idnits 2.17.1 draft-ietf-pce-stateful-pce-auto-bandwidth-00.txt: Checking boilerplate required by RFC 5378 and the IETF Trust (see https://trustee.ietf.org/license-info): ---------------------------------------------------------------------------- No issues found here. Checking nits according to https://www.ietf.org/id-info/1id-guidelines.txt: ---------------------------------------------------------------------------- No issues found here. Checking nits according to https://www.ietf.org/id-info/checklist : ---------------------------------------------------------------------------- No issues found here. Miscellaneous warnings: ---------------------------------------------------------------------------- == The copyright year in the IETF Trust and authors Copyright Line does not match the current year -- The document date (January 24, 2017) is 2648 days in the past. Is this intentional? Checking references for intended status: Proposed Standard ---------------------------------------------------------------------------- (See RFCs 3967 and 4897 for information about using normative references to lower-maturity documents in RFCs) No issues found here. Summary: 0 errors (**), 0 flaws (~~), 1 warning (==), 1 comment (--). Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 2 PCE Working Group D. Dhody 3 Internet-Draft U. Palle 4 Intended status: Standards Track Huawei Technologies 5 Expires: July 24, 2017 R. Singh 6 Juniper Networks 7 R. Gandhi 8 Individual Contributor 9 L. Fang 10 eBay 11 January 24, 2017 13 PCEP Extensions for MPLS-TE LSP Automatic Bandwidth Adjustment with 14 Stateful PCE 15 draft-ietf-pce-stateful-pce-auto-bandwidth-00 17 Abstract 19 The Path Computation Element Communication Protocol (PCEP) provides 20 mechanisms for Path Computation Elements (PCEs) to perform path 21 computations in response to Path Computation Clients (PCCs) requests. 22 The stateful PCE extensions allow stateful control of Multi-Protocol 23 Label Switching (MPLS) Traffic Engineering Label Switched Paths (TE 24 LSPs) using PCEP. 26 This document describes PCEP extensions for automatic bandwidth 27 adjustment when employing an Active Stateful PCE for both PCE- 28 initiated and PCC-initiated LSPs. 30 Status of This Memo 32 This Internet-Draft is submitted in full conformance with the 33 provisions of BCP 78 and BCP 79. 35 Internet-Drafts are working documents of the Internet Engineering 36 Task Force (IETF). Note that other groups may also distribute 37 working documents as Internet-Drafts. The list of current Internet- 38 Drafts is at http://datatracker.ietf.org/drafts/current/. 40 Internet-Drafts are draft documents valid for a maximum of six months 41 and may be updated, replaced, or obsoleted by other documents at any 42 time. It is inappropriate to use Internet-Drafts as reference 43 material or to cite them other than as "work in progress." 45 Copyright Notice 47 Copyright (c) 2017 IETF Trust and the persons identified as the 48 document authors. All rights reserved. 50 This document is subject to BCP 78 and the IETF Trust's Legal 51 Provisions Relating to IETF Documents 52 (http://trustee.ietf.org/license-info) in effect on the date of 53 publication of this document. Please review these documents 54 carefully, as they describe your rights and restrictions with respect 55 to this document. Code Components extracted from this document must 56 include Simplified BSD License text as described in Section 4.e of 57 the Trust Legal Provisions and are provided without warranty as 58 described in the Simplified BSD License. 60 Table of Contents 62 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 63 2. Conventions Used in This Document . . . . . . . . . . . . . . 4 64 2.1. Requirements Language . . . . . . . . . . . . . . . . . . 4 65 2.2. Terminology . . . . . . . . . . . . . . . . . . . . . . . 4 66 3. Requirements for PCEP Extensions . . . . . . . . . . . . . . . 5 67 4. Architectural Overview . . . . . . . . . . . . . . . . . . . . 6 68 4.1. Auto-Bandwidth Overview . . . . . . . . . . . . . . . . . 