idnits 2.17.1 draft-ietf-idr-bgpls-inter-as-topology-ext-05.txt: Checking boilerplate required by RFC 5378 and the IETF Trust (see https://trustee.ietf.org/license-info): ---------------------------------------------------------------------------- No issues found here. Checking nits according to https://www.ietf.org/id-info/1id-guidelines.txt: ---------------------------------------------------------------------------- No issues found here. Checking nits according to https://www.ietf.org/id-info/checklist : ---------------------------------------------------------------------------- No issues found here. Miscellaneous warnings: ---------------------------------------------------------------------------- == The copyright year in the IETF Trust and authors Copyright Line does not match the current year -- The document date (September 9, 2019) is 1691 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) ** Obsolete normative reference: RFC 5316 (Obsoleted by RFC 9346) ** Obsolete normative reference: RFC 7752 (Obsoleted by RFC 9552) == Outdated reference: A later version (-12) exists of draft-ietf-teas-native-ip-scenarios-08 Summary: 2 errors (**), 0 flaws (~~), 2 warnings (==), 1 comment (--). Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 2 IDR Working Group A. Wang 3 Internet-Draft China Telecom 4 Intended status: Standards Track H. Chen 5 Expires: March 12, 2020 Futurewei 6 K. Talaulikar 7 Cisco Systems 8 S. Ma 9 Mellanox Technologies 10 September 9, 2019 12 BGP-LS Extension for Inter-AS Topology Retrieval 13 draft-ietf-idr-bgpls-inter-as-topology-ext-05 15 Abstract 17 This document describes the process to build Border Gateway Protocol- 18 Link State (BGP-LS) key parameters in inter-domain scenario, defines 19 one new BGP-LS Network Layer Reachability Information (NLRI) type 20 (Stub Link NLRI) and some new inter Autonomous (inter-AS) Traffic 21 Engineering (TE) related Type-Length-Values (TLVs) for BGP-LS to let 22 Software Definition Network (SDN) controller retrieve the network 23 topology automatically under various inter-AS environments. 25 Such extension and process can enable the network operator to collect 26 the interconnect information between different domains and then 27 calculate the overall network topology automatically based on the 28 information provided by BGP-LS protocol. 30 Status of This Memo 32 This Internet-Draft is submitted in full conformance with the 33 provisions of BCP 78 and BCP 79. 35 Internet-Drafts are working documents of the Internet Engineering 36 Task Force (IETF). Note that other groups may also distribute 37 working documents as Internet-Drafts. The list of current Internet- 38 Drafts is at https://datatracker.ietf.org/drafts/current/. 40 Internet-Drafts are draft documents valid for a maximum of six months 41 and may be updated, replaced, or obsoleted by other documents at any 42 time. It is inappropriate to use Internet-Drafts as reference 43 material or to cite them other than as "work in progress." 45 This Internet-Draft will expire on March 12, 2020. 47 Copyright Notice 49 Copyright (c) 2019 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 (https://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 . . . . . . . . . . . . . . . . . . . . . . . . 2 65 2. Conventions used in this document . . . . . . . . . . . . . . 3 66 3. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3 67 4. Inter-AS Domain Scenarios. . . . . . . . . . . . . . . . . . 3 68 5. Stub Link NLRI . . . . . . . . . . . . . . . . . . . . . . . 4 69 5.1. Inter-AS Native IP Scenario . . . . . . . . . . . . . . . 5 70 5.2. Inter-AS TE Scenario . . . . . . . . . . . . . . . . . . 5 71 6. Inter-AS TE NLRI related TLVs . . . . . . . . . . . . . . . . 6 72 6.1. Remote AS Number TLV . . . . . . . . . . . . . . . . . . 6 73 6.2. IPv4 Remote ASBR ID . . . . . . . . . . . . . . . . . . . 7 74 6.3. IPv6 Remote ASBR ID . . . . . . . . . . . . . . . . . . . 7 75 7. Topology Reconstruction. . . . . . . . . . . . . . . . . . . 8 76 8. Security Considerations . . . . . . . . . . . . . . . . . . . 8 77 9. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 9 78 9.1. New BGP-LS NLRI type . . . . . . . . . . . . . . . . . . 