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Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 1 Network Working Group Tomohiro Otani(Ed.) 2 Internet Draft KDDI 3 Updates: RFC3471 Dan Li(Ed.) 4 Category: Standards Track Huawei 6 Expires: June 2011 December 9, 2010 8 Generalized Labels for Lambda-Switching Capable Label Switching 9 Routers 11 draft-ietf-ccamp-gmpls-g-694-lambda-labels-09.txt 13 Status of this Memo 15 This Internet-Draft is submitted to IETF in full conformance with the 16 provisions of BCP 78 and BCP 79. 18 Internet-Drafts are working documents of the Internet Engineering 19 Task Force (IETF), its areas, and its working groups. Note that other 20 groups may also distribute working documents as Internet-Drafts. 22 Internet-Drafts are draft documents valid for a maximum of six months 23 and may be updated, replaced, or obsoleted by other documents at any 24 time. It is inappropriate to use Internet-Drafts as reference 25 material or to cite them other than as "work in progress." 27 The list of current Internet-Drafts can be accessed at 28 http://www.ietf.org/ietf/1id-abstracts.txt 30 The list of Internet-Draft Shadow Directories can be accessed at 31 http://www.ietf.org/shadow.html 33 This Internet-Draft will expire on June 9, 2011. 35 Copyright Notice 37 Copyright (c) 2010 IETF Trust and the persons identified as the 38 document authors. All rights reserved. 40 This document is subject to BCP 78 and the IETF Trust's Legal 41 Provisions Relating to IETF Documents 42 (http://trustee.ietf.org/license-info) in effect on the date of 43 publication of this document. Please review these documents carefully, 44 as they describe your rights and restrictions with respect to this 45 document. Code Components extracted from this document must include 46 Simplified BSD License text as described in Section 4.e of the Trust 47 Legal Provisions and are provided without warranty as described in 48 the Simplified BSD License. 50 Abstract 52 Technology in the optical domain is constantly evolving and as a 53 consequence new equipment providing lambda switching capability has 54 been developed and is currently being deployed. [RFC3471] has 55 defined that a wavelength label (section 3.2.1.1) "only has 56 significance between two neighbors" and global wavelength semantics 57 is not considered. In order to facilitate interoperability in a 58 network composed of next generation lambda switch-capable equipment, 59 this document defines a standard lambda label format, which is 60 compliant with both [G.694.1](DWDM-grid) or [G.694.2](CWDM-grid). 61 This document is a companion to the Generalized Multi-Protocol Label 62 Switching (GMPLS) signaling. It defines the label format when Lambda 63 Switching is requested in an all optical network. 65 Conventions used in this document 67 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 68 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this 69 document are to be interpreted as described in [RFC2119]. 71 Table of Contents 73 1. Introduction ................................................. 2 74 2. Assumed network model and related problem statement........... 3 75 3. Label Related Formats ........................................ 6 76 3.1. Wavelength Labels ....................................... 6 77 3.2. DWDM Wavelength Label ................................... 7 78 3.3. CWDM Wavelength Label ................................... 8 79 4. Security Considerations ..................................... 10 80 5. IANA Considerations ......................................... 10 81 6. Acknowledgments ............................................. 10 82 7. References .................................................. 10 83 7.1. Normative References ................................... 10 84 7.2. Informative References ................................. 11 85 8. Author's Address ............................................ 12 86 9. Appendix A. DWDM Example .................................... 13 87 10. Appendix B. CWDM Example ................................... 