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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 284, 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: March 2019 September 27, 2018 11 Ethernet Traffic Parameters with Availability Information 12 draft-ietf-ccamp-rsvp-te-bandwidth-availability-10.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 March 27, 2019. 48 Copyright Notice 50 Copyright (c) 2018 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 availability classes to different types of 110 service over such kind of links provides more efficient planning of 111 link capacity. To set up an LSP across these links, availability 112 information is required for the nodes to verify bandwidth 113 satisfaction and make bandwidth reservation. The availability 114 information should be inherited from the availability requirements 115 of the services expected to be carried on the LSP. For example, 116 voice service usually needs "five nines" availability, while non- 117 real time services may adequately perform at four or three nines 118 availability. Since different service types may need different 119 availabilities guarantees, multiple pairs 120 may be required when signaling. 122 If the availability requirement is not specified in the signaling 123 message, the bandwidth will be reserved as the highest availability. 124 For example, the bandwidth with 99.999% availability of a link is 125 100 Mbps; the bandwidth with 99.99% availability is 200 Mbps. When a 126 video application requests for 120 Mbps without availability 127 requirement, the system will consider the request as 120 Mbps with 128 99.999% availability, while the available bandwidth with 99.999% 129 availability is only 100 Mbps, therefore the LSP path cannot be set 130 up. But in fact, video application doesn't need 99.999% availability; 131 99.99% availability is enough. In this case, the LSP could be set up 132 if availability is specified in the signaling message. 134 To fulfill LSP setup by signaling in these scenarios, this document 135 specifies an Availability TLV. The Availability TLV can be 136 applicable to any kind of physical links with variable discrete 137 bandwidth, such as microwave or DSL. Multiple Availability TLVs 138 together with multiple Ethernet Bandwidth Profiles can be carried by 139 the Ethernet SENDER_TSPEC object [RFC6003]. Since the Ethernet 140 FLOWSPEC object has the same format as the Ethernet SENDER_TSPEC 141 object [RFC6003], the Availability TLV can also be carried by the 142 Ethernet FLOWSPEC object. 144 2. Overview 146 A tunnel in a packet switching network may span one or more links in 147 a network. To setup a Label Switched Path (LSP), a node may collect 148 link information which is spread in routing message, e.g., OSPF TE 149 LSA message, by network nodes to get to know about the network 150 topology, and calculate out an LSP route based on the network 151 topology, and send the calculated LSP route to signaling to initiate 152 a PATH/RESV message for setting up the LSP. 154 In case that there is (are) link(s) with variable discrete bandwidth 155 in a network, a requirement list should be 156 specified for an LSP. Each pair in the 157 list means that listed bandwidth with specified availability is 158 required. The list could be inherited from the results of service 159 planning for the LSP. 161 A node which has link(s) with variable discrete bandwidth attached 162 should contain a information list in its 163 OSPF TE LSA messages. The list provides the mapping between the link 164 nominal bandwidth and its availability level. This information is 165 used for path calculation by the node(s). The routing extension for 166 availability can be found in [RFC8330]. 168 When a node initiates a PATH/RESV signaling to set up an LSP, the 169 PATH message should carry the requirement 170 list as bandwidth request. Intermediate node(s) will allocate the 171 bandwidth resource for each availability requirement from the 172 remaining bandwidth with corresponding availability. An error 173 message may be returned if any request 174 cannot be satisfied. 176 3. Extension to RSVP-TE Signaling 178 3.1. Availability TLV 180 An Availability TLV is defined as a TLV of the Ethernet SENDER_TSPEC 181 object [RFC6003] in this document. The Ethernet SENDER_TSPEC object 182 MAY include more than one Availability TLV. The Availability TLV has 183 the following format: 185 0 1 2 3 186 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 1 187 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 188 | Index | Reserved | 189 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 190 | Availability | 191 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 193 Figure 1: Availability TLV 195 Index (1 octet): 197 The Availability TLV MUST come along with Ethernet Bandwidth 198 Profile TLV. If the bandwidth requirements in the multiple 199 Ethernet Bandwidth Profile TLVs have different Availability 200 requirements, multiple Availability TLVs SHOULD be carried. In 201 such a case, the Availability TLV has one to one correspondence 202 with Ethernet Bandwidth Profile TLV by having the same value of 203 Index field. If all the bandwidth requirements in the Ethernet 204 Bandwidth Profile have the same Availability requirement, one 205 Availability TLV SHOULD be carried. In this case, the Index field 206 is set to 0. 208 Reserved (3 octets): These bits SHOULD be set to zero when sent 209 and MUST be ignored when received. 211 Availability (4 octets): a 32-bit floating number describes the 212 decimal value of availability requirement for this bandwidth 213 request. The value MUST be less than 1and is usually expressed in 214 the value of 0.99/0.999/0.9999/0.99999. 216 3.2. Signaling Process 218 The source node initiates PATH messages which carry a number of 219 bandwidth request information, including one or more Ethernet 220 Bandwidth Profile TLVs and one or more Availability TLVs. Each 221 Ethernet Bandwidth Profile TLV corresponds to an availability 222 parameter in the Availability TLV. 224 The intermediate and destination nodes check whether they can 225 satisfy the bandwidth requirements by comparing each bandwidth 226 requirement inside the SENDER_TSPEC objects with the remaining link 227 sub-bandwidth resource with respective availability guarantee on the 228 local link when received the PATH message. 230 o If all requirements can be 231 satisfied (the requested bandwidth under each availability 232 parameter is smaller than or equal to the remaining bandwidth 233 under the corresponding availability parameter on its local 234 link), it SHOULD reserve the bandwidth resource from each 235 remaining sub-bandwidth portion on its local link to set up 236 this LSP. Optionally, the higher availability bandwidth can be 237 allocated to lower availability request when the lower 238 availability bandwidth cannot satisfy the request. 240 o If at least one requirement cannot 241 be satisfied, it SHOULD generate PathErr message with the error 242 code "Admission Control Error" and the error value "Requested 243 Bandwidth Unavailable" (see [RFC2205]). 245 If two LSPs request for the bandwidth with the same availability 246 requirement, a way to resolve the contention is comparing the node 247 ID, the node with the higher node ID will win the contention. More 248 details can be found in [RFC3473]. 250 If a node does not support Availability TLV, it SHOULD generate 251 PathErr message with the error code "Extended Class-Type Error" and 252 the error value "Class-Type mismatch" (see [RFC2205]). 254 4. Security Considerations 256 This document does not introduce new security considerations to the 257 existing RSVP-TE signaling protocol. [RFC5920] provides an overview 258 of security vulnerabilities and protection mechanisms for the GMPLS 259 control plane. 261 5. IANA Considerations 263 IANA maintains registries and sub-registries for RSVP-TE used by 264 GMPLS. IANA is requested to make allocations from these registries 265 as set out in the following sections. 267 5.1 Ethernet Sender TSpec TLVs 269 IANA maintains a registry of GMPLS parameters called "Generalized 270 Multi-Protocol Label Switching (GMPLS) Signaling Parameters". 272 IANA has created a sub-registry called "Ethernet Sender TSpec TLVs / 273 Ethernet Flowspec TLVs" to contain the TLV type values for TLVs 274 carried in the Ethernet SENDER_TSPEC object. The sub-registry is 275 needed to be updated to include the Availability TLV which is 276 defined as follow. This document proposes a suggested value for the 277 Availability sub-TLV; it is recommended that the suggested value be 278 granted by IANA. 280 Type Description Reference 282 ----- ----------------------------------- --------- 284 0x04 Availability [This ID] 286 The registration procedure for this registry is Standards Action as 287 defined in [RFC8126]. 289 6. References 291 6.1. Normative References 293 [RFC2205] Braden, R., Ed., Zhang, L., Berson, S., Herzog, S., and 294 S.Jamin, "Resource ReSerVation Protocol (RSVP) - Version 1 295 Functional Specification", RFC 2205, September 1997. 297 [RFC3209] Awduche, D., Berger, L., Gan, D., Li, T., Srinivasan, 298 V.,and G. Swallow, "RSVP-TE: Extensions to RSVP for LSP 299 Tunnels", RFC 3209, December 2001. 