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Checking references for intended status: Proposed Standard ---------------------------------------------------------------------------- (See RFCs 3967 and 4897 for information about using normative references to lower-maturity documents in RFCs) == Outdated reference: A later version (-19) exists of draft-ietf-idr-bgpls-segment-routing-epe-18 == Outdated reference: A later version (-22) exists of draft-ietf-spring-segment-routing-policy-02 ** Obsolete normative reference: RFC 7752 (Obsoleted by RFC 9552) Summary: 1 error (**), 0 flaws (~~), 3 warnings (==), 1 comment (--). Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 2 Network Working Group S. Previdi 3 Internet-Draft 4 Intended status: Standards Track K. Talaulikar, Ed. 5 Expires: November 3, 2019 Cisco Systems, Inc. 6 J. Dong, Ed. 7 M. Chen 8 Huawei Technologies 9 H. Gredler 10 RtBrick Inc. 11 J. Tantsura 12 Apstra 13 May 2, 2019 15 Distribution of Traffic Engineering (TE) Policies and State using BGP-LS 16 draft-ietf-idr-te-lsp-distribution-11 18 Abstract 20 This document describes a mechanism to collect the Traffic 21 Engineering and Policy information that is locally available in a 22 node and advertise it into BGP Link State (BGP-LS) updates. Such 23 information can be used by external components for path computation, 24 re-optimization, service placement, network visualization, etc. 26 Requirements Language 28 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 29 "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and 30 "OPTIONAL" in this document are to be interpreted as described in BCP 31 14 [RFC2119] [RFC8174] when, and only when, they appear in all 32 capitals, as shown here. 34 Status of This Memo 36 This Internet-Draft is submitted in full conformance with the 37 provisions of BCP 78 and BCP 79. 39 Internet-Drafts are working documents of the Internet Engineering 40 Task Force (IETF). Note that other groups may also distribute 41 working documents as Internet-Drafts. The list of current Internet- 42 Drafts is at https://datatracker.ietf.org/drafts/current/. 44 Internet-Drafts are draft documents valid for a maximum of six months 45 and may be updated, replaced, or obsoleted by other documents at any 46 time. It is inappropriate to use Internet-Drafts as reference 47 material or to cite them other than as "work in progress." 48 This Internet-Draft will expire on November 3, 2019. 50 Copyright Notice 52 Copyright (c) 2019 IETF Trust and the persons identified as the 53 document authors. All rights reserved. 55 This document is subject to BCP 78 and the IETF Trust's Legal 56 Provisions Relating to IETF Documents 57 (https://trustee.ietf.org/license-info) in effect on the date of 58 publication of this document. Please review these documents 59 carefully, as they describe your rights and restrictions with respect 60 to this document. Code Components extracted from this document must 61 include Simplified BSD License text as described in Section 4.e of 62 the Trust Legal Provisions and are provided without warranty as 63 described in the Simplified BSD License. 65 Table of Contents 67 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3 68 2. Carrying TE Policy Information in BGP . . . . . . . . . . . . 5 69 3. TE Policy NLRI . . . . . . . . . . . . . . . . . . . . . . . 6 70 4. TE Policy Descriptors . . . . . . . . . . . . . . . . . . . . 7 71 4.1. Tunnel Identifier (Tunnel ID) . . . . . . . . . . . . . . 8 72 4.2. LSP Identifier (LSP ID) . . . . . . . . . . . . . . . . . 8 73 4.3. IPv4/IPv6 Tunnel Head-End Address . . . . . . . . . . . . 9 74 4.4. IPv4/IPv6 Tunnel Tail-End Address . . . . . . . . . . . . 9 75 4.5. SR Policy Candidate Path Descriptor . . . . . . . . . . . 10 76 4.6. Local MPLS Cross Connect . . . . . . . . . . . . . . . . 11 77 4.6.1. MPLS Cross Connect Interface . . . . . . . . . . . . 13 78 4.6.2. MPLS Cross Connect FEC . . . . . . . . . . . . . . . 14 79 5. MPLS-TE Policy State TLV . . . . . . . . . . . . . . . . . . 15 80 5.1. RSVP Objects . . . . . . . . . . . . . . . . . . . . . . 16 81 5.2. PCEP Objects . . . . . . . . . . . . . . . . . . . . . . 17 82 6. SR Policy State TLVs . . . . . . . . . . . . . . . . . . . . 18 83 6.1. SR Binding SID . . . . . . . . . . . . . . . . . . . . . 18 84 6.2. SR Candidate Path State . . . . . . . . . . . . . . . . . 20 85 6.3. SR Candidate Path Name . . . . . . . . . . . . . . . . . 22 86 6.4. SR Candidate Path Constraints . . . . . . . . . . . . . . 22 87 6.4.1. SR Affinity Constraint . . . . . . . . . . . . . . . 24 88 6.4.2. SR SRLG Constraint . . . . . . . . . . . . . . . . . 25 89 6.4.3. SR Bandwidth Constraint . . . . . . . . . . . . . . . 26 90 6.4.4. SR Disjoint Group Constraint . . . . . . . . . . . . 26 91 6.5. SR Segment List . . . . . . . . . . . . . . . . . . . . . 28 92 6.6. SR Segment . . . . . . . . . . . . . . . . . . . . . . . 31 93 6.6.1. Segment Descriptors . . . . . . . . . . . . . . . . . 32 94 6.7. SR Segment List Metric . . . . . . . . . . . . . . . . . 39 95 7. Procedures . . . . . . . . . . . . . . . . . . . . . . . . . 41 96 8. Manageability Considerations . . . . . . . . . . . . . . . . 42 97 9. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 42 98 9.1. BGP-LS NLRI-Types . . . . . . . . . . . . . . . . . . . . 42 99 9.2. BGP-LS Protocol-IDs . . . . . . . . . . . . . . . . . . . 42 100 9.3. BGP-LS TLVs . . . . . . . . . . . . . . . . . . . . . . . 43 101 9.4. BGP-LS SR Policy Protocol Origin . . . . . . . . . . . . 43 102 9.5. BGP-LS TE State Object Origin . . . . . . . . . . . . . . 44 103 9.6. BGP-LS TE State Address Family . . . . . . . . . . . . . 44 104 9.7. BGP-LS SR Segment Descriptors . . . . . . . . . . . . . . 45 105 9.8. BGP-LS Metric Type . . . . . . . . . . . . . . . . . . . 45 106 10. Security Considerations . . . . . . . . . . . . . . . . . . . 46 107 11. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 46 108 12. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 46 109 13. References . . . . . . . . . . . . . . . . . . . . . . . . . 46 110 13.1. Normative References . . . . . . . . . . . . . . . . . . 46 111 13.2. Informative References . . . . . . . . . . . . . . . . . 48 112 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 49 114 1. Introduction 116 In many network environments, traffic engineering (TE) policies are 117 instantiated into various forms: 119 o MPLS Traffic Engineering Label Switched Paths (TE-LSPs). 121 o IP based tunnels (IP in IP, GRE, etc). 123 o Segment Routing (SR) Policies as defined in 124 [I-D.ietf-spring-segment-routing-policy] 126 o Local MPLS cross-connect configuration 128 All this information can be grouped into the same term: TE Policies. 129 In the rest of this document we refer to TE Policies as the set of 130 information related to the various instantiation of polices: MPLS TE 131 LSPs, IP tunnels (IPv4 or IPv6), SR Policies, etc. 133 TE Polices are generally instantiated at the head-end and are based 134 on either local configuration or controller based programming of the 135 node using various APIs and protocols, e.g., PCEP or BGP. 137 In many network environments, the configuration and state of each TE 138 Policy that is available in the network is required by a controller 139 which allows the network operator to optimize several functions and 140 operations through the use of a controller aware of both topology and 141 state information. 143 One example of a controller is the stateful Path Computation Element 144 (PCE) [RFC8231], which could provide benefits in path reoptimization. 145 While some extensions are proposed in Path Computation Element 146 Communication Protocol (PCEP) for the Path Computation Clients (PCCs) 147 to report the LSP states to the PCE, this mechanism may not be 148 applicable in a management-based PCE architecture as specified in 149 section 5.5 of [RFC4655]. As illustrated in the figure below, the 150 PCC is not an LSR in the routing domain, thus the head-end nodes of 151 the TE-LSPs may not implement the PCEP protocol. In this case a 152 general mechanism to collect the TE-LSP states from the ingress LERs 153 is needed. This document proposes an TE Policy state collection 154 mechanism complementary to the mechanism defined in [RFC8231]. 156 ----------- 157 | ----- | 158 Service | | TED |<-+-----------> 159 Request | ----- | TED synchronization 160 | | | | mechanism (for example, 161 v | | | routing protocol) 162 ------------- Request/ | v | 163 | | Response| ----- | 164 | NMS |<--------+> | PCE | | 165 | | | ----- | 166 ------------- ----------- 167 Service | 168 Request | 169 v 170 ---------- Signaling ---------- 171 | Head-End | Protocol | Adjacent | 172 | Node |<---------->| Node | 173 ---------- ---------- 175 Figure 1. Management-Based PCE Usage 177 In networks with composite PCE nodes as specified in section 5.1 of 178 [RFC4655], PCE is implemented on several routers in the network, and 179 the PCCs in the network can use the mechanism described in [RFC8231] 180 to report the TE Policy information to the PCE nodes. An external 181 component may also need to collect the TE Policy information from all 182 the PCEs in the network to obtain a global view of the LSP state in 183 the network. 185 In multi-area or multi-AS scenarios, each area or AS can have a child 186 PCE to collect the TE Policies in its own domain, in addition, a 187 parent PCE needs to collect TE Policy information from multiple child 188 PCEs to obtain a global view of LSPs inside and across the domains 189 involved. 191 In another network scenario, a centralized controller is used for 192 service placement. Obtaining the TE Policy state information is 193 quite important for making appropriate service placement decisions 194 with the purpose to both meet the application's requirements and 195 utilize network resources efficiently. 197 The Network Management System (NMS) may need to provide global 198 visibility of the TE Policies in the network as part of the network 199 visualization function. 201 BGP has been extended to distribute link-state and traffic 202 engineering information to external components [RFC7752]. Using the 203 same protocol to collect Traffic Engineering Policy and state 204 information is desirable for these external components since this 205 avoids introducing multiple protocols for network information 206 collection. This document describes a mechanism to distribute 207 traffic engineering policy information (MPLS, SR, IPv4 and IPv6) to 208 external components using BGP-LS. 210 2. Carrying TE Policy Information in BGP 212 TE Policy information is advertised in BGP UPDATE messages using the 213 MP_REACH_NLRI and MP_UNREACH_NLRI attributes [RFC4760]. The "Link- 214 State NLRI" defined in [RFC7752] is extended to carry the TE Policy 215 information. BGP speakers that wish to exchange TE Policy 216 information MUST use the BGP Multiprotocol Extensions Capability Code 217 (1) to advertise the corresponding (AFI, SAFI) pair, as specified in 218 [RFC4760]. New TLVs carried in the Link_State Attribute defined in 219 [RFC7752] are also defined in order to carry the attributes of a TE 220 Policy in the subsequent sections. 