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Tarapore 6 C. Dvorak 7 AT&T Labs 8 Y. El Mghazli 9 Alcatel-Lucent 10 January 6, 2010 12 Y.1541-QOSM -- Y.1541 QoS Model for Networks Using Y.1541 QoS Classes 13 draft-ietf-nsis-y1541-qosm-08 15 Abstract 17 This draft describes a QoS-NSLP QoS model (QOSM) based on ITU-T 18 Recommendation Y.1541 Network QoS Classes and related signaling 19 requirements. Y.1541 specifies 8 classes of Network Performance 20 objectives, and the Y.1541-QOSM extensions include additional QSPEC 21 parameters and QOSM processing guidelines. 23 Requirements Language 25 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 26 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this 27 document are to be interpreted as described in RFC 2119 [RFC2119]. 29 Status of this Memo 31 This Internet-Draft is submitted to IETF in full conformance with the 32 provisions of BCP 78 and BCP 79. 34 Internet-Drafts are working documents of the Internet Engineering 35 Task Force (IETF), its areas, and its working groups. Note that 36 other groups may also distribute working documents as Internet- 37 Drafts. 39 Internet-Drafts are draft documents valid for a maximum of six months 40 and may be updated, replaced, or obsoleted by other documents at any 41 time. It is inappropriate to use Internet-Drafts as reference 42 material or to cite them other than as "work in progress." 44 The list of current Internet-Drafts can be accessed at 45 http://www.ietf.org/ietf/1id-abstracts.txt. 47 The list of Internet-Draft Shadow Directories can be accessed at 48 http://www.ietf.org/shadow.html. 50 This Internet-Draft will expire on July 10, 2010. 52 Copyright Notice 54 Copyright (c) 2010 IETF Trust and the persons identified as the 55 document authors. All rights reserved. 57 This document is subject to BCP 78 and the IETF Trust's Legal 58 Provisions Relating to IETF Documents 59 (http://trustee.ietf.org/license-info) in effect on the date of 60 publication of this document. Please review these documents 61 carefully, as they describe your rights and restrictions with respect 62 to this document. Code Components extracted from this document must 63 include Simplified BSD License text as described in Section 4.e of 64 the Trust Legal Provisions and are provided without warranty as 65 described in the BSD License. 67 This document may contain material from IETF Documents or IETF 68 Contributions published or made publicly available before November 69 10, 2008. The person(s) controlling the copyright in some of this 70 material may not have granted the IETF Trust the right to allow 71 modifications of such material outside the IETF Standards Process. 72 Without obtaining an adequate license from the person(s) controlling 73 the copyright in such materials, this document may not be modified 74 outside the IETF Standards Process, and derivative works of it may 75 not be created outside the IETF Standards Process, except to format 76 it for publication as an RFC or to translate it into languages other 77 than English. 79 Table of Contents 81 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 82 2. Summary of ITU-T Recommendations Y.1541 & Signaling 83 Requirements . . . . . . . . . . . . . . . . . . . . . . . . . 3 84 2.1. Y.1541 Classes . . . . . . . . . . . . . . . . . . . . . . 3 85 2.2. Y.1541-QOSM Processing Requirements . . . . . . . . . . . 5 86 3. Additional QSPEC Parameters for Y.1541 QOSM . . . . . . . . . 6 87 3.1. Traffic Model (TMOD) Extension Parameter . . . . . . . . . 7 88 3.2. Restoration Priority Parameter . . . . . . . . . . . . . . 7 89 4. Y.1541-QOSM Considerations and Processing Example . . . . . . 9 90 4.1. Deployment Considerations . . . . . . . . . . . . . . . . 9 91 4.2. Applicable QSPEC Procedures . . . . . . . . . . . . . . . 9 92 4.3. QNE Processing Rules . . . . . . . . . . . . . . . . . . . 10 93 4.4. Processing Example . . . . . . . . . . . . . . . . . . . . 10 94 4.5. Bit-Level QSPEC Example . . . . . . . . . . . . . . . . . 12 95 4.6. Preemption Behaviour . . . . . . . . . . . . . . . . . . . 13 96 5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 14 97 5.1. Assignment of QSPEC Parameter IDs . . . . . . . . . . . . 14 98 5.2. Restoration Priority Parameter Registry . . . . . . . . . 14 99 5.2.1. Restoration Priority Field . . . . . . . . . . . . . . 14 100 5.2.2. Time to Restore Field . . . . . . . . . . . . . . . . 15 101 5.2.3. Extent of Restoration Field . . . . . . . . . . . . . 