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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 325, but not defined -- Possible downref: Non-RFC (?) normative reference: ref. 'IEEE754' 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 ZTE 5 A.D'Alessandro 6 Telecom Italia S.p.A 7 H. Shah 8 Ciena 9 Expires: November 2019 May 5, 2019 11 Ethernet Traffic Parameters with Availability Information 12 draft-ietf-ccamp-rsvp-te-bandwidth-availability-16.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 doing network 20 planning. This document introduces an optional Bandwidth 21 Availability TLV in Resource ReSerVation Protocol - Traffic Engineer 22 (RSVP-TE) signaling. This extension can be used to set up a 23 Generalized Multi-Protocol Label Switching (GMPLS) Label Switched 24 Path (LSP) in conjunction with the 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 November 5, 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. Bandwidth Availability TLV.............................. 5 69 3.2. Signaling Process....................................... 6 70 4. Security Considerations...................................... 7 71 5. IANA Considerations ......................................... 7 72 5.1 Ethernet Sender TSpec TLVs ............................. 7 73 6. References .................................................. 8 74 6.1. Normative References.................................... 8 75 6.2. Informative References.................................. 9 76 7. Appendix: Bandwidth Availability Example..................... 9 77 8. Acknowledgments ............................................ 11 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 likely be reserved as the 127 highest bandwidth availability. Suppose, for example, the bandwidth 128 with 99.999% availability of a link is 100 Mbps; the bandwidth with 129 99.99% availability is 200 Mbps. When a video application makes a 130 request for 120 Mbps without bandwidth availability requirement, the 131 system will 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 a Bandwidth Availability TLV. The Bandwidth Availability 141 TLV can be applicable to any kind of physical links with variable 142 discrete bandwidth, such as microwave or DSL. Multiple Bandwidth 143 Availability TLVs together with multiple Ethernet Bandwidth Profiles 144 can be carried by the Ethernet SENDER_TSPEC object [RFC6003]. Since 145 the Ethernet FLOWSPEC object has the same format as the Ethernet 146 SENDER_TSPEC object [RFC6003], the Bandwidth Availability TLV can 147 also be carried by the 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. Bandwidth Availability TLV 185 A Bandwidth Availability TLV is defined as a TLV of the Ethernet 186 SENDER_TSPEC object [RFC6003] in this document. The Ethernet 187 SENDER_TSPEC object MAY include more than one Bandwidth Availability 188 TLV. The Bandwidth Availability TLV has 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 | Type | Length | 194 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 195 | Index | Reserved | 196 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 197 | Availability | 198 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 200 Figure 1: Bandwidth Availability TLV 202 Type (2 octets): 0x04(suggested; TBD by IANA) 204 Length (2 octets): 0x0C. Indicates the length in bytes of the 205 whole TLV including the Type and Length fields, in this case 12 206 bytes. 208 Index (1 octet): 210 When the Bandwidth Availability TLV is included, the Ethernet 211 Bandwidth Profile TLV MUST also be included. If there are multiple 212 bandwidth requirements present (in multiple Ethernet Bandwidth 213 Profile TLVs) and they have different availability requirements, 214 multiple Bandwidth Availability TLVs MUST be carried. In such a 215 case, the Bandwidth Availability TLV has a one to one 216 correspondence with the Ethernet Bandwidth Profile TLV by having 217 the same value of Index field. If all the bandwidth requirements 218 in the Ethernet Bandwidth Profile have the same Availability 219 requirement, one Bandwidth Availability TLV SHOULD be carried. In 220 this case, the Index field is set to 0. 