idnits 2.17.1 draft-lee-pce-wson-impairments-07.txt: Checking boilerplate required by RFC 5378 and the IETF Trust (see https://trustee.ietf.org/license-info): ---------------------------------------------------------------------------- No issues found here. Checking nits according to https://www.ietf.org/id-info/1id-guidelines.txt: ---------------------------------------------------------------------------- No issues found here. Checking nits according to https://www.ietf.org/id-info/checklist : ---------------------------------------------------------------------------- ** There are 4 instances of too long lines in the document, the longest one being 17 characters in excess of 72. Miscellaneous warnings: ---------------------------------------------------------------------------- == The copyright year in the IETF Trust and authors Copyright Line does not match the current year -- The document date (June 26, 2018) is 2124 days in the past. Is this intentional? Checking references for intended status: Proposed Standard ---------------------------------------------------------------------------- (See RFCs 3967 and 4897 for information about using normative references to lower-maturity documents in RFCs) == Missing Reference: 'PCEP-MIB' is mentioned on line 614, but not defined == Missing Reference: 'PCEP' is mentioned on line 645, but not defined == Unused Reference: 'RFC2119' is defined on line 659, but no explicit reference was found in the text == Unused Reference: 'RFC3471' is defined on line 662, but no explicit reference was found in the text == Unused Reference: 'RFC3473' is defined on line 666, but no explicit reference was found in the text Summary: 1 error (**), 0 flaws (~~), 6 warnings (==), 1 comment (--). Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 1 Network Working Group Y. Lee 2 Internet Draft Huawei 3 Intended status: Standard Track 4 Expires: December 2018 G. Bernstein 5 Grotto Networking 7 Jonas Martensson 8 Acreo 10 T. Takeda 11 NTT 13 T. Tsuritani 14 KDDI 16 June 26, 2018 18 PCEP Extensions for WSON Impairments 20 draft-lee-pce-wson-impairments-07 22 Abstract 24 As an optical signal progresses along its path it may be altered by 25 the various physical processes in the optical fibers and devices it 26 encounters. When such alterations result in signal degradation, 27 these processes are usually referred to as "impairments". These 28 physical characteristics may be important constraints to consider in 29 path computation process in wavelength switched optical networks. 31 This document provides PCEP extensions to support Impairment Aware 32 Routing and Wavelength Assignment (IA-RWA) in wavelength switched 33 optical networks. 35 Status of this Memo 37 This Internet-Draft is submitted to IETF in full conformance with 38 the provisions of BCP 78 and BCP 79. 40 Internet-Drafts are working documents of the Internet Engineering 41 Task Force (IETF), its areas, and its working groups. Note that 42 other groups may also distribute working documents as Internet- 43 Drafts. 45 Internet-Drafts are draft documents valid for a maximum of six 46 months and may be updated, replaced, or obsoleted by other documents 47 at any time. It is inappropriate to use Internet-Drafts as 48 reference material or to cite them other than as "work in progress." 50 The list of current Internet-Drafts can be accessed at 51 http://www.ietf.org/ietf/1id-abstracts.txt 53 The list of Internet-Draft Shadow Directories can be accessed at 54 http://www.ietf.org/shadow.html 56 This Internet-Draft will expire on December 26, 2018. 58 Copyright Notice 60 Copyright (c) 2018 IETF Trust and the persons identified as the 61 document authors. All rights reserved. 63 This document is subject to BCP 78 and the IETF Trust's Legal 64 Provisions Relating to IETF Documents 65 (http://trustee.ietf.org/license-info) in effect on the date of 66 publication of this document. Please review these documents 67 carefully, as they describe your rights and restrictions with 68 respect to this document. Code Components extracted from this 69 document must include Simplified BSD License text as described in 70 Section 4.e of the Trust Legal Provisions and are provided without 71 warranty as described in the Simplified BSD License. 73 Conventions used in this document 75 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 76 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this 77 document are to be interpreted as described in RFC-2119 0. 