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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) == Missing Reference: 'This ID' is mentioned on line 287, but not defined Summary: 0 errors (**), 0 flaws (~~), 2 warnings (==), 1 comment (--). Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 1 Network Working Group H. Long, M. Ye 2 Internet Draft Huawei Technologies Co., Ltd 3 Intended status: Standards Track G. Mirsky 4 ZTE 5 A.D'Alessandro 6 Telecom Italia S.p.A 7 H. Shah 8 Ciena 9 Expires: July 2019 January 2, 2019 11 Ethernet Traffic Parameters with Availability Information 12 draft-ietf-ccamp-rsvp-te-bandwidth-availability-12.txt 14 Abstract 16 A packet switching network may contain links with variable bandwidth, 17 e.g., copper, radio, etc. The bandwidth of such links is sensitive 18 to external environment. Availability is typically used for 19 describing the link during network planning. This document 20 introduces an optional Availability TLV in Resource ReSerVation 21 Protocol - Traffic Engineer (RSVP-TE) signaling. This extension can 22 be used to set up a Generalized Multi-Protocol Label Switching 23 (GMPLS) Label Switched Path (LSP) using the Ethernet SENDER_TSPEC 24 object. 26 Status of this Memo 28 This Internet-Draft is submitted in full conformance with the 29 provisions of BCP 78 and BCP 79. 31 Internet-Drafts are working documents of the Internet Engineering 32 Task Force (IETF), its areas, and its working groups. Note that 33 other groups may also distribute working documents as Internet- 34 Drafts. 36 Internet-Drafts are draft documents valid for a maximum of six 37 months and may be updated, replaced, or obsoleted by other documents 38 at any time. It is inappropriate to use Internet-Drafts as 39 reference material or to cite them other than as "work in progress." 41 The list of current Internet-Drafts can be accessed at 42 http://www.ietf.org/ietf/1id-abstracts.txt 44 The list of Internet-Draft Shadow Directories can be accessed at 45 http://www.ietf.org/shadow.html 46 This Internet-Draft will expire on July 2, 2019. 48 Copyright Notice 50 Copyright (c) 2019 IETF Trust and the persons identified as the 51 document authors. All rights reserved. 53 This document is subject to BCP 78 and the IETF Trust's Legal 54 Provisions Relating to IETF Documents 55 (http://trustee.ietf.org/license-info) in effect on the date of 56 publication of this document. Please review these documents 57 carefully, as they describe your rights and restrictions with 58 respect to this document. Code Components extracted from this 59 document must include Simplified BSD License text as described in 60 Section 4.e of the Trust Legal Provisions and are provided without 61 warranty as described in the Simplified BSD License. 63 Table of Contents 65 1. Introduction ................................................ 3 66 2. Overview .................................................... 4 67 3. Extension to RSVP-TE Signaling............................... 4 68 3.1. Availability TLV........................................ 4 69 3.2. Signaling Process....................................... 5 70 4. Security Considerations...................................... 6 71 5. IANA Considerations ......................................... 6 72 5.1 Ethernet Sender TSpec TLVs ............................. 6 73 6. References .................................................. 7 74 6.1. Normative References.................................... 7 75 6.2. Informative References.................................. 7 76 7. Appendix: Bandwidth Availability Example..................... 8 77 8. Acknowledgments ............................................. 9 79 Conventions used in this document 81 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 82 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this 83 document are to be interpreted as described in RFC-2119 [RFC2119]. 85 The following acronyms are used in this draft: 87 RSVP-TE Resource Reservation Protocol-Traffic Engineering 89 LSP Label Switched Path 91 SNR Signal-to-noise Ratio 92 TLV Type Length Value 94 LSA Link State Advertisement 96 1. Introduction 98 The RSVP-TE specification [RFC3209] and GMPLS extensions [RFC3473] 99 specify the signaling message including the bandwidth request for 100 setting up a Label Switched Path in a packet switching network. 102 Some data communication technologies allow seamless change of 103 maximum physical bandwidth through a set of known discrete values. 