idnits 2.17.1 draft-ietf-pce-wson-routing-wavelength-11.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 : ---------------------------------------------------------------------------- ** The document seems to lack an Introduction section. (A line matching the expected section header was found, but with an unexpected indentation: ' 1. Introduction' ) ** The document seems to lack a Security Considerations section. (A line matching the expected section header was found, but with an unexpected indentation: ' 5. Security Considerations' ) ** The document seems to lack an IANA Considerations section. (See Section 2.2 of https://www.ietf.org/id-info/checklist for how to handle the case when there are no actions for IANA.) (A line matching the expected section header was found, but with an unexpected indentation: ' 6. IANA Considerations' ) Miscellaneous warnings: ---------------------------------------------------------------------------- == The copyright year in the IETF Trust and authors Copyright Line does not match the current year == Line 252 has weird spacing: '...1. When the r...' -- The document date (March 11, 2014) is 3692 days in the past. Is this intentional? Checking references for intended status: Informational ---------------------------------------------------------------------------- -- Missing reference section? 'RFC4655' on line 433 looks like a reference -- Missing reference section? 'RFC4657' on line 436 looks like a reference -- Missing reference section? 'RFC6163' on line 455 looks like a reference -- Missing reference section? 'RFC4003' on line 256 looks like a reference -- Missing reference section? 'RFC5440' on line 440 looks like a reference -- Missing reference section? 'PCEP-MIB' on line 444 looks like a reference -- Missing reference section? 'RFC5089' on line 463 looks like a reference -- Missing reference section? 'RFC5088' on line 459 looks like a reference -- Missing reference section? 'RFC2119' on line 421 looks like a reference -- Missing reference section? 'RFC3471' on line 424 looks like a reference -- Missing reference section? 'RFC3473' on line 428 looks like a reference -- Missing reference section? 'RFC6566' on line 450 looks like a reference Summary: 3 errors (**), 0 flaws (~~), 2 warnings (==), 13 comments (--). 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: Informational 4 Expires: September 2014 G. Bernstein 5 Grotto Networking 7 Jonas Martensson 8 Acreo 10 T. Takeda 11 NTT 13 T. Tsuritani 14 KDDI 16 O. G. de Dios 17 Telefonica 19 March 11, 2014 21 PCEP Requirements for WSON Routing and Wavelength Assignment 23 draft-ietf-pce-wson-routing-wavelength-11.txt 25 Status of this Memo 27 This Internet-Draft is submitted to IETF in full conformance with 28 the provisions of BCP 78 and BCP 79. 30 Internet-Drafts are working documents of the Internet Engineering 31 Task Force (IETF), its areas, and its working groups. Note that 32 other groups may also distribute working documents as Internet- 33 Drafts. 35 Internet-Drafts are draft documents valid for a maximum of six 36 months and may be updated, replaced, or obsoleted by other documents 37 at any time. It is inappropriate to use Internet-Drafts as 38 reference material or to cite them other than as "work in progress." 40 The list of current Internet-Drafts can be accessed at 41 http://www.ietf.org/ietf/1id-abstracts.txt 43 The list of Internet-Draft Shadow Directories can be accessed at 44 http://www.ietf.org/shadow.html. 46 This Internet-Draft will expire on September 11, 2014. 48 Copyright Notice 50 Copyright (c) 2014 IETF Trust and the persons identified as the 51 document authors. All rights reserved. 53 This document is subject to BCP 78 and the IETF Trust's Legal 54 Provisions Relating to IETF Documents 55 (http://trustee.ietf.org/license-info) in effect on the date of 56 publication of this document. Please review these documents 57 carefully, as they describe your rights and restrictions with 58 respect to this document. Code Components extracted from this 59 document must include Simplified BSD License text as described in 60 Section 4.e of the Trust Legal Provisions and are provided without 61 warranty as described in the Simplified BSD License. 63 Abstract 65 This memo provides application-specific requirements for the Path 66 Computation Element communication Protocol (PCEP) for the support of 67 Wavelength Switched Optical Networks (WSON). Lightpath provisioning 68 in WSONs requires a routing and wavelength assignment (RWA) process. 69 From a path computation perspective, wavelength assignment is the 70 process of determining which wavelength can be used on each hop of a 71 path and forms an additional routing constraint to optical light 72 path computation. Requirements for Optical impairments will be 73 addressed in a separate document. 