222 The format of "Link-State NLRI" is defined in [RFC7752] as follows: 224 0 1 2 3 225 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 1 226 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 227 | NLRI Type | Total NLRI Length | 228 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 229 | | 230 // Link-State NLRI (variable) // 231 | | 232 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 234 A new "NLRI Type" is defined for TE Policy Information as following: 236 o NLRI Type: TE Policy NLRI (value TBD see IANA Considerations 237 Section 9.1). 239 The format of this new NLRI type is defined in Section 3 below. 241 3. TE Policy NLRI 243 This document defines the new TE Policy NLRI-Type and its format as 244 shown in the following figure: 246 0 1 2 3 247 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 1 248 +-+-+-+-+-+-+-+-+ 249 | Protocol-ID | 250 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 251 | Identifier | 252 | (64 bits) | 253 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 254 // Headend (Node Descriptors) // 255 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 256 // TE Policy Descriptors (variable) // 257 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 259 where: 261 o Protocol-ID field specifies the component that owns the TE Policy 262 state in the advertising node. The following new Protocol-IDs are 263 defined (values TBD see IANA Considerations Section 9.2) and apply 264 to the TE Policy NLRI: 266 +-------------+----------------------------------+ 267 | Protocol-ID | NLRI information source protocol | 268 +-------------+----------------------------------+ 269 | TBD | RSVP-TE | 270 | TBD | Segment Routing | 271 +-------------+----------------------------------+ 273 o "Identifier" is an 8 octet value as defined in [RFC7752]. 275 o "Headend" consists of a Local Node Descriptor (TLV 256) as defined 276 in [RFC7752]. 278 o "TE Policy Descriptors" consists of one or more of the TLVs listed 279 as below: (values TBD see IANA Considerations Section 9.3): 281 +-----------+----------------------------------+ 282 | Codepoint | Descriptor TLVs | 283 +-----------+----------------------------------+ 284 | TBD | Tunnel ID | 285 | TBD | LSP ID | 286 | TBD | IPv4/6 Tunnel Head-end address | 287 | TBD | IPv4/6 Tunnel Tail-end address | 288 | TBD | SR Policy Candidate Path | 289 | TBD | Local MPLS Cross Connect | 290 +-----------+----------------------------------+ 292 The Local Node Descriptor TLV MUST include the following Node 293 Descriptor TLVs: 295 o BGP Router-ID (TLV 516) [I-D.ietf-idr-bgpls-segment-routing-epe], 296 which contains a valid BGP Identifier of the local node. 298 o Autonomous System Number (TLV 512) [RFC7752], which contains the 299 ASN or AS Confederation Identifier (ASN) [RFC5065], if 300 confederations are used, of the local node. 302 The Local Node Descriptor TLV SHOULD include the following Node 303 Descriptor TLVs: 305 o IPv4 Router-ID of Local Node (TLV 1028) [RFC7752], which contains 306 the IPv4 TE Router-ID of the local node when one is provisioned. 308 o IPv6 Router-ID of Local Node (TLV 1029) [RFC7752], which contains 309 the IPv6 TE Router-ID of the local node when one is provisioned. 311 The Local Node Descriptor TLV MAY include the following Node 312 Descriptor TLVs: 314 o Member-ASN (TLV 517) [I-D.ietf-idr-bgpls-segment-routing-epe], 315 which contains the ASN of the confederation member (i.e. Member- 316 AS Number), if BGP confederations are used, of the local node. 318 o Node Descriptors as defined in [RFC7752]. 320 4. TE Policy Descriptors 322 This sections defines the TE Policy Descriptors TLVs which are used 323 to describe the TE Policy being advertised by using the new BGP-LS TE 324 Policy NLRI type defined in Section 3. 326 4.1. Tunnel Identifier (Tunnel ID) 328 The Tunnel Identifier TLV contains the Tunnel ID defined in [RFC3209] 329 and is used for RSVP-TE protocol TE Policies. It has the following 330 format: 332 0 1 2 3 333 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 1 334 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 335 | Type | Length | 336 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 337 | Tunnel ID | 338 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 340 where: 342 o Type: TBD (see IANA Considerations Section 9.3) 344 o Length: 2 octets. 346 o Tunnel ID: 2 octets as defined in [RFC3209]. 348 4.2. LSP Identifier (LSP ID) 350 The LSP Identifier TLV contains the LSP ID defined in [RFC3209] and 351 is used for RSVP-TE protocol TE Policies. It has the following 352 format: 354 0 1 2 3 355 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 1 356 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 357 | Type | Length | 358 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 359 | LSP ID | 360 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 362 where: 364 o Type: TBD (see IANA Considerations Section 9.3) 366 o Length: 2 octets. 368 o LSP ID: 2 octets as defined in [RFC3209]. 370 4.3. IPv4/IPv6 Tunnel Head-End Address 372 The IPv4/IPv6 Tunnel Head-End Address TLV contains the Tunnel Head- 373 End Address defined in [RFC3209] and is used for RSVP-TE protocol TE 374 Policies. It has following format: 376 0 1 2 3 377 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 1 378 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 379 | Type | Length | 380 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 381 // IPv4/IPv6 Tunnel Head-End Address (variable) // 382 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 384 where: 386 o Type: TBD (see IANA Considerations Section 9.3) 388 o Length: 4 or 16 octets. 390 When the IPv4/IPv6 Tunnel Head-end Address TLV contains an IPv4 391 address, its length is 4 (octets). 393 When the IPv4/IPv6 Tunnel Head-end Address TLV contains an IPv6 394 address, its length is 16 (octets). 396 4.4. IPv4/IPv6 Tunnel Tail-End Address 398 The IPv4/IPv6 Tunnel Tail-End Address TLV contains the Tunnel Tail- 399 End Address defined in [RFC3209] and is used for RSVP-TE protocol TE 400 Policies. It has following format: 402 0 1 2 3 403 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 1 404 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 405 | Type | Length | 406 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 407 // IPv4/IPv6 Tunnel Tail-End Address (variable) // 408 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 410 where: 412 o Type: TBD (see IANA Considerations Section 9.3) 414 o Length: 4 or 16 octets. 416 When the IPv4/IPv6 Tunnel Tail-end Address TLV contains an IPv4 417 address, its length is 4 (octets). 419 When the IPv4/IPv6 Tunnel Tail-end Address TLV contains an IPv6 420 address, its length is 16 (octets). 422 4.5. SR Policy Candidate Path Descriptor 424 The SR Policy Candidate Path Descriptor TLV identifies a Segment 425 Routing Policy candidate path (CP) as defined in 426 [I-D.ietf-spring-segment-routing-policy] and has the following 427 format: 429 0 1 2 3 430 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 1 431 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 432 | Type | Length | 433 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 434 |Protocol-origin| Flags | RESERVED | 435 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 436 | Endpoint (4 or 16 octets) // 437 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 438 | Policy Color (4 octets) | 439 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 440 | Originator AS Number (4 octets) | 441 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 442 | Originator Address (4 or 16 octets) // 443 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 444 | Discriminator (4 octets) | 445 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 447 where: 449 o Type: TBD (see IANA Considerations Section 9.3) 451 o Length: variable (valid values are 24, 36 or 48 octets) 453 o Protocol-Origin : 1 octet field which identifies the protocol or 454 component which is responsible for the instantiation of this path. 455 Following protocol-origin codepoints are defined in this document. 457 +------------+---------------------------------------------------------+ 458 | Code Point | Protocol Origin | 459 +------------+---------------------------------------------------------+ 460 | 1 | PCEP | 461 | 2 | BGP SR Policy | 462 | 3 | Local (via CLI, Yang model through NETCONF, gRPC, etc.) | 463 +------------+---------------------------------------------------------+ 464 o Flags: 1 octet field with following bit positions defined. Other 465 bits SHOULD be cleared by originator and MUST be ignored by 466 receiver. 468 0 1 2 3 4 5 6 7 469 +-+-+-+-+-+-+-+-+ 470 |E|O| | 471 +-+-+-+-+-+-+-+-+ 473 where: 475 * E-Flag : Indicates the encoding of endpoint as IPv6 address 476 when set and IPv4 address when clear 478 * O-Flag : Indicates the encoding of originator address as IPv6 479 address when set and IPv4 address when clear 481 o Reserved : 2 octets which SHOULD be set to 0 by originator and 482 MUST be ignored by receiver. 484 o Endpoint : 4 or 16 octets (as indicated by the flags) containing 485 the address of the endpoint of the SR Policy 487 o Color : 4 octets that indicates the color of the SR Policy 489 o Originator ASN : 4 octets to carry the 4 byte encoding of the ASN 490 of the originator. Refer [I-D.ietf-spring-segment-routing-policy] 491 Sec 2.4 for details. 493 o Originator Address : 4 or 16 octets (as indicated by the flags) to 494 carry the address of the originator. Refer 495 [I-D.ietf-spring-segment-routing-policy] Sec 2.4 for details. 497 o Discriminator : 4 octets to carry the discrimator of the path. 498 Refer [I-D.ietf-spring-segment-routing-policy] Sec 2.5 for 499 details. 501 4.6. Local MPLS Cross Connect 503 The Local MPLS Cross Connect TLV identifies a local MPLS state in the 504 form of incoming label and interface followed by an outgoing label 505 and interface. Outgoing interface may appear multiple times (for 506 multicast states). It is used with Protocol ID set to "Static 507 Configuration" value 5 as defined in [RFC7752]. 509 The Local MPLS Cross Connect TLV has the following format: 511 0 1 2 3 512 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 1 513 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 514 | Type | Length | 515 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 516 | Incoming label (4 octets) | 517 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 518 | Outgoing label (4 octets) | 519 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 520 // Sub-TLVs (variable) // 521 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 523 where: 525 o Type: TBD (see IANA Considerations Section 9.3) 527 o Length: variable. 