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Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 1 Network Working Group Iftekhar Hussain 2 Internet Draft Abinder Dhillon 3 Intended status: Standard Track Zhong Pan 4 Expires: March 2013 Marco Sosa 5 Infinera 7 Bert Basch 8 Steve Liu 9 Andrew G. Malis 10 Verizon Communications 12 September 5, 2012 14 Generalized Label for Super-Channel Assignment on Flexible Grid 15 draft-hussain-ccamp-super-channel-label-04.txt 17 Abstract 19 To enable scaling of existing transport systems to ultra high data 20 rates of 1 Tbps and beyond, next generation systems providing super- 21 channel switching capability are currently being developed. To allow 22 efficient allocation of optical spectral bandwidth for such high bit 23 rate systems, International Telecommunication Union 24 Telecommunication Standardization Sector (ITU-T) is extending the 25 G.694.1 grid standard (termed "Fixed-Grid") to include flexible grid 26 (termed "Flex-Grid") support (draft revised ITU-T G.694.1, revision 27 1.4, Oct 2011). This necessitates definition of new label format for 28 the Flex-Grid. This document defines a super-channel label as a 29 Super-Channel Identifier and an associated list of 12.5 GHz slices 30 representing the optical spectrum of the super-channel. The label 31 information can be encoded using a fixed length or variable length 32 format. This label format can be used in GMPLS signaling and routing 33 protocol to establish super-channel based optical label switched 34 paths (LSPs). 36 Status of this Memo 38 This Internet-Draft is submitted in full conformance with the 39 provisions of BCP 78 and BCP 79. 41 Internet-Drafts are working documents of the Internet Engineering 42 Task Force (IETF), its areas, and its working groups. Note that 43 other groups may also distribute working documents as Internet- 44 Drafts. 46 Internet-Drafts are draft documents valid for a maximum of six 47 months and may be updated, replaced, or obsoleted by other documents 48 at any time. It is inappropriate to use Internet-Drafts as 49 reference material or to cite them other than as "work in progress." 51 The list of current Internet-Drafts can be accessed at 52 http://www.ietf.org/ietf/1id-abstracts.txt 54 The list of Internet-Draft Shadow Directories can be accessed at 55 http://www.ietf.org/shadow.html 57 This Internet-Draft will expire on March 5, 2013. 59 Copyright Notice 61 Copyright (c) 2012 IETF Trust and the persons identified as the 62 document authors. All rights reserved. 64 This document is subject to BCP 78 and the IETF Trust's Legal 65 Provisions Relating to IETF Documents 66 (http://trustee.ietf.org/license-info) in effect on the date of 67 publication of this document. Please review these documents 68 carefully, as they describe your rights and restrictions with 69 respect to this document. Code Components extracted from this 70 document must include Simplified BSD License text as described in 71 Section 4.e of the Trust Legal Provisions and are provided without 72 warranty as described in the Simplified BSD License. 74 Table of Contents 76 1. Introduction...................................................3 77 2. Terminology....................................................6 78 3. Motivation for Super-Channel Label.............................6 79 3.1. Flex-Grid Slice Numbering.................................6 80 3.2. Super-Channel Label.......................................7 81 3.2.1. Super-Channel Label Encoding Format..................8 82 3.2.2. LSP Encoding Type, Switching Type, and Generalized-PID 83 (G-PID) in Generalized Label Request.......................11 84 4. Security Considerations.......................................11 85 5. IANA Considerations...........................................11 86 6. References....................................................11 87 6.1. Normative References.....................................11 88 6.2. Informative References...................................12 89 7. Acknowledgments...............................................12 90 Appendix A. Super-Channel Label Format Example...................13 92 1. Introduction 94 Future transport systems are expected to support service upgrades to 95 data rates of 1 Tbps and beyond. To scale networks beyond 100Gbps, 96 multi-carrier super-channels coupled with advanced multi-level 97 modulation formats and flexible channel spectrum bandwidth 98 allocation schemes have become pivotal for future spectral efficient 99 transport network architectures [1,2]. 