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Papadimitriou, ed. 7 Alcatel-Lucent 8 June 19, 2012 10 ASON Routing for OSPFv2 Protocols 11 draft-ietf-ccamp-rfc5787bis-04.txt 13 Status of this Memo 15 This Internet-Draft is submitted to IETF in full conformance with the 16 provisions of BCP 78 and BCP 79. 18 Internet-Drafts are working documents of the Internet Engineering 19 Task Force (IETF), its areas, and its working groups. Note that 20 other groups may also distribute working documents as 21 Internet-Drafts. 23 Internet-Drafts are draft documents valid for a maximum of six months 24 and may be updated, replaced, or obsoleted by other documents at any 25 time. 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Code Components extracted from this document must 45 include Simplified BSD License text as described in Section 4.e of 46 the Trust Legal Provisions and are provided without warranty as 47 described in the Simplified BSD License. 49 Abstract 51 The ITU-T has defined an architecture and requirements for operating 52 an Automatically Switched Optical Network (ASON). 54 The Generalized Multiprotocol Label Switching (GMPLS) protocol suite 55 is designed to provide a control plane for a range of network 56 technologies including optical networks such as time division 57 multiplexing (TDM) networks including SONET/SDH and Optical Transport 58 Networks (OTNs), and lambda switching optical networks. 60 The requirements for GMPLS routing to satisfy the requirements of 61 ASON routing, and an evaluation of existing GMPLS routing protocols 62 are provided in other documents. This document defines extensions to 63 the OSPFv2 Link State Routing Protocol to meet the requirements for 64 routing in an ASON. 66 Note that this work is scoped to the requirements and evaluation 67 expressed in RFC 4258 and RFC 4652 and the ITU-T Recommendations 68 current when those documents were written. Future extensions of 69 revisions of this work may be necessary if the ITU-T Recommendations 70 are revised or if new requirements are introduced into a revision of 71 RFC 4258. This document obsoletes RFC 5787 and updates RFC 5786. 73 Table of Contents 75 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 5 76 1.1. Conventions Used in This Document . . . . . . . . . . . . 6 77 2. Routing Areas, OSPF Areas, and Protocol Instances . . . . . . 6 78 3. Terminology and Identification . . . . . . . . . . . . . . . . 7 79 4. Reachability . . . . . . . . . . . . . . . . . . . . . . . . . 7 80 5. Link Attribute . . . . . . . . . . . . . . . . . . . . . . . . 8 81 5.1. Local Adaptation . . . . . . . . . . . . . . . . . . . . . 8 82 5.2. Bandwidth Accounting . . . . . . . . . . . . . . . . . . . 9 83 6. Routing Information Scope . . . . . . . . . . . . . . . . . . 9 84 6.1. Link Advertisement (Local and Remote TE Router ID 85 Sub-TLV) . . . . . . . . . . . . . . . . . . . . . . . . . 10 86 6.2. Reachability Advertisement (Local TE Router ID sub-TLV) . 11 87 7. Routing Information Dissemination . . . . . . . . . . . . . . 12 88 7.1 Import/Export Rules . . . . . . . . . . . . . . . . . . . . 12 89 7.2 Loop Prevention . . . . . . . . . . . . . . . . . . . . . . 12 90 7.2.1 Inter-RA Export Upward/Downward Sub-TLVs . . . . . . . 13 91 7.2.2 Inter-RA Export Upward/Downward Sub-TLV Processing . . 14 92 8. OSPFv2 Scalability . . . . . . . . . . . . . . . . . . . . . . 14 93 9. Security Considerations . . . . . . . . . . . . . . . . . . . 15 94 10. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 15 95 10.1. Sub-TLVs of the Link TLV . . . . . . . . . . . . . . . . 15 96 10.2. Sub-TLVs of the Node Attribute TLV . . . . . . . . . . . 16 97 10.3. Sub-TLVs of the Router Address TLV . . . . . . . . . . . 16 98 11. Management Considerations . . . . . . . . . . . . . . . . . 17 99 11.1. Routing Area (RA) Isolation . . . . . . . . . . . . . . . 17 100 11.2 Routing Area (RA) Topology/Configuration Changes . . . . . 17 101 12. Comparison to Requirements in RFC 4258 . . . . . . . . . . . 17 102 13. References . . . . . . . . . . . . . . . . . . . . . . . . . 23 103 13.1. Normative References . . . . . . . . . . . . . . . . . . 23 104 13.2. Informative References . . . . . . . . . . . . . . . . . 24 105 14. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 25 106 Appendix A. ASON Terminology . . . . . . . . . . . . . . . . . . 26 107 Appendix B. ASON Routing Terminology . . . . . . . . . . . . . . 27 108 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 28 110 1. Introduction 112 The Generalized Multiprotocol Label Switching (GMPLS) [RFC3945] 113 protocol suite is designed to provide a control plane for a range of 114 network technologies including optical networks such as time division 115 multiplexing (TDM) networks including SONET/SDH and Optical Transport 116 Networks (OTNs), and lambda switching optical networks. 118 The ITU-T defines the architecture of the Automatically Switched 119 Optical Network (ASON) in [G.8080]. 121 [RFC4258] describes the routing requirements for the GMPLS suite of 122 routing protocols to support the capabilities and functionality of 123 ASON control planes identified in [G.7715] and in [G.7715.1]. 125 [RFC4652] evaluates the IETF Link State routing protocols against the 126 requirements identified in [RFC4258]. Section 7.1 of [RFC4652] 127 summarizes the capabilities to be provided by OSPFv2 [RFC2328] in 128 support of ASON routing. This document describes the OSPFv2 129 specifics for ASON routing. 131 Multi-layer transport networks are constructed from multiple networks 132 of different technologies operating in a client-server relationship. 133 The ASON routing model includes the definition of routing levels that 134 provide scaling and confidentiality benefits. In multi-level 135 routing, domains called routing areas (RAs) are arranged in a 136 hierarchical relationship. Note that as described in [RFC4652], 137 there is no implied relationship between multi-layer transport 138 networks and multi-level routing. The multi-level routing mechanisms 139 described in this document work for both single-layer and multi-layer 140 networks. 142 Implementations may support a hierarchical routing topology (multi- 143 level) for multiple transport network layers and/or a hierarchical 144 routing topology for a single transport network layer. 146 This document describes the processing of the generic (technology- 147 independent) link attributes that are defined in [RFC3630], 148 [RFC4202], and [RFC4203] and that are extended in this document. As 149 described in Section 5.2, technology-specific traffic engineering 150 attributes and their processing may be defined in other documents 151 that complement this document. 153 Note that this work is scoped to the requirements and evaluation 154 expressed in [RFC4258] and [RFC4652] and the ITU-T Recommendations 155 current when those documents were written. Future extensions of 156 revisions of this work may be necessary if the ITU-T Recommendations 157 are revised or if new requirements are introduced into a revision of 159 [RFC4258]. 161 1.1. Conventions Used in This Document 163 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 164 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this 165 document are to be interpreted as described in RFC 2119 [RFC2119]. 