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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 283, but not defined -- Obsolete informational reference (is this intentional?): RFC 5226 (Obsoleted by RFC 8126) Summary: 0 errors (**), 0 flaws (~~), 2 warnings (==), 2 comments (--). 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 Individual 5 A.D'Alessandro 6 Telecom Italia S.p.A 7 H. Shah 8 Ciena 9 Expires: August 2017 February 14, 2017 11 Ethernet Traffic Parameters with Availability Information 12 draft-ietf-ccamp-rsvp-te-bandwidth-availability-06.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 Label Switched Path (LSP) in a Packet Switched 23 Network (PSN) that contains links with discretely variable 24 bandwidth. 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 August 14, 2017. 48 Copyright Notice 50 Copyright (c) 2017 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 PSN Packet Switched Network 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 PSN 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 a time scale, which is a proportion of the operating 109 time that the requested bandwidth is ensured. A more detailed 110 example on the bandwidth availability can be found in Appendix A. 111 Assigning different availability classes to different types of 112 service over such kind of links provides more efficient planning of 113 link capacity. To set up an LSP across these links, availability 114 information is required for the nodes to verify bandwidth 115 satisfaction and make bandwidth reservation. The availability 116 information should be inherited from the availability requirements 117 of the services expected to be carried on the LSP. For example, 118 voice service usually needs "five nines" availability, while non- 119 real time services may adequately perform at four or three nines 120 availability. Since different service types may need different 121 availabilities guarantees, multiple pairs 122 may be required when signaling. 124 If the availability requirement is not specified in the signaling 125 message, the bandwidth will be reserved as the highest availability. 126 For example, the bandwidth with 99.999% availability of a link is 127 100 Mbps; the bandwidth with 99.99% availability is 200 Mbps. When a 128 video application requests for 120 Mbps without availability 129 requirement, the system will consider the request as 120 Mbps with 130 99.999% availability, while the available bandwidth with 99.999% 131 availability is only 100 Mbps, therefore the LSP path cannot be set 132 up. But in fact, video application doesn't need 99.999% availability; 133 99.99% availability is enough. In this case, the LSP could be set up 134 if 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 in 141 the Ethernet SENDER_TSPEC object. 143 2. Overview 145 A PSN tunnel may span one or more links in a network. To setup a 146 Label Switched Path (LSP), a node may collect link information which 147 is spread in routing message, e.g., OSPF TE LSA message, by network 148 nodes to get to know about the network topology, and calculate out 149 an LSP route based on the network topology, and send the calculated 150 LSP route to signaling to initiate a PATH/RESV message for setting 151 up the LSP. 153 In case that there is(are) link(s) with variable discrete bandwidth 154 in a network, a requirement list should be 155 specified for an LSP. Each pair in the 156 list means that listed bandwidth with specified availability is 157 required. The list could be inherited from the results of service 158 planning for the LSP. 160 A node which has link(s) with variable discrete bandwidth attached 161 should contain a information list in its 162 OSPF TE LSA messages. The list provides the mapping between the link 163 nominal bandwidth and its availability level. This information is 164 used for path calculation by the node(s). The routing extension for 165 availability can be found in [ARTE]. 167 When a node initiates a PATH/RESV signaling to set up an LSP, the 168 PATH message should carry the requirement 169 list as bandwidth request. Intermediate node(s) will allocate the 170 bandwidth resource for each availability requirement from the 171 remaining bandwidth with corresponding availability. An error 172 message may be returned if any request 173 cannot be satisfied. 