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The disclaimer is usually necessary only for documents that revise or obsolete older RFCs, and that take significant amounts of text from those RFCs. If you can contact all authors of the source material and they are willing to grant the BCP78 rights to the IETF Trust, you can and should remove the disclaimer. Otherwise, the disclaimer is needed and you can ignore this comment. (See the Legal Provisions document at https://trustee.ietf.org/license-info for more information.) -- The document date (February 27, 2017) is 2587 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in RFCs) == Unused Reference: 'RFC5250' is defined on line 524, but no explicit reference was found in the text == Outdated reference: A later version (-27) exists of draft-ietf-ospf-segment-routing-extensions-10 ** Downref: Normative reference to an Informational RFC: RFC 5714 Summary: 1 error (**), 0 flaws (~~), 4 warnings (==), 1 comment (--). Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 2 Network Working Group P. Psenak 3 Internet-Draft A. Lindem 4 Intended status: Standards Track L. Ginsberg 5 Expires: August 31, 2017 Cisco Systems 6 W. Henderickx 7 Nokia 8 J. Tantsura 9 Individual 10 H. Gredler 11 RtBrick Inc. 12 February 27, 2017 14 OSPFv2 Link Traffic Engineering (TE) Attribute Reuse 15 draft-ppsenak-ospf-te-link-attr-reuse-04.txt 17 Abstract 19 Various link attributes have been defined in OSPFv2 in the context of 20 the MPLS Traffic Engineering (TE) and GMPLS. Many of these link 21 attributes can be used for purposes other than MPLS Traffic 22 Engineering or GMPLS. This documents defines how to distribute such 23 attributes in OSPFv2 for applications other than MPLS Traffic 24 Engineering or GMPLS purposes. 26 Status of This Memo 28 This Internet-Draft is submitted 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). Note that other groups may also distribute 33 working documents as Internet-Drafts. The list of current Internet- 34 Drafts is at http://datatracker.ietf.org/drafts/current/. 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 This Internet-Draft will expire on August 31, 2017. 43 Copyright Notice 45 Copyright (c) 2017 IETF Trust and the persons identified as the 46 document authors. All rights reserved. 48 This document is subject to BCP 78 and the IETF Trust's Legal 49 Provisions Relating to IETF Documents 50 (http://trustee.ietf.org/license-info) in effect on the date of 51 publication of this document. Please review these documents 52 carefully, as they describe your rights and restrictions with respect 53 to this document. Code Components extracted from this document must 54 include Simplified BSD License text as described in Section 4.e of 55 the Trust Legal Provisions and are provided without warranty as 56 described in the Simplified BSD License. 58 This document may contain material from IETF Documents or IETF 59 Contributions published or made publicly available before November 60 10, 2008. The person(s) controlling the copyright in some of this 61 material may not have granted the IETF Trust the right to allow 62 modifications of such material outside the IETF Standards Process. 63 Without obtaining an adequate license from the person(s) controlling 64 the copyright in such materials, this document may not be modified 65 outside the IETF Standards Process, and derivative works of it may 66 not be created outside the IETF Standards Process, except to format 67 it for publication as an RFC or to translate it into languages other 68 than English. 70 Table of Contents 72 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3 73 1.1. Requirements notation . . . . . . . . . . . . . . . . . . 3 74 2. Link attributes examples . . . . . . . . . . . . . . . . . . 3 75 3. Advertising Link Attributes . . . . . . . . . . . . . . . . . 4 76 3.1. TE Opaque LSA . . . . . . . . . . . . . . . . . . . . . . 4 77 3.2. Extended Link Opaque LSA . . . . . . . . . . . . . . . . 4 78 3.3. Selected Approach . . . . . . . . . . . . . . . . . . . . 5 79 4. Reused TE link attributes . . . . . . . . . . . . . . . . . . 