101 A super-channel represents an ultra high aggregate capacity channel 102 containing multiple carriers which are co-routed through the network 103 as a single entity from the source transceiver to the sink 104 transceiver [3,7]. By multiplexing multiple carriers, modulating 105 each carrier with multi-level advanced modulation formats (such as 106 PM-QPSK, PM-8QAM, PM-16QAM), allocating an appropriate-sized 107 flexible channel spectral bandwidth slot, and using a coherent 108 receiver for detecting closely packed sub-carriers, a super-channel 109 can support ultra high data rates in a spectrally efficient manner 110 while maintaining required system reach. Figure 1 contrasts channel 111 spectrum bandwidth allocation schemes for various bit rate optical 112 paths on fixed-grid and flex-grid. ITU-T fixed-grid permits 113 allocation of channel spectrum bandwidth in "single" fixed-sized 114 slots (e.g., 50GHz, 100GHz etc) independent of the channel bit rate. 115 In contrast, a flex-grid can allocate "arbitrary" size channel 116 spectral bandwidth as an integer multiple of 12.5 GHz fine 117 granularity slices. This means, a flex-grid can support multiple 118 data rates channels (optical paths) in a spectrally efficient manner 119 as it allocates appropriate-sized spectrum bandwidth slots, as 120 opposed to fixed-sized slots. As in the examples in the figure, the 121 optical spectrum slices assigned will be to a given super-channel in 122 a contiguous manner. However, for flexibility in finding available 123 optical spectrum on fragmented fibers and to reduce signaling 124 message overhead, the two schemes proposed in this document also 125 allow for identification of a split-spectrum super-channel with 126 optical spectral slices that are non-contiguous, spread across 127 multiple slots. Note that the channel capacity available on a given 128 number of optical spectral slices depends on (among other factors) 129 how many contiguous optical slots are used. The definition of the 130 channel capacity available for a split-spectrum super-channel split 131 across multiple slots of different widths is outside the scope of 132 this document. 134 ITU-T G.694.1 135 Center frequency (f) = 193.1 THz 137 n=-3 n=-2 n=-1 n=0 n=+1 n=+2 139 ^ ^ ^ ^ ^ ^ 140 ... | | | | | | ... 141 || | | | | | | | | | 142 +--------+-------+-------+-------+-------+--- 143 <-- --> <-- --> 144 50 GHz 50 GHz 146 ^ ^ 147 | n=-2 | n= +1 148 | | 149 +------+ +------+ 150 |50 GHz| |50 GHz| 151 +------+ +------+ 153 (10 Gbps channel) (40Gbps channel) 154 (a fixed 50GHz chunk) (a fixed 50GHz chunk) 156 (a) 158 ^ ^ ^ ^ ^ ^ 159 | | | | | ++| 160 ... |-|-|-|-|-|-|-|-| |+|+|+|+|+|+|+|+|+|1|1| ... 161 |8|7|6|5|4|3|2|1|0|1|2|3|4|5|6|7|8|9|0|1| 162 ---+-------+-------+-------+-------+-------+--- 164 ^ ^ ^ 165 |<-- 200 GHz -->|<- ->| 166 | | 50GHz | 167 +-------------------------------+-------+ 168 | 1 Tbps super-channel |100Gbps| 169 | 16 slices of 12.5 GHz |Channel| 170 | |4slices| 171 +-------------------------------+-------+ 173 (b) 175 Figure 1 ITU-T (a) 50 GHz fixed-grid (G.694.1) (b) 12.5 GHz granular 176 flex-grid 178 2. Terminology 180 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL 181 NOT","SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in 182 this document are to be interpreted as described in RFC 2119 183 [RFC2119]. 185 3. Motivation for Super-Channel Label 187 [RFC3471] defines new forms of MPLS "label" for the optical domain 188 that are collectively referred to as a "generalized label". 189 [RFC6205] defines a standard wavelength label based on ITU-T fixed- 190 grids ([G.694.1] and [G.694.2]) for use by Lambda-Switch-Capable 191 (LSC) LSRs. 193 A new label format for super-channels assignment on flex-grid is 194 needed because the existing label formats (such as the waveband 195 switching label defined in RFC3471 and the wavelength label defined 196 in RFC6205) either lack necessary fields to carry required flex-grid 197 related information (e.g., channel spacing) or do not allow 198 signaling of arbitrary flexible-size optical spectral bandwidth in 199 an efficient manner (e.g., in terms of integer multiple of fine 200 granularity 12.5GHz slices). For example, 202 o Waveband switching label format (defined in section 3.3.1 of 203 RFC3471) lacks fields to carry necessary information to support 204 flex-grid. 206 o Wavelength label allows signaling of single fixed-size optical 207 spectrum bandwidth slot only. 209 o Wavelength label does not allow signaling of arbitrary flexible- 210 size optical spectrum bandwidth needed for super-channels 211 assignment on flex-grid. 213 3.1. Flex-Grid Slice Numbering 215 Given a slice spacing value (e.g., 0.0125 THz) and a slice number 216 "n", the slice left edge frequency can be calculated as follows: 218 Slice Left Edge Frequency(THz)= 193.1 THz + n*slice spacing (THz). 