts are draft documents valid for a maximum of six months 34 and may be updated, replaced, or obsoleted by other documents at any 35 time. It is inappropriate to use Internet-Drafts as reference 36 material or to cite them other than as "work in progress." 38 This Internet-Draft will expire on March 9, 2021. 40 Copyright Notice 42 Copyright (c) 2020 IETF Trust and the persons identified as the 43 document authors. All rights reserved. 45 This document is subject to BCP 78 and the IETF Trust's Legal 46 Provisions Relating to IETF Documents 47 (https://trustee.ietf.org/license-info) in effect on the date of 48 publication of this document. Please review these documents 49 carefully, as they describe your rights and restrictions with respect 50 to this document. Code Components extracted from this document must 51 include Simplified BSD License text as described in Section 4.e of 52 the Trust Legal Provisions and are provided without warranty as 53 described in the Simplified BSD License. 55 Table of Contents 57 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3 58 2. Conventions used in this document . . . . . . . . . . . . . . 3 59 3. Router Capabilities for TN-slice Identifier . . . . . . . . . 3 60 4. Advertising TN-slice Identifier as a new TE parameter of a 61 link . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 62 4.1. Advertising Dedicated Bandwidth Resouce of a Link for 63 Each VN . . . . . . . . . . . . . . . . . . . . . . . . . 5 64 4.1.1. Unidirectional Residual Bandwidth per TN-slice 65 Identifier Sub-TLV . . . . . . . . . . . . . . . . . 6 66 4.1.2. Unidirectional Available Bandwidth per TN-slice 67 Identifier Sub-TLV . . . . . . . . . . . . . . . . . 7 68 4.1.3. Unidirectional Utilized Bandwidth per TN-slice 69 Identifier Sub-TLV . . . . . . . . . . . . . . . . . 8 70 5. Advertising TN-slice Identifier for L2 Bundle Member . . . . 8 71 5.1. Advertising Bandwidth Information of member Link . . . . 9 72 6. Advertising prefix-SID per TN-slice Identifier . . . . . . . 9 73 7. Advertising Adjacency-SID per TN-slice Identifier . . . . . . 11 74 8. Advertising Adjacency-SID per TN-slice Identifier in LANs . . 12 75 9. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 13 76 9.1. Router Capabilities for TN-slice Identifier . . . . . . . 13 77 9.2. TN-slice Identifier list sub-TLV . . . . . . . . . . . . 13 78 9.3. Unidirectional Residual Bandwidth per TN-slice Identifier 79 Sub-TLV . . . . . . . . . . . . . . . . . . . . . . . . . 13 80 9.4. Unidirectional Available Bandwidth per TN-slice 81 Identifier Sub-TLV . . . . . . . . . . . . . . . . . . . 14 82 9.5. Unidirectional Utilized Bandwidth per TN-slice Identifier 83 Sub-TLV . . . . . . . . . . . . . . . . . . . . . . . . . 14 84 9.6. L2 Bundle Member TN-slice Identifier sub-TLV . . . . . . 14 85 9.7. Prefix-SID for TN-slice Identifier sub-TLV . . . . . . . 14 86 9.8. Adjacency-SID for TN-slice Identifier sub-TLV . . . . . . 14 87 9.9. LAN-Adj-SID for TN-slice Identifier sub-TLV . . . . . . . 14 88 10. Security Considerations . . . . . . . . . . . . . . . . . . . 15 89 11. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 15 90 12. References . . . . . . . . . . . . . . . . . . . . . . . . . 15 91 12.1. Normative references . . . . . . . . . . . . . . . . . . 15 92 12.2. Informative references . . . . . . . . . . . . . . . . . 16 93 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 16 95 1. Introduction 97 [I-D.nsdt-teas-ns-framework] provides a framework for discussing 98 transport slices. 100 For a Transport Network, transport network slicing requires the 101 underlying network to support partitioning of the network resources 102 to provide the client with dedicated (private) networking, computing, 103 and storage resources drawn from a shared pool. 104 [I-D.peng-teas-network-slicing] introduce a unified TN-slice 105 identifier (termes as AII) to the underlay transport network 106 according to the requirement of network slice. AII is convenient to 107 indicate the topology, computing, storage resources of the dedicated 108 virtual network for both intra-domain and inter-domain network 109 slicing scenarios, and it is flexible to compute SR-BE or SR-TE path 110 according to AII combined with other creteria. 