9 79 9.2. New Link Descriptors . . . . . . . . . . . . . . . . . . 9 80 10. Acknowledgement . . . . . . . . . . . . . . . . . . . . . . . 10 81 11. References . . . . . . . . . . . . . . . . . . . . . . . . . 10 82 11.1. Normative References . . . . . . . . . . . . . . . . . . 10 83 11.2. Informative References . . . . . . . . . . . . . . . . . 10 84 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 11 86 1. Introduction 88 BGP-LS [RFC7752] describes the methodology that using BGP protocol to 89 transfer the Link-State information. Such method can enable SDN 90 controller to collect the underlay network topology automatically, 91 but normally it can only get the information within one Interior 92 Gateway Protocol (IGP) domain. If the operator has more than one IGP 93 domain, and these domains interconnect with each other, there is no 94 mechanic within current BGP- LS to transfer the interconnect topology 95 information. 97 Draft [I-D.ietf-idr-bgpls-segment-routing-epe] defines some 98 extensions for exporting BGP peering node topology information 99 (including its peers, interfaces and peering ASs) in a way that is 100 exploitable in order to compute efficient BGP Peering Engineering 101 policies and strategies. Such information can also be used to 102 calculate the interconnection topology among different IGP domains, 103 but it requires every border router to run BGP-LS protocol and report 104 the information to SDN controller. Considering there will be several 105 border routers on the network boundary, such solution restricts its 106 deployment flexibility. 108 This draft analysis the situations that the SDN controller needs to 109 get the interconnected topology information between different AS 110 domains, defines the new Stub Link NLRI and some new TLVs within the 111 BGP-LS protocol to transfer the key information related to them. 112 After that, the SDN controller can then deduce the multi-domain 113 topology automatically based on the information from BGP-LS protocol. 115 2. Conventions used in this document 117 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 118 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this 119 document are to be interpreted as described in RFC 2119 [RFC2119] . 121 3. Terminology 123 The following terms are defined in this document: 125 o IDCs: Internet Data Centers 127 o MAN: Metrio-Area-Network 129 o SDN: Software Definition Network 131 4. Inter-AS Domain Scenarios. 133 Figure 1 illustrates the multi-domain scenarios that this draft 134 discusses. Normally, SDN Controller can get the topology of IGP A 135 and IGP B individually via the BGP-LS protocol, but it can't get the 136 topology connection information between these two IGP domains because 137 there is generally no IGP protocol run on the connected links. 139 +-----------------+ 140 +----+IP SDN Controller+----+ 141 | +-----------------+ | 142 | | 143 |BGP-LS |BGP-LS 144 | | 145 +---------------+-----+ +-----+--------------+ 146 | +--+ +-++ ++-+ +-++ +|-+ +--+| 147 | |S1+--------+S2+---+B1+-----------+B2+---+T1+--------+T2|| 148 | +-++ N1 +-++ ++-+ +-++ ++++ N2 +-++| 149 | | | | | || | | 150 | | | | | || | | 151 | +-++ +-++ ++-+ +-++ ++++ +-++| 152 | |S4+--------+S3+---+B3+-----------+B4+---+T3+--------+T4|| 153 | +--+ +--+ ++-+ +-++ ++-+ +--+| 154 | | | | 155 | | | | 156 | IGP A | | IGP B | 157 +---------------------+ +--------------------+ 159 Figure 1: Inter-AS Domain Scenarios 161 5. Stub Link NLRI 163 [RFC7752] defines four NLRI types(Node NLRI, Link NLRI, IPv4 Topology 164 Prefix NLRI, IPv6 Topology Prefix NLRI) to transfer the topology and 165 prefix information. For inter-as link, the two ends of the link 166 locates in different IGP domains, then it is not appropriate to 167 transfer their information within the current defined NLRI types. 169 This draft defines one new NLRI type, called Stub Link NLRI, which is 170 coded as the following format: 172 0 1 2 3 173 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 1 174 +-+-+-+-+-+-+-+-+ 175 | Protocol-ID | 176 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 177 | Identifier | 178 | (64 bits) | 179 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 180 // Local Node Descriptors (variable) // 181 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 182 // Stub Link Descriptors (variable) // 183 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 185 Figure 2: Stub Link NLRI Format 187 The "Protocol-ID" should be set to the value that indicates "Direct" 188 protocol. 