79 Table of Contents 81 1. Introduction...................................................3 82 1.1. WSON RWA Processes (no impairments).......................5 83 1.2. WSON IA-RWA Processes.....................................6 84 2. WSON PCE Architectures and Requirements........................8 85 2.1. RWA PCC to PCE Interface..................................9 86 2.1.1. A new RWA path request...............................9 87 2.1.1.1. Signal Quality Measure TLV.....................10 88 2.1.2. A new RWA path reply................................12 89 2.1.2.1. Signal Quality Measure TLV.....................12 90 2.2. RWA-PCE to IV-PCE Interface..............................14 91 2.2.1. A new impairment-validated (IV) path request........15 92 2.2.2. A new impairment-validated (IV) path reply..........15 93 3. Manageability Considerations..................................15 94 3.1. Control of Function and Policy...........................15 95 3.2. Information and Data Models, e.g. MIB module.............16 96 3.3. Liveness Detection and Monitoring........................16 97 3.4. Verifying Correct Operation..............................16 98 3.5. Requirements on Other Protocols and Functional Components16 99 3.6. Impact on Network Operation..............................17 100 4. Security Considerations.......................................17 101 5. IANA Considerations...........................................17 102 6. References....................................................17 103 6.1. Normative References.....................................17 104 6.2. Informative References...................................18 105 Authors' Addresses...............................................18 106 7. Acknowledgments...............................................19 108 1. Introduction 110 [RFC4655] defines the PCE based architecture and explains how a Path 111 Computation Element (PCE) may compute Label Switched Paths (LSP) in 112 Multiprotocol Label Switching Traffic Engineering (MPLS-TE) and 113 Generalized MPLS (GMPLS) networks at the request of Path Computation 114 Clients (PCCs). A PCC is shown to be any network component that 115 makes such a request and may be for instance an Optical Switching 116 Element within a Wavelength Division Multiplexing (WDM) network. 117 The PCE, itself, can be located anywhere within the network, and may 118 be within an optical switching element, a Network Management System 119 (NMS) or Operational Support System (OSS), or may be an independent 120 network server. 122 The PCE communication Protocol (PCEP) is the communication protocol 123 used between PCC and PCE, and may also be used between cooperating 124 PCEs. [RFC4657] sets out the common protocol requirements for PCEP. 125 Additional application-specific requirements for PCEP are deferred 126 to separate documents. 128 This document provides a set of application-specific PCEP 129 requirements for support of path computation in Wavelength Switched 130 Optical Networks (WSON) with impairments. WSON refers to WDM based 131 optical networks in which switching is performed selectively based 132 on the wavelength of an optical signal. 134 The path in WSON is referred to as a lightpath. A lightpath may 135 span multiple fiber links and the path should be assigned a 136 wavelength for each link. A transparent optical network is made up 137 of optical devices that can switch but not convert from one 138 wavelength to another. In a transparent optical network, a lightpath 139 operates on the same wavelength across all fiber links that it 140 traverses. In such case, the lightpath is said to satisfy the 141 wavelength-continuity constraint. Two lightpaths that share a common 142 fiber link can not be assigned the same wavelength. To do otherwise 143 would result in both signals interfering with each other. Note that 144 advanced additional multiplexing techniques such as polarization 145 based multiplexing are not addressed in this document since the 146 physical layer aspects are not currently standardized. Therefore, 147 assigning the proper wavelength on a lightpath is an essential 148 requirement in the optical path computation process. 