15 102 5.2.4. Reserved Bits . . . . . . . . . . . . . . . . . . . . 15 103 6. Security Considerations . . . . . . . . . . . . . . . . . . . 16 104 7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 16 105 8. References . . . . . . . . . . . . . . . . . . . . . . . . . . 16 106 8.1. Normative References . . . . . . . . . . . . . . . . . . . 16 107 8.2. Informative References . . . . . . . . . . . . . . . . . . 17 108 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 18 110 1. Introduction 112 This draft describes a QoS model (QOSM) for NSIS QoS signaling layer 113 protocol (QoS-NSLP) application based on ITU-T Recommendation Y.1541 114 Network QoS Classes and related signaling requirements. [Y.1541] 115 currently specifies 8 classes of Network Performance objectives, and 116 the Y.1541-QOSM extensions include additional QSPEC parameters and 117 QOSM processing guidelines. The extensions are based on 118 standardization work in the ITU-T on QoS signaling requirements 119 [Y.1541] [TRQ-QoS-SIG] [E.361]. 121 [I-D.ietf-nsis-qos-nslp] defines message types and control 122 information for the QoS-NSLP generic to all QOSMs. A QOSM is a 123 defined mechanism for achieving QoS as a whole. The specification of 124 a QOSM includes a description of its QSPEC parameter information, as 125 well as how that information should be treated or interpreted in the 126 network. The QSPEC [I-D.ietf-nsis-qspec] contains a set of 127 parameters and values describing the requested resources. It is 128 opaque to the QoS-NSLP and similar in purpose to the TSpec, RSpec and 129 AdSpec specified in [RFC2205] [RFC2210] . The QSPEC object contains 130 the QoS parameters defined by the QOSM. A QOSM provides a specific 131 set of parameters to be carried in the QSPEC. At each QoS NSIS 132 element (QNE), the QSPEC contents are interpreted by the resource 133 management function (RMF) for purposes of policy control and traffic 134 control, including admission control and configuration of the 135 scheduler. 137 2. Summary of ITU-T Recommendations Y.1541 & Signaling Requirements 139 As stated above, [Y.1541] is a specification of standardized QoS 140 classes for IP networks (a summary of these classes is given below). 141 Section 7 of [TRQ-QoS-SIG] specifies signaling features needed to 142 achieve end-to-end QoS in IP networks, with Y.1541 QoS classes as a 143 basis. [Y.1541] recommends a flexible allocation of the end-to-end 144 performance objectives (e.g., delay) across networks, rather than a 145 fixed per-network allocation. NSIS protocols already address most of 146 the requirements, this document identifies additional QSPEC 147 parameters and processing requirements needed to support the Y.1541 148 QOSM. 150 2.1. Y.1541 Classes 152 [Y.1541] proposes grouping services into QoS classes defined 153 according to the desired QoS performance objectives. These QoS 154 classes support a wide range of user applications. The classes group 155 objectives for one-way IP packet delay, IP packet delay variation, IP 156 packet loss ratio, etc., where the parameters themselves are defined 157 in [Y.1540]. Classes 0 and 1 might be implemented using the DiffServ 158 EF PHB, and support interactive real-time applications. Classes 2, 159 3, and 4 might be implemented using the DiffServ AFxy PHB Group, and 160 support data transfer applications with various degrees of 161 interactivity. Class 5 generally corresponds to the DiffServ Default 162 PHB, has all the QoS parameters unspecified consistent with a best- 163 effort service. Classes 6 and 7 provide support for extremely loss- 164 sensitive user applications, such as high quality digital television, 165 TDM circuit emulation, and high capacity file transfers using TCP. 166 These classes are intended to serve as a basis for agreements between 167 end-users and service providers, and between service providers. They 168 support a wide range of user applications including point-to-point 169 telephony, data transfer, multimedia conferencing, and others. The 170 limited number of classes supports the requirement for feasible 171 implementation, particularly with respect to scale in global 172 networks. 174 The QoS classes apply to a packet flow, where [Y.1541] defines a 175 packet flow as the traffic associated with a given connection or 176 connectionless stream having the same source host, destination host, 177 class of service, and session identification. The characteristics of 178 each Y.1451 QoS class are summarized here: 180 Class 0: Real-time, highly interactive applications, sensitive to 181 jitter. Mean delay upper bound is 100 ms, delay variation is less 182 than 50 ms, and loss ratio is less than 10^-3. Application examples 183 include VoIP, Video Teleconference. 