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Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 2 PCE Working Group H. Ananthakrishnan 3 Internet-Draft Packet Design 4 Intended status: Standards Track S. Sivabalan 5 Expires: August 31, 2018 Cisco 6 C. Barth 7 R. Torvi 8 Juniper Networks 9 I. Minei 10 Google, Inc 11 E. Crabbe 12 Individual Contributor 13 D. Dhody 14 Huawei Technologies 15 February 27, 2018 17 PCEP Extensions for MPSL-TE LSP Path Protection with stateful PCE 18 draft-ananthakrishnan-pce-stateful-path-protection-05 20 Abstract 22 A stateful Path Computation Element (PCE) is capable of computing as 23 well as controlling via Path Computation Element Protocol (PCEP) 24 Multiprotocol Label Switching Traffic Engineering Label Switched 25 Paths (MPLS LSP). Furthermore, it is also possible for a stateful 26 PCE to create, maintain, and delete LSPs. This document describes 27 PCEP extension to associate two or more LSPs to provide end-to-end 28 path protection. 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 31, 2018. 47 Copyright Notice 49 Copyright (c) 2018 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 . . . . . . . . . . . . . . . . . . . . . . . . 3 65 1.1. Requirements Language . . . . . . . . . . . . . . . . . . 4 66 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 4 67 3. PCEP Extensions . . . . . . . . . . . . . . . . . . . . . . . 5 68 3.1. Path Protection Association Type . . . . . . . . . . . . 5 69 3.2. Path Protection Association TLV . . . . . . . . . . . . . 5 70 4. Operation . . . . . . . . . . . . . . . . . . . . . . . . . . 6 71 4.1. State Synchronization . . . . . . . . . . . . . . . . . . 6 72 4.2. PCC Initiated LSPs . . . . . . . . . . . . . . . . . . . 6 73 4.3. PCE Initiated LSPs . . . . . . . . . . . . . . . . . . . 7 74 4.4. Session Termination . . . . . . . . . . . . . . . . . . . 7 75 4.5. Error Handling . . . . . . . . . . . . . . . . . . . . . 7 76 5. Other considerations . . . . . . . . . . . . . . . . . . . . 8 77 6. IANA considerations . . . . . . . . . . . . . . . . . . . . . 8 78 6.1. Association Type . . . . . . . . . . . . . . . . . . . . 8 79 6.2. PPAG TLV . . . . . . . . . . . . . . . . . . . . . . . . 8 80 6.3. PCEP Errors . . . . . . . . . . . . . . . . . . . . . . . 9 81 7. Security Considerations . . . . . . . . . . . . . . . . . . . 10 82 8. Manageability Considerations . . . . . . . . . . . . . . . . 10 83 8.1. Control of Function and Policy . . . . . . . . . . . . . 10 84 8.2. Information and Data Models . . . . . . . . . . . . . . . 10 85 8.3. Liveness Detection and Monitoring . . . . . . . . . . . . 10 86 8.4. Verify Correct Operations . . . . . . . . . . . . . . . . 10 87 8.5. Requirements On Other Protocols . . . . . . . . . . . . . 10 88 8.6. Impact On Network Operations . . . . . . . . . . . . . . 11 89 9. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 11 90 10. References . . . . . . . . . . . . . . . . . . . . . . . . . 11 91 10.1. Normative References . . . . . . . . . . . . . . . . . . 11 92 10.2. Information References . . . . . . . . . . . . . . . . . 12 93 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 13 95 1. Introduction 97 [RFC5440] describes PCEP for communication between a Path Computation 98 Client (PCC) and a PCE or between one a pair of PCEs as per 99 [RFC4655]. A PCE computes paths for MPLS-TE LSPs based on various 100 constraints and optimization criteria. 102 Stateful pce [RFC8231] specifies a set of extensions to PCEP to 103 enable stateful control of paths such as MPLS TE LSPs between and 104 across PCEP sessions in compliance with [RFC4657]. It includes 105 mechanisms to effect LSP state synchronization between PCCs and PCEs, 106 delegation of control of LSPs to PCEs, and PCE control of timing and 107 sequence of path computations within and across PCEP sessions and 108 focuses on a model where LSPs are configured on the PCC and control 109 over them is delegated to the PCE. Furthermore, a mechanism to 110 dynamically instantiate LSPs on a PCC based on the requests from a 111 stateful PCE or a controller using stateful PCE, is specified in 112 [RFC8281]. 