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Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 2 PCE Working Group D. Dhody 3 Internet-Draft Y. Lee 4 Intended status: Standards Track Huawei Technologies 5 Expires: July 6, 2018 D. Ceccarelli 6 Ericsson 7 January 2, 2018 9 PCEP Extension for Distribution of Link-State and TE Information. 10 draft-dhodylee-pce-pcep-ls-09 12 Abstract 14 In order to compute and provide optimal paths, Path Computation 15 Elements (PCEs) require an accurate and timely Traffic Engineering 16 Database (TED). Traditionally this TED has been obtained from a link 17 state (LS) routing protocol supporting traffic engineering 18 extensions. 20 This document extends the Path Computation Element Communication 21 Protocol (PCEP) with Link-State and TE Information. 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 July 6, 2018. 40 Copyright Notice 42 Copyright (c) 2018 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 1.1. Requirements Language . . . . . . . . . . . . . . . . . . 5 59 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 5 60 3. Applicability . . . . . . . . . . . . . . . . . . . . . . . . 5 61 4. Requirements for PCEP extension . . . . . . . . . . . . . . . 6 62 5. New Functions to distribute link-state (and TE) via PCEP . . 7 63 6. Overview of Extension to PCEP . . . . . . . . . . . . . . . . 7 64 6.1. New Messages . . . . . . . . . . . . . . . . . . . . . . 7 65 6.2. Capability Advertisement . . . . . . . . . . . . . . . . 7 66 6.3. Initial Link-State (and TE) Synchronization . . . . . . . 8 67 6.3.1. Optimizations for LS Synchronization . . . . . . . . 10 68 6.4. LS Report . . . . . . . . . . . . . . . . . . . . . . . . 11 69 7. Transport . . . . . . . . . . . . . . . . . . . . . . . . . . 11 70 8. PCEP Messages . . . . . . . . . . . . . . . . . . . . . . . . 11 71 8.1. LS Report Message . . . . . . . . . . . . . . . . . . . . 11 72 8.2. The PCErr Message . . . . . . . . . . . . . . . . . . . . 12 73 9. Objects and TLV . . . . . . . . . . . . . . . . . . . . . . . 12 74 9.1. TLV Format . . . . . . . . . . . . . . . . . . . . . . . 13 75 9.2. Open Object . . . . . . . . . . . . . . . . . . . . . . . 13 76 9.2.1. LS Capability TLV . . . . . . . . . . . . . . . . . . 13 77 9.3. LS Object . . . . . . . . . . . . . . . . . . . . . . . . 14 78 9.3.1. Routing Universe TLV . . . . . . . . . . . . . . . . 15 79 9.3.2. Route Distinguisher TLV . . . . . . . . . . . . . . . 16 80 9.3.3. Virtual Network TLV . . . . . . . . . . . . . . . . . 17 81 9.3.4. Local Node Descriptors TLV . . . . . . . . . . . . . 17 82 9.3.5. Remote Node Descriptors TLV . . . . . . . . . . . . . 18 83 9.3.6. Node Descriptors Sub-TLVs . . . . . . . . . . . . . . 19 84 9.3.7. Link Descriptors TLV . . . . . . . . . . . . . . . . 19 85 9.3.8. Prefix Descriptors TLV . . . . . . . . . . . . . . . 20 86 9.3.9. PCEP-LS Attributes . . . . . . . . . . . . . . . . . 21 87 9.3.9.1. Node Attributes TLV . . . . . . . . . . . . . . . 21 88 9.3.9.2. Link Attributes TLV . . . . . . . . . . . . . . . 22 89 9.3.9.3. Prefix Attributes TLV . . . . . . . . . . . . . . 24 90 9.3.10. Removal of an Attribute . . . . . . . . . . . . . . . 25 91 10. Other Considerations . . . . . . . . . . . . . . . . . . . . 25 92 10.1. Inter-AS Links . . . . . . . . . . . . . . . . . . . . . 25 93 11. Security Considerations . . . . . . . . . . . . . . . . . . . 25 94 12. Manageability Considerations . . . . . . . . . . . . . . . . 25 95 12.1. Control of Function and Policy . . . . . . . . . . . . . 26 96 12.2. Information and Data Models . . . . . . . . . . . . . . 26 97 12.3. Liveness Detection and Monitoring . . . . . . . . . . . 26 98 12.4. Verify Correct Operations . . . . . . . . . . . . . . . 27 99 12.5. Requirements On Other Protocols . . . . . . . . . . . . 27 100 12.6. Impact On Network Operations . . . . . . . . . . . . . . 27 101 13. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 27 102 13.1. PCEP Messages . . . . . . . . . . . . . . . . . . . . . 27 103 13.2. PCEP Objects . . . . . . . . . . . . . . . . . . . . . . 27 104 13.3. LS Object . . . . . . . . . . . . . . . . . . . . . . . 28 105 13.4. PCEP-Error Object . . . . . . . . . . . . . . . . . . . 28 106 13.5. PCEP TLV Type Indicators . . . . . . . . . . . . . . . . 29 107 13.6. PCEP-LS Sub-TLV Type Indicators . . . . . . . . . . . . 29 108 14. TLV/Sub-TLV Code Points Summary . . . . . . . . . . . . . . . 32 109 15. Implementation Status . . . . . . . . . . . . . . . . . . . . 32 110 15.1. Hierarchical Transport PCE controllers . . . . . . . . . 32 111 15.2. ONOS-based Controller (MDSC and PNC) . . . . . . . . . . 33 112 16. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 33 113 17. References . . . . . . . . . . . . . . . . . . . . . . . . . 33 114 17.1. Normative References . . . . . . . . . . . . . . . . . . 33 115 17.2. Informative References . . . . . . . . . . . . . . . . . 34 116 Appendix A. Relevant OSPF TLV and sub-TLV . . . . . . . . . . . 38 117 Appendix B. Examples . . . . . . . . . . . . . . . . . . . . . . 39 118 B.1. All Nodes . . . . . . . . . . . . . . . . . . . . . . . . 39 119 B.2. Designated Node . . . . . . . . . . . . . . . . . . . . . 40 120 B.3. Between PCEs . . . . . . . . . . . . . . . . . . . . . . 40 121 Appendix C. Contributor Addresses . . . . . . . . . . . . . . . 42 122 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 42 124 1. Introduction 126 In Multiprotocol Label Switching (MPLS) and Generalized MPLS (GMPLS), 127 a Traffic Engineering Database (TED) is used in computing paths for 128 connection oriented packet services and for circuits. The TED 129 contains all relevant information that a Path Computation Element 130 (PCE) needs to perform its computations. It is important that the 131 TED be complete and accurate each time, the PCE performs a path 132 computation. 134 In MPLS and GMPLS, interior gateway routing protocols (IGPs) have 135 been used to create and maintain a copy of the TED at each node 136 running the IGP. One of the benefits of the PCE architecture 137 [RFC4655] is the use of computationally more sophisticated path 138 computation algorithms and the realization that these may need 139 enhanced processing power not necessarily available at each node 140 participating in an IGP. 142 Section 4.3 of [RFC4655] describes the potential load of the TED on a 143 network node and proposes an architecture where the TED is maintained 144 by the PCE rather than the network nodes. However, it does not 145 describe how a PCE would obtain the information needed to populate 146 its TED. PCE may construct its TED by participating in the IGP 147 ([RFC3630] and [RFC5305] for MPLS-TE; [RFC4203] and [RFC5307] for 148 GMPLS). An alternative is offered by BGP-LS [RFC7752] . 150 [RFC8231] describes a set of extensions to PCEP to provide stateful 151 control. A stateful PCE has access to not only the information 152 carried by the network's Interior Gateway Protocol (IGP), but also 153 the set of active paths and their reserved resources for its 154 computations. PCC can delegate the rights to modify the LSP 155 parameters to an Active Stateful PCE. This requires PCE to quickly 156 be updated on any changes in the Topology and TEDB, so that PCE can 157 meet the need for updating LSPs effectively and in a timely manner. 158 The fastest way for a PCE to be updated on TED changes is via a 159 direct interface with each network node and with incremental update 160 from each network node with only the attribute that is modified. 162 [RFC8281] describes the setup, maintenance and teardown of PCE- 163 initiated LSPs under the stateful PCE model, without the need for 164 local configuration on the PCC, thus allowing for a dynamic network 165 that is centrally controlled and deployed. This model requires 166 timely topology and TED update at the PCE. 168 [RFC5440] describes the specifications for the Path Computation 169 Element Communication Protocol (PCEP). PCEP specifies the 170 communication between a Path Computation Client (PCC) and a Path 171 Computation Element (PCE), or between two PCEs based on the PCE 172 architecture [RFC4655]. 174 This document describes a mechanism by which Link State and TE 175 information can be collected from networks and shared with PCE using 176 the PCEP itself. This is achieved using a new PCEP message format. 177 The mechanism is applicable to physical and virtual links as well as 178 further subjected to various policies. 180 A network node maintains one or more databases for storing link-state 181 and TE information about nodes and links in any given area. Link 182 attributes stored in these databases include: local/remote IP 183 addresses, local/ remote interface identifiers, link metric and TE 184 metric, link bandwidth, reservable bandwidth, per CoS class 185 reservation state, preemption and Shared Risk Link Groups (SRLG). 186 The node's PCEP process can retrieve topology from these databases 187 and distribute it to a PCE, either directly or via another PCEP 188 Speaker, using the encoding specified in this document. 