175 3. Extension to RSVP-TE Signaling 177 3.1. Availability TLV 179 An Availability TLV is defined as a TLV of the Ethernet 180 SENDEDR_TSPEC object [RFC6003] in this document. The Ethernet 181 SENDER_TSPEC object MAY include more than one Availability TLV. The 182 Availability TLV has the following format: 184 0 1 2 3 185 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 1 186 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 187 | Index | Reserved | 188 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 189 | Availability | 190 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 192 Figure 1: Availability TLV 194 Index (1 octet): 196 The Availability TLV MUST come along with Ethernet Bandwidth 197 Profile TLV. If the bandwidth requirements in the multiple 198 Ethernet Bandwidth Profile TLVs have different Availability 199 requirements, multiple Availability TLVs SHOULD be carried. In 200 such a case, the Availability TLV has one to one correspondence 201 with Ethernet Bandwidth Profile TLV by having the same value of 202 Index field. If all the bandwidth requirements in the Ethernet 203 Bandwidth Profile have the same Availability requirement, one 204 Availability TLV SHOULD be carried. In this case, the Index field 205 is set to 0. 207 Reserved (3 octets): These bits SHOULD be set to zero when sent 208 and MUST be ignored when received. 210 Availability (4 octets): a 32-bit floating number describes the 211 decimal value of availability requirement for this bandwidth 212 request. The value MUST be less than 1and is usually expressed in 213 the value of 0.99/0.999/0.9999/0.99999. 215 3.2. Signaling Process 217 The source node initiates PATH messages which carry a number of 218 bandwidth request information, including one or more Ethernet 219 Bandwidth Profile TLVs and one or more Availability TLVs. Each 220 Ethernet Bandwidth Profile TLV corresponds to an availability 221 parameter in the Availability TLV. 223 The intermediate and destination nodes check whether they can 224 satisfy the bandwidth requirements by comparing each bandwidth 225 requirement inside the SENDER_TSPEC objects with the remaining link 226 sub-bandwidth resource with respective availability guarantee on the 227 local link when received the PATH message. 229 o If all requirements can be 230 satisfied (the requested bandwidth under each availability 231 parameter is smaller than or equal to the remaining bandwidth 232 under the corresponding availability parameter on its local 233 link), it SHOULD reserve the bandwidth resource from each 234 remaining sub-bandwidth portion on its local link to set up 235 this LSP. Optionally, the higher availability bandwidth can be 236 allocated to lower availability request when the lower 237 availability bandwidth cannot satisfy the request. 239 o If at least one requirement cannot 240 be satisfied, it SHOULD generate PathErr message with the error 241 code "Admission Control Error" and the error value "Requested 242 Bandwidth Unavailable" (see [RFC2205]). 244 If two LSPs request for the bandwidth with the same availability 245 requirement, a way to resolve the contention is comparing the node 246 ID, the node with the higher node ID will win the contention. More 247 details can be found in [RFC3473]. 249 If a node does not support Availability TLV, it SHOULD generate 250 PathErr message with the error code "Extended Class-Type Error" and 251 the error value "Class-Type mismatch" (see [RFC2205]). 253 4. Security Considerations 255 This document does not introduce new security considerations to the 256 existing RSVP-TE signaling protocol. [RFC5920] provides an overview 257 of security vulnerabilities and protection mechanisms for the GMPLS 258 control plane. 260 5. IANA Considerations 262 IANA maintains registries and sub-registries for RSVP-TE used by 263 GMPLS. IANA is requested to make allocations from these registries 264 as set out in the following sections. 266 5.1 Ethernet Sender TSpec TLVs 268 IANA maintains a registry of GMPLS parameters called "Generalized 269 Multi-Protocol Label Switching (GMPLS) Signaling Parameters". 271 IANA has created a sub-registry called "Ethernet Sender TSpec TLVs / 272 Ethernet Flowspec TLVs" to contain the TLV type values for TLVs 273 carried in the Ethernet SENDER_TSPEC object. The sub-registry is 274 needed to be updated to include the Availability TLV which is 275 defined as follow. This document proposes a suggested value for the 276 Availability sub-TLV; it is recommended that the suggested value be 277 granted by IANA. 279 Type Description Reference 281 ----- ----------------------------------- --------- 283 0x04 Availability [This ID] 285 The registration procedure for this registry is Standards Action as 286 defined in [RFC5226]. 288 6. References 290 6.1. Normative References 292 [RFC2205] Braden, R., Ed., Zhang, L., Berson, S., Herzog, S., and 293 S.Jamin, "Resource ReSerVation Protocol (RSVP) - Version 1 294 Functional Specification", RFC 2205, September 1997. 296 [RFC3209] Awduche, D., Berger, L., Gan, D., Li, T., Srinivasan, 297 V.,and G. Swallow, "RSVP-TE: Extensions to RSVP for LSP 298 Tunnels", RFC 3209, December 2001. 