185 Class 1: Real-time, interactive applications, sensitive to jitter. 186 Mean delay upper bound is 400 ms, delay variation is less than 50 ms, 187 and loss ratio is less than 10^-3. Application examples include 188 VoIP, video teleconference. 190 Class 2: Highly interactive transaction data. Mean delay upper bound 191 is 100 ms, delay variation is unspecified, and loss ratio is less 192 than 10^-3. Application examples include signaling. 194 Class 3: Interactive transaction data. Mean delay upper bound is 400 195 ms, delay variation is unspecified, and loss ratio is less than 196 10^-3. Application examples include signaling. 198 Class 4: Low Loss Only applications. Mean delay upper bound is 1s, 199 delay variation is unspecified, and loss ratio is less than 10^-3. 200 Application examples include short transactions, bulk data, video 201 streaming 203 Class 5: Unspecified applications with unspecified mean delay, delay 204 variation, and loss ratio. Application examples include traditional 205 applications of Default IP Networks 207 Class 6: Mean delay <= 100 ms, delay variation <= 50 ms, loss ratio 208 <= 10^-5. Applications that are highly sensitive to loss, such as 209 television transport, high-capacity TCP transfers, and TDM circuit 210 emulation. 212 Class 7: Mean delay <= 400 ms, delay variation <= 50 ms, loss ratio 213 <= 10^-5. Applications that are highly sensitive to loss, such as 214 television transport, high-capacity TCP transfers, and TDM circuit 215 emulation. 217 These classes enable SLAs to be defined between customers and network 218 service providers with respect to QoS requirements. The service 219 provider then needs to ensure that the requirements are recognized 220 and receive appropriate treatment across network layers. 222 Work is in progress to specify methods for combining local values of 223 performance metrics to estimate the performance of the complete path. 224 See section 8 of [Y.1541], [I-D.ietf-ippm-framework-compagg], and 225 [I-D.ietf-ippm-spatial-composition]. 227 2.2. Y.1541-QOSM Processing Requirements 229 [TRQ-QoS-SIG] provides the requirements for signaling information 230 regarding IP-based QoS at the interface between the user and the 231 network (UNI) and across interfaces between different networks (NNI). 232 To meet specific network performance requirements specified for the 233 Y.1541 QoS classes [Y.1541] , a network needs to provide specific 234 user plane functionality at UNI and NNI interfaces. Dynamic network 235 provisioning at a UNI and/or NNI node allows the ability to 236 dynamically request a traffic contract for an IP flow from a specific 237 source node to one or more destination nodes. In response to the 238 request, the network determines if resources are available to satisfy 239 the request and provision the network. 241 For implementations to claim compliance with this memo, it MUST be 242 possible to derive the following service level parameters as part of 243 the process of requesting service: 245 a. Y.1541 QoS class, 32 bit integer, range : 0-7 247 b. rate (r), octets per second 249 c. peak rate (p), octets per second 251 d. bucket size (b), octets 252 e. maximum packet size (M), octets, IP header + IP payload 254 f. DiffServ PHB class [RFC2475] 256 g. admission priority, 32 bit integer, range : 0-2 258 Compliant implementations MAY derive the following service level 259 parameters as part of the service request process: 261 h. peak bucket size (Bp)*, octets, 32 bit floating point number in 262 single-precision IEEE floating point format [IEEE754] 264 i. restoration priority*, multiple integer values defined in Section 265 3 below 267 All parameters except Bp and restoration priority have already been 268 specified in [I-D.ietf-nsis-qspec]. These additional parameters are 269 defined as 271 o Bp, The size of the peak-rate bucket in a dual token bucket 272 arrangement, essentially setting the maximum length of bursts in 273 the peak-rate stream. For example, see Annex B of [Y.1221] 275 o restoration priority, as defined in Section 3 of this memo 277 and their QSPEC Parameter format is specified in Section 3. 