220 Where "n" is a two's-complement integer (i.e., positive, negative, 221 or 0) and "slice spacing" is 0.0125 THz conforming to ITU-T Flex- 222 Grid.(Editor's Note: in the future, if necessary the slice numbering 223 scheme will be updated in accordance with the Flex-Grid.) 225 Figure 2 shows an example using the slice number scheme described 226 earlier. 228 3.2. Super-Channel Label 230 In order to setup an optical path manually or dynamically, we need a 231 way to identify and reserve resources (i.e., signal optical spectral 232 bandwidth for the super-channels) along the optical path. For this 233 purpose, this document defines a super-channel label to cover the 234 cases of split-spectrum super-channels as well, such that the label 235 consists of a Super-Channel Identifier and an associated list of 236 contiguous or non-contiguous set of 12.5 GHz slices representing 237 arbitrary size optical spectrum of the super-channels (Note: in the 238 future, slice granularity could be 6.25 GHz.) 240 (n=0 is 193.1 THz) 242 n=-2 n=-1 n=0 n=+1 n=+2 244 ^ ^ ^ ^ ^ 245 | | | | | 246 ... |-|-|-|-|-|-|-|-| |+|+|+|+|+|+|+| ... 247 |8|7|6|5|4|3|2|1|0|1|2|3|4|5|6|7| 248 ---+-------+-------+-------+-------+--- 249 ^ ^ 250 | | 251 | | 252 +-----------------------+ 253 | A super-channel with | 254 | Spectral BW = 150 GHz | 255 |(12 slices of 12.5 GHz)| 256 | | 257 | n_start= -7 | 258 | n_end = +4 | 259 | | 260 | (see label encoding | 261 | format for details) | 262 +-----------------------+ 264 Figure 2 flex-grid example of the proposed slice numbering scheme. 266 3.2.1. Super-Channel Label Encoding Format 268 This section describes two options (option A and B) for encoding the 269 super-channel label by making extensions to the waveband switching 270 label[RFC3471] and wavelength label[RFC6205] formats. 272 o Option A: Encode super-channel label as a list of start and end 273 slice numbers corresponding to N slots, each consisting of 274 contiguous slices with each slot denoted by its starting and 275 ending slice number (e.g., "n_start_1" and "n_end_1" represent 276 contiguous slices in slot#1, "n_start 2" and "n_end 2" in slot#2, 277 ..., "n_start N" and "n_end N" in slot#N). 279 0 1 2 3 280 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 1 281 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 282 | Super-Channel Id(16-bit) |Grid | S.S. | Reserved (9-bit)| 283 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 284 | Reserved (16-bit) | Number of Entries(16-bit) | 285 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 286 |n_start_1(contiguous slot #1) | n_end_1(contiguous slot #1) | 287 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 288 |n_start_2(contiguous slot#2) | n_end_2(contiguous slot#2) | 289 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 290 | | 291 | ... | 292 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 293 |n_start_N (contiguous slot#N) | n_end_N (contiguous slot #N | 294 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 296 Super-Channel Id: 16 bits 298 This field represents a logical identifier for a super-channel or 299 split-spectrum super-channel. To disambiguate waveband switching 300 and super-channel label applications, we propose to rename the 301 Waveband Identifier (32-bit) as a Super-Channel Identifier (16- 302 bit). 304 Grid: 3 bits 306 This field indicates the Grid type. The value for Grid should be 307 set to xx (to be assigned by IANA) for the ITU-T flex-grid. 309 +----------------+---------+ 310 | Grid | Value | 311 +----------------+---------+ 312 | Reserved | 0 | 313 +----------------+---------+ 314 |ITU-T DWDM | 1 | 315 +----------------+---------+ 316 |ITU-T CWDM | 2 | 317 +----------------+---------+ 318 |ITU-T Flex-Grid | xx (TBD)| 319 +----------------+---------+ 320 |Future use | 3 - 7 | 321 +----------------+---------+ 323 S.S. (slice spacing): 4 bits 325 This field should be set to a value of 4 to indicate 12.5 GHz in 326 both labels. 