75 Conventions used in this document 77 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 78 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this 79 document are to be interpreted as described in RFC-2119 0. 81 Table of Contents 83 1. Introduction ...................................................3 84 2. WSON RWA Processes & Architecture ..............................4 85 3. Requirements ...................................................6 86 3.1. Path Computation Type Option..............................6 87 3.2. RWA Processing............................................6 88 3.3. Bulk RWA Path Request/Reply...............................7 89 3.4. RWA Path Re-optimization Request/Reply....................7 90 3.5. Wavelength Range Constraint...............................7 91 3.6. Wavelength Assignment Preference..........................8 92 3.7. Signal Processing Capability Restriction..................8 93 4. Manageability Considerations ...................................8 94 4.1. Control of Function and Policy............................9 95 4.2. Information and Data Models, e.g. MIB module..............9 96 4.3. Liveness Detection and Monitoring.........................9 97 4.4. Verifying Correct Operation...............................9 98 4.5. Requirements on Other Protocols and Functional Components10 99 4.6. Impact on Network Operation..............................10 100 5. Security Considerations .......................................10 101 6. IANA Considerations ...........................................10 102 7. Acknowledgments ...............................................10 103 8. References ....................................................10 104 8.1. Normative References.....................................10 105 8.2. Informative References...................................11 106 Authors' Addresses...............................................12 107 Intellectual Property Statement..................................12 108 Disclaimer of Validity...........................................13 110 1. Introduction 112 [RFC4655] defines the PCE based Architecture and explains how a Path 113 Computation Element (PCE) may compute Label Switched Paths (LSP) in 114 Multiprotocol Label Switching Traffic Engineering (MPLS-TE) and 115 Generalized MPLS (GMPLS) networks at the request of Path Computation 116 Clients (PCCs). A PCC is shown to be any network component that 117 makes such a request and may be for instance an Optical Switching 118 Element within a Wavelength Division Multiplexing (WDM) network. 119 The PCE, itself, can be located anywhere within the network, and may 120 be within an optical switching element, a Network Management System 121 (NMS) or Operational Support System (OSS), or may be an independent 122 network server. 124 The PCE communications Protocol (PCEP) is the communication protocol 125 used between PCC and PCE, and may also be used between cooperating 126 PCEs. [RFC4657] sets out the common protocol requirements for PCEP. 127 Additional application-specific requirements for PCEP are deferred 128 to separate documents. 130 This document provides a set of application-specific PCEP 131 requirements for support of path computation in Wavelength Switched 132 Optical Networks (WSON). WSON refers to WDM based optical networks 133 in which switching is performed selectively based on the wavelength 134 of an optical signal. 136 The path in WSON is referred to as a lightpath. A lightpath may 137 span multiple fiber links and the path should be assigned a 138 wavelength for each link. A transparent optical network is made up 139 of optical devices that can switch but not convert from one 140 wavelength to another. In a transparent optical network, a lightpath 141 operates on the same wavelength across all fiber links that it 142 traverses. In such case, the lightpath is said to satisfy the 143 wavelength-continuity constraint. Two lightpaths that share a common 144 fiber link cannot be assigned the same wavelength. To do otherwise 145 would result in both signals interfering with each other. Note that 146 advanced additional multiplexing techniques such as polarization 147 based multiplexing are not addressed in this document since the 148 physical layer aspects are not currently standardized. Therefore, 149 assigning the proper wavelength on a lightpath is an essential 150 requirement in the optical path computation process. 