13 89 1. Introduction 91 As described in [RFC3945], Generalized MPLS (GMPLS) extends MPLS 92 from supporting only packet (Packet Switching Capable - PSC) 93 interfaces and switching to also include support for four new 94 classes of interfaces and switching: 96 o Layer-2 Switch Capable (L2SC) 98 o Time-Division Multiplex (TDM) 100 o Lambda Switch Capable (LSC) 102 o Fiber-Switch Capable (FSC). 104 A functional description of the extensions to MPLS signaling needed 105 to support new classes of interfaces and switching is provided in 106 [RFC3471]. 108 This document presents details that are specific to the use of GMPLS 109 with Lambda Switch Capable (LSC) equipment. Technologies such as 110 Reconfigurable Optical Add/Drop Multiplex (ROADM) and Wavelength 111 Cross-Connect (WXC) operate at the wavelength switching level. 112 [RFC3471] has defined that a wavelength label (section 3.2.1.1) "only 113 has significance between two neighbors" and global wavelength 114 semantics is not considered. In order to facilitate interoperability 115 in a network composed of lambda switch-capable equipment, this 116 document defines a standard lambda label format, which is compliant 117 with both [G.694.1](DWDM-grid) or [G.694.2](CWDM-grid). 119 2. Assumed network model and related problem statement 121 Figure 1 depicts an all-optically switched network consisting of 122 different vendor's optical network domains. Vendor A's network 123 consists of ROADM or WXC, and vendor B's network consists of number 124 of photonic cross-connect (PXC) and Dense wavelength division 125 multiplexing (DWDM) multiplexer & demultiplexer, otherwise both 126 vendors' networks might be based on the same technology. 128 In this case, the use of standardized wavelength label information is 129 quite significant to establish a wavelength-based LSP. It is also an 130 important constraint when conducting CSPF calculation for use by 131 Generalized Multi-Protocol Label Switching (GMPLS) RSVP-TE signaling, 132 [RFC3473]. The way the Constrained Shortest Path First (CSPF) is 133 performed is outside the scope of this document. 135 It is needless to say, a LSP must be appropriately provisioned 136 between a selected pair of ports not only within Domain A but also 137 over multiple domains satisfying wavelength constraints. 139 Figure 2 illustrates in detail the interconnection between Domain A 140 and Domain B. 142 | 143 Domain A (or Vendor A) | Domain B (or Vendor B) 144 | 145 Node-1 Node-2 | Node-6 Node-7 146 +--------+ +--------+ | +-------+ +-+ +-+ +-------+ 147 | ROADM | | ROADM +---|------+ PXC +-+D| |D+-+ PXC | 148 | or WXC +========+ or WXC +---|------+ +-+W+=====+W+-+ | 149 | (LSC) | | (LSC) +---|------+ (LSC) +-+D| |D+-+ (LSC) | 150 +--------+ +--------+ | | +-|M| |M+-+ | 151 || || | +++++++++ +-+ +-+ +++++++++ 152 || Node-3 || | ||||||| ||||||| 153 || +--------+ || | +++++++++ +++++++++ 154 ||===| WXC +===|| | | DWDM | | DWDM | 155 | (LSC) | | +--++---+ +--++---+ 156 ||===+ +===|| | || || 157 || +--------+ || | +--++---+ +--++---+ 158 || || | | DWDM | | DWDM | 159 +--------+ +--------+ | +++++++++ +++++++++ 160 | ROADM | | ROADM | | ||||||| ||||||| 161 | or WXC +========+ or WXC +=+ | +-+ +++++++++ +-+ +-+ +++++++++ 162 | (LSC) | | (LSC) | | | |D|-| PXC +-+D| |D+-+ PXC | 163 +--------+ +--------+ +=|==+W|-| +-+W+=====+W+-+ | 164 Node-4 Node-5 | |D|-| (LSC) +-+D| |D+-+ (LSC) | 165 | |M|-| +-+M| |M+-+ | 166 | +-+ +-------+ +-+ +-+ +-------+ 167 | Node-8 Node-9 169 Figure 1 Wavelength-based network model 171 +-------------------------------------------------------------+ 172 | Domain A | Domain B | 173 | | | 174 | +---+ lambda 1 | +---+ | 175 | | |---------------|---------| | | 176 | WDM | N | lambda 2 | | N | WDM | 177 | =====| O |---------------|---------| O |===== | 178 | O | D | . | | D | O | 179 | T WDM | E | . | | E | WDM T | 180 | H =====| 2 | lambda n | | 6 |===== H | 181 | E | |---------------|---------| | E | 182 | R +---+ | +---+ R | 183 | | | 184 | N +---+ | +---+ N | 185 | O | | | | | O | 186 | D WDM | N | | | N | WDM D | 187 | E =====| O | WDM | | O |===== E | 188 | S | D |=========================| D | S | 189 | WDM | E | | | E | WDM | 190 | =====| 5 | | | 8 |===== | 191 | | | | | | | 192 | +---+ | +---+ | 193 +-------------------------------------------------------------+ 195 Figure 2 Interconnecting details between two domains 197 In the scenario of