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Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 2 INTERNET-DRAFT Mohammed Umair 3 Intended Status: Informational Kingston Smiler Selvaraj 4 IPInfusion 5 Donald Eastlake 3rd 6 Lucy Yong 7 Huawei Technologies 8 Expires: April 15, 2017 October 12, 2016 10 TRILL Transparent Transport over MPLS 11 13 Abstract 15 This document specifies how to interconnect multiple Transparent 16 Interconnection of Lots of links (TRILL) sites with an intervening 17 MPLS network using existing TRILL and VPLS standards. This draft 18 addresses two problems as follows: 20 1) Providing connection between more than two TRILL sites that 21 are separated by MPLS provider network. 23 2) Providing a single logical virtualized TRILL network for 24 different tenants that are separated by an MPLS provider network. 26 Status of this Memo 28 This Internet-Draft is submitted to IETF in full conformance with the 29 provisions of BCP 78 and BCP 79. 31 Internet-Drafts are working documents of the Internet Engineering 32 Task Force (IETF), its areas, and its working groups. Note that 33 other groups may also distribute working documents as 34 Internet-Drafts. 36 Internet-Drafts are draft documents valid for a maximum of six months 37 and may be updated, replaced, or obsoleted by other documents at any 38 time. It is inappropriate to use Internet-Drafts as reference 39 material or to cite them other than as "work in progress." 41 The list of current Internet-Drafts can be accessed at 42 http://www.ietf.org/1id-abstracts.html 44 The list of Internet-Draft Shadow Directories can be accessed at 45 http://www.ietf.org/shadow.html 47 Copyright and License Notice 49 Copyright (c) 2016 IETF Trust and the persons identified as the 50 document authors. All rights reserved. 52 This document is subject to BCP 78 and the IETF Trust's Legal 53 Provisions Relating to IETF Documents 54 (http://trustee.ietf.org/license-info) in effect on the date of 55 publication of this document. Please review these documents 56 carefully, as they describe your rights and restrictions with respect 57 to this document. Code Components extracted from this document must 58 include Simplified BSD License text as described in Section 4.e of 59 the Trust Legal Provisions and are provided without warranty as 60 described in the Simplified BSD License. 62 Table of Contents 64 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 4 65 1.1. Terminology . . . . . . . . . . . . . . . . . . . . . . . . 4 66 2. TRILL Over MPLS Model . . . . . . . . . . . . . . . . . . . . . 5 67 3. VPLS Model . . . . . . . . . . . . . . . . . . . . . . . . . . 6 68 3.1. Entities in the VPLS Model . . . . . . . . . . . . . . . . 7 69 3.3. TRILL Adjacency for VPLS model . . . . . . . . . . . . . . 8 70 3.4. MPLS encapsulation for VPLS model . . . . . . . . . . . . . 8 71 3.5. Loop Free provider PSN/MPLS. . . . . . . . . . . . . . . . 8 72 3.6. Frame processing. . . . . . . . . . . . . . . . . . . . . . 8 73 4. VPTS Model . . . . . . . . . . . . . . . . . . . . . . . . . . 8 74 4.1. Entities in the VPTS Model . . . . . . . . . . . . . . . . 10 75 4.1.1. TRILL Intermediate Routers (TIR) . . . . . . . . . . . 11 76 4.1.2. Virtual TRILL Switch/Service Domain (VTSD) . . . . . . 11 77 4.2. TRILL Adjacency for VPTS model . . . . . . . . . . . . . . 11 78 4.3. MPLS encapsulation for VPTS model . . . . . . . . . . . . . 12 79 4.4. Loop Free provider PSN/MPLS. . . . . . . . . . . . . . . . 12 80 4.5. Frame processing. . . . . . . . . . . . . . . . . . . . . . 