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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: 3471(if approved) Dan Li(Ed.) 4 Category: Standards Track Huawei 6 Expires: June 2011 December 13, 2010 8 Generalized Labels for Lambda-Switching Capable Label Switching 9 Routers 11 draft-ietf-ccamp-gmpls-g-694-lambda-labels-10.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 13, 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 44 carefully, as they describe your rights and restrictions with respect 45 to this document. Code Components extracted from this document must 46 include Simplified BSD License text as described in Section 4.e of 47 the Trust Legal Provisions and are provided without warranty as 48 described in the Simplified BSD License. 50 This document may contain material from IETF Documents or IETF 51 Contributions published or made publicly available before November 52 10, 2008. The person(s) controlling the copyright in some of this 53 material may not have granted the IETF Trust the right to allow 54 modifications of such material outside the IETF Standards Process. 55 Without obtaining an adequate license from the person(s) controlling 56 the copyright in such materials, this document may not be modified 57 outside the IETF Standards Process, and derivative works of it may 58 not be created outside the IETF Standards Process, except to format 59 it for publication as an RFC or to translate it into languages other 60 than English. 62 Abstract 64 Technology in the optical domain is constantly evolving and as a 65 consequence new equipment providing lambda switching capability has 66 been developed and is currently being deployed. 68 Generalized MPLS (GMPLS) is a family of protocols that can be used 69 to operate networks built from a range of technologies including 70 wavelength (or lambda) switching. For this purpose, GMPLS defined 71 that a wavelength label only has significance between two neighbors 72 and global wavelength semantics are not considered. 74 In order to facilitate interoperability in a network composed of 75 next generation lambda switch-capable equipment, this document 76 defines a standard lambda label format that is compliant with Dense 77 Wavelength Division Multiplexing and Coarse Wavelength Division 78 Multiplexing grids defined by the International Telecommunication 79 Union Telecommunication Standardization Sector. The label format 80 defined in this document can be used in GMPLS signaling and routing 81 protocols. 83 Conventions used in this document 85 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 86 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this 87 document are to be interpreted as described in [RFC2119]. 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](Dense Wavelength Division Multiplexing (DWDM)- 118 grid) or [G.694.2](Coarse Wavelength Division Multiplexing (CWDM)- 119 grid). 121 2. Assumed Network Model and Related Problem Statement 123 Figure 1 depicts an all-optically switched network consisting of 124 different vendors' optical network domains. Vendor A's network 125 consists of ROADM or WXC, and vendor B's network consists of a number 126 of photonic cross-connect (PXC) and DWDM multiplexer & demultiplexer, 127 otherwise both vendors' networks might be based on the same 128 technology. 130 In this case, the use of standardized wavelength label information is 131 quite significant to establish a wavelength-based LSP. It is also an 132 important constraint when conducting CSPF calculation for use by 133 Generalized Multi-Protocol Label Switching (GMPLS) RSVP-TE signaling, 134 [RFC3473]. The way the Constrained Shortest Path First (CSPF) is 135 performed is outside the scope of this document. 137 It is needless to say, an LSP must be appropriately provisioned 138 between a selected pair of ports not only within Domain A but also 139 over multiple domains satisfying wavelength constraints. 