114 Path protection [RFC4427] refers to a paradigm in which the working 115 LSP is protected by one or more protection LSP(s). When the working 116 LSP fails, protection LSP(s) is/are activated. When the working LSPs 117 are computed and controlled by the PCE, there is benefit in a mode of 118 operation where protection LSPs are as well. 120 This document specifies a stateful PCEP extension to associate two or 121 more LSPs for the purpose of setting up path protection. The 122 proposed extension covers the following scenarios: 124 o A PCC initiates a protection LSP and retains the control of the 125 LSP. The PCC computes the path itself or makes a request for path 126 computation to a PCE. After the path setup, it reports the 127 information and state of the path to the PCE. This includes the 128 association group identifying the working and protection LSPs. 129 This is the passive stateful mode [RFC8051]. 131 o A PCC initiates a protection LSP and delegates the control of the 132 LSP to a stateful PCE. During delegation the association group 133 identifying the working and protection LSPs is included. The PCE 134 computes the path for the protection LSP and update the PCC with 135 the information about the path as long as it controls the LSP. 136 This is the active stateful mode [RFC8051]. 138 o A protection LSP could be initiated by a stateful PCE, which 139 retains the control of the LSP. The PCE is responsible for 140 computing the path of the LSP and updating to the PCC with the 141 information about the path. This is the PCE Initiated mode 142 [RFC8281]. 144 Note that protection LSP can be established (signaled) prior to the 145 failure (in which case the LSP is said to be in standby mode 146 [RFC4427]) or post failure of the corresponding working LSP according 147 to the operator choice/policy. 149 [I-D.ietf-pce-association-group] introduces a generic mechanism to 150 create a grouping of LSPs which can then be used to define 151 associations between a set of LSPs that is equally applicable to 152 stateful PCE (active and passive modes) and stateless PCE. 154 This document specifies a PCEP extension to associate one working LSP 155 with one or more protection LSPs using the generic association 156 mechanism. 158 This document describes a PCEP extension to associate protection LSPs 159 by creating Path Protection Association Group (PPAG) and encoding 160 this association in PCEP messages for stateful PCEP sessions. 162 1.1. Requirements Language 164 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 165 "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and 166 "OPTIONAL" in this document are to be interpreted as described in BCP 167 14 [RFC2119] [RFC8174] when, and only when, they appear in all 168 capitals, as shown here. 170 2. Terminology 172 The following terminologies are used in this document: 174 ERO: Explicit Route Object. 176 LSP: Label Switched Path. 178 PCC: Path Computation Client. 180 PCE: Path Computation Element 182 PCEP: Path Computation Element Protocol. 184 PPAG: Path Protection Association Group. 186 TLV: Type, Length, and Value. 188 3. PCEP Extensions 190 3.1. Path Protection Association Type 192 LSPs are not associated by listing the other LSPs with which they 193 interact, but rather by making them belong to an association group 194 referred to as "Path Protection Association Group" (PPAG) in this 195 document. All LSPs join a PPAG individually. PPAG is based on the 196 generic Association object used to associate two or more LSPs 197 specified in [I-D.ietf-pce-association-group]. A member of a PPAG 198 can take the role of working or protection LSP. This document 199 defines a new association type called "Path Protection Association 200 Type" of value TBD1. A PPAG can have one working LSP and/or one or 201 more protection LSPs. The source, destination and Tunnel ID (as 202 carried in LSP-IDENTIFIERS TLV [RFC8231], with description as per 203 [RFC3209]) of all LSPs within a PPAG MUST be the same. As per 204 [RFC3209], TE tunnel is used to associate a set of LSPs during 205 reroute or to spread a traffic trunk over multiple paths. 