152 When a switching node has the ability to perform wavelength 153 conversion the wavelength-continuity constraint can be relaxed, and 154 a lightpath may use different wavelengths on different links along 155 its route from origin to destination. It is, however, to be noted 156 that wavelength converters may be limited due to their relatively 157 high cost, while the number of WDM channels that can be supported in 158 a fiber is also limited. As a WSON can be composed of network nodes 159 that cannot perform wavelength conversion, nodes with limited 160 wavelength conversion, and nodes with full wavelength conversion 161 abilities, wavelength assignment is an additional routing constraint 162 to be considered in all lightpath computation. 164 In this document we first review the processes for routing and 165 wavelength assignment (RWA) used when wavelength continuity 166 constraints are present and then specify requirements for PCEP to 167 support RWA. Requirements for Optical impairments will be addressed 168 in a separate document. 170 The remainder of this document uses terminology from [RFC4655]. 172 2. WSON RWA Processes & Architecture 174 In [RFC6163] three alternative process architectures were given for 175 performing routing and wavelength assignment. These are shown 176 schematically in 0. 178 +-------------------+ 179 | +-------+ +--+ | +-------+ +--+ +-------+ +---+ 180 | |Routing| |WA| | |Routing|--->|WA| |Routing|--->|DWA| 181 | +-------+ +--+ | +-------+ +--+ +-------+ +---+ 182 | Combined | Separate Processes Separate Processes 183 | Processes | WA performed in a 184 +-------------------+ Distributed manner 185 (a) (b) (c) 187 Figure 1. RWA process alternatives. 189 These alternatives have the following properties and impact on PCEP 190 requirements in this document. 192 1. Combined Processes (R&WA) - Here path selection and wavelength 193 assignment are performed as a single process. The requirements 194 for PCC-PCE interaction with such a combined RWA process PCE is 195 addressed in this document. 197 2. Routing separate from Wavelength Assignment (R+WA) - Here the 198 routing process furnishes one or more potential paths to the 199 wavelength assignment process that then performs final path 200 selection and wavelength assignment. The requirements for PCE- 201 PCE interaction with one PCE implementing the routing process and 202 another implementing the wavelength assignment process are not 203 addressed in this document. 205 3. Routing and distributed Wavelength Assignment (R+DWA) - Here a 206 standard path computation (unaware of detailed wavelength 207 availability) takes place, then wavelength assignment is 208 performed along this path in a distributed manner via signaling 209 (RSVP-TE). This alternative should be covered by existing or 210 emerging GMPLS PCEP extensions and does not present new WSON 211 specific requirements. 213 In the previous section various process architectures for 214 implementing RWA have been reviewed. Figure 2 shows one typical PCE 215 based implementation, which is referred to as Combined Process 216 (R&WA). With this architecture, the two processes of routing and 217 wavelength assignment are accessed via a single PCE. This 218 architecture is the base architecture from which the requirements 219 are specified in this document. 221 +----------------------------+ 222 +-----+ | +-------+ +--+ | 223 | | | |Routing| |WA| | 224 | PCC |<----->| +-------+ +--+ | 225 | | | | 226 +-----+ | PCE | 227 +----------------------------+ 229 Figure 2. Combined Process (R&WA) architecture 231 3. Requirements 233 The requirements for the PCC to PCE interface of Figure 2 are 234 specified in this section. 236 3.1. Path Computation Type Option 238 1. A PCEP request MUST include the path computation type. This can 239 be: 241 (i) Both Routing and Wavelength Assignment (RWA), or 243 (ii) Routing only. 245 This requirement is needed to differentiate between the currently 246 supported routing with distributed wavelength assignment option and 247 combined RWA. In case of distributed wavelength assignment option, 248 wavelength assignment will be performed at each node of the route. 250 3.2. RWA Processing 252 1. When the request is a RWA path computation type, the request 253 MUST further include the wavelength assignment options. At the 254 minimum, the following option should be supported: 256 (i) Explicit Label Control (ELC) [RFC4003] 258 (ii) A set of recommended labels. The PCC can select the 259 label based on local policy. 261 Note that option ii) may also be used in R+WA or DWA. 263 2. In case of a RWA computation type, the response MUST include the 264 wavelength(s) assigned to the route and an indication of which 265 label assignment option has been applied (ELC or Label Sets). 