141 Figure 2 illustrates in detail the interconnection between Domain A 142 and Domain B. 144 | 145 Domain A (or Vendor A) | Domain B (or Vendor B) 146 | 147 Node-1 Node-2 | Node-6 Node-7 148 +--------+ +--------+ | +-------+ +-+ +-+ +-------+ 149 | ROADM | | ROADM +---|------+ PXC +-+D| |D+-+ PXC | 150 | or WXC +========+ or WXC +---|------+ +-+W+=====+W+-+ | 151 | (LSC) | | (LSC) +---|------+ (LSC) +-+D| |D+-+ (LSC) | 152 +--------+ +--------+ | | +-|M| |M+-+ | 153 || || | +++++++++ +-+ +-+ +++++++++ 154 || Node-3 || | ||||||| ||||||| 155 || +--------+ || | +++++++++ +++++++++ 156 ||===| WXC +===|| | | DWDM | | DWDM | 157 | (LSC) | | +--++---+ +--++---+ 158 ||===+ +===|| | || || 159 || +--------+ || | +--++---+ +--++---+ 160 || || | | DWDM | | DWDM | 161 +--------+ +--------+ | +++++++++ +++++++++ 162 | ROADM | | ROADM | | ||||||| ||||||| 163 | or WXC +========+ or WXC +=+ | +-+ +++++++++ +-+ +-+ +++++++++ 164 | (LSC) | | (LSC) | | | |D|-| PXC +-+D| |D+-+ PXC | 165 +--------+ +--------+ +=|==+W|-| +-+W+=====+W+-+ | 166 Node-4 Node-5 | |D|-| (LSC) +-+D| |D+-+ (LSC) | 167 | |M|-| +-+M| |M+-+ | 168 | +-+ +-------+ +-+ +-+ +-------+ 169 | Node-8 Node-9 171 Figure 1 Wavelength-based network model 173 +-------------------------------------------------------------+ 174 | Domain A | Domain B | 175 | | | 176 | +---+ lambda 1 | +---+ | 177 | | |---------------|---------| | | 178 | WDM | N | lambda 2 | | N | WDM | 179 | =====| O |---------------|---------| O |===== | 180 | O | D | . | | D | O | 181 | T WDM | E | . | | E | WDM T | 182 | H =====| 2 | lambda n | | 6 |===== H | 183 | E | |---------------|---------| | E | 184 | R +---+ | +---+ R | 185 | | | 186 | N +---+ | +---+ N | 187 | O | | | | | O | 188 | D WDM | N | | | N | WDM D | 189 | E =====| O | WDM | | O |===== E | 190 | S | D |=========================| D | S | 191 | WDM | E | | | E | WDM | 192 | =====| 5 | | | 8 |===== | 193 | | | | | | | 194 | +---+ | +---+ | 195 +-------------------------------------------------------------+ 197 Figure 2 Interconnecting details between two domains 199 In the scenario of Figure 1, consider the setting up of a 200 bidirectional LSP from ingress switch 1 to egress switch 9 using 201 GMPLS RSVP-TE. In order to satisfy wavelength continuity constraint, 202 a fixed wavelength (lambda 1) needs to be used in domain A and domain 203 B. A Path message will be used for signaling. The Path message will 204 contain the Upstream_Label object and a Label_Set object; both 205 containing the same value. The Label_Set object is made by only one 206 sub channel that must be same as the Upstream_Label object. The Path 207 setup will continue downstream to switch 9 by configuring each lambda 208 switch based on the wavelength label. If a node has a tunable 209 wavelength transponder, the tuning wavelength is considered as a part 210 of wavelength switching operation. 212 Not using a standardized label would add undue burden on the operator 213 to enforce policy as each manufacturer may decide on a different 214 representation and therefore each domain may have its own label 215 formats. Moreover, manual provisioning may lead to misconfiguration 216 if domain-specific labels are used. 218 Therefore, a wavelength label should be standardized in order to 219 allow interoperability between multiple domains; otherwise 220 appropriate existing labels are identified in support of wavelength 221 availability. As identical wavelength information, the ITU-T 222 frequency grid specified in [G.694.1] for DWDM and wavelength 223 information in [G.694.2] for CWDM are used by Label Switching Routers 224 (LSRs) and should be followed as a wavelength label. 226 3. Label Related Formats 228 To deal with the widening scope of MPLS into the optical and time 229 domains, several new forms of "label" have been defined in [RFC3471]. 