idnits 2.17.1 draft-ietf-pce-wson-rwa-ext-03.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 18 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 1, 2015) is 3250 days in the past. Is this intentional? Checking references for intended status: Full Standard ---------------------------------------------------------------------------- (See RFCs 3967 and 4897 for information about using normative references to lower-maturity documents in RFCs) == Missing Reference: 'X X' is mentioned on line 193, but not defined == Missing Reference: 'GEN-ENCODE' is mentioned on line 198, but not defined == Missing Reference: 'Gen-Encode' is mentioned on line 309, but not defined == Missing Reference: 'RFC2863' is mentioned on line 400, but not defined == Missing Reference: 'RWA-Encode' is mentioned on line 554, but not defined == Missing Reference: 'RFC5420' is mentioned on line 644, but not defined == Missing Reference: 'LSPA-ERO' is mentioned on line 661, but not defined == Missing Reference: 'PCEP' is mentioned on line 761, but not defined == Missing Reference: 'PCEP-MIB' is mentioned on line 730, but not defined == Missing Reference: 'RFC5089' is mentioned on line 749, but not defined == Missing Reference: 'RFC5088' is mentioned on line 749, but not defined == Unused Reference: 'RFC3471' is defined on line 888, but no explicit reference was found in the text == Unused Reference: 'RFC3473' is defined on line 892, but no explicit reference was found in the text == Unused Reference: 'RFC3477' is defined on line 897, but no explicit reference was found in the text == Unused Reference: 'PCEP-Layer' is defined on line 923, but no explicit reference was found in the text == Unused Reference: 'RFC6163' is defined on line 928, but no explicit reference was found in the text == Unused Reference: 'OSPF-Imp' is defined on line 971, but no explicit reference was found in the text ** Downref: Normative reference to an Proposed Standard draft: draft-ietf-pce-gmpls-pcep-extensions (ref. 'PCEP-GMPLS') ** Downref: Normative reference to an Proposed Standard draft: draft-margaria-ccamp-lsp-attribute-ero (ref. 'RSVP-RO') ** Downref: Normative reference to an Proposed Standard draft: draft-ietf-pce-inter-layer-ext (ref. 'PCEP-Layer') ** Downref: Normative reference to an Informational RFC: RFC 6163 ** Downref: Normative reference to an Informational RFC: RFC 7449 ** Downref: Normative reference to an Proposed Standard RFC: RFC 6205 ** Downref: Normative reference to an Proposed Standard draft: draft-ietf-ccamp-wson-signaling (ref. 'WSON-Sign') ** Downref: Normative reference to an Proposed Standard draft: draft-ietf-ccamp-wson-signal-compatibility-ospf (ref. 'WSON-OSPF') ** Downref: Normative reference to an Informational RFC: RFC 7446 ** Downref: Normative reference to an Proposed Standard draft: draft-ietf-ccamp-general-constraint-encode (ref. 'GEN-Encode') ** Downref: Normative reference to an Informational draft: draft-ietf-ccamp-wson-impairments (ref. 'WSON-Imp') -- Possible downref: Normative reference to a draft: ref. 'RSVP-Imp' ** Downref: Normative reference to an Experimental draft: draft-eb-ccamp-ospf-wson-impairments (ref. 'OSPF-Imp') Summary: 13 errors (**), 0 flaws (~~), 18 warnings (==), 2 comments (--). Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 1 Network Working Group Y. Lee, Ed. 2 Internet Draft Huawei Technologies 4 Intended status: Standard R. Casellas, Ed. 5 Expires: November 2015 CTTC 7 June 1, 2015 9 PCEP Extension for WSON Routing and Wavelength Assignment 11 draft-ietf-pce-wson-rwa-ext-03.txt 13 Abstract 15 This document provides the Path Computation Element communication 16 Protocol (PCEP) extensions for the support of Routing and Wavelength 17 Assignment (RWA) in Wavelength Switched Optical Networks (WSON). 18 Lightpath provisioning in WSONs requires a routing and wavelength 19 assignment (RWA) process. From a path computation perspective, 20 wavelength assignment is the process of determining which wavelength 21 can be used on each hop of a path and forms an additional routing 22 constraint to optical light path computation. 24 Status of this Memo 26 This Internet-Draft is submitted to IETF in full conformance with 27 the provisions of BCP 78 and BCP 79. 29 Internet-Drafts are working documents of the Internet Engineering 30 Task Force (IETF), its areas, and its working groups. Note that 31 other groups may also distribute working documents as Internet- 32 Drafts. 34 Internet-Drafts are draft documents valid for a maximum of six 35 months and may be updated, replaced, or obsoleted by other documents 36 at any time. It is inappropriate to use Internet-Drafts as 37 reference material or to cite them other than as "work in progress." 39 The list of current Internet-Drafts can be accessed at 40 http://www.ietf.org/ietf/1id-abstracts.txt 41 The list of Internet-Draft Shadow Directories can be accessed at 42 http://www.ietf.org/shadow.html. 44 This Internet-Draft will expire on November 1, 2015. 46 Copyright Notice 48 Copyright (c) 2015 IETF Trust and the persons identified as the 49 document authors. All rights reserved. 51 This document is subject to BCP 78 and the IETF Trust's Legal 52 Provisions Relating to IETF Documents 53 (http://trustee.ietf.org/license-info) in effect on the date of 54 publication of this document. Please review these documents 55 carefully, as they describe your rights and restrictions with 56 respect to this document. Code Components extracted from this 57 document must include Simplified BSD License text as described in 58 Section 4.e of the Trust Legal Provisions and are provided without 59 warranty as described in the Simplified BSD License. 