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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: o The MPLS Label field in the BIER PTA of the BGP-MVPN x-PMSI A-D route MUST be ignored and MUST not be used for the identification of the VRF. -- The document date (January 14, 2020) is 1563 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to lower-maturity documents in RFCs) == Missing Reference: 'RFC8114' is mentioned on line 315, but not defined == Outdated reference: A later version (-15) exists of draft-ietf-bess-srv6-services-01 == Outdated reference: A later version (-28) exists of draft-ietf-spring-srv6-network-programming-07 == Outdated reference: A later version (-10) exists of draft-xie-bier-ipv6-encapsulation-04 Summary: 1 error (**), 0 flaws (~~), 6 warnings (==), 1 comment (--). Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 2 Network Working Group J. Xie 3 Internet-Draft Huawei Technologies 4 Intended status: Standards Track M. McBride 5 Expires: July 17, 2020 Futurewei 6 S. Dhanaraj 7 Huawei Technologies 8 L. Geng 9 China Mobile 10 January 14, 2020 12 Use of BIER IPv6 Encapsulation (BIERv6) for Multicast VPN in IPv6 13 networks 14 draft-xie-bier-ipv6-mvpn-02 16 Abstract 18 This draft defines the procedures and messages for using Bit Index 19 Explicit Replication (BIER) for Multicast VPN Services in IPv6 20 networks using the BIER IPv6 encapsulation. It provides a migration 21 path for Multicast VPN service using BIER MPLS encapsulation in MPLS 22 networks to multicast VPN service using BIER IPv6 encapsulation 23 (BIERv6) in IPv6 networks. 25 Requirements Language 27 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 28 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this 29 document are to be interpreted as described in [RFC2119] and 30 [RFC8174]. 32 Status of This Memo 34 This Internet-Draft is submitted in full conformance with the 35 provisions of BCP 78 and BCP 79. 37 Internet-Drafts are working documents of the Internet Engineering 38 Task Force (IETF). Note that other groups may also distribute 39 working documents as Internet-Drafts. The list of current Internet- 40 Drafts is at https://datatracker.ietf.org/drafts/current/. 42 Internet-Drafts are draft documents valid for a maximum of six months 43 and may be updated, replaced, or obsoleted by other documents at any 44 time. It is inappropriate to use Internet-Drafts as reference 45 material or to cite them other than as "work in progress." 47 This Internet-Draft will expire on July 17, 2020. 49 Copyright Notice 51 Copyright (c) 2020 IETF Trust and the persons identified as the 52 document authors. All rights reserved. 54 This document is subject to BCP 78 and the IETF Trust's Legal 55 Provisions Relating to IETF Documents 56 (https://trustee.ietf.org/license-info) in effect on the date of 57 publication of this document. Please review these documents 58 carefully, as they describe your rights and restrictions with respect 59 to this document. Code Components extracted from this document must 60 include Simplified BSD License text as described in Section 4.e of 61 the Trust Legal Provisions and are provided without warranty as 62 described in the Simplified BSD License. 64 Table of Contents 66 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 67 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3 68 3. Use of PTA and Prefix-SID Attribute in x-PMSI A-D Routes . . 4 69 4. MVPN over BIERv6 Core . . . . . . . . . . . . . . . . . . . . 4 70 5. GTM over BIERv6 Core . . . . . . . . . . . . . . . . . . . . 6 71 6. Data Plane . . . . . . . . . . . . . . . . . . . . . . . . . 7 72 6.1. Encapsulation of Multicast Traffic . . . . . . . . . . . 