279 It MUST be possible to perform the following QoS-NSLP signaling 280 functions to meet Y.1541-QOSM requirements: 282 a. accumulate delay, delay variation and loss ratio across the end- 283 to-end connection, which may span multiple domains 285 b. enable negotiation of Y.1541 QoS class across domains. 287 c. enable negotiation of delay, delay variation, and loss ratio 288 across domains. 290 These signaling requirements are supported in 291 [I-D.ietf-nsis-qos-nslp] and the functions are illustrated in Section 292 4 of this memo. 294 3. Additional QSPEC Parameters for Y.1541 QOSM 295 3.1. Traffic Model (TMOD) Extension Parameter 297 The traffic model (TMOD) extension parameter is represented by one 298 floating point number in single-precision IEEE floating point format 299 and one 32-bit reserved field. 301 0 1 2 3 302 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 1 303 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 304 |M|E|N|r| 15 |r|r|r|r| 2 | 305 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 306 | Peak Bucket Size [Bp] (32-bit IEEE floating point number) | 307 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 308 | Reserved | 309 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 311 Figure 1: TMOD Extension 313 The Peak Bucket Size term, Bp, is represented as an IEEE floating 314 point value [IEEE754] in units of octets. The sign bit MUST be zero 315 (all values MUST be non-negative). Exponents less than 127 (i.e., 0) 316 are prohibited. Exponents greater than 162 (i.e., positive 35) are 317 discouraged, except for specifying a peak rate of infinity. Infinity 318 is represented with an exponent of all ones (255) and a sign bit and 319 mantissa of all zeros. 321 Reserved: These 4 octets are reserved. The Reserved octets MAY be 322 designated for other uses in the future. Senders conforming to this 323 version of the Y.1541 QOSM SHALL set the Reserved octets to zero. 324 Receivers conforming to this version of the Y.1541 QOSM SHALL ignore 325 the Reserved octets. 327 The QSPEC parameter behavior for the TMOD extended parameter is 328 similar to that defined in Section 3.3.1 of[I-D.ietf-nsis-qspec]. 329 The new parameter (and all traffic-related parameters) are specified 330 independently from the Y.1541 class parameter. 332 3.2. Restoration Priority Parameter 334 Restoration priority is the urgency with which a service requires 335 successful restoration under failure conditions. Restoration 336 priority is achieved by provisioning sufficient backup capacity, as 337 necessary, and allowing relative priority for access to available 338 bandwidth when there is contention for restoration bandwidth. 339 Restoration priority is defined as follows: 341 0 1 2 3 342 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 1 343 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 344 |M|E|N|r| 16 |r|r|r|r| 1 | 345 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 346 | Rest. Priority| TTR | EOR | (Reserved) | 347 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 349 Figure 2: Restoration Priority Parameter 351 This parameter has three fields and a reserved area, as defined 352 below. 354 Restoration Priority Field (8-bit unsigned integer): 3 priority 355 values are listed here in the order of lowest priority to highest 356 priority: 358 0 - best effort 360 1 - normal 362 2 - high 364 These priority values are described in [Y.2172], where best effort 365 priority is the same as Priority level 3, normal priority is Priority 366 level 2, and high priority is the same as Priority level 1. There 367 are several ways to elaborate on restoration priority, and the two 368 current parameters are described below. 370 Time-to-Restore (TTR) Field (4-bit unsigned integer): Total amount of 371 time to restore traffic streams belonging to a given restoration 372 class impacted by the failure. This time period depends on the 373 technology deployed for restoration. A fast recovery period of < 200 374 ms is based on current experience with SONET rings and a slower 375 recovery period of 2 seconds is suggested in order to enable a voice 376 call to recover without being dropped. Accordingly, TTR restoration 377 suggested ranges are: 379 0 - Unspecified Time-to-Restore 381 1 - Best Time-to-Restore: <= 200 ms 383 2 - Normal Time-to-Restore <= 2 s 385 Extent of Restoration (EOR) Field (4-bit unsigned integer): 386 Percentage of traffic belonging to the restoration class that can be 387 restored. This percentage depends on the amount of spare capacity 388 engineered. All high priority restoration priority traffic, for 389 example, may be "guaranteed" at 100% by the service provider. Other 390 classes may offer lesser chances for successful restoration. The 391 restoration extent for these lower priority classes depend on SLA 392 agreements developed between the service provider and the customer. 