idnits 2.17.1 draft-ietf-ccamp-mpls-tp-rsvpte-ext-associated-lsp-08.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 : ---------------------------------------------------------------------------- ** There is 1 instance of lines with control characters in the document. Miscellaneous warnings: ---------------------------------------------------------------------------- == The copyright year in the IETF Trust and authors Copyright Line does not match the current year == The expression 'MAY NOT', while looking like RFC 2119 requirements text, is not defined in RFC 2119, and should not be used. Consider using 'MUST NOT' instead (if that is what you mean). Found 'MAY NOT' in this paragraph: For the single sided provisioning where the REVERSE_LSP object is not signaled, the teardown of the initiating LSP SHOULD trigger the teardown of the reverse LSP, however, teardown of the reverse LSP MAY NOT trigger the teardown of the initiating LSP (which may depend on the local policy). == 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 'SHOULD not' in this paragraph: For the double sided provisioning, the teardown of one unidirectional LSP SHOULD not trigger teardown of the reverse LSP. -- The document date (March 2, 2014) is 3707 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) == Missing Reference: 'RFC5420' is mentioned on line 590, but not defined Summary: 1 error (**), 0 flaws (~~), 4 warnings (==), 1 comment (--). Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 2 CCAMP Working Group F. Zhang, Ed. 3 Internet-Draft ZTE 4 Intended status: Standards Track R. Jing 5 Expires: September 3, 2014 China Telecom 6 R. Gandhi, Ed. 7 Cisco Systems 8 March 2, 2014 10 RSVP-TE Extensions for Associated Bidirectional LSPs 11 draft-ietf-ccamp-mpls-tp-rsvpte-ext-associated-lsp-08 13 Abstract 15 This document describes Resource reSerVation Protocol (RSVP) 16 extensions to bind two point-to-point unidirectional Label Switched 17 Paths (LSPs) into an associated bidirectional LSP. The association is 18 achieved by defining the new Association Types in (Extended) 19 ASSOCIATION object. In addition, RSVP extensions allow asymmetric 20 upstream and downstream bandwidths for the bidirectional LSP. 22 Status of this Memo 24 This Internet-Draft is submitted in full conformance with the 25 provisions of BCP 78 and BCP 79. 27 Internet-Drafts are working documents of the Internet Engineering 28 Task Force (IETF). Note that other groups may also distribute 29 working documents as Internet-Drafts. The list of current Internet- 30 Drafts is at http://datatracker.ietf.org/drafts/current/. 32 Internet-Drafts are draft documents valid for a maximum of six months 33 and may be updated, replaced, or obsoleted by other documents at any 34 time. It is inappropriate to use Internet-Drafts as reference 35 material or to cite them other than as "work in progress." 37 Copyright Notice 39 Copyright (c) 2014 IETF Trust and the persons identified as the 40 document authors. All rights reserved. 42 This document is subject to BCP 78 and the IETF Trust's Legal 43 Provisions Relating to IETF Documents 44 (http://trustee.ietf.org/license-info) in effect on the date of 45 publication of this document. Please review these documents 46 carefully, as they describe your rights and restrictions with respect 47 to this document. Code Components extracted from this document must 48 include Simplified BSD License text as described in Section 4.e of 49 the Trust Legal Provisions and are provided without warranty as 50 described in the Simplified BSD License. 52 Table of Contents 54 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 55 2. Conventions used in this document . . . . . . . . . . . . . . 4 56 3. Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 57 3.1. Provisioning Model Overview . . . . . . . . . . . . . . . 4 58 3.1.1. Single Sided Provisioning . . . . . . . . . . . . . . 4 59 3.1.2. Double Sided Provisioning . . . . . . . . . . . . . . 4 60 3.2. Association Signaling Overview . . . . . . . . . . . . . . 5 61 3.2.1. Single Sided Provisioning . . . . . . . . . . . . . . 