150 When a switching node has the ability to perform wavelength 151 conversion the wavelength-continuity constraint can be relaxed, and 152 a lightpath may use different wavelengths on different links along 153 its route from origin to destination. It is, however, to be noted 154 that wavelength converters may be limited due to their relatively 155 high cost, while the number of WDM channels that can be supported in 156 a fiber is also limited. As a WSON can be composed of network nodes 157 that cannot perform wavelength conversion, nodes with limited 158 wavelength conversion, and nodes with full wavelength conversion 159 abilities, wavelength assignment is an additional routing constraint 160 to be considered in all lightpath computation. 162 One of the most basic questions in communications is whether one can 163 successfully transmit information from a transmitter to a receiver 164 within a prescribed error tolerance, usually specified as a maximum 165 permissible bit error ratio (BER). This generally depends on the 166 nature of the signal transmitted between the sender and receiver and 167 the nature of the communications channel between the sender and 168 receiver. The optical path utilized (along with the wavelength) 169 determines the communications channel. 171 The optical impairments incurred by the signal along the fiber and 172 at each optical network element along the path determine whether the 173 BER performance or any other measure of signal quality can be met 174 for this particular signal on this particular path. Given the 175 existing standards covering optical characteristics (impairments) 176 and the knowledge of how the impact of impairments may be estimated 177 along a path, [RFC6566] provides a framework for impairment aware 178 path computation and establishment utilizing GMPLS protocols and the 179 PCE architecture. 181 Some transparent optical subnetworks are designed such that over any 182 path the degradation to an optical signal due to impairments never 183 exceeds prescribed bounds. This may be due to the limited geographic 184 extent of the network, the network topology, and/or the quality of 185 the fiber and devices employed. In such networks the path selection 186 problem reduces to determining a continuous wavelength from source 187 to destination (the Routing and Wavelength Assignment problem). 188 These networks are discussed in [RFC6163]. In other optical 189 networks, impairments are important and the path selection process 190 must be impairment-aware. 192 In this document we first review the processes for routing and 193 wavelength assignment (RWA) used when wavelength continuity 194 constraints are present. We then review the processes for optical 195 impairment aware RWA (IA-RWA). Based on selected process models we 196 then specify requirements for PCEP to support IA-RWA. Note that 197 requirements for PCEP to support RWA are specified in a separate 198 document [RFC7449]. 200 The remainder of this document uses terminology from [RFC4655]. 202 1.1. WSON RWA Processes (no impairments) 204 In [RFC6163] three alternative process architectures were given for 205 performing routing and wavelength assignment. These are shown 206 schematically in Figure 1. 208 +-------------------+ 209 | +-------+ +--+ | +-------+ +--+ +-------+ +---+ 210 | |Routing| |WA| | |Routing|--->|WA| |Routing|--->|DWA| 211 | +-------+ +--+ | +-------+ +--+ +-------+ +---+ 212 | Combined | Separate Processes Separate Processes 213 | Processes | WA performed in a 214 +-------------------+ Distributed manner 215 (a) (b) (c) 217 Figure 1 RWA process alternatives. 219 Detail description of each alternative can be found in [RFC6163]. 221 1.2. WSON IA-RWA Processes 223 In [RFC6566] impairments were addressed by adding an "impairment 224 validation" (IV) process. For approximate impairment validation 225 three process alternatives were given in [RFC6566] and are shown in 226 Figure 2. Since there are many possible alternative combinations, 227 these are just three examples. Please note that the requirements for 228 all possible architectures can be reduced to the cases in Figure 3 229 in section 2. 