267 3. In the case where a valid path is not found, the response MUST 268 include why the path is not found (e.g., no route, wavelength not 269 found, optical quality check failed, etc.) 271 3.3. Bulk RWA Path Request/Reply 273 1. A PCEP request MUST be able to specify an option for bulk RWA 274 path request. Bulk path request is an ability to request a number 275 of simultaneous RWA path requests. 277 2. The PCEP response MUST include the route, wavelength assigned to 278 the route for each RWA path request specified in the original 279 bulk request. 281 3.4. RWA Path Re-optimization Request/Reply 283 1. For a re-optimization request, the request MUST provide both the 284 route and current wavelength to be re-optimized and MAY include 285 the following options: 287 a. Re-optimize the path keeping the same wavelength(s) 289 b. Re-optimize wavelength(s) keeping the same path 291 c. Re-optimize allowing both wavelength and the path to change 293 2. The corresponding response to the re-optimized request MUST 294 provide the re-optimized path and wavelengths. 296 3. In case that the path is not found, the response MUST include why 297 the path is not found (e.g., no route, wavelength not found, both 298 route and wavelength not found, etc.) 300 3.5. Wavelength Range Constraint 302 For any RWA computation type request, the requester (PCC) MAY 303 specify a restriction on the wavelengths to be used. 305 Note that the requestor (PCC) is NOT required to furnish any range 306 restrictions. This restriction is to be interpreted by the PCE as a 307 constraint on the tuning ability of the origination laser 308 transmitter. 310 3.6. Wavelength Assignment Preference 312 1. A RWA computation type request MAY include the requestor 313 preference for (E.g., random assignment, descending order, 314 ascending order, etc.) A response SHOULD follow the requestor 315 preference unless it conflicts with operator's policy. 317 2. A request for 2 or more paths (e.g., 1+1 link disjoint paths) MUST 318 be able to specify an option constraining the path to have the 319 same wavelength(s) assigned. 321 Note that this is extremely useful in the case of protection with 322 single transponder. 324 In a network with wavelength conversion capabilities (e.g. sparse 325 3R regenerators), a request SHOULD be able to indicate whether a 326 single, contiguous wavelength should be allocated or not. In other 327 words, the requesting PCC SHOULD be able to constrain the 328 wavelength continuity even if wavelength conversion is available. 330 3.7. Signal Processing Capability Restriction 332 A request MUST be able to specify restrictions for signal 333 compatibility either on the endpoints or any given links. The 334 following signal processing capabilities should be supported at a 335 minimum: 337 o Modulation Type List 339 o FEC Type List 341 4. Manageability Considerations 343 Manageability of WSON Routing and Wavelength Assignment (RWA) with 344 PCE must address the following considerations: 346 4.1. Control of Function and Policy 348 In addition to the parameters already listed in Section 8.1 of 349 [RFC5440], a PCEP implementation SHOULD allow configuring the 350 following PCEP session parameters on a PCC: 352 o The ability to send a WSON RWA request. 354 In addition to the parameters already listed in Section 8.1 of 355 [RFC5440], a PCEP implementation SHOULD allow configuring the 356 following PCEP session parameters on a PCE: 358 o The support for WSON RWA. 360 o The maximum number of bulk path requests associated with WSON 361 RWA per request message. 363 These parameters may be configured as default parameters for any 364 PCEP session the PCEP speaker participates in, or may apply to a 365 specific session with a given PCEP peer or a specific group of 366 sessions with a specific group of PCEP peers. 368 4.2. Information and Data Models, e.g. MIB module 370 As this document only concerns the requirements to support WSON RWA, 371 no additional MIB module is defined in this document. However, the 372 corresponding solution draft will list the information that should 373 be added to the PCE MIB module defined in [PCEP-MIB]. 375 4.3. Liveness Detection and Monitoring 377 Mechanisms defined in this document do not imply any new liveness 378 detection and monitoring requirements in addition to those already 379 listed in section 8.3 of [RFC5440]. 381 4.4. Verifying Correct Operation 383 Mechanisms defined in this document do not imply any new 384 verification requirements in addition to those already listed in 385 section 8.4 of [RFC5440] 386 4.5. Requirements on Other Protocols and Functional Components 388 The PCE Discovery mechanisms ([RFC5089] and [RFC5088]) may be used 389 to advertise WSON RWA path computation capabilities to PCCs. 391 4.6. Impact on Network Operation 393 Mechanisms defined in this document do not imply any new network 394 operation requirements in addition to those already listed in 395 section 8.6 of [RFC5440]. 