5 62 3.2.2. Double Sided Provisioning . . . . . . . . . . . . . . 6 63 3.3. Asymmetric Bandwidth Signaling Overview . . . . . . . . . 6 64 3.3.1. Single Sided Provisioning . . . . . . . . . . . . . . 6 65 3.3.2. Double Sided Provisioning . . . . . . . . . . . . . . 6 66 3.4. Recovery LSP Overview . . . . . . . . . . . . . . . . . . 7 67 3.4.1. Single Sided Provisioning . . . . . . . . . . . . . . 7 68 3.4.2. Double Sided Provisioning . . . . . . . . . . . . . . 7 69 3.5. Provisioning For Mesh-Groups . . . . . . . . . . . . . . . 7 70 4. Processing Rules . . . . . . . . . . . . . . . . . . . . . . . 7 71 4.1. ASSOCIATION Object . . . . . . . . . . . . . . . . . . . . 8 72 4.2. Extended ASSOCIATION Object . . . . . . . . . . . . . . . 8 73 4.3. Rules For ASSOCIATION Object . . . . . . . . . . . . . . . 9 74 4.3.1. Teardown of Associated LSPs . . . . . . . . . . . . . 10 75 4.3.2. Compatibility For ASSOCIATION Object . . . . . . . . . 10 76 4.4. Rules For REVERSE_LSP Object . . . . . . . . . . . . . . . 10 77 4.4.1. Teardown of Associated LSPs . . . . . . . . . . . . . 11 78 4.4.2. Compatibility For REVERSE_LSP Object . . . . . . . . . 11 79 5. Message and Object Definitions . . . . . . . . . . . . . . . . 12 80 5.1. RSVP Message Formats . . . . . . . . . . . . . . . . . . . 12 81 5.2. ASSOCIATION Object Definition . . . . . . . . . . . . . . 12 82 5.3. REVERSE_LSP Object Definition . . . . . . . . . . . . . . 12 83 5.3.1. REVERSE_LSP Object Format . . . . . . . . . . . . . . 12 84 5.3.2. REVERSE_LSP Subobjects . . . . . . . . . . . . . . . . 13 85 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 13 86 6.1. Association Types . . . . . . . . . . . . . . . . . . . . 13 87 6.2. REVERSE_LSP Object . . . . . . . . . . . . . . . . . . . . 14 88 7. Security Considerations . . . . . . . . . . . . . . . . . . . 14 89 8. Acknowledgement . . . . . . . . . . . . . . . . . . . . . . . 14 90 9. References . . . . . . . . . . . . . . . . . . . . . . . . . . 15 91 9.1. Normative References . . . . . . . . . . . . . . . . . . . 15 92 9.2. Informative References . . . . . . . . . . . . . . . . . . 15 93 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 16 95 1. Introduction 97 The MPLS Transport Profile (MPLS-TP) requirements document [RFC5654] 98 specifies that MPLS-TP MUST support associated bidirectional point- 99 to-point Label Switched Paths (LSPs). These requirements are given in 100 Section 2.1 (General Requirements), and are repeated below: 102 7. MPLS-TP MUST support associated bidirectional point-to-point 103 LSPs. 105 11. The end points of an associated bidirectional LSP MUST be aware 106 of the pairing relationship of the forward and reverse LSPs used to 107 support the bidirectional service. 109 12. Nodes on the LSP of an associated bidirectional LSP where both 110 the forward and backward directions transit the same node in the same 111 (sub)layer as the LSP SHOULD be aware of the pairing relationship of 112 the forward and the backward directions of the LSP. 114 14. MPLS-TP MUST support bidirectional LSPs with asymmetric 115 bandwidth requirements, i.e., the amount of reserved bandwidth 116 differs between the forward and backward directions. 118 50. The MPLS-TP control plane MUST support establishing associated 119 bidirectional P2P LSP including configuration of protection functions 120 and any associated maintenance functions. 122 The above requirements are also repeated in [RFC6373]. 124 Furthermore, an associated bidirectional LSP is also useful for 125 protection switching for Operations, Administrations and Maintenance 126 (OAM) messages that require a return path. 128 A variety of applications, such as Internet services and the return 129 paths of OAM messages, exist and which may have different upstream 130 and downstream bandwidth requirements. [RFC5654] specifies an 131 asymmetric bandwidth requirement in Section 2.1 (General 132 Requirements), and is repeated below: 134 14. MPLS-TP MUST support bidirectional LSPs with asymmetric 135 bandwidth requirements, i.e., the amount of reserved bandwidth 136 differs between the forward and backward directions. 