104 The parameter availability [G.827], [F.1703], [P.530] is often used 105 to describe the link capacity during network planning. The 106 availability is a time scale, which is a proportion of the operating 107 time that the requested bandwidth is ensured. A more detailed 108 example on the bandwidth availability can be found in Appendix A. 109 Assigning different bandwidth availability classes to different 110 types of service over such kind of links provides more efficient 111 planning of link capacity. To set up an LSP across these links, 112 bandwidth availability information is required for the nodes to 113 verify bandwidth satisfaction and make bandwidth reservation. The 114 bandwidth availability information should be inherited from the 115 bandwidth availability requirements of the services expected to be 116 carried on the LSP. For example, voice service usually needs "five 117 nines" bandwidth availability, while non-real time services may 118 adequately perform at four or three nines bandwidth availability. 119 Since different service types may need different availabilities 120 guarantees, multiple pairs may be required 121 when signaling. 123 If the bandwidth availability requirement is not specified in the 124 signaling message, the bandwidth will be reserved as the highest 125 bandwidth availability. For example, the bandwidth with 99.999% 126 availability of a link is 100 Mbps; the bandwidth with 99.99% 127 availability is 200 Mbps. When a video application requests for 120 128 Mbps without bandwidth availability requirement, the system will 129 consider the request as 120 Mbps with 99.999% bandwidth availability, 130 while the available bandwidth with 99.999% bandwidth availability is 131 only 100 Mbps, therefore the LSP path cannot be set up. But in fact, 132 video application doesn't need 99.999% bandwidth availability; 99.99% 133 bandwidth availability is enough. In this case, the LSP could be set 134 up if bandwidth availability is specified in the signaling message. 136 To fulfill LSP setup by signaling in these scenarios, this document 137 specifies an Availability TLV. The Availability TLV can be 138 applicable to any kind of physical links with variable discrete 139 bandwidth, such as microwave or DSL. Multiple Availability TLVs 140 together with multiple Ethernet Bandwidth Profiles can be carried by 141 the Ethernet SENDER_TSPEC object [RFC6003]. Since the Ethernet 142 FLOWSPEC object has the same format as the Ethernet SENDER_TSPEC 143 object [RFC6003], the Availability TLV can also be carried by the 144 Ethernet FLOWSPEC object. 146 2. Overview 148 A tunnel in a packet switching network may span one or more links in 149 a network. To setup a Label Switched Path (LSP), a node may collect 150 link information which is spread in routing message, e.g., OSPF TE 151 LSA message, by network nodes to get to know about the network 152 topology, and calculate out an LSP route based on the network 153 topology, and send the calculated LSP route to signaling to initiate 154 a PATH/RESV message for setting up the LSP. 156 In case that there is (are) link(s) with variable discrete bandwidth 157 in a network, a requirement list should be 158 specified for an LSP. Each pair in the 159 list means that listed bandwidth with specified availability is 160 required. The list could be inherited from the results of service 161 planning for the LSP. 163 A node which has link(s) with variable discrete bandwidth attached 164 should contain a information list in its 165 OSPF TE LSA messages. The list provides the mapping between the link 166 nominal bandwidth and its availability level. This information is 167 used for path calculation by the node(s). The routing extension for 168 availability can be found in [RFC8330]. 170 When a node initiates a PATH/RESV signaling to set up an LSP, the 171 PATH message should carry the requirement 172 list as bandwidth request. Intermediate node(s) will allocate the 173 bandwidth resource for each availability requirement from the 174 remaining bandwidth with corresponding availability. An error 175 message may be returned if any request 176 cannot be satisfied. 178 3. Extension to RSVP-TE Signaling 180 3.1. Availability TLV 182 An Availability TLV is defined as a TLV of the Ethernet SENDER_TSPEC 183 object [RFC6003] in this document. The Ethernet SENDER_TSPEC object 184 MAY include more than one Availability TLV. The Availability TLV has 185 the following format: 187 0 1 2 3 188 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 1 189 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 190 | Index | Reserved | 191 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 192 | Availability | 193 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 195 Figure 1: Availability TLV 197 Index (1 octet): 199 When the Availability TLV is included, it MUST be present along 200 with the Ethernet Bandwidth Profile TLV. If the bandwidth 201 requirements in the multiple Ethernet Bandwidth Profile TLVs have 202 different Availability requirements, multiple Availability TLVs 203 SHOULD be carried. In such a case, the Availability TLV has one to 204 one correspondence with Ethernet Bandwidth Profile TLV by having 205 the same value of Index field. If all the bandwidth requirements 206 in the Ethernet Bandwidth Profile have the same Availability 207 requirement, one Availability TLV SHOULD be carried. In this case, 208 the Index field is set to 0. 