112 This draft describes the IS-IS extensions required to distribute TN- 113 slice Identifier information in an AS. 115 2. Conventions used in this document 117 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 118 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this 119 document are to be interpreted as described in RFC2119. 121 3. Router Capabilities for TN-slice Identifier 123 Although a router can deduce which TN-slices it has participated in 124 according to the AII(administrative instance identifier) 125 configuration of all links, an ISIS instance can explicitly control 126 which TN-slices it wants to enable (or join), to explicitly control 127 which SPT (shortest path tree) for a specific AII to be created. It 128 is possible for a route process not to join any TN-slices (except the 129 default AII 0) in despite of any AII configuration of any links. 130 Especially, it is hard to deduce the participated TN-slice according 131 to the AII configuration of L2 Bundle Member. 133 This section defines AII Participation sub-TLV which is inserted into 134 the IS-IS Router Capability TLV-242 that is defined in [RFC7981], to 135 explicitly advertise which TN-slice a router wants to take part in. 137 The TN-slice identifier Participation sub-TLV has the following 138 format: 140 0 1 2 3 141 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 1 142 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 143 | Type=TBD1 | Length | Number | | 144 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 145 | AII for virtual networks 1 | 146 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 147 | ...... | 148 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 149 | AII for virtual networks N | 150 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 152 Figure 1: Node Participation to TN-slice 154 where: 156 Type: TBD1 (Suggested value to be assigned by IANA) 158 Length: variable. 160 Number:Number of virtual networks. 162 AII for VN: allocate different TN-slice identifier (AII) for 163 different virtual networks. AII is used to distinguish different 164 virtual network resources. 166 4. Advertising TN-slice Identifier as a new TE parameter of a link 168 [RFC5305] describes extensions to the Intermediate System to 169 Intermediate System (IS-IS) protocol to support Traffic Engineering 170 (TE). 172 TN-slice Identifier can be used to color links to partition underlay 173 resource. This document defines a new extension of the existing IGP- 174 TE mechanisms [RFC5305] to distribute TN-slice Identifier information 175 in an AS as a new TE parameter of a link. 177 The TN-slice Identifier list sub-TLV has the following format: 179 0 1 2 3 180 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 1 181 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 182 | Type=TBD2 | Length | Reserved | Number | 183 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 184 | AII for virtual networks 1 | 185 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 186 | ...... | 187 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 188 | AII for virtual networks N | 189 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 191 Figure 2: Link Participation to TN-slice 193 Type: TBD2 (Suggested value to be assigned by IANA) 195 Length: variable. 197 Number:Number of virtual networks. 199 AII for VN: allocate different TN-slice identifier (AII) for 200 different virtual networks. AII is used to distinguish different 201 virtual network resources. 203 This sub-TLV MAY be present in any of the following TLVs: 205 TLV-22 (Extended IS reachability) [RFC5305]. 