5 80 4.1. Remote interface IP address . . . . . . . . . . . . . . . 5 81 4.2. Link Local/Remote Identifiers . . . . . . . . . . . . . . 6 82 4.3. Shared Risk Link Group (SRLG) . . . . . . . . . . . . . . 6 83 4.4. Extended Metrics . . . . . . . . . . . . . . . . . . . . 6 84 5. Advertisement of Application Specific Values . . . . . . . . 7 85 6. Backward Compatibility . . . . . . . . . . . . . . . . . . . 10 86 7. Security Considerations . . . . . . . . . . . . . . . . . . . 10 87 8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 10 88 9. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 11 89 10. References . . . . . . . . . . . . . . . . . . . . . . . . . 11 90 10.1. Normative References . . . . . . . . . . . . . . . . . . 11 91 10.2. Informative References . . . . . . . . . . . . . . . . . 12 92 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 13 94 1. Introduction 96 Various link attributes have been defined in OSPFv2 [RFC2328] in the 97 context of the MPLS traffic engineering and GMPLS. All these 98 attributes are distributed by OSPFv2 as sub-TLVs of the Link-TLV 99 advertised in the OSPFv2 TE Opaque LSA [RFC3630]. 101 Many of these link attributes are useful outside of the traditional 102 MPLS Traffic Engineering or GMPLS. This brings its own set of 103 problems, in particular how to distribute these link attributes in 104 OSPFv2 when MPLS TE or GMPLS are not deployed or are deployed in 105 parallel with other applications that use these link attributes. 107 1.1. Requirements notation 109 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 110 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this 111 document are to be interpreted as described in [RFC2119]. 113 2. Link attributes examples 115 This section lists some of the link attributes originally defined for 116 MPLS Traffic Engineering that can be used for other purposes in 117 OSPFv2. The list doesn't necessarily contain all the required 118 attributes. 120 1. Remote Interface IP address [RFC3630] - OSPFv2 currently cannot 121 distinguish between parallel links between two OSPFv2 routers. 122 As a result, the two-way connectivity check performed during SPF 123 may succeed when the two routers disagree on which of the links 124 to use for data traffic. 126 2. Link Local/Remote Identifiers - [RFC4203] - Used for the two-way 127 connectivity check for parallel unnumbered links. Also used for 128 identifying adjacencies for unnumbered links in Segment Routing 129 traffic engineering. 131 3. Shared Risk Link Group (SRLG) [RFC4203] - In IPFRR, the SRLG is 132 used to compute diverse backup paths [RFC5714]. 134 4. Unidirectional Link Delay/Loss Metrics [RFC7471] - Could be used 135 for the shortest path first (SPF) computation using alternate 136 metrics within an OSPF area. 138 3. Advertising Link Attributes 140 This section outlines possible approaches for advertising link 141 attributes originally defined for MPLS Traffic Engineering purposes 142 or GMPLS when they are used for other applications. 144 3.1. TE Opaque LSA 146 One approach for advertising link attributes is to continue to use TE 147 Opaque LSA ([RFC3630]). There are several problems with this 148 approach: 150 1. Whenever the link is advertised in a TE Opaque LSA, the link 151 becomes a part of the TE topology, which may not match IP routed 152 topology. By making the link part of the TE topology, remote 153 nodes may mistakenly believe that the link is available for MPLS 154 TE or GMPLS, when, in fact, MPLS is not enabled on the link. 156 2. The TE Opaque LSA carries link attributes that are not used or 157 required by MPLS TE or GMPLS. There is no mechanism in a TE 158 Opaque LSA to indicate which of the link attributes are passed to 159 MPLS TE application and which are used by other applications 160 including OSPFv2 itself. 162 3. Link attributes used for non-TE purposes are partitioned across 163 multiple LSAs - the TE Opaque LSA and the Extended Link Opaque 164 LSA. This partitioning will require implementations to lookup 165 multiple LSAs to extract link attributes for a single link, 166 bringing needless complexity to OSPFv2 implementations. 