231 +-----------------------------------+ 232 | +--+ +-------+ +--+ | 233 | |IV| |Routing| |WA| | 234 | +--+ +-------+ +--+ | 235 | | 236 | Combined Processes | 237 +-----------------------------------+ 238 (a) 240 +--------------+ +----------------------+ 241 | +----------+ | | +-------+ +--+ | 242 | | IV | | | |Routing| |WA| | 243 | |candidates| |----->| +-------+ +--+ | 244 | +----------+ | | Combined Processes | 245 +--------------+ +----------------------+ 246 (b) 248 +-----------+ +----------------------+ 249 | +-------+ | | +--+ +--+ | 250 | |Routing| |------->| |WA| |IV| | 251 | +-------+ | | +--+ +--+ | 252 +-----------+ | Distributed Processes| 253 +----------------------+ 254 (c) 255 Figure 2 Process flows for the three main approximate impairment 256 architectural alternatives. 258 These alternatives have the following properties and impact on PCEP 259 requirements in this document. 261 1. Combined IV and RWA Process - Here the processes of impairment 262 validation, routing and wavelength assignment are aggregated into 263 a single PCE. The requirements for PCC-PCE interaction with such 264 a combined IV-RWA process PCE is addressed in this document. 266 2. IV-Candidates + RWA Process - As explained in [RFC6566] 267 separating the impairment validation process from the RWA process 268 maybe necessary to deal with impairment sharing constraints. In 269 this architecture one PCE computes impairment candidates and 270 another PCE uses this information while performing RWA. The 271 requirements for PCE-to-PCE interaction of this architecture will 272 be addressed in this document. 274 3. Routing + Distributed WA and IV - Here a standard path 275 computation (unaware of detailed wavelength availability or 276 optical impairments) takes place, then wavelength assignment and 277 impairment validation is performed along this path in a 278 distributed manner via signaling (RSVP-TE). This alternative 279 should be covered by existing or emerging GMPLS PCEP extensions 280 and does not present new WSON specific requirements. 282 2. WSON PCE Architectures and Requirements 284 In the previous section we reviewed various process architectures 285 for implementing RWA with and without regard for optical impairment. 286 In Figure 3 we reduce these alternatives to two PCE based 287 implementations. As specified in [RFC6566], the PCE in Figure 3(a) 288 should be given the necessary information for RWA and impairment 289 validation, including WSON topology, link wavelength utilization as 290 well as impairment information such as the adjustment range of 291 tunable parameters, etc. Similarly, RWA-PCE should be equipped with 292 all the information other than impairment-related ones which is a 293 necessity for IV-PCE. 295 In Figure 3(a) we show the three processes of routing, wavelength 296 assignment and impairment validation accessed via a single PCE. The 297 implementation details of the interactions of the processes are not 298 subject to standardization; this document concernsonly the PCC to 299 PCE communications. 301 In Figure 3(b) the impairment validation process is implemented in a 302 separate PCE. Here the RWA-PCE acts as a coordinator and the PCC to 303 RWA-PCE interface will be the same as in Figure 3(a), however in 304 this case we have additional requirements for the RWA-PCE to IV-PCE 305 interface. 307 +-----------------------------------+ 308 +-----+ | +--+ +-------+ +--+ | 309 | | | |IV| |Routing| |WA| | 310 | PCC |<----->| +--+ +-------+ +--+ | 311 | | | | 312 +-----+ | PCE | 313 +-----------------------------------+ 315 (a) 317 +----------------------+ +--------------+ 318 +-----+ | +-------+ +--+ | | | 319 | | | |Routing| |WA| | | IV | 320 | PCC |<----->| +-------+ +--+ |<--->| candidates | 321 | | | | | | 322 +-----+ | RWA-PCE (coordinator)| | IV-PCE | 323 +----------------------+ +--------------+ 325 (b) 326 Figure 3 PCE architectures for IA-RWA. 328 2.1. RWA PCC to PCE Interface 330 The PCC to PCE interface of Figure 3(a) and the PCC to RWA-PCE 331 (coordinator) interface of Figure 3(b) are the same and we will 332 cover both in this section. The following requirements for these 333 interfaces are arranged by use cases: 335 2.1.1. A new RWA path request 337 The PCReq Message MUST include one or more specific measures of 338 optical signal quality to which all feasible paths should conform: 340 o BER limit 342 o OSNR + Margin 344 o Power 346 o PMD 348 o Residual Dispersion (RD) 350 o Q factor 352 o TBD 353 (Editor's Note: this is not a complete list of optical signal 354 quality measure and subject to further change.) 356 If the PCReq Message does not include the BER limit and no BER limit 357 information related to the specific path request is provisioned at 358 the PCE then the PCE will return an error specifying that a BER 359 limit must be provided. 