300 [RFC3473] Berger, L., "Generalized Multi-Protocol Label Switching 301 (GMPLS) Signaling Resource ReserVation Protocol-Traffic 302 Engineering (RSVP-TE) Extensions", RFC 3473, January 2003. 304 [RFC6003] Papadimitriou, D. "Ethernet Traffic Parameters", RFC 6003, 305 October 2010. 307 6.2. Informative References 309 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 310 Requirement Levels", RFC 2119, March 1997. 312 [RFC5226] Narten,T. and H. Alvestrand, "Guidelines for Writing an 313 IANA Considerations Section in RFCs", RFC 5226, May 2008. 315 [RFC5920] Fang, L., "Security Framework for MPLS and GMPLS Networks", 316 RFC 5920, July 2010. 318 [G.827] ITU-T Recommendation, "Availability performance parameters 319 and objectives for end-to-end international constant bit- 320 rate digital paths", September, 2003. 322 [F.1703] ITU-R Recommendation, "Availability objectives for real 323 digital fixed wireless links used in 27 500 km 324 hypothetical reference paths and connections", January, 325 2005. 327 [P.530] ITU-R Recommendation," Propagation data and prediction 328 methods required for the design of terrestrial line-of- 329 sight systems", February, 2012 331 [EN 302 217] ETSI standard, "Fixed Radio Systems; Characteristics 332 and requirements for point-to-point equipment and 333 antennas", April, 2009 335 [ARTE] H., Long, M., Ye, Mirsky, G., Alessandro, A., Shah, H., 336 "OSPF Routing Extension for Links with Variable Discrete 337 Bandwidth", Work in Progress, October, 2016 339 7. Appendix: Bandwidth Availability Example 341 In mobile backhaul network, microwave links are very popular for 342 providing connection of last hops. In case of heavy rain, to 343 maintain the link connectivity, the microwave link MAY lower the 344 modulation level since demodulating the lower modulation level needs 345 a lower Signal-to-Noise Ratio (SNR). This is called adaptive 346 modulation technology [EN 302 217]. However, a lower modulation 347 level also means lower link bandwidth. When link bandwidth is 348 reduced because of modulation down-shifting, high-priority traffic 349 can be maintained, while lower-priority traffic is dropped. 350 Similarly, the copper links MAY change their link bandwidth due to 351 external interference. 353 Presuming that a link has three discrete bandwidth levels: 355 The link bandwidth under modulation level 1, e.g., QPSK, is 100 Mbps; 357 The link bandwidth under modulation level 2, e.g., 16QAM, is 200 358 Mbps; 360 The link bandwidth under modulation level 3, e.g., 256QAM, is 400 361 Mbps. 363 In sunny day, the modulation level 3 can be used to achieve 400 Mbps 364 link bandwidth. 366 A light rain with X mm/h rate triggers the system to change the 367 modulation level from level 3 to level 2, with bandwidth changing 368 from 400 Mbps to 200 Mbps. The probability of X mm/h rain in the 369 local area is 52 minutes in a year. Then the dropped 200 Mbps 370 bandwidth has 99.99% availability. 372 A heavy rain with Y(Y>X) mm/h rate triggers the system to change the 373 modulation level from level 2 to level 1, with bandwidth changing 374 from 200 Mbps to 100 Mbps. The probability of Y mm/h rain in the 375 local area is 26 minutes in a year. Then the dropped 100 Mbps 376 bandwidth has 99.995% availability. 378 For the 100M bandwidth of the modulation level 1, only the extreme 379 weather condition can cause the whole system unavailable, which only 380 happens for 5 minutes in a year. So the 100 Mbps bandwidth of the 381 modulation level 1 owns the availability of 99.999%. 383 In a word, the maximum bandwidth is 400 Mbps. According to the 384 weather condition, the sub-bandwidth and its availability are shown 385 as follows: 387 Sub-bandwidth(Mbps) Availability 389 ------------------ ------------ 391 200 99.99% 393 100 99.995% 395 100 99.999% 397 8. Acknowledgments 399 The authors would like to thank Khuzema Pithewan, Lou Berger, Yuji 400 Tochio, Dieter Beller, and Autumn Liu for their comments on the 401 document. 403 Authors' Addresses 404 Hao Long 405 Huawei Technologies Co., Ltd. 406 No.1899, Xiyuan Avenue, Hi-tech Western District 407 Chengdu 611731, P.R.China 409 Phone: +86-18615778750 410 Email: longhao@huawei.com 412 Min Ye (editor) 413 Huawei Technologies Co., Ltd. 414 No.1899, Xiyuan Avenue, Hi-tech Western District 415 Chengdu 611731, P.R.China 417 Email: amy.yemin@huawei.com 419 Greg Mirsky (editor) 420 Individual 422 Email: gregimirsky@gmail.com 424 Alessandro D'Alessandro 425 Telecom Italia S.p.A 427 Email: alessandro.dalessandro@telecomitalia.it 429 Himanshu Shah 430 Ciena Corp. 431 3939 North First Street 432 San Jose, CA 95134 433 US 435 Email: hshah@ciena.com