61 Table of Contents 63 1. Terminology....................................................3 64 2. Requirements Language..........................................3 65 3. Introduction...................................................3 66 4. Encoding of a RWA Path Request.................................6 67 4.1. Wavelength Assignment (WA) Object.........................6 68 4.2. Wavelength Restriction Constraint TLV.....................8 69 4.2.1. Link Identifier Field...............................10 70 4.2.2. Wavelength Restriction Field........................12 71 4.3. Signal processing capability restrictions................13 72 4.3.1. Signal Processing Exclusion XRO Sub-Object..........14 73 4.3.2. IRO sub-object: signal processing inclusion.........14 74 5. Encoding of a RWA Path Reply..................................15 75 5.1. Error Indicator..........................................16 76 5.2. NO-PATH Indicator........................................17 77 6. Manageability Considerations..................................17 78 6.1. Control of Function and Policy...........................18 79 6.2. Information and Data Models, e.g. MIB module.............18 80 6.3. Liveness Detection and Monitoring........................18 81 6.4. Verifying Correct Operation..............................18 82 6.5. Requirements on Other Protocols and Functional Components19 83 6.6. Impact on Network Operation..............................19 84 7. Security Considerations.......................................19 85 8. IANA Considerations...........................................19 86 9. Acknowledgments...............................................22 87 10. References...................................................22 88 10.1. Informative References..................................22 89 11. Contributors.................................................24 90 Authors' Addresses...............................................25 91 Intellectual Property Statement..................................25 92 Disclaimer of Validity...........................................26 94 1. Terminology 96 This document uses the terminology defined in [RFC4655], and 97 [RFC5440]. 99 2. Requirements Language 101 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 102 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this 103 document are to be interpreted as described in [RFC2119]. 105 3. Introduction 107 [RFC4655] defines a PCE based path computation architecture and 108 explains how a Path Computation Element (PCE) may compute Label 109 Switched Paths (LSP) in Multiprotocol Label Switching Traffic 110 Engineering (MPLS-TE) and Generalized MPLS (GMPLS) networks at the 111 request of Path Computation Clients (PCCs). A PCC is said to be any 112 network component that makes such a request and may be, for 113 instance, an Optical Switching Element within a Wavelength Division 114 Multiplexing (WDM) network. The PCE, itself, can be located 115 anywhere within the network, and may be within an optical switching 116 element, a Network Management System (NMS) or Operational Support 117 System (OSS), or may be an independent network server. 119 The PCE communications Protocol (PCEP) is the communication protocol 120 used between a PCC and a PCE, and may also be used between 121 cooperating PCEs. [RFC4657] sets out the common protocol 122 requirements for PCEP. Additional application-specific requirements 123 for PCEP are deferred to separate documents. 125 This document provides the PCEP extensions for the support of 126 Routing and Wavelength Assignment (RWA) in Wavelength Switched 127 Optical Networks (WSON) based on the requirements specified in 128 [RFC7449]. 130 WSON refers to WDM based optical networks in which switching is 131 performed selectively based on the wavelength of an optical signal. 132 In this document, it is assumed that wavelength converters require 133 electrical signal regeneration. Consequently, WSONs can be 134 transparent (A transparent optical network is made up of optical 135 devices that can switch but not convert from one wavelength to 136 another, all within the optical domain) or translucent (3R 137 regenerators are sparsely placed in the network). 139 A LSC Label Switched Path (LSP) may span one or several transparent 140 segments, which are delimited by 3R regenerators (typically with 141 electronic regenerator and optional wavelength conversion). Each 142 transparent segment or path in WSON is referred to as an optical 143 path. An optical path may span multiple fiber links and the path 144 should be assigned the same wavelength for each link. In such case, 145 the optical path is said to satisfy the wavelength-continuity 146 constraint. Figure 1 illustrates the relationship between a LSC LSP 147 and transparent segments (optical paths). 149 +---+ +-----+ +-----+ +-----+ +-----+ 150 | |I1 | | | | | | I2| | 151 | |o------| |-------[(3R) ]------| |--------o| | 152 | | | | | | | | | | 153 +---+ +-----+ +-----+ +-----+ +-----+ 154 [X LSC] [LSC LSC] [LSC LSC] [LSC X] SwCap 155 <-------> <-------> <-----> <-------> 156 <-----------------------><----------------------> 157 Transparent Segment Transparent Segment 158 <-------------------------------------------------> 159 LSC LSP 161 Figure 1 Illustration of a LSC LSP and transparent segments 163 Note that two optical paths within a WSON LSP need not operate on 164 the same wavelength (due to the wavelength conversion capabilities). 