222 Reserved (3 octets): These bits SHOULD be set to zero when sent 223 and MUST be ignored when received. 225 Availability (4 octets): a 32-bit floating-point number in binary 226 interchange format [IEEE754] describes the decimal value of the 227 availability requirement for this bandwidth request. The value 228 MUST be less than 1 and is usually expressed in the value of 229 0.99/0.999/0.9999/0.99999. The IEEE floating-point number is used 230 here to align with [RFC8330]. However when representing values 231 higher than 0.999999, the floating-point number starts to 232 introduce errors in relation to intended precision. However in 233 reality, 0.99999 is normally considered as the highest 234 availability value (5 minutes outage in a year) in telecom 235 network, therefore the use of floating-point number in 236 availability is acceptable. 238 3.2. Signaling Process 240 The source node initiates a PATH message which may carry a number of 241 bandwidth requests, including one or more Ethernet Bandwidth Profile 242 TLVs and one or more Bandwidth Availability TLVs. Each Ethernet 243 Bandwidth Profile TLV corresponds to an availability parameter in 244 the associated Bandwidth Availability TLV. 246 The intermediate and destination nodes check whether they can 247 satisfy the bandwidth requirements by comparing each bandwidth 248 request inside the SENDER_TSPEC objects with the remaining link sub- 249 bandwidth resource with respective availability guarantee on the 250 local link when the PATH message is received. 252 o When all requirement requests can 253 be satisfied (the requested bandwidth under each availability 254 parameter is smaller than or equal to the remaining bandwidth 255 under the corresponding availability parameter on its local 256 link), the node SHOULD reserve the bandwidth resource from each 257 remaining sub-bandwidth portion on its local link to set up 258 this LSP. Optionally, a higher availability bandwidth can be 259 allocated to a lower availability request when the lower 260 availability bandwidth cannot satisfy the request. 262 o When at least one requirement 263 request cannot be satisfied, the node SHOULD generate PathErr 264 message with the error code "Admission Control Error" and the 265 error value "Requested Bandwidth Unavailable" (see [RFC2205]). 267 When two LSPs request bandwidth with the same availability 268 requirement, contention MUST be resolved by comparing the node IDs, 269 with the LSP with the higher node ID being assigned the reservation. 270 This is consistent with general contention resolution mechanism 271 provided in section 4.2 of [RFC3471]. 273 When a node does not support the Bandwidth Availability TLV, the 274 node should send a PathErr message with error code "Unknown 275 Attributes TLV", as specified in [RFC5420]. An LSP could also be set 276 up in this case if there's enough bandwidth (the availability level 277 of the reserved bandwidth is unknown). When a node receives 278 Bandwidth Availability TLVs with a mix of zero index and non-zero 279 index, the message MUST be ignored and MUST NOT be propagated. When 280 a node receives Bandwidth Availability TLVs (non-zero index) with no 281 matching index value among the bandwidth-TLVs, the message MUST be 282 ignored and MUST NOT be propagated. When a node receives several 283 pairs, but there are extra bandwidth-TLVs 284 without matching the index of any Availability-TLV, the extra 285 bandwidth-TLVs MUST be ignored and MUST NOT be propagated. 287 4. Security Considerations 289 This document defines a Bandwidth Availability TLV in RSVP-TE 290 signaling used in GMPLS networks. [RFC3945] notes that 291 authentication in GMPLS systems may use the authentication 292 mechanisms of the component protocols. [RFC5920] provides an 293 overview of security vulnerabilities and protection mechanisms for 294 the GMPLS control plane. Especially section 7.1.2 of [RFC5920] 295 discusses the control-plane protection with RSVP-TE by using general 296 RSVP security tools, limiting the impact of an attack on control- 297 plane resources, and authentication for RSVP messages. Moreover, the 298 GMPLS network is often considered to be a closed network such that 299 insertion, modification, or inspection of packets by an outside 300 party is not possible. 