138 The approach for supporting asymmetric bandwidth co-routed 139 bidirectional LSPs is defined in [RFC6387]. 141 The method of association and the corresponding Resource reSerVation 142 Protocol (RSVP) ASSOCIATION object are defined in [RFC4872], 144 [RFC4873] and [RFC6689]. In that context, the ASSOCIATION object is 145 used to associate a recovery LSP with the LSP it is protecting. This 146 object also has broader applicability as a mechanism to associate 147 RSVP states. [RFC6780] defines an Extended ASSOCIATION object that 148 can be more generally applied for this purpose. 150 This document specifies mechanisms for binding two reverse 151 unidirectional LSPs into an associated bidirectional LSP. The 152 association is achieved by defining new Association Types in the 153 (Extended) ASSOCIATION object. RSVP extensions allow asymmetric 154 upstream and downstream bandwidths for the bidirectional LSP. 156 2. Conventions used in this document 158 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 159 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this 160 document are to be interpreted as described in [RFC2119]. 162 3. Overview 164 3.1. Provisioning Model Overview 166 This section provides an overview of the models for provisioning 167 bidirectional LSPs. 169 The associated bidirectional LSP's forward and reverse unidirectional 170 LSPs are established, monitored, and protected independently as 171 specified by [RFC5654]. Configuration information regarding the LSPs 172 can be provided at one or both endpoints of the associated 173 bidirectional LSP. Depending on the method chosen, there are two 174 models of creating an associated bidirectional LSP; single sided 175 provisioning, and double sided provisioning. 177 3.1.1. Single Sided Provisioning 179 For the single sided provisioning, the TE tunnel is configured only 180 on one side. An LSP for this tunnel is initiated by the initiating 181 endpoint with the (Extended) ASSOCIATION object inserted in the Path 182 message. The other endpoint then creates the corresponding reverse TE 183 tunnel and signals the reverse LSP in response to this. 185 3.1.2. Double Sided Provisioning 187 For the double sided provisioning, two unidirectional TE tunnels are 188 configured independently on both sides. The LSPs for the tunnels are 189 signaled with (Extended) ASSOCIATION objects inserted in the Path 190 message by both sides to indicate that the two LSPs are to be 191 associated to form a bidirectional LSP. 193 3.2. Association Signaling Overview 195 This section provides an overview of the association signaling 196 methods for the bidirectional LSPs. 198 Three scenarios exist for binding two unidirectional LSPs together to 199 form an associated bidirectional LSP. These are: 1) Neither 200 unidirectional LSP exists, and both must be established. 2) Both 201 unidirectional LSPs exist, but the association must be established. 202 3) One LSP exists, but the reverse associated LSP must be 203 established. 205 In each of the situations described above, both provisioning models 206 are applicable. 208 Path Computation Element (PCE)-based approaches [RFC4655], may be 209 used for path computation of an associated bidirectional LSP. 210 However, these approaches are outside the scope of this document. 212 Consider the topology described in Figure 1 (an example of associated 213 bidirectional LSP). LSP1 from A to B, takes the path A,D,B and LSP2 214 from B to A takes the path B,D,C,A. These two LSPs, once established 215 and associated, form an associated bidirectional LSP between node A 216 and node B. 218 LSP1 --> 219 A-------D-------B 220 \ / <-- LSP2 221 \ / 222 \ / 223 C 225 Figure 1: An example of associated bidirectional LSP 227 3.2.1. Single Sided Provisioning 229 For the single sided provisioning model, creation of reverse LSP1 is 230 triggered by LSP2 or creation of reverse LSP2 is triggered by LSP1. 