361 "Margin" means "insurance" (e.g. 3~6dB) for suppliers and operators 362 which are set against unpredictable degradation and other 363 degradation not included in the provided estimates such as that due 364 to fiber nonlinearity. 366 In non-coherent WDM networks, PMD and CD should be carefully 367 considered. However, coherent WDM networks usually have a high 368 tolerance with these two optical signal quality measurements and 369 thus it may not need to be considered. 371 2.1.1.1. Signal Quality Measure TLV 373 This TLV represents all impairment constraints that need to be 374 considered by the PCE to calculate a path that passes the requested 375 measure of signal quality for a signal for a given source and 376 destination. 378 This TLV is repeated one after another until all signal quality 379 types are specified. 381 The TLV type is TBD. 383 The TLV data is defined as follow: 385 0 1 2 3 386 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 1 387 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 388 |P| Signal Quality Type | Reserved | 389 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 390 | Threshold | 391 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 393 The P bit (1 bit): Indicates if the associated impairment is a path 394 level or not. 396 The P bit is set to 1 indicates that the associated impairment is a 397 path level. This means that the impairment is associated with the 398 end-to-end path and the threshold must be satisfied on a path level. 400 The P bit is set to 0 indicates that the associated impairment is a 401 link level. This means the impairment is associated with the link 402 and the threshold must be satisfied on every link of the end-to-end 403 path. 405 The Signal Quality Type (15 bits): indicates the kind of optical 406 signal quality of interest. 408 0: reserved 410 1: BER limit 412 2: OSNR+ Margin 414 3: Power 416 4: PMD 418 5: CD 420 6: Q factor 422 7-up: Reserved for future use 424 Threshold (32 bits) indicates the threshold (upper or lower) to 425 which the specified signal quality measure must satisfy for the 426 path/link (depending on the P bit). 428 The reserved bits MUST be set to 0 on transmit and MUST be ignored 429 on receive. 431 2.1.2. A new RWA path reply 433 The PCRep Message MUST include the route, wavelengths assigned to 434 the route, and an indicator that says if the path conforms to the 435 required quality or not. Moreover, it should also be able to specify 436 a list of impairment compensation information along the chosen 437 route, i.e., the value or value range of optical signal quality 438 parameter that needs to be adjusted, such as power level, in order 439 to achieve the resultant measure of signal quality as given in 440 Section 2.1.2.1. It is suggested to carry this information in the 441 PCEP ERO object. According to [RFC5440], PCEP ERO object is 442 identical to RSVP-TE ERO object. Therefore, it is suggested to 443 modify the RSVP-TE ERO object to accommodate this need. This will be 444 included in a separate draft in the future. 446 In the case where a valid path is not found, the PCRep Message MUST 447 include why the path is not found (e.g., no route, wavelength not 448 found, BER failure, etc.) 450 2.1.2.1. Signal Quality Measure TLV 452 This TLV represents the result of the requested measure of signal 453 quality for a signal for a given source and destination. 455 This TLV is repeated one after another until all signal quality 456 types are specified. 458 The TLV type is TBD. 460 The TLV data is defined as follow: 462 0 1 2 3 463 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 1 464 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 465 |P| Signal Quality Type | Reserved | 466 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 467 | Signal Quality Value | 468 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 470 The P bit (1 bit): Indicates if the associated signal quality 471 measure has passed the threshold or not. 473 The P bit is set to 1 indicates that the associated signal quality 474 measure has passed the threshold. 476 The P bit is set to 0 indicates that the associated signal quality 477 measure has failed the threshold. 479 The Signal Quality Type (15 bits): indicates the kind of optical 480 signal quality of interest. 