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Summary: 5 errors (**), 0 flaws (~~), 3 warnings (==), 2 comments (--). Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 2 Network Working Group K. Kompella (Editor) 3 Internet Draft Y. Rekhter (Editor) 4 Category: Informational Juniper Networks 5 Expires: June 2003 December 2002 7 IS-IS Extensions in Support of Generalized MPLS 9 draft-ietf-isis-gmpls-extensions-16.txt 11 Status of this Memo 13 This document is an Internet-Draft and is in full conformance with 14 all provisions of Section 10 of RFC2026. 16 Internet-Drafts are working documents of the Internet Engineering 17 Task Force (IETF), its areas, and its working groups. Note that 18 other groups may also distribute working documents as Internet- 19 Drafts. 21 Internet-Drafts are draft documents valid for a maximum of six months 22 and may be updated, replaced, or obsoleted by other documents at any 23 time. It is inappropriate to use Internet-Drafts as reference 24 material or to cite them other than as ``work in progress.'' 26 The list of current Internet-Drafts can be accessed at 27 http://www.ietf.org/ietf/1id-abstracts.txt 29 The list of Internet-Draft Shadow Directories can be accessed at 30 http://www.ietf.org/shadow.html. 32 Copyright Notice 34 Copyright (C) The Internet Society (2002). All Rights Reserved. 36 Abstract 38 This document specifies encoding of extensions to the IS-IS routing 39 protocol in support of Generalized Multi-Protocol Label Switching. 41 Summary for Sub-IP Area 43 (To be removed before publication) 45 0.1. Summary 47 This document specifies encoding of extensions to the IS-IS routing 48 protocol in support of Generalized Multi-Protocol Label Switching 49 (GMPLS). The description of the extensions is specified in [GMPLS- 50 ROUTING]. 52 0.2. Where does it fit in the Picture of the Sub-IP Work 54 This work fits squarely in either CCAMP or IS-IS boxes. 56 0.3. Why is it Targeted at this WG 58 This draft is targeted at either the CCAMP or IS-IS WGs, because this 59 draft specifies the extensions to the IS-IS routing protocols in 60 support of GMPLS, because GMPLS is within the scope of CCAMP WG, and 61 because IS-IS is within the scope of the IS-IS WG. 63 0.4. Justification 65 The WG should consider this document as it specifies the extensions 66 to the IS-IS routing protocols in support of GMPLS. 68 1. Specification of Requirements 70 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 71 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this 72 document are to be interpreted as described in RFC 2119 [RFC2119]. 74 2. Introduction 76 This document specifies extensions to the IS-IS routing protocol in 77 support of carrying link state information for Generalized Multi- 78 Protocol Label Switching (GMPLS). The set of required enhancements to 79 IS-IS are outlined in [GMPLS-ROUTING]. Support for unnumbered 80 interfaces assumes support for the "Point-to-Point Three-Way 81 Adjacency" IS-IS Option type [ISIS-3way]. 83 3. IS-IS Routing Enhancements 85 In this section we define the enhancements to the TE properties of 86 GMPLS TE links that can be announced in IS-IS Link State Protocol 87 Data Units. 89 In this document, we enhance the sub-TLVs for the extended IS 90 reachability TLV (see [ISIS-TE]) in support of GMPLS. Specifically, 91 we add the following sub-TLVs: 93 Sub-TLV Type Length Name 94 4 8 Link Local/Remote Identifiers 95 20 2 Link Protection Type 96 21 variable Interface Switching Capability Descriptor 98 We further add one new TLV to the TE TLVs: 100 TLV Type Length Name 101 138 variable Shared Risk Link Group 103 3.1. Link Local/Remote Identifiers 105 A Link Local Interface Identifiers is a sub-TLV of the extended IS 106 reachability TLV. The type of this sub-TLV is 4, and length is eight 107 octets. The value field of this sub-TLV contains four octets of Link 108 Local Identifier followed by four octets of Link Remote Idenfier (see 109 Section "Support for unnumbered links" of [GMPLS-ROUTING]). If the 110 Link Remote Identifier is unknown, it is set to 0. 