168 The advantage of this approach is that there is no additional 169 standardization requirement to advertise the TE/GMPL attributes for 170 other applications. Additionally, link attributes are only 171 advertised once when both OSPF TE and other applications are deployed 172 on the same link. This is not expected to be a common deployment 173 scenario. 175 3.2. Extended Link Opaque LSA 177 An alternative approach for advertising link attributes is to use 178 Extended Link Opaque LSAs as defined in [RFC7684]. This LSA was 179 defined as a generic container for distribution of the extended link 180 attributes. There are several advantages in using Extended Link LSA: 182 1. Advertisement of the link attributes does not make the link part 183 of the TE topology. It avoids any conflicts and is fully 184 compatible with the [RFC3630]. 186 2. The TE Opaque LSA remains truly opaque to OSPFv2 as originally 187 defined in [RFC3630]. Its content is not inspected by OSPFv2 and 188 OSPFv2 acts as a pure transport. 190 3. There is clear distinction between link attributes used by TE and 191 link attributes used by other OSPFv2 applications. 193 4. All link attributes that are used by OSPFv2 applications are 194 advertised in a single LSA, the Extended Link Opaque LSA. 196 The disadvantage of this approach is that in rare cases, the same 197 link attribute is advertised in both the TE Opaque and Extended Link 198 Attribute LSAs. Additionally, there will be additional 199 standardization effort. However, this could also be viewed as an 200 advantage as the non-TE use cases for the TE link attributes are 201 documented and validated by the OSPF working group. 203 3.3. Selected Approach 205 It is RECOMMENDED to use the Extended Link Opaque LSA ([RFC7684] to 206 advertise any link attributes used for non-TE purposes in OSPFv2, 207 including those that have been originally defined for TE purposes. 208 TE link attributes used for TE purposes continue to use TE Opaque LSA 209 ([RFC3630]). 211 It is also RECOMMENDED to keep the format of the link attribute TLVs 212 that have been defined for TE purposes unchanged even when they are 213 used for non-TE purposes. 215 Finally, it is RECOMMENDED to allocate unique code points for link 216 attribute TLVs that have been defined for TE purposes for the OSPFv2 217 Extended Link TLV Sub-TLV Registry as defined in [RFC7684]. For each 218 reused TLV, the code point will be defined in an IETF document along 219 with the expected usecase(s). 221 4. Reused TE link attributes 223 This section defines the use case and code points for the OSPFv2 224 Extended Link TLV Sub-TLV Registry for some of the link attributes 225 that have been originally defined for TE or GMPLS purposes. 227 4.1. Remote interface IP address 229 The OSPFv2 description of an IP numbered point-to-point adjacency 230 does not include the remote IP address. As described in Section 2, 231 this makes the two-way connectivity check ambiguous in the presence 232 of the parallel point-to-point links between two OSPFv2 routers. 234 The Remote IP address of the link can also be used for Segment 235 Routing traffic engineering to identify the link in a set of parallel 236 links between two OSPFv2 routers 237 [I-D.ietf-ospf-segment-routing-extensions]. Similarly, the remote IP 238 address is useful in identifying individual parallel OSPF links 239 advertised in BGP Link-State as described in 240 [I-D.ietf-idr-ls-distribution]. 242 To advertise the Remote interface IP address in the OSPFv2 Extended 243 Link TLV, the same format of the sub-TLV as defined in section 2.5.4. 244 of [RFC3630] is used and TLV type TBD1 is used. 246 4.2. Link Local/Remote Identifiers 248 The OSPFv2 description of an IP unnumbered point-to-point adjacency 249 does not include the remote link identifier. As described in 250 Section 2, this makes the two-way connectivity check ambiguous in the 251 presence of the parallel point-to-point IP unnumbered links between 252 two OSPFv2 routers. 