302 5. IANA Considerations 304 IANA maintains registries and sub-registries for RSVP-TE used by 305 GMPLS. IANA is requested to make allocations from these registries 306 as set out in the following sections. 308 5.1 Ethernet Sender TSpec TLVs 310 IANA maintains a registry of GMPLS parameters called "Generalized 311 Multi-Protocol Label Switching (GMPLS) Signaling Parameters". 313 IANA has created a sub-registry called "Ethernet Sender TSpec TLVs / 314 Ethernet Flowspec TLVs" to contain the TLV type values for TLVs 315 carried in the Ethernet SENDER_TSPEC object. The sub-registry needs 316 to be updated to include the Bandwidth Availability TLV which is 317 defined as follow. This document proposes a suggested value for the 318 Availability sub-TLV; it is requested that the suggested value be 319 granted by IANA. 321 Type Description Reference 323 ----- -------------------- --------- 325 0x04 Bandwidth Availability [This ID] 327 (Suggested; TBD by IANA) 329 The registration procedure for this registry is Standards Action as 330 defined in [RFC8126]. 332 6. References 334 6.1. Normative References 336 [RFC2205] Braden, R., Ed., Zhang, L., Berson, S., Herzog, S., and 337 S.Jamin, "Resource ReSerVation Protocol (RSVP) - Version 1 338 Functional Specification", RFC 2205, September 1997. 340 [RFC3209] Awduche, D., Berger, L., Gan, D., Li, T., Srinivasan, 341 V.,and G. Swallow, "RSVP-TE: Extensions to RSVP for LSP 342 Tunnels", RFC 3209, December 2001. 344 [RFC3473] Berger, L., "Generalized Multi-Protocol Label Switching 345 (GMPLS) Signaling Resource ReserVation Protocol-Traffic 346 Engineering (RSVP-TE) Extensions", RFC 3473, January 2003. 348 [RFC3471] Berger, L., "Generalized Multi-Protocol Label Switching 349 (GMPLS) Signaling Functional Description", RFC 3471, 350 January 2003. 352 [RFC5420] Farrel, A., Papadimitriou, D., Vasseur JP., and Ayyangar 353 A., "Encoding of Attributes for MPLS LSP Establishment 354 Using Resource Reservation Protocol Traffic Engineering 355 (RSVP-TE)", RFC 5420, February 2009. 357 [RFC6003] Papadimitriou, D. "Ethernet Traffic Parameters", RFC 6003, 358 October 2010. 360 [RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 361 2119 Key Words", BCP 14, RFC 8174, May 2017. 363 [IEEE754] IEEE, "IEEE Standard for Floating-Point Arithmetic",IEEE 364 754-2008, DOI 10.1109/IEEESTD.2008.4610935, 2008, 365 . 368 6.2. Informative References 370 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 371 Requirement Levels", RFC 2119, March 1997. 373 [RFC8126] Cotton,M. and Leiba,B., and Narten T., "Guidelines for 374 Writing an IANA Considerations Section in RFCs", RFC 8126, 375 June 2017. 377 [RFC3945] Mannie, E., "Generalized Multi-Protocol Label Switching 378 (GMPLS) Architecture", RFC 3945, October 2004. 380 [RFC5920] Fang, L., "Security Framework for MPLS and GMPLS 381 Networks", RFC 5920, July 2010. 383 [G.827] ITU-T Recommendation, "Availability performance parameters 384 and objectives for end-to-end international constant bit- 385 rate digital paths", September 2003. 387 [F.1703] ITU-R Recommendation, "Availability objectives for real 388 digital fixed wireless links used in 27 500 km 389 hypothetical reference paths and connections", January 390 2005. 