112 The following illustrates encoding of the Value field of the Link 113 Local/Remote Identifiers sub-TLV. 115 0 1 2 3 116 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 1 117 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 118 | Link Local Identifier | 119 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 120 | Link Remote Identifier | 121 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 123 The Link Local/Remote Identifiers sub-TLV MUST NOT occur more than 124 once within the extended IS reachability TLV. If the Link 125 Local/Remote Idenfitiers sub-TLV occurs more than once within the 126 extended IS reachability TLV, the receiver SHOULD ignore all these 127 sub-TLVs. 129 3.2. Link Protection Type 131 The Link Protection Type is is a sub-TLV (of type 20) of the 132 extended IS reachability TLV, with length two octets. 134 The following illustrates encoding of the Value field of the Link 135 Protection Type sub-TLV. 137 0 1 138 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 139 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 140 |Protection Cap | Reserved | 141 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 143 The first octet is a bit vector describing the protection 144 capabilities of the link (see Section "Link Protection Type" of 145 [GMPLS-ROUTING]). They are: 147 0x01 Extra Traffic 149 0x02 Unprotected 151 0x04 Shared 153 0x08 Dedicated 1:1 155 0x10 Dedicated 1+1 157 0x20 Enhanced 159 0x40 Reserved 161 0x80 Reserved 162 The second octet SHOULD be set to zero by the sender, and SHOULD be 163 ignored by the receiver. 165 The Link Protection Type sub-TLV MUST NOT occur more than once within 166 the extended IS reachability TLV. If the Link Protection Type sub-TLV 167 occurs more than once within the extended IS reachability TLV, the 168 receiver SHOULD ignore all these sub-TLVs. 170 3.3. Interface Switching Capability Descriptor 172 The Interface Switching Capability Descriptor is a sub-TLV (of type 173 21) of the extended IS reachability TLV. The length is the length of 174 value field in octets. The following illustrates encoding of the 175 Value field of the Interface Switching Capability Descriptor sub-TLV. 177 0 1 2 3 178 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 1 179 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 180 | Switching Cap | Encoding | Reserved | 181 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 182 | Max LSP Bandwidth at priority 0 | 183 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 184 | Max LSP Bandwidth at priority 1 | 185 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 186 | Max LSP Bandwidth at priority 2 | 187 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 188 | Max LSP Bandwidth at priority 3 | 189 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 190 | Max LSP Bandwidth at priority 4 | 191 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 192 | Max LSP Bandwidth at priority 5 | 193 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 194 | Max LSP Bandwidth at priority 6 | 195 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 196 | Max LSP Bandwidth at priority 7 | 197 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 198 | Switching Capability-specific information | 199 | (variable) | 200 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 202 The Switching Capability (Switching Cap) field contains one of the 203 following values: 205 1 Packet-Switch Capable-1 (PSC-1) 206 2 Packet-Switch Capable-2 (PSC-2) 207 3 Packet-Switch Capable-3 (PSC-3) 208 4 Packet-Switch Capable-4 (PSC-4) 209 51 Layer-2 Switch Capable (L2SC) 210 100 Time-Division-Multiplex Capable (TDM) 211 150 Lambda-Switch Capable (LSC) 212 200 Fiber-Switch Capable (FSC) 214 The Encoding field contains one of the values specified in Section 215 3.1.1 of [GMPLS-SIG]. 217 Maximum LSP Bandwidth is encoded as a list of eight 4 octet fields in 218 the IEEE floating point format, with priority 0 first and priority 7 219 last. The units are bytes (not bits!) per second. 221 The content of the Switching Capability specific information field 222 depends on the value of the Switching Capability field. 