12 81 4.5.1. Multi-Destination Frame processing . . . . . . . . . . 12 82 4.5.2. Unicast Frame processing . . . . . . . . . . . . . . . 12 83 5. Extensions to TRILL Over Pseudowires [RFC7173] . . . . . . . . 12 84 6. VPTS Model Versus VPLS Model . . . . . . . . . . . . . . . . . 13 85 7. Packet processing between pseudowires . . . . . . . . . . . . . 13 86 8. Security Considerations . . . . . . . . . . . . . . . . . . . . 14 87 9. IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 14 88 10. References . . . . . . . . . . . . . . . . . . . . . . . . . . 14 89 10.1. Normative References . . . . . . . . . . . . . . . . . . . 14 90 10.2. Informative References . . . . . . . . . . . . . . . . . . 15 91 Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . . . 15 92 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 15 94 1. Introduction 96 The IETF Transparent Interconnection of Lots of Links (TRILL) 97 protocol [RFC6325] [RFC7177] [RFC7780] provides transparent 98 forwarding in multi-hop networks with arbitrary topology and link 99 technologies using a header with a hop count and link-state routing. 100 TRILL provides optimal pair-wise forwarding without configuration, 101 safe forwarding even during periods of temporary loops, and support 102 for multipathing of both unicast and multicast traffic. Intermediate 103 Systems (ISs) implementing TRILL are called Routing Bridges(RBridges) 104 or TRILL Switches 106 This draft, in conjunction with [RFC7173] on TRILL Transport using 107 Pseudowires, addresses two problems: 109 1) Providing connection between more than two TRILL sites belongs to 110 a single TRILL network that are separated by an MPLS provider network 111 using [RFC7173]. (Herein also called problem statement 1.) 113 2) Providing a single logical virtualized TRILL network for different 114 tenants that are separated by an MPLS provider network. In short 115 providing connection between TRILL sites belonging to a 116 tenant/tenants over a MPLS provider network. (Herein also called 117 problem statement 2.) 119 A tenant is the administrative entity on whose behalf their 120 associated services are managed. Here tenant refers to a TRILL campus 121 that is segregated from other tenants for security reasons. 123 A key multi-tenancy requirement is traffic isolation so that one 124 tenant's traffic is not visible to any other tenant. This draft also 125 addresses the problem of multi-tenancy by isolating one tenant's 126 traffic from the other. 128 1.1. Terminology 130 Acronyms used in this document include the following: 132 AC - Attachment Circuit [RFC4664] 134 Data Label - VLAN or FGL 136 ECMP - Equal Cost Multi Path 138 FGL - Fine-Grained Labeling [RFC7172] 140 IS-IS - Intermediate System to Intermediate 141 System [IS-IS] 143 LDP - Label Distribution Protocol 145 LAN - Local Area Network 147 MPLS - Multi-Protocol Label Switching 149 PE - Provider Edge Device 151 PSN - Packet Switched Network 153 PW - Pseudowire [RFC4664] 155 TIR - TRILL Intermediate Router 156 (Devices that has both IP/MPLS and TRILL 157 functionality) 159 TRILL - Transparent Interconnection of Lots of 160 Links OR Tunneled Routing in the Link Layer 162 TRILL Site - A part of a TRILL campus that contains at 163 least one RBridge. 165 VLAN - Virtual Local Area Network 167 VPLS - Virtual Private LAN Service 169 VPTS - Virtual Private TRILL Service 171 VSI - Virtual Service Instance [RFC4664] 173 VTSD - Virtual TRILL Switch Domain 174 OR Virtual TRILL Service Domain 175 A Virtual RBridge that segregates one 176 tenant's TRILL database as well as 177 traffic from the other. 