230 This section contains a definition of a Wavelength label based on 231 [G.694.1] or [G.694.2] for use by LSC LSRs. 233 3.1. Wavelength Labels 235 In section 3.2.1.1 of [RFC3471], a Wavelength label is defined to 236 have significance between two neighbors, and the receiver may need to 237 convert the received value into a value that has local significance. 239 We do not need to define a new type as the information stored is 240 either a port label or a wavelength label. Only the wavelength label 241 as below needs to be defined. 243 LSC equipment uses multiple wavelengths controlled by a single 244 control channel. In a case, the label indicates the wavelength to be 245 used for the LSP. This document defines a standardize wavelength 246 label format. As an example of wavelength values, the reader is 247 referred to [G.694.1] which lists the frequencies from the ITU-T DWDM 248 frequency grid. The same can be done for CWDM technology by using 249 the wavelength defined in [G.694.2]. 251 Since the ITU-T DWDM grid is based on nominal central frequencies, we 252 need to indicate the appropriate table, the channel spacing in the 253 grid and a value n that allows the calculation of the frequency. That 254 value can be positive or negative. 256 The frequency is calculated as such in [G.694.1]: 258 Frequency (THz) = 193.1 THz + n * channel spacing (THz) 260 Where "n" is a two's-complement integer (positive, negative or 0) and 261 "channel spacing" is defined to be 0.0125, 0.025, 0.05 or 0.1 THz. 262 When wider channel spacing such as 0.2 THz is utilized, the 263 combination of narrower channel spacing and the value "n" can provide 264 proper frequency with that channel spacing. Channel spacing is not 265 utilized to indicate the LSR capability but only to specify a 266 frequency in signaling. 268 For the other example of the case of the ITU-T CWDM grid, the spacing 269 between different channels was defined to be 20nm, so we need to pass 270 the wavelength value in nanometers(nm) in this case. Examples of CWDM 271 wavelengths are 1471, 1491, etc. nm. 273 The wavelength is calculated as follows 275 Wavelength (nm) = 1471 nm + n * 20 nm 277 Where "n" is a two's-complement integer (positive, negative or 0). 278 The grids listed in [G.694.1] and [G.694.2] are not numbered and 279 change with the changing frequency spacing as technology advances, so 280 an index is not appropriate in this case. 282 3.2. DWDM Wavelength Label 284 For the case of lambda switching (LSC) of DWDM, the information 285 carried in a Wavelength label is: 287 0 1 2 3 288 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 1 289 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 290 |Grid | C.S | Identifier | n | 291 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 293 (1) Grid: 3 bits 295 The value for grid is set to 1 for ITU-T DWDM Grid as defined in 296 [G.694.1]. 298 +----------+---------+ 299 | Grid | Value | 300 +----------+---------+ 301 | Reserved | 0 | 302 +----------+---------+ 303 |ITU-T DWDM| 1 | 304 +----------+---------+ 305 |ITU-T CWDM| 2 | 306 +----------+---------+ 307 |Future use| 3 - 7 | 308 +----------+---------+ 310 (2) C.S.(channel spacing): 4 bits 312 DWDM channel spacing is defined as follows. 314 +----------+---------+ 315 | C.S(GHz) | Value | 316 +----------+---------+ 317 | Reserved | 0 | 318 +----------+---------+ 319 | 100 | 1 | 320 +----------+---------+ 321 | 50 | 2 | 322 +----------+---------+ 323 | 25 | 3 | 324 +----------+---------+ 325 | 12.5 | 4 | 326 +----------+---------+ 327 |Future use| 5 - 15 | 328 +----------+---------+ 330 (3) Identifier: 9 bits 332 The identifier field is a per-node assigned and scoped value. This 333 field MAY change on a per-hop basis. In all cases but one, a node MAY 334 select any value, including zero (0), for this field. Once selected, 335 the value MUST NOT change until the LSP is torn down and the value 336 MUST be used in all LSP related messages, e.g., in Resv messages and 337 label RRO subobjects. The sole special case occurs when this label 338 format is used in a label ERO subobject. In this case, the special 339 value of zero (0) means that the referenced node MAY assign any 340 Identifier field value, including zero (0), when establishing the 341 corresponding LSP. 343 (4) n: 16 bits 345 n is a two's-complement integer to take either a negative, zero or a 346 positive value. The value used to compute the frequency as shown 347 above. 