7 73 6.2. MTU . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 74 6.3. TTL . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 75 7. Security Considerations . . . . . . . . . . . . . . . . . . . 9 76 8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 9 77 9. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 9 78 10. References . . . . . . . . . . . . . . . . . . . . . . . . . 9 79 10.1. Normative References . . . . . . . . . . . . . . . . . . 10 80 10.2. Informative References . . . . . . . . . . . . . . . . . 11 81 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 11 83 1. Introduction 85 Bit Index Explicit Replication (BIER) [RFC8279] is an architecture 86 that provides optimal multicast forwarding without requiring 87 intermediate routers to maintain any per-flow state by using a 88 multicast-specific BIER header. BIERv6 refers to the deployment of 89 BIER in IPv6 networks using the BIER IPv6 encapsulation format 90 defined in [I-D.xie-bier-ipv6-encapsulation]. 92 This document describes a method to realize MVPN services using BIER 93 as a P-tunnel in the IPv6 Networks (BIERv6 Networks). It defines a 94 method to use an IPv6 address, called Src.DTx in this document, as 95 source address of an IPv6 header, to identify the MVPN instance at 96 the Egress PE. The Src.DTx address used as source address of a 97 BIERv6 packet represent both the context and the upstream-assigned 98 VPN Label in MVPN scenario defined in [RFC8556]. 100 The Src.DTx address can be a normal IPv6 address of the BFR, for 101 example, a loopback address of the BFR. The Src.DTx address can also 102 be an IPv6 address allocated from an IPv6 address block, for example, 103 an IPv6 address allocated from an SRv6 locator if BIERv6 MVPN is 104 deployed in an SRv6 network. 106 In particular, MVPN deployment in IPv6 networks relies on L3VPN 107 deployment on IPv6 networks firstly, thus the c-multicast routing 108 procedure like UMH Selection can be done. As an example, the L3VPN 109 deployment in SRv6 networks can be referred to 110 [I-D.ietf-bess-srv6-services]. 112 GTM defined in [RFC7716] is also covered in this document, as GTM 113 shares the same BGP-MVPN signaling, while providing an approach of 114 Non-VPN multicast over a service provider core with various P-tunnel 115 type. For the same reason of UMH selection as a base of GTM, the 116 Global IPv4/IPv6 over SRv6 networks can be referred to 117 [I-D.ietf-bess-srv6-services]. 119 2. Terminology 121 Readers of this document are assumed to be familiar with the 122 terminology and concepts of the documents listed as Normative 123 References. Additionally the following terms are used through out 124 the document. 126 o BIERv6 - BIER in IPv6 networks using the BIERv6 encapsulation 127 format defined in [I-D.xie-bier-ipv6-encapsulation]. 129 o SRv6 - Segment Routing instantiated on the IPv6 dataplane as 130 defined in [I-D.ietf-spring-srv6-network-programming]. 132 o SRv6 SID - SRv6 Segment Identifier as defined in 133 [I-D.ietf-spring-srv6-network-programming]. 135 o End.DTx - Refers to the functions End.DT6, End.DT4, End.DT46 136 defined in [I-D.ietf-spring-srv6-network-programming]. 138 o Src.DTx - Refers to the functions Src.DT4, Src.DT6, Src.DT46 139 defind in this document. 141 o SRv6 L3 Service - L3VPN/Global-L3 service in SRv6 networks defined 142 in [I-D.ietf-bess-srv6-services], or MVPN/GTM service in BIERv6 143 networks defined in this document. 