179 WAN - Wide Area Network 181 2. TRILL Over MPLS Model 183 TRILL Over MPLS can be achieved by two different ways. 185 a) VPLS Model for TRILL 186 b) VPTS Model/TIR Model 188 Both these models can be used to solve the problem statement 1 and 2. 189 Herein the VPLS Model for TRILL is also called Model 1 and the VPTS 190 Model/TIR Model is also called Model 2. 192 3. VPLS Model 194 Figure 1 shows the topological model of TRILL over MPLS using VPLS 195 model. The PE routers in the below topology model should support all 196 the functional Components mentioned in [RFC4664]. 198 +-----+ +-----+ 199 | RBa +---+ ........................... +---| RBb | 200 +-----+ | . . | +-----+ 201 Site 1 | +----+ +----+ | Site 2 202 +----|PE1 | |PE2 |----+ 203 +----+ MPLS Cloud +----+ 204 . . 205 . +----+ . 206 ..........|PE3 |........... 207 +----+ ^ 208 | | 209 | +-- Emulated LAN 210 +-----+ 211 | RBc | 212 +-----+ 213 Site 3 215 Figure 1: Topological Model of TRILL over MPLS 216 connecting three TRILL Sites 218 Figure 2 below shows the topological model of TRILL over MPLS to 219 connect multiple TRILL sites belonging to a tenant (tenant here is a 220 campus, not a Data label). VSI1 and VSI2 are two Virtual Service 221 Instances that segregate Tenant1's traffic from other tenant traffic. 222 VSI1 will maintain its own database for Tenant1, similarly VSI2 will 223 maintain its own database for Tenant2. 225 +-----+ ............................ +-----+ 226 |RBat1+---+ . ++++++++++++++++++++++++ . +---|RBbt1| 227 +-----+ | . + + . | +-----+ 228 Tenant1 Site 1 | +----+ +----+ | Tenant1 Site2 229 +----|VSI1| |VSI1|----+ 230 +----|VSI2| MPLS Cloud |VSI2|----+ 231 | +----+ +----+ | 232 +-----+ | . + + . | +-----+ 233 |RBat2+---+ . +++++++++ +----+ ++++++++ . +---|RBbt2| 234 +-----+ ............|VSI1|........... +-----+ 235 Tenant2 Site 2 +----|VSI2|----+ ^ Tenant2 Site2 236 | +----+ | | 237 | | | 238 +-----+ +-----+ +-----Emulated 239 |RBct2| |RBct1| LAN 240 +-----+ +-----+ 241 Tenant2 Site 3 Tenant1 Site 3 243 .... VSI1 Path 244 ++++ VSI2 Path 246 Figure 2: Topological Model for VPLS Model 247 connecting 2 Tenants with 3 sites each 249 In this model, TRILL sites are connected to VPLS-capable PE devices that 250 provide a logical interconnect, such that TRILL RBridges belonging to a 251 specific tenant connected via an single bridged Ethernet. These devices 252 are the same as PE devices specified in [RFC4026]. The Attachment 253 Circuit ports of PE Routers are layer 2 switch ports that are connected 254 to the RBridges at a TRILL site. Here each VPLS instance looks like an 255 emulated LAN. This model is similar to connecting different RBridges 256 (TRILL sites) by a layer 2 bridge domain (multi access link) as 257 specified in [RFC6325]. This model doesn't requires any changes in PE 258 routers to carry TRILL packets, as TRILL packets will be transferred 259 transparently. 261 3.1. Entities in the VPLS Model 263 The PE (VPLS-PE) and CE devices are defined in [RFC4026]. 265 The Generic L2VPN Transport Functional Components like Attachment 266 Circuits, Pseudowires, VSI etc. are defined in [RFC4664]. 268 The RB (RBridge) and TRILL Sites are defined in [RFC6325] as updated by 269 [RFC7780]. 271 3.3. TRILL Adjacency for VPLS model 273 As specified in section 3 of this document, the MPLS cloud looks like an 274 emulated LAN (also called multi-access link or broadcast link). This 275 results in RBridges at different sites looking like they are connected 276 by a multi-access link. With such interconnection, the TRILL adjacency 277 over the link are automatically discovered and established through TRILL 278 IS-IS control messages [RFC7177]. These IS-IS control messages are 279 transparently forwarded by the VPLS domain, after doing MPLS 280 encapsulation specified in the section 3.4. 