190 The semantics of "Local Node Descriptors" and "Stub Link Descriptors" 191 are same as that defined in [RFC7752] for "Node Descriptors" and 192 "Link Descriptor". 194 This newly defined NLRI can be used to describe the link that has 195 only one end located within the IGP domain, as described in the 196 following sections. 198 5.1. Inter-AS Native IP Scenario 200 Draft [I-D.ietf-teas-native-ip-scenarios] describes the situation 201 that operator needs some traffic engineering solution for the inter- 202 as native IP environment. In such situation, different domain may 203 run different IGP protocol. The operator needs to know the inter-as 204 topology first to calculate the end to end optimal path centrally. 206 When IGP A or IGP B in Figure 1 runs native IS-IS/OSPF protocol, the 207 operator can use passive feature for the inter-domain links to let 208 the routers within the IGP domain know these links. Such stub links 209 information can then be carried within the Stub Link NLRI reported 210 via the BGP-LS protocol to the SDN controller. 212 The "Local Node Descriptors" should describe the characteristics of 213 ASBRs that are connected these stub links. 215 When such information is reported via the BGP-LS protocol, the SDN 216 controller can construct the underlay inter-domain topology according 217 to procedure described in Section 7 219 5.2. Inter-AS TE Scenario 221 When IGP A or IGP B in Figure 1 runs IS-IS TE/OSPF-TE 222 protocol,[RFC5316] and [RFC5392] define IS-IS and OSPF extensions 223 respectively to deal with the situation for inter-AS traffic 224 engineering. Three new sub-TLVs(Remote AS Number、IPv4 Remote 225 ASBR ID、IPv6 Remote ASBR ID) which are associated with the 226 inter-AS TE link are defined. 228 These TLVs are flooded within the IGP domain automatically. They 229 should be carried within the newly defined Stub Link NLRI within the 230 BGP-LS protocol, as the descriptors for the inter-AS stub link. 232 The "Local Node Descriptors" should describe the the characteristics 233 of ASBRs that are connected these inter-AS TE links. 235 If the SDN controller knows these information via one of the interior 236 router that runs BGP-LS protocol, the SDN controller can rebuild the 237 inter-AS TE topology correctly according to the procedure described 238 in Section 7 240 6. Inter-AS TE NLRI related TLVs 242 This draft proposes to add three new TLVs that is included within the 243 Stub Link NLRI to transfer the information via BGP-LS, which are 244 required to build the inter-AS TE related topology by the SDN 245 controller. 247 The following Link Descriptor TLVs are added into the BGP-LS protocol 248 : 250 +-----------+---------------------+--------------+----------------+ 251 | TLV Code | Description |IS-IS/OSPF TLV| Reference | 252 | Point | | /Sub-TLV | (RFC/Section) | 253 +-----------+---------------------+--------------+----------------+ 254 | TBD |Remote AS Number | 24/21 | [RFC5316]/3.3.1| 255 | | | | [RFC5392]/3.3.1| 256 | TBD |IPv4 Remote ASBR ID | 25/22 | [RFC5316]/3.3.2| 257 | | | | [RFC5392]/3.3.2| 258 | TBD |IPv6 Remote ASBR ID | 26/24 | [RFC5316]/3.3.3| 259 | | | | [RFC5392]/3.3.3| 260 +-----------+---------------------+--------------+----------------+ 261 Figure 3: Link Descriptor TLVs 263 Detail encoding of these TLVs are synchronized with the corresponding 264 parts in [RFC5316] and [RFC5392], which keeps the BGP-LS protocol 265 agnostic to the underly protocol. 267 6.1. Remote AS Number TLV 269 A new TLV, the remote AS number TLV, is defined for inclusion in the 270 link descriptor when advertising inter-AS TE links. The remote AS 271 number TLV specifies the AS number of the neighboring AS to which the 272 advertised link connects. 