328 +----------+---------+ 329 |S.S. (GHz)| Value | 330 +----------+---------+ 331 | Reserved | 0 | 332 +----------+---------+ 333 | 100 | 1 | 334 +----------+---------+ 335 | 50 | 2 | 336 +----------+---------+ 337 | 25 | 3 | 338 +----------+---------+ 339 | 12.5 | 4 | 340 +----------+---------+ 341 |Future use| 5 - 15 | 342 +----------+---------+ 344 Number of Entries: 16-bit 346 This field represents the number of 32-bit entries in the 347 super-channel label (i.e., number of slots with contiguous 348 slices). For example, in the case of a super-channel with 349 contiguous optical spectrum, this field should have a value of 1 350 (indicating one slot of contiguous slices). 352 n_start_i (i=1,2,...N): 16 bits 354 n_end_i (i=1,2,...N): 16 bits 356 A super-channel with contiguous spectrum or a split-spectrum super- 357 channel with non-contiguous optical spectrum can be represented by N 358 slots of slices where two adjacent slots can be contiguous or non- 359 contiguous, however each slot contains contiguous slices. Each slot 360 is denoted by n_start_i (which indicates the lowest or starting 12.5 361 GHz slice number of the slot) and n_end_i (which indicates the 362 highest or ending 12.5 GHz slice number of the slot). "n_start_i" 363 and "n_end_i" are two's-complement integers that can take either a 364 positive, negative, or zero value. 366 o Option B: Encode super-channel label as a first slice number of 367 the grid (denoted as "n_start of Grid") plus the entire list of 368 slices in the grid as a Bitmap 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 | Super-Channel Id (16-bit) |Grid | S.S. | Reserved (9-bit)| 374 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 375 |n_start of Grid (16-bit) |Num of Slices in Grid (16-bit) | 376 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 377 |Bitmap Word #1(first set of 32 slices from the left most edge) | 378 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 379 |Bitmap Word #2 (next set of 32 contiguous slice numbers) | 380 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 381 | | 382 ... 383 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 384 |Bitmap Word #N(last set of 32 contiguous slice numbers) | 385 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 387 Where: 389 Super-Channel Id, Grid, and S.S fields are same as described 390 earlier in option A. 392 n_start of Grid: 16-bit 394 This field indicates the first slice number in Grid for the 395 band being referenced (i.e., the start of the left most edge of 396 the Grid). 398 Numof Slices in Grid: 16-bit 400 This field represents the total number of slices in the band. 401 The value in this field determines the number of 32-bitmap words 402 required for the grid. 404 Bit map (Word): 32-bit 405 Each bit in the 32-bitmap word represents a particular slice 406 with a value of 1 or 0 to indicate whether for that slice 407 reservation is required (1) or not (0). Bit position zero in 408 the first word represents the first slice in the band (Grid) 409 and corresponds to the value indicated in the "n_start of 410 Grid" field. 412 Both options allow efficient encoding of a super-channel label with 413 contiguous and non-contiguous slices. Option B yields a fixed length 414 format while option A a variable length format. Option B is 415 relatively simpler, more flexible, however, might be less compact 416 than option A for encoding a single super-channel with contiguous 417 optical spectrum. In contrast, option A provides a very compact 418 representation for super-channels with contiguous optical spectrum, 419 however, might be less flexible in encoding split-spectrum super- 420 channels with arbitrary non-contiguous set of slices. 422 3.2.2. LSP Encoding Type, Switching Type, and Generalized-PID (G-PID) 423 in Generalized Label Request 425 For requesting a super-channel label in a Generalized Label Request 426 defined in section 3.1.1 of RFC3471, this document proposes to use 427 LSP Encoding Type = Lambda (as defined in RFC4328), Switching Type = 428 Super-Channel-Switch-Capable(SCSC) (as defined in [6]), and a new G- 429 PID type = OTUadaptand a new G-PID value (similar to as defined in 430 section 3.1.3 of RFC4328) to be assigned by IANA. 432 4. Security Considerations 434 436 5. IANA Considerations 438 IANA needs to assign a new Grid field value to represent ITU-T Flex- 439 Grid and a new G-PID value. 441 6. References 443 6.1. Normative References 445 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 446 Requirement Levels", BCP 14, RFC 2119, March 1997. 