167 The reader is assumed to be familiar with the terminology and 168 requirements developed in [RFC4258] and the evaluation outcomes 169 described in [RFC4652]. 171 General ASON terminology is provided in Appendix A. ASON routing 172 terminology is described in Appendix B. 174 2. Routing Areas, OSPF Areas, and Protocol Instances 176 An ASON routing area (RA) represents a partition of the data plane, 177 and its identifier is used within the control plane as the 178 representation of this partition. 180 RAs are hierarchically contained: a higher-level (parent) RA contains 181 lower-level (child) RAs that in turn MAY also contain RAs. 182 Thus, RAs contain RAs that recursively define successive hierarchical 183 RA levels. Routing information may be exchanged between levels of 184 the RA hierarchy, i.e., Level N+1 and N, where Level N represents the 185 RAs contained by Level N+1. The links connecting RAs may be viewed 186 as external links (inter-RA links), and the links representing 187 connectivity within an RA may be viewed as internal links (intra-RA 188 links). The external links to an RA at one level of the hierarchy 189 may be internal links in the parent RA. Intra-RA links of a child RA 190 MAY be hidden from the parent RA's view. [RFC4258] 192 An ASON RA can be mapped to an OSPF area, but the hierarchy of ASON 193 RA levels does not map to the hierarchy of OSPF areas. Instead, 194 successive hierarchical levels of RAs MUST be represented by separate 195 instances of the protocol. Thus, inter-level routing information 196 exchange (as described in Section 7) involves the export and import 197 of routing information between protocol instances. 199 An ASON RA may therefore be identified by the combination of its OSPF 200 instance identifier and its OSPF area identifier. With proper and 201 careful network-wide configuration, this can be achieved using just 202 the OSPF area identifier, and this process is RECOMMENDED in this 203 document. These concepts are discussed in Section 7. 205 A key ASON requirement is the support of multiple transport planes or 206 layers. Each transport node has associated topology (links and 207 reachability) which is used for ASON routing. 209 3. Terminology and Identification 211 This section describes the mapping of key ASON entities to OSPF 212 entities. Appendix A contains a complete glossary of ASON routing 213 terminology. 215 There are three categories of identifiers used for ASON routing 216 (G7715.1): transport plane names, control plane identifiers for 217 components, and Signaling Communications Network (SCN) addresses. 218 This section discusses the mapping between ASON routing identifiers 219 and corresponding identifiers defined for GMPLS routing, and how 220 these support the physical (or logical) separation of transport plane 221 entities and control plane components. GMPLS supports this 222 separation of identifiers and planes. 224 In the context of OSPF Traffic Engineering (TE), an ASON transport 225 node corresponds to a unique OSPF TE node. An OSPF TE node is 226 uniquely identified by the TE Router Address TLV [RFC3630]. In this 227 document, this TE Router Address is referred to as the TE Router ID, 228 which is in the ASON SCN name space. The TE Router ID 229 should not be confused with the OSPF Router ID which uniquely 230 identifies an OSPF router within an OSPF routing domain [RFC2328] and 231 is in a name space for control plane components. 233 The Router Address top-level TLV definition, processing, and 234 usage are largely unchanged from [RFC3630]. This TLV specifies a stable 235 OSPF TE node IP address, i.e., the IP address is always reachable when 236 there is IP connectivity to the associated OSPF TE node. However, in 237 the context of the OSPF ASON operation, the TE Router ID is an 238 identifier within the ASON SCN. 240 ASON defines a Routing Controller (RC) as an entity that handles 241 (abstract) information needed for routing and the routing information 242 exchange with peering RCs by operating on the Routing Database (RDB). 243 ASON defines a Protocol Controller (PC) as an entity that handles 244 protocol-specific message exchanges according to the reference point 245 over which the information is exchanged (e.g., E-NNI, I-NNI), and 246 internal exchanges with the Routing Controller (RC) [RFC4258]. In 247 this document, an OSPF router advertising ASON TE topology 248 information will perform both the functions of the RC and PC. The 249 OSPF routing domain comprises the control plane and each 250 OSPF router is uniquely identified by its OSPF Router ID [RFC2328]. 252 4. Reachability 254 In ASON, reachability refers to the set of endpoints reachable in the 255 transport plane by an associated ASON transport node. 256 Reachable entities are identified in the ASON SCN name space. 258 In order to advertise blocks of reachable 259 address prefixes, a summarization mechanism is introduced that is 260 based on the techniques described in [RFC5786]. For ASON reachability 261 advertisement, blocks of reachable address prefixes are advertised 262 together with the associated transport plane node. The transport 263 plane node is identified in OSPF TE LSAs by its TE Router ID, 264 as discussed in section 6. 266 In order to support ASON reachability advertisement, the Node 267 Attribute TLV defined in [RFC5786] is used to advertise the 268 combination of a TE Router ID and its set of associated reachable 269 address prefixes. The Node Attribute TLV can contain the following 270 sub-TLVs: 272 - TE Router ID sub-TLV: Length: 4; Defined in Section 6.2 273 - Node IPv4 Local Address sub-TLV: Length: variable; [RFC5786] 274 - Node IPv6 Local Address sub-TLV: Length: variable; [RFC5786] 276 A router may support multiple transport nodes as discussed in section 277 6, and, as a result, may be required to advertise reachability 278 separately for each transport node. As a consequence, it MUST 279 be possible for the router to originate more than one TE LSA 280 containing the Node Attribute TLV when used for ASON reachability 281 advertisement. 283 Hence, the Node Attribute TLV [RFC5786] advertisement rules are 284 relaxed. A Node Attribute TLV MAY appear in more than one TE 285 LSA originated by the RC when the RC is advertising reachability 286 information for a different transport node identified by the Local TE 287 Router Sub-TLV (refer to section 6.1). 289 5. Link Attribute 291 With the exception of local adaptation (described below), the mapping 292 of link attributes and characteristics to OSPF TE Link TLV Sub-TLVs 293 is unchanged [RFC4652]. OSPF TE Link TLV Sub-TLVs are described in 294 [RFC3630] and [RFC4203]. Advertisement of this information SHOULD be 295 supported on a per-layer basis, i.e., one TE LSA per unique switching 296 capability and bandwidth granularity combination. 298 5.1. Local Adaptation 300 Local adaptation is defined as a TE link attribute (i.e., sub-TLV) 301 that describes the cross/inter-layer relationships. 303 The Interface Switching Capability Descriptor (ISCD) TE Attribute 304 [RFC4202] identifies the ability of the TE link to support cross- 305 connection to another link within the same layer. When advertising 306 link adaptation, it also identifies the ability to use a locally 307 terminated connection that belongs to one layer as a data link for 308 another layer (adaptation capability). However, the information 309 associated with the ability to terminate connections within that 310 layer (referred to as the termination capability) is advertised with 311 the adaptation capability. 