254 The local and remote link identifiers can also be used for Segment 255 Routing traffic engineering to identify the link in a set of parallel 256 IP unnumbered links between two OSPFv2 routers 257 [I-D.ietf-ospf-segment-routing-extensions]. Similarly, these 258 identifiers are useful in identifying individual parallel OSPF links 259 advertised in BGP Link-State as described in 260 [I-D.ietf-idr-ls-distribution]. 262 To advertise the link Local/Remote identifiers in the OSPFv2 Extended 263 Link TLV, the same format of the sub-TLV as defined in section 1.1. 264 of [RFC4203] is used and TLV type TBD2 is used. 266 4.3. Shared Risk Link Group (SRLG) 268 The SRLG of a link can be used in IPFRR to compute a backup path that 269 does not share any SRLG group with the protected link. 271 To advertise the SRLG of the link in the OSPFv2 Extended Link TLV, 272 the same format of the sub-TLV as defined in section 1.3. of 273 [RFC4203] is used and TLV type TBD3 is used. 275 4.4. Extended Metrics 277 [RFC3630] defines several link bandwidth types. [RFC7471] defines 278 extended link metrics that are based on link bandwidth, delay and 279 loss characteristics. All these can be used to compute best paths 280 within an OSPF area to satisfy requirements for bandwidth, delay 281 (nominal or worst case) or loss. 283 To advertise extended link metrics in the OSPFv2 Extended Link TLV, 284 the same format of the sub-TLVs as defined in [RFC7471] is used with 285 following TLV types: 287 TBD4 - Unidirectional Link Delay 289 TBD5 - Min/Max Unidirectional Link Delay 291 TBD6 - Unidirectional Delay Variation 293 TBD7 - Unidirectional Link Loss 295 TBD8 - Unidirectional Residual Bandwidth 297 TBD9 - Unidirectional Available Bandwidth 299 TBD10 - Unidirectional Utilized Bandwidth 301 5. Advertisement of Application Specific Values 303 Multiple applications can utilize link attributes that are flooded by 304 OSPFv2. Some examples of applications using the link attributes are 305 Segment Routing Traffic Engineering and LFA [RFC5286]. 307 In some cases the link attribute only has a single value that is 308 applicable to all applications. An example is a Remote interface IP 309 address [Section 4.1] or Link Local/Remote Identifiers [Section 4.2]. 311 In some cases the link attribute MAY have different values for 312 different applications. An example could be SRLG [Section 4.3], 313 where values used by LFA could be different then the values used by 314 Segment Routing Traffic Engineering. 316 To allow advertisement of the application specific values of the link 317 attribute, a new Extended Link Attribute sub-TLV of the Extended Link 318 TLV [RFC7471] is defined. The Extended Link Attribute sub-TLV is an 319 optional sub-TLV and can appear multiple times in the Extended Link 320 TLV. It has following format: 322 0 1 2 3 323 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 1 324 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 325 | Type | Length | 326 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 327 | Application Bit-Mask Length | Reserved | 328 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 329 | Application Bit-Mask | 330 +- -+ 331 | ... | 332 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 333 | Link Attribute sub-sub-TLVs | 334 +- -+ 335 | ... | 337 where: 339 Type: TBD11, suggested value 14 341 Length: variable 343 Application Bit-Mask Length: length of the Application Bit-Mask. 344 If the Application Bit-Mask is not present, the Application Bit- 345 Mask Length MUST be set to 0. 347 Application Bit-Mask: Optional set of bits, where each bit 348 represents a single application. The following bits are defined 349 by this document: 351 Bit-0: Segment Routing Traffic Engineering 353 Bit-1: LFA 355 Undefined bits in Application Bit-Mask MUST be transmitted as 0 and 356 MUST be ignored on receipt. Bits that are NOT transmitted MUST be 357 treated as if they are set to 0 on receipt. 359 If the link attribute advertisement is limited to be used by a 360 specific set of applications, Application Bit-Mask MUST be present 361 and application specific bit(s) MUST be set for all applications that 362 use the link attributes advertised in the Extended Link Attribute 363 sub-TLV. 365 Application Bit-Mask applies to all link attributes that support 366 application specific values and are advertised in the Extended Link 367 Attribute sub-TLV. 369 The advantage of not making the Application Bit-Mask part of the 370 attribute advertisement itself is that we can keep the format of the 371 link attributes that have been defined previously and reuse the same 372 format when advertising them in the Extended Link Attribute sub-TLV. 374 If the link attribute is advertised and there is no Application Bit- 375 Mask present in the Extended Link Attribute Sub-TLV, the link 376 attribute advertisement MAY be used by any application. If, however, 377 another advertisement of the same link attribute includes Application 378 Bit-Mask in the Extended Link Attribute sub-TLV, applications that 379 are listed in the Application Bit-Mask of such Extended Link 380 Attribute sub-TLV SHOULD use the attribute advertisement which has 381 the application specific bit set in the Application Bit-Mask. 383 If the same application is listed in the Application Bit-Mask of more 384 then one Extended Link Attribute sub-TLV, the application SHOULD use 385 the first advertisement and ignore any subsequent advertisements of 386 the same attribute. This situation SHOULD be logged as an error. 388 This document defines the set of link attributes for which the 389 Application Bit-Mask may be advertised. If the Application Bit-Mask 390 is included in the Extended Link Attribute sub-TLV that advertises 391 any link attribute(s) NOT listed below, the Application Bit-Mask MUST 392 NOT be used for such link attribute(s). It MUST be used for those 393 attribute(s) that support application specific values. Documents 394 which define new link attributes MUST state whether the new 395 attributes support application specific values. The link attributes 396 to which the Application Bit-Mask may apply are: 398 - Shared Risk Link Group 400 - Unidirectional Link Delay 402 - Min/Max Unidirectional Link Delay 404 - Unidirectional Delay Variation 406 - Unidirectional Link Loss 408 - Unidirectional Residual Bandwidth 410 - Unidirectional Available Bandwidth 412 - Unidirectional Utilized Bandwidth 414 6. Backward Compatibility 416 Link attributes may be concurrently advertised in both the TE Opaque 417 LSA [RFC3630] and the Extended Link Opaque LSA [RFC7684]. 419 In fact, there is at least one OSPF implementation that utilizes the 420 link attributes advertised in TE Opaque LSAs [RFC3630] for Non-RSVP 421 TE applications. For example, this implementation of LFA and remote 422 LFA utilizes links attributes such as Shared Risk Link Groups (SRLG) 423 [RFC4203] and Admin Group [[RFC3630]advertised in TE Opaque LSAs. 424 These applications are described in [RFC5286], [RFC7490], 425 [I-D.ietf-rtgwg-lfa-manageability] and 426 [I-D.psarkar-rtgwg-rlfa-node-protection]. 428 When an OSPF routing domain includes routers using link attributes 429 from TE Opaque LSAs for Non-RSVP TE applications such as LFA, OSPF 430 routers in that domain should continue to advertise such TE Opaque 431 LSAs. If there are also OSPF routers using the link attributes 432 described herein for Non-RSVP applications, OSPF routers in the 433 routing domain will also need to advertise these attributes in OSPF 434 Extended Link Attributes LSAs [RFC7684]. In such a deployment, the 435 advertised attributes SHOULD be the same and Non-RSVP application 436 access to link attributes is a matter of local policy. 438 7. Security Considerations 440 Implementations must assure that malformed TLV and Sub-TLV 441 permutations do not result in errors that cause hard OSPFv2 failures. 