349 3.3. CWDM Wavelength Label 351 For the case of lambda switching (LSC) of CWDM, the information 352 carried in a Wavelength label is: 354 0 1 2 3 355 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 1 356 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 357 |Grid | C.S | Identifier | n | 358 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 360 The structure of the label in the case of CWDM is the same as that of 361 DWDM case. 363 (1) Grid: 3 bits 365 The value for grid is set to 2 for ITU-T CWDM Grid as defined in 366 [G.694.2]. 368 +----------+---------+ 369 | Grid | Value | 370 +----------+---------+ 371 | Reserved | 0 | 372 +----------+---------+ 373 |ITU-T DWDM| 1 | 374 +----------+---------+ 375 |ITU-T CWDM| 2 | 376 +----------+---------+ 377 |Future use| 3 - 7 | 378 +----------+---------+ 380 (2) C.S.(channel spacing): 4 bits 382 CWDM channel spacing is defined as follows. 384 +----------+---------+ 385 | C.S(nm) | Value | 386 +----------+---------+ 387 | Reserved | 0 | 388 +----------+---------+ 389 | 20 | 1 | 390 +----------+---------+ 391 |Future use| 2 - 15 | 392 +----------+---------+ 394 (3) Identifier: 9 bits 396 The identifier field is a per-node assigned and scoped value. This 397 field MAY change on a per-hop basis. In all cases but one, a node MAY 398 select any value, including zero (0), for this field. Once selected, 399 the value MUST NOT change until the LSP is torn down and the value 400 MUST be used in all LSP related messages, e.g., in Resv messages and 401 label RRO subobjects. The sole special case occurs when this label 402 format is used in a label ERO subobject. In this case, the special 403 value of zero (0) means that the referenced node MAY assign any 404 Identifier field value, including zero (0), when establishing the 405 corresponding LSP. 407 (4) n: 16 bits 409 n is a two's-complement integer. The value used to compute the 410 wavelength as shown above. 412 4. Security Considerations 414 This document introduces no new security considerations to [RFC3471] 415 and [RFC3473]. For a general discussion on MPLS and GMPLS related 416 security issues, see the MPLS/GMPLS security framework [RFC5920]. 418 5. IANA Considerations 420 IANA maintains the "Generalized Multi-Protocol Label Switching 421 (GMPLS) Signaling Parameters" registry. IANA is requested to add 422 three new subregistries to track the codepoints (Grid and C.S.) used 423 in the DWDM and CWDM Wavelength Labels, which are described in the 424 following sections. 426 5.1. Grid Subregistry 428 Initial entries in this subregistry are as follows: 430 Value Grid Reference 431 ----- ------------------------- ---------- 432 0 Reserved [This.I-D] 433 1 ITU-T DWDM [This.I-D] 434 2 ITU-T CWDM [This.I-D] 435 3-7 Not assigned at this time [This.I-D] 437 New values are assigned according to Standards Action. 439 5.2. DWDM Channel Spacing Subregistry 441 Initial entries in this subregistry are as follows: 443 Value Channel Spacing (GHz) Reference 444 ----- ------------------------- ---------- 445 0 Reserved [This.I-D] 446 1 100 [This.I-D] 447 2 50 [This.I-D] 448 3 25 [This.I-D] 449 4 12.5 [This.I-D] 450 5-15 Not assigned at this time [This.I-D] 452 New values are assigned according to Standards Action. 454 5.3. CWDM Channel Spacing Subregistry 456 Initial entries in this subregistry are as follows: 458 Value Channel Spacing (nm) Reference 459 ----- ------------------------- ---------- 460 0 Reserved [This.I-D] 461 1 20 [This.I-D] 462 2-15 Not assigned at this time [This.I-D] 464 New values are assigned according to Standards Action. 466 6. Acknowledgments 468 The authors would like to thank Adrian Farrel, Lou Berger, Lawrence 469 Mao, Zafar Ali and Daniele Ceccarelli for the discussion and their 470 comments. 