210 Reserved (3 octets): These bits SHOULD be set to zero when sent 211 and MUST be ignored when received. 213 Availability (4 octets): a 32-bit floating number describes the 214 decimal value of availability requirement for this bandwidth 215 request. The value MUST be less than 1and is usually expressed in 216 the value of 0.99/0.999/0.9999/0.99999. 218 3.2. Signaling Process 220 The source node initiates a PATH message which may carry a number of 221 bandwidth request information, including one or more Ethernet 222 Bandwidth Profile TLVs and one or more Availability TLVs. Each 223 Ethernet Bandwidth Profile TLV corresponds to an availability 224 parameter in the Availability TLV. 226 The intermediate and destination nodes check whether they can 227 satisfy the bandwidth requirements by comparing each bandwidth 228 requirement inside the SENDER_TSPEC objects with the remaining link 229 sub-bandwidth resource with respective availability guarantee on the 230 local link when the PATH message is received. 232 o When all requirements can be 233 satisfied (the requested bandwidth under each availability 234 parameter is smaller than or equal to the remaining bandwidth 235 under the corresponding availability parameter on its local 236 link), it SHOULD reserve the bandwidth resource from each 237 remaining sub-bandwidth portion on its local link to set up 238 this LSP. Optionally, the higher availability bandwidth can be 239 allocated to lower availability request when the lower 240 availability bandwidth cannot satisfy the request. 242 o When at least one requirement 243 cannot be satisfied, it SHOULD generate PathErr message with 244 the error code "Admission Control Error" and the error value 245 "Requested Bandwidth Unavailable" (see [RFC2205]). 247 When two LSPs request bandwidth with the same availability 248 requirement, contention MUST be resolved by comparing the node IDs, 249 with the LSP with the higher node ID being assigned the reservation. 250 This is consistent with general contention resolution mechanism 251 provided in section 3.2 of [RFC3473]. 253 When a node does not support Availability TLV, it SHOULD generate 254 PathErr message with the error code "Extended Class-Type Error" and 255 the error value "Class-Type mismatch" (see [RFC2205]). 257 4. Security Considerations 259 This document does not introduce new security considerations to the 260 existing RSVP-TE signaling protocol. [RFC5920] provides an overview 261 of security vulnerabilities and protection mechanisms for the GMPLS 262 control plane. 264 5. IANA Considerations 266 IANA maintains registries and sub-registries for RSVP-TE used by 267 GMPLS. IANA is requested to make allocations from these registries 268 as set out in the following sections. 270 5.1 Ethernet Sender TSpec TLVs 272 IANA maintains a registry of GMPLS parameters called "Generalized 273 Multi-Protocol Label Switching (GMPLS) Signaling Parameters". 275 IANA has created a sub-registry called "Ethernet Sender TSpec TLVs / 276 Ethernet Flowspec TLVs" to contain the TLV type values for TLVs 277 carried in the Ethernet SENDER_TSPEC object. The sub-registry is 278 needed to be updated to include the Availability TLV which is 279 defined as follow. This document proposes a suggested value for the 280 Availability sub-TLV; it is recommended that the suggested value be 281 granted by IANA. 283 Type Description Reference 285 ----- ----------------------------------- --------- 287 0x04 Availability [This ID] 289 The registration procedure for this registry is Standards Action as 290 defined in [RFC8126]. 292 6. References 294 6.1. Normative References 296 [RFC2205] Braden, R., Ed., Zhang, L., Berson, S., Herzog, S., and 297 S.Jamin, "Resource ReSerVation Protocol (RSVP) - Version 1 298 Functional Specification", RFC 2205, September 1997. 300 [RFC3209] Awduche, D., Berger, L., Gan, D., Li, T., Srinivasan, 301 V.,and G. Swallow, "RSVP-TE: Extensions to RSVP for LSP 302 Tunnels", RFC 3209, December 2001. 304 [RFC3473] Berger, L., "Generalized Multi-Protocol Label Switching 305 (GMPLS) Signaling Resource ReserVation Protocol-Traffic 306 Engineering (RSVP-TE) Extensions", RFC 3473, January 2003. 308 [RFC6003] Papadimitriou, D. "Ethernet Traffic Parameters", RFC 6003, 309 October 2010. 311 6.2. Informative References 313 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 314 Requirement Levels", RFC 2119, March 1997. 316 [RFC8126] Cotton,M. and Leiba,B., and Narten T., "Guidelines for 317 Writing an IANA Considerations Section in RFCs", RFC 8126, 318 June 2017. 320 [RFC5920] Fang, L., "Security Framework for MPLS and GMPLS Networks", 321 RFC 5920, July 2010. 323 [G.827] ITU-T Recommendation, "Availability performance parameters 324 and objectives for end-to-end international constant bit- 325 rate digital paths", September, 2003. 327 [F.1703] ITU-R Recommendation, "Availability objectives for real 328 digital fixed wireless links used in 27 500 km 329 hypothetical reference paths and connections", January, 330 2005. 332 [P.530] ITU-R Recommendation," Propagation data and prediction 333 methods required for the design of terrestrial line-of- 334 sight systems", February, 2012 336 [EN 302 217] ETSI standard, "Fixed Radio Systems; Characteristics 337 and requirements for point-to-point equipment and 338 antennas", April, 2009 340 [RFC8330] H., Long, M., Ye, Mirsky, G., Alessandro, A., Shah, H., 341 "OSPF Traffic Engineering (OSPF-TE) Link Availability 342 Extension for Links with Variable Discrete Bandwidth", 343 RFC8330, February, 2018 345 7. Appendix: Bandwidth Availability Example 347 In mobile backhaul network, microwave links are very popular for 348 providing connection of last hops. In case of heavy rain, to 349 maintain the link connectivity, the microwave link MAY lower the 350 modulation level since demodulating the lower modulation level needs 351 a lower Signal-to-Noise Ratio (SNR). This is called adaptive 352 modulation technology [EN 302 217]. However, a lower modulation 353 level also means lower link bandwidth. When link bandwidth is 354 reduced because of modulation down-shifting, high-priority traffic 355 can be maintained, while lower-priority traffic is dropped. 356 Similarly, the copper links MAY change their link bandwidth due to 357 external interference. 359 Presuming that a link has three discrete bandwidth levels: 361 The link bandwidth under modulation level 1, e.g., QPSK, is 100 Mbps; 363 The link bandwidth under modulation level 2, e.g., 16QAM, is 200 364 Mbps; 366 The link bandwidth under modulation level 3, e.g., 256QAM, is 400 367 Mbps. 369 In sunny day, the modulation level 3 can be used to achieve 400 Mbps 370 link bandwidth. 372 A light rain with X mm/h rate triggers the system to change the 373 modulation level from level 3 to level 2, with bandwidth changing 374 from 400 Mbps to 200 Mbps. The probability of X mm/h rain in the 375 local area is 52 minutes in a year. Then the dropped 200 Mbps 376 bandwidth has 99.99% availability. 378 A heavy rain with Y(Y>X) mm/h rate triggers the system to change the 379 modulation level from level 2 to level 1, with bandwidth changing 380 from 200 Mbps to 100 Mbps. The probability of Y mm/h rain in the 381 local area is 26 minutes in a year. Then the dropped 100 Mbps 382 bandwidth has 99.995% availability. 384 For the 100M bandwidth of the modulation level 1, only the extreme 385 weather condition can cause the whole system unavailable, which only 386 happens for 5 minutes in a year. So the 100 Mbps bandwidth of the 387 modulation level 1 owns the availability of 99.999%. 389 In a word, the maximum bandwidth is 400 Mbps. According to the 390 weather condition, the sub-bandwidth and its availability are shown 391 as follows: 393 Sub-bandwidth (Mbps) Availability 395 ------------------ ------------ 397 200 99.99% 399 100 99.995% 401 100 99.999% 403 8. Acknowledgments 405 The authors would like to thank Khuzema Pithewan, Lou Berger, Yuji 406 Tochio, Dieter Beller, and Autumn Liu for their comments on the 407 document. 409 Authors' Addresses 410 Hao Long 411 Huawei Technologies Co., Ltd. 412 No.1899, Xiyuan Avenue, Hi-tech Western District 413 Chengdu 611731, P.R.China 415 Phone: +86-18615778750 416 Email: longhao@huawei.com 418 Min Ye (editor) 419 Huawei Technologies Co., Ltd. 420 No.1899, Xiyuan Avenue, Hi-tech Western District 421 Chengdu 611731, P.R.China 423 Email: amy.yemin@huawei.com 425 Greg Mirsky (editor) 426 ZTE 428 Email: gregimirsky@gmail.com 430 Alessandro D'Alessandro 431 Telecom Italia S.p.A 433 Email: alessandro.dalessandro@telecomitalia.it 435 Himanshu Shah 436 Ciena Corp. 437 3939 North First Street 438 San Jose, CA 95134 439 US 441 Email: hshah@ciena.com