207 TLV-222 (Multitopology IS) [RFC5120]. 209 TLV-23 (IS Neighbor Attribute) [RFC5311]. 211 TLV-223 (Multitopology IS Neighbor Attribute) [RFC5311]. 213 TLV-141 (inter-AS reachability information) [RFC5316]. 215 This sub-TLV SHOULD appear once at most in each TLV. Indicates that 216 a link MAY belong to multiple virtual networks. 218 Note that AII 0 does not require notification, and all links are 219 always in AII 0 at the same time. 221 4.1. Advertising Dedicated Bandwidth Resouce of a Link for Each VN 223 [RFC8570] provide ways to distribute network-performance information, 224 and it defines Unidirectional Residual Bandwidth Sub-TLV (URB Sub- 225 TLV), Unidirectional Available Bandwidth Sub-TLV (UAB Sub-TLV), 226 Unidirectional Utilized Bandwidth Sub-TLV (UUB Sub-TLV) for each 227 directly connected IS-IS neighbors. As described above, a link can 228 belong to multiple VNs, as traditional ways that these VNs can share 229 the total bandwidth resouce of the link with preemption mode based on 230 packet priority, this is what we know as soft slices. However, In 231 some other scenarios, a hard slicing scheme can be used to establish 232 a hardened pipe to meet the slicing business requirements, at this 233 time each VN need dedicated bandwidth resouce reserved from the same 234 link, and in each node the packet rate limit and QoS policy per slice 235 may be used to ensure that the traffic between different slices is 236 isolated and does not affect each other. For this purpose, this 237 section continues to introduce and register new bandwidth related IS- 238 IS TE sub-TLVs in the "Sub-TLVs for TLVs 22, 23, 141, 222, and 223" 239 registry. 241 4.1.1. Unidirectional Residual Bandwidth per TN-slice Identifier Sub- 242 TLV 244 This sub-TLV (URBPTSI Sub-TLV) advertises the residual bandwidth for 245 a specific slice between two directly connected IS-IS neighbors. The 246 residual bandwidth advertised by this sub-TLV MUST be the residual 247 bandwidth from the system originating the Link State Advertisement 248 (LSA) to its neighbor. This sub-TLV may appear more than once. 250 0 1 2 3 251 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 1 252 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 253 | Type=TBD3 | Length | 254 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 255 | AII | 256 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 257 | Residual Bandwidth | 258 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 260 Figure 3: Unidirectional Residual Bandwidth per TN-slice 262 Type: TBD3 (Suggested value to be assigned by IANA) 264 Length: 8 266 AII: Identifies the TN-slice information. 268 Residual Bandwidth: This field carries the residual bandwidth for 269 specific TN-slice on a link or bundled link in IEEE floating-point 270 format with units of bytes per second. 272 When AII is 0, the URBPTSI Sub-TLV has the same function with the URB 273 Sub-TLV defined in [RFC8570]. Note that the sum of URBPTSI Sub-TLV 274 for all slices MUST not be larger than the result of Maximum Link 275 Bandwidth [RFC5305] minus RSVP-TE tunnel reservations. 277 For the system originating the URBPTSI Sub-TLV, the residual 278 bandwidth for each specific slice could be configured explicitly. 279 For example, for a link with 10G bandwidth without any RSVP-TE tunnel 280 reservations, the configuration could be: 4G is allocated for AII 1, 281 4G is allocated for AII 2, then the rest 2G is allocated for AII 0. 282 Thus, an URBPTSI Sub-TLV for AII 0 or traditional URB Sub-TLV with 283 Residual Bandwidth field set to 2G can be advertised, and two URBPTSI 284 Sub-TLVs each for AII 1 or 2 with Residual Bandwidth field set to 4G 285 can be advertised respectively. 