529 o Incoming and Outgoing labels: 4 octets each. 531 o Sub-TLVs: following Sub-TLVs are defined: 533 * Interface Sub-TLV 535 * Forwarding Equivalent Class (FEC) 537 The Local MPLS Cross Connect TLV: 539 MUST have an incoming label. 541 MUST have an outgoing label. 543 MAY contain an Interface Sub-TLV having the I-flag set. 545 MUST contain at least one Interface Sub-TLV having the I-flag 546 unset. 548 MAY contain multiple Interface Sub-TLV having the I-flag unset. 549 This is the case of a multicast MPLS cross connect. 551 MAY contain a FEC Sub-TLV. 553 The following sub-TLVs are defined for the Local MPLS Cross Connect 554 TLV (values TBD see IANA Considerations Section 9.3): 556 +-----------+----------------------------------+ 557 | Codepoint | Descriptor TLV | 558 +-----------+----------------------------------+ 559 | TBD | MPLS Cross Connect Interface | 560 | TBD | MPLS Cross Connect FEC | 561 +-----------+----------------------------------+ 563 These are defined in the following sub-sections. 565 4.6.1. MPLS Cross Connect Interface 567 The MPLS Cross Connect Interface sub-TLV is optional and contains the 568 identifier of the interface (incoming or outgoing) in the form of an 569 IPv4 address or an IPv6 address. 571 The MPLS Cross Connect Interface sub-TLV has the following format: 573 0 1 2 3 574 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 1 575 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 576 | Type | Length | 577 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 579 +-+-+-+-+-+-+-+-+ 580 | Flags | 581 +-+-+-+-+-+-+-+-+ 583 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 584 | Local Interface Identifier (4 octets) | 585 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 586 // Interface Address (4 or 16 octets) // 587 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 589 where: 591 o Type: TBD (see IANA Considerations Section 9.3) 593 o Length: 9 or 21. 595 o Flags: 1 octet of flags defined as follows: 597 0 1 2 3 4 5 6 7 598 +-+-+-+-+-+-+-+-+ 599 |I| | 600 +-+-+-+-+-+-+-+-+ 602 where: 604 * I-Flag is the Interface flag. When set, the Interface Sub-TLV 605 describes an incoming interface. If the I-flag is not set, 606 then the Interface Sub-TLV describes an outgoing interface. 608 o Local Interface Identifier: a 4 octet identifier. 610 o Interface address: a 4 octet IPv4 address or a 16 octet IPv6 611 address. 613 4.6.2. MPLS Cross Connect FEC 615 The MPLS Cross Connect FEC sub-TLV is optional and contains the FEC 616 associated to the incoming label. 618 The MPLS Cross Connect FEC sub-TLV has the following format: 620 0 1 2 3 621 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 1 622 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 623 | Type | Length | 624 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 625 | Flags | Masklength | Prefix (variable) // 626 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 627 // Prefix (variable) // 628 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 630 where: 632 o Type: TBD (see IANA Considerations Section 9.3) 634 o Length: variable. 636 o Flags: 1 octet of flags defined as follows: 638 0 1 2 3 4 5 6 7 639 +-+-+-+-+-+-+-+-+ 640 |4| | 641 +-+-+-+-+-+-+-+-+ 643 where: 645 * 4-Flag is the IPv4 flag. When set, the FEC Sub-TLV describes 646 an IPv4 FEC. If the 4-flag is not set, then the FEC Sub-TLV 647 describes an IPv6 FEC. 649 o Mask Length: 1 octet of prefix length. 651 o Prefix: an IPv4 or IPv6 prefix whose mask length is given by the " 652 Mask Length" field padded to an octet boundary. 654 5. MPLS-TE Policy State TLV 656 A new TLV called "MPLS-TE Policy State TLV", is used to describe the 657 characteristics of the MPLS-TE Policy and it is carried in the 658 optional non-transitive BGP Attribute "LINK_STATE Attribute" defined 659 in [RFC7752]. These MPLS-TE Policy characteristics include the 660 characteristics and attributes of the policy, its dataplane, explicit 661 path, Quality of Service (QoS) parameters, route information, the 662 protection mechanisms, etc. 664 The MPLS-TE Policy State TLV has the following format: 666 0 1 2 3 667 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 1 668 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 669 | Type | Length | 670 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 671 | Object-origin | Address Family| RESERVED | 672 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 674 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 675 // MPLS-TE Policy State Objects (variable) // 676 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 678 where: 680 MPLS-TE Policy State TLV 682 o Type: TBD (see IANA Considerations Section 9.3) 684 o Length: the total length of the MPLS-TE Policy State TLV not 685 including Type and Length fields. 687 o Object-origin: identifies the component (or protocol) from which 688 the contained object originated. This allows for objects defined 689 in different components to be collected while avoiding the 690 possible codepoint collisions among these components. Following 691 object-origin codepoints are defined in this document. 693 +----------+------------------+ 694 | Code | Object | 695 | Point | Origin | 696 +----------+------------------+ 697 | 1 | RSVP-TE | 698 | 2 | PCEP | 699 | 3 | Local/Static | 700 +----------+------------------+ 702 o Address Family: describes the address family used to setup the 703 MPLS-TE policy. The following address family values are defined 704 in this document: 706 +----------+------------------+ 707 | Code | Dataplane | 708 | Point | | 709 +----------+------------------+ 710 | 1 | MPLS-IPv4 | 711 | 2 | MPLS-IPv6 | 712 +----------+------------------+ 714 o RESERVED: 16-bit field. SHOULD be set to 0 on transmission and 715 MUST be ignored on receipt. 717 o TE Policy State Objects: Rather than replicating all these objects 718 in this document, the semantics and encodings of the objects as 719 defined in RSVP-TE and PCEP are reused. 721 The state information is carried in the "MPLS-TE Policy State 722 Objects" with the following format as described in the sub-sections 723 below. 725 5.1. RSVP Objects 727 RSVP-TE objects are encoded in the "MPLS-TE Policy State Objects" 728 field of the MPLS-TE Policy State TLV and consists of MPLS TE LSP 729 objects defined in RSVP-TE [RFC3209] [RFC3473]. Rather than 730 replicating all MPLS TE LSP related objects in this document, the 731 semantics and encodings of the MPLS TE LSP objects are re-used. 732 These MPLS TE LSP objects are carried in the MPLS-TE Policy State 733 TLV. 735 When carrying RSVP-TE objects, the "Object-Origin" field is set to 736 "RSVP-TE". 738 The following RSVP-TE Objects are defined: 740 o SENDER_TSPEC and FLOW_SPEC [RFC2205] 741 o SESSION_ATTRIBUTE [RFC3209] 743 o EXPLICIT_ROUTE Object (ERO) [RFC3209] 745 o ROUTE_RECORD Object (RRO) [RFC3209] 747 o FAST_REROUTE Object [RFC4090] 749 o DETOUR Object [RFC4090] 751 o EXCLUDE_ROUTE Object (XRO) [RFC4874] 753 o SECONDARY_EXPLICIT_ROUTE Object (SERO) [RFC4873] 755 o SECONDARY_RECORD_ROUTE (SRRO) [RFC4873] 757 o LSP_ATTRIBUTES Object [RFC5420] 759 o LSP_REQUIRED_ATTRIBUTES Object [RFC5420] 761 o PROTECTION Object [RFC3473][RFC4872][RFC4873] 763 o ASSOCIATION Object [RFC4872] 765 o PRIMARY_PATH_ROUTE Object [RFC4872] 767 o ADMIN_STATUS Object [RFC3473] 769 o LABEL_REQUEST Object [RFC3209][RFC3473] 771 For the MPLS TE LSP Objects listed above, the corresponding sub- 772 objects are also applicable to this mechanism. Note that this list 773 is not exhaustive, other MPLS TE LSP objects which reflect specific 774 characteristics of the MPLS TE LSP can also be carried in the LSP 775 state TLV. 777 5.2. PCEP Objects 779 PCEP objects are encoded in the "MPLS-TE Policy State Objects" field 780 of the MPLS-TE Policy State TLV and consists of PCEP objects defined 781 in [RFC5440]. Rather than replicating all MPLS TE LSP related 782 objects in this document, the semantics and encodings of the MPLS TE 783 LSP objects are re-used. These MPLS TE LSP objects are carried in 784 the MPLS-TE Policy State TLV. 786 When carrying PCEP objects, the "Object-Origin" field is set to 787 "PCEP". 789 The following PCEP Objects are defined: 791 o METRIC Object [RFC5440] 793 o BANDWIDTH Object [RFC5440] 795 For the MPLS TE LSP Objects listed above, the corresponding sub- 796 objects are also applicable to this mechanism. Note that this list 797 is not exhaustive, other MPLS TE LSP objects which reflect specific 798 characteristics of the MPLS TE LSP can also be carried in the TE 799 Policy State TLV. 801 6. SR Policy State TLVs 803 Segment Routing Policy (SR Policy) architecture is specified in 804 [I-D.ietf-spring-segment-routing-policy]. A SR Policy can comprise 805 of one or more candidate paths (CP) of which at a given time one and 806 only one may be active (i.e. installed in forwarding and usable for 807 steering of traffic). Each CP in turn may have one or more SID-List 808 of which one or more may be active; when multiple are active then 809 traffic is load balanced over them. 811 This section defines the various TLVs which enable the headend to 812 report the state of an SR Policy, its CP(s), SID-List(s) and their 813 status. These TLVs are carried in the optional non-transitive BGP 814 Attribute "LINK_STATE Attribute" defined in [RFC7752] and enable the 815 same consistent form of reporting for SR Policy state irrespective of 816 the Protocol-Origin used to provision the policy. Detailed procedure 817 is described in Section 7 . 819 6.1. SR Binding SID 821 The SR Binding SID (BSID) is an optional TLV that provides the BSID 822 and its attributes for the SR Policy CP. The TLV MAY also optionally 823 contain the Provisioned BSID value for reporting when explicitly 824 provisioned. 826 The TLV has the following format: 828 0 1 2 3 829 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 1 830 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 831 | Type | Length | 832 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 833 | BSID Flags | RESERVED | 834 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 835 | Binding SID (4 or 16 octets) // 836 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 837 | Provisioned Binding SID (optional, 4 or 16 octets) // 838 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 840 where: 842 o Type: TBD (see IANA Considerations Section 9.3) 844 o Length: variable (valid values are 12, 16, 24 or 40 octets) 846 o BSID Flags: 2 octet field that indicates attribute and status of 847 the Binding SID (BSID) associated with this CP. The following bit 848 positions are defined and the semantics are described in detail in 849 [I-D.ietf-spring-segment-routing-policy]. Other bits SHOULD be 850 cleared by originator and MUST be ignored by receiver. 852 0 1 853 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 854 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 855 |D|B|U|S|L|F| | 856 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 858 where: 860 * D-Flag : Indicates the dataplane for the BSIDs and if they are 861 16 octet SRv6 SID when set and are 4 octet SR/MPLS label value 862 when clear. 864 * B-Flag : Indicates the allocation of the value in the BSID 865 field when set and indicates that BSID is not allocated when 866 clear. 868 * U-Flag : Indicates the provisioned BSID value is unavailable 869 when set. 871 * S-Flag : Indicates the BSID value in use is specified or 872 provisioned value when set and dynamically allocated value when 873 clear. 875 * L-Flag : Indicates the BSID value is from the Segment Routing 876 Local Block (SRLB) of the headend node when set and is from the 877 local label pool when clear 879 * F-Flag : Indicates the BSID value is one allocated from dynamic 880 range due to fallback (e.g. when specified BSID is unavailable) 881 when set. 883 o RESERVED: 2 octets. SHOULD be set to 0 by originator and MUST be 884 ignored by receiver. 886 o Binding SID: It indicates the operational or allocated BSID value 887 for the CP based on the status flags. 889 o Provisioned BSID: Optional field used to report the explicitly 890 provisioned BSID value as indicated by the S-Flag being clear. 892 The BSID fields above are 4 octet carrying the MPLS Label or 16 893 octets carrying the SRv6 SID based on the BSID D-flag. When carrying 894 the MPLS Label, as shown in the figure below, the TC, S and TTL 895 (total of 12 bits) are RESERVED and SHOULD be set to 0 by originator 896 and MUST be ignored by the receiver. 898 0 1 2 3 899 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 1 900 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 901 | Label | TC |S| TTL | 902 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 904 6.2. SR Candidate Path State 906 The SR Candidate Path (CP) State TLV provides the operational status 907 and attributes of the SR Policy at the CP level. The TLV has the 908 following format: 910 0 1 2 3 911 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 1 912 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 913 | Type | Length | 914 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 915 | Priority | RESERVED | Flags | 916 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 917 | Preference (4 octets) | 918 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 920 where: 922 o Type: TBD (see IANA Considerations Section 9.3) 924 o Length: 12 octets 926 o Priority : 1 octet value which indicates the priority of the CP. 927 Refer Section 2.12 of [I-D.ietf-spring-segment-routing-policy]. 929 o RESERVED: 1 octet. SHOULD be set to 0 by originator and MUST be 930 ignored by receiver. 932 o Flags: 2 octet field that indicates attribute and status of the 933 CP. The following bit positions are defined and the semantics are 934 described in detail in [I-D.ietf-spring-segment-routing-policy]. 935 Other bits SHOULD be cleared by originator and MUST be ignored by 936 receiver. 938 0 1 939 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 940 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 941 |S|A|B|E|V|O|D|C|I|T| | 942 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 944 where: 946 * S-Flag : Indicates the CP is in administrative shut state when 947 set 949 * A-Flag : Indicates the CP is the active path (i.e. one 950 provisioned in the forwarding plane) for the SR Policy when set 952 * B-Flag : Indicates the CP is the backup path (i.e. one 953 identified for path protection of the active path) for the SR 954 Policy when set 956 * E-Flag : Indicates that the CP has been evaluated for validity 957 (e.g. headend may evaluate CPs based on their preferences) when 958 set 960 * V-Flag : Indicates the CP has at least one valid SID-List when 961 set 963 * O-Flag : Indicates the CP was instantiated by the headend due 964 to an on-demand-nexthop trigger based on local template when 965 set. Refer Section 8.5 of 966 [I-D.ietf-spring-segment-routing-policy]. 968 * D-Flag : Indicates the CP was delegated for computation to a 969 PCE/controller when set 971 * C-Flag : Indicates the CP was provisioned by a PCE/controller 972 when set 974 * I-Flag : Indicates the CP will perform the "drop upon invalid" 975 behavior when no other active path is available for this SR 976 Policy and this path is the one with best preference amongst 977 the available CPs. Refer Section 8.2 of 978 [I-D.ietf-spring-segment-routing-policy]. 980 * T-Flag : Indicates the CP has been marked as eligible for use 981 as Transit Policy on the headend when set. Refer Section 8.3 982 of [I-D.ietf-spring-segment-routing-policy]. 984 o Preference : 4 octet value which indicates the preference of the 985 CP. Refer Section 2.7 of 986 [I-D.ietf-spring-segment-routing-policy]. 988 6.3. SR Candidate Path Name 990 The SR Candidate Path Name TLV is an optional TLV that is used to 991 carry the symbolic name associated with the candidate path. The TLV 992 has the following format: 994 0 1 2 3 995 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 1 996 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 997 | Type | Length | 998 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 999 | Candidate Path Symbolic Name (variable) // 1000 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1002 where: 1004 o Type: TBD (see IANA Considerations Section 9.3) 1006 o Length: variable 1008 o CP Name : Symbolic name for the CP. It is a string of printable 1009 ASCII characters without a NULL terminator. 1011 6.4. SR Candidate Path Constraints 1013 The SR Candidate Path Constraints TLV is an optional TLV that is used 1014 to report the constraints associated with the candidate path. The 1015 constraints are generally applied to a dynamic candidate path which 1016 is computed by the headend. The constraints may also be applied to 1017 an explicit path where the headend is expected to validate that the 1018 path expresses satisfies the specified constraints and the path is to 1019 be invalidated by the headend when the constraints are no longer met 1020 (e.g. due to topology changes). 1022 The TLV has the following format: 1024 0 1 2 3 1025 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 1026 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1027 | Type | Length | 1028 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1029 | Flags | RESERVED | 1030 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1031 | MTID | Algorithm | RESERVED | 1032 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1033 | sub-TLVs (variable) // 1034 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1036 where: 1038 o Type: TBD (see IANA Considerations Section 9.3) 1040 o Length: variable 1042 o Flags: 2 octet field that indicates the constraints that are being 1043 applied to the CP. The following bit positions are defined and 1044 the other bits SHOULD be cleared by originator and MUST be ignored 1045 by receiver. 1047 0 1 1048 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 1049 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1050 |D|P|U|A|T| | 1051 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1053 where: 1055 * D-Flag : Indicates that the CP needs to use SRv6 dataplane when 1056 set and SR/MPLS dataplane when clear 1058 * P-Flag : Indicates that the CP needs to use only protected SIDs 1059 when set 1061 * U-Flag : Indicates that the CP needs to use only unprotected 1062 SIDs when set 1064 * A-Flag : Indicates that the CP needs to use the SIDs belonging 1065 to the specified SR Algorithm only when set 1067 * T-Flag: Indicates that the CP needs to use the SIDs belonging 1068 to the specified topology only when set 1070 o RESERVED: 2 octet. SHOULD be set to 0 by originator and MUST be 1071 ignored by receiver. 1073 o MTID : Indicates the multi-topology identifier of the IGP topology 1074 that is preferred to be used when the path is setup. When the 1075 T-flag is set then the path is strictly useing the specified 1076 topology SIDs only. 1078 o Algorithm : Indicates the algorithm that is preferred to be used 1079 when the path is setup. When the A-flag is set then the path is 1080 strictly using the specified algorithm SIDs only. 1082 o RESERVED: 1 octet. SHOULD be set to 0 by originator and MUST be 1083 ignored by receiver. 1085 o sub-TLVs: optional sub-TLVs MAY be included in this TLV to 1086 describe other constraints. 1088 The following constraint sub-TLVs are defined for the SR CP 1089 Constraints TLV. 1091 6.4.1. SR Affinity Constraint 1093 The SR Affinity Constraint sub-TLV is an optional sub-TLV that is 1094 used to carry the affinity constraints [RFC2702] associated with the 1095 candidate path. The affinity is expressed in terms of Extended Admin 1096 Group (EAG) as defined in [RFC7308]. The TLV has the following 1097 format: 1099 0 1 2 3 1100 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 1101 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1102 | Type | Length | 1103 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1104 | Excl-Any-Size | Incl-Any-Size | Incl-All-Size | RESERVED | 1105 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1106 | Exclude-Any EAG (optional, variable) // 1107 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1108 | Include-Any EAG (optional, variable) // 1109 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1110 | Include-All EAG (optional, variable) // 1111 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1113 where: 1115 o Type: TBD (see IANA Considerations Section 9.3) 1117 o Length: variable, dependent on the size of the Extended Admin 1118 Group. MUST be a multiple of 4 octets. 1120 o Exclude-Any-Size : one octet to indicate the size of Exclude-Any 1121 EAG bitmask size in multiples of 4 octets. (e.g. value 0 1122 indicates the Exclude-Any EAG field is skipped, value 1 indicates 1123 that 4 octets of Exclude-Any EAG is included) 1125 o Include-Any-Size : one octet to indicate the size of Include-Any 1126 EAG bitmask size in multiples of 4 octets. (e.g. value 0 1127 indicates the Include-Any EAG field is skipped, value 1 indicates 1128 that 4 octets of Include-Any EAG is included) 1130 o Include-All-Size : one octet to indicate the size of Include-All 1131 EAG bitmask size in multiples of 4 octets. (e.g. value 0 1132 indicates the Include-All EAG field is skipped, value 1 indicates 1133 that 4 octets of Include-All EAG is included) 1135 o RESERVED: 1 octet. SHOULD be set to 0 by originator and MUST be 1136 ignored by receiver. 