231 When creation of reverse LSP2 is triggered by LSP1, LSP1 is 232 provisioned first (or refreshed if LSP1 already exists) at node A. 233 LSP1 is then signaled with an (Extended) ASSOCIATION object inserted 234 in the Path message, in which the Association Type indicating single 235 sided provisioning. Upon receiving this Path message for LSP1, node B 236 establishes reverse LSP2. The (Extended) ASSOCIATION object inserted 237 in LSP2's Path message is the same as that received in LSP1's Path 238 message. 240 A similar procedure is used if LSP2 is provisioned first at node B 241 and the creation of reverse LSP1 is triggered by LSP2. In both cases, 242 the two unidirectional LSPs are bound together to form an associated 243 bidirectional LSP based on identical (Extended) ASSOCIATION objects 244 in the two LSPs' Path messages. 246 3.2.2. Double Sided Provisioning 248 For the double sided provisioning model, both LSP1 and LSP2 are 249 signaled independently with (Extended) ASSOCIATION object inserted in 250 the Path message, in which the Association Type indicating double 251 sided provisioning. In this case, the two unidirectional LSPs are 252 bound together to form an associated bidirectional LSP based on 253 identical (Extended) ASSOCIATION objects in the two LSPs' Path 254 messages. 256 3.3. Asymmetric Bandwidth Signaling Overview 258 This section provides an overview of the methods for signaling 259 asymmetric upstream and downstream bandwidths for the associated 260 bidirectional LSPs. 262 3.3.1. Single Sided Provisioning 264 New REVERSE_LSP object applicable to the single sided provisioning 265 model is defined in this document, in Section 5.3. When the single 266 sided provisioning model is used, the existing SENDER_TSPEC object is 267 added in the REVERSE_LSP object as a subobject in the initiating 268 LSP's Path message to specify the reverse LSP's traffic parameters. 269 As described in Section 5.3, addition of the REVERSE_LSP object also 270 allows the initiating node to control the reverse LSP. 272 Consider again the topology described in Figure 1, where the creation 273 of reverse LSP2 is triggered by LSP1. Node A signals LSP1 with the 274 (Extended) ASSOCIATION object with Association Type indicating single 275 sided provisioning and inserts SENDER_TSPEC subobject in the 276 REVERSE_LSP object in the Path message. Node B then establishes the 277 LSP2 in the reverse direction using the asymmetric bandwidth thus 278 specified by LSP1 and allows node A to control the reverse LSP2. 280 3.3.2. Double Sided Provisioning 282 When the double sided provisioning model is used, the two 283 unidirectional LSPs are established with asymmetric bandwidths 284 independently. However, these LSPs are associated purely based on the 285 identical contents of their (Extended) ASSOCIATION objects. 287 3.4. Recovery LSP Overview 289 Consider again the topology described in Figure 1, where LSP1 and 290 LSP2 form an associated bidirectional LSP. Under a recovery scenario, 291 a third LSP (LSP3) may be used to protect LSP1 on node A. LSP3 may be 292 established before or after the failure occurs. LSP3 in this case 293 belongs to the same TE tunnel as LSP1 on node A. 295 When node A detects that LSP1 has failed or needs to be reoptimized, 296 LSP3 is initialized or refreshed with the (Extended) ASSOCIATION 297 object (including the Association Type) inherited from LSP1's Path 298 message. If LSP3 is the protecting LSP [RFC4872], the PROTECTION 299 object [RFC4872] is also inherited from LSP1. In any case, LSP2 and 300 LSP3 are associated to form an associated bidirectional LSP based on 301 the identical (Extended) ASSOCIATION objects in their Path messages. 303 3.4.1. Single Sided Provisioning 305 When the single sided provisioning model is used, recovery LSP3 on 306 node A triggers the creation of reverse recovery LSP4 on node B as 307 described in Section 3.2.1 of this document. However, node A and node 308 B perform LSP recovery actions independently [RFC5654]. 310 3.4.2. Double Sided Provisioning 312 When the double sided provisioning model is used, recovery LSP3 on 313 node A may or may not have associated reverse recovery LSP4 on node 314 B. In any case, node A and node B perform LSP recovery actions 315 independently [RFC5654]. 