207 The format of the Association object used for PPAG is specified in 208 [I-D.ietf-pce-association-group]. 210 This document defines a new Association type, the Path Protection 211 Association type, value will be assigned by IANA (TBD1). 213 This Association-Type is dynamic in nature and created by the PCC or 214 PCE for the LSPs belonging to the same TE tunnel (as described in 215 [RFC3209]) originating at the same head node and terminating at the 216 same destination. These associations are conveyed via PCEP messages 217 to the PCEP peer. Operator-configured Association Range MUST NOT be 218 set for this association-type and MUST be ignored. 220 3.2. Path Protection Association TLV 222 The Path Protection Association TLV is an optional TLV for use with 223 the Path Protection Association Object Type. The Path Protection 224 Association TLV MUST NOT be present more than once. If it appears 225 more than once, only the first occurrence is processed and any others 226 MUST be ignored. 228 The Path Protection Association TLV follows the PCEP TLV format of 229 [RFC5440]. 231 The type (16 bits) of the TLV is to be assigned by IANA. The length 232 field is 16 bit-long and has a fixed value of 4. 234 The value comprises a single field, the Path Protection Association 235 Flags (32 bits), where each bit represents a flag option. 237 The format of the Path Protection Association TLV (Figure 1) is as 238 follows: 240 0 1 2 3 241 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 1 242 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 243 | Type = TBD2 | Length | 244 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 245 | Path Protection Association Flags |S|P| 246 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 248 Figure 1: Path Protection Association TLV format 250 P (PROTECTION-LSP 1 bit) - Indicates whether the LSP associated with 251 the PPAG is working or protection LSP. If this flag is set, the LSP 252 is a protection LSP. 254 S (STANDBY 1 bit)- When the P flag is set, the S flag indicates 255 whether the protection LSP associated with the PPAG is in standby 256 mode. The S flag is ignored if the P flag is not set. 258 Unassigned bits are considered reserved. They MUST be set to 0 on 259 transmission and MUST be ignored on receipt. 261 If the TLV is missing, it is considered that the LSP is the working 262 LSP (i.e. P bit is unset). 264 4. Operation 266 LSPs are associated with other LSPs with which they interact by 267 adding them to a common association group via ASSOCIATION object. 268 All procedures and error-handling for the ASSOCIATION object is as 269 per [I-D.ietf-pce-association-group]. 271 4.1. State Synchronization 273 During state synchronization, a PCC MUST report all the existing path 274 protection association groups as well as any path protection flags to 275 PCE(s) as per [I-D.ietf-pce-association-group]. 277 4.2. PCC Initiated LSPs 279 A PCC can associate a set of LSPs under its control for path 280 protection purpose. Similarly, the PCC can remove on or more LSPs 281 under its control from the corresponding PPAG. In both cases, the 282 PCC must report the change in association to PCE(s) via PCRpt 283 message. A PCC can also delegate the working and protection LSPs to 284 a stateful PCE, where PCE would control the LSPs. The stateful PCE 285 could update the paths and attributes of the LSPs in the association 286 group via PCUpd message. A PCE could also update the association to 287 PCC via PCUpd message. These procedures are described in 288 [I-D.ietf-pce-association-group]. 290 4.3. PCE Initiated LSPs 292 A PCE can create/update working and protection LSPs independently. 