443 8. IANA Considerations 445 OSPFv2 Extended Link TLV Sub-TLVs registry [RFC7684] defines sub-TLVs 446 at any level of nesting for OSPFv2 Extended Link TLVs. This 447 specification updates OSPFv2 Extended Link TLV sub-TLVs registry with 448 the following TLV types: 450 TBD1 (4 Recommended) - Remote interface IP address 452 TBD2 (5 Recommended) - Link Local/Remote Identifiers 454 TBD3 (6 Recommended) - Shared Risk Link Group 456 TBD4 (7 Recommended) - Unidirectional Link Delay 458 TBD5 (8 Recommended) - Min/Max Unidirectional Link Delay 460 TBD6 (9 Recommended) - Unidirectional Delay Variation 461 TBD7 (10 Recommended) - Unidirectional Link Loss 463 TBD8 (11 Recommended) - Unidirectional Residual Bandwidth 465 TBD9 (12 Recommended) - Unidirectional Available Bandwidth 467 TBD10 (13 Recommended) - Unidirectional Utilized Bandwidth 469 TBD11 (14 Recommended) - Extended Link Attribute 471 This specification defines a new Link-Attribute-Applicability 472 Application Bits registry and defines following bits: 474 Bit-0 - Segment Routing Traffic Engineering 476 Bit-1 - LFA 478 9. Acknowledgments 480 Thanks to Chris Bowers for his review and comments. 482 10. References 484 10.1. Normative References 486 [I-D.ietf-idr-ls-distribution] 487 Gredler, H., Medved, J., Previdi, S., Farrel, A., and S. 488 Ray, "North-Bound Distribution of Link-State and TE 489 Information using BGP", draft-ietf-idr-ls-distribution-13 490 (work in progress), October 2015. 492 [I-D.ietf-ospf-segment-routing-extensions] 493 Psenak, P., Previdi, S., Filsfils, C., Gredler, H., 494 Shakir, R., Henderickx, W., and J. Tantsura, "OSPF 495 Extensions for Segment Routing", draft-ietf-ospf-segment- 496 routing-extensions-10 (work in progress), October 2016. 498 [I-D.ietf-rtgwg-lfa-manageability] 499 Litkowski, S., Decraene, B., Filsfils, C., Raza, K., and 500 M. Horneffer, "Operational management of Loop Free 501 Alternates", draft-ietf-rtgwg-lfa-manageability-11 (work 502 in progress), June 2015. 504 [I-D.psarkar-rtgwg-rlfa-node-protection] 505 psarkar@juniper.net, p., Gredler, H., Hegde, S., Bowers, 506 C., Litkowski, S., and H. Raghuveer, "Remote-LFA Node 507 Protection and Manageability", draft-psarkar-rtgwg-rlfa- 508 node-protection-05 (work in progress), June 2014. 510 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 511 Requirement Levels", BCP 14, RFC 2119, 512 DOI 10.17487/RFC2119, March 1997, 513 . 515 [RFC2328] Moy, J., "OSPF Version 2", STD 54, RFC 2328, 516 DOI 10.17487/RFC2328, April 1998, 517 . 519 [RFC3630] Katz, D., Kompella, K., and D. Yeung, "Traffic Engineering 520 (TE) Extensions to OSPF Version 2", RFC 3630, 521 DOI 10.17487/RFC3630, September 2003, 522 . 524 [RFC5250] Berger, L., Bryskin, I., Zinin, A., and R. Coltun, "The 525 OSPF Opaque LSA Option", RFC 5250, DOI 10.17487/RFC5250, 526 July 2008, . 528 [RFC5286] Atlas, A., Ed. and A. Zinin, Ed., "Basic Specification for 529 IP Fast Reroute: Loop-Free Alternates", RFC 5286, 530 DOI 10.17487/RFC5286, September 2008, 531 . 533 [RFC5714] Shand, M. and S. Bryant, "IP Fast Reroute Framework", 534 RFC 5714, DOI 10.17487/RFC5714, January 2010, 535 . 537 [RFC7490] Bryant, S., Filsfils, C., Previdi, S., Shand, M., and N. 538 So, "Remote Loop-Free Alternate (LFA) Fast Reroute (FRR)", 539 RFC 7490, DOI 10.17487/RFC7490, April 2015, 540 . 542 [RFC7684] Psenak, P., Gredler, H., Shakir, R., Henderickx, W., 543 Tantsura, J., and A. Lindem, "OSPFv2 Prefix/Link Attribute 544 Advertisement", RFC 7684, DOI 10.17487/RFC7684, November 545 2015, . 547 10.2. Informative References 549 [RFC4203] Kompella, K., Ed. and Y. Rekhter, Ed., "OSPF Extensions in 550 Support of Generalized Multi-Protocol Label Switching 551 (GMPLS)", RFC 4203, DOI 10.17487/RFC4203, October 2005, 552 . 554 [RFC7471] Giacalone, S., Ward, D., Drake, J., Atlas, A., and S. 555 Previdi, "OSPF Traffic Engineering (TE) Metric 556 Extensions", RFC 7471, DOI 10.17487/RFC7471, March 2015, 557 . 559 Authors' Addresses 561 Peter Psenak 562 Cisco Systems 563 Apollo Business Center 564 Mlynske nivy 43 565 Bratislava, 821 09 566 Slovakia 568 Email: ppsenak@cisco.com 570 Acee Lindem 571 Cisco Systems 572 301 Midenhall Way 573 Cary, NC 27513 574 USA 576 Email: acee@cisco.com 578 Les Ginsberg 579 Cisco Systems 580 821 Alder Drive 581 MILPITAS, CA 95035 582 USA 584 Email: ginsberg@cisco.com 586 Wim Henderickx 587 Nokia 588 Copernicuslaan 50 589 Antwerp, 2018 94089 590 Belgium 592 Email: wim.henderickx@nokia.com 594 Jeff Tantsura 595 Individual 596 USA 598 Email: jefftant.ietf@gmail.com 599 Hannes Gredler 600 RtBrick Inc. 602 Email: hannes@rtbrick.com