397 5. Security Considerations 399 This document has no requirement for a change to the security models 400 within PCEP [RFC5440]. However the additional information 401 distributed in order to address the RWA problem represents a 402 disclosure of network capabilities that an operator may wish to keep 403 private. Consideration should be given to securing this information. 405 6. IANA Considerations 407 This informational document does not make any requests for IANA 408 action. 410 7. Acknowledgments 412 The authors would like to thank Adrian Farrel for many helpful 413 comments that greatly improved the contents of this draft. 415 This document was prepared using 2-Word-v2.0.template.dot. 417 8. References 419 8.1. Normative References 421 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 422 Requirement Levels", BCP 14, RFC 2119, March 1997. 424 [RFC3471] Berger, L., "Generalized Multi-Protocol Label Switching 425 (GMPLS) Signaling Functional Description", RFC 3471, 426 January 2003. 428 [RFC3473] Berger, L., Ed., "Generalized Multi-Protocol Label 429 Switching (GMPLS) Signaling Resource ReserVation Protocol- 430 Traffic Engineering (RSVP-TE) Extensions", RFC 3473, 431 January 2003. 433 [RFC4655] Farrel, A., Vasseur, J., and J. Ash, "A Path Computation 434 Element (PCE)-Based Architecture", RFC 4655, August 2006. 436 [RFC4657] Ash, J. and J. Le Roux, "Path Computation Element (PCE) 437 Communication Protocol Generic Requirements", RFC 4657, 438 September 2006. 440 [RFC5440] Vasseur, JP., Ed. and JL. Le Roux, Ed., "Path Computation 441 Element (PCE) communication Protocol", RFC 5440, March 442 2009. 444 [PCEP-MIB] Koushik, K, et al., "PCE communication protocol(PCEP) 445 Management Information Base", draft-ietf-pce-pcep-mib, 446 work in progress. 448 8.2. Informative References 450 [RFC6566] Lee, Y. and Bernstein, G. (Editors), D. Li and G. 451 Martinelli "A Framework for the Control and Measurement of 452 Wavelength Switched Optical Networks (WSON) with 453 Impairments", RFC 6566, March 2012. 455 [RFC6163] Y. Lee, G. Bernstein, W. Imajuku, "Framework for GMPLS 456 and PCE Control of Wavelength Switched Optical Networks", 457 RFC 6163, April 2011. 459 [RFC5088] Le Roux, JL., Ed., Vasseur, JP., Ed., Ikejiri, Y., and R. 460 Zhang, "OSPF Protocol Extensions for Path Computation 461 Element (PCE) Discovery", RFC 5088, January 2008. 463 [RFC5089] Le Roux, JL., Ed., Vasseur, JP., Ed., Ikejiri, Y., and R. 464 Zhang, "IS-IS Protocol Extensions for Path Computation 465 Element (PCE) Discovery", RFC 5089, January 2008. 467 Authors' Addresses 469 Young Lee (Ed.) 470 Huawei Technologies 471 5340 Legacy Drive, Building 3 472 Plano, TX 75245, USA 473 Phone: (469)277-5838 474 Email: leeyoung@huawei.com 476 Greg Bernstein (Ed.) 477 Grotto Networking 478 Fremont, CA, USA 479 Phone: (510) 573-2237 480 Email: gregb@grotto-networking.com 482 Jonas Martensson 483 Acreo 484 Email:Jonas.Martensson@acreo.se 486 Tomonori Takeda 487 NTT Corporation 488 3-9-11, Midori-Cho 489 Musashino-Shi, Tokyo 180-8585, Japan 490 Email: takeda.tomonori@lab.ntt.co.jp 492 Takehiro Tsuritani 493 KDDI R&D Laboratories, Inc. 494 2-1-15 Ohara Kamifukuoka Saitama, 356-8502. Japan 495 Phone: +81-49-278-7357 496 Email: tsuri@kddilabs.jp 498 Oscar Gonzalez de Dios 499 Telefonica Investigacion y Desarrollo 500 C/ Emilio Vargas 6 501 Madrid, 28043 502 Spain 503 Phone: +34 91 3374013 504 Email: ogondio@tid.es 506 Intellectual Property Statement 508 The IETF Trust takes no position regarding the validity or scope of 509 any Intellectual Property Rights or other rights that might be 510 claimed to pertain to the implementation or use of the technology 511 described in any IETF Document or the extent to which any license 512 under such rights might or might not be available; nor does it 513 represent that it has made any independent effort to identify any 514 such rights. 516 Copies of Intellectual Property disclosures made to the IETF 517 Secretariat and any assurances of licenses to be made available, or 518 the result of an attempt made to obtain a general license or 519 permission for the use of such proprietary rights by implementers or 520 users of this specification can be obtained from the IETF on-line 521 IPR repository at http://www.ietf.org/ipr 523 The IETF invites any interested party to bring to its attention any 524 copyrights, patents or patent applications, or other proprietary 525 rights that may cover technology that may be required to implement 526 any standard or specification contained in an IETF Document. 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