282 3.4. MPLS encapsulation for VPLS model 284 Use of VPLS [RFC4762] to interconnect TRILL sites requires no changes to 285 a VPLS implementation, in particular the use of Ethernet pseudowires 286 between VPLS PEs. A VPLS PE receives normal Ethernet frames from an 287 RBridge (i.e., CE) and is not aware that the CE is an RBridge device. As 288 a result, an MPLS-encapsulated TRILL packet within the MPLS network will 289 use the format illustrated in Appendix A of [RFC7173]. 291 3.5. Loop Free provider PSN/MPLS. 293 No explicit handling is required to avoid loop free topology. Split 294 Horizon technique specified in [RFC4664] will take care of avoiding 295 loops in the provider PSN network. 297 3.6. Frame processing. 299 The PE device transparently process the TRILL control and data frames. 300 Procedures to forward the frames are defined in [RFC4664] 302 4. VPTS Model 304 The (Virtual Private TRILL Service) VPTS is a L2 TRILL service, that 305 emulates TRILL service across a Wide Area Network (WAN). VPTS is similar 306 to what VPLS does for bridge domain. VPLS provides "Virtual Private LAN 307 Service" for different customers. VPTS provides "Virtual Private TRILL 308 Service" for different TRILL tenants. 310 Figure 3 shows the topological model of TRILL over MPLS using VPTS. In 311 this model the PE routers are replaced with TIR (TRILL Intermediate 312 Router) and VSI is replaced with VTSD (Virtual TRILL Switch Domain). The 313 TIR devices must be capable of supporting both MPLS and TRILL and is 314 defined in section 4.1.1. The TIR devices are interconnected via PWs and 315 appear as a unified emulated TRILL campus with each VTSD inside a TIR 316 equivalent to a RBridge. 318 Some of the reasons for interconnecting TRILL Sites without isolating 319 TRILL Control plane of one TRILL site with other is as described below. 321 1) Nickname Uniqueness: One of the basic requirements of TRILL is that, 322 RBridge Nicknames should be unique with in the campus. If we segregate 323 control plane of one TRILL site from other TRILL site and provide 324 interconnection between these sites, it may result in Nickname 325 collision. 327 2) Distribution Tree and its pruning: When a TRILL Data packet traverse 328 a Distribution Tree, it will adhere to it even in other TRILL site. If 329 no end-station service is enabled for a particular Data Label in a TRILL 330 site, Distribution Tree may be pruned and TRILL data packets of that 331 particular Data Label might never get to other TRILL sites. RPF check 332 will always be performed on the packets that are received TIR's through 333 pseudowires. 335 3) Hop Count values: When a TRILL data packet is received over a 336 pseudowire by a TIR, the TIR does the processing of Hop Count defined in 337 [RFC6325] and will not perform any resetting of Hop Count. 339 +-----+ +-----+ 340 | RBa +---+ ........................... +---| RBb | 341 +-----+ | . . | +-----+ 342 Site 1 | +----+ +----+ | Site 2 343 +----|TIR1| |TIR2|----+ 344 +----+ MPLS Cloud +----+ 345 . . 346 . +----+ . 347 ..........|TIR3|........... 