293 As specified in [I-D.ietf-pce-association-group], Association Groups 294 can be created by both PCE and PCC. Further, a PCE can remove a 295 protection LSP from a PPAG as specified in 296 [I-D.ietf-pce-association-group]. The PCE uses PCUpd or PCInitiate 297 message to communicate the association information to the PCC. 299 4.4. Session Termination 301 As per [I-D.ietf-pce-association-group] the association information 302 is cleared along with the LSP state information. When a PCEP session 303 is terminated, after expiry of State Timeout Interval at PCC, the LSP 304 state associated with that PCEP session is reverted to operator- 305 defined default parameters or behaviors as per [RFC8231]. Same 306 procedure is also followed for the association information. On 307 session termination at the PCE, when the LSP state reported by PCC is 308 cleared, the association information is also cleared as per 309 [I-D.ietf-pce-association-group]. Where there are no LSPs in a 310 association group, the association is considered to be deleted.. 312 4.5. Error Handling 314 All LSPs (working or protection) within a PPAG MUST belong to the 315 same TE Tunnel (as described in [RFC3209]) and have the same source 316 and destination. If a PCEP speaker attempts to add an LSP to a PPAG 317 and the Tunnel ID (as carried in LSP-IDENTIFIERS TLV [RFC8231], with 318 description as per [RFC3209]) or source or destination of the LSP is 319 different from the LSP(s) in the PPAG, the PCC MUST send PCErr with 320 Error-Type= 29 (Early allocation by IANA) (Association Error) 321 [I-D.ietf-pce-association-group] and Error-Value = TBD3 (Tunnel ID or 322 End points mismatch for Path Protection Association). 324 There MUST be only one working LSP within a PPAG. If a PCEP Speaker 325 attempts to add another working LSP, the PCEP peer MUST send PCErr 326 with Error-Type=29 (Early allocation by IANA) (Association Error) 327 [I-D.ietf-pce-association-group] and Error-Value = TBD4 (Attempt to 328 add another working LSP for Path Protection Association). 330 5. Other considerations 332 The working and protection LSPs are typically resource disjoint 333 (e.g., node, srlg disjoint). This ensures that a single failure will 334 not affect both the working and protection LSPs.The disjoint 335 requirement for a group of LSPs is handled via another association 336 type called "Disjointness Association", as described in 337 [I-D.ietf-pce-association-diversity]. The diversity requirements for 338 the the protection LSP are also handled by including both ASSOCIATION 339 object identifying both the protection association group and disjoint 340 association group for the group of LSPs. 342 6. IANA considerations 344 6.1. Association Type 346 This document defines a new association type, originally defined in 347 [I-D.ietf-pce-association-group], for path protection. IANA is 348 requested to make the assignment of a new value for the sub-registry 349 "ASSOCIATION Type Field" (request to be created in 350 [I-D.ietf-pce-association-group]), as follows: 352 +----------------------+-------------------------+------------------+ 353 | Association Type | Association Name | Reference | 354 | Value | | | 355 +----------------------+-------------------------+------------------+ 356 | TBD1 | Path Protection | This | 357 | | Association | document | 358 +----------------------+-------------------------+------------------+ 360 6.2. PPAG TLV 362 This document defines a new TLV for carrying additional information 363 of LSPs within a path protection association group. IANA is 364 requested to make the assignment of a new value for the existing 365 "PCEP TLV Type Indicators" registry as follows: 367 +---------------+-----------------------------------+---------------+ 368 | TLV Type | TLV Name | Reference | 369 | Value | | | 370 +---------------+-----------------------------------+---------------+ 371 | TBD2 | Path Protection Association Group | This document | 372 | | TLV | | 373 +---------------+-----------------------------------+---------------+ 375 This document requests that a new sub-registry, named "Path 376 protection Association Group TLV Flag Field", is created within the 377 "Path Computation Element Protocol (PCEP) Numbers" registry to manage 378 the Flag field in