317 3.5. Provisioning For Mesh-Groups 319 TE mesh-groups are defined in [RFC4972]. In order to enable 320 unambiguous association of the mesh-group's bidirectional LSPs, the 321 information carried in the (Extended) ASSOCIATION object, 322 specifically the contents of the Association Source and Identifier 323 fields are provisioned for the mesh-groups using the models specified 324 in Section 3.1.1 and 3.1.2 of this document, namely, single sided and 325 double sided provisioning. 327 4. Processing Rules 329 In general, the processing rules for the ASSOCIATION object are as 330 specified in [RFC4872] and Extended ASSOCIATION object are specified 331 in [RFC6780]. Following sections describe the rules for processing 332 (Extended) ASSOCIATION and REVERSE_LSP objects for associated 333 bidirectional LSPs. 335 4.1. ASSOCIATION Object 337 The ASSOCIATION object is populated using the rules defined below for 338 associating two reverse unidirectional LSPs to form a bidirectional 339 LSP. 341 Association Types: 343 In order to bind two reverse unidirectional LSPs to be an 344 associated bidirectional LSP, the Association Type MUST be set to 345 indicate either single sided or double sided LSPs. 347 The new Association Types are defined as follows: 349 Value Type 351 ----- ----- 352 4 (TBD) Double Sided Associated Bidirectional LSPs (D) 353 5 (TBD) Single Sided Associated Bidirectional LSPs (A) 355 Association ID: 357 For both single sided and double sided provisioning, Association 358 ID MUST be set to a value assigned by the node that originates the 359 association for the bidirectional LSP. 361 Association Source: 363 For double sided provisioning, Association Source MUST be set to 364 an address selected by the node that originates the association 365 for the bidirectional LSP (which may be a management entity.) 367 For single sided provisioning, Association Source MUST be set to 368 an address assigned to the node that originates the LSP. 370 4.2. Extended ASSOCIATION Object 372 The Extended ASSOCIATION object is populated using the rules defined 373 below for associating two reverse unidirectional LSPs to form a 374 bidirectional LSP. 376 The Association Type, Association ID and Association Source MUST be 377 set as defined for the ASSOCIATION object in Section 4.1. 379 Global Association Source: 381 For both single sided and double sided provisioning, Global 382 Association Source, when used, MUST be set to the Global_ID 383 [RFC6370] of the node that originates the association for the 384 bidirectional LSP. 386 Extended Association ID: 388 For both single sided and double sided provisioning, Extended 389 Association ID, when used, MUST be set to a value selected by the 390 node that originates the association for the bidirectional LSP. 392 4.3. Rules For ASSOCIATION Object 394 The ASSOCIATION object is inserted in the Path message of the LSP 395 using the rules defined in this document for associating two reverse 396 unidirectional LSPs to form an associated bidirectional LSP. 398 For associating two unidirectional LSPs to form a bidirectional LSP, 399 if either Global Association Source or Extended Association Address 400 is required, then an Extended ASSOCIATION object [RFC6780] is 401 inserted in the Path message of the LSP instead of the ASSOCIATION 402 object. 404 Association Type in the (Extended) ASSOCIATION object MUST be set to 405 the "Single Sided Associated Bidirectional LSPs" or "Double Sided 406 Associated Bidirectional LSPs" based on the single sided or double 407 sided provisioning model used for the LSPs. ASSOCIATION or Extended 408 ASSOCIATION objects with both single sided and double sided 409 Association Types MUST NOT be added in the same Path message. 