482 0: reserved 484 1: BER limit 486 2: OSNR_ Margin 488 3: Power 490 4: PMD 492 5: CD 494 6: Q factor 496 7-up: Reserved for future use 498 Signal Quality Value (32 bits) indicates the actual estimated value 499 of the specified signal quality measure for the end-to-end path. 501 TBD: How to encode link based value needs to be determined in the 502 revision. 504 The reserved bits MUST be set to 0 on transmit and MUST be ignored 505 on reception. 507 2.2. RWA-PCE to IV-PCE Interface 509 In [RFC6566] a sequence diagram for the interaction of the PCC, RWA- 510 PCE and IV-PCE of Figure 3(b) was given and is repeated here in 511 Figure 4. The interface between the PCC and the RWA-PCE (acting as 512 the coordinator) was covered in section 2.1. 513 +---+ +-------------+ +-----------------+ 514 |PCC| |RWA-Coord-PCE| |IV-Candidates-PCE| 515 +-+-+ +------+------+ +---------+-------+ 516 ...___ (a) | | 517 | ````---...____ | | 518 | ```-->| | 519 | | | 520 | |--..___ (b) | 521 | | ```---...___ | 522 | | ```---->| 523 | | | 524 | | | 525 | | (c) ___...| 526 | | ___....---'''' | 527 | |<--'''' | 528 | | | 529 | | | 530 | (d) ___...| | 531 | ___....---''' | | 532 |<--''' | | 533 | | | 534 | | | 536 Figure 4 Sequence diagram for the interactions between PCC, RWA- 537 Coordinating-PCE and the IV-Candidates-PCE. 539 The interface between the RWA-Coord-PCE and the IV-Candidates-PCE is 540 specified by the following requirements: 542 1. The PCReq Message from the RWA-Coord-PCE to the IV-Candidate-PCE 543 MUST include an indicator that more than one (candidate) path 544 between source and destination is desired. 546 2. The PCReq message from the RWA-Coord-PCE to the IV-Candidates-PCE 547 MUST include a limit on the number of optical impairment 548 qualified paths to be returned by the IV-PCE. 550 3. The PCReq message from the RWA-Coord-PCE to the IV-Candidates-PCE 551 MAY include wavelength constraints. Note that optical impairments 552 are wavelength sensitive and hence specifying a wavelength 553 constraint may help limit the search for valid paths. This 554 requirement has been already covered in [RFC7449] and is 555 presented here for an illustration purpose. 557 4. The PCRep Message from the IV-Candidates-PCE to RWA-Coord-PCE 558 MUST include a set of optical impairment qualified paths along 559 with any wavelength constraints on those paths. 561 5. The PCRep Message from the IV-Candidates-PCE to RWA-Coord-PCE 562 MUST indicate "no path found" in case where a valid path is not 563 found. 565 6. The PCReq Message from the RWA-Coord-PCE to the IV-Candidate-PCE 566 MAY include one or more specified paths and wavelengths that is 567 to be verified by the IV-PCE. This requirement is necessary when 568 the IV-PCE is allowed to verify specific paths. 570 Note that once the RWA-Coord-PCE receives the resulting paths from 571 the IV Candidates PCE, then the RWA-Coord-PCE computes RWA for the 572 IV qualified candidate paths and sends the result back to the PCC. 574 2.2.1. A new impairment-validated (IV) path request 576 Details on encoding are TBD. 578 2.2.2. A new impairment-validated (IV) path reply 580 Details on encoding are TBD. 582 3. Manageability Considerations 584 Manageability of WSON Routing and Wavelength Assignment (RWA) with 585 PCE must address the following considerations: 587 3.1. Control of Function and Policy 589 In addition to the parameters already listed in Section 8.1 of 590 [RFC5440], a PCEP implementation SHOULD allow configuring the 591 following PCEP session parameters on a PCC: 593 o The ability to send a WSON IA-RWA request. 595 In addition to the parameters already listed in Section 8.1 of 596 [RFC5440], a PCEP implementation SHOULD allow configuring the 597 following PCEP session parameters on a PCE: 599 o The support for WSON IA-RWA. 601 o The maximum number of synchronized path requests associated with 602 WSON IA-RWA per request message. 604 o A set of WSON IA-RWA specific policies (authorized sender, 605 request rate limiter, etc). 607 These parameters may be configured as default parameters for any 608 PCEP session the PCEP speaker participates in, or may apply to a 609 specific session with a given PCEP peer or a specific group of 610 sessions with a specific group of PCEP peers. 