145 3. Use of PTA and Prefix-SID Attribute in x-PMSI A-D Routes 147 The BGP-MVPN I-PMSI A-D (Type 1) or S-PMSI A-D (Type 3) route (called 148 x-PMSI A-D route in this document), advertised by Ingress PE carries 149 the BIER (Type 11) PTA as specified in [RFC8556]. The BIER PTA 150 carried in the x-PMSI A-D route is used for explicitly tracking the 151 receiver-site PEs which are interested in a specific multicast flow. 152 It includes three BIER-specific fields, Sub-domain-id, BFR-id, and 153 BFR-prefix. For BIER P-tunnel using the BIERv6 encapsulation in IPv6 154 networks, the BFR-prefix field in the PTA MUST be set to the BFIR 155 IPv6 prefix and the MPLS Label field in the PTA MUST set to 0. For 156 MVPN over BIERv6, the Src.DTx IPv6 address of the BFIR is used to 157 identify the VRF instead of an MPLS Label. The Src.DTx IPv6 Address 158 (Src.DT6 or Src.DT4 or Src.DT46) MUST be carried within an SRv6 L3 159 Service TLV [I-D.ietf-bess-srv6-services] of BGP Prefix-SID attribute 160 in the x-PMSI A-D route. 162 The Ingress PE encapsulates the c-multicast IP packet with BIERv6 163 header and the source address in the outer IPv6 header will be set to 164 the Src.DTx IPv6 address advertised in the BGP-MVPN x-PMSI A-D 165 routes. See section 3 of [I-D.xie-bier-ipv6-encapsulation] for the 166 detailed packet format. 168 Egress PE (BFER) receiving the x-PMSI A-D routes with BIER PTA and 169 SRv6 L3 Service TLV learns the Src.DTx IPv6 address and uses it to 170 identify the VRF of the c-multicast packet. 172 When Egress PE receives a BIERv6 packet and the self bfr-id is set in 173 the bit-string field of the BIERv6 header, it retrieves the Src.DTx 174 IPv6 address from the source address of the IPv6 header to determine 175 the VRF and the Address Family (AF) of the c-multicast data packet, 176 and performs the MFIB lookup in the corresponding table. 178 4. MVPN over BIERv6 Core 180 [RFC8556] specifies the protocol and procedures to be followed by the 181 Ingress and Egress PEs to use BIER as a P-tunnel for MVPN in MPLS 182 networks. This section specifies the required changes and procedures 183 in addition to support BIER as a P-tunnel in IPv6 networks using 184 BIERv6. 186 In a IPv6 service provider network, many of the IP address fields 187 used in the BGP-MVPN routes are IPv6 address as specified in 188 [RFC6515]. These are listed below. 190 o "Originating Router's IP Address" in the NLRI of Type 1 or Type 3 191 BGP-MVPN route is an IPv6 address. 193 o "Network Address of Next Hop" field in the MP_REACH_NLRI attribute 194 is an IPv6 address. 196 o Route Targets Extended Community (EC) used in C-multicast join 197 (Type 6 or 7) route or Leaf A-D (Type 5) route is an IPv6 Address 198 Specific Extended Community, where the Global Administrator field 199 will be an IPv6 address identifies the Upstream PE or the UMH. 201 o "VRF Route Import Extended Community (EC)" carried by unicast VPN- 202 IPv4 or VPN-IPv6 routes as [RFC6515] specifies, or SAFI 1, 2, or 4 203 unicast routes, or MVPN (SAFI 5) Source-Active routes as [RFC7716] 204 specifies. 206 On the Ingress PE (BFIR), the BGP-MVPN x-PMSI A-D route is 207 constructed as per the procedures specified in [RFC8556] and with the 208 following specifications. 210 o MPLS Label field in the BIER PTA MUST be set to Zero. 212 o BFR-prefix field in the BIER PTA MUST be set to the Ingress PEs 213 (BFIR) IPv6 BFR-Prefix Address. It does not need to be the same 214 as the other IPv6 address of the x-PMSI AD route. 216 o Route MUST also carry an BGP Prefix SID attribute with an SRv6 L3 217 Service TLV carrying an Src.DTx IPv6 address uniquely identifying 218 the MVPN instance. 