411 As described in [RFC6780], association of the LSPs is based on 412 matching ASSOCIATION objects in Path or Resv. Upstream initialized 413 association is represented in (Extended) ASSOCIATION object carried 414 in the Path message and downstream initialized association is 415 represented in (Extended) ASSOCIATION object carried in the Resv 416 message. The new Association Types defined in this document are only 417 used in upstream initialized association. Thus they can appear in the 418 (Extended) ASSOCIATION object in Path message only. 420 The procedures associated with the processing of the (Extended) 421 ASSOCIATION objects are discussed in [RFC6780]. [RFC6780] specifies 422 that in the absence of Association Type-specific rule for identifying 423 association, the included (Extended) ASSOCIATION objects in the LSPs 424 MUST be identical in order for an association to be formed. This 425 document adds no specific rules for the new Association Types 426 defined, and the determination of LSP association therefore proceeds 427 as specified in [RFC6780]. 429 LSP recovery as defined in [RFC4872] and [RFC4873] is not impacted by 430 this document. The recovery mechanisms defined in [RFC4872] and 431 [RFC4873] rely on the use of ASSOCIATION objects, but use a different 432 value for Association Type; multiple ASSOCIATION objects MAY exist in 433 the LSP Path message and MAY coexist with the procedures defined in 434 this document. 436 As specified in [RFC4872], an endpoint node that does not support the 437 new Association Types defined in this document MUST return a PathErr 438 message with the error code "LSP Admission Failure" (value 01 as 439 defined in [RFC2205]) and the sub-code "Bad Association Type" (value 440 5 as defined in [RFC4872]). 442 4.3.1. Teardown of Associated LSPs 444 Associated bidirectional LSP teardown follows the standard procedures 445 defined in [RFC3209] and [RFC3473] either without or with the 446 administrative status. Note that teardown procedures of the 447 unidirectional LSPs forming an associated bidirectional LSP are 448 independent of each other, so it is possible that while one LSP 449 follows graceful teardown with administrative status, the reverse LSP 450 is torn down without administrative status (using 451 PathTear/ResvTear/PathErr with state removal). 453 For the single sided provisioning where the REVERSE_LSP object is not 454 signaled, the teardown of the initiating LSP SHOULD trigger the 455 teardown of the reverse LSP, however, teardown of the reverse LSP MAY 456 NOT trigger the teardown of the initiating LSP (which may depend on 457 the local policy). 459 For the double sided provisioning, the teardown of one unidirectional 460 LSP SHOULD not trigger teardown of the reverse LSP. 462 4.3.2. Compatibility For ASSOCIATION Object 464 The ASSOCIATION object has been defined in [RFC4872] and the Extended 465 ASSOCIATION object has been defined in [RFC6780], both with class 466 numbers in the form 11bbbbbb, which ensures compatibility with 467 non-supporting nodes. Per [RFC2205], such nodes will ignore the 468 object but forward it without modification. 470 Operators wishing to use a function supported by a particular 471 association type SHOULD ensure that the type is supported on any node 472 that is expected to act on the association [RFC6780]. 474 4.4. Rules For REVERSE_LSP Object 476 A node initiating a Path message containing an ASSOCIATION or 477 Extended ASSOCIATION object with the Association Type set to "Single 478 Sided Associated Bidirectional LSPs" MAY include a REVERSE_LSP object 479 in the Path message of the LSP when it wishes to control the reverse 480 LSP on the other endpoint node and to specify the reverse LSP's 481 traffic parameters. 483 The REVERSE_LSP subobject MAY contain any of the specified subobjects 484 which the initiating node desires to have included in the Path 485 message for the associated reverse LSP. A REVERSE_LSP object MUST 486 contain at least one subobject. 488 A node receiving a valid Path message containing a REVERSE_LSP object 489 that is not the endpoint node for the LSP being signaled MUST forward 490 the REVERSE_LSP object unchanged in the outgoing Path message. 492 The endpoint node upon receiving a Path message containing a 493 REVERSE_LSP object triggers to establish the reverse LSP according to 494 the received parameters in the REVERSE_LSP object. The receiver 495 endpoint node MUST convert the subobjects of the REVERSE_LSP object 496 into the corresponding objects to be carried in the reverse LSP's 497 Path message. 