313 For instance, a link between two optical cross-connects will contain 314 at least one ISCD attribute describing the Lambda Switching Capable 315 (LSC) switching capability. Conversely, a link between an optical 316 cross-connect and an IP/MPLS Label Switching Router (LSR) will 317 contain at least two ISCD attributes, one for the description of the 318 LSC termination capability and one for the Packet Switching Capable 319 (PSC) adaptation capability. 321 In OSPFv2, the Interface Switching Capability Descriptor (ISCD) is a 322 sub-TLV (type 15) of the top-level Link TLV (type 2) [RFC4203]. The 323 adaptation and termination capabilities are advertised using two 324 separate ISCD sub-TLVs within the same top-level Link TLV. 326 An interface MAY have more than one ISCD sub-TLV, [RFC4202] and 327 [RFC4203]. Hence, the corresponding advertisements should not result 328 in any compatibility issues. 330 5.2. Bandwidth Accounting 332 GMPLS routing defines an Interface Switching Capability Descriptor 333 (ISCD) that provides, among other things, the quantities of the 334 maximum/minimum available bandwidth per priority for Label Switched 335 Path (LSPs). One or more ISCD sub-TLVs can be associated with an 336 interface, [RFC4202] and [RFC4203]. This information, combined with 337 the Unreserved Bandwidth Link TLV sub-TLV [RFC3630], provides the 338 basis for bandwidth accounting. 340 In the ASON context, additional information may be included when the 341 representation and information in the other advertised fields are not 342 sufficient for a specific technology, e.g., SDH. The definition of 343 technology-specific information elements is beyond the scope of this 344 document. Some technologies will not require additional information 345 beyond what is already defined in [RFC3630], [RFC4202], and 346 [RFC4203]. 348 6. Routing Information Scope 350 For ASON routing, the control plane component routing adjacency 351 topology (i.e., the associated Protocol Controller (PC) connectivity) 352 and the transport topology are not assumed to be congruent [RFC4258]. 353 Hence, a single OSPF router (i.e., the PC) MUST be able to advertise 354 on behalf of multiple transport layer nodes. The OSPF routers are 355 identified by OSPF Router ID and the transport nodes are identified 356 by TE Router ID. 358 The Router Address TLV [RFC3630] is used to advertise the TE Router 359 ID associated with the advertising Routing Controller (RC). TE Router IDs 360 for additional transport nodes are advertised through specification 361 of the Local TE Router Identifier in the Local and Remote TE Router 362 TE sub-TLV and the Local TE Router Identifier sub-TLV described in 363 the sections below. These Local TE Router Identifiers are typically 364 used as the local endpoints for TE Label Switched Paths (LSPs) 365 terminating on the associated transport node. 367 The use of multiple OSPF Routers to advertise TE information for the 368 same transport node is not considered a required use case and is not 369 discussed further in this document. 371 6.1. Link Advertisement (Local and Remote TE Router ID Sub-TLV) 373 When an OSPF Router advertises on behalf of multiple transport nodes, 374 the link end points cannot be automatically assigned to a single 375 transport node associated with the advertising router. In this case, 376 the local and remote transport nodes MUST be identified by TE router 377 ID to unambiguously specify the transport topology. 379 For this purpose, a new sub-TLV of the OSPFv2 TE LSA top-level Link 380 TLV is introduced that defines the Local and Remote TE Router ID. 382 The Type field of the Local and Remote TE Router ID sub-TLV is 383 assigned the value TBDx (see Section 10). The Length field takes the 384 value 8. The Value field of this sub-TLV contains 4 octets of the 385 Local TE Router Identifier followed by 4 octets of the Remote TE 386 Router Identifier. The value of the Local and Remote TE Router 387 Identifier SHOULD NOT be set to 0. 389 The format of the Local and Remote TE Router ID sub-TLV is: 391 0 1 2 3 392 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 1 393 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 394 | Type (TBDx) | Length (8) | 395 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 396 | Local TE Router Identifier | 397 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 398 | Remote TE Router Identifier | 399 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 401 This sub-TLV MUST be included as a sub-TLV of the top-level Link TLV 402 if the OSPF router is advertising on behalf of one or more transport 403 nodes having TE Router IDs different from the TE Router ID advertised 404 in the Router Address TLV. For consistency, this sub-TLV MUST be 405 included when OSPF is used for the advertisement of ASON information 406 as described herein. If it is not included in a Link TLV or a value 407 of 0 is specified for the Local or Remote TE Router Identifier, the 408 Link TLV will not be used for transport plane path computation. 409 Additionally, the condition SHOULD be logged for possible action by 410 the network operator. 412 Note: The Link ID sub-TLV identifies the other end of the link (i.e., 413 Router ID of the neighbor for point-to-point links) [RFC3630]. When 414 the Local and Remote TE Router ID Sub-TLV is present, it MUST be used 415 to identify local and remote transport node endpoints for the link 416 and the Link-ID sub-TLV MUST be ignored. In fact, when the Local 417 and Remote ID sub-TLV is specified, the Link-ID sub-TLV MAY be omitted. 418 The Local and Remote ID sub-TLV, if specified, MUST only be specified once. 419 If specified more than once, instances preceding the first will be ignored and 420 condition SHOULD be logged for possible action by the network operator. 422 6.2. Reachability Advertisement (Local TE Router ID sub-TLV) 424 When an OSPF router is advertising on behalf of multiple transport 425 nodes, the routing protocol MUST be able to associate the advertised 426 reachability information with the correct transport node. 428 For this purpose, a new sub-TLV of the OSPFv2 TE LSA top-level Node 429 Attribute TLV is introduced. This TLV associates the local prefixes 430 (see above) to a given transport node identified by TE Router ID. 432 The Type field of the Local TE Router ID sub-TLV is assigned the 433 value 5 (see Section 10). The Length field takes the value 4. The 434 Value field of this sub-TLV contains the Local TE Router Identifier 435 [RFC3630] encoded over 4 octets. 437 The format of the Local TE Router ID sub-TLV is: 439 0 1 2 3 440 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 1 441 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 442 | Type (5) | Length (4) | 443 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 444 | Local TE Router Identifier | 445 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 447 This sub-TLV MUST be included as a sub-TLV of the top-level Node 448 Attribute TLV if the OSPF router is advertising on behalf of one or 449 more transport nodes having TE Router IDs different from the TE 450 Router ID advertised in the Router Address TLV. For consistency, 451 this sub-TLV MUST be included when OSPF is used for the advertisement 452 of ASON information as described herein. If it is not included in a 453 Node Attribute TLV or a value of 0 is specified for the Local TE 454 Router Identifier, the Note Attribute TLV will not be used for 455 determining ASON SCN reachability. Additionally, the condition 456 SHOULD be logged for possible action by the network operator. 