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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) -- Obsolete informational reference (is this intentional?): RFC 4020 (Obsoleted by RFC 7120) Summary: 0 errors (**), 0 flaws (~~), 1 warning (==), 2 comments (--). Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 2 INTERNET-DRAFT A. Malis, ed. 3 Intended Status: Proposed Standard Verizon Communications 4 Expires: February 9, 2012 A. Lindem, ed. 5 Ericsson 6 D. Papadimitriou, ed. 7 Alcatel-Lucent 8 August 8, 2011 10 Updates to ASON Routing for OSPFv2 Protocols (RFC 5787bis) 11 draft-ietf-ccamp-rfc5787bis-03.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. It is inappropriate to use Internet-Drafts as reference 26 material or to cite them other than as "work in progress." 28 The list of current Internet-Drafts can be accessed at 29 http://www.ietf.org/1id-abstracts.html 31 The list of Internet-Draft Shadow Directories can be accessed at 32 http://www.ietf.org/shadow.html 34 Copyright and License Notice 36 Copyright (c) 2011 IETF Trust and the persons identified as the 37 document authors. All rights reserved. 39 This document is subject to BCP 78 and the IETF Trust's Legal 40 Provisions Relating to IETF Documents 41 (http://trustee.ietf.org/license-info) in effect on the date of 42 publication of this document. Please review these documents 43 carefully, as they describe your rights and restrictions with respect 44 to this document. 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. 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, etc. 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 SCN addresses. This section discusses the mapping 218 between ASON routing identifiers and corresponding identifiers 219 defined for GMPLS routing, and how these support the physical (or 220 logical) separation of transport plane entities and control plane 221 components. GMPLS supports this separation of identifiers and 222 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 transport plane 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 Note: The Router Address top-level TLV definition, processing, and 234 usage are unchanged from [RFC3630]. This TLV specifies a stable OSPF 235 TE node IP address, i.e., the IP address is always reachable when 236 there is IP connectivity to the associated OSPF TE node. 238 ASON defines a Routing Controller (RC) as an entity that handles 239 (abstract) information needed for routing and the routing information 240 exchange with peering RCs by operating on the Routing Database (RDB). 241 ASON defines a Protocol Controller (PC) as an entity that handles 242 protocol-specific message exchanges according to the reference point 243 over which the information is exchanged (e.g., E-NNI, I-NNI), and 244 internal exchanges with the Routing Controller (RC) [RFC4258]. In 245 this document, an OSPF router advertising ASON TE topology 246 information will perform both the functions of the RC and PC. Each 247 OSPF router is uniquely identified by its OSPF Router ID [RFC2328]. 249 4. Reachability 251 Reachability in ASON refers to the set of endpoints reachable in the 252 transport plane by a node or the reachable endpoints of a level N. 253 Reachable entities are identified in the transport plane name space 254 (ASON SNPP name space). In order to advertise blocks of reachable 255 address prefixes, a summarization mechanism is introduced that is 256 based on the techniques described in [RFC5786]. For ASON reachability 257 advertisement, blocks of reachable address prefixes are advertised 258 together with the associated data plane node. The data plane node is 259 identified in the control plane by its TE Router ID, as discussed in 260 section 6. 262 In order to support ASON reachability advertisement, the Node 263 Attribute TLV defined in [RFC5786] is used to advertise the 264 combination of a TE Router ID and its set of associated reachable 265 address prefixes. The Node Attribute TLV can contain the following 266 sub-TLVs: 268 - TE Router ID sub-TLV: Length: 4; Defined in Section 6.2 269 - Node IPv4 Local Address sub-TLV: Length: variable; [RFC5786] 270 - Node IPv6 Local Address sub-TLV: Length: variable; [RFC5786] 272 A router may support multiple transport nodes as discussed in section 273 6, and, as a result, may be required to advertise reachability (ASON 274 SNPPs) separately for each transport node. As a consequence, it MUST 275 be possible for the router to originate more than one TE LSA 276 containing the Node Attribute TLV when used for ASON reachability 277 advertisement. 279 Hence, the Node Attribute TLV [RFC5786] advertisement rules must be 280 relaxed for ASON. A Node Attribute TLV MAY appear in more than one TE 281 LSA originated by the RC when the RC is advertising reachability 282 information for a different transport node identified by the Local TE 283 Router Sub-TLV (refer to section 6.1). 285 5. Link Attribute 287 With the exception of local adaptation (described below), the mapping 288 of link attributes and characteristics to OSPF TE Link TLV Sub-TLVs 289 is unchanged [RFC4652]. OSPF TE Link TLV Sub-TLVs are described in 290 [RFC3630] and [RFC4203]. Advertisement of this information SHOULD be 291 supported on a per-layer basis, i.e., one TE LSA per unique switching 292 capability and bandwidth granularity combination. 294 5.1. Local Adaptation 296 Local adaptation is defined as a TE link attribute (i.e., sub-TLV) 297 that describes the cross/inter-layer relationships. 299 The Interface Switching Capability Descriptor (ISCD) TE Attribute 300 [RFC4202] identifies the ability of the TE link to support cross- 301 connection to another link within the same layer. When advertising 302 link adaptation, it also identifies the ability to use a locally 303 terminated connection that belongs to one layer as a data link for 304 another layer (adaptation capability). However, the information 305 associated with the ability to terminate connections within that 306 layer (referred to as the termination capability) is advertised with 307 the adaptation capability. 