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Miscellaneous warnings: ---------------------------------------------------------------------------- == The copyright year in the IETF Trust and authors Copyright Line does not match the current year == Using lowercase 'not' together with uppercase 'MUST', 'SHALL', 'SHOULD', or 'RECOMMENDED' is not an accepted usage according to RFC 2119. Please use uppercase 'NOT' together with RFC 2119 keywords (if that is what you mean). Found 'MUST not' in this paragraph: While it MUST NOT happen, and is seen as invallid combination, it is possible from a semenatics perspective to have multiple clashing redirect actions defined within a single flowspec rule. For best and consistant RFC5575 flowspec redirect behavior the redirect as documented by RFC5575 MUST not be broken, and hence when a clash occurs, then RFC5575 based redirect SHOULD take priority. Additionally, if the 'redirect to indirection-id' does not result in a valid redirection, then the flowspec rule must be processed as if the 'redirect to indirection-id' community was not attached to the flowspec route and MUST provide an indication within the BGP routing table that the respective 'redirect to indirection-id' resulted in an invalid redirection action. -- The document date (August 30, 2016) is 2794 days in the past. Is this intentional? Checking references for intended status: Proposed Standard ---------------------------------------------------------------------------- (See RFCs 3967 and 4897 for information about using normative references to lower-maturity documents in RFCs) -- Looks like a reference, but probably isn't: 'I-D.draft-ietf-spring-segment-routing' on line 370 -- Looks like a reference, but probably isn't: 'RFC-To-Be' on line 518 ** Obsolete normative reference: RFC 5575 (ref. '2') (Obsoleted by RFC 8955) Summary: 2 errors (**), 0 flaws (~~), 2 warnings (==), 3 comments (--). Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 2 IDR Working Group G. Van de Velde, Ed. 3 Internet-Draft Nokia 4 Intended status: Standards Track K. Patel 5 Expires: March 3, 2017 Cisco Systems 6 Z. Li 7 Huawei Technologies 8 August 30, 2016 10 Flowspec Indirection-id Redirect 11 draft-ietf-idr-flowspec-path-redirect-00 13 Abstract 15 Flowspec is an extension to BGP that allows for the dissemination of 16 traffic flow specification rules. This has many possible 17 applications but the primary one for many network operators is the 18 distribution of traffic filtering actions for DDoS mitigation. The 19 flow-spec standard RFC5575 [2] defines a redirect-to-VRF action for 20 policy-based forwarding but this mechanism is not always sufficient, 21 particularly if the redirected traffic needs to be steered into an 22 engineered path or into a service plane. 24 This document defines a new extended community known as redirect-to- 25 indirection-id (32-bit) flowspec action to provide advanced 26 redirection capabilities on flowspec clients. When activated, the 27 flowspec extended community is used by a flowspec client to find the 28 correct next-hop entry within a localised indirection-id mapping 29 table. 31 The functionality present in this draft allows a network controller 32 to decouple flowspec functionality from the creation and maintainance 33 of the network's service plane itself including the setup of tunnels 34 and other service constructs that could be managed by other network 35 devices. 37 Requirements Language 39 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 40 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this 41 document are to be interpreted as described in RFC 2119 [1]. 43 Status of This Memo 45 This Internet-Draft is submitted in full conformance with the 46 provisions of BCP 78 and BCP 79. 48 Internet-Drafts are working documents of the Internet Engineering 49 Task Force (IETF). Note that other groups may also distribute 50 working documents as Internet-Drafts. The list of current Internet- 51 Drafts is at http://datatracker.ietf.org/drafts/current/. 53 Internet-Drafts are draft documents valid for a maximum of six months 54 and may be updated, replaced, or obsoleted by other documents at any 55 time. It is inappropriate to use Internet-Drafts as reference 56 material or to cite them other than as "work in progress." 58 This Internet-Draft will expire on March 3, 2017. 