Figure 1, consider the setting up of a 198 bidirectional LSP from ingress switch 1 to egress switch 9 using 199 GMPLS RSVP-TE. In order to satisfy wavelength continuity constraint, 200 a fixed wavelength (lambda 1) needs to be used in domain A and domain 201 B. A Path message will be used for signaling. The Path message will 202 contain the Upstream_Label object and a Label_Set object; both 203 containing the same value. The Label_Set object is made by only one 204 sub channel that must be same as the Upstream_Label object. The Path 205 setup will continue downstream to switch 9 by configuring each lambda 206 switch based on the wavelength label. If a node has a tunable 207 wavelength transponder, the tuning wavelength is considered as a part 208 of wavelength switching operation. 210 Not using a standardized label would add undue burden on the operator 211 to enforce policy as each manufacturer may decide on a different 212 representation and therefore each domain may have its own label 213 formats. Moreover, manual provisioning may lead to misconfiguration 214 if domain-specific labels are used. 216 Therefore, a wavelength label should be standardized in order to 217 allow interoperability between multiple domains; otherwise 218 appropriate existing labels are identified in support of wavelength 219 availability. As identical wavelength information, the ITU-T 220 frequency grid specified in [G.694.1] for Dense WDM (DWDM) and 221 wavelength information in [G.694.2] for Coarse WDM (CWDM) are used by 222 LSRs and should be followed as a wavelength label. 224 3. Label Related Formats 226 To deal with the widening scope of MPLS into the optical and time 227 domains, several new forms of "label" have been defined in [RFC3471]. 228 This section contains a definition of a Wavelength label based on 229 [G.694.1] or [G.694.2] for use by LSC LSRs. 231 3.1. Wavelength Labels 233 In section 3.2.1.1 of [RFC3471], a Wavelength label is defined to 234 have significance between two neighbors, and the receiver may need to 235 convert the received value into a value that has local significance. 237 LSC equipment uses multiple wavelengths controlled by a single 238 control channel. In a case, the label indicates the wavelength to be 239 used for the LSP. This document defines a standardize wavelength 240 label format. As an example of wavelength values, the reader is 241 referred to [G.694.1] which lists the frequencies from the ITU-T DWDM 242 frequency grid. The same can be done for CWDM technology by using 243 the wavelength defined in [G.694.2]. 245 Since the ITU-T DWDM grid is based on nominal central frequencies, we 246 need to indicate the appropriate table, the channel spacing in the 247 grid and a value n that allows the calculation of the frequency. That 248 value can be positive or negative. 250 The frequency is calculated as such in [G.694.1]: 252 Frequency (THz) = 193.1 THz + n * channel spacing (THz) 254 Where "n" is a two's-complement integer (positive, negative or 0) and 255 "channel spacing" is defined to be 0.0125, 0.025, 0.05 or 0.1 THz. 256 When wider channel spacing such as 0.2 THz is utilized, the 257 combination of narrower channel spacing and the value "n" can provide 258 proper frequency with that channel spacing. Channel spacing is not 259 utilized to indicate the LSR capability but only to specify a 260 frequency in signaling. 262 For the other example of the case of the ITU-T CWDM grid, the spacing 263 between different channels was defined to be 20nm, so we need to pass 264 the wavelength value in nanometers(nm) in this case. Examples of CWDM 265 wavelengths are 1471, 1491, etc. nm. 267 The wavelength is calculated as follows 269 Wavelength (nm) = 1471 nm + n * 20 nm 271 Where "n" is a two's-complement integer (positive, negative or 0). 272 The grids listed in [G.694.1] and [G.694.2] are not numbered and 273 change with the changing frequency spacing as technology advances, so 274 an index is not appropriate in this case. 276 3.2. DWDM Wavelength Label 278 For the case of lambda switching (LSC) of DWDM, the information 279 carried in a Wavelength label is: 281 0 1 2 3 282 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 1 283 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 284 |Grid | C.S | Identifier | n | 285 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 287 (1) Grid: 3 bits 289 The value for grid is set to 1 for ITU-T DWDM Grid as defined in 290 [G.694.1]. 