309 For instance, a link between two optical cross-connects will contain 310 at least one ISCD attribute describing the Lambda Switching Capable 311 (LSC) switching capability. Conversely, a link between an optical 312 cross-connect and an IP/MPLS Label Switching Router (LSR) will 313 contain at least two ISCD attributes, one for the description of the 314 LSC termination capability and one for the Packet Switching Capable 315 (PSC) adaptation capability. 317 In OSPFv2, the Interface Switching Capability Descriptor (ISCD) is a 318 sub-TLV (type 15) of the top-level Link TLV (type 2) [RFC4203]. The 319 adaptation and termination capabilities are advertised using two 320 separate ISCD sub-TLVs within the same top-level Link TLV. 322 An interface MAY have more than one ISCD sub-TLV, [RFC4202] and 323 [RFC4203]. Hence, the corresponding advertisements should not result 324 in any compatibility issues. 326 5.2. Bandwidth Accounting 328 GMPLS routing defines an Interface Switching Capability Descriptor 329 (ISCD) that provides, among other things, the available 330 (maximum/minimum) bandwidth per priority available for Label Switched 331 Path (LSPs). One or more ISCD sub-TLVs can be associated with an 332 interface, [RFC4202] and [RFC4203]. This information, combined with 333 the Unreserved Bandwidth Link TLV sub-TLV [RFC3630], provides the 334 basis for bandwidth accounting. 336 In the ASON context, additional information may be included when the 337 representation and information in the other advertised fields are not 338 sufficient for a specific technology, e.g., SDH. The definition of 339 technology-specific information elements is beyond the scope of this 340 document. Some technologies will not require additional information 341 beyond what is already defined in [RFC3630], [RFC4202], and 342 [RFC4203]. 344 6. Routing Information Scope 346 For ASON routing, the control plane component routing adjacency 347 topology (i.e., the associated Protocol Controller (PC) connectivity) 348 and the transport topology are NOT assumed to be congruent [RFC4258]. 349 Hence, a single OSPF router (i.e., the PC) MUST be able to advertise 350 on behalf of multiple transport layer nodes. The OSPF routers are 351 identified by OSPF Router ID and the transport nodes are identified 352 by TE Router ID. 354 The Router Address TLV [RFC3630] is used to advertise the TE Router 355 ID associated with the advertising Routing Controller. TE Router IDs 356 for additional transport nodes are advertised through specification 357 of the Local TE Router Identifier in the Local and Remote TE Router 358 TE sub-TLV and the Local TE Router Identifier sub-TLV described in 359 the sections below. These Local TE Router Identifiers are typically 360 used as the local endpoints for TE Label Switched Paths (LSPs) 361 terminating on the associated transport node. 363 It MAY be feasible for multiple OSPF Routers to advertise TE 364 information for the same transport node. However, this is not 365 considered a required use case and is not discussed further. 367 6.1. Link Advertisement (Local and Remote TE Router ID Sub-TLV) 369 An OSPF router advertising on behalf of multiple transport nodes will 370 require additional information to distinguish the link endpoints 371 amongst the subsumed transport nodes. In order to unambiguously 372 specify the transport topology, the local and remote transport nodes 373 MUST be identified by TE router ID. 375 For this purpose, a new sub-TLV of the OSPFv2 TE LSA top-level Link 376 TLV is introduced that defines the Local and Remote TE Router ID. 378 The Type field of the Local and Remote TE Router ID sub-TLV is 379 assigned the value 26 (see Section 10). The Length field takes the 380 value 8. The Value field of this sub-TLV contains 4 octets of the 381 Local TE Router Identifier followed by 4 octets of the Remote TE 382 Router Identifier. The value of the Local and Remote TE Router 383 Identifier SHOULD NOT be set to 0. 385 The format of the Local and Remote TE Router ID sub-TLV is: 387 0 1 2 3 388 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 1 389 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 390 | Type (26) | Length (8) | 391 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 392 | Local TE Router Identifier | 393 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 394 | Remote TE Router Identifier | 395 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 397 This sub-TLV MUST be included as a sub-TLV of the top-level Link TLV 398 if the OSPF router is advertising on behalf of one or more transport 399 nodes having TE Router IDs different from the TE Router ID advertised 400 in the Router Address TLV. Therefore, it MUST be included if the 401 OSPF router is advertising on behalf of multiple transport nodes. 403 Note: The Link ID sub-TLV identifies the other end of the link (i.e., 404 Router ID of the neighbor for point-to-point links) [RFC3630]. When 405 the Local and Remote TE Router ID Sub-TLV is present, it MUST be used 406 to identify local and remote transport node endpoints for the link 407 and the Link-ID sub-TLV MUST be ignored. The Local and Remote ID sub- 408 TLV, if specified, MUST only be specified once. 410 6.2. Reachability Advertisement (Local TE Router ID sub-TLV) 412 When an OSPF router is advertising on behalf of multiple transport 413 nodes, the routing protocol MUST be able to associate the advertised 414 reachability information with the correct transport node. 416 For this purpose, a new sub-TLV of the OSPFv2 TE LSA top-level Node 417 Attribute TLV is introduced. This TLV associates the local prefixes 418 (see above) to a given transport node identified by TE Router ID. 420 The Type field of the Local TE Router ID sub-TLV is assigned the 421 value 5 (see Section 10). The Length field takes the value 4. The 422 Value field of this sub-TLV contains the Local TE Router Identifier 423 [RFC3630] encoded over 4 octets. 