220 If the MVPN is IPv4 MVPN, the Src.DTx can be either Src.DT4 or 221 Src.DT46. If the MVPN is IPv6 MVPN, the Src.DTx can be either 222 Src.DT6 or Src.DT46. The distribution of the x-PMSI A-D routes uses 223 the Src.DTx according to the local configuration, and is independent 224 to the use of End.DTx in VPN-IP unicast routes of this VPN. For 225 example, one can use End.DT46 for VPNv4 and VPNv6 unicast routes, but 226 use Src.DT4 for the MVPN routes for the same VPN. Another example, 227 one can use End.DX for VPNv4 unicast routes, but use Src.DT46 for the 228 MVPN routes for the same VPN. 230 BFIR MAY carry the BGP Prefix-SID attribute only in I-PMSI A-D route 231 when I-PMSI A-D route is used, while other S-PMSI A-D routes do not 232 carry the BGP Prefix-SID attribute. 234 BFIR MAY carry the BGP Prefix-SID attribute only in wildcard S-PMSI 235 A-D routes when the "S-PMSI Only" mode as described in [RFC6625] is 236 used, while other S-PMSI A-D routes do not carry the BGP Prefix-SID 237 attribute. 239 On the Egress PE (BFER), the BGP-MVPN x-PMSI A-D route is processed 240 as per the procedures specified in [RFC8556] and with the following 241 specifications: 243 o The MPLS Label field in the BIER PTA of the BGP-MVPN x-PMSI A-D 244 route MUST be ignored and MUST not be used for the identification 245 of the VRF. 247 o The BGP-MVPN x-PMSI A-D route MUST be dropped if the BFR-prefix 248 field in the BIER PTA is not an IPv6 address. 250 o The BGP-MVPN x-PMSI A-D route MUST be dropped if it does not carry 251 a Src.DTx IPv6 address in the SRv6 L3 Service TLV in BGP Prefix 252 SID attribute. 254 o Leaf A-D route originated by the Egress PE (BFER) MUST carry the 255 BIER PTA with the BFR-prefix field set to the BFER IPv6 BFR- 256 prefix. 258 Valid BGP-MVPN x-PMSI A-D route received by an Egress PE (BFER) is 259 stored locally, and the Src.DTx IPv6 Address carried in the SRv6 L3 260 service TLV is used to identify the VRF of a c-multicast data packet. 261 This may be populated into forwarding table only when there is 262 c-multicast flow state with UMH of the specific BFIR this Src.DTx 263 located in. 265 If more than one x-PMSI A-D routes belonging to the same VRF has 266 different Src.DTx value, the processing is determined by the local 267 policy of the BFER. 269 If more than one x-PMSI A-D routes belonging to different VRF has the 270 same Src.DTx value, the BFER must log an error, and a BIERv6 packet 271 with this Src.DTx as the IPv6 source address MUST be dropped. 273 The BGP Prefix-SID attribute (which may include the Src.DTx in SRv6 274 L3 Service TLV) MUST NOT be carried in Leaf A-D route upon sending, 275 and MUST be ignored upon reception. 277 5. GTM over BIERv6 Core 279 As specified in [RFC7716], Global Table Multicast (GTM) uses the same 280 Subsequent Address Family Identifier (SAFI) value, the same Network 281 Layer Reachability Information (NLRI) format, and the same procedures 282 of MVPN with only a few adaptions. It support for both IPv4 and IPv6 283 multicast flows over either an IPv4 or IPv6 SP infrastructure. GTM 284 over BIERv6 core is obviously a case of IPv4/IPv6 multicast over an 285 IPv6 SP infrastructure with BIERv6 data-plane. 287 The BIER (Type 11) PTA attribute and the BGP Prefix-SID attribute are 288 carried in the x-PMSI A-D route in GTM cases. When the a BGP-MVPN 289 x-PMSI A-D route is received by Egress PE, it is stored locally, and 290 the Src.DTx IPv6 Address of the Ingress PE in the route is used to 291 determine the VRF of a packet, which is the 'public' VRF in the case 292 of GTM. 294 There are some other attributes listed below for GTM over a BIERv6 295 core: 297 o Route Distinguishers - the RD field of a BGP-MVPN route's NLRI 298 MUST be set to zero (i.e., to 64 bits of zero) to represent a Non- 299 VPN GTM. See section 2.2 of [RFC7716]. 301 o Route Targets Extended Community (EC) - The RT EC carried by the 302 BGP-MVPN C-multicast (Type 6 or 7) route or Leaf A-D (Type 4) 303 route MUST be an IPv6-address-specific Extended Community (EC). 