392 [P.530] ITU-R Recommendation," Propagation data and prediction 393 methods required for the design of terrestrial line-of- 394 sight systems", February 2012 396 [EN 302 217] ETSI standard, "Fixed Radio Systems; Characteristics 397 and requirements for point-to-point equipment and 398 antennas", April 2009 400 [RFC8330] H., Long, M., Ye, Mirsky, G., Alessandro, A., Shah, H., 401 "OSPF Traffic Engineering (OSPF-TE) Link Availability 402 Extension for Links with Variable Discrete Bandwidth", 403 RFC8330, February 2018 405 7. Appendix: Bandwidth Availability Example 407 In a mobile backhaul network, microwave links are very popular for 408 providing connections of last hops. In case of heavy rain 409 conditions, to maintain the link connectivity, the microwave link 410 may lower the modulation level since moving to a lower modulation 411 level provides for a lower Signal-to-Noise Ratio (SNR) requirement. 412 This is called adaptive modulation technology [EN 302 217]. However, 413 a lower modulation level also means lower link bandwidth. When link 414 bandwidth is reduced because of modulation down-shifting, high- 415 priority traffic can be maintained, while lower-priority traffic is 416 dropped. Similarly, copper links may change their link bandwidth due 417 to external interference. 419 Presuming that a link has three discrete bandwidth levels: 421 The link bandwidth under modulation level 1, e.g., QPSK, is 100 422 Mbps; 424 The link bandwidth under modulation level 2, e.g., 16QAM, is 200 425 Mbps; 427 The link bandwidth under modulation level 3, e.g., 256QAM, is 400 428 Mbps. 430 On a sunny day, the modulation level 3 can be used to achieve 400 431 Mbps link bandwidth. 433 A light rain with X mm/h rate triggers the system to change the 434 modulation level from level 3 to level 2, with bandwidth changing 435 from 400 Mbps to 200 Mbps. The probability of X mm/h rain in the 436 local area is 52 minutes in a year. Then the dropped 200 Mbps 437 bandwidth has 99.99% availability. 439 A heavy rain with Y(Y>X) mm/h rate triggers the system to change the 440 modulation level from level 2 to level 1, with bandwidth changing 441 from 200 Mbps to 100 Mbps. The probability of Y mm/h rain in the 442 local area is 26 minutes in a year. Then the dropped 100 Mbps 443 bandwidth has 99.995% availability. 445 For the 100M bandwidth of the modulation level 1, only the extreme 446 weather condition can cause the whole system to be unavailable, 447 which only happens for 5 minutes in a year. So the 100 Mbps 448 bandwidth of the modulation level 1 owns the availability of 449 99.999%. 451 There are discrete buckets per availability level. Under the worst 452 weather conditions, there's only 100 Mbps capacity and that's 453 99.999% available. It's treated as effectively "always available" 454 since there's no way to do any better. If the weather is bad but not 455 the worst weather, modulation level 2 can be used, which gets an 456 additional 100 Mbps bandwidth (i.e., 200 Mbps total), so there are 457 100 Mbps in the 99.999% bucket and 100 Mbps in the 99.995% bucket. 458 In clear weather, modulate level 3 can be used to get 400 Mbps 459 total, but that's only 200 Mbps more than at modulation level 2, so 460 99.99% bucket has that "extra" 200 Mbps, and the other two buckets 461 still have their 100 Mbps each. 463 Therefore, the maximum bandwidth is 400 Mbps. According to the 464 weather condition, the sub-bandwidth and its availability are shown 465 as follows: 467 Sub-bandwidth (Mbps) Availability 469 ------------------ ------------ 471 200 99.99% 473 100 99.995% 475 100 99.999% 477 8. Acknowledgments 479 The authors would like to thank Deborah Brungard, Khuzema Pithewan, 480 Lou Berger, Yuji Tochio, Dieter Beller, and Autumn Liu for their 481 comments and contributions on the document. 483 Authors' Addresses 485 Hao Long 486 Huawei Technologies Co., Ltd. 487 No.1899, Xiyuan Avenue, Hi-tech Western District 488 Chengdu 611731, P.R.China 490 Phone: +86-18615778750 491 Email: longhao@huawei.com 493 Min Ye (editor) 494 Huawei Technologies Co., Ltd. 495 No.1899, Xiyuan Avenue, Hi-tech Western District 496 Chengdu 611731, P.R.China 498 Email: amy.yemin@huawei.com 500 Greg Mirsky (editor) 501 ZTE 503 Email: gregimirsky@gmail.com 505 Alessandro D'Alessandro 506 Telecom Italia S.p.A 508 Email: alessandro.dalessandro@telecomitalia.it 510 Himanshu Shah 511 Ciena Corp. 512 3939 North First Street 513 San Jose, CA 95134 514 US 516 Email: hshah@ciena.com