the Path Protection Association Group TLV. New 379 values are to be assigned by Standards Action [RFC8126]. Each bit 380 should be tracked with the following qualities: 382 Each bit should be tracked with the following qualities: 384 o Bit number (count from 0 as the most significant bit) 386 o Name flag 388 o Reference 390 +------------+--------------------+----------------+ 391 | Bit Number | Name | Reference | 392 +------------+--------------------+----------------+ 393 | 31 | P - PROTECTION-LSP | This document | 394 | 30 | S - STANDBY | This document | 395 +------------+--------------------+----------------+ 397 Table 1: PPAG TLV 399 6.3. PCEP Errors 401 This document defines new Error-Type and Error-Value related to path 402 protection association. IANA is requested to allocate new error 403 values within the "PCEP-ERROR Object Error Types and Values" sub- 404 registry of the PCEP Numbers registry, as follows: 406 +------------+-------------------+----------------------------------+ 407 | Error-Type | Meaning | Reference | 408 +------------+-------------------+----------------------------------+ 409 | 29 | Association error | [I-D.ietf-pce-association-group] | 410 | | Error-value=TBD3: | This document | 411 | | Tunnel ID or End | | 412 | | points mismatch | | 413 | | for Path | | 414 | | Protection | | 415 | | Association | | 416 | | Error-value=TBD4: | This document | 417 | | Attempt to add | | 418 | | another working | | 419 | | LSP for Path | | 420 | | Protection | | 421 | | Association | | 422 +------------+-------------------+----------------------------------+ 424 7. Security Considerations 426 The security considerations described in [RFC8231], [RFC8281], and 427 [RFC5440] apply to the extensions described in this document as well. 428 Additional considerations related to associations where a malicious 429 PCEP speaker could be spoofed and could be used as an attack vector 430 by creating associations is described in 431 [I-D.ietf-pce-association-group]. Thus securing the PCEP session 432 using Transport Layer Security (TLS) [RFC8253], as per the 433 recommendations and best current practices in [RFC7525], is 434 RECOMMENDED. 436 8. Manageability Considerations 438 8.1. Control of Function and Policy 440 Mechanisms defined in this document do not imply any control or 441 policy requirements in addition to those already listed in [RFC5440], 442 [RFC8231], and [RFC8281]. 444 8.2. Information and Data Models 446 [RFC7420] describes the PCEP MIB, there are no new MIB Objects for 447 this document. 449 The PCEP YANG module [I-D.ietf-pce-pcep-yang] supports associations. 451 8.3. Liveness Detection and Monitoring 453 Mechanisms defined in this document do not imply any new liveness 454 detection and monitoring requirements in addition to those already 455 listed in [RFC5440], [RFC8231], and [RFC8281]. 457 8.4. Verify Correct Operations 459 Mechanisms defined in this document do not imply any new operation 460 verification requirements in addition to those already listed in 461 [RFC5440], [RFC8231], and [RFC8281]. 463 8.5. Requirements On Other Protocols 465 Mechanisms defined in this document do not imply any new requirements 466 on other protocols. 468 8.6. Impact On Network Operations 470 Mechanisms defined in this document do not have any impact on network 471 operations in addition to those already listed in [RFC5440], 472 [RFC8231], and [RFC8281]. 474 9. Acknowledgments 476 We would like to thank Jeff Tantsura and Xian Zhang for their 477 contributions to this document. 479 10. References 481 10.1. Normative References 483 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 484 Requirement Levels", BCP 14, RFC 2119, 485 DOI 10.17487/RFC2119, March 1997, 486 . 488 [RFC3209] Awduche, D., Berger, L., Gan, D., Li, T., Srinivasan, V., 489 and G. Swallow, "RSVP-TE: Extensions to RSVP for LSP 490 Tunnels", RFC 3209, DOI 10.17487/RFC3209, December 2001, 491 . 493 [RFC5440] Vasseur, JP., Ed. and JL. Le Roux, Ed., "Path Computation 494 Element (PCE) Communication Protocol (PCEP)", RFC 5440, 495 DOI 10.17487/RFC5440, March 2009, 496 . 