60 Copyright Notice 62 Copyright (c) 2016 IETF Trust and the persons identified as the 63 document authors. All rights reserved. 65 This document is subject to BCP 78 and the IETF Trust's Legal 66 Provisions Relating to IETF Documents 67 (http://trustee.ietf.org/license-info) in effect on the date of 68 publication of this document. Please review these documents 69 carefully, as they describe your rights and restrictions with respect 70 to this document. Code Components extracted from this document must 71 include Simplified BSD License text as described in Section 4.e of 72 the Trust Legal Provisions and are provided without warranty as 73 described in the Simplified BSD License. 75 Table of Contents 77 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3 78 2. indirection-id and indirection-id table . . . . . . . . . . . 3 79 3. Use Case Scenarios . . . . . . . . . . . . . . . . . . . . . 4 80 3.1. Redirection shortest Path tunnel . . . . . . . . . . . . 4 81 3.2. Redirection to path-engineered tunnels . . . . . . . . . 5 82 3.3. Redirection to Next-next-hop tunnels . . . . . . . . . . 6 83 4. Redirect to indirection-id Community . . . . . . . . . . . . 7 84 5. Redirect using localised indirection-id mapping table . . . . 9 85 6. Validation Procedures . . . . . . . . . . . . . . . . . . . . 9 86 7. Security Considerations . . . . . . . . . . . . . . . . . . . 10 87 8. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 10 88 9. Contributor Addresses . . . . . . . . . . . . . . . . . . . . 10 89 10. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 11 90 11. References . . . . . . . . . . . . . . . . . . . . . . . . . 12 91 11.1. Normative References . . . . . . . . . . . . . . . . . . 12 92 11.2. Informative References . . . . . . . . . . . . . . . . . 13 93 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 13 95 1. Introduction 97 Flowspec RFC5575 [2] is an extension to BGP that allows for the 98 dissemination of traffic flow specification rules. This has many 99 possible applications, however the primary one for many network 100 operators is the distribution of traffic filtering actions for DDoS 101 mitigation. 103 Every flowspec policy route is effectively a rule, consisting of a 104 matching part (encoded in the NLRI field) and an action part (encoded 105 in one or more BGP extended communities). The flow-spec standard 106 RFC5575 [2] defines widely-used filter actions such as discard and 107 rate limit; it also defines a redirect-to-VRF action for policy-based 108 forwarding. Using the redirect-to-VRF action to steer traffic 109 towards an alternate destination is useful for DDoS mitigation but 110 using this technology can be cumbersome when there is need to steer 111 the traffic onto an engineered traffic path. 113 This draft proposes a new redirect-to-indirection-id flowspec action 114 facilitating an anchor point for policy-based forwarding onto an 115 engineered path or into a service plane. The flowspec client 116 consuming and utilizing the new flowspec indirection-id extended- 117 community finds the redirection information within a localised 118 indirection-id mapping table. The localised mapping table is a table 119 construct providing at one side the table key and at the other side 120 next-hop information. The table key consists out the combination of 121 indirection-id type and indirection-id 32-bit value. 123 The redirect-to-indirection-id flowspec action is encoded in a newly 124 defined BGP extended community. In addition, the type of redirection 125 can be configured as an extended community indirection-id type field. 127 This draft defines the indirection-id extended-community and the 128 wellknown indirection-id types. The specific solution to construct 129 the localised indirection-id mapping table are out-of-scope of this 130 document. 132 2. indirection-id and indirection-id table 134 An indirection-id is an abstract number (32-bit value) used as 135 identifier for a localised indirection decision. The indirection-id 136 will allow a flowspec client to redirect traffic into a service plane 137 or onto an engineered traffic path. For example, when a BGP flowspec 138 controller signals a flowspec client the indirection-id extended 139 community, then the flowspec client uses the indirection-id to make a 140 recursive lookup to retrieve next-hop information found in a 141 localised indirection mapping table. 