394 EOR values are assigned as follows: 396 0 - unspecified EOR 398 1 - high priority restored at 100%; medium priority restored at 100% 400 2 - high priority restored at 100%; medium priority restored at 80% 402 3 - high priority restored >= 80%; medium priority restored >= 80% 404 4 - high priority restored >= 80%; medium priority restored >= 60% 406 5 - high priority restored >= 60%; medium priority restored >= 60% 408 Reserved: These 2 octets are reserved. The Reserved bits MAY be 409 designated for other uses in the future. Senders conforming to this 410 version of the Y.1541 QOSM SHALL set the Reserved bits to zero. 411 Receivers conforming to this version of the Y.1541 QOSM SHALL ignore 412 the Reserved bits. 414 4. Y.1541-QOSM Considerations and Processing Example 416 In this Section we illustrate the operation of the Y.1541 QOSM, and 417 show how current QoS-NSLP and QSPEC functionality is used. No new 418 processing capabilities are required to enable the Y.1541 QOSM 419 (excluding the two OPTIONAL new parameters specified in Section 3). 421 4.1. Deployment Considerations 423 [TRQ-QoS-SIG] emphasizes the deployment of Y.1541 QNEs at the borders 424 of supporting domains. There may be domain configurations where 425 interior QNEs are desirable, and the example below addresses this 426 possibility. 428 QNEs may be Stateful in some limited aspects, but obviously it is 429 preferable to deploy stateless QNEs. 431 4.2. Applicable QSPEC Procedures 433 All procedures defined in section 5.3 of [I-D.ietf-nsis-qspec] are 434 applicable to this QOSM. 436 4.3. QNE Processing Rules 438 Section 7 of [TRQ-QoS-SIG] describes the information processing in 439 Y.1541 QNEs. 441 Section 8 of [Y.1541] defines the accumulation rules for individual 442 performance parameters (e.g., delay, jitter). 444 When a QNI specifies the Y.1541 QoS Class number, , 445 it is a sufficient specification of objectives for the , , and parameters. As described 447 above in section 2, some Y.1541 Classes do not set objectives for all 448 the performance parameters above. For example, Classes 2, 3, and 4, 449 do not specify an objective for (referred to as IP 450 Packet Delay Variation). In the case that the QoS Class leaves a 451 parameter Unspecified, then that parameter need not be included in 452 the accumulation processing. 454 4.4. Processing Example 456 As described in the example given in Section 4.4 of 457 [I-D.ietf-nsis-qspec] and as illustrated in Figure 3, the QoS NSIS 458 initiator (QNI) initiates an end-to-end, inter-domain QoS NSLP 459 RESERVE message containing the Initiator QSPEC. In the case of the 460 Y.1541 QOSM, the Initiator QSPEC specifies the , 461 , , , , and perhaps other QSPEC parameters for the flow. As 463 described in Section 3, the TMOD extension parameter contains the 464 OPTIONAL, Y.1541-QOSM-specific terms; restoration priority is also an 465 OPTIONAL, Y.1541-QOSM-specific parameter. 467 As Figure 3 below shows, the RESERVE message may cross multiple 468 domains supporting different QOSMs. In this illustration, the 469 initiator QSPEC arrives in an QoS NSLP RESERVE message at the ingress 470 node of the local-QOSM domain. As described in 471 [I-D.ietf-nsis-qos-nslp] and [I-D.ietf-nsis-qspec], at the ingress 472 edge node of the local-QOSM domain, the end-to-end, inter-domain QoS- 473 NSLP message may trigger the generation of a local QSPEC, and the 474 initiator QSPEC encapsulated within the messages signaled through the 475 local domain. The local QSPEC is used for QoS processing in the 476 local-QOSM domain, and the Initiator QSPEC is used for QoS processing 477 outside the local domain. As specified in [I-D.ietf-nsis-qspec], if 478 any QNE cannot meet the requirements designated by the initiator 479 QSPEC to support an optional QSPEC parameter, with the M bit set to 480 zero for the parameter, for example, it cannot support the 481 accumulation of end-to-end delay with the parameter, 482 the QNE sets the N flag (not supported flag) for the path latency 483 parameter to one. 485 Also, the Y.1541-QOSM requires negotiation of the 486 across domains. This negotiation can be