499 A Path message that does not contain an ASSOCIATION or Extended 500 ASSOCIATION object with the Association Type set to "Single Sided 501 Associated Bidirectional LSPs" MUST NOT contain a REVERSE_LSP object. 503 4.4.1. Teardown of Associated LSPs 505 If initiating node controlling the reverse LSP using the procedure 506 defined in this document, wishes to tear down the associated 507 bidirectional LSP, the initiating node sends a PathTear message to 508 the other endpoint, the other endpoint MUST trigger to tear down the 509 reverse associated LSP. 511 4.4.2. Compatibility For REVERSE_LSP Object 513 The REVERSE_LSP object is defined with class numbers in the form 514 11bbbbbb, which ensures compatibility with non-supporting nodes. Per 515 [RFC2205], such nodes will ignore the object but forward it without 516 modification. 518 Per [RFC2205], an endpoint node that does not support the REVERSE_LSP 519 C-Type MAY generate an "Unknown object C-Type" error. This error will 520 propagate to the initiating node for standard error processing. 522 5. Message and Object Definitions 524 5.1. RSVP Message Formats 526 This section presents the RSVP message-related formats as modified by 527 this document. Unmodified RSVP message formats are not listed. 529 The format of a Path message is as follows: 531 ::= [ ] 532 [ [ | ] ... ] 533 [ ] 534 535 536 [ ] 537 538 [ ] 539 [ ... ] 540 [ ] 541 [ ... ] 542 [ ] 543 [ ... ] 544 [ ... ] 546 548 The format of the is not modified by this 549 document. 551 5.2. ASSOCIATION Object Definition 553 The ASSOCIATION object is defined in [RFC4872]. The Extended 554 ASSOCIATION object is defined in [RFC6780]. Other than the two new 555 Association Types defined in this document, the (Extended) 556 ASSOCIATION object definition is not modified by this document. 558 5.3. REVERSE_LSP Object Definition 560 5.3.1. REVERSE_LSP Object Format 562 The information of the reverse LSP is specified via the REVERSE_LSP 563 object. This is an optional object carried in a Path message with 564 class numbers in the form 11bbbbbb and has the following format: 566 Class = TBD (of the form 11bbbbbb), C_Type = (TBD) 567 0 1 2 3 568 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 1 569 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 570 | | 571 // (Subobjects) // 572 | | 573 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 575 5.3.2. REVERSE_LSP Subobjects 577 The contents of a REVERSE_LSP object is a variable length series of 578 subobjects. The subobjects permitted in the REVERSE_LSP object are 579 previously defined as Path message subobjects, and have the same 580 format and order in the REVERSE_LSP object. 582 Examples of the Path message subobjects carried in the REVERSE_LSP 583 object are (but not limited to): 585 - SENDER_TSPEC [RFC2205] 586 - EXPLICIT_ROUTE object (ERO) [RFC3209] 587 - SESSION_ATTRIBUTE object [RFC3209] 588 - ADMIN_STATUS object [RFC3473] 589 - LSP_ATTRIBUTES object [RFC5420] 590 - LSP_REQUIRED_ATTRIBUTES object [RFC5420] 591 - PROTECTION object [RFC3473] [RFC4872] 593 6. IANA Considerations 595 IANA is requested to administer assignment of new values for 596 namespace defined in this document and summarized in this section. 598 6.1. Association Types 600 New Association Types for ASSOCIATION and Extended ASSOCIATION 601 objects are defined in this document as follows: 603 Value Type 604 ----- ----- 605 4 (TBD) Double Sided Associated Bidirectional LSPs (D) 606 5 (TBD) Single Sided Associated Bidirectional LSPs (A) 608 6.2. REVERSE_LSP Object 610 A new class type for REVERSE_LSP has been requested in the 11bbbbbb 611 range (TBD) with the following definition: 613 Class Types or C-types (TBD), Value (TBD): REVERSE_LSP Object 615 There are no other IANA considerations introduced by this document. 617 7. Security Considerations 619 This document introduces two new Association Types, however, no new 620 security issues relating to the (Extended) ASSOCIATION object are 621 introduced. 