612 3.2. Information and Data Models, e.g. MIB module 614 Extensions to the PCEP MIB module defined in [PCEP-MIB] should be 615 defined, so as to cover the WSON IA-RWA information introduced in 616 this document. A future revision of this document will list the 617 information that should be added to the MIB module. 619 3.3. Liveness Detection and Monitoring 621 Mechanisms defined in this document do not imply any new liveness 622 detection and monitoring requirements in addition to those already 623 listed in section 8.3 of [RFC5440]. 625 3.4. Verifying Correct Operation 627 Mechanisms defined in this document do not imply any new 628 verification requirements in addition to those already listed in 629 section 8.4 of [RFC5440] 631 3.5. Requirements on Other Protocols and Functional Components 633 The PCE Discovery mechanisms ([RFC5089] and [RFC5088]) may be used 634 to advertise WSON IA-RWA path computation capabilities to PCCs. 636 3.6. Impact on Network Operation 638 Mechanisms defined in this document do not imply any new network 639 operation requirements in addition to those already listed in 640 section 8.6 of [RFC5440]. 642 4. Security Considerations 644 This document has no requirement for a change to the security models 645 within PCEP [PCEP]. However the additional information distributed 646 in order to address the RWA problem represents a disclosure of 647 network capabilities that an operator may wish to keep private. 648 Consideration should be given to securing this information. 650 5. IANA Considerations 652 A future revision of this document will present requests to IANA for 653 codepoint allocation. 655 6. References 657 6.1. Normative References 659 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 660 Requirement Levels", BCP 14, RFC 2119, March 1997. 662 [RFC3471] Berger, L., "Generalized Multi-Protocol Label Switching 663 (GMPLS) Signaling Functional Description", RFC 3471, 664 January 2003. 666 [RFC3473] Berger, L., Ed., "Generalized Multi-Protocol Label 667 Switching (GMPLS) Signaling Resource ReserVation Protocol- 668 Traffic Engineering (RSVP-TE) Extensions", RFC 3473, 669 January 2003. 671 [RFC5440] Vasseur, JP., Ed. and JL. Le Roux, Ed., "Path Computation 672 Element (PCE) communication Protocol (PCEP)", RFC 5440, 673 March 2009. 675 6.2. Informative References 677 [RFC6163] Lee, Y. and Bernstein, G., W. Imajuku, "Framework for 678 GMPLS and PCE Control of Wavelength Switched Optical 679 Networks", RFC 6163, April 2011. 681 [RFC6566] Lee, Y. and Bernstein, G. (Editors), and D. Li, "Framework 682 for GMPLS and PCE Control of Wavelength Switched Optical 683 Networks", RFC 6566, March, 2012. 685 [RFC7449] Y. Lee, G. Bernstein, J. Martensson, T. Takeda and T. 686 Otani, "PCEP Requirements for WSON Routing and Wavelength 687 Assignment", RFC 7449, February 2015. 689 [RFC5088] Le Roux, JL., Ed., Vasseur, JP., Ed., Ikejiri, Y., and R. 690 Zhang, "OSPF Protocol Extensions for Path Computation 691 Element (PCE) Discovery", RFC 5088, January 2008. 693 [RFC5089] Le Roux, JL., Ed., Vasseur, JP., Ed., Ikejiri, Y., and R. 694 Zhang, "IS-IS Protocol Extensions for Path Computation 695 Element (PCE) Discovery", RFC 5089, January 2008. 697 [RFC4655] Farrel, A., Vasseur, J., and J. Ash, "A Path Computation 698 Element (PCE)-Based Architecture", RFC 4655, August 2006. 700 [RFC4657] Ash, J. and J. Le Roux, "Path Computation Element (PCE) 701 Communication Protocol Generic Requirements", RFC 4657, 702 September 2006. 704 Authors' Addresses 706 Young Lee (Ed.) 707 Huawei Technologies 708 Email: leeyoung@huawei.com 709 Greg Bernstein (Ed.) 710 Grotto Networking 711 Fremont, CA, USA 712 Phone: (510) 573-2237 713 Email: gregb@grotto-networking.com 715 Jonas Martensson 716 Acreo 717 Email:Jonas.Martensson@acreo.se 719 Tomonori Takeda 720 NTT Corporation 721 3-9-11, Midori-Cho 722 Musashino-Shi, Tokyo 180-8585, Japan 723 Email: takeda.tomonori@lab.ntt.co.jp 725 Takehiro Tsuritani 726 2-1-15 Ohara, Fujimino, Saitama, 356-8502, JAPAN 727 KDDI R&D Laboratories Inc. 728 Phone: +81-49-278-7806 729 Email: tsuri@kddilabs.jp 731 Xian Zhang 732 Huawei Technologies 733 F3-5-B R&D Center, Huawei Base 734 Bantian, Longgang District 735 Shenzhen 518129 P.R.China 737 Phone: +86-755-28972913 738 Email: zhang.xian@huawei.com 740 7. Acknowledgments 742 This document was prepared using 2-Word-v2.0.template.dot. 744 Copyright (c) 2018 IETF Trust and the persons identified as authors 745 of the code. 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