458 7. Routing Information Dissemination 460 An ASON routing area (RA) represents a partition of the data plane, 461 and its identifier is used within the control plane as the 462 representation of this partition. An RA may contain smaller RAs 463 inter-connected by links. ASON RA levels do not map directly to OSPF 464 areas. Rather, hierarchical levels of RAs are represented by separate 465 OSPF protocol instances. However, it is useful to align the RA 466 identifiers and area ID in order to facilitate isolation of RAs as 467 described in Section 11.1. 469 Routing controllers (RCs) supporting multiple RAs disseminate 470 information downward and upward in this ASON hierarchy. The vertical 471 routing information dissemination mechanisms described in this 472 section do not introduce or imply hierarchical OSPF areas. RCs 473 supporting RAs at multiple levels are structured as separate OSPF 474 instances with routing information exchange between levels described 475 by import and export rules between these instances. The functionality 476 described herein does not pertain to OSPF areas or OSPF Area Border 477 Router (ABR) functionality. 479 7.1 Import/Export Rules 481 RCs supporting RAs disseminate information upward and downward in the 482 hierarchy by importing/exporting routing information as TE LSAs. TE 483 LSAs are area-scoped opaque LSAs with opaque type 1 [RFC3630]. The 484 information that MAY be exchanged between adjacent levels includes 485 the Router Address, Link, and Node Attribute top-level TLVs. 487 The imported/exported routing information content MAY be transformed, 488 e.g., filtered or aggregated, as long as the resulting routing 489 information is consistent. In particular, when more than one RC is 490 bound to adjacent levels and both are allowed to import/export 491 routing information, it is expected that these transformations are 492 performed in a consistent manner. Definition of these policy-based 493 mechanisms are outside the scope of this document. 495 In practice, and in order to avoid scalability and processing 496 overhead, routing information imported/exported downward/upward in 497 the hierarchy is expected to include reachability information (see 498 Section 4) and, upon strict policy control, link topology 499 information. 501 7.2 Loop Prevention 503 When more than one RC is bound to an adjacent level of the ASON 504 hierarchy, and is configured to export routing information upward or 505 downward, a specific mechanism is required to avoid looping of 506 routing information. Looping is the re-advertisement of routing 507 information into an RA that had previously advertised that routing 508 information upward or downward into an upper or lower level RA in the 509 ASON hierarchy. For example, without loop prevention mechanisms, this 510 could happen when the RC advertising routing information downward in 511 the hierarchy is not the same one that advertises routing information 512 upward in the hierarchy. 514 7.2.1 Inter-RA Export Upward/Downward Sub-TLVs 516 The Inter-RA Export Sub-TLVs can be used to prevent the re- 517 advertisement of OSPF TE routing information into an RA which 518 previously advertised that information. The type value TBDz (see 519 Section 10) will indicate that the associated routing information has 520 been exported downward. The type value TBDy (see Section 10) will 521 indicate that the associated routing information has been exported 522 upward. While it is not required for routing information exported 523 downward, both Sub-TLVs will include the Routing Area (RA) ID from 524 which the routing information was exported. This RA is not 525 necessarily the RA originating the routing information but RA from 526 which the information was immediately exported. 528 These additional Sub-TLVs MAY be included in TE LSAs that include any 529 of the following top-level TLVs: 531 - Router Address top-level TLV 532 - Link top-level TLV 533 - Node Attribute top-level TLV 535 The Type field of the Inter-RA Export Upward and Inter-RA Export 536 Downward sub-TLVs are respectively assigned the values TBDy and TBDz 537 (see Section 10). The Length field in these Sub-TLVs takes the 538 value 4. The Value field in these sub-TLVs contains the associated 539 RA ID. The RA ID value must be a unique identifier for the RA within 540 the ASON routing domain. 542 The format of the Inter-RA Export Upward and Inter-RA Export Downward 543 Sub-TLVs is graphically depicted below: 545 0 1 2 3 546 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 1 547 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 548 | Upward/Downward Type | Length (4) | 549 | (TBDy/TBDz) | | 550 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 551 | Associated RA ID | 552 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 554 7.2.2 Inter-RA Export Upward/Downward Sub-TLV Processing 556 TE LSAs MAY be imported or exported downward or upward in the ASON 557 routing hierarchy. The direction and advertising RA ID are advertised 558 in an Inter-RA Export Upward/Downward Sub-TLV. They MUST be retained 559 and advertised in the receiving RA with the associated routing 560 information. 562 When exporting routing information upward in the ASON routing 563 hierarchy, any information received from a level above, i.e., tagged 564 with an Inter-RA Export Downward Sub-TLV, MUST NOT be exported 565 upward. Since an RA at level N is contained by a single RA at level 566 N+1, this is the only checking that is necessary and the associated 567 RA ID is used solely for informational purposes. 569 When exporting routing information downward in the ASON routing 570 hierarchy, any information received from a level below, i.e., tagged 571 with an Inter-RA Export Upward Sub-TLV MUST NOT be exported downward 572 if the target RA ID matches the RA ID associated with the routing 573 information. This additional checking is required for routing 574 information exported downward since a single RA at level N+1 may 575 contain multiple RAs at level N in the ASON routing hierarchy. In 576 order words, routing information MUST NOT be exported downward into 577 the RA from which it was received. 579 8. OSPFv2 Scalability 581 The extensions described herein are only applicable to ASON routing 582 domains and it is not expected that the attendant reachability (see 583 Section 4) and link information will ever be combined with global 584 Internet or Layer 3 Virtual Private Network (VPN) routing. If there 585 were ever a requirement for a given RC to participate in both domains, 586 separate OSPFv2 instances would be utilized. However, in a 587 multi-level ASON hierarchy, the potential volume of information could 588 be quite large and the recommendations in this section MUST be 589 followed by RCs implementing this specification. 