448 [RFC3471] Berger, L., Ed., "Generalized Multi-Protocol Label 449 Switching (GMPLS) Signaling Functional Description", RFC 450 3471, January 2003. 452 [RFC6205] Otani, T., Ed., "Generalized Labels for Lambda-Switch- 453 Capable (LSC) Label Switching Routers", RFC 6205, March 454 2011. 456 [RFC6163] Lee, Y., Ed., "Framework for GMPLS and Path Computation 457 Element (PCE) Control of Wavelength Switched Optical 458 Networks (WSONs)", RFC 6163, April 2011 460 6.2. Informative References 462 [1] Gringeri, S., Basch, B. Shukla,V. Egorov, R. and Tiejun J. 463 Xia, "Flexible Architectures for Optical Transport Nodes and 464 Networks", IEEE Communications Magazine, July 2010, pp. 40-50 466 [2] M. Jinnoet. al., "Spectrum-Efficient and Scalable Elastic 467 Optical Path Network: Architecture, Benefits and Enabling 468 Technologies", IEEE Comm. Mag., Nov. 2009, pp. 66-73. 470 [3] S. Chandrasekhar and X. Liu, "Terabit Super-Channels for High 471 Spectral Efficiency Transmission",in Proc. ECOC 2010, paper 472 Tu.3.C.5, Torino (Italy), September 2010. 474 [4] ITU-T Recommendation G.694.1, "Spectral grids for WDM 475 applications: DWDM frequency grid", June 2002 477 [5] [4] "Finisar to Demonstrate Flexgrid(TM) WSS Technology at 478 ECOC 2010", press release. 480 [6] Abinder D., et. al., "OSPFTE extension to support GMPLS for 481 Flex Grid", draft-dhillon-ccamp-super-channel-ospfte-ext, work 482 in progress, October 2011. 484 [7] Sharfuddin S., et. al., "A Framework for control of Flex Grid 485 Networks", draft-syed-ccamp-flexgrid-framework-ext, work in 486 progress, March 2012. 488 7. Acknowledgments 490 492 Appendix A. Super-Channel Label Format Example 494 Suppose node A and Node Z are super-channel switching capable and 495 node A receives a request for establishing a 1 Tbps optical LSP from 496 itself to node Z. Assume the super-channel requires a "contiguous" 497 spectral bandwidth of 200 GHz with left-edge frequency of 191.475 498 THz for the left-most 12.5 GHz slice and left-edge frequency of 499 191.6625 THz for the right-most slice. This means n_start = (191.475 500 - 193.1)/0.0125 = -130 and n_end = (191.6625 - 193.1)/0.0125 = -115 501 (i.e. we need 16 slices of 12.5 GHz starting from slice number -130 502 and ending at slice number -115). 504 Node A signals the LSP via a Path message including a super-channel 505 label format encoding option A defined in section 3.3: 507 0 1 2 3 508 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 1 509 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 510 | Super-Channel Id (16-bit) |Grid | S.S. | Reserved (9-bit)| 511 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 512 | Reserved (16-bit) | Number of Entries (16-bit) | 513 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 514 |n_start_1 (contiguous slot #1) | n_end_1(contiguous slot#1) | 515 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 516 Where: 518 Super-Channel Id = 1 :super-channel number 1 520 Number of Entries: 1 522 Grid = xx : ITU-T Flex-Grid 524 S.S. = 4 : 12.5 GHz Slice Spacing 526 n_start_1 = -130 : left-most 12.5 GHz slice number for slot 1 528 n_end_1= -115 : Right-most 12.5 GHz slice number for slot 1 530 Authors' Addresses 532 Iftekhar Hussain 533 Infinera 534 140 Caspian Ct., Sunnyvale, CA 94089 536 Email: ihussain@infinera.com 538 Abinder Dhillon 539 Infinera 540 140 Caspian Ct., Sunnyvale, CA 94089 542 Email: adhillon@infinera.com 544 Zhong Pan 545 Infinera 546 140 Caspian Ct., Sunnyvale, CA 94089 548 Email: zpan@infinera.com 550 Marco Sosa 551 Infinera 552 140 Caspian Ct., Sunnyvale, CA 94089 554 Email: msosa@infinera.com 556 BertBasch 557 Verizon Communications 558 60Sylvan Rd., Waltham, MA02451 560 Email: bert.e.basch@verizon.com 562 SteveLiu 563 Verizon Communications 564 60Sylvan Rd., Waltham, MA02451 566 Email: steve.liu@verizon.com 567 Andrew G. Malis 568 Verizon Communications 569 60Sylvan Rd., Waltham, MA02451 571 Email: andrew.g.malis@verizon.com 573 Contributor's Addresses 575 Rajan Rao 576 Infinera 577 140 Caspian Ct., Sunnyvale, CA 94089 579 Email: rrao@infinera.com 581 Biao Lu 582 Infinera 583 140 Caspian Ct., Sunnyvale, CA 94089 585 Email: blu@infinera.com 587 Subhendu Chattopadhyay 588 Infinera 589 140 Caspian Ct., Sunnyvale, CA 94089 591 Email: schattopadhyay@infinera.com 593 Harpreet Uppal 594 Infinera 595 140 Caspian Ct., Sunnyvale, CA 94089 597 Email: harpreet.uppal@infinera.com