301 [RFC3473] Berger, L., "Generalized Multi-Protocol Label Switching 302 (GMPLS) Signaling Resource ReserVation Protocol-Traffic 303 Engineering (RSVP-TE) Extensions", RFC 3473, January 2003. 305 [RFC6003] Papadimitriou, D. "Ethernet Traffic Parameters", RFC 6003, 306 October 2010. 308 6.2. Informative References 310 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 311 Requirement Levels", RFC 2119, March 1997. 313 [RFC8126] Cotton,M. and Leiba,B., and Narten T., "Guidelines for 314 Writing an IANA Considerations Section in RFCs", RFC 8126, 315 June 2017. 317 [RFC5920] Fang, L., "Security Framework for MPLS and GMPLS Networks", 318 RFC 5920, July 2010. 320 [G.827] ITU-T Recommendation, "Availability performance parameters 321 and objectives for end-to-end international constant bit- 322 rate digital paths", September, 2003. 324 [F.1703] ITU-R Recommendation, "Availability objectives for real 325 digital fixed wireless links used in 27 500 km 326 hypothetical reference paths and connections", January, 327 2005. 329 [P.530] ITU-R Recommendation," Propagation data and prediction 330 methods required for the design of terrestrial line-of- 331 sight systems", February, 2012 333 [EN 302 217] ETSI standard, "Fixed Radio Systems; Characteristics 334 and requirements for point-to-point equipment and 335 antennas", April, 2009 337 [RFC8330] H., Long, M., Ye, Mirsky, G., Alessandro, A., Shah, H., 338 "OSPF Traffic Engineering (OSPF-TE) Link Availability 339 Extension for Links with Variable Discrete Bandwidth", 340 RFC8330, February, 2018 342 7. Appendix: Bandwidth Availability Example 344 In mobile backhaul network, microwave links are very popular for 345 providing connection of last hops. In case of heavy rain, to 346 maintain the link connectivity, the microwave link MAY lower the 347 modulation level since demodulating the lower modulation level needs 348 a lower Signal-to-Noise Ratio (SNR). This is called adaptive 349 modulation technology [EN 302 217]. However, a lower modulation 350 level also means lower link bandwidth. When link bandwidth is 351 reduced because of modulation down-shifting, high-priority traffic 352 can be maintained, while lower-priority traffic is dropped. 353 Similarly, the copper links MAY change their link bandwidth due to 354 external interference. 356 Presuming that a link has three discrete bandwidth levels: 358 The link bandwidth under modulation level 1, e.g., QPSK, is 100 Mbps; 360 The link bandwidth under modulation level 2, e.g., 16QAM, is 200 361 Mbps; 363 The link bandwidth under modulation level 3, e.g., 256QAM, is 400 364 Mbps. 366 In sunny day, the modulation level 3 can be used to achieve 400 Mbps 367 link bandwidth. 369 A light rain with X mm/h rate triggers the system to change the 370 modulation level from level 3 to level 2, with bandwidth changing 371 from 400 Mbps to 200 Mbps. The probability of X mm/h rain in the 372 local area is 52 minutes in a year. Then the dropped 200 Mbps 373 bandwidth has 99.99% availability. 375 A heavy rain with Y(Y>X) mm/h rate triggers the system to change the 376 modulation level from level 2 to level 1, with bandwidth changing 377 from 200 Mbps to 100 Mbps. The probability of Y mm/h rain in the 378 local area is 26 minutes in a year. Then the dropped 100 Mbps 379 bandwidth has 99.995% availability. 381 For the 100M bandwidth of the modulation level 1, only the extreme 382 weather condition can cause the whole system unavailable, which only 383 happens for 5 minutes in a year. So the 100 Mbps bandwidth of the 384 modulation level 1 owns the availability of 99.999%. 386 In a word, the maximum bandwidth is 400 Mbps. According to the 387 weather condition, the sub-bandwidth and its availability are shown 388 as follows: 390 Sub-bandwidth (Mbps) Availability 392 ------------------ ------------ 394 200 99.99% 396 100 99.995% 398 100 99.999% 400 8. Acknowledgments 402 The authors would like to thank Khuzema Pithewan, Lou Berger, Yuji 403 Tochio, Dieter Beller, and Autumn Liu for their comments on the 404 document. 406 Authors' Addresses 407 Hao Long 408 Huawei Technologies Co., Ltd. 409 No.1899, Xiyuan Avenue, Hi-tech Western District 410 Chengdu 611731, P.R.China 412 Phone: +86-18615778750 413 Email: longhao@huawei.com 415 Min Ye (editor) 416 Huawei Technologies Co., Ltd. 417 No.1899, Xiyuan Avenue, Hi-tech Western District 418 Chengdu 611731, P.R.China 420 Email: amy.yemin@huawei.com 422 Greg Mirsky (editor) 423 ZTE 425 Email: gregimirsky@gmail.com 427 Alessandro D'Alessandro 428 Telecom Italia S.p.A 430 Email: alessandro.dalessandro@telecomitalia.it 432 Himanshu Shah 433 Ciena Corp. 434 3939 North First Street 435 San Jose, CA 95134 436 US 438 Email: hshah@ciena.com