498 [RFC8126] Cotton, M., Leiba, B., and T. Narten, "Guidelines for 499 Writing an IANA Considerations Section in RFCs", BCP 26, 500 RFC 8126, DOI 10.17487/RFC8126, June 2017, 501 . 503 [RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 504 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, 505 May 2017, . 507 [RFC8231] Crabbe, E., Minei, I., Medved, J., and R. Varga, "Path 508 Computation Element Communication Protocol (PCEP) 509 Extensions for Stateful PCE", RFC 8231, 510 DOI 10.17487/RFC8231, September 2017, 511 . 513 [RFC8281] Crabbe, E., Minei, I., Sivabalan, S., and R. Varga, "Path 514 Computation Element Communication Protocol (PCEP) 515 Extensions for PCE-Initiated LSP Setup in a Stateful PCE 516 Model", RFC 8281, DOI 10.17487/RFC8281, December 2017, 517 . 519 [I-D.ietf-pce-association-group] 520 Minei, I., Crabbe, E., Sivabalan, S., Ananthakrishnan, H., 521 Dhody, D., and Y. Tanaka, "PCEP Extensions for 522 Establishing Relationships Between Sets of LSPs", draft- 523 ietf-pce-association-group-04 (work in progress), August 524 2017. 526 10.2. Information References 528 [RFC4427] Mannie, E., Ed. and D. Papadimitriou, Ed., "Recovery 529 (Protection and Restoration) Terminology for Generalized 530 Multi-Protocol Label Switching (GMPLS)", RFC 4427, 531 DOI 10.17487/RFC4427, March 2006, 532 . 534 [RFC4655] Farrel, A., Vasseur, J., and J. Ash, "A Path Computation 535 Element (PCE)-Based Architecture", RFC 4655, 536 DOI 10.17487/RFC4655, August 2006, 537 . 539 [RFC4657] Ash, J., Ed. and J. Le Roux, Ed., "Path Computation 540 Element (PCE) Communication Protocol Generic 541 Requirements", RFC 4657, DOI 10.17487/RFC4657, September 542 2006, . 544 [RFC7420] Koushik, A., Stephan, E., Zhao, Q., King, D., and J. 545 Hardwick, "Path Computation Element Communication Protocol 546 (PCEP) Management Information Base (MIB) Module", 547 RFC 7420, DOI 10.17487/RFC7420, December 2014, 548 . 550 [RFC7525] Sheffer, Y., Holz, R., and P. Saint-Andre, 551 "Recommendations for Secure Use of Transport Layer 552 Security (TLS) and Datagram Transport Layer Security 553 (DTLS)", BCP 195, RFC 7525, DOI 10.17487/RFC7525, May 554 2015, . 556 [RFC8051] Zhang, X., Ed. and I. Minei, Ed., "Applicability of a 557 Stateful Path Computation Element (PCE)", RFC 8051, 558 DOI 10.17487/RFC8051, January 2017, 559 . 561 [RFC8253] Lopez, D., Gonzalez de Dios, O., Wu, Q., and D. Dhody, 562 "PCEPS: Usage of TLS to Provide a Secure Transport for the 563 Path Computation Element Communication Protocol (PCEP)", 564 RFC 8253, DOI 10.17487/RFC8253, October 2017, 565 . 567 [I-D.ietf-pce-pcep-yang] 568 Dhody, D., Hardwick, J., Beeram, V., and J. Tantsura, "A 569 YANG Data Model for Path Computation Element 570 Communications Protocol (PCEP)", draft-ietf-pce-pcep- 571 yang-06 (work in progress), January 2018. 573 [I-D.ietf-pce-association-diversity] 574 Litkowski, S., Sivabalan, S., Barth, C., and D. Dhody, 575 "Path Computation Element communication Protocol extension 576 for signaling LSP diversity constraint", draft-ietf-pce- 577 association-diversity-03 (work in progress), February 578 2018. 580 Authors' Addresses 582 Hariharan Ananthakrishnan 583 Packet Design 584 1 South Almaden Blvd, #1150, 585 San Jose, CA, 95113 586 USA 588 EMail: hari@packetdesign.com 590 Siva Sivabalan 591 Cisco 592 2000 Innovation Drive 593 Kananta, Ontaria K2K 3E8 594 Canada 596 EMail: msiva@cisco.com 598 Colby Barth 599 Juniper Networks 600 1194 N Mathilda Ave, 601 Sunnyvale, CA, 94086 602 USA 604 EMail: cbarth@juniper.net 605 Raveendra Torvi 606 Juniper Networks 607 1194 N Mathilda Ave, 608 Sunnyvale, CA, 94086 609 USA 611 EMail: rtorvi@juniper.net 613 Ina Minei 614 Google, Inc 615 1600 Amphitheatre Parkway 616 Mountain View, CA, 94043 617 USA 619 EMail: inaminei@google.com 621 Edward Crabbe 622 Individual Contributor 624 EMail: edward.crabbe@gmail.com 626 Dhruv Dhody 627 Huawei Technologies 628 Divyashree Techno Park, Whitefield 629 Bangalore, Karnataka 560066 630 India 632 EMail: dhruv.ietf@gmail.com