591 - Routing information exchange upward/downward in the hierarchy 592 between adjacent RAs MUST, by default, be limited to reachability 593 information. In addition, several transformations such as prefix 594 aggregation are RECOMMENDED to reduce the amount of information 595 imported/exported by a given RC when such transformations will not 596 impact consistency. 598 - Routing information exchange upward/downward in the ASON hierarchy 599 involving TE attributes MUST be under strict policy control. 600 Pacing and min/max thresholds for triggered updates are strongly 601 RECOMMENDED. 603 - The number of routing levels MUST be maintained under strict policy 604 control. 606 9. Security Considerations 608 This document specifies the contents and processing of OSPFv2 TE LSAs 609 [RFC3630] and [RFC4202]. The TE LSA extensions defined in this 610 document are not used for SPF computation, and have no direct effect 611 on IP routing. Additionally, ASON routing domains are delimited by 612 the usual administrative domain boundaries. 614 Any mechanisms used for securing the exchange of normal OSPF LSAs can 615 be applied equally to all TE LSAs used in the ASON context. 616 Authentication of OSPFv2 LSA exchanges (such as OSPF cryptographic 617 authentication [RFC2328] and [RFC5709]) can be used to secure against 618 passive attacks and provide significant protection against active 619 attacks. [RFC5709] defines a mechanism for authenticating OSPFv2 620 packets by making use of the HMAC algorithm in conjunction with the 621 SHA family of cryptographic hash functions. 623 If a stronger authentication were believed to be required, then the 624 use of a full digital signature [RFC2154] would be an approach that 625 should be seriously considered. Use of full digital signatures would 626 enable precise authentication of the OSPF router originating each 627 OSPF link-state advertisement, and thereby provide much stronger 628 integrity protection for the OSPF routing domain. 630 RCs implementing export/import of ASON routing information between 631 RAs MUST also include policy control of both the maximum amount of 632 information advertised between RAs and the maximum rate at which 633 it is advertised. This is to isolate the consequences of an RC 634 being compromised to the RAs to which that subverted RC is attached. 636 10. IANA Considerations 638 This document is classified as Standards Track. It defines new sub- 639 TLVs for inclusion in OSPF TE LSAs. According to the assignment 640 policies for the registries of code points for these sub-TLVs, values 641 must be assigned by IANA [RFC3630]. 643 This draft requests early allocation of IANA code points in 644 accordance with [RFC4020]. [NOTE TO RFC Editor: this paragraph and 645 the RFC 4020 reference can be removed during RFC editing]. 647 The following subsections summarize the required sub-TLVs. 649 10.1. Sub-TLVs of the Link TLV 651 This document defines the following sub-TLVs of the Link TLV 652 advertised in the OSPF TE LSA: 654 - Local and Remote TE Router ID sub-TLV (TBDx) 655 - Inter-RA Export Upward sub-TLV (TBDy) 656 - Inter-RA Export Downward sub-TLV (TBDz) 657 Codepoints for these Sub-TLVs should be allocated from the "Types for 658 sub-TLVs of TE Link TLV (Value 2)" registry standards action range (0 659 - 32767) [RFC3630]. 661 Note that the same values for the Inter-RA Export Upward sub-TLV and 662 the Inter-RA Export Downward Sub-TLV MUST be used when they appear in 663 the Link TLV, Node Attribute TLV, and Router Address TLV. 665 10.2. Sub-TLVs of the Node Attribute TLV 667 This document defines the following sub-TLVs of the Node Attribute 668 TLV advertised in the OSPF TE LSA: 670 - Local TE Router ID sub-TLV (5) 671 - Inter-RA Export Upward sub-TLV (TDBy) 672 - Inter-RA Export Downward sub-TLV (TBDz) 674 Codepoints for these Sub-TLVs should be assigned from the "Types for 675 sub-TLVs of TE Node Attribute TLV (Value 5)" registry standards 676 action range (0 - 32767) [RFC5786]. 678 Note that the same values for the Inter-RA Export Upward sub-TLV and 679 the Inter-RA Export Downward Sub-TLV MUST be used when they appear in 680 the Link TLV, Node Attribute TLV, and Router Address TLV. 682 10.3. Sub-TLVs of the Router Address TLV 684 The Router Address TLV is advertised in the OSPF TE LSA [RFC3630]. 685 Since this TLV currently has no Sub-TLVs defined, a "Types for sub- 686 TLVs of Router Address TLV (Value 1)" registry must be defined. 688 The registry guidelines for the assignment of types for sub-TLVs of 689 the Router Address TLV are as follows: 691 o Types in the range 0-32767 are to be assigned via Standards 692 Action. 694 o Types in the range 32768-32777 are for experimental use; these 695 will not be registered with IANA, and MUST NOT be mentioned by 696 RFCs. 698 o Types in the range 32778-65535 are not to be assigned at this 699 time. Before any assignments can be made in this range, there 700 MUST be a Standards Track RFC that specifies IANA 701 Considerations that covers the range being assigned. 703 This document defines the following sub-TLVs for inclusion in the 704 Router Address TLV: 706 - Inter-RA Export Upward sub-TLV (TBDy) 707 - Inter-RA Export Downward sub-TLV (TBDz) 709 Codepoints for these Sub-TLVs should be allocated from the "Types for 710 sub-TLVs of Router Address TLV (Value 1)" registry standards action 711 range (0 - 32767). 713 Note that the same values for the Inter-RA Export Upward sub-TLV and 714 the Inter-RA Export Downward Sub-TLV MUST be used when they appear in 715 the Link TLV, Node Attribute TLV, and Router Address TLV. 717 11. Management Considerations 719 11.1. Routing Area (RA) Isolation 721 If the RA Identifier is mapped to the OSPF Area ID as recommended in 722 section 2.0, OSPF [RFC2328] implicitly provides isolation. On any 723 intra-RA link, packets will only be accepted if the area-id in the 724 OSPF packet header matches the area ID for the OSPF interface on 725 which the packet was received. Hence, RCs will only establish 726 adjacencies and exchange reachability information (see Section 4.0) 727 with RCs in the same RC. Other mechanisms for RA isolation are 728 beyond the scope of this document. 730 11.2 Routing Area (RA) Topology/Configuration Changes 732 The GMPLS Routing for ASON requirements [RFC4258] dictate that the 733 routing protocol MUST support reconfiguration and SHOULD support 734 architectural evolution. OSPF [RFC2328] includes support for the 735 dynamic introduction or removal of ASON reachability information 736 through the flooding and purging of OSPF opaque LSAs [RFC5250]. Also, 737 when an RA is partitioned or an RC fails, stale LSAs SHOULD NOT be 738 used unless the advertising RC is reachable. The configuration of 739 OSPF RAs and the policies governing the redistribution of ASON 740 reachability information between RAs are implementation issues 741 outside of the OSPF routing protocol and beyond the scope of this 742 document. 744 12. Comparison to Requirements in RFC 4258 746 The following table shows how this draft complies with the 747 requirements in [RFC4258]. The first column contains a requirements 748 number (1-30) and the relevant section in RFC 4258. The second column 749 describes the requirement, the third column discusses the compliance 750 to that requirement, and the fourth column lists the relevant section 751 in draft, and/or another RFC that already satisfies the requirement. 