190 Further [RFC6805] describes Hierarchical-PCE architecture, where a 191 parent PCE maintains a domain topology map. To build this domain 192 topology map, the child PCE can carry the border nodes and inter- 193 domain link information to the parent PCE using the mechanism 194 described in this document. Further as described in 195 [I-D.ietf-pce-applicability-actn], the child PCE can also transport 196 abstract Link-State and TE information from child PCE to a Parent PCE 197 using the mechanism described in this document to build an abstract 198 topology at the parent PCE. 200 [RFC8231] describe LSP state synchronization between PCCs and PCEs in 201 case of stateful PCE. This document does not make any change to the 202 LSP state synchronization process. The mechanism described in this 203 document are on top of the existing LSP state synchronization. 205 1.1. Requirements Language 207 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 208 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this 209 document are to be interpreted as described in [RFC2119]. 211 2. Terminology 213 The terminology is as per [RFC4655] and [RFC5440]. 215 3. Applicability 217 The mechanism specified in this draft is applicable to deployments: 219 o Where there is no IGP or BGP-LS running in the network. 221 o Where there is no IGP or BGP-LS running at the PCE to learn link- 222 state and TE information. 224 o Where there is IGP or BGP-LS running but with a need for a faster 225 TE and link-state population and convergence at the PCE. 227 * A PCE may receive partial information (say basic TE, link- 228 state) from IGP and other information (optical and impairment) 229 from PCEP. 231 * A PCE may receive an incremental update (as opposed to the 232 entire information of the node/link). 234 * A PCE may receive full information from both existing mechanism 235 (IGP or BGP) and PCEP. 237 o Where there is a need for transporting (abstract) Link-State and 238 TE information from child PCE to a Parent PCE in H-PCE [RFC6805]; 239 as well as for Physical Network Controller (PNC) to Multi-Domain 240 Service Coordinator (MDSC) in Abstraction and Control of TE 241 Networks (ACTN) [I-D.ietf-teas-actn-framework]. 243 A PCC may further choose to send only local information or both local 244 and remote learned information. 246 How a PCE manages the link-state (and TE) information is 247 implementation specific and thus out of scope of this document. 249 The prefix information in PCEP-LS can also help in determining the 250 domain of the endpoints in H-PCE (and ACTN). Section 4.5 of 251 [RFC6805] describe various mechanism and procedures that might be 252 used, PCEP-LS provides a simple mechanism to exchange this 253 information. 255 4. Requirements for PCEP extension 257 Following key requirements associated with link-state (and TE) 258 distribution are identified for PCEP: 260 1. The PCEP speaker supporting this draft MUST be a mechanism to 261 advertise the Link-State (and TE) distribution capability. 263 2. PCC supporting this draft MUST have the capability to report the 264 link-state (and TE) information to the PCE. This includes self 265 originated information and remote information learned via routing 266 protocols. PCC MUST be capable to do the initial bulk sync at 267 the time of session initialization as well as changes after. 269 3. A PCE MAY learn link-state (and TE) from PCEP as well as from 270 existing mechanism like IGP/BGP-LS. PCEP extension MUST have a 271 mechanism to link the information learned via other means. There 272 MUST NOT be any changes to the existing link-state (and TE) 273 population mechanism via IGP/BGP-LS. PCEP extension SHOULD keep 274 the properties in a protocol (IGP or BGP-LS) neutral way, such 275 that an implementation may not need to know about any OSPF or IS- 276 IS or BGP protocol specifics. 278 4. It SHOULD be possible to encode only the changes in link-state 279 (and TE) properties (after the initial sync) in PCEP messages. 281 5. The same mechanism should be used for both MPLS TE as well as 282 GMPLS, optical and impairment aware properties. 284 6. The same mechanism should be used for PCE to PCE Link-state (and 285 TE) synchronization. 287 5. New Functions to distribute link-state (and TE) via PCEP 289 Several new functions are required in PCEP to support distribution of 290 link-state (and TE) information. A function can be initiated either 291 from a PCC towards a PCE (C-E) or from a PCE towards a PCC (E-C). 292 The new functions are: 294 o Capability advertisement (E-C,C-E): both the PCC and the PCE must 295 announce during PCEP session establishment that they support PCEP 296 extensions for distribution of link-state (and TE) information 297 defined in this document. 299 o Link-State (and TE) synchronization (C-E): after the session 300 between the PCC and a PCE is initialized, the PCE must learn Link- 301 State (and TE) information before it can perform path 302 computations. In case of stateful PCE it is RECOMENDED that this 303 operation be done before LSP state synchronization. 305 o Link-State (and TE) Report (C-E): a PCC sends a LS (and TE) report 306 to a PCE whenever the Link-State and TE information changes. 308 6. Overview of Extension to PCEP 310 6.1. New Messages 312 In this document, we define a new PCEP messages called LS Report 313 (LSRpt), a PCEP message sent by a PCC to a PCE to report link-state 314 (and TE) information. Each LS Report in a LSRpt message can contain 315 the node or link properties. An unique PCEP specific LS identifier 316 (LS-ID) is also carried in the message to identify a node or link and 317 that remains constant for the lifetime of a PCEP session. This 318 identifier on its own is sufficient when no IGP or BGP-LS running in 319 the network for PCE to learn link-state (and TE) information. Incase 320 PCE learns some information from PCEP and some from the existing 321 mechanism, the PCC SHOULD include the mapping of IGP or BGP-LS 322 identifier to map the information populated via PCEP with IGP/BGP-LS. 323 See Section 8.1 for details. 325 6.2. Capability Advertisement 327 During PCEP Initialization Phase, PCEP Speakers (PCE or PCC) 328 advertise their support of LS (and TE) distribution via PCEP 329 extensions. A PCEP Speaker includes the "LS Capability" TLV, 330 described in Section 9.2.1, in the OPEN Object to advertise its 331 support for PCEP-LS extensions. The presence of the LS Capability 332 TLV in PCC's OPEN Object indicates that the PCC is willing to send LS 333 Reports whenever local link-state (and TE) information changes. The 334 presence of the LS Capability TLV in PCE's OPEN message indicates 335 that the PCE is interested in receiving LS Reports whenever local 336 link-state (and TE) information changes. 338 The PCEP protocol extensions for LS (and TE) distribution MUST NOT be 339 used if one or both PCEP Speakers have not included the LS Capability 340 TLV in their respective OPEN message. If the PCE that supports the 341 extensions of this draft but did not advertise this capability, then 342 upon receipt of a LSRpt message from the PCC, it SHOULD generate a 343 PCErr with error-type 19 (Invalid Operation), error-value TBD1 344 (Attempted LS Report if LS capability was not advertised) and it will 345 terminate the PCEP session. 347 The LS reports sent by PCC MAY carry the remote link-state (and TE) 348 information learned via existing means like IGP and BGP-LS only if 349 both PCEP Speakers set the R (remote) Flag in the "LS Capability" TLV 350 to 'Remote Allowed (R Flag = 1)'. If this is not the case and LS 351 reports carry remote link-state (and TE) information, then a PCErr 352 with error-type 19 (Invalid Operation) and error-value TBD1 353 (Attempted LS Report if LS remote capability was not advertised) and 354 it will terminate the PCEP session. 356 6.3. Initial Link-State (and TE) Synchronization 358 The purpose of LS Synchronization is to provide a checkpoint-in- time 359 state replica of a PCC's link-state (and TE) data base in a PCE. 360 State Synchronization is performed immediately after the 361 Initialization phase (see [RFC5440]). In case of stateful PCE 362 ([RFC8231]) it is RECOMENDED that the LS synchronization should be 363 done before LSP state synchronization. 365 During LS Synchronization, a PCC first takes a snapshot of the state 366 of its database, then sends the snapshot to a PCE in a sequence of LS 367 Reports. Each LS Report sent during LS Synchronization has the SYNC 368 Flag in the LS Object set to 1. The end of synchronization marker is 369 a LSRpt message with the SYNC Flag set to 0 for an LS Object with LS- 370 ID equal to the reserved value 0. If the PCC has no link-state to 371 synchronize, it will only send the end of synchronization marker. 373 Either the PCE or the PCC MAY terminate the session using the PCEP 374 session termination procedures during the synchronization phase. If 375 the session is terminated, the PCE MUST clean up state it received 376 from this PCC. The session re-establishment MUST be re-attempted per 377 the procedures defined in [RFC5440], including use of a back-off 378 timer. 380 If the PCC encounters a problem which prevents it from completing the 381 LS synchronization, it MUST send a PCErr message with error-type TBD2 382 (LS Synchronization Error) and error-value 2 (indicating an internal 383 PCC error) to the PCE and terminate the session. 385 The PCE does not send positive acknowledgements for properly received 386 LS synchronization messages. It MUST respond with a PCErr message 387 with error-type TBD2 (LS Synchronization Error) and error-value 1 388 (indicating an error in processing the LSRpt) if it encounters a 389 problem with the LS Report it received from the PCC and it MUST 390 terminate the session. 