1138 o Exclude-Any EAG : the bitmask used to represent the affinities to 1139 be excluded from the path. 1141 o Include-Any EAG : the bitmask used to represent the affinities to 1142 be included in the path. 1144 o Include-All EAG : the bitmask used to represent the all affinities 1145 to be included in the path. 1147 6.4.2. SR SRLG Constraint 1149 The SR SRLG Constraint sub-TLV is an optional sub-TLV that is used to 1150 carry the Shared Risk Link Group (SRLG) values [RFC4202] that are to 1151 be excluded from the candidate path. The TLV has the following 1152 format: 1154 0 1 2 3 1155 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 1156 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1157 | Type | Length | 1158 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1159 | SRLG Values (variable, multiples of 4 octets) // 1160 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1162 where: 1164 o Type: TBD (see IANA Considerations Section 9.3) 1166 o Length: variable, dependent on the number of SRLGs encoded. MUST 1167 be a multiple of 4 octets. 1169 o SRLG Values : One or more SRLG values (each of 4 octets). 1171 6.4.3. SR Bandwidth Constraint 1173 The SR Bandwidth Constraint sub-TLV is an optional sub-TLV that is 1174 used to indicate the desired bandwidth availability that needs to be 1175 ensured for the candidate path. The TLV has the following format: 1177 0 1 2 3 1178 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 1179 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1180 | Type | Length | 1181 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1182 | Bandwidth | 1183 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1185 where: 1187 o Type: TBD (see IANA Considerations Section 9.3) 1189 o Length: 8 octects 1191 o Bandwidth : 4 octets which specify the desired bandwidth in unit 1192 of bytes per second in IEEE floating point format. 1194 6.4.4. SR Disjoint Group Constraint 1196 The SR Disjoint Group Constraint sub-TLV is an optional sub-TLV that 1197 is used to carry the disjointness constraint associated with the 1198 candidate path. The disjointness between two SR Policy Candidate 1199 Paths is expressed by associating them with the same disjoint group 1200 identifier and then specifying the type of disjointness required 1201 between their paths. The computation is expected to achieve the 1202 highest level of disjointness requested and when that is not possible 1203 then fallback to a lesser level progressively based on the levels 1204 indicated. 1206 The TLV has the following format: 1208 0 1 2 3 1209 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 1210 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1211 | Type | Length | 1212 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1213 | Request-Flags | Status-Flags | RESERVED | 1214 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1215 | Disjoint Group Identifier | 1216 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1218 where: 1220 o Type: TBD (see IANA Considerations Section 9.3) 1222 o Length: 12 octets 1224 o Request Flags : one octet to indicate the level of disjointness 1225 requested as specified in the form of flags. The following flags 1226 are defined and the other bits SHOULD be cleared by originator and 1227 MUST be ignored by receiver. 1229 0 1 2 3 4 5 6 7 1230 +-+-+-+-+-+-+-+-+ 1231 |S|N|L|F|I| | 1232 +-+-+-+-+-+-+-+-+ 1234 where: 1236 * S-Flag : Indicates that SRLG disjointness is requested 1238 * N-Flag : Indicates that node disjointness is requested when 1240 * L-Flag : Indicates that link disjointness is requested when 1242 * F-Flag : Indicates that the computation may fallback to a lower 1243 level of disjointness amongst the ones requested when all 1244 cannot be achieved 1246 * I-Flag : Indicates that the computation may fallback to the 1247 default best path (e.g. IGP path) in case of none of the 1248 desired disjointness can be achieved. 1250 o Status Flags : one octet to indicate the level of disjointness 1251 that has been achieved by the computation as specified in the form 1252 of flags. The following flags are defined and the other bits 1253 SHOULD be cleared by originator and MUST be ignored by receiver. 1255 0 1 2 3 4 5 6 7 1256 +-+-+-+-+-+-+-+-+ 1257 |S|N|L|F|I|X| | 1258 +-+-+-+-+-+-+-+-+ 1260 where: 1262 * S-Flag : Indicates that SRLG disjointness is achieved 1264 * N-Flag : Indicates that node disjointness is achieved 1266 * L-Flag : Indicates that link disjointness is achieved 1268 * F-Flag : Indicates that the computation has fallen back to a 1269 lower level of disjointness that requested. 1271 * I-Flag : Indicates that the computation has fallen back to the 1272 best path (e.g. IGP path) and disjointness has not been 1273 achieved 1275 * X-Flag : Indicates that the disjointness constraint could not 1276 be achieved and hence path has been invalidated 1278 o RESERVED: 2 octets. SHOULD be set to 0 by originator and MUST be 1279 ignored by receiver. 1281 o Disjointness Group Identifier : 4 octet value that is the group 1282 identifier for a set of disjoint paths 1284 6.5. SR Segment List 1286 The SR Segment List TLV is used to report the SID-List(s) of a 1287 candidate path. The TLV has following format: 1289 0 1 2 3 1290 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 1291 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1292 | Type | Length | 1293 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1294 | Flags | RESERVED | 1295 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1296 | MTID | Algorithm | RESERVED | 1297 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1298 | Weight (4 octets) | 1299 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1300 | sub-TLVs (variable) // 1301 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1303 where: 1305 o Type: TBD (see IANA Considerations Section 9.3) 1307 o Length: variable 1309 o Flags: 2 octet field that indicates attribute and status of the 1310 SID-List.The following bit positions are defined and the semantics 1311 are described in detail in 1312 [I-D.ietf-spring-segment-routing-policy]. Other bits SHOULD be 1313 cleared by originator and MUST be ignored by receiver. 1315 0 1 1316 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 1317 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1318 |D|E|C|V|R|F|A|T|M| | 1319 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1321 where: 1323 * D-Flag : Indicates the SID-List is comprised of SRv6 SIDs when 1324 set and indicates it is comprised of SR/MPLS labels when clear. 1326 * E-Flag : Indicates that SID-List is an explicit path when set 1327 and indicates dynamic path when clear. 1329 * C-Flag : Indicates that SID-List has been computed for a 1330 dynamic path when set. It is always reported as set for 1331 explicit paths. 1333 * V-Flag : Indicates the SID-List has passed verification or its 1334 verification was not required when set and failed verification 1335 when clear. 1337 * R-Flag : Indicates that the first Segment has been resolved 1338 when set and failed resolution when clear. 1340 * F-Flag : Indicates that the computation for the dynamic path 1341 failed when set and succeeded (or not required in case of 1342 explicit path) when clear 1344 * A-Flag : Indicates that all the SIDs in the SID-List belong to 1345 the specified algorithm when set. 1347 * T-Flag : Indicates that all the SIDs in the SID-List belong to 1348 the specified topology (identified by the multi-topology ID) 1349 when set. 1351 * M-Flag : Indicates that the SID-list has been removed from the 1352 forwarding plane due to fault detection by a monitoring 1353 mechanism (e.g. BFD) when set and indicates no fault detected 1354 or monitoring is not being done when clear. 1356 o RESERVED: 2 octet. SHOULD be set to 0 by originator and MUST be 1357 ignored by receiver. 1359 o MTID : 2 octet that indicates the multi-topology identifier of the 1360 IGP topology to be used when the T-flag is set. 1362 o Algorithm: 1 octet that indicates the algorithm of the SIDs used 1363 in the SID-List when the A-flag is set. 1365 o RESERVED: 1 octet. SHOULD be set to 0 by originator and MUST be 1366 ignored by receiver. 1368 o Weight: 4 octet field that indicates the weight associated with 1369 the SID-List for weighted load-balancing. Refer Section 2.2 and 1370 2.11 of [I-D.ietf-spring-segment-routing-policy]. 1372 o Sub-TLVs : variable and contains the ordered set of Segments and 1373 any other optional attributes associated with the specific SID- 1374 List. 1376 The SR Segment sub-TLV (defined in Section 6.6) MUST be included as 1377 an ordered set of sub-TLVs within the SR Segment List TLV when the 1378 SID-List is not empty. A SID-List may be empty in certain cases 1379 (e.g. for a dynamic path) where the headend has not yet performed the 1380 computation and hence not derived the segments required for the path; 1381 in such cases, the SR Segment List TLV SHOULD NOT include any SR 1382 Segment sub-TLVs. 1384 6.6. SR Segment 1386 The SR Segment sub-TLV describes a single segment in a SID-List. One 1387 or more instances of this sub-TLV in an ordered manner constitute a 1388 SID-List for a SR Policy candidate path. It is a sub-TLV of the SR 1389 Segment List TLV and has following format: 1391 0 1 2 3 1392 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 1393 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1394 | Type | Length | 1395 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1396 | Segment Type | RESERVED | Flags | 1397 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1398 | SID (4 or 16 octets) // 1399 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1400 // Segment Descriptor (variable) // 1401 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1402 // Sub-TLVs (variable) // 1403 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1405 where: 1407 o Type: TBD (see IANA Considerations Section 9.3) 1409 o Length: variable 1411 o Segment Type : 1 octet which indicates the type of segment (refer 1412 Section 6.6.1 for details) 1414 o RESERVED: 1 octet. SHOULD be set to 0 by originator and MUST be 1415 ignored by receiver. 1417 o Flags: 2 octet field that indicates attribute and status of the 1418 Segment and its SID. The following bit positions are defined and 1419 the semantics are described in detail in 1420 [I-D.ietf-spring-segment-routing-policy]. Other bits SHOULD be 1421 cleared by originator and MUST be ignored by receiver. 1423 0 1 1424 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 1425 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1426 |S|E|V|R|A| | 1427 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1429 where: 1431 * S-Flag : Indicates the presence of SID value in the SID field 1432 when set and that no value is indicated when clear. 1434 * E-Flag : Indicates the SID value is explicitly provisioned 1435 value (locally on headend or via controller/PCE) when set and 1436 is a dynamically resolved value by headend when clear 1438 * V-Flag : Indicates the SID has passed verification or did not 1439 require verification when set and failed verification when 1440 clear. 