287 4.1.2. Unidirectional Available Bandwidth per TN-slice Identifier Sub- 288 TLV 290 This sub-TLV (UABPTSI Sub-TLV) advertises the available bandwidth for 291 a specific slice between two directly connected IS-IS neighbors. The 292 available bandwidth advertised by this sub-TLV MUST be the available 293 bandwidth from the system originating this sub-TLV. This sub-TLV may 294 appear more than once. The format of this sub-TLV is shown in the 295 following diagram: 297 0 1 2 3 298 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 1 299 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 300 | Type=TBD4 | Length | 301 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 302 | AII | 303 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 304 | Available Bandwidth | 305 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 307 Figure 4: Unidirectional Available Bandwidth per TN-slice 309 Type: TBD4 (Suggested value to be assigned by IANA) 311 Length: 8 313 AII: Identifies the TN-slice information. 315 Available Bandwidth: This field carries the available bandwidth for 316 specific TN-slice on a link or bundled link in IEEE floating-point 317 format with units of bytes per second. It is defined to be residual 318 bandwidth per TN-slice minus the measured bandwidth (the UUBPTSI 319 introduced in next section) used for the actual forwarding of packets 320 within that slice. 322 4.1.3. Unidirectional Utilized Bandwidth per TN-slice Identifier Sub- 323 TLV 325 This sub-TLV (UUBPTSI Sub-TLV) advertises the bandwidth utilization 326 for a specific slice between two directly connected IS-IS neighbors. 327 The bandwidth utilization advertised by this sub-TLV MUST be the 328 bandwidth from the system originating this sub-TLV. This sub-TLV may 329 appear more than once. The format of this sub-TLV is shown in the 330 following diagram: 332 0 1 2 3 333 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 1 334 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 335 | Type=TBD5 | Length | 336 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 337 | AII | 338 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 339 | Utilized Bandwidth | 340 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 342 Figure 5: Unidirectional Utilized Bandwidth per TN-slice 344 Type: TBD5 (Suggested value to be assigned by IANA) 346 Length: 8 348 AII: Identifies the TN-slice information. 350 Utilized Bandwidth: This field carries the bandwidth utilization for 351 specific TN-slice on a link or bundled link in IEEE floating-point 352 format with units of bytes per second. It represents the actual 353 utilization of the link (i.e., as measured by the advertising node) 354 for that slice. 356 5. Advertising TN-slice Identifier for L2 Bundle Member 358 [RFC8668] defines a sub-TLV of L2 Bundle Attribute Descriptors, and 359 the sub-TLV may define an attribute common to all of the bundle 360 members listed or a sub-TLV may define an attribute unique to each 361 bundle member. For a bundled link, there are two ways to use TN- 362 slice Identifier to partition its resource. The first one is to set 363 the parent interface with one or more expected TN-slice Identifier, 364 that is we have seen in Section 4. The second one is to set each 365 member interface with specific TN-slice Identifier, for example, 366 member 1 set to AII 0, member 2 set to AII 1, member 3 set to AII 2, 367 etc. For simple deployment and according to actual needs, each 368 member is set to a single TN-slice Identifier. For the second case, 369 this section defines a new sub-TLV: L2 Bundle Member TN-slice 370 Identifier sub-TLV, to advertise TN-slice Identifier for each L2 371 Bundle Member associated with a parent L3 adjacency which is Point- 372 to-Point. The following format is defined for this sub-TLV: 374 Type: TBD6. 376 Length: variable 378 L2 Bundle Member TN-slice Identifier. There MUST be one TN-slice 379 Identifier(AII) for each of the L2 Bundle Members advertised under 380 the preceding L2 Bundle Member Attribute Descriptor. 382 This sub-TLV MAY be present in the following TLVs: 384 TLV-25 (L2 Bundle Member Attributes) [RFC8668]. 