392 The LS reports can carry local as well as remote link-state (and TE) 393 information depending on the R flag in LS capability TLV. 395 The successful LS Synchronization sequences is shown in Figure 1. 397 +-+-+ +-+-+ 398 |PCC| |PCE| 399 +-+-+ +-+-+ 400 | | 401 |-----LSRpt, SYNC=1----->| (Sync start) 402 | | 403 |-----LSRpt, SYNC=1----->| 404 | . | 405 | . | 406 | . | 407 |-----LSRpt, SYNC=1----->| 408 | . | 409 | . | 410 | . | 411 | | 412 |-----LSRpt, SYNC=0----->| (End of sync marker 413 | | LS Report 414 | | for LS-ID=0) 415 | | (Sync done) 417 Figure 1: Successful LS synchronization 419 The sequence where the PCE fails during the LS Synchronization phase 420 is shown in Figure 2. 422 +-+-+ +-+-+ 423 |PCC| |PCE| 424 +-+-+ +-+-+ 425 | | 426 |-----LSRpt, SYNC=1----->| 427 | | 428 |-----LSRpt, SYNC=1----->| 429 | . | 430 | . | 431 | . | 432 |-----LSRpt, SYNC=1----->| 433 | | 434 |---LSRpt,SYNC=1 | 435 | \ ,-PCErr---| 436 | \ / | 437 | \/ | 438 | /\ | 439 | / `-------->| (Ignored) 440 |<--------` | 442 Figure 2: Failed LS synchronization (PCE failure) 444 The sequence where the PCC fails during the LS Synchronization phase 445 is shown in Figure 3. 447 +-+-+ +-+-+ 448 |PCC| |PCE| 449 +-+-+ +-+-+ 450 | | 451 |-----LSRpt, SYNC=1----->| 452 | | 453 |-----LSRpt, SYNC=1----->| 454 | . | 455 | . | 456 | . | 457 |-------- PCErr--------->| 458 | | 460 Figure 3: Failed LS synchronization (PCC failure) 462 6.3.1. Optimizations for LS Synchronization 464 These optimizations are described in 465 [I-D.kondreddy-pce-pcep-ls-sync-optimizations]. 467 6.4. LS Report 469 The PCC MUST report any changes in the link-state (and TE) 470 information to the PCE by sending a LS Report carried on a LSRpt 471 message to the PCE. Each node and Link would be uniquely identified 472 by a PCEP LS identifier (LS-ID). The LS reports may carry local as 473 well as remote link-state (and TE) information depending on the R 474 flag in LS capability TLV. In case R flag is set, It MAY also 475 include the mapping of IGP or BGP-LS identifier to map the 476 information populated via PCEP with IGP/BGP-LS. 478 More details about LSRpt message are in Section 8.1. 480 7. Transport 482 A permanent PCEP session MUST be established between a PCE and PCC 483 supporting link-state (and TE) distribution via PCEP. In the case of 484 session failure, session re-establishment MUST be re-attempted per 485 the procedures defined in [RFC5440]. 487 8. PCEP Messages 489 As defined in [RFC5440], a PCEP message consists of a common header 490 followed by a variable-length body made of a set of objects that can 491 be either mandatory or optional. An object is said to be mandatory 492 in a PCEP message when the object must be included for the message to 493 be considered valid. For each PCEP message type, a set of rules is 494 defined that specify the set of objects that the message can carry. 495 An implementation MUST form the PCEP messages using the object 496 ordering specified in this document. 498 8.1. LS Report Message 500 A PCEP LS Report message (also referred to as LSRpt message) is a 501 PCEP message sent by a PCC to a PCE to report the link-state (and TE) 502 information. A LSRpt message can carry more than one LS Reports. 503 The Message-Type field of the PCEP common header for the LSRpt 504 message is set to [TBD3]. 506 The format of the LSRpt message is as follows: 508 ::= 509 510 Where: 512 ::= [] 513 The LS object is a mandatory object which carries LS information of a 514 node or a link. Each LS object has an unique LS-ID as described in 515 Section 9.3. If the LS object is missing, the receiving PCE MUST 516 send a PCErr message with Error-type=6 (Mandatory Object missing) and 517 Error-value=[TBD4] (LS object missing). 519 A PCE may choose to implement a limit on the LS information a single 520 PCC can populate. If a LSRpt is received that causes the PCE to 521 exceed this limit, it MUST send a PCErr message with error-type 19 522 (invalid operation) and error-value 4 (indicating resource limit 523 exceeded) in response to the LSRpt message triggering this condition 524 and SHOULD terminate the session. 526 8.2. The PCErr Message 528 If a PCEP speaker has advertised the LS capability on the PCEP 529 session, the PCErr message MAY include the LS object. If the error 530 reported is the result of an LS report, then the LS-ID number MUST be 531 the one from the LSRpt that triggered the error. 533 The format of a PCErr message from [RFC5440] is extended as follows: 535 The format of the PCErr message is as follows: 537 ::= 538 ( [] ) | 539 [] 541 ::=[] 543 ::=[ | ] 544 546 ::=[] 548 ::=[] 550 ::=[] 552 9. Objects and TLV 554 The PCEP objects defined in this document are compliant with the PCEP 555 object format defined in [RFC5440]. The P flag and the I flag of the 556 PCEP objects defined in this document MUST always be set to 0 on 557 transmission and MUST be ignored on receipt since these flags are 558 exclusively related to path computation requests. 560 9.1. TLV Format 562 The TLV and the sub-TLV format (and padding) in this document, is as 563 per section 7.1 of [RFC5440]. 565 9.2. Open Object 567 This document defines a new optional TLV for use in the OPEN Object. 569 9.2.1. LS Capability TLV 571 The LS-CAPABILITY TLV is an optional TLV for use in the OPEN Object 572 for link-state (and TE) distribution via PCEP capability 573 advertisement. Its format is shown in the following figure: 575 0 1 2 3 576 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 1 577 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 578 | Type=[TBD5] | Length=4 | 579 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 580 | Flags |R| 581 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 583 The type of the TLV is [TBD5] and it has a fixed length of 4 octets. 585 The value comprises a single field - Flags (32 bits): 587 o R (remote - 1 bit): if set to 1 by a PCC, the R Flag indicates 588 that the PCC allows reporting of remote LS information learned via 589 other means like IGP and BGP-LS; if set to 1 by a PCE, the R Flag 590 indicates that the PCE is capable of receiving remote LS 591 information (from the PCC point of view). The R Flag must be 592 advertised by both a PCC and a PCE for LSRpt messages to report 593 remote as well as local LS information on a PCEP session. The 594 TLVs related to IGP/BGP-LS identifier MUST be encoded when both 595 PCEP speakers have the R Flag set. 597 Unassigned bits are considered reserved. They MUST be set to 0 on 598 transmission and MUST be ignored on receipt. 600 Advertisement of the LS capability implies support of local link- 601 state (and TE) distribution, as well as the objects, TLVs and 602 procedures defined in this document. 604 9.3. LS Object 606 The LS (link-state) object MUST be carried within LSRpt messages and 607 MAY be carried within PCErr messages. The LS object contains a set 608 of fields used to specify the target node or link. It also contains 609 a flag indicating to a PCE that the LS synchronization is in 610 progress. The TLVs used with the LS object correlate with the IGP/ 611 BGP-LS encodings. 613 LS Object-Class is [TBD6]. 615 Four Object-Type values are defined for the LS object so far: 617 o LS Node: LS Object-Type is 1. 619 o LS Link: LS Object-Type is 2. 621 o LS IPv4 Topology Prefix: LS Object-Type is 3. 623 o LS IPv6 Topology Prefix: LS Object-Type is 4. 625 The format of all types of LS object is as follows: 627 0 1 2 3 628 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 1 629 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 630 | Protocol-ID | Flag |R|S| 631 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 632 | LS-ID | 633 | | 634 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 635 // TLVs // 636 | | 637 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 639 Protocol-ID (8-bit): The field provide the source information. The 640 protocol could be an IGP, BGP-LS or an abstraction algorithm. Incase 641 PCC only provides local information of the PCC, it MUST use Protocol- 642 ID as Direct. The following values are defined (some of them are 643 same as [RFC7752]): 645 +-------------+----------------------------------+ 646 | Protocol-ID | Source protocol | 647 +-------------+----------------------------------+ 648 | 1 | IS-IS Level 1 | 649 | 2 | IS-IS Level 2 | 650 | 3 | OSPFv2 | 651 | 4 | Direct | 652 | 5 | Static configuration | 653 | 6 | OSPFv3 | 654 | 7 | BGP-LS | 655 | 8 | PCEP-LS | 656 | 9 | Abstraction | 657 | 10 | Unspecified | 658 +-------------+----------------------------------+ 660 Flags (24-bit): 662 o S (SYNC - 1 bit): the S Flag MUST be set to 1 on each LSRpt sent 663 from a PCC during LS Synchronization. The S Flag MUST be set to 0 664 in other LSRpt messages sent from the PCC. 666 o R (Remove - 1 bit): On LSRpt messages the R Flag indicates that 667 the node/link/prefix has been removed from the PCC and the PCE 668 SHOULD remove from its database. Upon receiving an LS Report with 669 the R Flag set to 1, the PCE SHOULD remove all state for the 670 node/link/prefix identified by the LS Identifiers from its 671 database. 673 LS-ID(64-bit): A PCEP-specific identifier for the node or link or 674 prefix information. A PCC creates an unique LS-ID for each 675 node/link/prefix that is constant for the lifetime of a PCEP session. 