143 The indirection-id table is a router localised table. The 144 indirection-id table is constructed out of table keys mapped to 145 flowspec client localised redirection information. The table key is 146 created by the combination of the indirection-id type and the 147 indirection-id 32-bit value. Each entry in the indirection-table key 148 maps to sufficient information (parameters regarding encapsulation, 149 interface, QoS, etc...) to successfully redirect traffic. 151 3. Use Case Scenarios 153 This section describes use-case scenarios when deploying redirect-to- 154 indirection-id. 156 3.1. Redirection shortest Path tunnel 158 Possible Indirection-ID type examples: 160 o When deploying on flowspec client a localised Indirection-id 161 table: 0 (localised ID) 163 o When deploying on flowspec client a Segment Routing based 164 Indirection-id table: 1 (Node ID) 166 Description: 168 A first use-case is allowing a BGP Flowspec controller to send a 169 single flowspec policy route (i.e. flowspec_route#1) to many BGP 170 flowspec clients. This flowspec route signals the Flowspec clients 171 to redirect traffic onto a tunnel towards a single IP destination 172 address. 174 For this first use-case scenario, the flowspec client receives from 175 the flowspec controller a flowspec route (i.e. flowspec_route#1) 176 including the redirect-to-indirection-id extended community. The 177 redirect-to-indirection-id extended community contains the key 178 (indirection-id type + indirection-id 32-bit value) to select the 179 corresponding next-hop information from the flowpsec client localised 180 indirection-id table. The resulting next-hop information for this 181 use-case is a remote tunnel end-point IP address with accordingly 182 sufficient tunnel encapsulation information to forward the packet 183 accordingly. 185 Requirements: 187 For redirect to shortest path tunnel it is required that the tunnel 188 MUST be operational and allow packets to be exchanged between tunnel 189 head- and tail-end. 191 3.2. Redirection to path-engineered tunnels 193 Possible Indirection-ID type examples: 195 o When deploying on flowspec client a localised Indirection-id 196 table: 0 (localised ID) 198 o When deploying on flowspec client a Segment Routing based 199 Indirection-id table: 6 (Binding Segment ID) 201 Description: 203 For a second use-case, it is expected that the flowspec client 204 redirect traffic matches the flowspec rule, onto a path engineered 205 tunnel. The path engineered tunnel on the flowspec client SHOULD be 206 created by out-of-band mechanisms. Each path engineered tunnel 207 deployed for flowspec redirection, has a unque key as an identifier. 208 consequently, the key (=indirection-id type and indirection-id 32-bit 209 value) uniquely identifies a single path engineered tunnel on the 210 flowspec client. The localised indirection-id mapping table is the 211 collection of all keys corresponding all path engineered tunnels on 212 the flowspec client. 214 For this second use-case scenario, the flowspec controller sends a 215 flowspec route (i.e. flowspec_route#2) to some flowspec clients. The 216 flowspec clients, respectively receive the flowspec route. The 217 redirect-to-indirection-id extended community contains sufficient 218 information for the flowspec clients to select the corresponding 219 path-engineered tunnel and consequently provides sufficient tunnel 220 encapsulation information to redirect the packet according the 221 flowspec controller expectations. 223 Segment Routing Example: 225 A concrete Segment Routing use-case example of this use-case can be 226 found in segment routed networks where path engineered tunnels can be 227 setup by means of a controller signaling explicit paths to peering 228 routers. In such a case, the indirection-id references to a Segment 229 Routing Binding SID, while the indirection-id type references the 230 Bindging SID semantic. The Binding SID is a segment identifier value 231 (as per segment routing definitions in [I-D.draft-ietf-spring- 232 segment-routing] [6]) used to associate with an explicit path and can 233 be setup by a controller using BGP as specified in [I-D.sreekantiah- 234 idr-segment-routing-te] [5] or using PCE as detailed in draft-ietf- 235 pce-segment-routing [7]. When a BGP speaker receives a flow-spec 236 route with a 'redirect to Binding SID' extended community, it 237 installs a traffic filtering rule that matches the packets described 238 by the NLRI field and redirects them to the explicit path associated 239 with the Binding SID. The explicit path is specified as a set/stack 240 of segment identifiers as detailed in the previous documents. The 241 stack of segment identifiers is now imposed on packets matching the 242 flow-spec rule to perform redirection as per the explicit path setup 243 prior. The encoding of the Binding SID value is specified in section 244 4, with the indirection-id field now encoding the associated value 245 for the binding SID. 247 Requirements: 249 For redirect to path engineered tunnels it is required that the 250 engineered tunnel MUST be operational and allow packets to be 251 exchanged between tunnel head- and tail-end. 253 3.3. Redirection to Next-next-hop tunnels 255 Possible Indirection-ID type examples: 257 o When deploying on flowspec client using a localised Indirection-id 258 table the TID (Table ID) is used: one indirection-id community of 259 type 0 (localised ID) with TID=0 and second indirection-id 260 community of type 0 with TID=1 262 Description: 264 A Third use-case is when a BGP Flowspec controller sends a single 265 flowspec policy route to flowspec clients to signal redirection 266 towards next-next-hop tunnels. In this use-case The flowspec rule is 267 instructing the Flowspec client to redirect traffic using a sequence 268 of indirection-id extended communities. The sequence of indirection- 269 ids is managed using Tunnel IDs (TID). 271 Segment Routing Example: 273 i.e. a classic Segment Routing example would be DDoS mitigation 274 towards a Segment Routing Central Egress Path Engineered tunnel [4]. 275 To steer DDoS traffic towards egress peer engineering paths, a first 276 indirection-id (i.e. TID=0) will steer traffic onto a tunnel to an 277 egress router, while the second indirection-id (TID=1) is used steer 278 the egress router arrived traffic onto a pre-identified interface/ 279 peer. The flowspec client will for this use-case in the simpliest 280 implementation dynamically append 2 MPLS labels. A first MPLS label 281 (the outer label) is used to steer the original packet to the egress 282 node, while the next MPLS label (the inner label, corresponding with 283 the indirection-id identified with TID=1) instructs the egress router 284 to steer the original packet to a pre-defined interface/peer 285 corresponding principles documented by [4]. 287 Requirements: 289 To achieve this type of redirection to next-next-hop tunnels, for 290 each flowspec route, multiple indirection-ids, each using a unique 291 Tunnel ID are imposed upon a the flowspec policy rule. It is 292 required that there is synchronisation between the labels used by the 293 Egress Peer Engineering egress router and the flowspec client 294 originally imposing the sequens of EPE Segment Routing segments. It 295 is required that the the engineered next-next-hop tunnel MUST be 296 operational and allow packets to be exchanged between tunnel head- 297 and tail-end. 299 4. Redirect to indirection-id Community 301 This document defines a new BGP extended community known as a 302 Redirect-to-indirection-id extended community. This extended 303 community is a new transitive extended community with the Type and 304 the Sub-Type field to be assigned by IANA. The format of this 305 extended community is show in Figure 1. 307 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 1 308 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 309 | Type | Sub-Type | Flags(1 octet)| Indirection ID| 310 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 311 | Generalized indirection_id | 312 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 314 Figure 1 316 The meaning of the extended community fields are as follows: 318 Type: 1 octet to be assigned by IANA. 320 Sub-Type: 1 octet to be assigned by IANA. 322 Flags: 1 octet field. Following Flags are defined. 324 0 1 325 0 1 2 3 4 5 6 7 326 +-+-+-+-+-+-+-+-+ 327 | RES | TID |C| 328 +-+-+-+-+-+-+-+-+ 330 Figure 2 332 The least-significant Flag bit is defined as the 'C' (or copy) bit. 333 When the 'C' bit is set the redirection applies to copies of the 334 matching packets and not to the original traffic stream. 336 The 'TID' field identifies a 4 bit Table-id field. This field is 337 used to provide the flowspec client an indication how and where to 338 sequence the received indirection-ids to redirecting traffic. TID 339 value 0 indicates that Table-id field is NOT set and SHOULD be 340 ignored. 342 All bits other than the 'C' and 'TID' bits MUST be set to 0 by the 343 originating BGP speaker and ignored by receiving BGP speakers. 345 Indirection ID: 1 octet value. This draft defines following 346 indirection_id Types: 348 0 - Localised ID (The flowspec client uses the received 349 indirection-id to lookup the redirection information in the 350 localised indirection-id table.) 352 1 - Node ID (The flowspec client uses the received indirection-id 353 as a Segment Routing Node ID to redirect traffic towards) 355 2 - Agency ID (The flowspec client uses the received indirection- 356 id as a Segment Routing Agency ID to redirect traffic towards) 358 3 - AS (Autonomous System) ID (The flowspec client uses the 359 received indirection-id as a Segment Routing Autonomous System ID 360 to redirect traffic towards) 362 4 - Anycast ID (The flowspec client uses the received indirection- 363 id as a Segment Routing Anycast ID to redirect traffic towards) 365 5 - Multicast ID (The flowspec client uses the received 366 indirection-id as a Segment Routing Multicast ID to redirect 367 traffic towards) 368 6 - Binding Segment ID (The flowspec client uses the received 369 indirection-id as a Segment Routing Binding Segment ID to redirect 370 traffic towards) [I-D.draft-ietf-spring-segment-routing] [6] 372 7 - VPN ID (The flowspec client uses the received indirection-id 373 as a Segment Routing VPN ID to redirect traffic towards) 375 8 - OAM ID (The flowspec client uses the received indirection-id 376 as a Segment Routing OAM ID to redirect traffic towards) 378 9 - ECMP (Equal Cost Multi-Path) ID (The flowspec client uses the 379 received indirection-id as a Segment Routing PeerSet ID to 380 redirect traffic towards) 382 10 - QoS ID (The flowspec client uses the received indirection-id 383 as a Segment Routing QoS ID to redirect traffic towards) 385 11 - Bandwidth-Guarantee ID (The flowspec client uses the received 386 indirection-id as a Segment Routing Bandwidth-Guarantee ID to 387 redirect traffic towards) 389 12 - Security ID (The flowspec client uses the received 390 indirection-id as a Segment Routing Security ID to redirect 391 traffic towards) 393 13 - Multi-Topology ID (The flowspec client uses the received 394 indirection-id as a Segment Routing Multi-Topology ID to redirect 395 traffic towards) 397 5. Redirect using localised indirection-id mapping table 399 When a BGP speaker receives a flowspec policy route with a 'redirect 400 to indirection-id' extended community and this route represents the 401 one and only best path or an equal cost multipath, it installs a 402 traffic filtering rule that matches the packets described by the NLRI 403 field and redirects them (C=0) or copies them (C=1) towards the 404 indirection-id local recursed path. To construct the local recursed 405 path, the flowspec client does a local indirection-id mapping table 406 lookup (i.e. indirection-id type = 0) using the key comprised of the 407 indirection-id 32-bit value and indirection-id type (=0) to retrieve 408 the correct redirection information. 410 6. Validation Procedures 412 The validation check described in RFC5575 [2] and revised in [3] 413 SHOULD be applied by default to received flow-spec routes with a 414 'redirect to indirection-id' extended community. This means that a 415 flow-spec route with a destination prefix subcomponent SHOULD NOT be 416 accepted from an EBGP peer unless that peer also advertised the best 417 path for the matching unicast route. 419 While it MUST NOT happen, and is seen as invallid combination, it is 420 possible from a semenatics perspective to have multiple clashing 421 redirect actions defined within a single flowspec rule. For best and 422 consistant RFC5575 flowspec redirect behavior the redirect as 423 documented by RFC5575 MUST not be broken, and hence when a clash 424 occurs, then RFC5575 based redirect SHOULD take priority. 425 Additionally, if the 'redirect to indirection-id' does not result in 426 a valid redirection, then the flowspec rule must be processed as if 427 the 'redirect to indirection-id' community was not attached to the 428 flowspec route and MUST provide an indication within the BGP routing 429 table that the respective 'redirect to indirection-id' resulted in an 430 invalid redirection action. 432 7. Security Considerations 434 A system using 'redirect-to-indirection-id' extended community can 435 cause during the redirect mitigation of a DDoS attack result in 436 overflow of traffic received by the mitigation infrastructure. 438 8. Acknowledgements 440 This document received valuable comments and input from IDR working 441 group including Adam Simpson, Mustapha Aissaoui, Jan Mertens, Robert 442 Raszuk, Jeff Haas, Susan Hares and Lucy Yong. 444 9. Contributor Addresses 446 Below is a list of other contributing authors in alphabetical order: 448 Arjun Sreekantiah 449 Cisco Systems 450 170 W. Tasman Drive 451 San Jose, CA 95134 452 USA 454 Email: asreekan@cisco.com 456 Nan Wu 457 Huawei Technologies 458 Huawei Bld., No. 156 Beiquing Rd 459 Beijing 100095 460 China 462 Email: eric.wu@huawei.com 464 Shunwan Zhuang 465 Huawei Technologies 466 Huawei Bld., No. 156 Beiquing Rd 467 Beijing 100095 468 China 470 Email: zhuangshunwan@huawei.com 472 Wim Henderickx 473 Nokia 474 Antwerp 475 BE 477 Email: wim.henderickx@nokia.com 479 Figure 3 481 10. IANA Considerations 483 This document requests a new type and sub-type for the Redirect to 484 indirection-id Extended community from the "Transitive Extended 485 community" registry. The Type name shall be "Redirect to 486 indirection-id Extended Community" and the Sub-type name shall be 487 'Flow-spec Redirect to 32-bit Path-id'. 489 In addition, this document requests IANA to create a new registry for 490 Redirect to indirection-id Extended Community INDIRECTION-IDs as 491 follows: 493 Under "Transitive Extended Community:" 495 Registry: "Redirect Extended Community indirection_id" 497 Reference: [RFC-To-Be] 499 Registration Procedure(s): First Come, First Served 501 Registry: "Redirect Extended Community indirection_id" 503 Value Code Reference 505 0 Localised ID [RFC-To-Be] 506 1 Node ID [RFC-To-Be] 507 2 Agency ID [RFC-To-Be] 508 3 AS (Autonomous System) ID [RFC-To-Be] 509 4 Anycast ID [RFC-To-Be] 510 5 Multicast ID [RFC-To-Be] 511 6 Tunnel ID (Tunnel Binding ID ) [RFC-To-Be] 512 7 VPN ID [RFC-To-Be] 513 8 OAM ID [RFC-To-Be] 514 9 ECMP (Equal Cost Multi-Path) ID [RFC-To-Be] 515 10 QoS ID [RFC-To-Be] 516 11 Bandwidth-Guarantee ID [RFC-To-Be] 517 12 Security ID [RFC-To-Be] 518 13 Multi-Topology ID [RFC-To-Be] 520 Figure 4 522 11. References 524 11.1. Normative References 526 [1] Bradner, S., "Key words for use in RFCs to Indicate 527 Requirement Levels", BCP 14, RFC 2119, March 1997, 528 . 530 [2] Marques, P., Sheth, N., Raszuk, R., Greene, B., Mauch, J., 531 and D. McPherson, "Dissemination of Flow Specification 532 Rules", RFC 5575, DOI 10.17487/RFC5575, August 2009, 533 . 535 11.2. Informative References 537 [3] Uttaro, J., Filsfils, C., Alcaide, J., and P. Mohapatra, 538 "Revised Validation Procedure for BGP Flow 539 Specifications", January 2014. 541 [4] Filsfils, C., Previdi, S., Aries, E., Ginsburg, D., and D. 542 Afanasiev, "Segment Routing Centralized Egress Peer 543 Engineering", October 2015. 545 [5] Sreekantiah, A., Filsfils, C., Previdi, S., Sivabalan, S., 546 Mattes, P., and S. Lin, "Segment Routing Traffic 547 Engineering Policy using BGP", October 2015. 549 [6] Filsfils, C., Previdi, S., Decraene, B., Litkowski, S., 550 Shakir, R., Bashandy, A., Horneffer, M., Henderickx, W., 551 Tantsura, J., Crabbe, E., Milojevic, I., and S. Ytti, 552 "Segment Routing Architecture", December 2015. 554 [7] Sivabalan, S., Medved, M., Filsfils, C., Litkowski, S., 555 Raszuk, R., Bashandy, A., Lopez, V., Tantsura, J., 556 Henderickx, W., Hardwick, J., Milojevic, I., and S. Ytti, 557 "PCEP Extensions for Segment Routing", December 2015. 559 Authors' Addresses 561 Gunter Van de Velde (editor) 562 Nokia 563 Antwerp 564 BE 566 Email: gunter.van_de_velde@nokia.com 568 Keyur Patel 569 Cisco Systems 570 170 W. Tasman Drive 571 San Jose, CA 95134 572 USA 574 Email: keyupate@cisco.com 575 Zhenbin Li 576 Huawei Technologies 577 Huawei Bld., No. 156 Beiquing Rd 578 Beijing 100095 579 China 581 Email: lizhenbin@huawei.com