274 The remote AS number TLV is TLV type TBD (seeSection 9 ) and is 4 275 octets in length. The format is as follows: 277 0 1 2 3 278 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 1 279 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 280 | Type | Length | 281 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 282 | Remote AS Number | 283 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 284 Figure 4: Remote AS Number TLV Format 286 The Remote AS number field has 4 octets. When only 2 octets are used 287 for the AS number, as in current deployments, the left (high-order) 2 288 octets MUST be set to 0. The remote AS number TLV MUST be included 289 when a router advertises an inter-AS TE link. 291 6.2. IPv4 Remote ASBR ID 293 A new TLV, which is referred to as the IPv4 remote ASBR ID TLV, is 294 defined for inclusion in the link descriptor when advertising inter- 295 AS TE links. The IPv4 remote ASBR ID TLV specifies the IPv4 296 identifier of the remote ASBR to which the advertised inter-AS link 297 connects. This could be any stable and routable IPv4 address of the 298 remote ASBR. Use of the TE Router ID as specified in the Traffic 299 Engineering router ID TLV [RFC5305] is RECOMMENDED. 301 The IPv4 remote ASBR ID TLV is TLV type TBD (see Section 9) and is 4 302 octets in length. The format of the IPv4 remote ASBR ID sub-TLV is 303 as follows: 305 0 1 2 3 306 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 1 307 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 308 | Type | Length | 309 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 310 | Remote ASBR ID | 311 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 312 Figure 5: IPv4 Remote ASBR ID TLV Format 314 The IPv4 remote ASBR ID TLV MUST be included if the neighboring ASBR 315 has an IPv4 address. If the neighboring ASBR does not have an IPv4 316 address (not even an IPv4 TE Router ID), the IPv6 remote ASBR ID TLV 317 MUST be included instead. An IPv4 remote ASBR ID TLV and IPv6 remote 318 ASBR ID TLV MAY both be present in an inter-AS TE link NLRI. 320 6.3. IPv6 Remote ASBR ID 322 A new TLV, which is referred to as the IPv6 remote ASBR ID TLV, is 323 defined for inclusion in the link descriptor when advertising inter- 324 AS links. The IPv6 remote ASBR ID TLV specifies the IPv6 identifier 325 of the remote ASBR to which the advertised inter-AS link connects. 326 This could be any stable and routable IPv6 address of the remote 327 ASBR. Use of the TE Router ID as specified in the IPv6 Traffic 328 Engineering router ID TLV [RFC6119] is RECOMMENDED. 330 The IPv6 remote ASBR ID TLV is TLV type TBD (see Section 9) and is 16 331 octets in length. The format of the IPv6 remote ASBR ID TLV is as 332 follows: 334 0 1 2 3 335 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 1 336 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 337 | Type | Length | 338 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 339 | Remote ASBR ID | 340 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 341 | Remote ASBR ID (continued) | 342 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 343 | Remote ASBR ID (continued) | 344 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 345 | Remote ASBR ID (continued) | 346 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 347 Figure 6: IPv6 Remote ASBR ID TLV Format 349 The IPv6 remote ASBR ID TLV MUST be included if the neighboring ASBR 350 has an IPv6 address. If the neighboring ASBR does not have an IPv6 351 address, the IPv4 remote ASBR ID TLV MUST be included instead. An 352 IPv4 remote ASBR ID TLV and IPv6 remote ASBR ID TLV MAY both be 353 present in an inter-AS TE link NLRI. 355 7. Topology Reconstruction. 357 When SDN Controller gets such information from BGP-LS protocol, it 358 should compares the proximity of these stub links. If they are under 359 the same network scope, then it should find the corresponding 360 associated router information, build the link between these two 361 border routers. 363 After iterating the above procedures for all of the stub links, the 364 SDN controller can then retrieve the connection topology between 365 different domains automatically. 367 8. Security Considerations 369 It is common for one operator to occupy several IGP domains that are 370 composited by its backbone network and several MAN(Metrio-Area- 371 Network)s/Internet Data Centers (IDCs). When they do traffic 372 engineering which spans MAN, Backbone and IDC, they need to know the 373 inter-as topology via the process described in this draft. Using the 374 passive interface features or configuring the Traffic Engineering 375 (TE) parameters on the interconnect links will not spread the 376 topology fluctuation across each other domain. 378 9. IANA Considerations 380 This document defines: 382 o A new BGP NLRI Type: Stub Link NLRI. The codepoint is from the 383 "BGP-LS NLRI Types" 385 o Three new Link Descriptors TLV: Remote AS Number TLV, IPv4 Remote 386 ASBR ID, IPv6 Remote ASBR ID. The codepoint are from "BGP-LS Node 387 Descriptor, Link Descriptor, Prefix Descriptor, and Attribute 388 TLVs" registry. 390 9.1. New BGP-LS NLRI type 392 This document defines a new value in the registry "BGP-LS NLRI 393 Types": 395 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 396 | Code Point | Description | Status | 397 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 398 | TBD | Stub Link NLRI | Allocation from IANA | 399 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 400 Figure 7: Stub Link NLRI Codepoint 402 9.2. New Link Descriptors 404 This document defines three new values in the registry "BGP-LS Node 405 Descriptor, Link Descriptor, Prefix Descriptor, and Attribute TLVs": 407 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 408 | Code Point | Description | Status | 409 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 410 | TBD | Remote AS Number | Allocation from IANA | 411 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 412 | TBD |IPv4 Remote ASBR ID| Allocation from IANA | 413 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 414 | TBD |IPv6 Remote ASBR ID| Allocation from IANA | 415 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 416 Figure 8: BGP-LS Link Descriptors TLV 418 10. Acknowledgement 420 The author would like to thank Acee Lindem, Jie Dong, Jeff Tantsura 421 and Dhruv Dhody for their valuable comments and suggestions. 423 11. References 425 11.1. Normative References 427 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 428 Requirement Levels", BCP 14, RFC 2119, 429 DOI 10.17487/RFC2119, March 1997, 430 . 432 [RFC5305] Li, T. and H. Smit, "IS-IS Extensions for Traffic 433 Engineering", RFC 5305, DOI 10.17487/RFC5305, October 434 2008, . 436 [RFC5316] Chen, M., Zhang, R., and X. Duan, "ISIS Extensions in 437 Support of Inter-Autonomous System (AS) MPLS and GMPLS 438 Traffic Engineering", RFC 5316, DOI 10.17487/RFC5316, 439 December 2008, . 441 [RFC5392] Chen, M., Zhang, R., and X. Duan, "OSPF Extensions in 442 Support of Inter-Autonomous System (AS) MPLS and GMPLS 443 Traffic Engineering", RFC 5392, DOI 10.17487/RFC5392, 444 January 2009, . 446 [RFC6119] Harrison, J., Berger, J., and M. Bartlett, "IPv6 Traffic 447 Engineering in IS-IS", RFC 6119, DOI 10.17487/RFC6119, 448 February 2011, . 450 [RFC7752] Gredler, H., Ed., Medved, J., Previdi, S., Farrel, A., and 451 S. Ray, "North-Bound Distribution of Link-State and 452 Traffic Engineering (TE) Information Using BGP", RFC 7752, 453 DOI 10.17487/RFC7752, March 2016, 454 . 456 11.2. Informative References 458 [I-D.ietf-idr-bgpls-segment-routing-epe] 459 Previdi, S., Talaulikar, K., Filsfils, C., Patel, K., Ray, 460 S., and J. Dong, "BGP-LS extensions for Segment Routing 461 BGP Egress Peer Engineering", draft-ietf-idr-bgpls- 462 segment-routing-epe-19 (work in progress), May 2019. 464 [I-D.ietf-teas-native-ip-scenarios] 465 Wang, A., Huang, X., Qou, C., Li, Z., and P. Mi, 466 "Scenarios and Simulation Results of PCE in Native IP 467 Network", draft-ietf-teas-native-ip-scenarios-08 (work in 468 progress), August 2019. 470 Authors' Addresses 472 Aijun Wang 473 China Telecom 474 Beiqijia Town, Changping District 475 Beijing, Beijing 102209 476 China 478 Email: wangaj3@chinatelecom.cn 480 Huaimo Chen 481 Futurewei 482 Boston, MA 483 USA 485 Email: hchen@futurewei.com 487 Ketan Talaulikar 488 Cisco Systems 490 Email: ketant@cisco.com 492 Shaowen Ma 493 Mellanox Technologies 495 Email: mashaowen@gmail.com