425 The format of the Local TE Router ID sub-TLV is: 427 0 1 2 3 428 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 1 429 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 430 | Type (5) | Length (4) | 431 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 432 | Local TE Router Identifier | 433 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 435 This sub-TLV MUST be included as a sub-TLV of the top-level Node 436 Attribute TLV if the OSPF router is advertising on behalf of one or 437 more transport nodes having TE Router IDs different from the TE 438 Router ID advertised in the Router Address TLV. Therefore, it MUST 439 be included if the OSPF router is advertising on behalf of multiple 440 transport nodes. 442 7. Routing Information Dissemination 444 An ASON routing area (RA) represents a partition of the data plane, 445 and its identifier is used within the control plane as the 446 representation of this partition. An RA may contain smaller RAs 447 inter-connected by links. ASON RA levels do not map directly to OSPF 448 areas. Rather, hierarchical levels of RAs are represented by separate 449 OSPF protocol instances. 451 Routing controllers (RCs) supporting multiple RAs disseminate 452 information downward and upward in this ASON hierarchy. The vertical 453 routing information dissemination mechanisms described in this 454 section do not introduce or imply hierarchical OSPF areas. RCs 455 supporting RAs at multiple levels are structured as separate OSPF 456 instances with routing information exchange between levels described 457 by import and export rules between these instances. The functionality 458 described herein does not pertain to OSPF areas or OSPF Area Border 459 Router (ABR) functionality. 461 7.1 Import/Export Rules 463 RCs supporting RAs disseminate information upward and downward in the 464 hierarchy by importing/exporting routing information as TE LSAs. TE 465 LSAs are area-scoped opaque LSAs with opaque type 1 [RFC3630]. The 466 information that MAY be exchanged between adjacent levels includes 467 the Router Address, Link, and Node Attribute top-level TLVs. 469 The imported/exported routing information content MAY be transformed, 470 e.g., filtered or aggregated, as long as the resulting routing 471 information is consistent. In particular, when more than one RC is 472 bound to adjacent levels and both are allowed to import/export 473 routing information, it is expected that these transformations are 474 performed in a consistent manner. Definition of these policy-based 475 mechanisms is outside the scope of this document. 477 In practice, and in order to avoid scalability and processing 478 overhead, routing information imported/exported downward/upward in 479 the hierarchy is expected to include reachability information (see 480 Section 4) and, upon strict policy control, link topology 481 information. 483 7.2 Loop Prevention 485 When more than one RC is bound to an adjacent level of the ASON 486 hierarchy, and is configured to export routing information upward or 487 downward, a specific mechanism is required to avoid looping of 488 routing information. Looping is the re-advertisement of routing 489 information into an RA that had previously advertised that routing 490 information upward or downward into an upper or lower level RA in the 491 ASON hierarchy. For example, without loop prevention mechanisms, this 492 could happen when the RC advertising routing information downward in 493 the hierarchy is not the same one that advertises routing information 494 upward in the hierarchy. 496 7.2.1 Inter-RA Export Upward/Downward Sub-TLVs 498 The Inter-RA Export Sub-TLVs can be used to prevent the re- 499 advertisement of OSPF TE routing information into an RA which 500 previously advertised that information. The type value 28 (see 501 Section 10) will indicate that the associated routing information has 502 been exported downward. The type value 27 (see Section 10) will 503 indicate that the associated routing information has been exported 504 upward. While it is not required for routing information exported 505 downward, both Sub-TLVs will include the Routing Area (RA) ID from 506 the which the routing information was exported. This RA is not 507 necessarily the RA originating the routing information but RA from 508 which the information was immediately exported. 510 These additional Sub-TLVs MAY be included in TE LSAs that include any 511 of the following top-level TLVs: 513 - Router Address top-level TLV 514 - Link top-level TLV 515 - Node Attribute top-level TLV 517 The Type field of the Inter-RA Export Upward and Inter-RA Export 518 Downward sub-TLVs are respectively assigned the values 27 and 28 (see 519 Section 10). The Length field in these Sub-TLVs takes the value 4. 520 The Value field in these sub-TLVs contains the associated RA ID. The 521 RA ID value must be a unique identifier for the RA within the ASON 522 routing domain. 524 The format of the Inter-RA Export Upward and Inter-RA Export Downward 525 Sub-TLVs is graphically depicted below: 527 0 1 2 3 528 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 1 529 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 530 | Upward/Downward Type (27/28) | Length (4) | 531 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 532 | Associated RA ID | 533 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 535 7.2.2 Inter-RA Export Upward/Downward Sub-TLV Processing 537 TE LSAs MAY be imported or exported downward or upward in the ASON 538 routing hierarchy. The direction and advertising RA ID are advertised 539 in an Inter-RA Export Upward/Downward Sub-TLV. They MUST be retained 540 and advertised in the receiving RA with the associated routing 541 information. 