done with the use of the 487 existing procedures already defined in [I-D.ietf-nsis-qos-nslp]. For 488 example, the QNI sets , , 489 objects to include , which specifies objectives for 490 the , , parameters. In the 491 case that the QoS Class leaves a parameter Unspecified, then that 492 parameter need not be included in the accumulation processing. The 493 QNE/domain SHOULD set the Y.1541 class and cumulative parameters, 494 e.g., , that can be achieved in the 495 object (but not less than specified in ). This could 496 include, for example, setting the to a lower class 497 than specified in (but not lower than specified in 498 ). If the fails to satisfy one or more 499 of the objectives, the QNE/domain notifies the QNI and 500 the reservation is aborted. Otherwise, the QNR notifies the QNI of 501 the for the reservation. 503 When the available must be reduced from the 504 desired , say because the delay objective has been 505 exceeded, then there is an incentive to respond with an available 506 value for delay in the parameter. If the available 507 is 150 ms (still useful for many applications) and the 508 desired QoS is Class 0 (with its 100 ms objective), then the response 509 would be that Class 0 cannot be achieved and Class 1 is available 510 (with its 400 ms objective). In addition, this QOSM allows the 511 response to include an available = 150 ms, making 512 acceptance of the available more likely. There 513 are many long paths where the propagation delay alone exceeds the 514 Y.1541 Class 0 objective, so this feature adds flexibility to commit 515 to exceed the Class 1 objective when possible. 517 This example illustrates Y.1541-QOSM negotiation of and cumulative parameter values that can be achieved end-to- 519 end. The example illustrates how the QNI can use the cumulative 520 values collected in to decide if a lower than specified in is acceptable. 523 |------| |------| |------| |------| 524 | e2e |<->| e2e |<------------------------->| e2e |<->| e2e | 525 | QOSM | | QOSM | | QOSM | | QOSM | 526 | | |------| |-------| |-------| |------| | | 527 | NSLP | | NSLP |<->| NSLP |<->| NSLP |<->| NSLP | | NSLP | 528 |Y.1541| |local | |local | |local | |local | |Y.1541| 529 | QOSM | | QOSM | | QOSM | | QOSM | | QOSM | | QOSM | 530 |------| |------| |-------| |-------| |------| |------| 531 ----------------------------------------------------------------- 532 |------| |------| |-------| |-------| |------| |------| 533 | NTLP |<->| NTLP |<->| NTLP |<->| NTLP |<->| NTLP |<->| NTLP | 534 |------| |------| |-------| |-------| |------| |------| 535 QNI QNE QNE QNE QNE QNR 536 (End) (Ingress Edge) (Interior) (Interior) (Egress Edge) (End) 538 Figure 3: Example of Y.1541-QOSM Operation 540 4.5. Bit-Level QSPEC Example 542 This is an example where the QOS Desired specification contains the 543 TMOD-1 parameters and TMOD extended parameters defined in this 544 specification, as well as the Y.1541 Class parameter. The QOS 545 Available specification utilizes the Latency, Jitter, and Loss 546 parameters to enable accumulation of these parameters for easy 547 comparison with the objectives desired fir the Y.1541 Class. 549 This example assumes that all the parameters MUST be supported by the 550 QNEs, so all M-flags have been set to "1". 552 0 1 2 3 553 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 1 554 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 555 | Vers.|QType=I|QSPEC Proc.=0/1|0|R|R|R| Length = 24 | 556 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 557 |E|r|r|r| Type = 0 (QoS Des.) |r|r|r|r| Length = 11 | 558 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 559 |1|E|0|r| ID = 1 |r|r|r|r| Length = 5 | 560 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 561 | TMOD Rate-1 [r] (32-bit IEEE floating point number) | 562 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 563 | TMOD Size-1 [b] (32-bit IEEE floating point number) | 564 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 565 | Peak Data Rate-1 [p] (32-bit IEEE floating point number) | 566 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 567 | Minimum Policed Unit-1 [m] (32-bit unsigned integer) | 568 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 569 | Maximum Packet Size [M] (32-bit unsigned integer) | 570 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 571 |1|E|N|r| 15 |r|r|r|r| 2 | 572 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 573 | Peak Bucket Size [Bp] (32-bit IEEE floating point number) | 574 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 575 | Reserved | 576 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 577 |1|E|N|r| 14 |r|r|r|r| 1 | 578 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 579 |Y.1541 QoS Cls.