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'2') == Outdated reference: A later version (-05) exists of draft-ietf-isis-traffic-00 ** Downref: Normative reference to an Informational draft: draft-ietf-isis-traffic (ref. '3') ** Obsolete normative reference: RFC 2370 (ref. '4') (Obsoleted by RFC 5250) Summary: 7 errors (**), 0 flaws (~~), 4 warnings (==), 2 comments (--). Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 1 Network Working Group Dave Katz 2 Internet Draft Juniper Networks, Inc. 3 Expiration Date: April 2000 Derek Yeung 4 TBD 6 Traffic Engineering Extensions to OSPF 8 draft-katz-yeung-ospf-traffic-01.txt 10 Status 12 This document is an Internet-Draft and is in full conformance with 13 all provisions of Section 10 of RFC2026. 15 Internet-Drafts are working documents of the Internet Engineering 16 Task Force (IETF), its areas, and its working groups. Note that 17 other groups may also distribute working documents as Internet- 18 Drafts. 20 Internet-Drafts are draft documents valid for a maximum of six months 21 and may be updated, replaced, or obsoleted by other documents at any 22 time. It is inappropriate to use Internet- Drafts as reference 23 material or to cite them other than as "work in progress." 25 The list of current Internet-Drafts can be accessed at 26 http://www.ietf.org/ietf/1id-abstracts.txt 28 The list of Internet-Draft Shadow Directories can be accessed at 29 http://www.ietf.org/shadow.html. 31 Abstract 33 This document describes extensions to the OSPF protocol to support 34 Traffic Engineering, using opaque LSAs. 36 1. Introduction 38 This document specifies a method of adding traffic engineering 39 capabilities to OSPF [1]. The architecture of traffic engineering is 40 described in [2]. The semantic content of the extensions is 41 essentially identical to the corresponding extensions to IS-IS [3]. 42 It is expected that the traffic engineering extensions to OSPF will 43 continue to mirror those in IS-IS. 45 The extensions provide a way of describing the traffic engineering 46 topology (including bandwidth and administrative constraints). This 47 topology does not necessarily match the regular routed topology, 48 though this proposal depends on Network LSAs to describe multiaccess 49 links. 51 2. LSA Format 53 2.1 LSA type 55 This extension makes use of the Opaque LSA [4]. 57 Three types of Opaque LSAs exist, each of which has different 58 flooding scope. This proposal uses only Type 10 LSAs, which have 59 area flooding scope. 61 One new LSA is defined, the Traffic Engineering LSA. This LSA 62 describes routers, point-to-point links, and connections to 63 multiaccess networks (similar to a Router LSA). For traffic 64 engineering purposes, the existing Network LSA suffices for 65 describing multiaccess links, so no additional LSA is defined for 66 this purpose. 68 2.2 LSA ID 70 The LSA ID of an Opaque LSA is defined as having eight bits of type 71 and 24 bits of type-specific data. The Traffic Engineering LSA uses 72 type 1. The remaining 24 bits are broken up into eight bits of 73 reserved space (which must be zero) and sixteen bits of instance: 75 0 1 2 3 76 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 77 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 78 | 1 | Reserved | Instance | 79 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 81 The Instance field is an arbitrary value used to maintain multiple 82 Traffic Engineering LSAs. A maximum of 65536 Traffic Engineering 83 LSAs may be sourced by a single system. The LSA ID has no 84 topological significance. 86 2.3 LSA Format Overview 88 2.3.1 LSA Header 90 The Traffic Engineering LSA starts with the standard LSA header: 92 0 1 2 3 93 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 94 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 95 | LS age | Options | 10 | 96 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 97 | TBD | Reserved | Instance | 98 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 99 | Advertising Router | 100 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 101 | LS sequence number | 102 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 103 | LS checksum | length | 104 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 106 2.3.2 TLV Header 108 The LSA payload consists of one or more nested Type/Length/Value 109 (TLV) triplets for extensibility. The format of each TLV is: 111 0 1 2 3 112 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 1 113 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 114 | Type | length | 115 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 116 | Value... | 117 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 119 The length field defines the length of the value portion in bytes 120 (thus a TLV with no value portion would have a length of zero). The 121 TLV is padded to four-byte alignment; padding is not included in the 122 length field (so a three byte value would have a length of three, but 123 the total size of the TLV would be eight bytes). Nested TLVs are 124 also 32-bit aligned. Unrecognized types are ignored. All types 125 between 32768 and 65535 are reserved for vendor-specific extensions. 126 All other undefined type codes are reserved for future assignment by 127 IANA. 129 2.4 LSA payload details 131 An LSA contains one top-level TLV. 133 There are two top-level TLVs defined: 135 1 - Router Address 136 2 - Link 138 2.4.1 Router Address TLV 140 The Router Address TLV specifies a stable IP address of the 141 advertising router that is always reachable if there is any 142 connectivity to it. This is typically implemented as a "loopback 143 address"; the key attribute is that the address does not become 144 unusable if an interface is down. In other protocols this is known 145 as the "router ID," but for obvious reasons this nomenclature is 146 avoided here. 148 The router address TLV is type 1, and has a length of 4, and the 149 value is the four octet IP address. It must appear in exactly one 150 Traffic Engineering LSA originated by a router. 