386 This sub-TLV SHOULD appear once at most in the TLV. Indicates that 387 the TN-slice Identifier for L2 Bundle Member. 389 5.1. Advertising Bandwidth Information of member Link 391 [RFC8668] allows notification of bandwidth information of member 392 links using the sub-TLVs defined in [RFC8570]. Because each member 393 link belongs to single TN-slice, it is not necessary to advertise the 394 bandwidth information of member links for specific slice using the 395 sub-TLVs defined in Section 4.1. 397 6. Advertising prefix-SID per TN-slice Identifier 399 [RFC8667] defines a new IS-IS sub-TLV: the Prefix Segment Identifier 400 sub-TLV (Prefix-SID sub-TLV). The Prefix-SID sub-TLV carries the 401 Segment Routing IGP-Prefix-SID as defined in [RFC8402], and is 402 associated to a prefix advertised by a node. 404 To distinguish forwarding behavior of different virtual networks, 405 Prefix-SID need to be allocated per TN-slice Identifier and 406 advertised in the IGP domain. This document defines a new extension 407 of the existing Prefix-SID sub-TLV. 409 The Prefix-SID for TN-slice Identifier sub-TLV has the following 410 format: 412 0 1 2 3 413 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 1 414 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 415 | Type=TBD7 | Length | Flag | Algorithm | 416 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 417 | AII | 418 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 419 | SID/Index/Label(Variable) | 420 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 422 Figure 6: Prefix-SID per TN-slice 424 where: 426 Type: TBD7 (Suggested value to be assigned by IANA) 428 Length: Variable. Depending on the size of the SID. 430 The "Flags" and "SID/Index/Label" fields are the same as the Prefix- 431 SID sub-TLV [RFC8667] . 433 Algorithm: Accoridng to section "3.2. SR-Algorithm Sub-TLV" of 434 [RFC8667] , two values can be set in this field. 436 o 0: Shortest Path First (SPF) algorithm based on link metric. 438 o 1: Strict Shortest Path First (SPF) algorithm based on link 439 metric. 441 Note that[I-D.ietf-lsr-flex-algo].also allows user to define other 442 algorithm values, i.e., FA-id within [128, 255], for the purpose of 443 constraint based path computation. However, an FA-id algorithm value 444 MUST not be set in this field, the reason is that FA-id has not 445 semantic local within AII. 447 AII: Identifies the TN-slice (AII) information corresponding to the 448 Prefix-SID. 450 This sub-TLV MAY be present in any of the following TLVs: 452 TLV-135 (Extended IPv4 reachability) defined in [RFC5305]. 454 TLV-235 (Multitopology IPv4 Reachability) defined in [RFC5120]. 456 TLV-236 (IPv6 IP Reachability) defined in [RFC5308]. 458 TLV-237 (Multitopology IPv6 IP Reachability) defined in [RFC5120]. 460 This sub-TLV MAY appear multiple times in each TLV. 462 7. Advertising Adjacency-SID per TN-slice Identifier 464 [RFC8667] defines the IS-IS sub-TLV: the Adjacency Segment Identifier 465 sub-TLV (Adj-SID sub-TLV).The Adj-SID sub-TLV is an optional sub-TLV 466 carrying the Segment Routing IGP-Adjacency-SID as defined in 467 [RFC8402]. 469 To distinguish forwarding behavior of different virtual networks, 470 Adjacency-SID need to be allocated per TN-slice Identifier and 471 advertised in the IGP domain. This document defines a new extension 472 of the existing Adjacency-SID sub-TLV. 474 The Adjacency-SID for TN-slice Identifier sub-TLV has the following 475 format: 477 0 1 2 3 478 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 1 479 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 480 | Type=TBD8 | Length | Flag | Algorithm | 481 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 482 | AII | 483 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 484 | SID/Index/Label(Variable) | 485 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 487 Figure 7: Adjacency-SID per TN-slice 489 where: 491 Type: TBD8 (Suggested value to be assigned by IANA) 493 Length: Variable. Depending on the size of the SID. 495 The "Flags" and "SID/Index/Label" fields are the same as the 496 Adjacency-SID sub-TLV [RFC8667]. 498 AII: Identifies the TN-slice (AII) information corresponding to the 499 Adjacency-SID. 501 This sub-TLV MAY be present in any of the following TLVs: 503 TLV-22 (Extended IS reachability) [RFC5305]. 505 TLV-222 (Multitopology IS)[RFC5120]. 507 TLV-23 (IS Neighbor Attribute)[RFC5311]. 509 TLV-223 (Multitopology IS Neighbor Attribute)[RFC5311]. 511 TLV-141 (inter-AS reachability information)[RFC5316]. 513 Multiple Adj-SID sub-TLVs MAY be associated with a single IS- 514 neighbor. This sub-TLV MAY appear multiple times in each TLV. 516 8. Advertising Adjacency-SID per TN-slice Identifier in LANs 518 In LAN subnetworks,[RFC8667] defines the LAN-Adj-SID sub-TLV for a 519 router to advertise the Adj-SID of each of its neighbors. 521 To distinguish forwarding behavior of different virtual networks, 522 Adjacency-SID need to be allocated per TN-slice Identifier and 523 advertised in the IGP domain. This document defines a new extension 524 of the existing Adjacency-SID sub-TLV. 526 The LAN-Adj-SID for TN-slice Identifier sub-TLV has the following 527 format: 529 0 1 2 3 530 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 1 531 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 532 | Type=TBD9 | Length | Flags | Weight | 533 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 535 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 536 | Neighbor System-ID (ID length octets) | 537 + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 538 | | 539 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 540 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 541 | AII | 542 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 543 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 544 | SID/Label/Index (variable) | 545 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 547 Figure 8: Adjacency-SID per TN-slice in LANs 549 where: 551 Type: TBD9 (Suggested value to be assigned by IANA) 552 Length: Variable. Depending on the size of the SID. 554 The "Flags" and "SID/Index/Label" fields are the same as the 555 Adjacency-SID sub-TLV [RFC8667]. 557 AII: Identifies the TN-slice (AII) information corresponding to the 558 Adjacency-SID. 560 This sub-TLV MAY be present in any of the following TLVs: 562 TLV-22 (Extended IS reachability) [RFC5305]. 564 TLV-222 (Multitopology IS)[RFC5120]. 566 TLV-23 (IS Neighbor Attribute)[RFC5311]. 568 TLV-223 (Multitopology IS Neighbor Attribute)[RFC5311]. 570 Multiple Adj-SID sub-TLVs MAY be associated with a single IS- 571 neighbor. This sub-TLV MAY appear multiple times in each TLV. 573 9. IANA Considerations 575 This document requests allocation for the following Sub-TLVs. 577 9.1. Router Capabilities for TN-slice Identifier 579 This document requests IANA to assign a new code point in the "sub- 580 TLV for TLV 242" registry. 582 Type: TBD1 584 9.2. TN-slice Identifier list sub-TLV 586 This TLV shares sub-TLV space with existing "Sub-TLVs for TLVs 22, 587 222, 23, 223 and 141 registry". 589 Type:TBD2(to be assigned by IANA). 591 9.3. Unidirectional Residual Bandwidth per TN-slice Identifier Sub-TLV 593 This TLV shares sub-TLV space with existing "Sub-TLVs for TLVs 22, 594 222, 23, 223 and 141 registry". 596 Type:TBD3(to be assigned by IANA). 598 9.4. Unidirectional Available Bandwidth per TN-slice Identifier Sub-TLV 600 This TLV shares sub-TLV space with existing "Sub-TLVs for TLVs 22, 601 222, 23, 223 and 141 registry". 603 Type:TBD4(to be assigned by IANA). 605 9.5. Unidirectional Utilized Bandwidth per TN-slice Identifier Sub-TLV 607 This TLV shares sub-TLV space with existing "Sub-TLVs for TLVs 22, 608 222, 23, 223 and 141 registry". 610 Type:TBD5(to be assigned by IANA). 