543 When exporting routing information upward in the ASON routing 544 hierarchy, any information received from a level above, i.e., tagged 545 with an Inter-RA Export Downward Sub-TLV, MUST NOT be exported 546 upward. Since an RA at level N is contained by a single RA at level 547 N+1, this is the only checking that is necessary and the associated 548 RA ID is used solely for informational purposes. 550 When exporting routing information downward in the ASON routing 551 hierarchy, any information received from a level below, i.e., tagged 552 with an Inter-RA Export Upward Sub-TLV MUST NOT be exported downward 553 if the target RA ID matches the RA ID associated with the routing 554 information. This additional checking is required for routing 555 information exported downward since a single RA at level N+1 may 556 contain multiple RAs at level N in the ASON routing hierarchy. In 557 order words, routing information MUST NOT be exported downward into 558 the RA from which it was received. 560 8. OSPFv2 Scalability 562 The extensions described herein are only applicable to ASON routing 563 domains and it is not expected that the attendant reachability (see 564 Section 4) and link information will ever be mixed with global or 565 local IP routing information. If there were ever a requirement for a 566 given RC to participate in both domains, separate OSPFv2 instances 567 would be utilized. However, in a multi-level ASON hierarchy, the 568 potential volume of information could be quite large and the 569 recommendations in this section SHOULD be followed by RCs 570 implementing this specification. 572 - Routing information exchange upward/downward in the hierarchy 573 between adjacent RAs SHOULD, by default, be limited to reachability 574 information. In addition, several transformations such as prefix 575 aggregation are RECOMMENDED to reduce the amount of information 576 imported/exported by a given RC when such transformations will not 577 impact consistency. 579 - Routing information exchange upward/downward in the ASON hierarchy 580 involving TE attributes MUST be under strict policy control. 581 Pacing and min/max thresholds for triggered updates are strongly 582 RECOMMENDED. 584 - The number of routing levels MUST be maintained under strict policy 585 control. 587 9. Security Considerations 589 This document specifies the contents and processing of OSPFv2 TE LSAs 590 [RFC3630] and [RFC4202]. The TE LSA extensions defined in this 591 document are not used for SPF computation, and have no direct effect 592 on IP routing. Additionally, ASON routing domains are delimited by 593 the usual administrative domain boundaries. 595 Any mechanisms used for securing the exchange of normal OSPF LSAs can 596 be applied equally to all TE LSAs used in the ASON context. 597 Authentication of OSPFv2 LSA exchanges (such as OSPF cryptographic 598 authentication [RFC2328] and [RFC5709]) can be used to secure against 599 passive attacks and provide significant protection against active 600 attacks. [RFC5709] defines a mechanism for authenticating OSPFv2 601 packets by making use of the HMAC algorithm in conjunction with the 602 SHA family of cryptographic hash functions. 604 If a stronger authentication were believed to be required, then the 605 use of a full digital signature [RFC2154] would be an approach that 606 should be seriously considered. Use of full digital signatures would 607 enable precise authentication of the OSPF router originating each 608 OSPF link-state advertisement, and thereby provide much stronger 609 integrity protection for the OSPF routing domain. 611 10. IANA Considerations 613 This document is classified as Standards Track. It defines new sub- 614 TLVs for inclusion in OSPF TE LSAs. According to the assignment 615 policies for the registries of code points for these sub-TLVs, values 616 must be assigned by IANA [RFC3630]. 618 This draft requests early allocation of IANA code points in 619 accordance with [RFC4020]. [NOTE TO RFC Editor: this paragraph and 620 the RFC 4020 reference can be removed during RFC editing]. 622 The following subsections summarize the required sub-TLVs. 624 10.1. Sub-TLVs of the Link TLV 626 This document defines the following sub-TLVs of the Link TLV 627 advertised in the OSPF TE LSA: 629 - Local and Remote TE Router ID sub-TLV (26) 630 - Inter-RA Export Upward sub-TLV (27) 631 - Inter-RA Export Downward sub-TLV (28) 632 Codepoints for these Sub-TLVs should be allocated from the "Types for 633 sub-TLVs of TE Link TLV (Value 2)" registry standards action range (0 634 - 32767) [RFC3630]. 636 Note that the same values for the Inter-RA Export Upward sub-TLV and 637 the Inter-RA Export Downward Sub-TLV MUST be used when they appear in 638 the Link TLV, Node Attribute TLV, and Router Address TLV. 640 10.2. Sub-TLVs of the Node Attribute TLV 642 This document defines the following sub-TLVs of the Node Attribute 643 TLV advertised in the OSPF TE LSA: 645 - Local TE Router ID sub-TLV (5) 646 - Inter-RA Export Upward sub-TLV (27) 647 - Inter-RA Export Downward sub-TLV (28) 649 Codepoints for these Sub-TLVs should be assigned from the "Types for 650 sub-TLVs of TE Node Attribute TLV (Value 5)" registry standards 651 action range (0 - 32767) [RFC5786]. 653 Note that the same values for the Inter-RA Export Upward sub-TLV and 654 the Inter-RA Export Downward Sub-TLV MUST be used when they appear in 655 the Link TLV, Node Attribute TLV, and Router Address TLV. 657 10.3. Sub-TLVs of the Router Address TLV 659 The Router Address TLV is advertised in the OSPF TE LSA [RFC3630]. 660 Since this TLV currently has no Sub-TLVs defined, a "Types for sub- 661 TLVs of Router Address TLV (Value 1)" registry must be defined. 663 The registry guidelines for the assignment of types for sub-TLVs of 664 the Router Address TLV are as follows: 666 o Types in the range 0-32767 are to be assigned via Standards 667 Action. 669 o Types in the range 32768-32777 are for experimental use; these 670 will not be registered with IANA, and MUST NOT be mentioned by 671 RFCs. 673 o Types in the range 32778-65535 are not to be assigned at this 674 time. Before any assignments can be made in this range, there 675 MUST be a Standards Track RFC that specifies IANA 676 Considerations that covers the range being assigned. 