676 The PCC will advertise the same LS-ID on all PCEP sessions it 677 maintains at a given times. All subsequent PCEP messages then 678 address the node/link/prefix by the LS-ID. The values of 0 and 679 0xFFFFFFFFFFFFFFFF are reserved. 681 Unassigned bits are considered reserved. They MUST be set to 0 on 682 transmission and MUST be ignored on receipt. 684 TLVs that may be included in the LS Object are described in the 685 following sections. 687 9.3.1. Routing Universe TLV 689 In case of remote link-state (and TE) population when existing IGP/ 690 BGP-LS are also used, OSPF and IS-IS may run multiple routing 691 protocol instances over the same link as described in [RFC7752]. See 692 [RFC8202] and [RFC6549] for more information. These instances define 693 independent "routing universes". The 64-Bit 'Identifier' field is 694 used to identify the "routing universe" where the LS object belongs. 695 The LS objects representing IGP objects (nodes or links or prefix) 696 from the same routing universe MUST have the same 'Identifier' value; 697 LS objects with different 'Identifier' values MUST be considered to 698 be from different routing universes. 700 The format of the optional ROUTING-UNIVERSE TLV is shown in the 701 following figure: 703 0 1 2 3 704 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 1 705 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 706 | Type=[TBD7] | Length=8 | 707 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 708 | Identifier | 709 | | 710 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 712 Below table lists the 'Identifier' values that are defined as well- 713 known in this draft (same as [RFC7752]). 715 +------------+-----------------------------------+ 716 | Identifier | Routing Universe | 717 +------------+-----------------------------------+ 718 | 0 | Default Layer 3 Routing topology | 719 | 1-31 | Reserved | 720 +------------+-----------------------------------+ 722 If this TLV is not present the default value 0 is assumed. 724 9.3.2. Route Distinguisher TLV 726 To allow identification of VPN link, node and prefix information in 727 PCEP-LS, a Route Distinguisher (RD) [RFC4364] is used. The LS 728 objects from the same VPN MUST have the same RD; LS objects with 729 different RD values MUST be considered to be from different VPNs. 731 The format of the optional ROUTE-DISTINGUISHER TLV is shown in the 732 following figure: 734 0 1 2 3 735 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 1 736 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 737 | Type=[TBD15] | Length=8 | 738 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 739 | Route Distinguisher | 740 | | 741 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 743 The format of RD is as per [RFC4364]. 745 9.3.3. Virtual Network TLV 747 To realize ACTN, the MDSC needs to build an multi-domain topology. 748 This topology is best served, if this is an abstracted view of the 749 underlying network resources of each domain. It is also important to 750 provide a customer view of network slice for each customer. There is 751 a need to control the level of abstraction based on the deployment 752 scenario and business relationship between the controllers. 754 Virtual service coordination function in ACTN incorporates customer 755 service-related knowledge into the virtual network operations in 756 order to seamlessly operate virtual networks while meeting customer's 757 service requirements. [I-D.ietf-teas-actn-requirements] describes 758 various VN operations initiated by a customer/application. In this 759 context, there is a need for associating the abstracted link state 760 and TE topology with a VN "construct" to facilitate VN operations in 761 PCE architecture. 763 VIRTUAL-NETWORK-TLV as per [I-D.leedhody-pce-vn-association] can be 764 included in LS object to identify the link, node and prefix 765 information belongs to a particular VN. 767 9.3.4. Local Node Descriptors TLV 769 As described in [RFC7752], each link is anchored by a pair of Router- 770 IDs that are used by the underlying IGP, namely, 48 Bit ISO System-ID 771 for IS-IS and 32 bit Router-ID for OSPFv2 and OSPFv3. Incase of 772 additional auxiliary Router-IDs used for TE, these MUST also be 773 included in the link attribute TLV (see Section 9.3.9.2). 775 It is desirable that the Router-ID assignments inside the Node 776 Descriptor are globally unique. Some considerations for globally 777 unique Node/Link/Prefix identifiers are described in [RFC7752]. 779 The Local Node Descriptors TLV contains Node Descriptors for the node 780 anchoring the local end of the link. This TLV MUST be included in 781 the LS Report when during a given PCEP session a node/link/prefix is 782 first reported to a PCE. A PCC sends to a PCE the first LS Report 783 either during State Synchronization, or when a new node/link/prefix 784 is learned at the PCC. The value contains one or more Node 785 Descriptor Sub-TLVs, which allows specification of a flexible key for 786 any given node/link/prefix information such that global uniqueness of 787 the node/link/prefix is ensured. 789 This TLV is applicable for all LS Object-Type. 791 0 1 2 3 792 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 1 793 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 794 | Type=[TBD8] | Length | 795 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 796 | | 797 // Node Descriptor Sub-TLVs (variable) // 798 | | 799 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 801 The value contains one or more Node Descriptor Sub-TLVs defined in 802 Section 9.3.6. 804 9.3.5. Remote Node Descriptors TLV 806 The Remote Node Descriptors contains Node Descriptors for the node 807 anchoring the remote end of the link. This TLV MUST be included in 808 the LS Report when during a given PCEP session a link is first 809 reported to a PCE. A PCC sends to a PCE the first LS Report either 810 during State Synchronization, or when a new link is learned at the 811 PCC. The length of this TLV is variable. The value contains one or 812 more Node Descriptor Sub-TLVs defined in Section 9.3.6. 814 This TLV is applicable for LS Link Object-Type. 816 0 1 2 3 817 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 1 818 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 819 | Type=[TBD9] | Length | 820 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 821 | | 822 // Node Descriptor Sub-TLVs (variable) // 823 | | 824 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 826 9.3.6. Node Descriptors Sub-TLVs 828 The Node Descriptor Sub-TLV type Type and lengths are listed in the 829 following table: 831 +----------+-------------------+----------+----------------+ 832 | Sub-TLV | Description | Length |Value defined in| 833 +----------+-------------------+----------+----------------+ 834 | 0 | Reserved | - | - | 835 | 1 | Autonomous System | 4 | [RFC7752] | 836 | 2 | BGP-LS Identifier | 4 | / section | 837 | 3 | OSPF Area-ID | 4 | 3.2.1.4 | 838 | 4 | Router-ID | Variable | | 839 +----------+-------------------+----------+----------------+ 841 The sub-TLV values in Node Descriptor TLVs are defined as follows 842 (similar to [RFC7752]): 844 o Autonomous System: opaque value (32 Bit AS Number) 846 o BGP-LS Identifier: opaque value (32 Bit ID). In conjunction with 847 ASN, uniquely identifies the BGP-LS domain as described in 848 [RFC7752]. This sub-TLV is present only if the node implements 849 BGP-LS and the ID is set by the operator. 851 o OSPF Area ID: It is used to identify the 32 Bit area to which the 852 LS object belongs. Area Identifier allows the different LS 853 objects of the same node to be discriminated. 855 o Router ID: opaque value. Usage is described in [RFC7752] as IGP 856 Router ID. In case this is not learned from IGP, it SHOULD 857 contain the unique router ID, such as TE router ID. 859 9.3.7. Link Descriptors TLV 861 The Link Descriptors TLV contains Link Descriptors for each link. 862 This TLV MUST be included in the LS Report when during a given PCEP 863 session a link is first reported to a PCE. A PCC sends to a PCE the 864 first LS Report either during State Synchronization, or when a new 865 link is learned at the PCC. The length of this TLV is variable. The 866 value contains one or more Link Descriptor Sub-TLVs. 868 The 'Link descriptor' TLVs uniquely identify a link among multiple 869 parallel links between a pair of anchor routers similar to [RFC7752]. 871 This TLV is applicable for LS Link Object-Type. 873 0 1 2 3 874 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 1 875 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 876 | Type=[TBD10] | Length | 877 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 878 | | 879 // Link Descriptor Sub-TLVs (variable) // 880 | | 881 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 883 The Link Descriptor Sub-TLV type and lengths are listed in the 884 following table: 886 +-----------+---------------------+---------------+-----------------+ 887 | Sub-TLV | Description | IS-IS TLV | Value defined | 888 | | | /Sub-TLV | in: | 889 +-----------+---------------------+---------------+-----------------+ 890 | 6 | Link Local/Remote | 22/4 | [RFC5307]/1.1 | 891 | | Identifiers | | | 892 | 7 | IPv4 interface | 22/6 | [RFC5305]/3.2 | 893 | | address | | | 894 | 8 | IPv4 neighbor | 22/8 | [RFC5305]/3.3 | 895 | | address | | | 896 | 9 | IPv6 interface | 22/12 | [RFC6119]/4.2 | 897 | | address | | | 898 | 10 | IPv6 neighbor | 22/13 | [RFC6119]/4.3 | 899 | | address | | | 900 | 5 | Multi-Topology | - | [RFC7752]/ | 901 | | identifier | | 3.2.1.5 | 902 +-----------+---------------------+---------------+-----------------+ 904 The format and semantics of the 'value' fields in most 'Link 905 Descriptor' sub-TLVs correspond to the format and semantics of value 906 fields in IS-IS Extended IS Reachability sub-TLVs, defined in 907 [RFC5305], [RFC5307] and [RFC6119]. Although the encodings for 'Link 908 Descriptor' TLVs were originally defined for IS-IS, the TLVs can 909 carry data sourced either by IS-IS or OSPF or direct. 