612 9.6. L2 Bundle Member TN-slice Identifier sub-TLV 614 This TLV shares sub-TLV space with existing "Sub-TLVs for TLVs 22, 615 222, 23, 25, 223 and 141 registry. 617 Type:TBD6(to be assigned by IANA). 619 This sub-TLV is allowed in the following TLVs: 621 22 23 25 141 222 223 622 n n y n n n 624 9.7. Prefix-SID for TN-slice Identifier sub-TLV 626 This TLV shares sub-TLV space with existing "Sub-TLVs for TLVs 627 135,235,226 and 237 registry". 629 Type:TBD7(to be assigned by IANA). 631 9.8. Adjacency-SID for TN-slice Identifier sub-TLV 633 This TLV shares sub-TLV space with existing "Sub-TLVs for TLVs 22, 634 222, 23, 223 and 141 registry". 636 Type:TBD8(to be assigned by IANA). 638 9.9. LAN-Adj-SID for TN-slice Identifier sub-TLV 640 This TLV shares sub-TLV space with existing "Sub-TLVs for TLVs 22, 641 222, 23, and 223 registry". 643 Type:TBD9(to be assigned by IANA). 645 10. Security Considerations 647 TBD. 649 11. Acknowledgements 651 TBD. 653 12. References 655 12.1. Normative references 657 [I-D.ietf-lsr-flex-algo] 658 Psenak, P., Hegde, S., Filsfils, C., Talaulikar, K., and 659 A. Gulko, "IGP Flexible Algorithm", draft-ietf-lsr-flex- 660 algo-10 (work in progress), August 2020. 662 [I-D.nsdt-teas-ns-framework] 663 Gray, E. and J. Drake, "Framework for Transport Network 664 Slices", draft-nsdt-teas-ns-framework-04 (work in 665 progress), July 2020. 667 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 668 Requirement Levels", BCP 14, RFC 2119, 669 DOI 10.17487/RFC2119, March 1997, 670 . 672 [RFC5120] Przygienda, T., Shen, N., and N. Sheth, "M-ISIS: Multi 673 Topology (MT) Routing in Intermediate System to 674 Intermediate Systems (IS-ISs)", RFC 5120, 675 DOI 10.17487/RFC5120, February 2008, 676 . 678 [RFC5305] Li, T. and H. Smit, "IS-IS Extensions for Traffic 679 Engineering", RFC 5305, DOI 10.17487/RFC5305, October 680 2008, . 682 [RFC5308] Hopps, C., "Routing IPv6 with IS-IS", RFC 5308, 683 DOI 10.17487/RFC5308, October 2008, 684 . 686 [RFC5311] McPherson, D., Ed., Ginsberg, L., Previdi, S., and M. 687 Shand, "Simplified Extension of Link State PDU (LSP) Space 688 for IS-IS", RFC 5311, DOI 10.17487/RFC5311, February 2009, 689 . 691 [RFC5316] Chen, M., Zhang, R., and X. Duan, "ISIS Extensions in 692 Support of Inter-Autonomous System (AS) MPLS and GMPLS 693 Traffic Engineering", RFC 5316, DOI 10.17487/RFC5316, 694 December 2008, . 696 [RFC7981] Ginsberg, L., Previdi, S., and M. Chen, "IS-IS Extensions 697 for Advertising Router Information", RFC 7981, 698 DOI 10.17487/RFC7981, October 2016, 699 . 701 [RFC8402] Filsfils, C., Ed., Previdi, S., Ed., Ginsberg, L., 702 Decraene, B., Litkowski, S., and R. Shakir, "Segment 703 Routing Architecture", RFC 8402, DOI 10.17487/RFC8402, 704 July 2018, . 706 [RFC8570] Ginsberg, L., Ed., Previdi, S., Ed., Giacalone, S., Ward, 707 D., Drake, J., and Q. Wu, "IS-IS Traffic Engineering (TE) 708 Metric Extensions", RFC 8570, DOI 10.17487/RFC8570, March 709 2019, . 711 [RFC8667] Previdi, S., Ed., Ginsberg, L., Ed., Filsfils, C., 712 Bashandy, A., Gredler, H., and B. Decraene, "IS-IS 713 Extensions for Segment Routing", RFC 8667, 714 DOI 10.17487/RFC8667, December 2019, 715 . 717 [RFC8668] Ginsberg, L., Ed., Bashandy, A., Filsfils, C., Nanduri, 718 M., and E. Aries, "Advertising Layer 2 Bundle Member Link 719 Attributes in IS-IS", RFC 8668, DOI 10.17487/RFC8668, 720 December 2019, . 722 12.2. Informative references 724 [I-D.peng-teas-network-slicing] 725 Peng, S., Chen, R., Mirsky, G., and F. Qin, "Packet 726 Network Slicing using Segment Routing", draft-peng-teas- 727 network-slicing-03 (work in progress), February 2020. 729 Authors' Addresses 731 Yongqing Zhu 732 China Telecom 734 Email: zhuyq.gd@chinatelecom.cn 735 Ran Chen 736 ZTE Corporation 738 Email: chen.ran@zte.com.cn 740 Shaofu Peng 741 ZTE Corporation 743 Email: peng.shaofu@zte.com.cn 745 Fengwei Qin 746 China Mobile 748 Email: qinfengwei@chinamobile.com