623 The procedures defined in this document result in an increased state 624 information carried in signaling messages. The presence of the 625 REVERSE_LSP object necessarily provides more information about the 626 LSPs. Thus, in the event of the interception of a signaling message, 627 slightly more information about the state of the network could be 628 deduced than was previously the case. This is judged to be a very 629 minor security risk as this information is already available via 630 routing. 632 Otherwise, this document introduces no additional security 633 considerations. For a general discussion on MPLS and GMPLS related 634 security issues, see the MPLS/GMPLS security framework [RFC5920]. 636 8. Acknowledgement 638 The authors would like to thank Lou Berger and George Swallow for 639 their great guidance in this work, Jie Dong for the discussion of 640 recovery, Lamberto Sterling for his valuable comments on the section 641 of asymmetric bandwidths, Daniel King for the review of the document, 642 Attila Takacs for the discussion of the provisioning model. At the 643 same time, the authors would also like to acknowledge the 644 contributions of Bo Wu, Xihua Fu, Lizhong Jin for the initial 645 discussions, and Wenjuan He for the prototype implementation. The 646 authors would also like to thank Siva Sivabalan, Eric Osborne and 647 Robert Sawaya for the discussions on the ASSOCIATION object. The 648 authors would like to thank Matt Hartley for providing useful 649 suggestions on the document. 651 9. References 653 9.1. Normative References 655 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 656 Requirement Levels", BCP 14, RFC 2119, March 1997. 658 [RFC2205] Braden, B., Zhang, L., Berson, S., Herzog, S., and S. 659 Jamin, "Resource ReSerVation Protocol (RSVP) -- Version 1 660 Functional Specification", RFC 2205, September 1997. 662 [RFC3209] Awduche, D., Berger, L., Gan, D., Li, T., Srinivasan, V., 663 and G. Swallow, "RSVP-TE: Extensions to RSVP for LSP 664 Tunnels", RFC 3209, December 2001. 666 [RFC4872] Lang, J., Rekhter, Y., and D. Papadimitriou, "RSVP-TE 667 Extensions in Support of End-to-End Generalized Multi- 668 Protocol Label Switching (GMPLS) Recovery", RFC 4872, May 669 2007. 671 [RFC4873] Berger, L., Bryskin, I., Papadimitriou, D., and A. Farrel, 672 "GMPLS Segment Recovery", RFC 4873, May 2007. 674 [RFC6780] Berger, L., Le Faucheur, F., and A. Narayanan, "RSVP 675 Association Object Extensions", RFC 6780, October 2012. 677 9.2. Informative References 679 [RFC3473] Berger, L., "Generalized Multi-Protocol Label Switching 680 (GMPLS) Signaling Resource ReserVation Protocol-Traffic 681 Engineering (RSVP-TE) Extensions", RFC 3473, January 2003. 683 [RFC4655] Farrel, A., Vasseur, J., and J. Ash, "A Path Computation 684 Element (PCE)-Based Architecture", RFC 4655, August 2006. 686 [RFC4972] Vasseur, JP., Leroux, JL., Yasukawa, S., Previdi, S., 687 Psenak, P., Mabbey, P., "Routing Extensions for Discovery 688 of Multiprotocol (MPLS) Label Switch Router (LSR) Traffic 689 Engineering (TE) Mesh Membership", RFC 4972, July 2007. 691 [RFC5654] Niven-Jenkins, B., Brungard, D., Betts, M., Sprecher, N., 692 and S. Ueno, "Requirements of an MPLS Transport Profile", 693 RFC 5654, September 2009. 695 [RFC5920] Fang, L., "Security Framework for MPLS and GMPLS 696 Networks", RFC 5920, July 2010. 698 [RFC6370] Bocci, M., Swallow, G., and E. Gray, "MPLS Transport 699 Profile (MPLS-TP) Identifiers", RFC 6370, September 2011. 701 [RFC6373] Andersson, L., Berger, L., Fang, L., Bitar, N., and E. 702 Gray, "MPLS Transport Profile (MPLS-TP) Control Plane 703 Framework", RFC 6373, September 2011. 705 [RFC6387] Takacs, A., Berger, L., Caviglia, D., Fedyk, D., and J. 706 Meuric, "GMPLS Asymmetric Bandwidth Bidirectional Label 707 Switched Paths (LSPs)", RFC 6387, September 2011. 709 [RFC6689] Berger, L., "Usage of The RSVP Association Object", RFC 710 6689, July 2012. 712 Authors' Addresses 714 Fei Zhang (editor) 715 ZTE 717 Email: zhang.fei3@zte.com.cn 719 Ruiquan Jing 720 China Telecom 722 Email: jingrq@ctbri.com.cn 724 Fan Yang 725 ZTE 727 Email: yang.fan240347@gmail.com 729 Weilian Jiang 730 ZTE 732 Email: jiang.weilian@gmail.com 734 Rakesh Gandhi (editor) 735 Cisco Systems 737 Email: rgandhi@cisco.com