165 Two optical paths that share a common fiber link cannot be assigned 166 the same wavelength. To do otherwise would result in both signals 167 interfering with each other. Note that advanced additional 168 multiplexing techniques such as polarization based multiplexing are 169 not addressed in this document since the physical layer aspects are 170 not currently standardized. Therefore, assigning the proper 171 wavelength on a lightpath is an essential requirement in the optical 172 path computation process. 174 When a switching node has the ability to perform wavelength 175 conversion, the wavelength-continuity constraint can be relaxed, and 176 a LSC Label Switched Path (LSP) may use different wavelengths on 177 different links along its route from origin to destination. It is, 178 however, to be noted that wavelength converters may be limited due 179 to their relatively high cost, while the number of WDM channels that 180 can be supported in a fiber is also limited. As a WSON can be 181 composed of network nodes that cannot perform wavelength conversion, 182 nodes with limited wavelength conversion, and nodes with full 183 wavelength conversion abilities, wavelength assignment is an 184 additional routing constraint to be considered in all lightpath 185 computation. 187 For example (see Figure 1), within a translucent WSON, a LSC LSP may 188 be established between interfaces I1 and I2, spanning 2 transparent 189 segments (optical paths) where the wavelength continuity constraint 190 applies (i.e. the same unique wavelength MUST be assigned to the LSP 191 at each TE link of the segment). If the LSC LSP induced a Forwarding 192 Adjacency / TE link, the switching capabilities of the TE link would 193 be [X X] where X < LSC (PSC, TDM, ...). 195 This document aligns with GMPLS extensions for PCEP [PCEP-GMPLS] for 196 generic property such as label, label-set and label assignment 197 noting that wavelength is a type of label. Wavelength restrictions 198 and constraints are also formulated in terms of labels per [GEN- 199 ENCODE]. 201 The optical modulation properties, which are also referred to as 202 signal compatibility, are already considered in signaling in [RWA- 203 Encode] and [WSON-OSPF]. In order to improve the signal quality and 204 limit some optical effects several advanced modulation processing 205 are used. Those modulation properties contribute not only to optical 206 signal quality checks but also constrain the selection of sender and 207 receiver, as they should have matching signal processing 208 capabilities. This document includes signal compatibility 209 constraints as part of RWA path computation. That is, the signal 210 processing capabilities (e.g., modulation and FEC) by the means of 211 optical interface class (OIC) must be compatible between the sender 212 and the receiver of the optical path across all optical elements. 214 This document, however, does not address optical impairments as part 215 of RWA path computation. See [WSON-Imp] and [RSVP-Imp] for more 216 information on optical impairments and GMPLS. 218 4. Encoding of a RWA Path Request 220 Figure 2 shows one typical PCE based implementation, which is 221 referred to as the Combined Process (R&WA). With this architecture, 222 the two processes of routing and wavelength assignment are accessed 223 via a single PCE. This architecture is the base architecture from 224 which the requirements have been specified in [RFC7449] and the PCEP 225 extensions that are going to be specified in this document based on 226 this architecture. 228 +----------------------------+ 229 +-----+ | +-------+ +--+ | 230 | | | |Routing| |WA| | 231 | PCC |<----->| +-------+ +--+ | 232 | | | | 233 +-----+ | PCE | 234 +----------------------------+ 236 Figure 2 Combined Process (R&WA) architecture 238 4.1. Wavelength Assignment (WA) Object 240 Wavelength allocation can be performed by the PCE by different 241 means: 243 (a) By means of Explicit Label Control (ELC) where the PCE allocates 244 which label to use for each interface/node along the path. in the 245 sense that the allocated labels MAY appear after an interface route 246 subobject. 247 (b) By means of a Label Set where the PCE provides a range of 248 potential labels to allocate by each node along the path. 250 Option (b) allows distributed label allocation (performed during 251 signaling) to complete wavelength assignment. 253 Additionally, given a range of potential labels to allocate, the 254 request SHOULD convey the heuristic / mechanism to the allocation. 256 The format of a PCReq message after incorporating the WA object is 257 as follows: 259 ::= 261 [] 262 264 Where: 266 ::=[] 268 ::= 270 272 274 [other optional objects...] 276 If the WA object is present in the request, it MUST be encoded after 277 the ENDPOINTS object. 279 The format of the Wavelength Assignment (WA) object body is as 280 follows: 282 0 1 2 3 283 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 1 284 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 285 | Flags | O |M| 286 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 287 | Wavelength Restriction Constraint TLV | 288 . . 289 . . 