348 +----+ ^ 349 | | 350 | +-- Emulated TRILL 351 +-----+ 352 | RBc | 353 +-----+ 354 Site 3 356 Figure 3: Topological Model of VPTS/TIR 357 connecting three TRILL Sites 359 In the above figure (Figure 3) Site1, Site2 and Site3 (running TRILL 360 protocol) are connected to TIR Devices. These TIR devices along with 361 the MPLS cloud looks like an unified emulated TRILL campus. Only the PE 362 devices in the MPLS network should be replaced with TIRs so the 363 intermediate P routers are agnostic to the TRILL protocol. 365 Figure 4 below extends the topological model of TRILL over MPLS to 366 connect multiple TRILL sites belonging to a tenant (tenant here is a 367 campus, not a Data label) using VPTS model. VTSD1 and VTSD2 are two 368 Virtual TRILL Switch Domains (Virtual RBridges) that segregate 369 Tenant1's traffic from Tenant2's traffic. VTSD1 will maintain its own 370 TRILL database for Tenant1, similarly VTSD2 will maintain its own TRILL 371 database for Tenant2. 373 +-----+ ............................ +-----+ 374 |RBat1+---+ . ######################## . +---|RBbt1| 375 +-----+ | . # # . | +-----+ 376 Tenant1 Site 1| +-----+ +-----+ | Tenant1 Site 2 377 +----|VTSD1| |VTSD1|----+ 378 +----|VTSD2| MPLS Cloud |VTSD2|----+ 379 | +-----+ +-----+ | 380 +-----+ | . # # . | +-----+ 381 |RBat2+---+ . #########+-----+######### . +---|RBbt2| 382 +-----+ ...........|VTSD1|........... +-----+ 383 Tenant2 Site2 +---|VTSD2|----+ ^ Tenant2 Site 2 384 | +-----+ | | 385 | | | 386 +-----+ +-----+ +-----Emulated 387 |RBct2| |RBct1| TRILL 388 +-----+ +-----+ 389 Tenant2 Site 3 Tenant1 Site 3 391 .... VTSD1 Connectivity 392 #### VTSD2 Connectivity 394 Figure 4: Topological Model of VPTS/TIR 395 connecting 2 tenants with three TRILL Sites 397 4.1. Entities in the VPTS Model 399 The CE devices are defined in [RFC4026]. 401 The Generic L2VPN Transport Functional Components like Attachment 402 Circuits, Pseudowires etc. are defined in [RFC4664]. 404 The RB (RBridge) and TRILL Campus are defined in [RFC6325] as updated by 405 [RFC7780]. 407 This model introduces two new entities called TIR and VTSD. 409 4.1.1. TRILL Intermediate Routers (TIR) 411 The TIRs [TRILL Intermediate Routers] must be capable of running both 412 VPLS and TRILL protocols. TIR devices are a superset of the VPLS-PE 413 devices defined in [RFC4026] with the additional functionality of TRILL. 414 The VSI instance that provides transparent bridging functionality in the 415 PE device is replaced with VTSD in TIR. 417 4.1.2. Virtual TRILL Switch/Service Domain (VTSD) 419 The VTSD [Virtual Trill Switch Domain] is similar to VSI (layer 2 420 bridge) in VPLS model, but this acts as a TRILL RBridge. The VTSD is a 421 superset of VSI and must support all the functionality provided by the 422 VSI as defined in [RFC4026]. Along with VSI functionality, the VTSD must 423 be capable of supporting TRILL protocols and form TRILL adjacencies. The 424 VTSD must be capable of performing all the operations that a standard 425 TRILL Switch can do. 427 One VTSD instance per tenant must be maintained, when multiple tenants 428 are connected to a TIR. The VTSD must maintain all the information 429 maintained by the RBridge on a per tenant basis. The VTSD must also take 430 care of segregating one tenant traffic from other. Each VTSD should have 431 its own nickname, If a TIR supports 10 TRILL tenants, it needs to be 432 assigned with ten TRILL nicknames and run ten copies of TRILL protocols, 433 one for each. 435 4.2. TRILL Adjacency for VPTS model 437 The VTSD must be capable of forming TRILL adjacency with other VTSDs 438 present in its peer VPTS neighbor, and also the neighbor RBridges 439 present in the TRILL sites. The procedure to form TRILL Adjacency is 440 specified in [RFC7173] and [RFC7177]. 