753 +----------+---------------------------+---------------+-------------+ 754 | RFC 4258 | RFC 4258 Requirement | Compliance | Reference | 755 | Section | | | | 756 | (Req. | | | | 757 | Number) | | | | 758 +----------+---------------------------+---------------+-------------+ 759 | 3.0 (1) | The failure of an RC, or | Implied by | Not an | 760 | | the failure of | separation of |attribute of | 761 | |communications between RCs,| transport and | routing | 762 | |and the subsequent recovery|control plane. | protocol. | 763 | |from the failure condition | | | 764 | | MUST NOT disrupt call in | | | 765 | | progress. | | | 766 +----------+---------------------------+---------------+-------------+ 767 | 3.1 (2) |Multiple Hierarchical Level| Yes | Sections 2 | 768 | | of ASON Routing Areas | | and 3 | 769 | | (RAs). | | | 770 +----------+---------------------------+---------------+-------------+ 771 | 3.1 (3) | Prior to establishing | Yes, when RA |Section 11.1 | 772 | | communications, RCs MUST | maps to OSPF | | 773 | |verify that they are bound | Area ID. | | 774 | | to the same parent RA. | Otherwise, | | 775 | | | out of scope. | | 776 +----------+---------------------------+---------------+-------------+ 777 | 3.1 (4) | The RC ID MUST be unique | Yes |RFC 2328 and | 778 | | within its containing RA. | | Section 3. | 779 +----------+---------------------------+---------------+-------------+ 780 | 3.1 (5) |Each RA within a carrier's |Yes - although | Sections 2, | 781 | | network SHALL be uniquely | uniqueness is | 3, and 11.1 | 782 | |identifiable. RA IDs MAY be|the operator's | | 783 | |associated with a transport|responsibility.| | 784 | | plane name space, whereas | | | 785 | |RC IDs are associated with | | | 786 | |a control plane name space.| | | 787 +----------+---------------------------+---------------+-------------+ 788 | 3.2 (6) | Hierarchical Routing | Yes | Section 7 | 789 | | Information Dissemination | | | 790 +----------+---------------------------+---------------+-------------+ 791 | 3.2 (7) | Routing Information | Yes | Section 7.1 | 792 | |exchanged between levels N | | | 793 | | and N+1 via separate | | | 794 | | instances and | | | 795 | | import/export. | | | 796 +----------+---------------------------+---------------+-------------+ 797 +----------+---------------------------+---------------+-------------+ 798 | 3.2 (8) | Routing Information | No - Not | | 799 | |exchanged between levels N | described. | | 800 | | and N+1 via external link | | | 801 | | (inter-RA links). | | | 802 +----------+---------------------------+---------------+-------------+ 803 | 3.2 (9) | Routing information | Yes | Sections 4, | 804 | | exchange MUST include | |6, 6.1, 6.2, | 805 | | reachability information | | and 8 | 806 | | and MAY include, upon | | | 807 | | policy decision, node and | | | 808 | | link topology. | | | 809 +----------+---------------------------+---------------+-------------+ 810 | 3.2 (10) | There SHOULD NOT be any |Yes - separate | Sections 2 | 811 | | dependencies on the | instances. | and 3 | 812 | |different routing protocols| | | 813 | | used within an RA or in | | | 814 | | different RAs. | | | 815 +----------+---------------------------+---------------+-------------+ 816 | 3.2 (11) |The routing protocol SHALL | Yes | Section 7.2 | 817 | | differentiate the routing | | | 818 | |information originated at a| | | 819 | |given-level RA from derived| | | 820 | | routing information | | | 821 | | (received from external | | | 822 | | RAs), even when this | | | 823 | |information is forwarded by| | | 824 | | another RC at the same | | | 825 | | level. | | | 826 +----------+---------------------------+---------------+-------------+ 827 | 3.2 (12) | The routing protocol MUST | Yes | Section 7.2 | 828 | | provide a mechanism to | | | 829 | | prevent information | | | 830 | |propagated from a Level N+1| | | 831 | | RA's RC into the Level N | | | 832 | | RA's RC from being | | | 833 | | re-introduced into the | | | 834 | | Level N+1 RA's RC. | | | 835 +----------+---------------------------+---------------+-------------+ 836 | 3.2 (13) | The routing protocol MUST | Yes | Section 7.2 | 837 | | provide a mechanism to | | | 838 | | prevent information | | | 839 | |propagated from a Level N-1| | | 840 | | RA's RC into the Level N | | | 841 | | RA's RC from being | | | 842 | | re-introduced into the | | | 843 | | Level N-1 RA's RC. | | | 844 +----------+---------------------------+---------------+-------------+ 845 +----------+---------------------------+---------------+-------------+ 846 | 3.2 (14) | Instance of a Level N | Yes | Sections 2, | 847 | | routing function and an | | 3, and 7 | 848 | | instance of a Level N+1 | | | 849 | | routing function in the | | | 850 | | same system. | | | 851 +----------+---------------------------+---------------+-------------+ 852 | 3.2 (15) | The Level N routing | Not described | N/A | 853 | | function is on a separate | but possible. | | 854 | | system the Level N+1 | | | 855 | | routing function. | | | 856 +----------+---------------------------+---------------+-------------+ 857 | 3.3 (16) |The RC MUST support static | The automation| Sections 2 | 858 | | (i.e., operator assisted) | requirement is|and 3. Config| 859 | | and MAY support automated | ambiguous. | is product | 860 | | configuration of the | OSPF supports | specific. | 861 | |information describing its | auto-discovery| Refer to | 862 | |relationship to its parent | of neighbors | RFC 2328 for| 863 | | and its child within the | and topology. | OSPF auto- | 864 | | hierarchical structure | Default and | discovery. | 865 | | (including RA ID and RC | automatically | | 866 | | ID). | configured | | 867 | | | polices are | | 868 | | | out of scope. | | 869 +----------+---------------------------+---------------+-------------+ 870 | 3.3 (17) |The RC MUST support static |Yes - when OSPF|RFC 2328 and | 871 | | (i.e., operator assisted) |area maps to RA|Section 11.1 | 872 | | and MAY support automated | discovery is | | 873 | | configuration of the | automatic. | | 874 | |information describing its | | | 875 | | associated adjacencies to | | | 876 | | other RCs within an RA. | | | 877 +----------+---------------------------+---------------+-------------+ 878 | 3.3 (18) |The routing protocol SHOULD| Yes | RFC 2328 | 879 | |support all the types of RC| | | 880 | | adjacencies described in | | | 881 | |Section 9 of [G.7715]. The | | | 882 | | latter includes congruent | | | 883 | |topology (with distributed | | | 884 | | RC) and hubbed topology | | | 885 | |(e.g., note that the latter| | | 886 | | does not automatically | | | 887 | | imply a designated RC). | | | 888 +----------+---------------------------+---------------+-------------+ 889 +----------+---------------------------+---------------+-------------+ 890 | 3.4 (19) |The routing protocol SHOULD| Yes |RFC 2328, RFC| 891 | | be capable of supporting | | 5250, and | 892 | |architectural evolution in | |Section 11.2.