678 This document defines the following sub-TLVs for inclusion in the 679 Router Address TLV: 681 - Inter-RA Export Upward sub-TLV (27) 682 - Inter-RA Export Downward sub-TLV (28) 684 Codepoints for these Sub-TLVs should be allocated from the "Types for 685 sub-TLVs of Router Address TLV (Value 1)" registry standards action 686 range (0 - 32767). 688 Note that the same values for the Inter-RA Export Upward sub-TLV and 689 the Inter-RA Export Downward Sub-TLV MUST be used when they appear in 690 the Link TLV, Node Attribute TLV, and Router Address TLV. 692 11. Management Considerations 694 11.1. Routing Area (RA) Isolation 696 If the RA Identifier is mapped to the OSPF Area ID as recommended in 697 section 2.0, OSPF [RFC2328] implicitly provides isolation. On any 698 intra-RA link, packets will only be accepted if the area-id in the 699 OSPF packet header matches the area ID for the OSPF interface on 700 which the packet was received. Hence, RCs will only establish 701 adjacencies and exchange reachability information (see Section 4.0) 702 with RCs in the same RC. Other mechanisms for RA isolation are 703 beyond the scope of this document. 705 11.2 Routing Area (RA) Topology/Configuration Changes 707 The GMPLS Routing for ASON requirements [RFC4258] dictate that the 708 routing protocol MUST support reconfiguration and SHOULD support 709 architectural evolution. OSPF [RFC2328] includes support for the 710 dynamic introduction or removal of ASON reachability information 711 through the flooding and purging of OSPF opaque LSAs [RFC5250]. Also, 712 when an RA is partitioned or an RC fails, stale LSAs SHOULD NOT be 713 used unless the advertising RC is reachable. The configuration of 714 OSPF RAs and the policies governing the redistribution of ASON 715 reachability information between RAs are implementation issues 716 outside of the OSPF routing protocol and beyond the scope of this 717 document. 719 12. Comparison to Requirements in RFC 4258 721 The following table shows how this draft complies with the 722 requirements in [RFC4258]. The first column contains a requirements 723 number (1-30) and the relevant section in RFC 4258. The second column 724 describes the requirement, the third column discusses the compliance 725 to that requirement, and the fourth column lists the relevant section 726 in draft, and/or another RFC that already satisfies the requirement. 728 +----------+---------------------------+---------------+-------------+ 729 | RFC 4258 | RFC 4258 Requirement | Compliance | Reference | 730 | Section | | | | 731 | (Req. | | | | 732 | Number) | | | | 733 +----------+---------------------------+---------------+-------------+ 734 | 3.0 (1) | The failure of an RC, or | Implied by | Not an | 735 | | the failure of | separation of |attribute of | 736 | |communications between RCs,| transport and | routing | 737 | |and the subsequent recovery|control plane. | protocol. | 738 | |from the failure condition | | | 739 | | MUST NOT disrupt call in | | | 740 | | progress. | | | 741 +----------+---------------------------+---------------+-------------+ 742 | 3.1 (2) |Multiple Hierarchical Level| Yes | Sections 2 | 743 | | of ASON Routing Areas | | and 3 | 744 | | (RAs). | | | 745 +----------+---------------------------+---------------+-------------+ 746 | 3.1 (3) | Prior to establishing | Yes when RA |Section 11.1 | 747 | | communications, RCs MUST | maps to OSPF | | 748 | |verify that they are bound | Area ID. | | 749 | | to the same parent RA. | | | 750 +----------+---------------------------+---------------+-------------+ 751 | 3.1 (4) | The RC ID MUST be unique | Yes |RFC 2328 and | 752 | | within its containing RA. | | Section 3. | 753 +----------+---------------------------+---------------+-------------+ 754 | 3.1 (5) |Each RA within a carrier's |Yes - although | Sections 2, | 755 | | network SHALL be uniquely | uniqueness is | 3, and 11.1 | 756 | |identifiable. RA IDs MAY be|the operator's | | 757 | |associated with a transport|responsibility.| | 758 | | plane name space, whereas | | | 759 | |RC IDs are associated with | | | 760 | |a control plane name space.| | | 761 +----------+---------------------------+---------------+-------------+ 762 | 3.2 (6) | Hierarchical Routing | Yes | Section 7 | 763 | | Information Dissemination | | | 764 +----------+---------------------------+---------------+-------------+ 765 | 3.2 (7) | Routing Information | Yes | Section 7.1 | 766 | |exchanged between levels N | | | 767 | | and N+1 via separate | | | 768 | | instances and | | | 769 | | import/export. | | | 770 +----------+---------------------------+---------------+-------------+ 771 +----------+---------------------------+---------------+-------------+ 772 | 3.2 (8) | Routing Information | No - Not | | 773 | |exchanged between levels N | described. | | 774 | | and N+1 via external link | | | 775 | | (inter-RA links). | | | 776 +----------+---------------------------+---------------+-------------+ 777 | 3.2 (9) | Routing information | Yes | Sections 4, | 778 | | exchange MUST include | |6, 6.1, 6.2, | 779 | | reachability information | | and 8 | 780 | | and MAY include, upon | | | 781 | | policy decision, node and | | | 782 | | link topology. | | | 783 +----------+---------------------------+---------------+-------------+ 784 | 3.2 (10) | There SHOULD NOT be any |Yes - separate | Sections 2 | 785 | | dependencies on the | instances. | and 3 | 786 | |different routing protocols| | | 787 | | used within an RA or in | | | 788 | | different RAs. | | | 789 +----------+---------------------------+---------------+-------------+ 790 | 3.2 (11) |The routing protocol SHALL | Yes | Section 7.2 | 791 | | differentiate the routing | | | 792 | |information originated at a| | | 793 | |given-level RA from derived| | | 794 | | routing information | | | 795 | | (received from external | | | 796 | | RAs), even when this | | | 797 | |information is forwarded by| | | 798 | | another RC at the same | | | 799 | | level. | | | 800 +----------+---------------------------+---------------+-------------+ 801 | 3.2 (12) | The routing protocol MUST | Yes | Section 7.2 | 802 | | provide a mechanism to | | | 803 | | prevent information | | | 804 | |propagated from a Level N+1| | | 805 | | RA's RC into the Level N | | | 806 | | RA's RC from being | | | 807 | | re-introduced into the | | | 808 | | Level N+1 RA's RC. | | | 809 +----------+---------------------------+---------------+-------------+ 810 | 3.2 (13) | The routing protocol MUST | Yes | Section 7.2 | 811 | | provide a mechanism to | | | 812 | | prevent information | | | 813 | |propagated from a Level N-1| | | 814 | | RA's RC into the Level N | | | 815 | | RA's RC from being | | | 816 | | re-introduced into the | | | 817 | | Level N-1 RA's RC. | | | 818 +----------+---------------------------+---------------+-------------+ 819 +----------+---------------------------+---------------+-------------+ 820 | 3.2 (14) | Instance of a Level N | Yes | Sections 2, | 821 | | routing function and an | | 3, and 7 | 822 | | instance of a Level N+1 | | | 823 | | routing function in the | | | 824 | | same system. | | | 825 +----------+---------------------------+---------------+-------------+ 826 | 3.2 (15) | The Level N routing | Not described | N/A | 827 | | function is on a separate | but possible. | | 828 | | system the Level N+1 | | | 829 | | routing function. | | | 830 +----------+---------------------------+---------------+-------------+ 831 | 3.3 (16) |The RC MUST support static | Yes - | Sections 2 | 832 | | (i.e., operator assisted) | automation |and 3. Config| 833 | | and MAY support automated |requirement is | is product | 834 | | configuration of the | ambiguous. | specific. | 835 | |information describing its | | | 836 | |relationship to its parent | | | 837 | | and its child within the | | | 838 | | hierarchical structure | | | 839 | | (including RA ID and RC | | | 840 | | ID). | | | 841 +----------+---------------------------+---------------+-------------+ 842 | 3.3 (17) |The RC MUST support static |Yes - when OSPF|RFC 2328 and | 843 | | (i.e., operator assisted) |area maps to RA|Section 11.1 | 844 | | and MAY support automated | discovery is | | 845 | | configuration of the | automatic. | | 846 | |information describing its | | | 847 | | associated adjacencies to | | | 848 | | other RCs within an RA. | | | 849 +----------+---------------------------+---------------+-------------+ 850 | 3.3 (18) |The routing protocol SHOULD| Yes | RFC 2328 | 851 | |support all the types of RC| | | 852 | | adjacencies described in | | | 853 | |Section 9 of [G.7715]. The | | | 854 | | latter includes congruent | | | 855 | |topology (with distributed | | | 856 | | RC) and hubbed topology | | | 857 | |(e.g., note that the latter| | | 858 | | does not automatically | | | 859 | | imply a designated RC). | | | 860 +----------+---------------------------+---------------+-------------+ 861 +----------+---------------------------+---------------+-------------+ 862 | 3.4 (19) |The routing protocol SHOULD| Yes |RFC 2328, RFC| 863 | | be capable of supporting | | 5250, and | 864 | |architectural evolution in | |Section 11.2.| 865 | | terms of the number of | | | 866 | |hierarchical levels of RAs,| | | 867 | |as well as the aggregation | | | 868 | | and segmentation of RAs. | | | 869 +----------+---------------------------+---------------+-------------+ 870 |3.5.2 (20)|Advertisements MAY contain | | | 871 | |the following common set of| | | 872 | | information regardless of | | | 873 | | whether they are link or | | | 874 | | node related: | | | 875 | | - RA ID of the RA to | Yes |Section 7.2.1| 876 | |which the advertisement is | | | 877 | | bounded | | | 878 | | - RC ID of the entity | Yes | RFC 2328 | 879 | | generating the | | | 880 | | advertisement | | | 881 | | - Information to | Yes |RFC 2328, RFC| 882 | | uniquely identify | | 5250 | 883 | | advertisements | | | 884 | | - Information to | No - Must | | 885 | | determine whether an |compare to old | | 886 | | advertisement has been | | | 887 | | updated | | | 888 | | - Information to | Yes |Section 7.2.1| 889 | | indicate when an | | | 890 | | advertisement has been | | | 891 | | derived from a different | | | 892 | | level RA | | | 893 +----------+---------------------------+---------------+-------------+ 894 |3.5.3 (21)|The Node Attributes Node ID|Yes - Prefixes | RFC 5786, | 895 | | and Reachability must be | only for |Section 4 and| 896 | | advertised. It MAY be | reachability | 6 | 897 | | advertised as a set of | | | 898 | |associated external (e.g., | | | 899 | | User Network Interface | | | 900 | | (UNI)) address/address | | | 901 | | prefixes or a set of | | | 902 | | associated SNPP link | | | 903 | | IDs/SNPP ID prefixes, the | | | 904 | |selection of which MUST be | | | 905 | | consistent within the | | | 906 | | applicable scope. | | | 907 +----------+---------------------------+---------------+-------------+ 908 +----------+---------------------------+---------------+-------------+ 909 |3.5.4 (22)| The Link Attributes Local | Yes | Section 6.1 | 910 | | SNPP link ID, Remote SNPP | | | 911 | |link ID, and layer specific| | | 912 | | characteristics must be | | | 913 | | advertised. | | | 914 +----------+---------------------------+---------------+-------------+ 915 |3.5.4 (23)| Link Signaling Attributes | Yes | Section 5, | 916 | |other than Local Adaptation| | RFC 4652 - | 917 | |(Signal Type, Link Weight, | |Section 5.3.1| 918 | | Resource Class, Local | | | 919 | | Connection Types, Link | | | 920 | | Capacity, Link | | | 921 | | Availability, Diversity | | | 922 | | Support) | | | 923 +----------+---------------------------+---------------+-------------+ 924 |3.5.4 (24)| Link Signaling Local | Yes | Section 5.1 | 925 | | Adaptation | | | 926 +----------+---------------------------+---------------+-------------+ 927 | 5 (25) | The routing adjacency | Yes |Section 2, 3,| 928 | | topology (i.e., the | | and 6 | 929 | |associated PC connectivity | | | 930 | |topology) and the transport| | | 931 | |network topology SHALL NOT | | | 932 | |be assumed to be congruent.