304 The Global Administrator field identifies the Upstream PE or the 305 UMH, and the Local Administrator field MUST always be set to zero 306 in GTM case. 308 o VRF Route Import Extended Community (EC) - The VRF Route Import EC 309 used in BIERv6 core MUST be an IPv6-address-specific EC if used, 310 either used in UMH-eligible unicast routes having a SAFI of 1, 2, 311 or 4, or used in the MVPN (SAFI of 5) Source Active A-D route. 313 GTM IPv4 multicast over an BIERv6 core may be considered an 314 alternative to support IPv4 IPTV content delivery during transition 315 to IPv6 period comparing to [RFC8114]. They both use IPv4-in-IPv6 316 encapsulation, while BIERv6 uses an additional BIER header within an 317 IPv6 Extension header to support stateless core. 319 6. Data Plane 321 6.1. Encapsulation of Multicast Traffic 323 BIER IPv6 encapsulation (BIERv6) [I-D.xie-bier-ipv6-encapsulation] is 324 used for forwarding the c-multicast traffic through an IPv6 core. 325 The following diagram shows the progression of an MVPN c-multicast 326 packet as it enters and leaves the intra-AS service-provider network. 328 +---------------+ +---------------+ 329 | P-IPv6 Header | | P-IPv6 Header | 330 | (SA=Src.DTx | | (SA=Src.DTx | 331 | DA=End.BIER) | | DA=End.BIER) | 332 +---------------+ +---------------+ 333 | P-IPv6 ExtHdr | | P-IPv6 ExtHdr | 334 | (BIER header) | | (BIER header) | 335 ++=========++ ++=============++ ++=============++ ++=========++ 336 ||C-IP Hdr || || C-IP Hdr || || C-IP Hdr || ||C-IP Hdr || 337 ++=========++ >> ++=============++ >> ++=============++ >> ++=========++ 338 ||C-Payload|| || C-Payload || || C-Payload || ||C-Payload|| 339 ++=========++ ++=============++ ++=============++ ++=========++ 340 CE1-----------PE1------------------P2------------------PE2-----------CE2 342 Figure 1: BIERv6 MVPN/GTM Intra-AS 344 In case of inter-AS scenario, BIERv6 packets may travel through 345 unicast to a Boarder Router (BR), and then replicate in a single 346 intra-AS BIERv6 domain. How such non-segmented BIERv6 scenario can 347 be supported is outside the scope of this document. 349 How segmented MVPN, for example, between BIERv6 and BIERv6, or 350 between BIERv6 and Ingress Replication(IR) in Non-MPLS IPv6 networks, 351 is outside the scope of this document. 353 The Src.DTx SHOULD support as destination address of an ICMPv6 354 packet. If a loopback address of the BFR is used as Src.DTx address, 355 this is supported. If an address from an SRv6 locator is used as 356 Src.DTx address, the following pseudo-code describes how a packet 357 with Src.DTx as destination address is handled: 359 1. IF Last_NH = ICMPv6 ;;Ref1 360 2. Send to CPU. 361 3. ELSE 362 4. Drop the packet. 364 Ref1: ICMPv6 packet using Src.DT4, Src.DT6 or Src.DT46 as destination 365 address. 367 6.2. MTU 369 Each BFIR is expected to know the Maximum Transmission Unit (MTU) of 370 the BIER domain. This may be known by provisioning, or by method 371 specified in [draft-ietf-bier-mtud]. The section 3 of [RFC8296] 372 applies. 374 6.3. TTL 376 The ingress PE (BFIR) should not copy the Time to Live (TTL) field 377 from the payload IP header received from a CE router to the delivery 378 IP header. Setting the TTL of the delivery IP header is determined 379 by the local policy of the ingress PE (BFIR) router per section 3 of 380 [RFC8296]. 382 7. Security Considerations 384 The security considerations SEC-1, SEC-2, SEC-3 defined in 385 [I-D.ietf-spring-srv6-network-programming] apply equally to this 386 document. 388 8. IANA Considerations 390 Allocation is expected from IANA for the following Src.DTx functions 391 codepoints from the "SRv6 Endpoint Behaviors" sub-registry. 