1442 * R-Flag : Indicates the SID has been resolved or did not require 1443 resolution (e.g. because it is not the first SID) when set and 1444 failed resolution when clear. 1446 * A-Flag : Indicates that the Algorithm indicated in the Segment 1447 descriptor is valid when set. When clear, it indicates that 1448 the headend is unable to determine the algorithm of the SID. 1450 o SID : 4 octet carrying the MPLS Label or 16 octets carrying the 1451 SRv6 SID based on the Segment Type. When carrying the MPLS Label, 1452 as shown in the figure below, the TC, S and TTL (total of 12 bits) 1453 are RESERVED and SHOULD be set to 0 by originator and MUST be 1454 ignored by the receiver. 1456 0 1 2 3 1457 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 1458 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1459 | Label | TC |S| TTL | 1460 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1462 o Segment Descriptor : variable size Segment descriptor based on the 1463 type of segment (refer Section 6.6.1 for details) 1465 o Sub-Sub-TLVs : variable and contains any other optional attributes 1466 associated with the specific SID-List. 1468 Currently no Sub-Sub-TLV of the SR Segment sub-TLV is defined. 1470 6.6.1. Segment Descriptors 1472 [I-D.ietf-spring-segment-routing-policy] section 4 defines multiple 1473 types of segments and their description. This section defines the 1474 encoding of the Segment Descriptors for each of those Segment types 1475 to be used in the Segment sub-TLV describes previously in 1476 Section 6.6. 1478 The following types are currently defined (suggested values, to be 1479 assigned by IANA): 1481 +-------+--------------------------------------------------------------+ 1482 | Type | Segment Description | 1483 +-------+--------------------------------------------------------------+ 1484 | 0 | Invalid | 1485 | 1 | SR-MPLS Label | 1486 | 2 | SRv6 SID as IPv6 address | 1487 | 3 | SR-MPLS Prefix SID as IPv4 Node Address | 1488 | 4 | SR-MPLS Prefix SID as IPv6 Node Global Address | 1489 | 5 | SR-MPLS Adjacency SID as IPv4 Node Address & Local | 1490 | | Interface ID | 1491 | 6 | SR-MPLS Adjacency SID as IPv4 Local & Remote Interface | 1492 | | Addresses | 1493 | 7 | SR-MPLS Adjacency SID as pair of IPv6 Global Address & | 1494 | | Interface ID for Local & Remote nodes | 1495 | 8 | SR-MPLS Adjacency SID as pair of IPv6 Global Addresses for | 1496 | | the Local & Remote Interface | 1497 | 9 | SRv6 END SID as IPv6 Node Global Address | 1498 | 10 | SRv6 END.X SID as pair of IPv6 Global Address & Interface ID | 1499 | | for Local & Remote nodes | 1500 | 11 | SRv6 END.X SID as pair of IPv6 Global Addresses for the | 1501 | | Local & Remote Interface | 1502 +-------+--------------------------------------------------------------+ 1504 6.6.1.1. Type 1: SR-MPLS Label 1506 The Segment is SR-MPLS type and is specified simply as the label. 1507 The format of its Segment Descriptor is as follows: 1509 0 1 2 3 1510 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 1511 +-+-+-+-+-+-+-+-+ 1512 | Algorithm | 1513 +-+-+-+-+-+-+-+-+ 1515 Where: 1517 o Algorithm: 1 octet value that indicates the algorithm used for 1518 picking the SID. This is valid only when the A-flag has been set 1519 in the Segment TLV. 1521 6.6.1.2. Type 2: SRv6 SID 1523 The Segment is SRv6 type and is specified simply as the SRv6 SID 1524 address. The format of its Segment Descriptor is as follows: 1526 0 1 2 3 1527 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 1528 +-+-+-+-+-+-+-+-+ 1529 | Algorithm | 1530 +-+-+-+-+-+-+-+-+ 1532 Where: 1534 o Algorithm: 1 octet value that indicates the algorithm used for 1535 picking the SID. This is valid only when the A-flag has been set 1536 in the Segment TLV. 1538 6.6.1.3. Type 3: SR-MPLS Prefix SID for IPv4 1540 The Segment is SR-MPLS Prefix SID type and is specified as an IPv4 1541 node address. The format of its Segment Descriptor is as follows: 1543 0 1 2 3 1544 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 1545 +-+-+-+-+-+-+-+-+ 1546 | Algorithm | 1547 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1548 | IPv4 Node Address (4 octets) | 1549 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1551 Where: 1553 o Algorithm: 1 octet value that indicates the algorithm used for 1554 picking the SID 1556 o IPv4 Node Address: 4 octet value which carries the IPv4 address 1557 associated with the node 1559 6.6.1.4. Type 4: SR-MPLS Prefix SID for IPv6 1561 The Segment is SR-MPLS Prefix SID type and is specified as an IPv6 1562 global address. The format of its Segment Descriptor is as follows: 1564 0 1 2 3 1565 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 1566 +-+-+-+-+-+-+-+-+ 1567 | Algorithm | 1568 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1569 | IPv6 Node Global Address (16 octets) | 1570 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1572 Where: 1574 o Algorithm: 1 octet value that indicates the algorithm used for 1575 picking the SID 1577 o IPv6 Node Global Address: 16 octet value which carries the IPv6 1578 global address associated with the node 1580 6.6.1.5. Type 5: SR-MPLS Adjacency SID for IPv4 with Interface ID 1582 The Segment is SR-MPLS Adjacency SID type and is specified as an IPv4 1583 node address along with the local interface ID on that node. The 1584 format of its Segment Descriptor is as follows: 1586 0 1 2 3 1587 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 1588 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1589 | IPv4 Node Address (4 octets) | 1590 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1591 | Local Interface ID (4 octets) | 1592 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1594 Where: 1596 o IPv4 Node Address: 4 octet value which carries the IPv4 address 1597 associated with the node 1599 o Local Interface ID : 4 octet value which carries the local 1600 interface ID of the node identified by the Node Address 1602 6.6.1.6. Type 6: SR-MPLS Adjacency SID for IPv4 with Interface Address 1604 The Segment is SR-MPLS Adjacency SID type and is specified as a pair 1605 of IPv4 local and remote addresses. The format of its Segment 1606 Descriptor is as follows: 1608 0 1 2 3 1609 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 1610 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1611 | IPv4 Local Address (4 octets) | 1612 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1613 | IPv4 Remote Address (4 octets) | 1614 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1616 Where: 1618 o IPv4 Local Address: 4 octet value which carries the local IPv4 1619 address associated with the node 1621 o IPv4 Remote Address: 4 octet value which carries the remote IPv4 1622 address associated with the node's neighbor. This is optional and 1623 MAY be set to 0 when not used (e.g. when identifying point-to- 1624 point links). 1626 6.6.1.7. Type 7: SR-MPLS Adjacency SID for IPv6 with interface ID 1628 The Segment is SR-MPLS Adjacency SID type and is specified as a pair 1629 of IPv6 global address and interface ID for local and remote nodes. 1630 The format of its Segment Descriptor is as follows: 1632 0 1 2 3 1633 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 1634 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1635 | IPv6 Local Node Global Address (16 octets) | 1636 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1637 | Local Node Interface ID (4 octets) | 1638 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1639 | IPv6 Remote Node Global Address (16 octets) | 1640 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1641 | Remote Node Interface ID (4 octets) | 1642 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1644 Where: 1646 o IPv6 Local Node Global Address: 16 octet value which carries the 1647 IPv6 global address associated with the local node 1649 o Local Node Interface ID : 4 octet value which carries the 1650 interface ID of the local node identified by the Local Node 1651 Address 1653 o IPv6 Remote Node Global Address: 16 octet value which carries the 1654 IPv6 global address associated with the remote node. This is 1655 optional and MAY be set to 0 when not used (e.g. when identifying 1656 point-to-point links). 1658 o Remote Node Interface ID : 4 octet value which carries the 1659 interface ID of the remote node identified by the Remote Node 1660 Address. This is optional and MAY be set to 0 when not used (e.g. 1661 when identifying point-to-point links). 1663 6.6.1.8. Type 8: SR-MPLS Adjacency SID for IPv6 with interface address 1665 The Segment is SR-MPLS Adjacency SID type and is specified as a pair 1666 of IPv6 Global addresses for local and remote interface addresses. 1667 The format of its Segment Descriptor is as follows: 1669 0 1 2 3 1670 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 1671 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1672 | Global IPv6 Local Interface Address (16 octets) | 1673 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1674 | Global IPv6 Remote Interface Address (16 octets) | 1675 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1677 Where: 1679 o IPv6 Local Address: 16 octet value which carries the local IPv6 1680 address associated with the node 1682 o IPv6 Remote Address: 16 octet value which carries the remote IPv6 1683 address associated with the node's neighbor 1685 6.6.1.9. Type 9: SRv6 END SID as IPv6 Node Address 1687 The Segment is SRv6 END SID type and is specified as an IPv6 global 1688 address. The format of its Segment Descriptor is as follows: 1690 0 1 2 3 1691 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 1692 +-+-+-+-+-+-+-+-+ 1693 | Algorithm | 1694 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1695 | IPv6 Node Global Address (16 octets) | 1696 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1698 Where: 1700 o Algorithm: 1 octet value that indicates the algorithm used for 1701 picking the SID 1703 o IPv6 Node Global Address: 16 octet value which carries the IPv6 1704 global address associated with the node 1706 6.6.1.10. Type 10: SRv6 END.X SID as interface ID 1708 The Segment is SRv6 END.X SID type and is specified as a pair of IPv6 1709 global address and interface ID for local and remote nodes. The 1710 format of its Segment Descriptor is as follows: 1712 0 1 2 3 1713 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 1714 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1715 | IPv6 Local Node Global Address (16 octets) | 1716 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1717 | Local Node Interface ID (4 octets) | 1718 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1719 | IPv6 Remote Node Global Address (16 octets) | 1720 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1721 | Remote Node Interface ID (4 octets) | 1722 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1724 Where: 1726 o IPv6 Local Node Global Address: 16 octet value which carries the 1727 IPv6 global address associated with the local node 1729 o Local Node Interface ID : 4 octet value which carries the 1730 interface ID of the local node identified by the Local Node 1731 Address 1733 o IPv6 Remote Node Global Address: 16 octet value which carries the 1734 IPv6 global address associated with the remote node. This is 1735 optional and MAY be set to 0 when not used (e.g. when identifying 1736 point-to-point links). 1738 o Remote Node Interface ID : 4 octet value which carries the 1739 interface ID of the remote node identified by the Remote Node 1740 Address. This is optional and MAY be set to 0 when not used (e.g. 1741 when identifying point-to-point links). 1743 6.6.1.11. Type 11: SRv6 END.X SID as interface address 1745 The Segment is SRv6 END.X SID type and is specified as a pair of IPv6 1746 Global addresses for local and remote interface addresses. The 1747 format of its Segment Descriptor is as follows: 1749 0 1 2 3 1750 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 1751 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1752 | Global IPv6 Local Interface Address (16 octets) | 1753 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1754 | Global IPv6 Remote Interface Address (16 octets) | 1755 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1757 Where: 1759 o IPv6 Local Address: 16 octet value which carries the local IPv6 1760 address associated with the node 1762 o IPv6 Remote Address: 16 octet value which carries the remote IPv6 1763 address associated with the node's neighbor 1765 6.7. SR Segment List Metric 1767 The SR Segment List Metric sub-TLV describes the metric used for 1768 computation of the SID-List. It is used to report the type of metric 1769 used in the computation of a dynamic path either on the headend or 1770 when the path computation is delegated to a PCE/controller. When the 1771 path computation is done on the headend, it is also used to report 1772 the calculated metric for the path. 1774 It is a sub-TLV of the SR Segment List TLV and has following format: 1776 0 1 2 3 1777 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 1778 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1779 | Type | Length | 1780 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1781 | Metric Type | Flags | RESERVED | 1782 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1783 | Metric Margin | 1784 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1785 | Metric Bound | 1786 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1787 | Metric Value | 1788 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1790 where: 1792 o Type: TBD (see IANA Considerations Section 9.3) 1794 o Length: variable 1795 o Metric Type : 1 octet field which identifies the type of metric 1796 used for path computation. Following metric type codepoints are 1797 defined in this document. 1799 +------------+-----------------------------------------+ 1800 | Code Point | Metric Type | 1801 +------------+-----------------------------------------+ 1802 | 0 | IGP Metric | 1803 | 1 | Min Unidirectional Link Delay [RFC7471] | 1804 | 2 | TE Metric [RFC3630] | 1805 +------------+-----------------------------------------+ 1807 o Flags: 1 octet field that indicates the validity of the metric 1808 fields and their semantics. The following bit positions are 1809 defined and the other bits SHOULD be cleared by originator and 1810 MUST be ignored by receiver. 1812 0 1 2 3 4 5 6 7 1813 +-+-+-+-+-+-+-+-+ 1814 |M|A|B|V| | 1815 +-+-+-+-+-+-+-+-+ 1817 where: 1819 * M-Flag : Indicates that the metric margin allowed for path 1820 computation is specified when set 1822 * A-Flag : Indicates that the metric margin is specified as an 1823 absolute value when set and is expressed as a percentage of the 1824 minimum metric when clear. 1826 * B-Flag : Indicates that the metric bound allowed for the path 1827 is specified when set. 1829 * V-Flag : Indicates that the metric value computed is being 1830 reported when set. 1832 o RESERVED: 2 octets. SHOULD be set to 0 by originator and MUST be 1833 ignored by receiver. 1835 o Metric Margin : 4 octets which indicate the metric margin value 1836 when M-flag is set. The metric margin is specified as either an 1837 absolute value or as a percentage of the minimum computed path 1838 metric based on the A-flag. The metric margin loosens the 1839 criteria for minimum metric path calculation up to the specified 1840 metric to accomodate for other factors such as bandwidth 1841 availability, minimal SID stack depth and maximizing of ECMP for 1842 the SR path computed. 1844 o Metric Bound : 4 octects which indicate the maximum metric value 1845 that is allowed when B-flag is set. If the computed path metric 1846 crosses the specified bound value then the path is considered as 1847 invalid. 1849 o Metric Value : 4 octets which indicate the metric value of the 1850 computed path when V-flag is set. This value is available and 1851 reported when the computation is successful and a valid path is 1852 available. 1854 7. Procedures 1856 The BGP-LS advertisements for the TE Policy NLRI are originated by 1857 the headend node for the TE Policies that are instantiated on its 1858 local node. 1860 For MPLS TE LSPs signaled via RSVP-TE, the NLRI descriptor TLVs as 1861 specified in Section 4.1, Section 4.2, Section 4.3 and Section 4.4 1862 are used. Then the TE LSP state is encoded in the BGP-LS Attribute 1863 field as MPLS-TE Policy State TLV as described in Section 5. The 1864 RSVP-TE objects that reflect the state of the LSP are included as 1865 defined in Section 5.1. When the TE LSP is setup with the help of 1866 PCEP signaling then another MPLS-TE Policy State TLV SHOULD be used 1867 to to encode the related PCEP objects corresponding to the LSP as 1868 defined in Section 5.2. 1870 For SR Policies, the NLRI descriptor TLV as specified in Section 4.5 1871 is used. An SR Policy candidate path (CP) may be instantiated on the 1872 headend node via a local configuration, PCEP or BGP SR Policy 1873 signaling and this is indicated via the SR Protocol Origin. Then the 1874 SR Policy Candidate Path's attribute and state is encoded in the BGP- 1875 LS Attribute field as SR Policy State TLVs and sub-TLVs as described 1876 in Section 6. The SR Candidate Path State TLV as defined in 1877 Section 6.2 is included to report the state of the CP. The SR BSID 1878 TLV as defined in Section 6.1 is included to report the BSID of the 1879 CP when one is either provisioned or allocated by the headend. The 1880 constraints for the SR Policy Candidate Path are reported using the 1881 SR Candidate Path Constraints TLV as described in Section 6.4.The SR 1882 Segment List TLV is included for each of the SID-List(s) associated 1883 with the CP. Each SR Segment List TLV in turn includes SR Segment 1884 sub-TLV(s) to report the segment(s) and their status. The SR Segment 1885 List Metric sub-TLV is used to report the metric values and 1886 constraints for the specific SID List. 1888 When the SR Policy CP is setup with the help of PCEP signaling then 1889 another MPLS-TE Policy State TLV MAY be used to to encode the related 1890 PCEP objects corresponding to the LSP as defined in Section 5.2 1891 specifically to report information and status that is not covered by 1892 the defined TLVs under Section 6. In the event of a conflict of 1893 information, the receiver MUST prefer the information originated via 1894 TLVs defined in Section 6 over the PCEP objects reported via the TE 1895 Policy State TLV. 1897 8. Manageability Considerations 1899 The Existing BGP operational and management procedures apply to this 1900 document. No new procedures are defined in this document. The 1901 considerations as specified in [RFC7752] apply to this document. 1903 In general, it is assumed that the TE Policy head-end nodes are 1904 responsible for the distribution of TE Policy state information, 1905 while other nodes, e.g. the nodes in the path of a policy, MAY report 1906 the TE Policy information (if available) when needed. For example, 1907 the border routers in the inter-domain case will also distribute LSP 1908 state information since the ingress node may not have the complete 1909 information for the end-to-end path. 1911 9. IANA Considerations 1913 This document requires new IANA assigned codepoints. 1915 9.1. BGP-LS NLRI-Types 1917 IANA maintains a registry called "Border Gateway Protocol - Link 1918 State (BGP-LS) Parameters" with a sub-registry called "BGP-LS NLRI- 1919 Types". 1921 The following codepoints is suggested (for early allocation by IANA): 1923 +------+----------------------------+---------------+ 1924 | Type | NLRI Type | Reference | 1925 +------+----------------------------+---------------+ 1926 | 5 | TE Policy NLRI type | this document | 1927 +------+----------------------------+---------------+ 1929 9.2. BGP-LS Protocol-IDs 1931 IANA maintains a registry called "Border Gateway Protocol - Link 1932 State (BGP-LS) Parameters" with a sub-registry called "BGP-LS 1933 Protocol-IDs". 1935 The following Protocol-ID codepoints are suggested (for early 1936 allocation by IANA): 1938 +-------------+----------------------------------+---------------+ 1939 | Protocol-ID | NLRI information source protocol | Reference | 1940 +-------------+----------------------------------+---------------+ 1941 | 8 | RSVP-TE | this document | 1942 | 9 | Segment Routing | this document | 1943 +-------------+----------------------------------+---------------+ 1945 9.3. BGP-LS TLVs 1947 IANA maintains a registry called "Border Gateway Protocol - Link 1948 State (BGP-LS) Parameters" with a sub-registry called "Node Anchor, 1949 Link Descriptor and Link Attribute TLVs". 