| | | 933 +----------+---------------------------+---------------+-------------+ 934 | 5 (26) |The routing topology SHALL | Yes |RFC 2328, RFC| 935 | | support multiple links | | 3630 | 936 | | between nodes and RAs. | | | 937 +----------+---------------------------+---------------+-------------+ 938 | 5 (27) |The routing protocol SHALL | Yes |RFC 2328, RFC| 939 | | converge such that the | | 5250 | 940 | | distributed RDBs become | | | 941 | |synchronized after a period| | | 942 | | of time. | | | 943 +----------+---------------------------+---------------+-------------+ 944 | 5 (28) |Self-consistent information|Yes - However, | Section 7.1 | 945 | | at the receiving level | this is not a | | 946 | | resulting from any | routing | | 947 | | transformation (filter, | protocol | | 948 | | summarize, etc.) and | function. | | 949 | | forwarding of information | | | 950 | | from one RC to RC(s) at | | | 951 | | different levels when | | | 952 | |multiple RCs are bound to a| | | 953 | | single RA. | | | 954 +----------+---------------------------+---------------+-------------+ 955 +----------+---------------------------+---------------+-------------+ 956 | 5 (29) | In order to support |Partial - OSPF |RFC 2328 and | 957 | | operator-assisted changes | supports the | RFC 5250 | 958 | | in the containment | purging of | | 959 | | relationships of RAs, the | stale | | 960 | | routing protocol SHALL |advertisements | | 961 | |support evolution in terms |and origination| | 962 | | of the number of | of new. The | | 963 | |hierarchical levels of RAs.|non-disruptive | | 964 | | For example: support of | behavior is | | 965 | | non-disruptive operations |implementation | | 966 | |such as adding and removing| specific. | | 967 | | RAs at the top/bottom of | | | 968 | | the hierarchy, adding or | | | 969 | | removing a hierarchical | | | 970 | |level of RAs in or from the| | | 971 | |middle of the hierarchy, as| | | 972 | | well as aggregation and | | | 973 | | segmentation of RAs. | | | 974 +----------+---------------------------+---------------+-------------+ 975 | 5 (30) | A collection of links and |Yes - Within an| Sections 4 | 976 | |nodes such as a subnetwork | RA it must be | and 6 | 977 | | or RA MUST be able to | consistent. | | 978 | | represent itself to the | | | 979 | | wider network as a single | | | 980 | | logical entity with only | | | 981 | |its external links visible | | | 982 | | to the topology database. | | | 983 +----------+---------------------------+---------------+-------------+ 985 13. References 987 13.1. Normative References 989 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 990 Requirement Levels", BCP 14, RFC 2119, March 1997. 992 [RFC2328] Moy, J., "OSPF Version 2", STD 54, RFC 2328, April 1998. 994 [RFC3630] Katz, D., Kompella, K., and D. Yeung, "Traffic 995 Engineering (TE) Extensions to OSPF Version 2", RFC 996 3630, September 2003. 998 [RFC3945] Mannie, E., Ed., "Generalized Multi-Protocol Label 999 Switching (GMPLS) Architecture", RFC 3945, October 2004. 1001 [RFC4202] Kompella, K., Ed., and Y. Rekhter, Ed., "Routing 1002 Extensions in Support of Generalized Multi-Protocol 1003 Label Switching (GMPLS)", RFC 4202, October 2005. 1005 [RFC4203] Kompella, K., Ed., and Y. Rekhter, Ed., "OSPF Extensions 1006 in Support of Generalized Multi-Protocol Label Switching 1007 (GMPLS)", RFC 4203, October 2005. 1009 [RFC5250] Berger, L., Bryskin, I., Zinin, A., and R. Coltun, "The 1010 OSPF Opaque LSA Option", RFC 5250, July 2008. 1012 [RFC5786] Aggarwal, R. and K. Kompella, "Advertising a Router's 1013 Local Addresses in OSPF TE Extensions", RFC 5786, March 1014 2010. 1016 13.2. Informative References 1018 [RFC2154] Murphy, S., Badger, M., and B. Wellington, "OSPF with 1019 Digital Signatures", RFC 2154, June 1997. 1021 [RFC4020] Kompella, K. and A. Zinin, "Early IANA Allocation of 1022 Standards Track Code Points", BCP 100, RFC 4020, 1023 February 2005. 1025 [RFC4258] Brungard, D., Ed., "Requirements for Generalized Multi- 1026 Protocol Label Switching (GMPLS) Routing for the 1027 Automatically Switched Optical Network (ASON)", RFC 1028 4258, November 2005. 1030 [RFC4652] Papadimitriou, D., Ed., Ong, L., Sadler, J., Shew, S., 1031 and D. Ward, "Evaluation of Existing Routing Protocols 1032 against Automatic Switched Optical Network (ASON) 1033 Routing Requirements", RFC 4652, October 2006. 1035 [RFC5709] Bhatia, M., Manral, V., Fanto, M., White, R., Barnes, 1036 M., Li, T., and R. Atkinson, "OSPFv2 HMAC-SHA 1037 Cryptographic Authentication", RFC 5709, October 2009. 1039 For information on the availability of ITU Documents, please see 1040 http://www.itu.int. 1042 [G.7715] ITU-T Rec. G.7715/Y.1306, "Architecture and Requirements 1043 for the Automatically Switched Optical Network (ASON)", 1044 June 2002. 1046 [G.7715.1] ITU-T Rec. G.7715.1/Y.1706.1, "ASON Routing Architecture 1047 and Requirements for Link State Protocols", February 1048 2004. 1050 [G.805] ITU-T Rec. G.805, "Generic Functional Architecture of 1051 Transport Networks)", March 2000. 1053 [G.8080] ITU-T Rec. G.8080/Y.1304, "Architecture for the 1054 Automatically Switched Optical Network (ASON)," June 1055 2006 (and Amendments 1 (March 2008) and 2 (Sept. 2010)). 1057 14. Acknowledgements 1059 The editors would like to thank Lyndon Ong, Remi Theillaud, Stephen 1060 Shew, Jonathan Sadler, Deborah Brungard, and Lou Berger for their 1061 useful comments and suggestions. 1063 Appendix A. ASON Terminology 1065 This document makes use of the following terms: 1067 Administrative domain: (See Recommendation [G.805].) For the 1068 purposes of [G7715.1], an administrative domain represents the 1069 extent of resources that belong to a single player such as a 1070 network operator, a service provider, or an end-user. 1071 Administrative domains of different players do not overlap amongst 1072 themselves. 