393 Values 68, 69, 70 is suggested for Src.DT6, Src.DT4, Src.DT46 394 respectively. 396 +-------+--------+--------------------------+------------+ 397 | Value | Hex | Endpoint function | Reference | 398 +-------+--------+--------------------------+------------+ 399 | TBD | TBD | Src.DT6 | This draft | 400 +-------+--------+--------------------------+------------+ 401 | TBD | TBD | Src.DT4 | This draft | 402 +-------+--------+--------------------------+------------+ 403 | TBD | TBD | Src.DT46 | This draft | 404 +-------+--------+--------------------------+------------+ 406 Src.DT6 Source address indicating decapsulation and IPv6 table lookup 407 e.g. IPv6-MVPN (equivalent to per-VRF VPN label in RFC8556) 408 Src.DT4 Source address indicating decapsulation and IPv4 table lookup 409 e.g. IPv4-MVPN (equivalent to per-VRF VPN label in RFC8556) 410 Src.DT46 Source address indicating decapsulation and IP table lookup 411 e.g. IP-MVPN (equivalent to per-VRF VPN label) 413 9. Acknowledgements 415 TBD. 417 10. References 418 10.1. Normative References 420 [I-D.ietf-bess-srv6-services] 421 Dawra, G., Filsfils, C., Raszuk, R., Decraene, B., Zhuang, 422 S., and J. Rabadan, "SRv6 BGP based Overlay services", 423 draft-ietf-bess-srv6-services-01 (work in progress), 424 November 2019. 426 [I-D.ietf-spring-srv6-network-programming] 427 Filsfils, C., Camarillo, P., Leddy, J., Voyer, D., 428 Matsushima, S., and Z. Li, "SRv6 Network Programming", 429 draft-ietf-spring-srv6-network-programming-07 (work in 430 progress), December 2019. 432 [I-D.xie-bier-ipv6-encapsulation] 433 Xie, J., Geng, L., McBride, M., Asati, R., and S. 434 Dhanaraj, "Encapsulation for BIER in Non-MPLS IPv6 435 Networks", draft-xie-bier-ipv6-encapsulation-04 (work in 436 progress), December 2019. 438 [RFC6515] Aggarwal, R. and E. Rosen, "IPv4 and IPv6 Infrastructure 439 Addresses in BGP Updates for Multicast VPN", RFC 6515, 440 DOI 10.17487/RFC6515, February 2012, 441 . 443 [RFC6625] Rosen, E., Ed., Rekhter, Y., Ed., Hendrickx, W., and R. 444 Qiu, "Wildcards in Multicast VPN Auto-Discovery Routes", 445 RFC 6625, DOI 10.17487/RFC6625, May 2012, 446 . 448 [RFC7716] Zhang, J., Giuliano, L., Rosen, E., Ed., Subramanian, K., 449 and D. Pacella, "Global Table Multicast with BGP Multicast 450 VPN (BGP-MVPN) Procedures", RFC 7716, 451 DOI 10.17487/RFC7716, December 2015, 452 . 454 [RFC8279] Wijnands, IJ., Ed., Rosen, E., Ed., Dolganow, A., 455 Przygienda, T., and S. Aldrin, "Multicast Using Bit Index 456 Explicit Replication (BIER)", RFC 8279, 457 DOI 10.17487/RFC8279, November 2017, 458 . 460 [RFC8296] Wijnands, IJ., Ed., Rosen, E., Ed., Dolganow, A., 461 Tantsura, J., Aldrin, S., and I. Meilik, "Encapsulation 462 for Bit Index Explicit Replication (BIER) in MPLS and Non- 463 MPLS Networks", RFC 8296, DOI 10.17487/RFC8296, January 464 2018, . 466 [RFC8556] Rosen, E., Ed., Sivakumar, M., Przygienda, T., Aldrin, S., 467 and A. Dolganow, "Multicast VPN Using Bit Index Explicit 468 Replication (BIER)", RFC 8556, DOI 10.17487/RFC8556, April 469 2019, . 471 10.2. Informative References 473 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 474 Requirement Levels", BCP 14, RFC 2119, 475 DOI 10.17487/RFC2119, March 1997, 476 . 478 [RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 479 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, 480 May 2017, . 482 Authors' Addresses 484 Jingrong Xie 485 Huawei Technologies 487 Email: xiejingrong@huawei.com 489 Mike McBride 490 Futurewei 492 Email: mmcbride7@gmail.com 494 Senthil Dhanaraj 495 Huawei Technologies 497 Email: senthil.dhanaraj@huawei.com 499 Liang Geng 500 China Mobile 502 Email: gengliang@chinamobile.com