472 7. References 474 7.1. Normative References 476 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 477 Requirement Levels", BCP 14, RFC 2119, March 1997. 479 [RFC3471] Berger, L., "Generalized Multi-Protocol Label Switching 480 (MPLS) Signaling Functional Description", RFC 3471, January 481 2003. 483 [RFC3473] Berger, L., "Generalized Multi-Protocol Label Switching 484 (MPLS) Signaling - Resource ReserVation Protocol Traffic 485 Engineering (RSVP-TE) Extensions", RFC 3473, January 2003. 487 [RFC3945] Mannie, E., Ed., "Generalized Multiprotocol Label Switching 488 (GMPLS) Architecture", RFC 3945, October 2004. 490 7.2. Informative References 492 [G.694.1] ITU-T Recommendation G.694.1, "Spectral grids for WDM 493 applications: DWDM frequency grid", June 2002. 495 [G.694.2] ITU-T Recommendation G.694.2, "Spectral grids for WDM 496 applications: CWDM wavelength grid", December 2003. 498 [RFC5920] Fang, L., "Security Framework for MPLS and GMPLS 499 Networks", RFC 5920, July 2010. 501 8. Authors' Address 503 Tomohiro Otani 504 KDDI Corporation 505 2-3-2 Nishishinjuku Shinjuku-ku 506 Tokyo, 163-8003, Japan 507 Phone: +81-3-3347-6006 508 Email: tm-otani@kddi.com 510 Richard Rabbat 511 Google, Inc. 512 1600 Amphitheatre Pkwy 513 Mountain View, CA 94043 514 Email: rabbat@alum.mit.edu 516 Sidney Shiba 517 Email: sidney.shiba@att.net 519 Hongxiang Guo 520 Email: hongxiang.guo@gmail.com 522 Keiji Miyazaki 523 Fujitsu Laboratories Ltd 524 4-1-1 Kotanaka Nakahara-ku, 525 Kawasaki Kanagawa, 211-8588, Japan 526 Phone: +81-44-754-2765 527 Email: miyazaki.keiji@jp.fujitsu.com 529 Diego Caviglia 530 Ericsson 531 16153 Genova Cornigliano, ITALY 532 Phone: +390106003736 533 Email: diego.caviglia@ericsson.com 535 Dan Li 536 Huawei Technologies 537 F3-5-B R&D Center, Huawei Base, 538 Shenzhen 518129 China 539 Phone: +86 755-289-70230 540 Email: danli@huawei.com 542 Takehiro Tsuritani 543 KDDI R&D Laboratories Inc. 544 2-1-15 Ohara Fujimino-shi 545 Saitama, 356-8502, Japan 546 Phone: +81-49-278-7806 547 Email: tsuri@kddilabs.jp 549 9. Appendix A. DWDM Example 551 Considering the network displayed in figure 1 it is possible to show 552 an example of LSP set up using the lambda labels. 554 Node 1 receives the request for establishing an LSP from itself to 555 Node 9. The ITU-T grid to be used is the DWDM one, the channel 556 spacing is 50Ghz and the wavelength to be used is 193,35 THz. 558 Node 1 signals the LSP via a Path message including a Wavelength 559 Label structured as defined in section 4.2: 561 0 1 2 3 562 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 1 563 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 564 |Grid | C.S | Identifier | n | 565 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 567 Where: 569 Grid = 1 : ITU-T DWDM grid 571 C.S. = 2 : 50 GHz channel spacing 573 n = 5 : 575 Frequency (THz) = 193.1 THz + n * channel spacing (THz) 577 193.35 (THz) = 193.1 (THz) + n* 0.05 (THz) 579 n = (193.35-193.1)/0.05 = 5 581 10. Appendix B. CWDM Example 583 The network displayed in figure 1 can be used also to display an 584 example of signaling using the Wavelength Label in a CWDM 585 environment. 587 This time the signaling of an LSP from Node 4 to Node 7 is 588 considered. Such LSP exploits the CWDM ITU-T grid with a 20nm channel 589 spacing and is to established using wavelength equal to 1331 nm. 591 Node 4 signals the LSP via a Path message including a Wavelength 592 Label structured as defined in section 4.3: 594 0 1 2 3 595 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 1 596 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 597 |Grid | C.S | Identifier | n | 598 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 600 Where: 602 Grid = 2 : ITU-T CWDM grid 604 C.S. = 1 : 20 nm channel spacing 606 n = -7 : 608 Wavelength (nm) = 1471 nm + n * 20 nm 610 1331 (nm) = 1471 (nm) + n * 20 nm 612 n = (1331-1471)/20 = -7