1951 The following TLV codepoints are suggested (for early allocation by 1952 IANA): 1954 +----------+----------------------------------------+---------------+ 1955 | TLV Code | Description | Value defined | 1956 | Point | | in | 1957 +----------+----------------------------------------+---------------+ 1958 | 550 | Tunnel ID TLV | this document | 1959 | 551 | LSP ID TLV | this document | 1960 | 552 | IPv4/6 Tunnel Head-end address TLV | this document | 1961 | 553 | IPv4/6 Tunnel Tail-end address TLV | this document | 1962 | 554 | SR Policy CP Descriptor TLV | this document | 1963 | 555 | MPLS Local Cross Connect TLV | this document | 1964 | 556 | MPLS Cross Connect Interface TLV | this document | 1965 | 557 | MPLS Cross Connect FEC TLV | this document | 1966 | 1200 | MPLS-TE Policy State TLV | this document | 1967 | 1201 | SR BSID TLV | this document | 1968 | 1202 | SR CP State TLV | this document | 1969 | 1203 | SR CP Name TLV | this document | 1970 | 1204 | SR CP Constraints TLV | this document | 1971 | 1205 | SR Segment List TLV | this document | 1972 | 1206 | SR Segment sub-TLV | this document | 1973 | 1207 | SR Segment List Metric sub-TLV | this document | 1974 | 1208 | SR Affinity Constraint sub-TLV | this document | 1975 | 1209 | SR SRLG Constraint sub-TLV | this document | 1976 | 1210 | SR Bandwidth Constraint sub-TLV | this document | 1977 | 1211 | SR Disjoint Group Constraint sub-TLV | this document | 1978 +----------+----------------------------------------+---------------+ 1980 9.4. BGP-LS SR Policy Protocol Origin 1982 This document requests IANA to maintain a new sub-registry under 1983 "Border Gateway Protocol - Link State (BGP-LS) Parameters". The new 1984 registry is called "SR Policy Protocol Origin" and contains the 1985 codepoints allocated to the "Protocol Origin" field defined in 1986 Section 4.5. The registry contains the following codepoints 1987 (suggested values, to be assigned by IANA): 1989 +------------+---------------------------------------------------------+ 1990 | Code Point | Protocol Origin | 1991 +------------+---------------------------------------------------------+ 1992 | 1 | PCEP | 1993 | 2 | BGP SR Policy | 1994 | 3 | Local (via CLI, Yang model through NETCONF, gRPC, etc.) | 1995 +------------+---------------------------------------------------------+ 1997 9.5. BGP-LS TE State Object Origin 1999 This document requests IANA to maintain a new sub-registry under 2000 "Border Gateway Protocol - Link State (BGP-LS) Parameters". The new 2001 registry is called "TE State Path Origin" and contains the codepoints 2002 allocated to the "Object Origin" field defined in Section 5. The 2003 registry contains the following codepoints (suggested values, to be 2004 assigned by IANA): 2006 +----------+------------------+ 2007 | Code | Object | 2008 | Point | Origin | 2009 +----------+------------------+ 2010 | 1 | RSVP-TE | 2011 | 2 | PCEP | 2012 | 3 | Local/Static | 2013 +----------+------------------+ 2015 9.6. BGP-LS TE State Address Family 2017 This document requests IANA to maintain a new sub-registry under 2018 "Border Gateway Protocol - Link State (BGP-LS) Parameters". The new 2019 registry is called "TE State Address Family" and contains the 2020 codepoints allocated to the "Address Family" field defined in 2021 Section 5. The registry contains the following codepoints (suggested 2022 values, to be assigned by IANA): 2024 +----------+------------------+ 2025 | Code | Address | 2026 | Point | Family | 2027 +----------+------------------+ 2028 | 1 | MPLS-IPv4 | 2029 | 2 | MPLS-IPv6 | 2030 +----------+------------------+ 2032 9.7. BGP-LS SR Segment Descriptors 2034 This document requests IANA to maintain a new sub-registry under 2035 "Border Gateway Protocol - Link State (BGP-LS) Parameters". The new 2036 registry is called "SR Segment Descriptor Types" and contains the 2037 codepoints allocated to the "Segment Type" field defined in 2038 Section 6.6 and described in Section 6.6.1. The registry contains 2039 the following codepoints (suggested values, to be assigned by IANA): 2041 +-------+--------------------------------------------------------------+ 2042 | Code | Segment Description | 2043 | Point | | 2044 +-------+--------------------------------------------------------------+ 2045 | 0 | Invalid | 2046 | 1 | SR-MPLS Label | 2047 | 2 | SRv6 SID as IPv6 address | 2048 | 3 | SR-MPLS Prefix SID as IPv4 Node Address | 2049 | 4 | SR-MPLS Prefix SID as IPv6 Node Global Address | 2050 | 5 | SR-MPLS Adjacency SID as IPv4 Node Address & Local | 2051 | | Interface ID | 2052 | 6 | SR-MPLS Adjacency SID as IPv4 Local & Remote Interface | 2053 | | Addresses | 2054 | 7 | SR-MPLS Adjacency SID as pair of IPv6 Global Address & | 2055 | | Interface ID for Local & Remote nodes | 2056 | 8 | SR-MPLS Adjacency SID as pair of IPv6 Global Addresses for | 2057 | | the Local & Remote Interface | 2058 | 9 | SRv6 END SID as IPv6 Node Global Address | 2059 | 10 | SRv6 END.X SID as pair of IPv6 Global Address & Interface ID | 2060 | | for Local & Remote nodes | 2061 | 11 | SRv6 END.X SID as pair of IPv6 Global Addresses for the | 2062 | | Local & Remote Interface | 2063 +-------+--------------------------------------------------------------+ 2065 9.8. BGP-LS Metric Type 2067 This document requests IANA to maintain a new sub-registry under 2068 "Border Gateway Protocol - Link State (BGP-LS) Parameters". The new 2069 registry is called "Metric Type" and contains the codepoints 2070 allocated to the "metric type" field defined in Section 6.7. The 2071 registry contains the following codepoints (suggested values, to be 2072 assigned by IANA): 2074 +------------+-----------------------------------------+ 2075 | Code Point | Metric Type | 2076 +------------+-----------------------------------------+ 2077 | 0 | IGP Metric | 2078 | 1 | Min Unidirectional Link Delay [RFC7471] | 2079 | 2 | TE Metric [RFC3630] | 2080 +------------+-----------------------------------------+ 2082 10. Security Considerations 2084 Procedures and protocol extensions defined in this document do not 2085 affect the BGP security model. See [RFC6952] for details. 2087 11. Contributors 2089 The following people have substantially contributed to the editing of 2090 this document: 2092 Clarence Filsfils 2093 Cisco Systems 2094 Email: cfilsfil@cisco.com 2096 12. Acknowledgements 2098 The authors would like to thank Dhruv Dhody, Mohammed Abdul Aziz 2099 Khalid, Lou Berger, Acee Lindem, Siva Sivabalan, Arjun Sreekantiah, 2100 and Dhanendra Jain for their review and valuable comments. 2102 13. References 2104 13.1. Normative References 2106 [I-D.ietf-idr-bgpls-segment-routing-epe] 2107 Previdi, S., Talaulikar, K., Filsfils, C., Patel, K., Ray, 2108 S., and J. Dong, "BGP-LS extensions for Segment Routing 2109 BGP Egress Peer Engineering", draft-ietf-idr-bgpls- 2110 segment-routing-epe-18 (work in progress), March 2019. 2112 [I-D.ietf-spring-segment-routing-policy] 2113 Filsfils, C., Sivabalan, S., daniel.voyer@bell.ca, d., 2114 bogdanov@google.com, b., and P. Mattes, "Segment Routing 2115 Policy Architecture", draft-ietf-spring-segment-routing- 2116 policy-02 (work in progress), October 2018. 2118 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 2119 Requirement Levels", BCP 14, RFC 2119, 2120 DOI 10.17487/RFC2119, March 1997, 2121 . 2123 [RFC2205] Braden, R., Ed., Zhang, L., Berson, S., Herzog, S., and S. 2124 Jamin, "Resource ReSerVation Protocol (RSVP) -- Version 1 2125 Functional Specification", RFC 2205, DOI 10.17487/RFC2205, 2126 September 1997, . 2128 [RFC3209] Awduche, D., Berger, L., Gan, D., Li, T., Srinivasan, V., 2129 and G. Swallow, "RSVP-TE: Extensions to RSVP for LSP 2130 Tunnels", RFC 3209, DOI 10.17487/RFC3209, December 2001, 2131 . 2133 [RFC3473] Berger, L., Ed., "Generalized Multi-Protocol Label 2134 Switching (GMPLS) Signaling Resource ReserVation Protocol- 2135 Traffic Engineering (RSVP-TE) Extensions", RFC 3473, 2136 DOI 10.17487/RFC3473, January 2003, 2137 . 2139 [RFC4090] Pan, P., Ed., Swallow, G., Ed., and A. Atlas, Ed., "Fast 2140 Reroute Extensions to RSVP-TE for LSP Tunnels", RFC 4090, 2141 DOI 10.17487/RFC4090, May 2005, 2142 . 2144 [RFC4760] Bates, T., Chandra, R., Katz, D., and Y. Rekhter, 2145 "Multiprotocol Extensions for BGP-4", RFC 4760, 2146 DOI 10.17487/RFC4760, January 2007, 2147 . 2149 [RFC4872] Lang, J., Ed., Rekhter, Y., Ed., and D. Papadimitriou, 2150 Ed., "RSVP-TE Extensions in Support of End-to-End 2151 Generalized Multi-Protocol Label Switching (GMPLS) 2152 Recovery", RFC 4872, DOI 10.17487/RFC4872, May 2007, 2153 . 2155 [RFC4873] Berger, L., Bryskin, I., Papadimitriou, D., and A. Farrel, 2156 "GMPLS Segment Recovery", RFC 4873, DOI 10.17487/RFC4873, 2157 May 2007, . 2159 [RFC4874] Lee, CY., Farrel, A., and S. De Cnodder, "Exclude Routes - 2160 Extension to Resource ReserVation Protocol-Traffic 2161 Engineering (RSVP-TE)", RFC 4874, DOI 10.17487/RFC4874, 2162 April 2007, . 2164 [RFC5420] Farrel, A., Ed., Papadimitriou, D., Vasseur, JP., and A. 2165 Ayyangarps, "Encoding of Attributes for MPLS LSP 2166 Establishment Using Resource Reservation Protocol Traffic 2167 Engineering (RSVP-TE)", RFC 5420, DOI 10.17487/RFC5420, 2168 February 2009, . 2170 [RFC5440] Vasseur, JP., Ed. and JL. Le Roux, Ed., "Path Computation 2171 Element (PCE) Communication Protocol (PCEP)", RFC 5440, 2172 DOI 10.17487/RFC5440, March 2009, 2173 . 2175 [RFC7752] Gredler, H., Ed., Medved, J., Previdi, S., Farrel, A., and 2176 S. Ray, "North-Bound Distribution of Link-State and 2177 Traffic Engineering (TE) Information Using BGP", RFC 7752, 2178 DOI 10.17487/RFC7752, March 2016, 2179 . 2181 [RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 2182 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, 2183 May 2017, . 2185 13.2. Informative References 2187 [RFC2702] Awduche, D., Malcolm, J., Agogbua, J., O'Dell, M., and J. 2188 McManus, "Requirements for Traffic Engineering Over MPLS", 2189 RFC 2702, DOI 10.17487/RFC2702, September 1999, 2190 . 2192 [RFC3630] Katz, D., Kompella, K., and D. Yeung, "Traffic Engineering 2193 (TE) Extensions to OSPF Version 2", RFC 3630, 2194 DOI 10.17487/RFC3630, September 2003, 2195 . 2197 [RFC4202] Kompella, K., Ed. and Y. Rekhter, Ed., "Routing Extensions 2198 in Support of Generalized Multi-Protocol Label Switching 2199 (GMPLS)", RFC 4202, DOI 10.17487/RFC4202, October 2005, 2200 . 2202 [RFC4655] Farrel, A., Vasseur, J., and J. Ash, "A Path Computation 2203 Element (PCE)-Based Architecture", RFC 4655, 2204 DOI 10.17487/RFC4655, August 2006, 2205 . 2207 [RFC5065] Traina, P., McPherson, D., and J. Scudder, "Autonomous 2208 System Confederations for BGP", RFC 5065, 2209 DOI 10.17487/RFC5065, August 2007, 2210 . 2212 [RFC6952] Jethanandani, M., Patel, K., and L. Zheng, "Analysis of 2213 BGP, LDP, PCEP, and MSDP Issues According to the Keying 2214 and Authentication for Routing Protocols (KARP) Design 2215 Guide", RFC 6952, DOI 10.17487/RFC6952, May 2013, 2216 . 2218 [RFC7308] Osborne, E., "Extended Administrative Groups in MPLS 2219 Traffic Engineering (MPLS-TE)", RFC 7308, 2220 DOI 10.17487/RFC7308, July 2014, 2221 . 2223 [RFC7471] Giacalone, S., Ward, D., Drake, J., Atlas, A., and S. 2224 Previdi, "OSPF Traffic Engineering (TE) Metric 2225 Extensions", RFC 7471, DOI 10.17487/RFC7471, March 2015, 2226 . 2228 [RFC8231] Crabbe, E., Minei, I., Medved, J., and R. Varga, "Path 2229 Computation Element Communication Protocol (PCEP) 2230 Extensions for Stateful PCE", RFC 8231, 2231 DOI 10.17487/RFC8231, September 2017, 2232 . 2234 Authors' Addresses 2236 Stefano Previdi 2238 Email: stefano@previdi.net 2240 Ketan Talaulikar (editor) 2241 Cisco Systems, Inc. 2242 India 2244 Email: ketant@cisco.com 2246 Jie Dong (editor) 2247 Huawei Technologies 2248 Huawei Campus, No. 156 Beiqing Rd. 2249 Beijing 100095 2250 China 2252 Email: jie.dong@huawei.com 2253 Mach(Guoyi) Chen 2254 Huawei Technologies 2255 Huawei Campus, No. 156 Beiqing Rd. 2256 Beijing 100095 2257 China 2259 Email: mach.chen@huawei.com 2261 Hannes Gredler 2262 RtBrick Inc. 2264 Email: hannes@rtbrick.com 2266 Jeff Tantsura 2267 Apstra 2269 Email: jefftant.ietf@gmail.com