| (Reserved) | 580 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 581 |E|r|r|r| Type = 1 (QoS Avail) |r|r|r|r| Length = 11 | 582 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 583 |1|E|N|r| 3 |r|r|r|r| 1 | 584 +---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+ 585 | Path Latency (32-bit integer) | 586 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 587 |1|E|N|r| 4 |r|r|r|r| 4 | 588 +---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+ 589 | Path Jitter STAT1(variance) (32-bit integer) | 590 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 591 | Path Jitter STAT2(99.9%-ile) (32-bit integer) | 592 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 593 | Path Jitter STAT3(minimum Latency) (32-bit integer) | 594 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 595 | Path Jitter STAT4(Reserved) (32-bit integer) | 596 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 597 |1|E|N|r| 5 |r|r|r|r| 1 | 598 +---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+ 599 | Path Packet Loss Ratio (32-bit floating point) | 600 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 601 |1|E|N|r| 14 |r|r|r|r| 1 | 602 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 603 |Y.1541 QoS Cls.| (Reserved) | 604 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 606 Figure 4: An Example QSPEC (Initiator) 608 where 32-bit floating point numbers are as specified in [IEEE754]. 610 4.6. Preemption Behaviour 612 The default QNI behaviour of tearing down a preempted reservation is 613 followed in the Y.1541 QOSM. The restoration priority parameter 614 described above does not rely on preemption. 616 5. IANA Considerations 618 This section defines additional codepoint assignments in the QSPEC 619 Parameter ID registry and requests the establishment of one new 620 registry for the Restoration Priority Parameter (and assigns initial 621 values), in accordance with BCP 26 [RFC5226]. It also defines the 622 procedural requirements to be followed by IANA in allocating new 623 codepoints for the new Registry. 625 5.1. Assignment of QSPEC Parameter IDs 627 This document specifies the following QSPEC parameters to be assigned 628 within the QSPEC Parameter ID registry created in 629 [I-D.ietf-nsis-qspec]: 631 parameter (Section 3.1 above, suggested ID=15) 633 parameter (Section 3.2 above, suggested ID=16) 635 5.2. Restoration Priority Parameter Registry 637 The Registry for Restoration Priority contains assignments for three 638 fields in the 4 octet word, and a Reserved section of the word. 640 This specification creates the following registry with the structure 641 as defined below: 643 5.2.1. Restoration Priority Field 645 The Restoration Priority Field is 8 bits in length. 647 The following values are allocated by this specification: 649 0-2: assigned as specified in Section 3.2: 651 0: best-effort priority 653 1: normal priority 655 2: high priority 657 The allocation policies for further values are as follows: 659 3-63: Specification Required 661 5.2.2. Time to Restore Field 663 The Time to Restore Field is 4 bits in length. 665 The following values are allocated by this specification: 667 0-2: assigned as specified in Section 3.2: 669 0 - Unspecified Time-to-Restore 671 1 - Best Time-to-Restore: <= 200 ms 673 2 - Normal Time-to-Restore <= 2 s 675 The allocation policies for further values are as follows: 677 3-15: Specification Required 679 5.2.3. Extent of Restoration Field 681 The Extent of Restoration (EOR) Field is 4 bits in length. 683 The following values are allocated by this specification: 685 0-5: assigned as specified in Section 3.2: 687 EOR values are assigned as follows: 689 0 - unspecified EOR 691 1 - high priority restored at 100%; medium priority restored at 100% 693 2 - high priority restored at 100%; medium priority restored at 80% 695 3 - high priority restored >= 80%; medium priority restored >= 80% 697 4 - high priority restored >= 80%; medium priority restored >= 60% 699 5 - high priority restored >= 60%; medium priority restored >= 60% 701 The allocation policies for further values are as follows: 703 6-15: Specification Required 705 5.2.4. Reserved Bits 707 The remaining bits in the Restoration Priority Parameter are 708 Reserved. The Reserved bits MAY be designated for other uses in the 709 future. 