292 +----------+---------+ 293 | Grid | Value | 294 +----------+---------+ 295 | Reserved | 0 | 296 +----------+---------+ 297 |ITU-T DWDM| 1 | 298 +----------+---------+ 299 |ITU-T CWDM| 2 | 300 +----------+---------+ 301 |Future use| 3 - 7 | 302 +----------+---------+ 304 (2) C.S.(channel spacing): 4 bits 306 DWDM channel spacing is defined as follows. 308 +----------+---------+ 309 | C.S(GHz) | Value | 310 +----------+---------+ 311 | Reserved | 0 | 312 +----------+---------+ 313 | 100 | 1 | 314 +----------+---------+ 315 | 50 | 2 | 316 +----------+---------+ 317 | 25 | 3 | 318 +----------+---------+ 319 | 12.5 | 4 | 320 +----------+---------+ 321 |Future use| 5 - 15 | 322 +----------+---------+ 324 (3) Identifier: 9 bits 326 The identifier field is a per-node assigned and scoped value. This 327 field MAY change on a per-hop basis. In all cases but one, a node MAY 328 select any value, including zero (0), for this field. Once selected, 329 the value MUST NOT change until the LSP is torn down and the value 330 MUST be used in all LSP related messages, e.g., in Resv messages and 331 label RRO subobjects. The sole special case occurs when this label 332 format is used in a label ERO subobject. In this case, the special 333 value of zero (0) means that the referenced node MAY assign any 334 Identifier field value, including zero (0), when establishing the 335 corresponding LSP. 337 (4) n: 16 bits 339 n is a two's-complement integer to take either a negative, zero or a 340 positive value. The value used to compute the frequency as shown 341 above. 343 3.3. CWDM Wavelength Label 345 For the case of lambda switching (LSC) of CWDM, the information 346 carried in a Wavelength label is: 348 0 1 2 3 349 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 1 350 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 351 |Grid | C.S | Identifier | n | 352 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 354 The structure of the label in the case of CWDM is the same as that of 355 DWDM case. 357 (1) Grid: 3 bits 359 The value for grid is set to 2 for ITU-T CWDM Grid as defined in 360 [G.694.2]. 362 +----------+---------+ 363 | Grid | Value | 364 +----------+---------+ 365 | Reserved | 0 | 366 +----------+---------+ 367 |ITU-T DWDM| 1 | 368 +----------+---------+ 369 |ITU-T CWDM| 2 | 370 +----------+---------+ 371 |Future use| 3 - 7 | 372 +----------+---------+ 374 (2) C.S.(channel spacing): 4 bits 376 CWDM channel spacing is defined as follows. 378 +----------+---------+ 379 | C.S(nm) | Value | 380 +----------+---------+ 381 | Reserved | 0 | 382 +----------+---------+ 383 | 20 | 1 | 384 +----------+---------+ 385 |Future use| 2 - 15 | 386 +----------+---------+ 388 (3) Identifier: 9 bits 390 The identifier field is a per-node assigned and scoped value. This 391 field MAY change on a per-hop basis. In all cases but one, a node MAY 392 select any value, including zero (0), for this field. Once selected, 393 the value MUST NOT change until the LSP is torn down and the value 394 MUST be used in all LSP related messages, e.g., in Resv messages and 395 label RRO subobjects. The sole special case occurs when this label 396 format is used in a label ERO subobject. In this case, the special 397 value of zero (0) means that the referenced node MAY assign any 398 Identifier field value, including zero (0), when establishing the 399 corresponding LSP. 401 (4) n: 16 bits 403 n is a two's-complement integer. The value used to compute the 404 wavelength as shown above. 406 We do not need to define a new type as the information stored is 407 either a port label or a wavelength label. Only the wavelength label 408 as above needs to be defined. 410 4. Security Considerations 412 This document introduces no new security considerations to [RFC3473]. 413 For a general discussion on MPLS and GMPLS related security issues, 414 see the MPLS/GMPLS security framework [RFC5920]. 