290 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 291 // Optional TLVs // 292 | | 293 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 295 Figure 3 WA Object 297 o Flags (32 bits) 299 The following new flags SHOULD be set 300 . M (Mode - 1 bit): M bit is used to indicate the mode of 301 wavelength assignment. When M bit is set to 1, this indicates 302 that the label assigned by the PCE must be explicit. That is, 303 the selected way to convey the allocated wavelength is by means 304 of Explicit Label Control (ELC) [RFC4003] for each hop of a 305 computed LSP. Otherwise, the label assigned by the PCE needs 306 not be explicit (i.e., it can be suggested in the form of label 307 set objects in the corresponding response, to allow distributed 308 WA. In such case, the PCE MUST return a Label Set Field as 309 described in Section 2.6 of [Gen-Encode] in the response. See 310 Section 5 of this document for the encoding discussion of a 311 Label Set Field in a PCRep message. 313 . O (Order - - 3 bits): O bit is used to indicate the wavelength 314 assignment constraint in regard to the order of wavelength 315 assignment to be returned by the PCE. This case is only applied 316 when M bit is set to ''explicit.'' The following indicators 317 should be defined: 319 000 - - Reserved 321 001 - - Random Assignment 323 010 - - First Fit (FF) in descending Order 325 011 - - First Fit (FF) in ascending Order 327 100 - - Last Fit (LF) in ascending Order 329 101 - - Last Fit (LF) in descending Order 331 110 - - Unspecified 333 111 - Reserved 335 4.2. Wavelength Restriction Constraint TLV 337 For any request that contains a wavelength assignment, the requester 338 (PCC) MUST be able to specify a restriction on the wavelengths to be 339 used. This restriction is to be interpreted by the PCE as a 340 constraint on the tuning ability of the origination laser 341 transmitter or on any other maintenance related constraints. Note 342 that if the LSP LSC spans different segments, the PCE MUST have 343 mechanisms to know the tunability restrictions of the involved 344 wavelength converters / regenerators, e.g. by means of the TED 345 either via IGP or NMS. Even if the PCE knows the tunability of the 346 transmitter, the PCC MUST be able to apply additional constraints to 347 the request. 349 The format of the Wavelength Restriction Constraint TLV is as 350 follows: 352 ::= 354 356 ( )... 358 Where 360 ::= [] 362 See Section 4.2.1. for the encoding of the Link Identifiers Field. 364 The Wavelength Restriction Constraint TLV type is TBD, recommended 365 value is TBD. This TLV MAY appear more than once to be able to 366 specify multiple restrictions. 368 The TLV data is defined as follows: 370 0 1 2 3 371 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 1 372 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 373 | Action | Count | Reserved | 374 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 375 | Link Identifiers | 376 | . . . | 377 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 378 | Wavelength Restriction Field | 379 // . . . . // 380 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 382 Figure 4 Wavelength Restriction Constraint TLV Encoding 384 o Action: 8 bits 385 . 0 - Inclusive List indicates that one or more link identifiers 386 are included in the Link Set. Each identifies a separate link 387 that is part of the set. 389 . 1 - Inclusive Range indicates that the Link Set defines a 390 range of links. It contains two link identifiers. The first 391 identifier indicates the start of the range (inclusive). The 392 second identifier indicates the end of the range (inclusive). 393 All links with numeric values between the bounds are 394 considered to be part of the set. A value of zero in either 395 position indicates that there is no bound on the corresponding 396 portion of the range. Note that the Action field can be set to 397 0 when unnumbered link identifier is used. 399 Note that "interfaces" such as those discussed in the Interfaces MIB 400 [RFC2863] are assumed to be bidirectional. 402 o Count: The number of the link identifiers (8 bits) 404 Note that a PCC MAY add a Wavelength restriction that applies to all 405 links by setting the Count field to zero and specifying just a set 406 of wavelengths. 408 Note that all link identifiers in the same list must be of the same 409 type. 411 o Reserved: Reserved for future use (16 bits) 413 o Link Identifiers: Identifies each link ID for which restriction 414 is applied. The length is dependent on the link format and the Count 415 field. See Section 4.2.1. for Link Identifier encoding and Section 416 4.2.2. for the Wavelength Restriction Field encoding, respectively. 418 4.2.1. Link Identifier Field 420 The link identifier field can be an IPv4, IPv6 or unnumbered 421 interface ID. 423 ::= 424 | | 426 The encoding of each case is as follows: 428 IPv4 prefix Entry 430 0 1 2 3 431 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 1 432 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 433 | Type = 1 | IPv4 address (4 bytes) | 434 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 435 | IPv4 address (continued) | Prefix Length | 436 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 438 IPv6 prefix Sub-TLV 440 0 1 2 3 441 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 1 442 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 443 | Type = 2 | IPv6 address (16 bytes) | 444 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 445 | IPv6 address (continued) | 446 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 447 | IPv6 address (continued) | 448 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 449 | IPv6 address (continued) | 450 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 451 | IPv6 address (continued) | Prefix