711 6. Security Considerations 713 The security considerations of [I-D.ietf-nsis-qos-nslp] and 714 [I-D.ietf-nsis-qspec] apply to this Document. 716 The restoration priority parameter raises possibilities for theft of 717 service attacks because users could claim an emergency priority for 718 their flows without real need, thereby effectively preventing serious 719 emergency calls to get through. Several options exist for countering 720 such attacks, for example 722 - only some user groups (e.g. the police) are authorized to set the 723 emergency priority bit 725 - any user is authorized to employ the emergency priority bit for 726 particular destination addresses (e.g. police or fire departments) 728 There are no other known security considerations based on this 729 document. 731 7. Acknowledgements 733 The authors thank Attila Bader, Cornelia Kappler, Sven Van den Bosch, 734 and Hannes Tschofenig for helpful comments and discussion. 736 8. References 738 8.1. Normative References 740 [I-D.ietf-nsis-qos-nslp] 741 Manner, J., Karagiannis, G., and A. McDonald, "NSLP for 742 Quality-of-Service Signaling", draft-ietf-nsis-qos-nslp-17 743 (work in progress), October 2009. 745 [I-D.ietf-nsis-qspec] 746 Bader, A., Ash, G., Kappler, C., and D. Oran, "QoS NSLP 747 QSPEC Template", draft-ietf-nsis-qspec-22 (work in 748 progress), November 2009. 750 [IEEE754] ANSI/IEEE, "ANSI/IEEE 754-1985, IEEE Standard for Binary 751 Floating-Point Arithmetic", 1985. 753 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 754 Requirement Levels", BCP 14, RFC 2119, March 1997. 756 [TRQ-QoS-SIG] 757 ITU-T Supplement 51 to the Q-Series, "Signaling 758 Requirements for IP-QoS", January 2004. 760 [Y.1221] ITU-T Recommendation Y.1541, "Traffic control and 761 congestion control in IP based networks", March 2002. 763 [Y.1540] ITU-T Recommendation Y.1540, "Internet protocol data 764 communication service - IP packet transfer and 765 availability performance parameters", December 2007. 767 [Y.1541] ITU-T Recommendation Y.1541, "Network Performance 768 Objectives for IP-Based Services", February 2006. 770 [Y.2172] ITU-T Recommendation Y.1540, "Service restoration priority 771 levels in Next Generation Networks", June 2007. 773 8.2. Informative References 775 [E.361] ITU-T Recommendation E.361, "QoS Routing Support for 776 Interworking of QoS Service Classes Across Routing 777 Technologies", May 2003. 779 [I-D.ietf-ippm-framework-compagg] 780 Morton, A., "Framework for Metric Composition", 781 draft-ietf-ippm-framework-compagg-09 (work in progress), 782 December 2009. 784 [I-D.ietf-ippm-spatial-composition] 785 Morton, A. and E. Stephan, "Spatial Composition of 786 Metrics", draft-ietf-ippm-spatial-composition-10 (work in 787 progress), October 2009. 789 [RFC2205] Braden, B., Zhang, L., Berson, S., Herzog, S., and S. 790 Jamin, "Resource ReSerVation Protocol (RSVP) -- Version 1 791 Functional Specification", RFC 2205, September 1997. 793 [RFC2210] Wroclawski, J., "The Use of RSVP with IETF Integrated 794 Services", RFC 2210, September 1997. 796 [RFC2475] Blake, S., Black, D., Carlson, M., Davies, E., Wang, Z., 797 and W. Weiss, "An Architecture for Differentiated 798 Services", RFC 2475, December 1998. 800 [RFC5226] Narten, T. and H. Alvestrand, "Guidelines for Writing an 801 IANA Considerations Section in RFCs", BCP 26, RFC 5226, 802 May 2008. 804 Authors' Addresses 806 Jerry Ash 807 AT&T Labs 808 200 Laurel Avenue South 809 Middletown,, NJ 07748 810 USA 812 Phone: 813 Fax: 814 Email: gash5107@yahoo.com 815 URI: 817 Al Morton 818 AT&T Labs 819 200 Laurel Avenue South 820 Middletown,, NJ 07748 821 USA 823 Phone: +1 732 420 1571 824 Fax: +1 732 368 1192 825 Email: acmorton@att.com 826 URI: http://home.comcast.net/~acmacm/ 828 Martin Dolly 829 AT&T Labs 830 200 Laurel Avenue South 831 Middletown,, NJ 07748 832 USA 834 Phone: 835 Fax: 836 Email: mdolly@att.com 837 URI: 839 Percy Tarapore 840 AT&T Labs 841 200 Laurel Avenue South 842 Middletown,, NJ 07748 843 USA 845 Phone: 846 Fax: 847 Email: tarapore@att.com 848 URI: 850 Chuck Dvorak 851 AT&T Labs 852 180 Park Ave Bldg 2 853 Florham Park,, NJ 07932 854 USA 856 Phone: + 1 973-236-6700 857 Fax: 858 Email: cdvorak@att.com 859 URI: http: 861 Yacine El Mghazli 862 Alcatel-Lucent 863 Route de Nozay 864 Marcoussis cedex, 91460 865 France 867 Phone: +33 1 69 63 41 87 868 Fax: 869 Email: yacine.el_mghazli@alcatel.fr 870 URI: