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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 290, 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 17, 2019 11 Ethernet Traffic Parameters with Availability Information 12 draft-ietf-ccamp-rsvp-te-bandwidth-availability-13.txt 14 Abstract 16 A packet switching network may contain links with variable 17 bandwidth, e.g., copper, radio, etc. The bandwidth of such links is 18 sensitive to external environment (e.g., climate). Availability is 19 typically used for describing these links when during network 20 planning. This document introduces an optional Availability TLV in 21 Resource ReSerVation Protocol - Traffic Engineer (RSVP-TE) 22 signaling. This extension can be used to set up a Generalized Multi- 23 Protocol Label Switching (GMPLS) Label Switched Path (LSP) using the 24 Ethernet SENDER_TSPEC 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 17, 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............................... 5 68 3.1. Availability TLV........................................ 5 69 3.2. Signaling Process....................................... 5 70 4. Security Considerations...................................... 6 71 5. IANA Considerations ......................................... 6 72 5.1 Ethernet Sender TSpec TLVs ............................. 7 73 6. References .................................................. 7 74 6.1. Normative References.................................... 7 75 6.2. Informative References.................................. 8 76 7. Appendix: Bandwidth Availability Example..................... 8 77 8. Acknowledgments ............................................ 10 79 Conventions used in this document 81 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 82 "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and 83 "OPTIONAL" in this document are to be interpreted as described in 84 BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all 85 capitals, as shown here. 87 The following acronyms are used in this draft: 89 RSVP-TE Resource Reservation Protocol-Traffic Engineering 91 LSP Label Switched Path 92 SNR Signal-to-noise Ratio 94 TLV Type Length Value 96 LSA Link State Advertisement 98 1. Introduction 100 The RSVP-TE specification [RFC3209] and GMPLS extensions [RFC3473] 101 specify the signaling message including the bandwidth request for 102 setting up a Label Switched Path in a packet switching network. 104 Some data communication technologies allow seamless change of 105 maximum physical bandwidth through a set of known discrete values. 106 The parameter availability [G.827], [F.1703], [P.530] is often used 107 to describe the link capacity during network planning. The 108 availability is based on a time scale, which is a proportion of the 109 operating time that the requested bandwidth is ensured. A more 110 detailed example on the bandwidth availability can be found in 111 Appendix A. Assigning different bandwidth availability classes to 112 different types of services over such kind of links provides for a 113 more efficient planning of link capacity. To set up an LSP across 114 these links, bandwidth availability information is required for the 115 nodes to verify bandwidth satisfaction and make bandwidth 116 reservation. The bandwidth availability information should be 117 inherited from the bandwidth availability requirements of the 118 services expected to be carried on the LSP. For example, voice 119 service usually needs "five nines" bandwidth availability, while 120 non-real time services may adequately perform at four or three nines 121 bandwidth availability. Since different service types may need 122 different availabilities guarantees, multiple pairs may be required when signaling. 125 If the bandwidth availability requirement is not specified in the 126 signaling message, the bandwidth will be reserved as the highest 127 bandwidth availability. For example, the bandwidth with 99.999% 128 availability of a link is 100 Mbps; the bandwidth with 99.99% 129 availability is 200 Mbps. When a video application requests for 120 130 Mbps without bandwidth availability requirement, the system will 131 consider the request as 120 Mbps with 99.999% bandwidth 132 availability, while the available bandwidth with 99.999% bandwidth 133 availability is only 100 Mbps, therefore the LSP path cannot be set 134 up. But, in fact, the video application doesn't need 99.999% 135 bandwidth availability; 99.99% bandwidth availability is enough. In 136 this case, the LSP could be set up if bandwidth availability is also 137 specified in the signaling message. 139 To fulfill LSP setup by signaling in these scenarios, this document 140 specifies an Availability TLV. The Availability TLV can be 141 applicable to any kind of physical links with variable discrete 142 bandwidth, such as microwave or DSL. Multiple Availability TLVs 143 together with multiple Ethernet Bandwidth Profiles can be carried by 144 the Ethernet SENDER_TSPEC object [RFC6003]. Since the Ethernet 145 FLOWSPEC object has the same format as the Ethernet SENDER_TSPEC 146 object [RFC6003], the Availability TLV can also be carried by the 147 Ethernet FLOWSPEC object. 149 2. Overview 151 A tunnel in a packet switching network may span one or more links in 152 a network. To setup a Label Switched Path (LSP), a node may collect 153 link information which is advertised in a routing message, e.g., 154 OSPF TE LSA message, by network nodes to obtain network topology 155 information, and then calculate an LSP route based on the network 156 topology. The calculated LSP route is signaled using a PATH/RESV 157 message for setting up the LSP. 159 In case that there is (are) link(s) with variable discrete bandwidth 160 in a network, a requirement list should be 161 specified for an LSP at setup. Each pair 162 in the list means the listed bandwidth with specified availability 163 is required. The list could be derived from the results of service 164 planning for the LSP. 166 A node which has link(s) with variable discrete bandwidth attached 167 should contain a information list in its 168 OSPF TE LSA messages. The list provides the mapping between the link 169 nominal bandwidth and its availability level. This information can 170 then be used for path calculation by the node(s). The routing 171 extension for availability can be found in [RFC8330]. 173 When a node initiates a PATH/RESV signaling to set up an LSP, the 174 PATH message should carry the requirement 175 list as a bandwidth request. Intermediate node(s) will allocate the 176 bandwidth resource for each availability requirement from the 177 remaining bandwidth with corresponding availability. An error 178 message may be returned if any request 179 cannot be satisfied. 181 3. Extension to RSVP-TE Signaling 183 3.1. Availability TLV 185 An Availability TLV is defined as a TLV of the Ethernet SENDER_TSPEC 186 object [RFC6003] in this document. The Ethernet SENDER_TSPEC object 187 MAY include more than one Availability TLV. The Availability TLV has 188 the following format: 190 0 1 2 3 191 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 1 192 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 193 | Index | Reserved | 194 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 195 | Availability | 196 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 198 Figure 1: Availability TLV 200 Index (1 octet): 202 When the Availability TLV is included, it MUST be present along 203 with the Ethernet Bandwidth Profile TLV. If the bandwidth 204 requirements in the multiple Ethernet Bandwidth Profile TLVs have 205 different Availability requirements, multiple Availability TLVs 206 SHOULD be carried. In such a case, the Availability TLV has a one 207 to one correspondence with the Ethernet Bandwidth Profile TLV by 208 having the same value of Index field. If all the bandwidth 209 requirements in the Ethernet Bandwidth Profile have the same 210 Availability requirement, one Availability TLV SHOULD be carried. 211 In this case, the Index field is set to 0. 213 Reserved (3 octets): These bits SHOULD be set to zero when sent 214 and MUST be ignored when received. 216 Availability (4 octets): a 32-bit floating number describes the 217 decimal value of availability requirement for this bandwidth 218 request. The value MUST be less than 1and is usually expressed in 219 the value of 0.99/0.999/0.9999/0.99999. 221 3.2. Signaling Process 223 The source node initiates a PATH message which may carry a number of 224 bandwidth requests, including one or more Ethernet Bandwidth Profile 225 TLVs and one or more Availability TLVs. Each Ethernet Bandwidth 226 Profile TLV corresponds to an availability parameter in the 227 Availability TLV. 229 The intermediate and destination nodes check whether they can 230 satisfy the bandwidth requirements by comparing each bandwidth 231 request inside the SENDER_TSPEC objects with the remaining link sub- 232 bandwidth resource with respective availability guarantee on the 233 local link when the PATH message is received. 235 o When all requirement requests can 236 be satisfied (the requested bandwidth under each availability 237 parameter is smaller than or equal to the remaining bandwidth 238 under the corresponding availability parameter on its local 239 link), it SHOULD reserve the bandwidth resource from each 240 remaining sub-bandwidth portion on its local link to set up 241 this LSP. Optionally, the higher availability bandwidth can be 242 allocated to lower availability request when the lower 243 availability bandwidth cannot satisfy the request. 245 o When at least one requirement 246 request cannot be satisfied, it SHOULD generate PathErr message 247 with the error code "Admission Control Error" and the error 248 value "Requested Bandwidth Unavailable" (see [RFC2205]). 250 When two LSPs request bandwidth with the same availability 251 requirement, contention MUST be resolved by comparing the node IDs, 252 with the LSP with the higher node ID being assigned the reservation. 253 This is consistent with general contention resolution mechanism 254 provided in section 3.2 of [RFC3473]. 256 When a node does not support the Availability TLV, it SHOULD 257 generate PathErr message with the error code "Extended Class-Type 258 Error" and the error value "Class-Type mismatch" (see [RFC2205]). 260 4. Security Considerations 262 This document does not introduce any new security considerations to 263 the existing RSVP-TE signaling protocol. [RFC5920] provides an 264 overview of security vulnerabilities and protection mechanisms for 265 the GMPLS control plane. 267 5. IANA Considerations 269 IANA maintains registries and sub-registries for RSVP-TE used by 270 GMPLS. IANA is requested to make allocations from these registries 271 as set out in the following sections. 273 5.1 Ethernet Sender TSpec TLVs 275 IANA maintains a registry of GMPLS parameters called "Generalized 276 Multi-Protocol Label Switching (GMPLS) Signaling Parameters". 278 IANA has created a sub-registry called "Ethernet Sender TSpec TLVs / 279 Ethernet Flowspec TLVs" to contain the TLV type values for TLVs 280 carried in the Ethernet SENDER_TSPEC object. The sub-registry needs 281 to be updated to include the Availability TLV which is defined as 282 follow. This document proposes a suggested value for the 283 Availability sub-TLV; it is requested that the suggested value be 284 granted by IANA. 286 Type Description Reference 288 ----- ----------------------------------- --------- 290 0x04 Availability [This ID] 292 The registration procedure for this registry is Standards Action as 293 defined in [RFC8126]. 295 6. References 297 6.1. Normative References 299 [RFC2205] Braden, R., Ed., Zhang, L., Berson, S., Herzog, S., and 300 S.Jamin, "Resource ReSerVation Protocol (RSVP) - Version 1 301 Functional Specification", RFC 2205, September 1997. 303 [RFC3209] Awduche, D., Berger, L., Gan, D., Li, T., Srinivasan, 304 V.,and G. Swallow, "RSVP-TE: Extensions to RSVP for LSP 305 Tunnels", RFC 3209, December 2001. 307 [RFC3473] Berger, L., "Generalized Multi-Protocol Label Switching 308 (GMPLS) Signaling Resource ReserVation Protocol-Traffic 309 Engineering (RSVP-TE) Extensions", RFC 3473, January 2003. 311 [RFC6003] Papadimitriou, D. "Ethernet Traffic Parameters", RFC 6003, 312 October 2010. 314 [RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 315 2119 Key Words", BCP 14, RFC 8174, May 2017. 317 6.2. Informative References 319 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 320 Requirement Levels", RFC 2119, March 1997. 322 [RFC8126] Cotton,M. and Leiba,B., and Narten T., "Guidelines for 323 Writing an IANA Considerations Section in RFCs", RFC 8126, 324 June 2017. 326 [RFC5920] Fang, L., "Security Framework for MPLS and GMPLS 327 Networks", RFC 5920, July 2010. 329 [G.827] ITU-T Recommendation, "Availability performance parameters 330 and objectives for end-to-end international constant bit- 331 rate digital paths", September, 2003. 333 [F.1703] ITU-R Recommendation, "Availability objectives for real 334 digital fixed wireless links used in 27 500 km 335 hypothetical reference paths and connections", January, 336 2005. 338 [P.530] ITU-R Recommendation," Propagation data and prediction 339 methods required for the design of terrestrial line-of- 340 sight systems", February, 2012 342 [EN 302 217] ETSI standard, "Fixed Radio Systems; Characteristics 343 and requirements for point-to-point equipment and 344 antennas", April, 2009 346 [RFC8330] H., Long, M., Ye, Mirsky, G., Alessandro, A., Shah, H., 347 "OSPF Traffic Engineering (OSPF-TE) Link Availability 348 Extension for Links with Variable Discrete Bandwidth", 349 RFC8330, February, 2018 351 7. Appendix: Bandwidth Availability Example 353 In a mobile backhaul network, microwave links are very popular for 354 providing connections of last hops. In case of heavy rain 355 conditions, to maintain the link connectivity, the microwave link 356 MAY lower the modulation level since demodulating to a lower 357 modulation level provides for a lower Signal-to-Noise Ratio (SNR) 358 requirement. This is called adaptive modulation technology [EN 302 359 217]. However, a lower modulation level also means lower link 360 bandwidth. When link bandwidth is reduced because of modulation 361 down-shifting, high-priority traffic can be maintained, while lower- 362 priority traffic is dropped. Similarly, copper links may change 363 their link bandwidth due to external interference. 365 Presuming that a link has three discrete bandwidth levels: 367 The link bandwidth under modulation level 1, e.g., QPSK, is 100 368 Mbps; 370 The link bandwidth under modulation level 2, e.g., 16QAM, is 200 371 Mbps; 373 The link bandwidth under modulation level 3, e.g., 256QAM, is 400 374 Mbps. 376 On a sunny day, the modulation level 3 can be used to achieve 400 377 Mbps link bandwidth. 379 A light rain with X mm/h rate triggers the system to change the 380 modulation level from level 3 to level 2, with bandwidth changing 381 from 400 Mbps to 200 Mbps. The probability of X mm/h rain in the 382 local area is 52 minutes in a year. Then the dropped 200 Mbps 383 bandwidth has 99.99% availability. 385 A heavy rain with Y(Y>X) mm/h rate triggers the system to change the 386 modulation level from level 2 to level 1, with bandwidth changing 387 from 200 Mbps to 100 Mbps. The probability of Y mm/h rain in the 388 local area is 26 minutes in a year. Then the dropped 100 Mbps 389 bandwidth has 99.995% availability. 391 For the 100M bandwidth of the modulation level 1, only the extreme 392 weather condition can cause the whole system to be unavailable, 393 which only happens for 5 minutes in a year. So the 100 Mbps 394 bandwidth of the modulation level 1 owns the availability of 395 99.999%. 397 Therefore, the maximum bandwidth is 400 Mbps. According to the 398 weather condition, the sub-bandwidth and its availability are shown 399 as follows: 401 Sub-bandwidth (Mbps) Availability 403 ------------------ ------------ 405 200 99.99% 407 100 99.995% 409 100 99.999% 411 8. Acknowledgments 413 The authors would like to thank Deborah Brungard, Khuzema Pithewan, 414 Lou Berger, Yuji Tochio, Dieter Beller, and Autumn Liu for their 415 comments and contributions on the document. 417 Authors' Addresses 418 Hao Long 419 Huawei Technologies Co., Ltd. 420 No.1899, Xiyuan Avenue, Hi-tech Western District 421 Chengdu 611731, P.R.China 423 Phone: +86-18615778750 424 Email: longhao@huawei.com 426 Min Ye (editor) 427 Huawei Technologies Co., Ltd. 428 No.1899, Xiyuan Avenue, Hi-tech Western District 429 Chengdu 611731, P.R.China 431 Email: amy.yemin@huawei.com 433 Greg Mirsky (editor) 434 ZTE 436 Email: gregimirsky@gmail.com 438 Alessandro D'Alessandro 439 Telecom Italia S.p.A 441 Email: alessandro.dalessandro@telecomitalia.it 443 Himanshu Shah 444 Ciena Corp. 445 3939 North First Street 446 San Jose, CA 95134 447 US 449 Email: hshah@ciena.com