| 893 | | terms of the number of | | | 894 | |hierarchical levels of RAs,| | | 895 | |as well as the aggregation | | | 896 | | and segmentation of RAs. | | | 897 +----------+---------------------------+---------------+-------------+ 898 |3.5.2 (20)|Advertisements MAY contain | | | 899 | |the following common set of| | | 900 | | information regardless of | | | 901 | | whether they are link or | | | 902 | | node related: | | | 903 | | - RA ID of the RA to | Yes |Section 7.2.1| 904 | |which the advertisement is | | | 905 | | bounded | | | 906 | | - RC ID of the entity | Yes | RFC 2328 | 907 | | generating the | | | 908 | | advertisement | | | 909 | | - Information to | Yes |RFC 2328, RFC| 910 | | uniquely identify | | 5250 | 911 | | advertisements | | | 912 | | - Information to | No - Must | | 913 | | determine whether an |compare to old | | 914 | | advertisement has been | | | 915 | | updated | | | 916 | | - Information to | Yes |Section 7.2.1| 917 | | indicate when an | | | 918 | | advertisement has been | | | 919 | | derived from a different | | | 920 | | level RA | | | 921 +----------+---------------------------+---------------+-------------+ 922 |3.5.3 (21)|The Node Attributes Node ID|Yes - Prefixes | RFC 5786, | 923 | | and Reachability must be | only for |Section 4 and| 924 | | advertised. It MAY be | reachability | 6 | 925 | | advertised as a set of | | | 926 | |associated external (e.g., | | | 927 | | User Network Interface | | | 928 | | (UNI)) address/address | | | 929 | | prefixes or a set of | | | 930 | | associated SNPP link | | | 931 | | IDs/SNPP ID prefixes, the | | | 932 | |selection of which MUST be | | | 933 | | consistent within the | | | 934 | | applicable scope. | | | 935 +----------+---------------------------+---------------+-------------+ 936 +----------+---------------------------+---------------+-------------+ 937 |3.5.4 (22)| The Link Attributes Local | Yes | Section 6.1 | 938 | | SNPP link ID, Remote SNPP | | | 939 | |link ID, and layer specific| | | 940 | | characteristics must be | | | 941 | | advertised. | | | 942 +----------+---------------------------+---------------+-------------+ 943 |3.5.4 (23)| Link Signaling Attributes | Yes | Section 5, | 944 | |other than Local Adaptation| | RFC 4652 - | 945 | |(Signal Type, Link Weight, | |Section 5.3.1| 946 | | Resource Class, Local | | | 947 | | Connection Types, Link | | | 948 | | Capacity, Link | | | 949 | | Availability, Diversity | | | 950 | | Support) | | | 951 +----------+---------------------------+---------------+-------------+ 952 |3.5.4 (24)| Link Signaling Local | Yes | Section 5.1 | 953 | | Adaptation | | | 954 +----------+---------------------------+---------------+-------------+ 955 | 5 (25) | The routing adjacency | Yes |Section 2, 3,| 956 | | topology (i.e., the | | and 6 | 957 | |associated PC connectivity | | | 958 | |topology) and the transport| | | 959 | |network topology SHALL NOT | | | 960 | |be assumed to be congruent.| | | 961 +----------+---------------------------+---------------+-------------+ 962 | 5 (26) |The routing topology SHALL | Yes |RFC 2328, RFC| 963 | | support multiple links | | 3630 | 964 | | between nodes and RAs. | | | 965 +----------+---------------------------+---------------+-------------+ 966 | 5 (27) |The routing protocol SHALL | Yes |RFC 2328, RFC| 967 | | converge such that the | | 5250 | 968 | | distributed RDBs become | | | 969 | |synchronized after a period| | | 970 | | of time. | | | 971 +----------+---------------------------+---------------+-------------+ 972 | 5 (28) |Self-consistent information|Yes - However, | Section 7.1 | 973 | | at the receiving level | this is not a | | 974 | | resulting from any | routing | | 975 | | transformation (filter, | protocol | | 976 | | summarize, etc.) and | function. | | 977 | | forwarding of information | | | 978 | | from one RC to RC(s) at | | | 979 | | different levels when | | | 980 | |multiple RCs are bound to a| | | 981 | | single RA. | | | 982 +----------+---------------------------+---------------+-------------+ 983 +----------+---------------------------+---------------+-------------+ 984 | 5 (29) | In order to support |Partial - OSPF |RFC 2328 and | 985 | | operator-assisted changes | supports the | RFC 5250 | 986 | | in the containment | purging of | | 987 | | relationships of RAs, the | stale | | 988 | | routing protocol SHALL |advertisements | | 989 | |support evolution in terms |and origination| | 990 | | of the number of | of new. The | | 991 | |hierarchical levels of RAs.|non-disruptive | | 992 | | For example: support of | behavior is | | 993 | | non-disruptive operations |implementation | | 994 | |such as adding and removing| specific. | | 995 | | RAs at the top/bottom of | | | 996 | | the hierarchy, adding or | | | 997 | | removing a hierarchical | | | 998 | |level of RAs in or from the| | | 999 | |middle of the hierarchy, as| | | 1000 | | well as aggregation and | | | 1001 | | segmentation of RAs. | | | 1002 +----------+---------------------------+---------------+-------------+ 1003 | 5 (30) | A collection of links and |Yes - Within an| Sections 4 | 1004 | |nodes such as a subnetwork | RA it must be | and 6 | 1005 | | or RA MUST be able to | consistent. | | 1006 | | represent itself to the | | | 1007 | | wider network as a single | | | 1008 | | logical entity with only | | | 1009 | |its external links visible | | | 1010 | | to the topology database. | | | 1011 +----------+---------------------------+---------------+-------------+ 1013 13. References 1015 13.1. Normative References 1017 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 1018 Requirement Levels", BCP 14, RFC 2119, March 1997. 1020 [RFC2328] Moy, J., "OSPF Version 2", STD 54, RFC 2328, April 1998. 1022 [RFC3630] Katz, D., Kompella, K., and D. Yeung, "Traffic 1023 Engineering (TE) Extensions to OSPF Version 2", RFC 1024 3630, September 2003. 1026 [RFC3945] Mannie, E., Ed., "Generalized Multi-Protocol Label 1027 Switching (GMPLS) Architecture", RFC 3945, October 2004. 1029 [RFC4202] Kompella, K., Ed., and Y. Rekhter, Ed., "Routing 1030 Extensions in Support of Generalized Multi-Protocol 1031 Label Switching (GMPLS)", RFC 4202, October 2005. 1033 [RFC4203] Kompella, K., Ed., and Y. Rekhter, Ed., "OSPF Extensions 1034 in Support of Generalized Multi-Protocol Label Switching 1035 (GMPLS)", RFC 4203, October 2005. 1037 [RFC5250] Berger, L., Bryskin, I., Zinin, A., and R. Coltun, "The 1038 OSPF Opaque LSA Option", RFC 5250, July 2008. 1040 [RFC5786] Aggarwal, R. and K. Kompella, "Advertising a Router's 1041 Local Addresses in OSPF TE Extensions", RFC 5786, March 1042 2010. 1044 13.2. Informative References 1046 [RFC2154] Murphy, S., Badger, M., and B. Wellington, "OSPF with 1047 Digital Signatures", RFC 2154, June 1997. 1049 [RFC4020] Kompella, K. and A. Zinin, "Early IANA Allocation of 1050 Standards Track Code Points", BCP 100, RFC 4020, 1051 February 2005. 1053 [RFC4258] Brungard, D., Ed., "Requirements for Generalized Multi- 1054 Protocol Label Switching (GMPLS) Routing for the 1055 Automatically Switched Optical Network (ASON)", RFC 1056 4258, November 2005. 1058 [RFC4652] Papadimitriou, D., Ed., Ong, L., Sadler, J., Shew, S., 1059 and D. Ward, "Evaluation of Existing Routing Protocols 1060 against Automatic Switched Optical Network (ASON) 1061 Routing Requirements", RFC 4652, October 2006. 1063 [RFC5709] Bhatia, M., Manral, V., Fanto, M., White, R., Barnes, 1064 M., Li, T., and R. Atkinson, "OSPFv2 HMAC-SHA 1065 Cryptographic Authentication", RFC 5709, October 2009. 1067 For information on the availability of ITU Documents, please see 1068 http://www.itu.int. 1070 [G.7715] ITU-T Rec. G.7715/Y.1306, "Architecture and Requirements 1071 for the Automatically Switched Optical Network (ASON)", 1072 June 2002. 