Length | 452 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 454 Unnumbered Interface ID Sub-TLV 456 0 1 2 3 457 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 1 458 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 459 | Type = 3 | Reserved | 460 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 461 | TE Node ID | 462 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 463 | Interface ID | 464 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 466 4.2.2. Wavelength Restriction Field 468 The Wavelength Restriction Field of the wavelength restriction TLV 469 is encoded as a Label Set field as specified in [GEN-Encode] section 470 2.6, as shown below, with base label encoded as a 32 bit LSC label, 471 defined in [RFC6205]. See [RFC6205] for a description of Grid, C.S, 472 Identifier and n, as well as [GEN-Encode] for the details of each 473 action. 475 0 1 2 3 477 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 1 479 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 480 | Action| Num Labels | Length | 481 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 482 |Grid | C.S | Identifier | n | 483 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 484 | Additional fields as necessary per action | 485 | | 486 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 488 Action: 490 0 - Inclusive List 492 1 - Exclusive List 494 2 - Inclusive Range 496 3 - Exclusive Range 498 4 - Bitmap Set 500 Num Labels is generally the number of labels. It has a specific 501 meaning depending on the action value. Num Labels is a 12 bit 502 integer. 504 Length is the length in bytes of the entire label set field. 506 See Sections 2.6.1 - 2.6.3 of [GEN-Encode] for details on 507 additional field discussion for each action. 509 4.3. Signal processing capability restrictions 511 Path computation for WSON include the check of signal processing 512 capabilities, those capability MAY be provided by the IGP, however 513 this is not a MUST. Moreover, a PCC should be able to indicate 514 additional restrictions for those signal compatibility, either on 515 the endpoint or any given link. 517 The supported signal processing capabilities are the one described 518 in [RFC7446]: 520 . Optical Interface Class List 522 . Bit Rate 524 . Client Signal 526 The Bit Rate restriction is already expressed in [PCEP-GMPLS] in the 527 BANDWIDTH object. 529 In order to support the Optical Interface Class information and the 530 Client Signal information new TLVs are introduced as endpoint- 531 restriction in the END-POINTS type Generalized endpoint: 533 . Client Signal TLV 535 . Optical Interface Class List TLV 537 The END-POINTS type generalized endpoint is extended as follows: 539 ::= 541 543 [...] 545 Where 547 signal-compatibility-restriction ::= 548 550 The encoding for the Optical Interface Class List is described in 551 Section 4.1 of [RWA-Encode]. 553 The encoding for the Client Signal Information is described in 554 Section 4.2 of [RWA-Encode]. 556 4.3.1. Signal Processing Exclusion XRO Sub-Object 558 The PCC/PCE should be able to exclude particular types of signal 559 processing along the path in order to handle client restriction or 560 multi-domain path computation. 562 In order to support the exclusion a new XRO sub-object is defined: 563 the signal processing exclusion: 565 0 1 2 3 567 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 1 568 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 569 |X| Type = X | Length | Reserved | Attribute | 570 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 571 | sub-sub objects | 572 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 574 Figure 5 Signaling Processing XRO Sub-Object 576 The Attribute field indicates how the exclusion sub-object is to be 577 interpreted. The Attribute can only be 0 (Interface) or 1 (Node). 579 The sub-sub objects are encoded as in RSVP signaling definition 580 [WSON-Sign]. 582 4.3.2. IRO sub-object: signal processing inclusion 584 Similar to the XRO sub-object the PCC/PCE should be able to include 585 particular types of signal processing along the path in order to 586 handle client restriction or multi-domain path computation. 588 This is supported by adding the sub-object ''processing'' defined for 589 ERO in [WSON-Sign] to the PCEP IRO object. 591 5. Encoding of a RWA Path Reply 593 This section provides the encoding of a RWA Path Reply for 594 wavelength allocation as discussed in Section 4. Recall that 595 wavelength allocation can be performed by the PCE by different 596 means: 598 (a) By means of Explicit Label Control (ELC) where the PCE allocates 599 which label to use for each interface/node along the path. in the 600 sense that the allocated labels MAY appear after an interface route 601 subobject. 602 (b) By means of a Label Set where the PCE provides a range of 603 potential labels to allocate by each node along the path. 605 Option (b) allows distributed label allocation (performed during 606 signaling) to complete wavelength allocation. 608 The Wavelength Allocation TLV type is TBD, recommended value is TBD. 609 The TLV data is defined as follows: 611 0 1 2 3 612 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 1 613 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 614 | Reserved |M| 615 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 616 | Link Identifier | 617 | | 618 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 619 | Allocated Wavelength(s) | 620 // . . . . // 621 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 623 Figure 6 Wavelength Allocation TLV Encoding 625 o Reserved: Reserved for future use (31 bits) 627 o M (Mode): 1 bit 629 . 