224 When the Switching Capability field is PSC-1, PSC-2, PSC-3, or PSC-4, 225 the Switching Capability specific information field includes Minimum 226 LSP Bandwidth and Interface MTU. 228 0 1 2 3 229 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 1 230 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 231 | Minimum LSP Bandwidth | 232 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 233 | Interface MTU | 234 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 236 The Minimum LSP Bandwidth is is encoded in a 4 octets field in the 237 IEEE floating point format. The units are bytes (not bits!) per 238 second. The Interface MTU is encoded as a 2 octets integer, and 239 carries the MTU value in the units of bytes. 241 When the Switching Capability field is L2SC, there is no Switching 242 Capability specific information field present. 244 When the Switching Capability field is TDM, the Switching Capability 245 specific information field includes Minimum LSP Bandwidth and an 246 indication whether the interface supports Standard or Arbitrary 247 SONET/SDH. 249 0 1 2 3 250 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 1 251 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 252 | Minimum LSP Bandwidth | 253 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 254 | Indication | 255 +-+-+-+-+-+-+-+-+ 256 The Minimum LSP Bandwidth is encoded in a 4 octets field in the IEEE 257 floating point format. The units are bytes (not bits!) per second. 258 The indication whether the interface supports Standard or Arbitrary 259 SONET/SDH is encoded as 1 octet. The value of this octet is 0 if the 260 interface supports Standard SONET/SDH, and 1 if the interface 261 supports Arbitrary SONET/SDH. 263 When the Switching Capability field is LSC, there is no Switching 264 Capability specific information field present. 266 To support interfaces that have more than one Interface Switching 267 Capability Descriptor (see Section "Interface Switching Capability 268 Descriptor" of [GMPLS-ROUTING]) the Interface Switching Capability 269 Descriptor sub-TLV MAY occur more than once within the extended IS 270 reachability TLV. 272 3.4. Shared Risk Link Group TLV 274 The SRLG TLV (of type 138 TBD) contains a data structure consisting 275 of: 277 6 octets of System ID 278 1 octet of Pseudonode Number 279 1 octet Flag 280 4 octets of IPv4 interface address or 4 octets of a Link Local 281 Identifier 282 4 octets of IPv4 neighbor address or 4 octets of a Link Remote 283 Identifier 284 (variable) list of SRLG values, where each element in the list has 4 285 octets. 287 The following illustrates encoding of the Value field of the SRLG 288 TLV. 290 0 1 2 3 291 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 1 292 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 293 | System ID | 294 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 295 | System ID (cont.) | Pseudonode num| Flags | 296 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 297 | IPv4 interface address/Link Local Identifier | 298 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 299 | IPv4 neighbors address/Link Remote Identifier | 300 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 301 | Shared Risk Link Group Value | 302 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 303 | ............ | 304 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 305 | Shared Risk Link Group Value | 306 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 308 The neighbor is identified by its System Id (6-octets), plus one 309 octet to indicate the pseudonode number if the neighbor is on a LAN 310 interface. 312 The Least Significant Bit of the Flag octet indicates whether the 313 interface is numbered (set to 1), or unnumbered (set to 0). All 314 other bits are reserved and should be set to 0. 316 The length of this TLV is 16 + 4 * (number of SRLG values). 318 This TLV carries the Shared Risk Link Group information (see Section 319 "Shared Risk Link Group Information" of [GMPLS-ROUTING]). 321 The SRLG TLV MAY occur more than once within the IS-IS Link State 322 Protocol Data Units. 324 3.5. Link Identifier for Unnumbered Interfaces 326 Link Identifiers are exchanged in the Extended Local Circuit ID field 327 of the "Point-to-Point Three-Way Adjacency" IS-IS Option type 328 [ISIS-3way]. 330 4. Implications on Graceful Restart 332 The restarting node SHOULD follow the ISIS restart procedures [ISIS- 333 RESTART], and the RSVP-TE restart procedures [GMPLS-RSVP]. 