911 The information about a link present in the LSA/LSP originated by the 912 local node of the link determines the set of sub-TLVs in the Link 913 Descriptor of the link as described in [RFC7752]. 915 9.3.8. Prefix Descriptors TLV 917 The Prefix Descriptors TLV contains Prefix Descriptors uniquely 918 identify an IPv4 or IPv6 Prefix originated by a Node. This TLV MUST 919 be included in the LS Report when during a given PCEP session a 920 prefix is first reported to a PCE. A PCC sends to a PCE the first LS 921 Report either during State Synchronization, or when a new prefix is 922 learned at the PCC. The length of this TLV is variable. 924 This TLV is applicable for LS Prefix Object-Types for both IPv4 and 925 IPv6. 927 0 1 2 3 928 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 1 929 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 930 | Type=[TBD11] | Length | 931 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 932 | | 933 // Prefix Descriptor Sub-TLVs (variable) // 934 | | 935 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 937 The value contains one or more Prefix Descriptor Sub-TLVs defined 938 below - 940 +--------------+-----------------------+----------+-----------------+ 941 | TLV Code | Description | Length | Value defined | 942 | Point | | | in: | 943 +--------------+-----------------------+----------+-----------------+ 944 | 5 | Multi-Topology | variable | [RFC7752] | 945 | | Identifier | | /3.2.1.5 | 946 | 11 | OSPF Route Type | 1 | [RFC7752] | 947 | | | | /3.2.3.1 | 948 | 12 | IP Reachability | variable | [RFC7752] | 949 | | Information | | /3.2.3.2 | 950 +--------------+-----------------------+----------+-----------------+ 952 9.3.9. PCEP-LS Attributes 954 9.3.9.1. Node Attributes TLV 956 This is an optional attribute that is used to carry node attributes. 957 This TLV is applicable for LS Node Object-Type. 959 0 1 2 3 960 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 1 961 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 962 | Type=[TBD12] | Length | 963 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 964 | | 965 // Node Attributes Sub-TLVs (variable) // 966 | | 967 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 969 The Node Attributes Sub-TLV type and lengths are listed in the 970 following table: 972 +--------------+-----------------------+----------+-----------------+ 973 | Sub TLV | Description | Length | Value defined | 974 | | | | in: | 975 +--------------+-----------------------+----------+-----------------+ 976 | 5 | Multi-Topology | variable | [RFC7752] | 977 | | Identifier | | /3.2.1.5 | 978 | 13 | Node Flag Bits | 1 | [RFC7752] | 979 | | | | /3.3.1.1 | 980 | 14 | Opaque Node | variable | [RFC7752] | 981 | | Properties | | /3.3.1.5 | 982 | 15 | Node Name | variable | [RFC7752] | 983 | | | | /3.3.1.3 | 984 | 16 | IS-IS Area Identifier | variable | [RFC7752] | 985 | | | | /3.3.1.2 | 986 | 17 | IPv4 Router-ID of | 4 | [RFC5305]/4.3 | 987 | | Local Node | | | 988 | 18 | IPv6 Router-ID of | 16 | [RFC6119]/4.1 | 989 | | Local Node | | | 990 +--------------+-----------------------+----------+-----------------+ 992 9.3.9.2. Link Attributes TLV 994 This TLV is applicable for LS Link Object-Type. The format and 995 semantics of the 'value' fields in some 'Link Attribute' sub-TLVs 996 correspond to the format and semantics of value fields in IS-IS 997 Extended IS Reachability sub-TLVs, defined in [RFC5305], [RFC5307] 998 and [RFC7752]. Although the encodings for 'Link Attribute' TLVs were 999 originally defined for IS-IS, the TLVs can carry data sourced either 1000 by IS-IS or OSPF or direct. 1002 0 1 2 3 1003 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 1004 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1005 | Type=[TBD13] | Length | 1006 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1007 | | 1008 // Link Attributes Sub-TLVs (variable) // 1009 | | 1010 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1012 The following 'Link Attribute' sub-TLVs are valid : 1014 +-----------+---------------------+--------------+------------------+ 1015 | Sub-TLV | Description | IS-IS TLV | Defined in: | 1016 | | | /Sub-TLV | | 1017 | | | BGP-LS TLV | | 1018 +-----------+---------------------+--------------+------------------+ 1019 | 17 | IPv4 Router-ID of | 134/--- | [RFC5305]/4.3 | 1020 | | Local Node | | | 1021 | 18 | IPv6 Router-ID of | 140/--- | [RFC6119]/4.1 | 1022 | | Local Node | | | 1023 | 19 | IPv4 Router-ID of | 134/--- | [RFC5305]/4.3 | 1024 | | Remote Node | | | 1025 | 20 | IPv6 Router-ID of | 140/--- | [RFC6119]/4.1 | 1026 | | Remote Node | | | 1027 | 6 | Link Local/Remote | 22/4 | [RFC5307]/1.1 | 1028 | | Identifiers | | | 1029 | 22 | Administrative | 22/3 | [RFC5305]/3.1 | 1030 | | group (color) | | | 1031 | 23 | Maximum link | 22/9 | [RFC5305]/3.3 | 1032 | | bandwidth | | | 1033 | 24 | Max. reservable | 22/10 | [RFC5305]/3.5 | 1034 | | link bandwidth | | | 1035 | 25 | Unreserved | 22/11 | [RFC5305]/3.6 | 1036 | | bandwidth | | | 1037 | 26 | TE Default Metric | 22/18 | [RFC7752] | 1038 | | | | /3.3.2.3 | 1039 | 27 | Link Protection | 22/20 | [RFC5307]/1.2 | 1040 | | Type | | | 1041 | 28 | MPLS Protocol Mask | 1094 | [RFC7752] | 1042 | | | | /3.3.2.2 | 1043 | 29 | IGP Metric | 1095 | [RFC7752] | 1044 | | | | /3.3.2.4 | 1045 | 30 | Shared Risk Link | 1096 | [RFC7752] | 1046 | | Group | | /3.3.2.5 | 1047 | 31 | Opaque link | 1097 | [RFC7752] | 1048 | | attributes | | /3.3.2.6 | 1049 | 32 | Link Name attribute | 1098 | [RFC7752] | 1050 | | | | /3.3.2.7 | 1051 | 33 | Unidirectional | 22/33 | [RFC7810]/4.1 | 1052 | | Link Delay | | | 1053 | 34 | Min/Max | 22/34 | [RFC7810]/4.2 | 1054 | | Unidirectional Link | | | 1055 | | Delay | | | 1056 | 35 | Unidirectional | 22/35 | [RFC7810]/4.3 | 1057 | | Delay Variation | | | 1058 | 36 | Unidirectional | 22/36 | [RFC7810]/4.4 | 1059 | | Link Loss | | | 1060 | 37 | Unidirectional | 22/37 | [RFC7810]/4.5 | 1061 | | Residual Bandwidth | | | 1062 | 38 | Unidirectional | 22/38 | [RFC7810]/4.6 | 1063 | | Available Bandwidth | | | 1064 | 39 | Unidirectional | 22/39 | [RFC7810]/4.7 | 1065 | | Bandwidth | | | 1066 | | Utilization | | | 1067 | 40 | Extended Admin | 22/14 | [RFC7308]/2.1 | 1068 | | Group (EAG) | | | 1069 +-----------+---------------------+--------------+------------------+ 1071 9.3.9.3. Prefix Attributes TLV 1073 This TLV is applicable for LS Prefix Object-Types for both IPv4 and 1074 IPv6. Prefixes are learned from the IGP (IS-IS or OSPF) or BGP 1075 topology with a set of IGP attributes (such as metric, route tags, 1076 etc.). This section describes the different attributes related to 1077 the IPv4/IPv6 prefixes. Prefix Attributes TLVs SHOULD be encoded in 1078 the LS Prefix Object. 1080 0 1 2 3 1081 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 1082 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1083 | Type=[TBD14] | Length | 1084 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1085 | | 1086 // Prefix Attributes Sub-TLVs (variable) // 1087 | | 1088 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1090 The following 'Prefix Attribute' sub-TLVs are valid : 1092 +-----------+---------------------+--------------+------------------+ 1093 | Sub-TLV | Description | BGP-LS TLV | Defined in: | 1094 +-----------+---------------------+--------------+------------------+ 1095 | 41 | IGP Flags | 1152 | [RFC7752] | 1096 | | | | /3.3.3.1 | 1097 | 42 | Route Tag | 1153 | [RFC7752] | 1098 | | | | /3.3.3.2 | 1099 | 43 | Extended Tag | 1154 | [RFC7752] | 1100 | | | | /3.3.3.3 | 1101 | 44 | Prefix Metric | 1155 | [RFC7752] | 1102 | | | | /3.3.3.4 | 1103 | 45 | OSPF Forwarding | 1156 | [RFC7752] | 1104 | | Address | | /3.3.3.5 | 1105 | 46 | Opaque Prefix | 1157 | [RFC7752] | 1106 | | Attribute | | /3.3.3.6 | 1107 +-----------+---------------------+--------------+------------------+ 1109 9.3.10. Removal of an Attribute 1111 One of a key objective of PCEP-LS is to encode and carry only the 1112 impacted attributes of a Node, a Link or a Prefix. To accommodate 1113 this requirement, incase of a removal of an attribute, the sub-TLV 1114 MUST be included with no 'value' field and length=0 to indicate that 1115 the attribute is removed. On receiving a sub-TLV with zero length, 1116 the receiver removes the attribute from the database. 1118 10. Other Considerations 1120 10.1. Inter-AS Links 1122 The main source of LS (and TE) information is the IGP, which is not 1123 active on inter-AS links. In some cases, the IGP may have 1124 information of inter-AS links ([RFC5392], [RFC5316]). In other 1125 cases, an implementation SHOULD provide a means to inject inter-AS 1126 links into PCEP. The exact mechanism used to provision the inter-AS 1127 links is outside the scope of this document. 