0 - - indicates the allocation is under Explicit Label Control. 631 . 1 - - indicates the allocation is expressed in Label Sets. 633 Note that all link identifiers in the same list must be of the same 634 type. 636 o Link Identifier (variable): Identifies the interface to which 637 assignment wavelength(s) is applied. See Section 4.2.1. for Link 638 Identifier encoding. 640 o Assigned Wavelength(s) (variable): Indicates the assigned 641 wavelength(s) to the link identifier. See Section 4.2.2 for encoding 642 details. 644 This TLV is encoded as an attributes TLV, per [RFC5420], which is 645 carried in the ERO LSP Attribute Subobjects per [RSVP-RO]. The type 646 value of the Wavelength Restriction Constraint TLV is TBD by IANA. 648 The ERO is used to encode the path of a TE LSP through the network. 649 The ERO is carried within a given path of a PCEP response, which is 650 in turn carried in a PCRep message to provide the computed TE LSP if 651 the path computation was successful. The preferred way to convey the 652 allocated wavelength is by means of Explicit Label Control (ELC) 653 [RFC4003]. 654 In order to encode wavelength assignment, the Wavelength Assignment 655 (WA) Object needs to be employed to be able to specify wavelength 656 assignment. Since each segment of the computed optical path is 657 associated with wavelength assignment, the WA Object should be 658 aligned with the ERO object. 660 Encoding details will be provided further revisions and will be 661 aligned as much as possible with [WSON-Sign] and [LSPA-ERO] 663 5.1. Error Indicator 665 To indicate errors associated with the RWA request, a new Error Type 666 (TDB) and subsequent error-values are defined as follows for 667 inclusion in the PCEP-ERROR Object: 669 A new Error-Type (TDB) and subsequent error-values are defined as 670 follows: 672 . Error-Type=TBD; Error-value=1: if a PCE receives a RWA request 673 and the PCE is not capable of processing the request due to 674 insufficient memory, the PCE MUST send a PCErr message with a 675 PCEP-ERROR Object (Error-Type=TDB) and an Error-value(Error- 676 value=1). The PCE stops processing the request. The 677 corresponding RWA request MUST be cancelled at the PCC. 679 . Error-Type=TBD; Error-value=2: if a PCE receives a RWA request 680 and the PCE is not capable of RWA computation, the PCE MUST 681 send a PCErr message with a PCEP-ERROR Object (Error-Type=TDB) 682 and an Error-value (Error-value=2). The PCE stops processing 683 the request. The corresponding RWA computation MUST be 684 cancelled at the PCC. 686 5.2. NO-PATH Indicator 688 To communicate the reason(s) for not being able to find RWA for the 689 path request, the NO-PATH object can be used in the corresponding 690 response. The format of the NO-PATH object body is defined in 691 [RFC5440]. The object may contain a NO-PATH-VECTOR TLV to provide 692 additional information about why a path computation has failed. 694 One new bit flag are defined to be carried in the Flags field in the 695 NO-PATH-VECTOR TLV carried in the NO-PATH Object. 697 . Bit TDB: When set, the PCE indicates no feasible route was 698 found that meets all the constraints (e.g., wavelength 699 restriction, signal compatibility, etc.) associated with RWA. 701 6. Manageability Considerations 703 Manageability of WSON Routing and Wavelength Assignment (RWA) with 704 PCE must address the following considerations: 706 6.1. Control of Function and Policy 708 In addition to the parameters already listed in Section 8.1 of 709 [PCEP], a PCEP implementation SHOULD allow configuring the following 710 PCEP session parameters on a PCC: 712 . The ability to send a WSON RWA request. 714 In addition to the parameters already listed in Section 8.1 of 715 [PCEP], a PCEP implementation SHOULD allow configuring the following 716 PCEP session parameters on a PCE: 718 . The support for WSON RWA. 720 . A set of WSON RWA specific policies (authorized sender, 721 request rate limiter, etc). 723 These parameters may be configured as default parameters for any 724 PCEP session the PCEP speaker participates in, or may apply to a 725 specific session with a given PCEP peer or a specific group of 726 sessions with a specific group of PCEP peers. 728 6.2. Information and Data Models, e.g. MIB module 730 Extensions to the PCEP MIB module defined in [PCEP-MIB] should be 731 defined, so as to cover the WSON RWA information introduced in this 732 document. A future revision of this document will list the 733 information that should be added to the MIB module. 735 6.3. Liveness Detection and Monitoring 737 Mechanisms defined in this document do not imply any new liveness 738 detection and monitoring requirements in addition to those already 739 listed in section 8.3 of [RFC5440]. 741 6.4. Verifying Correct Operation 743 Mechanisms defined in this document do not imply any new 744 verification requirements in addition to those already listed in 745 section 8.4 of [RFC5440] 747 6.5. Requirements on Other Protocols and Functional Components 749 The PCE Discovery mechanisms ([RFC5089] and [RFC5088]) may be used 750 to advertise WSON RWA path computation capabilities to PCCs. 752 6.6. Impact on Network Operation 754 Mechanisms defined in this document do not imply any new network 755 operation requirements in addition to those already listed in 756 section 8.6 of [RFC5440]. 