442 4.3. MPLS encapsulation for VPTS model 444 The VPTS model uses PPP pseudowires for MPLS encapsulation as specified 445 in [RFC7173], and requires no changes in the packet format in that RFC. 447 4.4. Loop Free provider PSN/MPLS. 449 This model isn't required to employ Split Horizon mechanism in the 450 provider PSN network, as TRILL takes care of Loop free topology using 451 Distribution Trees. Any multi-destination packet will traverse a 452 distribution tree path. All distribution trees are calculated based on 453 TRILL base protocol standard [RFC6325] as updated by [RFC7780]. 455 4.5. Frame processing. 457 This section specifies multi-destination and unicast frame processing in 458 VPTS/TIR model. 460 4.5.1. Multi-Destination Frame processing 462 Any multi-destination (unknown unicast, multicast or broadcast) packets 463 inside VTSD should be processed or forwarded through any one of the 464 distribution trees. If any multi-destination packet is received from the 465 wrong pseudowire at a VTSD, the TRILL protocol running in VTSD will 466 perform a RPF check as specified in [RFC7780] and drops the packet. 468 Pruning mechanism in Distribution Trees, as specified in [RFC6325] and 469 [RFC7780] can also be used to avoid forwarding of multi-destination data 470 packets on the branches where there are no potential destinations. 472 4.5.2. Unicast Frame processing 474 Unicast packets must be forwarded in same way they get forwarded in a 475 standard TRILL Campus as specified in [RFC6325]. If multiple equal cost 476 paths are available over pseudowires to reach destination, then VTSD 477 should be capable of doing ECMP for them. 479 5. Extensions to TRILL Over Pseudowires [RFC7173] 481 The [RFC7173] mentions how to interconnect a pair of Transparent 482 Interconnection of Lots of Links (TRILL) switch ports using pseudowires. 483 This document explains, how to connect multiple TRILL sites (not limited 484 to only two sites) using the mechanisms and encapsulations defined in 485 [RFC7173]. 487 6. VPTS Model Versus VPLS Model 489 VPLS Model uses a simpler loop breaking rule: the "split horizon" rule, 490 where a PE must not forward traffic from one PW to another in the same 491 VPLS mesh. 493 An issue with the above rule is that if a pseudowire between PEs fails, 494 frames will not get forwarded between the PEs where pseudowire went 495 down. 497 VPTS solves this problem, as the VPTS Model uses distribution Trees for 498 loop free topology. Hence the frames reach all TIRs even when any one of 499 the pseudowires fails in the mesh. 501 If equal cost paths are available to reach a site over pseudowires, VPTS 502 Model can use ECMP for processing of frames over pseudowires. 504 7. Packet processing between pseudowires 506 Whenever a packet gets received over a pseudowire, VTSD will decapsulate 507 the MPLS headers followed by checking the TRILL header. If the egress 508 nickname in the TRILL header is for a TRILL site located beyond another 509 pseudowire, then VTSD will encapsulate with new MPLS headers and send it 510 across the proper pseudowire. 512 For example in figure 3, consider that the pseudowire between TIR1 and 513 TIR2 fails, Then TIR1 will communicate with TIR2 via TIR3, whenever 514 packets which are destined to TIR3 gets received from pseudowire between 515 TIR1 and TIR3, VTSD inside TIR3 will decapsulate the MPLS headers, then 516 check the TRILL header's egress nickname field. If egress nickname is 517 destained for the RBridge in site3 then the packet will be sent to RBc, 518 if egress nickname is located at site2, VTSD will add MPLS headers for 519 the pseudowire between TIR3 and TIR2 and forward the packet on that 520 pseudowire. 522 8. Security Considerations 524 For general TRILL security considerations, see [RFC6325] 526 For transport of TRILL by Pseudowires security consideration, see 527 [RFC7173]. 529 For general VPLS security considerations, see [RFC4762] 531 Since the VPTS Model uses Distribution trees for processing of multi- 532 destination data packets, it is always advisable to have at least one 533 Distribution tree root to be located in every TRILL site. This will 534 avoid data packets getting received at TRILL sites where end-station 535 service is not enabled for that data packet. 537 9. IANA Considerations 539 This document requires no IANA actions. RFC Editor: Please delete this 540 section before publication 542 10. References 544 10.1. Normative References 546 [IS-IS] "Intermediate system to Intermediate system routeing 547 information exchange protocol for use in conjunction with 548 the Protocol for providing the Connectionless-mode Network 549 Service (ISO 8473)", ISO/IEC 10589:2002, 2002". 551 [RFC6325] Perlman, R., Eastlake 3rd, D., Dutt, D., Gai, S., and A. 552 Ghanwani, "Routing Bridges (RBridges): Base Protocol 553 Specification", RFC 6325, DOI 10.17487/RFC6325, July 2011, 554 . 556 [RFC4762] Lasserre, M., Ed., and V. Kompella, Ed., "Virtual Private 557 LAN Service (VPLS) Using Label Distribution Protocol (LDP) 558 Signaling", RFC 4762, DOI 10.17487/RFC4762, January 2007, 559 . 561 [RFC7173] Yong, L., Eastlake 3rd, D., Aldrin, S., and J. Hudson, 562 "Transparent Interconnection of Lots of Links (TRILL) 563 Transport Using Pseudowires", RFC 7173, DOI 564 10.17487/RFC7173, May 2014, . 567 [RFC7177] Eastlake 3rd, D., Perlman, R., Ghanwani, A., Yang, H., and 568 V. Manral, "Transparent Interconnection of Lots of Links 569 (TRILL): Adjacency", RFC 7177, DOI 10.17487/RFC7177, May 570 2014, . 572 [RFC7780] Eastlake 3rd, D., Zhang, M., Perlman, R., Banerjee, A., 573 Ghanwani, A., and S. Gupta, "Transparent Interconnection 574 of Lots of Links (TRILL): Clarifications, Corrections, and 575 Updates", RFC 7780, DOI 10.17487/RFC7780, February 2016, 576 . 578 10.2. Informative References 580 [RFC4026] Andersson, L. and T. Madsen, "Provider Provisioned Virtual 581 Private Network (VPN) Terminology", RFC 4026, DOI 582 10.17487/RFC4026, March 2005, . 585 [RFC4664] Andersson, L., Ed., and E. Rosen, Ed., "Framework for 586 Layer 2 Virtual Private Networks (L2VPNs)", RFC 4664, DOI 587 10.17487/RFC4664, September 2006, . 590 [RFC7172] Eastlake 3rd, D., Zhang, M., Agarwal, P., Perlman, R., and 591 D. Dutt, "Transparent Interconnection of Lots of Links 592 (TRILL): Fine-Grained Labeling", RFC 7172, DOI 593 10.17487/RFC7172, May 2014, . 596 Acknowledgements 598 The contributions of Andrew G. Malis is gratefully acknowledged in 599 improving the quality of this document. 601 Authors' Addresses 602 Mohammed Umair 603 IPInfusion 604 RMZ Centennial 605 Mahadevapura Post 606 Bangalore - 560048 India 608 EMail: mohammed.umair2@gmail.com 610 Kingston Smiler Selvaraj 611 IPInfusion 612 RMZ Centennial 613 Mahadevapura Post 614 Bangalore - 560048 India 616 EMail: kingstonsmiler@gmail.com 618 Donald E. Eastlake 3rd 619 Huawei Technologies 620 155 Beaver Street 621 Milford, MA 01757 622 USA 624 Phone: +1-508-333-2270 625 EMail: d3e3e3@gmail.com 627 Lucy Yong 628 Huawei Technologies 629 5340 Legacy Drive 630 Plano, TX 75024 631 USA 633 Phone: +1-469-227-5837 634 EMail: lucy.yong@huawei.com