1129 11. Security Considerations 1131 This document extends PCEP for LS (and TE) distribution including a 1132 new LSRpt message with new object and TLVs. Procedures and protocol 1133 extensions defined in this document do not effect the overall PCEP 1134 security model. See [RFC5440], [RFC8253]. Tampering with the LSRpt 1135 message may have an effect on path computations at PCE. It also 1136 provides adversaries an opportunity to eavesdrop and learn sensitive 1137 information and plan sophisticated attacks on the network 1138 infrastructure. The PCE implementation SHOULD provide mechanisms to 1139 prevent strains created by network flaps and amount of LS (and TE) 1140 information. Thus it is suggested that any mechanism used for 1141 securing the transmission of other PCEP message be applied here as 1142 well. As a general precaution, it is RECOMMENDED that these PCEP 1143 extensions only be activated on authenticated and encrypted sessions 1144 belonging to the same administrative authority. 1146 12. Manageability Considerations 1148 All manageability requirements and considerations listed in [RFC5440] 1149 apply to PCEP protocol extensions defined in this document. In 1150 addition, requirements and considerations listed in this section 1151 apply. 1153 12.1. Control of Function and Policy 1155 A PCE or PCC implementation MUST allow configuring the PCEP-LS 1156 capabilities as described in this document. 1158 A PCC implementation SHOULD allow configuration to suggest if remote 1159 information learned via routing protocols should be reported or not. 1161 An implementation SHOULD allow the operator to specify the maximum 1162 number of LS data to be reported. 1164 An implementation SHOULD also allow the operator to create abstracted 1165 topologies that are reported to the peers and create different 1166 abstractions for different peers. 1168 An implementation SHOULD allow the operator to configure a 64-bit 1169 Instance-ID for Routing Universe TLV. 1171 12.2. Information and Data Models 1173 An implementation SHOULD allow the operator to view the LS 1174 capabilities advertised by each peer. To serve this purpose, the 1175 PCEP YANG module [I-D.ietf-pce-pcep-yang]" can be extended to include 1176 advertised capabilities. 1178 An implementation SHOULD also provide the statistics: 1180 o Total number of LSRpt sent/received, as well as per neighbor 1182 o Number of error received for LSRpt, per neighbor 1184 o Total number of locally originated Link-State Information 1186 These statistics should be recorded as absolute counts since system 1187 or session start time. An implementation MAY also enhance this 1188 information by recording peak per-second counts in each case. 1190 An operator SHOULD define an import policy to limit inbound LSRpt to 1191 "drop all LSRpt from a particular peers" as well provide means to 1192 limit inbound LSRpts. 1194 12.3. Liveness Detection and Monitoring 1196 Mechanisms defined in this document do not imply any new liveness 1197 detection and monitoring requirements in addition to those already 1198 listed in [RFC5440]". 1200 12.4. Verify Correct Operations 1202 Mechanisms defined in this document do not imply any new operation 1203 verification requirements in addition to those already listed in 1204 [RFC5440] . 1206 12.5. Requirements On Other Protocols 1208 Mechanisms defined in this document do not imply any new requirements 1209 on other protocols. 1211 12.6. Impact On Network Operations 1213 Mechanisms defined in this document do not have any impact on network 1214 operations in addition to those already listed in [RFC5440]. 1216 13. IANA Considerations 1218 This document requests IANA actions to allocate code points for the 1219 protocol elements defined in this document. 1221 13.1. PCEP Messages 1223 IANA created a registry for PCEP messages. Each PCEP message has a 1224 message type value. This document defines a new PCEP message value. 1226 Value Meaning Reference 1227 TBD3 LSRpt [This I-D] 1229 13.2. PCEP Objects 1231 This document defines the following new PCEP Object-classes and 1232 Object-values: 1234 Object-Class Value Name Reference 1235 TBD6 LS Object [This I-D] 1236 Object-Type=1 1237 (LS Node) 1238 Object-Type=2 1239 (LS Link) 1240 Object-Type=3 1241 (LS IPv4 Prefix) 1242 Object-Type=4 1243 (LS IPv6 Prefix) 1245 13.3. LS Object 1247 This document requests that a new sub-registry, named "LS Object 1248 Protocol-ID Field", is created within the "Path Computation Element 1249 Protocol (PCEP) Numbers" registry to manage the Flag field of the LSP 1250 object. New values are to be assigned by Standards Action [RFC8126]. 1252 Value Meaning Reference 1253 0 Reserved [This I-D] 1254 1 IS-IS Level 1 [This I-D] 1255 2 IS-IS Level 2 [This I-D] 1256 3 OSPFv2 [This I-D] 1257 4 Direct [This I-D] 1258 5 Static configuration [This I-D] 1259 6 OSPFv3 [This I-D] 1260 7 BGP-LS [This I-D] 1261 8 PCEP-LS [This I-D] 1262 9 Abstraction [This I-D] 1263 10 Unspecified [This I-D] 1265 Further, this document also requests that a new sub-registry, named 1266 "LS Object Flag Field", is created within the "Path Computation 1267 Element Protocol (PCEP) Numbers" registry to manage the Flag field of 1268 the LSP object.New values are to be assigned by Standards Action 1269 [RFC8126]. Each bit should be tracked with the following qualities: 1271 o Bit number (counting from bit 0 as the most significant bit) 1273 o Capability description 1275 o Defining RFC 1277 The following values are defined in this document: 1279 Bit Description Reference 1280 0-21 Unassigned 1281 22 R (Remove bit) [This I-D] 1282 23 S (Sync bit) [This I-D] 1284 13.4. PCEP-Error Object 1286 IANA is requested to make the following allocation in the "PCEP-ERROR 1287 Object Error Types and Values" registry. 1289 Error-Type Meaning Reference 1290 6 Mandatory Object missing [RFC5440] 1291 Error-Value=TBD4 [This I-D] 1292 (LS object missing) 1294 19 Invalid Operation [RFC8231] 1295 Error-Value=TBD1 [This I-D] 1296 (Attempted LS Report if LS 1297 remote capability was not 1298 advertised) 1300 TBD2 LS Synchronization Error [This I-D] 1301 Error-Value=1 1302 (An error in processing the 1303 LSRpt) 1304 Error-Value=2 1305 (An internal PCC error) 1307 13.5. PCEP TLV Type Indicators 1309 This document defines the following new PCEP TLVs. 1311 Value Meaning Reference 1312 TBD5 LS-CAPABILITY TLV [This I-D] 1313 TBD7 ROUTING-UNIVERSE TLV [This I-D] 1314 TBD15 ROUTE-DISTINGUISHER TLV [This I-D] 1315 TBD8 Local Node Descriptors TLV [This I-D] 1316 TBD9 Remote Node Descriptors TLV [This I-D] 1317 TBD10 Link Descriptors TLV [This I-D] 1318 TBD11 Prefix Descriptors TLV [This I-D] 1319 TBD12 Node Attributes TLV [This I-D] 1320 TBD13 Link Attributes TLV [This I-D] 1321 TBD14 Prefix Attributes TLV [This I-D] 1323 13.6. PCEP-LS Sub-TLV Type Indicators 1325 This document specifies the PCEP-LS Sub-TLVs. IANA is requested to 1326 create an "PCEP-LS Sub-TLV Types" sub-registry in the "PCEP TLV Type 1327 Indicators" for the sub-TLVs carried in the PCEP-LS TLV (Local and 1328 Remote Node Descriptors TLV, Link Descriptors TLV, Prefix Descriptors 1329 TLV, Node Attributes TLV, Link Attributes TLV and Prefix Attributes 1330 TLV. This document defines the following types: 1332 +-----------+---------------------+---------------+-----------------+ 1333 | Sub-TLV | Description | Ref | Value defined | 1334 | | | Sub-TLV | in: | 1335 +-----------+---------------------+---------------+-----------------+ 1336 | 1 | Autonomous System | 512 | [RFC7752] | 1337 | | | | /3.2.1.4 | 1338 | 2 | BGP-LS Identifier | 513 | [RFC7752] | 1339 | | | | /3.2.1.4 | 1340 | 3 | OSPF Area-ID | 514 | [RFC7752] | 1341 | | | | /3.2.1.4 | 1342 | 4 | Router-ID | 515 | [RFC7752] | 1343 | | | | /3.2.1.4 | 1344 | 5 | Multi-Topology-ID | 263 | [RFC7752] | 1345 | | | | /3.2.1.5 | 1346 | 6 | Link Local/Remote | 22/4 | [RFC5307]/1.1 | 1347 | | Identifiers | | | 1348 | 7 | IPv4 interface | 22/6 | [RFC5305]/3.2 | 1349 | | address | | | 1350 | 8 | IPv4 neighbor | 22/8 | [RFC5305]/3.3 | 1351 | | address | | | 1352 | 9 | IPv6 interface | 22/12 | [RFC6119]/4.2 | 1353 | | address | | | 1354 | 10 | IPv6 neighbor | 22/13 | [RFC6119]/4.3 | 1355 | | address | | | 1356 | 11 | OSPF Route Type | 264 | [RFC7752] | 1357 | | | | /3.2.3.1 | 1358 | 12 | IP Reachability | 265 | [RFC7752] | 1359 | | Information | | /3.2.3.2 | 1360 | 13 | Node Flag Bits | 1024 | [RFC7752] | 1361 | | | | /3.3.1.1 | 1362 | 14 | Opaque Node | 1025 | [RFC7752] | 1363 | | Properties | | /3.3.1.5 | 1364 | 15 | Node Name | 1026 | [RFC7752] | 1365 | | | | /3.3.1.3 | 1366 | 16 | IS-IS Area | 1027 | [RFC7752] | 1367 | | Identifier | | /3.3.1.2 | 1368 | 17 | IPv4 Router-ID of | 134/-- | [RFC5305]/4.3 | 1369 | | Local Node | | | 1370 | 18 | IPv6 Router-ID of | 140/-- | [RFC6119]/4.1 | 1371 | | Local Node | | | 1372 | 19 | IPv4 Router-ID of | 134/-- | [RFC5305]/4.3 | 1373 | | Remote Node | | | 1374 | 20 | IPv6 Router-ID of | 140/-- | [RFC6119]/4.1 | 1375 | | Remote Node | | | 1376 | 22 | Administrative | 22/3 | [RFC5305]/3.1 | 1377 | | group (color) | | | 1378 | 23 | Maximum link | 22/9 | [RFC5305]/3.3 | 1379 | | bandwidth | | | 1380 | 24 | Max. reservable | 22/10 | [RFC5305]/3.5 | 1381 | | link bandwidth | | | 1382 | 25 | Unreserved | 22/11 | [RFC5305]/3.6 | 1383 | | bandwidth | | | 1384 | 26 | TE Default Metric | 22/18 | [RFC7752] | 1385 | | | | /3.3.2.3 | 1386 | 27 | Link Protection | 22/20 | [RFC5307]/1.2 | 1387 | | Type | | | 1388 | 28 | MPLS Protocol Mask | 1094 | [RFC7752] | 1389 | | | | /3.3.2.2 | 1390 | 29 | IGP Metric | 1095 | [RFC7752] | 1391 | | | | /3.3.2.4 | 1392 | 30 | Shared Risk Link | 1096 | [RFC7752] | 1393 | | Group | | /3.3.2.5 | 1394 | 31 | Opaque link | 1097 | [RFC7752] | 1395 | | attributes | | /3.3.2.6 | 1396 | 32 | Link Name attribute | 1098 | [RFC7752] | 1397 | | | | /3.3.2.7 | 1398 | 33 | Unidirectional | 22/33 | [RFC7810]/4.1 | 1399 | | Link Delay | | | 1400 | 34 | Min/Max | 22/34 | [RFC7810]/4.2 | 1401 | | Unidirectional Link | | | 1402 | | Delay | | | 1403 | 35 | Unidirectional | 22/35 | [RFC7810]/4.3 | 1404 | | Delay Variation | | | 1405 | 36 | Unidirectional | 22/36 | [RFC7810]/4.4 | 1406 | | Link Loss | | | 1407 | 37 | Unidirectional | 22/37 | [RFC7810]/4.5 | 1408 | | Residual Bandwidth | | | 1409 | 38 | Unidirectional | 22/38 | [RFC7810]/4.6 | 1410 | | Available Bandwidth | | | 1411 | 39 | Unidirectional | 22/39 | [RFC7810]/4.7 | 1412 | | Bandwidth | | | 1413 | | Utilization | | | 1414 | 40 | Extended Admin | 22/14 | [RFC7308]/2.1 | 1415 | | Group (EAG) | | | 1416 | 41 | IGP Flags | 1152 | [RFC7752] | 1417 | | | | /3.3.3.1 | 1418 | 42 | Route Tag | 1153 | [RFC7752] | 1419 | | | | /3.3.3.2 | 1420 | 43 | Extended Tag | 1154 | [RFC7752] | 1421 | | | | /3.3.3.3 | 1422 | 44 | Prefix Metric | 1155 | [RFC7752] | 1423 | | | | /3.3.3.4 | 1424 | 45 | OSPF Forwarding | 1156 | [RFC7752] | 1425 | | Address | | /3.3.3.5 | 1426 | 46 | Opaque Prefix | 1157 | [RFC7752] | 1427 | | Attribute | | /3.3.3.6 | 1428 +-----------+---------------------+---------------+-----------------+ 1429 New values are to be assigned by Standards Action [RFC8126]. 1431 14. TLV/Sub-TLV Code Points Summary 1433 This section contains the global table of all TLVs/Sub-TLVs in LS 1434 object defined in this document. 1436 +-----------+---------------------+---------------+-----------------+ 1437 | TLV | Description | Ref TLV | Value defined | 1438 | | | | in: | 1439 +-----------+---------------------+---------------+-----------------+ 1440 | TBD7 | Routing Universe | -- | Sec 9.2.1 | 1441 | TBD15 | Route | -- | Sec 9.2.2 | 1442 | | Distinguisher | | | 1443 | * | Virtual Network | -- | [leedhody-pce- | 1444 | | | | vn-association] | 1445 | TBD8 | Local Node | 256 | [RFC7752] | 1446 | | Descriptors | | /3.2.1.2 | 1447 | TBD9 | Remote Node | 257 | [RFC7752] | 1448 | | Descriptors | | /3.2.1.3 | 1449 | TBD10 | Link Descriptors | -- | Sec 9.2.8 | 1450 | TBD11 | Prefix Descriptors | -- | Sec 9.2.9 | 1451 | TBD12 | Node Attributes | -- | Sec 9.2.10.1 | 1452 | TBD13 | Link Attributes | -- | Sec 9.2.10.2 | 1453 | TBD14 | Prefix Attributes | -- | Sec 9.2.10.3 | 1454 +-----------+---------------------+---------------+-----------------+ 1456 * this TLV is defined in a different PCEP document 1458 TLV Table 1460 Refer Section 13.6 for the table of Sub-TLVs. 1462 15. Implementation Status 1464 The PCEP-LS protocol extension as described in this I-D were 1465 implemented and tested for a variety of applications. Apart from the 1466 below implementation, there exist other experimental implementations 1467 done for optical networks. 1469 15.1. Hierarchical Transport PCE controllers 1471 The PCEP-LS has been implemented as part of IETF97 Hackathon and 1472 Bits-N-Bites demonstration. The use-case demonstrated was DCI use- 1473 case of ACTN architecture in which to show the following scenarios: 1475 - connectivity services on the ACTN based recursive hierarchical 1476 SDN/PCE platform that has the three tier level SDN controllers 1477 (two-tier level MDSC and PNC) on the top of the PTN systems 1478 managed by EMS. 1480 - Integration test of two tier-level MDSC: The SBI of the low 1481 level MDSC is the YANG based Korean national standards and the one 1482 of the high level MDSC the PCEP-LS based ACTN protocols. 1484 - Performance test of three types of SDN controller based recovery 1485 schemes including protection, reactive and proactive restoration. 1486 PCEP-LS protocol was used to demonstrate quick report of failed 1487 network components. 1489 15.2. ONOS-based Controller (MDSC and PNC) 1491 Huawei (PNC, MDSC) and SKT (MDSC) implemented PCEP-LS during 1492 Hackathon and IETF97 Bits-N-Bites demonstration. The demonstration 1493 was ONOS-based ACTN architecture in which to show the following 1494 capabilities: 1496 Both packet PNC and optical PNC (with optical PCEP-LS extension) 1497 implemented PCEP-LS on its SBI and well as its NBI (towards MDSC). 1499 SKT orchestrator (acting as MDSC) also supported PCEP-LS (as well 1500 as RestConf) towards packet and optical PNCs on its SBI. 1502 Further description can be found at and the code at 1503 . 1505 16. Acknowledgments 1507 This document borrows some of the structure and text from the 1508 [RFC7752]. 1510 Thanks to Eric Wu, Venugopal Kondreddy, Mahendra Singh Negi, 1511 Avantika, and Zhengbin Li for the reviews. 1513 Thanks to Ramon Casellas for his comments and suggestions based on 1514 his implementation experience. 1516 17. References 1518 17.1. Normative References 1520 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 1521 Requirement Levels", BCP 14, RFC 2119, 1522 DOI 10.17487/RFC2119, March 1997, 1523 . 1525 [RFC5305] Li, T. and H. Smit, "IS-IS Extensions for Traffic 1526 Engineering", RFC 5305, DOI 10.17487/RFC5305, October 1527 2008, . 1529 [RFC5307] Kompella, K., Ed. and Y. Rekhter, Ed., "IS-IS Extensions 1530 in Support of Generalized Multi-Protocol Label Switching 1531 (GMPLS)", RFC 5307, DOI 10.17487/RFC5307, October 2008, 1532 . 1534 [RFC5440] Vasseur, JP., Ed. and JL. Le Roux, Ed., "Path Computation 1535 Element (PCE) Communication Protocol (PCEP)", RFC 5440, 1536 DOI 10.17487/RFC5440, March 2009, 1537 . 1539 [RFC6119] Harrison, J., Berger, J., and M. Bartlett, "IPv6 Traffic 1540 Engineering in IS-IS", RFC 6119, DOI 10.17487/RFC6119, 1541 February 2011, . 1543 [RFC7752] Gredler, H., Ed., Medved, J., Previdi, S., Farrel, A., and 1544 S. Ray, "North-Bound Distribution of Link-State and 1545 Traffic Engineering (TE) Information Using BGP", RFC 7752, 1546 DOI 10.17487/RFC7752, March 2016, 1547 . 1549 [RFC7810] Previdi, S., Ed., Giacalone, S., Ward, D., Drake, J., and 1550 Q. Wu, "IS-IS Traffic Engineering (TE) Metric Extensions", 1551 RFC 7810, DOI 10.17487/RFC7810, May 2016, 1552 . 1554 17.2. Informative References 1556 [RFC3630] Katz, D., Kompella, K., and D. Yeung, "Traffic Engineering 1557 (TE) Extensions to OSPF Version 2", RFC 3630, 1558 DOI 10.17487/RFC3630, September 2003, 1559 . 1561 [RFC4203] Kompella, K., Ed. and Y. Rekhter, Ed., "OSPF Extensions in 1562 Support of Generalized Multi-Protocol Label Switching 1563 (GMPLS)", RFC 4203, DOI 10.17487/RFC4203, October 2005, 1564 . 1566 [RFC4364] Rosen, E. and Y. Rekhter, "BGP/MPLS IP Virtual Private 1567 Networks (VPNs)", RFC 4364, DOI 10.17487/RFC4364, February 1568 2006, . 1570 [RFC4655] Farrel, A., Vasseur, J., and J. Ash, "A Path Computation 1571 Element (PCE)-Based Architecture", RFC 4655, 1572 DOI 10.17487/RFC4655, August 2006, 1573 . 1575 [RFC5120] Przygienda, T., Shen, N., and N. Sheth, "M-ISIS: Multi 1576 Topology (MT) Routing in Intermediate System to 1577 Intermediate Systems (IS-ISs)", RFC 5120, 1578 DOI 10.17487/RFC5120, February 2008, 1579 . 1581 [RFC5316] Chen, M., Zhang, R., and X. Duan, "ISIS Extensions in 1582 Support of Inter-Autonomous System (AS) MPLS and GMPLS 1583 Traffic Engineering", RFC 5316, DOI 10.17487/RFC5316, 1584 December 2008, . 1586 [RFC5392] Chen, M., Zhang, R., and X. Duan, "OSPF Extensions in 1587 Support of Inter-Autonomous System (AS) MPLS and GMPLS 1588 Traffic Engineering", RFC 5392, DOI 10.17487/RFC5392, 1589 January 2009, . 1591 [RFC6549] Lindem, A., Roy, A., and S. Mirtorabi, "OSPFv2 Multi- 1592 Instance Extensions", RFC 6549, DOI 10.17487/RFC6549, 1593 March 2012, . 1595 [RFC6805] King, D., Ed. and A. Farrel, Ed., "The Application of the 1596 Path Computation Element Architecture to the Determination 1597 of a Sequence of Domains in MPLS and GMPLS", RFC 6805, 1598 DOI 10.17487/RFC6805, November 2012, 1599 . 1601 [RFC8126] Cotton, M., Leiba, B., and T. Narten, "Guidelines for 1602 Writing an IANA Considerations Section in RFCs", BCP 26, 1603 RFC 8126, DOI 10.17487/RFC8126, June 2017, 1604 . 1606 [RFC8202] Ginsberg, L., Previdi, S., and W. Henderickx, "IS-IS 1607 Multi-Instance", RFC 8202, DOI 10.17487/RFC8202, June 1608 2017, . 1610 [RFC8231] Crabbe, E., Minei, I., Medved, J., and R. Varga, "Path 1611 Computation Element Communication Protocol (PCEP) 1612 Extensions for Stateful PCE", RFC 8231, 1613 DOI 10.17487/RFC8231, September 2017, 1614 . 1616 [RFC8281] Crabbe, E., Minei, I., Sivabalan, S., and R. Varga, "Path 1617 Computation Element Communication Protocol (PCEP) 1618 Extensions for PCE-Initiated LSP Setup in a Stateful PCE 1619 Model", RFC 8281, DOI 10.17487/RFC8281, December 2017, 1620 . 1622 [RFC8253] Lopez, D., Gonzalez de Dios, O., Wu, Q., and D. Dhody, 1623 "PCEPS: Usage of TLS to Provide a Secure Transport for the 1624 Path Computation Element Communication Protocol (PCEP)", 1625 RFC 8253, DOI 10.17487/RFC8253, October 2017, 1626 . 1628 [I-D.ietf-pce-pcep-yang] 1629 Dhody, D., Hardwick, J., Beeram, V., and J. Tantsura, "A 1630 YANG Data Model for Path Computation Element 1631 Communications Protocol (PCEP)", draft-ietf-pce-pcep- 1632 yang-05 (work in progress), June 2017. 1634 [I-D.ietf-pce-applicability-actn] 1635 Dhody, D., Lee, Y., and D. Ceccarelli, "Applicability of 1636 Path Computation Element (PCE) for Abstraction and Control 1637 of TE Networks (ACTN)", draft-ietf-pce-applicability- 1638 actn-02 (work in progress), October 2017. 1640 [I-D.ietf-teas-actn-framework] 1641 Ceccarelli, D. and Y. Lee, "Framework for Abstraction and 1642 Control of Traffic Engineered Networks", draft-ietf-teas- 1643 actn-framework-11 (work in progress), October 2017. 1645 [I-D.ietf-teas-actn-requirements] 1646 Lee, Y., Dhody, D., Belotti, S., Pithewan, K., Ceccarelli, 1647 D., Miyasaka, T., Shin, J., and K. Lee, "Requirements for 1648 Abstraction and Control of TE Networks", draft-ietf-teas- 1649 actn-requirements-07 (work in progress), October 2017. 1651 [I-D.kondreddy-pce-pcep-ls-sync-optimizations] 1652 Kondreddy, V. and M. Negi, "Optimizations of PCEP Link- 1653 State(LS) Synchronization Procedures", draft-kondreddy- 1654 pce-pcep-ls-sync-optimizations-00 (work in progress), 1655 October 2015. 1657 [I-D.leedhody-pce-vn-association] 1658 Lee, Y., Dhody, D., Zhang, X., and D. Ceccarelli, "PCEP 1659 Extensions for Establishing Relationships Between Sets of 1660 LSPs and Virtual Networks", draft-leedhody-pce-vn- 1661 association-03 (work in progress), September 2017. 1663 [ONOS-PCEP] 1664 "Support for PCEP in ONOS", 1665 . 1667 [ONOS-PCEP-GITHUB] 1668 "Github for PCEP code in ONOS", 1669 . 1672 Appendix A. Relevant OSPF TLV and sub-TLV 1674 This section list the relevant TLVs and sub-TLVs defined for OSPF. 1676 +-----------+---------------------+---------------+-----------------+ 1677 | Sub-TLV | Description | OSPF-TE | Value defined | 1678 | | | Sub-TLV | in: | 1679 +-----------+---------------------+---------------+-----------------+ 1680 | 6 | Link Local/Remote | 11 | [RFC4203]/1.1 | 1681 | | Identifiers | | | 1682 | 7 | IPv4 interface | 3 | [RFC3630]/2.5.3 | 1683 | | address | | | 1684 | 8 | IPv4 neighbor | 4 | [RFC3630]/2.5.4 | 1685 | | address | | | 1686 | 9 | IPv6 interface | 19 | [RFC5329]/4.3 | 1687 | | address | | | 1688 | 10 | IPv6 neighbor | 20 | [RFC5329]/4.4 | 1689 | | address | | | 1690 | 17 | IPv4 Router-ID of | 1 | [RFC3630]/2.4.1 | 1691 | | Local Node | | | 1692 | 18 | IPv6 Router-ID of | 3 | [RFC5329]/3 | 1693 | | Local Node | | | 1694 | 19 | IPv4 Router-ID of | 1 | [RFC3630]/2.4.1 | 1695 | | Remote Node | | | 1696 | 20 | IPv6 Router-ID of | 3 | [RFC5329]/3 | 1697 | | Remote Node | | | 1698 | 22 | Administrative | 9 | [RFC3630]/2.5.9 | 1699 | | group (color) | | | 1700 | 23 | Maximum link | 6 | [RFC3630]/2.5.6 | 1701 | | bandwidth | | | 1702 | 24 | Max. reservable | 7 | [RFC3630]/2.5.7 | 1703 | | link bandwidth | | | 1704 | 25 | Unreserved | 8 | [RFC3630]/2.5.8 | 1705 | | bandwidth | | | 1706 | 27 | Link Protection | 14 | [RFC4203]/1.2 | 1707 | | Type | | | 1708 | 30 | Shared Risk Link | 16 | [RFC4203]/1.3 | 1709 | | Group | | | 1710 | 33 | Unidirectional | 27 | [RFC7471]/4.1 | 1711 | | Link Delay | | | 1712 | 34 | Min/Max | 28 | [RFC7471]/4.2 | 1713 | | Unidirectional Link | | | 1714 | | Delay | | | 1715 | 35 | Unidirectional | 29 | [RFC7471]/4.3 | 1716 | | Delay Variation | | | 1717 | 36 | Unidirectional | 30 | [RFC7471]/4.4 | 1718 | | Link Loss | | | 1719 | 37 | Unidirectional | 31 | [RFC7471]/4.5 | 1720 | | Residual Bandwidth | | | 1721 | 38 | Unidirectional | 32 | [RFC7471]/4.6 | 1722 | | Available Bandwidth | | | 1723 | 39 | Unidirectional | 33 | [RFC7471]/4.7 | 1724 | | Bandwidth | | | 1725 | | Utilization | | | 1726 | 40 | Extended Admin | 26 | [RFC7308]/2.1 | 1727 | | Group (EAG) | | | 1728 +-----------+---------------------+---------------+-----------------+ 1730 Appendix B. Examples 1732 These examples are for illustration purposes only to show how the new 1733 PCEP-LS message could be encoded. They are not meant to be an 1734 exhaustive list of all possible use cases and combinations. 1736 B.1. All Nodes 1738 Each node (PCC) in the network chooses to provide its own local node 1739 and link information, and in this way PCE can build the full link 1740 state and TE information. 1742 +--------------------+ +--------------------+ 1743 | | | | 1744 | RTA |10.1.1.1 | RTB | 1745 | 1.1.1.1 |--------------------| 2.2.2.2 | 1746 | Area 0 | 10.1.1.2| Area 0 | 1747 | | | | 1748 +--------------------+ +--------------------+ 1749 RTA 1750 --- 1751 LS Node 1752 TLV - Local Node Descriptors 1753 Sub-TLV - 3: OSPF Area-ID: 0.0.0.0 1754 Sub-TLV - 4: Router-ID: 1.1.1.1 1755 TLV - Node Attributes TLV 1756 Sub-TLV(s) 1758 LS Link 1759 TLV - Local Node Descriptors 1760 Sub-TLV - 3: OSPF Area-ID: 0.0.0.0 1761 Sub-TLV - 4: Router-ID: 1.1.1.1 1762 TLV - Remote Node Descriptors 1763 Sub-TLV - 3: OSPF Area-ID: 0.0.0.0 1764 Sub-TLV - 4: Router-ID: 2.2.2.2 1765 TLV - Link Descriptors 1766 Sub-TLV - 7: IPv4 interface: 10.1.1.1 1767 Sub-TLV - 8: IPv4 neighbor: 10.1.1.2 1768 TLV - Link Attributes TLV 1769 Sub-TLV(s) 1771 RTB 1772 --- 1773 LS Node 1774 TLV - Local Node Descriptors 1775 Sub-TLV - 3: OSPF Area-ID: 0.0.0.0 1776 Sub-TLV - 4: Router-ID: 2.2.2.2 1777 TLV - Node Attributes TLV 1778 Sub-TLV(s) 1780 LS Link 1781 TLV - Local Node Descriptors 1782 Sub-TLV - 3: OSPF Area-ID: 0.0.0.0 1783 Sub-TLV - 4: Router-ID: 2.2.2.2 1784 TLV - Remote Node Descriptors 1785 Sub-TLV - 3: OSPF Area-ID: 0.0.0.0 1786 Sub-TLV - 4: Router-ID: 1.1.1.1 1787 TLV - Link Descriptors 1788 Sub-TLV - 7: IPv4 interface: 10.1.1.2 1789 Sub-TLV - 8: IPv4 neighbor: 10.1.1.1 1790 TLV - Link Attributes TLV 1791 Sub-TLV(s) 1793 B.2. Designated Node 1795 A designated node(s) in the network will provide its own local node 1796 as well as all learned remote information, and in this way PCE can 1797 build the full link state and TE information. 1799 As described in Appendix B.1, the same LS Node and Link objects will 1800 be generated with a difference that it would be a designated router 1801 say RTA that generate all this information. 1803 B.3. Between PCEs 1805 As per Hierarchical-PCE [RFC6805], Parent PCE builds an abstract 1806 domain topology map with each domain as an abstract node and inter- 1807 domain links as an abstract link. Each child PCE may provide this 1808 information to the parent PCE. Considering the example in figure 1 1809 of [RFC6805], following LS object will be generated: 1811 PCE1 1812 ---- 1813 LS Node 1814 TLV - Local Node Descriptors 1815 Sub-TLV - 1: Autonomous System: 100 (Domain 1) 1816 Sub-TLV - 4: Router-ID: 11.11.11.11 (abstract) 1818 LS Link 1819 TLV - Local Node Descriptors 1820 Sub-TLV - 1: Autonomous System: 100 1821 Sub-TLV - 4: Router-ID: 11.11.11.11 (abstract) 1822 TLV - Remote Node Descriptors 1823 Sub-TLV - 1: Autonomous System: 200 (Domain 2) 1824 Sub-TLV - 4: Router-ID: 22.22.22.22 (abstract) 1825 TLV - Link Descriptors 1826 Sub-TLV - 7: IPv4 interface: 11.1.1.1 1827 Sub-TLV - 8: IPv4 neighbor: 11.1.1.2 1828 TLV - Link Attributes TLV 1829 Sub-TLV(s) 1831 LS Link 1832 TLV - Local Node Descriptors 1833 Sub-TLV - 1: Autonomous System: 100 1834 Sub-TLV - 4: Router-ID: 11.11.11.11 (abstract) 1835 TLV - Remote Node Descriptors 1836 Sub-TLV - 1: Autonomous System: 200 1837 Sub-TLV - 4: Router-ID: 22.22.22.22 (abstract) 1838 TLV - Link Descriptors 1839 Sub-TLV - 7: IPv4 interface: 12.1.1.1 1840 Sub-TLV - 8: IPv4 neighbor: 12.1.1.2 1841 TLV - Link Attributes TLV 1842 Sub-TLV(s) 1844 LS Link 1845 TLV - Local Node Descriptors 1846 Sub-TLV - 1: Autonomous System: 100 1847 Sub-TLV - 4: Router-ID: 11.11.11.11 (abstract) 1848 TLV - Remote Node Descriptors 1849 Sub-TLV - 1: Autonomous System: 400 (Domain 4) 1850 Sub-TLV - 4: Router-ID: 44.44.44.44 (abstract) 1851 TLV - Link Descriptors 1852 Sub-TLV - 7: IPv4 interface: 13.1.1.1 1853 Sub-TLV - 8: IPv4 neighbor: 13.1.1.2 1854 TLV - Link Attributes TLV 1855 Sub-TLV(s) 1857 * similar information will be generated by other PCE 1858 to help form the abstract domain topology. 1860 Further the exact border nodes and abstract internal path between the 1861 border nodes may also be transported to the Parent PCE to enable ACTN 1862 as described in [I-D.ietf-pce-applicability-actn] using the similar 1863 LS node and link objects encodings. 1865 Appendix C. Contributor Addresses 1867 Udayasree Palle 1868 Huawei Technologies 1869 Divyashree Techno Park, Whitefield 1870 Bangalore, Karnataka 560066 1871 India 1873 EMail: udayasreereddy@gmail.com 1875 Sergio Belotti 1876 Alcatel-Lucent 1877 Italy 1879 EMail: sergio.belotti@alcatel-lucent.com 1881 Veerendranatha Reddy Vallem 1882 Huawei Technologies 1883 Divyashree Techno Park, Whitefield 1884 Bangalore, Karnataka 560066 1885 India 1887 Email: veerendranatharv@huawei.com 1889 Satish Karunanithi 1890 Huawei Technologies 1891 Divyashree Techno Park, Whitefield 1892 Bangalore, Karnataka 560066 1893 India 1895 Email: satishk@huawei.com 1897 Authors' Addresses 1899 Dhruv Dhody 1900 Huawei Technologies 1901 Divyashree Techno Park, Whitefield 1902 Bangalore, Karnataka 560066 1903 India 1905 EMail: dhruv.ietf@gmail.com 1906 Young Lee 1907 Huawei Technologies 1908 5340 Legacy Drive, Building 3 1909 Plano, TX 75023 1910 USA 1912 EMail: leeyoung@huawei.com 1914 Daniele Ceccarelli 1915 Ericsson 1916 Torshamnsgatan,48 1917 Stockholm 1918 Sweden 1920 EMail: daniele.ceccarelli@ericsson.com