1074 Control plane: performs the call control and connection control 1075 functions. Through signaling, the control plane sets up and 1076 releases connections, and may restore a connection in case of a 1077 failure. 1079 (Control) Domain: represents a collection of (control) entities that 1080 are grouped for a particular purpose. The control plane is 1081 subdivided into domains matching administrative domains. Within 1082 an administrative domain, further subdivisions of the control 1083 plane are recursively applied. A routing control domain is an 1084 abstract entity that hides the details of the RC distribution. 1086 External NNI (E-NNI): interfaces located between protocol controllers 1087 between control domains. 1089 Internal NNI (I-NNI): interfaces located between protocol controllers 1090 within control domains. 1092 Link: (See Recommendation G.805.) A "topological component" that 1093 describes a fixed relationship between a "subnetwork" or "access 1094 group" and another "subnetwork" or "access group". Links are not 1095 limited to being provided by a single server trail. 1097 Management plane: performs management functions for the transport 1098 plane, the control plane, and the system as a whole. It also 1099 provides coordination between all the planes. The following 1100 management functional areas are performed in the management plane: 1101 performance, fault, configuration, accounting, and security 1102 management. 1104 Management domain: (See Recommendation G.805.) A management domain 1105 defines a collection of managed objects that are grouped to meet 1106 organizational requirements according to geography, technology, 1107 policy, or other structure, and for a number of functional areas 1108 such as configuration, security, (FCAPS), for the purpose of 1109 providing control in a consistent manner. Management domains can 1110 be disjoint, contained, or overlapping. As such, the resources 1111 within an administrative domain can be distributed into several 1112 possible overlapping management domains. The same resource can 1113 therefore 1114 belong to several management domains simultaneously, but a 1115 management domain shall not cross the border of an administrative 1116 domain. 1118 Subnetwork Point (SNP): The SNP is a control plane abstraction that 1119 represents an actual or potential transport plane resource. SNPs 1120 (in different subnetwork partitions) may represent the same 1121 transport resource. A one-to-one correspondence should not be 1122 assumed. 1124 Subnetwork Point Pool (SNPP): A set of SNPs that are grouped together 1125 for the purposes of routing. 1127 Termination Connection Point (TCP): A TCP represents the output of a 1128 Trail Termination function or the input to a Trail Termination 1129 Sink function. 1131 Transport plane: provides bidirectional or unidirectional transfer of 1132 user information, from one location to another. It can also 1133 provide transfer of some control and network management 1134 information. The transport plane is layered; it is equivalent to 1135 the Transport Network defined in Recommendation G.805. 1137 User Network Interface (UNI): interfaces are located between protocol 1138 controllers between a user and a control domain. Note: There is 1139 no routing function associated with a UNI reference point. 1141 Appendix B. ASON Routing Terminology 1143 This document makes use of the following terms: 1145 Routing Area (RA): an RA represents a partition of the data plane, 1146 and its identifier is used within the control plane as the 1147 representation of this partition. Per [G.8080], an RA is defined 1148 by a set of sub-networks, the links that interconnect them, and 1149 the interfaces representing the ends of the links exiting that RA. 1150 An RA may contain smaller RAs inter-connected by links. The 1151 limit of subdivision results in an RA that contains two sub- 1152 networks interconnected by a single link. 1154 Routing Database (RDB): a repository for the local topology, network 1155 topology, reachability, and other routing information that is 1156 updated as part of the routing information exchange and may 1157 additionally contain information that is configured. The RDB may 1158 contain routing information for more than one routing area (RA). 1160 Routing Components: ASON routing architecture functions. These 1161 functions can be classified as protocol independent (Link Resource 1162 Manager or LRM, Routing Controller or RC) or protocol specific 1163 (Protocol Controller or PC). 1165 Routing Controller (RC): handles (abstract) information needed for 1166 routing and the routing information exchange with peering RCs by 1167 operating on the RDB. The RC has access to a view of the RDB. 1168 The RC is protocol independent. 1170 Note: Since the RDB may contain routing information pertaining to 1171 multiple RAs (and possibly to multiple layer networks), the RCs 1172 accessing the RDB may share the routing information. 1174 Link Resource Manager (LRM): supplies all the relevant component and 1175 TE link information to the RC. It informs the RC about any state 1176 changes of the link resources it controls. 1178 Protocol Controller (PC): handles protocol-specific message exchanges 1179 according to the reference point over which the information is 1180 exchanged (e.g., E-NNI, I-NNI), and internal exchanges with the 1181 RC. The PC function is protocol dependent. 1183 Authors' Addresses 1185 Andrew G. Malis 1186 Verizon Communications 1187 117 West St. 1188 Waltham MA 02451 USA 1190 EMail: andrew.g.malis@verizon.com 1192 Acee Lindem 1193 Ericsson 1194 102 Carric Bend Court 1195 Cary, NC 27519 1197 EMail: acee.lindem@ericsson.com 1199 Dimitri Papadimitriou 1200 Alcatel-Lucent 1201 Copernicuslaan, 50 1202 2018 Antwerpen, Belgium 1204 EMail: dimitri.papadimitriou@alcatel-lucent.com