758 7. Security Considerations 760 This document has no requirement for a change to the security models 761 within PCEP [PCEP]. However the additional information distributed 762 in order to address the RWA problem represents a disclosure of 763 network capabilities that an operator may wish to keep private. 764 Consideration should be given to securing this information. 766 8. IANA Considerations 768 IANA maintains a registry of PCEP parameters. IANA has made 769 allocations from the sub-registries as described in the following 770 sections. 772 8.1. New PCEP Object 774 As described in Section 4.1, a new PCEP Object is defined to carry 775 wavelength assignment related constraints. IANA is to allocate the 776 following from ''PCEP Objects'' sub-registry 777 (http://www.iana.org/assignments/pcep/pcep.xhtml#pcep-objects): 779 Object Class Name Object Reference 780 Value Type 781 --------------------------------------------------------- 782 TDB WA 1: Wavelength-Assignment [This.I-D] 784 8.2. New PCEP TLV: Wavelength Restriction Constraint TLV 786 As described in Sections 4.2, a new PCEP TLV is defined to indicate 787 wavelength restriction constraints. IANA is to allocate this new TLV 788 from the "PCEP TLV Type Indicators" subregistry 789 (http://www.iana.org/assignments/pcep/pcep.xhtml#pcep-tlv-type- 790 indicators). 792 Value Description Reference 793 --------------------------------------------------------- 794 TBD Wavelength Restriction [This.I-D] 795 Constraint 797 8.3. New PCEP TLV: Wavelength Allocation TLV 799 As described in Section 5, a new PCEP TLV is defined to indicate the 800 allocation of wavelength(s) by the PCE in response to a request by 801 the PCC. IANA is to allocate this new TLV from the "PCEP TLV Type 802 Indicators" subregistry 803 (http://www.iana.org/assignments/pcep/pcep.xhtml#pcep-tlv-type- 804 indicators). 806 Value Description Reference 807 --------------------------------------------------------- 808 TBD Wavelength Allocation [This.I-D] 810 8.4. New PCEP TLV: Optical Interface Class List TLV 812 As described in Section 4.3, a new PCEP TLV is defined to indicate 813 the allocation of wavelength(s) by the PCE in response to a request 814 by the PCC. IANA is to allocate this new TLV from the "PCEP TLV Type 815 Indicators" subregistry 816 (http://www.iana.org/assignments/pcep/pcep.xhtml#pcep-tlv-type- 817 indicators). 819 Value Description Reference 820 --------------------------------------------------------- 821 TBD Optical Interface [This.I-D] 822 Class List 824 8.5. New PCEP TLV: Client Signal TLV 826 As described in Section 4.3, a new PCEP TLV is defined to indicate 827 the allocation of wavelength(s) by the PCE in response to a request 828 by the PCC. IANA is to allocate this new TLV from the "PCEP TLV Type 829 Indicators" subregistry 830 (http://www.iana.org/assignments/pcep/pcep.xhtml#pcep-tlv-type- 831 indicators). 833 Value Description Reference 834 --------------------------------------------------------- 835 TBD Client Signal Field [This.I-D] 837 8.6. 839 8.7. New No-Path Reasons 841 As described in Section 5.2., a new bit flag are defined to be 842 carried in the Flags field in the NO-PATH-VECTOR TLV carried in the 843 NO-PATH Object. This flag, when set, indicates that no feasible 844 route was found that meets all the RWA constraints (e.g., wavelength 845 restriction, signal compatibility, etc.) associated with a RWA path 846 computation request. 848 IANA is to allocate this new bit flag from the "PCEP NO-PATH-VECTOR 849 TLV Flag Field" subregistry 850 (http://www.iana.org/assignments/pcep/pcep.xhtml#no-path-vector- 851 tlv). 853 Bit Description Reference 854 ----------------------------------------------------- 855 TBD No RWA constraints met [This.I-D] 857 8.8. New Error-Types and Error-Values 859 As described in Section 5.1, new PCEP error codes are defined for 860 WSON RWA errors. IANA is to allocate from the ''"PCEP-ERROR Object Error 861 Types and Values" sub-registry 862 (http://www.iana.org/assignments/pcep/pcep.xhtml#pcep-error-object). 864 Error- Meaning Error-Value Reference 865 Type 866 --------------------------------------------------------------- 868 TDB WSON RWA Error 1: Insufficient [This.I-D] 869 Memory 871 2: RWA computation {This.I-D] 872 Not supported 874 9. Acknowledgments 876 The authors would like to thank Adrian Farrel for many helpful 877 comments that greatly improved the contents of this draft. 879 This document was prepared using 2-Word-v2.0.template.dot. 881 10. References 883 10.1. Informative References 885 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 886 Requirement Levels", BCP 14, RFC 2119, March 1997. 888 [RFC3471] Berger, L., "Generalized Multi-Protocol Label Switching 889 (GMPLS) Signaling Functional Description", RFC 3471, 890 January 2003. 892 [RFC3473] Berger, L., Ed., "Generalized Multi-Protocol Label 893 Switching (GMPLS) Signaling Resource ReserVation Protocol- 894 Traffic Engineering (RSVP-TE) Extensions", RFC 3473, 895 January 2003. 897 [RFC3477] Kompella, K. and Y. Rekhter, "Signalling Unnumbered Links 898 in Resource ReSerVation Protocol - Traffic Engineering 899 (RSVP-TE)", RFC 3477, January 2003. 901 [RFC4003] Berger, L., "GMPLS Signaling Procedure for Egress Control", 902 RFC 4003, February 2005. 904 [RFC4655] Farrel, A., Vasseur, J., and J. Ash, "A Path Computation 905 Element (PCE)-Based Architecture", RFC 4655, August 2006. 907 [RFC4657] Ash, J. and J. Le Roux, "Path Computation Element (PCE) 908 Communication Protocol Generic Requirements", RFC 4657, 909 September 2006. 