152 2.4.2 Link TLV 154 The Link TLV describes a single link. It is constructed of a set of 155 sub-TLVs. There are no ordering requirements for the sub-TLVs. 157 Only one Link TLV shall be carried in each LSA, allowing for fine 158 granularity changes in topology. 160 Only numbered links are described, as traffic engineering is not 161 supported on unnumbered links. 163 The Link TLV is type 2, and the length is variable. 165 The following sub-TLVs are defined: 167 1 - Link type (1 octet) 168 2 - Link ID (4 octets) 169 3 - Local interface IP address (4 octets) 170 4 - Remote interface IP address (4 octets) 171 5 - Traffic engineering metric (4 octets) 172 6 - Maximum bandwidth (4 octets) 173 7 - Maximum reservable bandwidth (4 octets) 174 8 - Unreserved bandwidth (32 octets) 175 9 - Resource class/color (4 octets) 177 32768-32772 - Reserved for Cisco-specific extensions 179 Each sub-TLV may occur only once. Unrecognized types are ignored. 180 All of the defined sub-TLVs are mandatory (though future sub-TLVs may 181 not necessarily be mandatory.) 183 2.5 Sub-TLV Details 185 2.5.1 Link Type 187 The Link Type sub-TLV defines the type of the link: 189 1 - Point-to-point 190 2 - Multiaccess 192 The Link Type sub-TLV is TLV type 1, and is one octet in length. 194 2.5.2 Link ID 196 The Link ID sub-TLV identifies the other end of the link. For point- 197 to-point links, this is the Router ID of the neighbor. For 198 multiaccess links, this is the interface address of the designated 199 router. The Link ID is identical to the contents of the Link ID 200 field in the Router LSA for these link types. 202 The Link ID sub-TLV is TLV type 2, and is four octets in length. 204 2.5.3 Local Interface IP Address 206 The Local Interface IP Address sub-TLV specifies the IP address of 207 the interface corresponding to this link. Note that at the moment, 208 only numbered point-to-point links are supported for traffic 209 engineering. 211 The Local Interface IP Address sub-TLV is TLV type 3, and is four 212 octets in length. 214 2.5.4 Remote Interface IP Address 216 The Remote Interface IP Address sub-TLV specifies the IP address of 217 the neighbor's interface corresponding to this link. This and the 218 local address are used to discern multiple parallel links between 219 systems. 221 The Remote Interface IP Address sub-TLV is TLV type 4, and is four 222 octets in length. 224 2.5.5 Traffic Engineering Metric 226 The Traffic Engineering Metric sub-TLV specifies the link metric for 227 traffic engineering purposes. This metric may be different than the 228 standard OSPF link metric. 230 The Traffic Engineering Metric sub-TLV is TLV type 5, and is four 231 octets in length. 233 2.5.6 Maximum Bandwidth 235 The Maximum Bandwidth sub-TLV specifies the maximum bandwidth that 236 can be used on this link in this direction (from the system 237 originating the LSA to its neighbor), in IEEE floating point format. 238 This is the true link capacity. The units are *bytes* per second. 240 The Maximum Bandwidth sub-TLV is TLV type 6, and is four octets in 241 length. 243 2.5.7 Maximum Reservable Bandwidth 245 The Maximum Reservable Bandwidth sub-TLV specifies the maximum 246 bandwidth that may be reserved on this link in this direction, in 247 IEEE floating point format. Note that this may be greater than the 248 maximum bandwidth (in which case the link may be oversubscribed). 249 The units are bytes per second. 251 The Maximum Reservable Bandwidth sub-TLV is TLV type 7, and is four 252 octets in length. 254 2.5.8 Unreserved Bandwidth 256 The Unreserved Bandwidth sub-TLV specifies the amount of bandwidth 257 not yet reserved at each of the eight priority levels, in IEEE 258 floating point format. Each value will be less than or equal to the 259 maximum reservable bandwidth. The units are bytes per second. 261 The Unreserved Bandwidth sub-TLV is TLV type 8, and is 32 octets in 262 length. 264 2.5.9 Resource Class/Color 266 The Resource Class/Color sub-TLV specifies administrative group 267 membership for this link, in terms of a bit mask. A link that is a 268 member of multiple groups will have multiple bits set. 270 The Resource Class/Color sub-TLV is TLV type 9, and is four octets in 271 length. 273 3. Elements of Procedure 275 Routers shall originate Traffic Engineering LSAs whenever the LSA 276 contents change, and whenever otherwise required by OSPF (an LSA 277 refresh, for example). 279 Upon receipt of a changed Traffic Engineering LSA or Network LSA 280 (since these are used in traffic engineering calculations), the 281 router should update its traffic engineering database. No SPF or 282 other route calculations are necessary. 284 4. Compatibility Issues 286 There should be no interoperability issues with routers that do not 287 implement these extensions, as the Opaque LSAs will be silently 288 ignored. 290 The result of having routers that do not implement these extensions 291 is that the traffic engineering topology will be missing pieces; 292 however, if the topology is connected, TE paths can still be 293 calculated and ought to work. 295 5. Security Considerations 297 This document raises no new security issues for OSPF. 299 6. References 301 [1] Moy, J., "OSPF Version 2", RFC 2328, April 1998. 303 [2] Awduche, D., et al, "Requirements for Traffic Engineering Over 304 MPLS," draft-ietf-mpls-traffic-eng-00.txt, work in progress. 306 [3] Smit, H. and T. Li, "ISIS Extensions for Traffic Engineering," 307 draft-ietf-isis-traffic-00.txt, work in progress. 309 [4] Coltun, R., "The OSPF Opaque LSA Option," RFC 2370, July 1998. 311 7. Authors' Addresses 313 Dave Katz 314 Juniper Networks 315 385 Ravendale Drive 316 Mountain View, CA 94043 USA 318 Phone: +1 650 526 8073 319 Email: dkatz@juniper.net 321 Derek M. Yeung 322 TBD