416 5. IANA Considerations 418 This document has no actions for IANA. 420 6. Acknowledgments 422 The authors would like to thank Adrian Farrel, Lou Berger, Lawrence 423 Mao, Zafar Ali and Daniele Ceccarelli for the discussion and their 424 comments. 426 7. References 428 7.1. Normative References 430 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 431 Requirement Levels", BCP 14, RFC 2119, March 1997. 433 [RFC3209] Awduche, D., Berger, L., Gan, D., Li, T., Srinivasan, V., 434 and G. Swallow, "RSVP-TE: Extensions to RSVP for LSP 435 Tunnels", RFC 3209, December 2001. 437 [RFC3471] Berger, L., "Generalized Multi-Protocol Label Switching 438 (MPLS) Signaling Functional Description", RFC 3471, January 439 2003. 441 [RFC3473] Berger, L., "Generalized Multi-Protocol Label Switching 442 (MPLS) Signaling - Resource ReserVation Protocol Traffic 443 Engineering (RSVP-TE) Extensions", RFC 3473, January 2003. 445 [RFC3945] Mannie, E., Ed., "Generalized Multiprotocol Label Switching 446 (GMPLS) Architecture", RFC 3945, October 2004. 448 7.2. Informative References 450 [G.694.1] ITU-T Recommendation G.694.1, "Spectral grids for WDM 451 applications: DWDM frequency grid", June 2002. 453 [G.694.2] ITU-T Recommendation G.694.2, "Spectral grids for WDM 454 applications: CWDM wavelength grid", December 2003. 456 [RFC5920] Fang, L., "Security Framework for MPLS and GMPLS 457 Networks", RFC 5920, July 2010. 459 8. Author's Address 461 Tomohiro Otani 462 KDDI Corporation 463 2-3-2 Nishishinjuku Shinjuku-ku 464 Tokyo, 163-8003, Japan 465 Phone: +81-3-3347-6006 466 Email: tm-otani@kddi.com 468 Richard Rabbat 469 Google, Inc. 470 1600 Amphitheatre Pkwy 471 Mountain View, CA 94043 472 Email: rabbat@alum.mit.edu 474 Sidney Shiba 475 Email: sidney.shiba@yahoo.com 477 Hongxiang Guo 478 Email: hongxiang.guo@gmail.com 480 Keiji Miyazaki 481 Fujitsu Laboratories Ltd 482 4-1-1 Kotanaka Nakahara-ku, 483 Kawasaki Kanagawa, 211-8588, Japan 484 Phone: +81-44-754-2765 485 Email: miyazaki.keiji@jp.fujitsu.com 487 Diego Caviglia 488 Ericsson 489 16153 Genova Cornigliano, ITALY 490 Phone: +390106003736 491 Email: diego.caviglia@ericsson.com 493 Dan Li 494 Huawei Technologies 495 F3-5-B R&D Center, Huawei Base, 496 Shenzhen 518129 China 497 Phone: +86 755-289-70230 498 Email: danli@huawei.com 500 Takehiro Tsuritani 501 KDDI R&D Laboratories Inc. 502 2-1-15 Ohara Fujimino-shi 503 Saitama, 356-8502, Japan 504 Phone: +81-49-278-7806 505 Email: tsuri@kddilabs.jp 507 9. Appendix A. DWDM Example 509 Considering the network displayed in figure 1 it is possible to show 510 an example of LSP set up using the lambda labels. 512 Node 1 receives the request for establishing an LSP from itself to 513 Node 9. The ITU-T grid to be used is the DWDM one, the channel 514 spacing is 50Ghz and the wavelength to be used is 193,35 THz. 516 Node 1 signals the LSP via a Path message including a Wavelength 517 Label structured as defined in section 4.2: 519 0 1 2 3 520 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 1 521 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 522 |Grid | C.S | Identifier | n | 523 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 525 Where: 527 Grid = 1 : ITU-T DWDM grid 529 C.S. = 2 : 50 GHz channel spacing 531 n = 5 : 533 Frequency (THz) = 193.1 THz + n * channel spacing (THz) 535 193.35 (THz) = 193.1 (THz) + n* 0.05 (THz) 537 n = (193.35-193.1)/0.05 = 5 539 10. Appendix B. CWDM Example 541 The network displayed in figure 1 can be used also to display an 542 example of signaling using the Wavelength Label in a CWDM 543 environment. 545 This time the signaling of an LSP from Node 4 to Node 7 is 546 considered. Such LSP exploits the CWDM ITU-T grid with a 20nm 547 channel spacing and is to established using wavelength equal to 1331 548 nm. 550 Node 4 signals the LSP via a Path message including a Wavelength 551 Label structured as defined in section 4.3: 553 0 1 2 3 554 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 1 555 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 556 |Grid | C.S | Identifier | n | 557 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 559 Where: 561 Grid = 2 : ITU-T CWDM grid 563 C.S. = 1 : 20 nm channel spacing 565 n = -7 : 567 Wavelength (nm) = 1471 nm + n * 20 nm 569 1331 (nm) = 1471 (nm) + n * 20 nm 571 n = (1331-1471)/20 = -7