1074 [G.7715.1] ITU-T Rec. G.7715.1/Y.1706.1, "ASON Routing Architecture 1075 and Requirements for Link State Protocols", February 1076 2004. 1078 [G.805] ITU-T Rec. G.805, "Generic Functional Architecture of 1079 Transport Networks)", March 2000. 1081 [G.8080] ITU-T Rec. G.8080/Y.1304, "Architecture for the 1082 Automatically Switched Optical Network (ASON)," June 1083 2006 (and Amendments 1 (March 2008) and 2 (Sept. 2010)). 1085 14. Acknowledgements 1087 The editors would like to thank Lyndon Ong, Remi Theillaud, Stephen 1088 Shew, Jonathan Sadler, Deborah Brungard, Lou Berger, and Adrian 1089 Farrel for their useful comments and suggestions. 1091 14.1 RFC 5787 Acknowledgements 1093 The author would like to thank Dean Cheng, Acee Lindem, Pandian 1094 Vijay, Alan Davey, Adrian Farrel, Deborah Brungard, and Ben Campbell 1095 for their useful comments and suggestions. 1097 Lisa Dusseault and Jari Arkko provided useful comments during IESG 1098 review. 1100 Question 14 of Study Group 15 of the ITU-T provided useful and 1101 constructive input. 1103 Appendix A. ASON Terminology 1105 This document makes use of the following terms: 1107 Administrative domain: (See Recommendation [G.805].) For the 1108 purposes of [G7715.1], an administrative domain represents the 1109 extent of resources that belong to a single player such as a 1110 network operator, a service provider, or an end-user. 1111 Administrative domains of different players do not overlap amongst 1112 themselves. 1114 Control plane: performs the call control and connection control 1115 functions. Through signaling, the control plane sets up and 1116 releases connections, and may restore a connection in case of a 1117 failure. 1119 (Control) Domain: represents a collection of (control) entities that 1120 are grouped for a particular purpose. The control plane is 1121 subdivided into domains matching administrative domains. Within 1122 an administrative domain, further subdivisions of the control 1123 plane are recursively applied. A routing control domain is an 1124 abstract entity that hides the details of the RC distribution. 1126 External NNI (E-NNI): interfaces located between protocol controllers 1127 between control domains. 1129 Internal NNI (I-NNI): interfaces located between protocol controllers 1130 within control domains. 1132 Link: (See Recommendation G.805.) A "topological component" that 1133 describes a fixed relationship between a "subnetwork" or "access 1134 group" and another "subnetwork" or "access group". Links are not 1135 limited to being provided by a single server trail. 1137 Management plane: performs management functions for the transport 1138 plane, the control plane, and the system as a whole. It also 1139 provides coordination between all the planes. The following 1140 management functional areas are performed in the management plane: 1141 performance, fault, configuration, accounting, and security 1142 management. 1144 Management domain: (See Recommendation G.805.) A management domain 1145 defines a collection of managed objects that are grouped to meet 1146 organizational requirements according to geography, technology, 1147 policy, or other structure, and for a number of functional areas 1148 such as configuration, security, (FCAPS), for the purpose of 1149 providing control in a consistent manner. Management domains can 1150 be disjoint, contained, or overlapping. As such, the resources 1151 within an administrative domain can be distributed into several 1152 possible overlapping management domains. The same resource can 1153 therefore 1154 belong to several management domains simultaneously, but a 1155 management domain shall not cross the border of an administrative 1156 domain. 1158 Subnetwork Point (SNP): The SNP is a control plane abstraction that 1159 represents an actual or potential transport plane resource. SNPs 1160 (in different subnetwork partitions) may represent the same 1161 transport resource. A one-to-one correspondence should not be 1162 assumed. 1164 Subnetwork Point Pool (SNPP): A set of SNPs that are grouped together 1165 for the purposes of routing. 1167 Termination Connection Point (TCP): A TCP represents the output of a 1168 Trail Termination function or the input to a Trail Termination 1169 Sink function. 1171 Transport plane: provides bidirectional or unidirectional transfer of 1172 user information, from one location to another. It can also 1173 provide transfer of some control and network management 1174 information. The transport plane is layered; it is equivalent to 1175 the Transport Network defined in Recommendation G.805. 1177 User Network Interface (UNI): interfaces are located between protocol 1178 controllers between a user and a control domain. Note: There is 1179 no routing function associated with a UNI reference point. 1181 Appendix B. ASON Routing Terminology 1183 This document makes use of the following terms: 1185 Routing Area (RA): an RA represents a partition of the data plane, 1186 and its identifier is used within the control plane as the 1187 representation of this partition. Per [G.8080], an RA is defined 1188 by a set of sub-networks, the links that interconnect them, and 1189 the interfaces representing the ends of the links exiting that RA. 1190 An RA may contain smaller RAs inter-connected by links. The 1191 limit of subdivision results in an RA that contains two sub- 1192 networks interconnected by a single link. 1194 Routing Database (RDB): a repository for the local topology, network 1195 topology, reachability, and other routing information that is 1196 updated as part of the routing information exchange and may 1197 additionally contain information that is configured. The RDB may 1198 contain routing information for more than one routing area (RA). 1200 Routing Components: ASON routing architecture functions. These 1201 functions can be classified as protocol independent (Link Resource 1202 Manager or LRM, Routing Controller or RC) or protocol specific 1203 (Protocol Controller or PC). 1205 Routing Controller (RC): handles (abstract) information needed for 1206 routing and the routing information exchange with peering RCs by 1207 operating on the RDB. The RC has access to a view of the RDB. 1208 The RC is protocol independent. 1210 Note: Since the RDB may contain routing information pertaining to 1211 multiple RAs (and possibly to multiple layer networks), the RCs 1212 accessing the RDB may share the routing information. 1214 Link Resource Manager (LRM): supplies all the relevant component and 1215 TE link information to the RC. It informs the RC about any state 1216 changes of the link resources it controls. 1218 Protocol Controller (PC): handles protocol-specific message exchanges 1219 according to the reference point over which the information is 1220 exchanged (e.g., E-NNI, I-NNI), and internal exchanges with the 1221 RC. The PC function is protocol dependent. 1223 Authors' Addresses 1225 Andrew G. Malis 1226 Verizon Communications 1227 117 West St. 1228 Waltham MA 02451 USA 1230 EMail: andrew.g.malis@verizon.com 1232 Acee Lindem 1233 Ericsson 1234 102 Carric Bend Court 1235 Cary, NC 27519 1237 EMail: acee.lindem@ericsson.com 1239 Dimitri Papadimitriou 1240 Alcatel-Lucent 1241 Copernicuslaan, 50 1242 2018 Antwerpen, Belgium 1244 EMail: dimitri.papadimitriou@alcatel-lucent.com