335 When the restarting node is going to originate its IS-IS Link State 336 Protocol data units for TE links, these Link State Protocol data 337 units SHOULD be originated with 0 unreserved bandwidth, Traffic 338 Engineering Default metric set to 0xffffff, and if the link has LSC 339 or FSC as its Switching Capability then also with 0 as Max LSP 340 Bandwidth, until the node is able to determine the amount of 341 unreserved resources taking into account the resources reserved by 342 the already established LSPs that have been preserved across the 343 restart. Once the restarting node determines the amount of unreserved 344 resources, taking into account the resources reserved by the already 345 established LSPs that have been preserved across the restart, the 346 node SHOULD advertise these resources in its Link State Protocol data 347 units. 349 In addition in the case of a planned restart prior to restarting, the 350 restarting node SHOULD originate the IS-IS Link State Protocol data 351 units for TE links with 0 as unreserved bandwidth, and if the link 352 has LSC or FSC as its Switching Capability then also with 0 as Max 353 LSP Bandwidth. This would discourage new LSP establishment through 354 the restarting router. 356 Neighbors of the restarting node SHOULD continue advertise the actual 357 unreserved bandwidth on the TE links from the neighbors to that node. 359 5. Normative References 361 [GMPLS-ROUTING] Kompella, K., and Rekhter, Y. (Editors), "Routing 362 Extensions in Support of Generalized MPLS", (work in progress) 364 [GMPLS-RSVP] Berger, L. (Editors), "Generalized MPLS Signaling - 365 RSVP-TE Extensions", (work in progress) 367 [GMPLS-SIG] Berger, L. (Editor), "Generalized MPLS - Signaling 368 Functional Description", (work in progress) 370 [ISIS-3way] Katz, D., and Saluja, R., "Three-Way Handshake for IS-IS 371 Point-to-Point Adjacencies", (work in progress) 373 [ISIS-RESTART] Shand, M., "Restart signaling for ISIS", (work in 374 progress) 376 [ISIS-TE] Smit, H., Li, T., "IS-IS Extensions for Traffic 377 Engineering", (work in progress) 379 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 380 Requirement Levels", BCP 14, RFC 2119, March 1997. 382 6. Security Considerations 384 The extensions proposed in this document do not raise any new 385 security concerns. 387 7. Acknowledgements 389 The authors would like to thank Jim Gibson, Suresh Katukam, Jonathan 390 Lang and Quaizar Vohra for their comments on the draft. 392 8. Contributors 394 Ayan Banerjee 395 Calient Networks 396 5853 Rue Ferrari 397 San Jose, CA 95138 398 Phone: +1.408.972.3645 399 Email: abanerjee@calient.net 401 John Drake 402 Calient Networks 403 5853 Rue Ferrari 404 San Jose, CA 95138 405 Phone: (408) 972-3720 406 Email: jdrake@calient.net 408 Greg Bernstein 409 Ciena Corporation 410 10480 Ridgeview Court 411 Cupertino, CA 94014 412 Phone: (408) 366-4713 413 Email: greg@ciena.com 414 Don Fedyk 415 Nortel Networks Corp. 416 600 Technology Park Drive 417 Billerica, MA 01821 418 Phone: +1-978-288-4506 419 Email: dwfedyk@nortelnetworks.com 421 Eric Mannie 422 Independent Consultant 423 E-mail: eric_mannie@hotmail.com 425 Debanjan Saha 426 Tellium Optical Systems 427 2 Crescent Place 428 P.O. Box 901 429 Ocean Port, NJ 07757 430 Phone: (732) 923-4264 431 Email: dsaha@tellium.com 433 Vishal Sharma 434 Metanoia, Inc. 435 335 Elan Village Lane, Unit 203 436 San Jose, CA 95134-2539 437 Phone: +1 408-943-1794 438 Email: v.sharma@ieee.org 440 9. Authors' Information 442 Kireeti Kompella 443 Juniper Networks, Inc. 444 1194 N. Mathilda Ave 445 Sunnyvale, CA 94089 446 Email: kireeti@juniper.net 448 Yakov Rekhter 449 Juniper Networks, Inc. 450 1194 N. Mathilda Ave 451 Sunnyvale, CA 94089 452 Email: yakov@juniper.net 453 10. Intellectual Property Rights Notices 455 The IETF takes no position regarding the validity or scope of any 456 intellectual property or other rights that might be claimed to 457 pertain to the implementation or use of the technology described in 458 this document or the extent to which any license under such rights 459 might or might not be available; neither does it represent that it 460 has made any effort to identify any such rights. 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