911 [RFC5440] Vasseur, JP., Ed. and JL. Le Roux, Ed., "Path Computation 912 Element (PCE) communication Protocol", RFC 5440, March 913 2009. 915 10.2. Normative References 917 [PCEP-GMPLS] Margaria, et al., ''PCEP extensions for GMPLS'', draft- 918 ietf-pce-gmpls-pcep-extensions, work in progress. 920 [RSVP-RO] Margaria, et al., ''LSP Attribute in ERO'', draft-margaria- 921 ccamp-lsp-attribute-ero, work in progress. 923 [PCEP-Layer] Oki, Takeda, Le Roux, and Farrel, ''Extensions to the 924 Path Computation Element communication Protocol (PCEP) for 925 Inter-Layer MPLS and GMPLS Traffic Engineering'', draft- 926 ietf-pce-inter-layer-ext, work in progress. 928 [RFC6163] Lee, Y. and Bernstein, G. (Editors), and W. Imajuku, 929 "Framework for GMPLS and PCE Control of Wavelength 930 Switched Optical Networks", RFC 6163, March 2011. 932 [RFC7449] Lee, Y., et. al., "PCEP Requirements for WSON Routing and 933 Wavelength Assignment", RFC 7449, February, 2015. 935 [RFC6205] Tomohiro, O. and D. Li, "Generalized Labels for Lambda- 936 Switching Capable Label Switching Routers", RFC 6205, 937 January, 2011. 939 [WSON-Sign] Bernstein et al,''Signaling Extensions for Wavelength 940 Switched Optical Networks'', draft-ietf-ccamp-wson- 941 signaling, work in progress. 943 [WSON-OSPF] Y. Lee, and G. Bernstein,''OSPF Enhancement for Signal 944 and Network Element Compatibility for Wavelength Switched 945 Optical Networks'',draft-ietf-ccamp-wson-signal- 946 compatibility-ospf, work in progress. 948 [RFC7446] Y. Lee, G. Bernstein. (Editors), ''Routing and Wavelength 949 Assignment Information Model for Wavelength Switched 950 Optical Networks'', RFC 7446, February 2015. 952 [RWA-Encode]Bernstein and Lee, ''Routing and Wavelength Assignment 953 Information Encoding for Wavelength Switched Optical 954 Networks'',draft-ietf-ccamp-rwa-wson-encode, work in 955 progress. 957 [GEN-Encode] Bernstein and Lee, ''General Network Element Constraint 958 Encoding for GMPLS Controlled Networks'',draft-ietf-ccamp- 959 general-constraint-encode, work in progress. 961 [WSON-Imp] Y. Lee, G. Bernstein, D. Li, G. Martinelli, "A Framework 962 for the Control of Wavelength Switched Optical Networks 963 (WSON) with Impairments", draft-ietf-ccamp-wson- 964 impairments, work in progress. 966 [RSVP-Imp] agraz, ''RSVP-TE Extensions in Support of Impairment Aware 967 Routing and Wavelength Assignment in Wavelength Switched 968 Optical Networks WSONs)'', draft-agraz-ccamp-wson- 969 impairment-rsvp, work in progress. 971 [OSPF-Imp] Bellagamba, et al., ''OSPF Extensions for Wavelength 972 Switched Optical Networks (WSON) with Impairments'',draft- 973 eb-ccamp-ospf-wson-impairments, work in progress. 975 11. Contributors 976 Authors' Addresses 978 Young Lee, Editor 979 Huawei Technologies 980 1700 Alma Drive, Suite 100 981 Plano, TX 75075, USA 982 Phone: (972) 509-5599 (x2240) 983 Email: leeyoung@huawei.com 985 Ramon Casellas, Editor 986 CTTC PMT Ed B4 Av. Carl Friedrich Gauss 7 987 08860 Castelldefels (Barcelona) 988 Spain 989 Phone: (34) 936452916 990 Email: ramon.casellas@cttc.es 992 Fatai Zhang 993 Huawei Technologies 994 Email: zhangfatai@huawei.com 996 Cyril Margaria 997 Nokia Siemens Networks 998 St Martin Strasse 76 999 Munich, 81541 1000 Germany 1001 Phone: +49 89 5159 16934 1002 Email: cyril.margaria@nsn.com 1004 Oscar Gonzalez de Dios 1005 Telefonica Investigacion y Desarrollo 1006 C/ Emilio Vargas 6 1007 Madrid, 28043 1008 Spain 1009 Phone: +34 91 3374013 1010 Email: ogondio@tid.es 1012 Greg Bernstein 1013 Grotto Networking 1014 Fremont, CA, USA 1015 Phone: (510) 573-2237 1016 Email: gregb@grotto-networking.com 1018 Intellectual Property Statement 1019 The IETF Trust takes no position regarding the validity or scope of 1020 any Intellectual Property Rights or other rights that might be 1021 claimed to pertain to the implementation or use of the technology 1022 described in any IETF Document or the extent to which any license 1023 under such rights might or might not be available; nor does it 1024 represent that it has made any independent effort to identify any 1025 such rights. 1027 Copies of Intellectual Property disclosures made to the IETF 1028 Secretariat and any assurances of licenses to be made available, or 1029 the result of an attempt made to obtain a general license or 1030 permission for the use of such proprietary rights by implementers or 1031 users of this specification can be obtained from the IETF on-line 1032 IPR repository at http://www.ietf.org/ipr 1034 The IETF invites any interested party to bring to its attention any 1035 copyrights, patents or patent applications, or other proprietary 1036 rights that may cover technology that may be required to implement 1037 any standard or specification contained in an IETF Document. Please 1038 address the information to the IETF at ietf-ipr@ietf.org. 1040 Disclaimer of Validity 1042 All IETF Documents and the information contained therein are 1043 provided on an "AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION 1044 HE/SHE REPRESENTS OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY, 1045 THE IETF TRUST AND THE INTERNET ENGINEERING TASK FORCE DISCLAIM ALL 1046 WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY 1047 WARRANTY THAT THE USE OF THE INFORMATION THEREIN WILL NOT INFRINGE 1048 ANY RIGHTS OR ANY IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS 1049 FOR A PARTICULAR PURPOSE. 1051 Acknowledgment 1053 Funding for the RFC Editor function is currently provided by the 1054 Internet Society.