6 69 4.2. Auto-bandwidth Theory of Operation . . . . . . . . . . . . 8 70 4.3. Scaling Considerations . . . . . . . . . . . . . . . . . . 8 71 5. Extensions to the PCEP . . . . . . . . . . . . . . . . . . . . 9 72 5.1. Capability Advertisement . . . . . . . . . . . . . . . . . 9 73 5.1.1 AUTO-BANDWIDTH-CAPABILITY TLV . . . . . . . . . . . . . 9 74 5.2. AUTO-BANDWIDTH-ATTRIBUTE TLV . . . . . . . . . . . . . . . 10 75 5.2.1. Sample-Interval sub-TLV . . . . . . . . . . . . . . . 11 76 5.2.2. Adjustment-Interval sub-TLV . . . . . . . . . . . . . 12 77 5.2.3. Adjustment Threshold . . . . . . . . . . . . . . . . . 12 78 5.2.3.1. Adjustment-Threshold sub-TLV . . . . . . . . . . . 12 79 5.2.3.2. Adjustment-Threshold-Percentage sub-TLV . . . . . 13 80 5.2.4. Minimum and Maximum Bandwidth Values . . . . . . . . . 13 81 5.2.4.1. Minimum-Bandwidth sub-TLV . . . . . . . . . . . . 13 82 5.2.4.2. Maximum-Bandwidth sub-TLV . . . . . . . . . . . . 14 83 5.2.5. Overflow and Underflow Conditions . . . . . . . . . . 14 84 5.2.5.1. Overflow-Threshold sub-TLV . . . . . . . . . . . . 14 85 5.2.5.2. Overflow-Threshold-Percentage sub-TLV . . . . . . 15 86 5.2.5.3. Underflow-Threshold sub-TLV . . . . . . . . . . . 16 87 5.2.5.4. Underflow-Threshold-Percentage sub-TLV . . . . . . 17 88 5.3. BANDWIDTH Object . . . . . . . . . . . . . . . . . . . . . 17 89 5.4. The PCInitiate Message . . . . . . . . . . . . . . . . . . 18 90 5.5. The PCRpt Message . . . . . . . . . . . . . . . . . . . . 18 91 5.6. The PCNtf Message . . . . . . . . . . . . . . . . . . . . 18 92 6. Security Considerations . . . . . . . . . . . . . . . . . . . 19 93 7. Manageability Considerations . . . . . . . . . . . . . . . . . 19 94 7.1. Control of Function and Policy . . . . . . . . . . . . . . 19 95 7.2. Information and Data Models . . . . . . . . . . . . . . . 19 96 7.3. Liveness Detection and Monitoring . . . . . . . . . . . . 19 97 7.4. Verify Correct Operations . . . . . . . . . . . . . . . . 20 98 7.5. Requirements On Other Protocols . . . . . . . . . . . . . 20 99 7.6. Impact On Network Operations . . . . . . . . . . . . . . . 20 100 8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 21 101 8.1. PCEP TLV Type Indicators . . . . . . . . . . . . . . . . . 21 102 8.2. AUTO-BANDWIDTH-CAPABILITY TLV Flag Field . . . . . . . . . 21 103 8.3. AUTO-BANDWIDTH-ATTRIBUTE Sub-TLV . . . . . . . . . . . . . 21 104 8.4. Error Object . . . . . . . . . . . . . . . . . . . . . . . 22 105 8.5. Notification Object . . . . . . . . . . . . . . . . . . . 22 106 9. References . . . . . . . . . . . . . . . . . . . . . . . . . . 22 107 9.1. Normative References . . . . . . . . . . . . . . . . . . . 22 108 9.2. Informative References . . . . . . . . . . . . . . . . . . 23 109 Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . 24 110 Contributors' Addresses . . . . . . . . . . . . . . . . . . . . . 24 111 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 25 113 1. Introduction 115 [RFC5440] describes the Path Computation Element Protocol (PCEP) as a 116 communication mechanism between a Path Computation Client (PCC) and a 117 Path Control Element (PCE), or between PCE and PCE, that enables 118 computation of Multi-Protocol Label Switching (MPLS) Traffic 119 Engineering Label Switched Paths (TE LSPs). 121 [I-D.ietf-pce-stateful-pce] specifies extensions to PCEP to enable 122 stateful control of MPLS TE LSPs. It describes two mode of 123 operations - Passive stateful PCE and Active stateful PCE. In this 124 document, the focus is on Active stateful PCE where LSPs are 125 configured at the PCC and control over them is delegated to the PCE. 126 Further [I-D.ietf-pce-pce-initiated-lsp] describes the setup, 127 maintenance and teardown of PCE-initiated LSPs for the stateful PCE 128 model. 130 Over time, based on the varying traffic pattern, an LSP established 131 with certain bandwidth may require to adjust the bandwidth, reserved 132 in the network automatically. Ingress Label Switch Router (LSR) 133 collects the traffic rate at each sample interval to determine the 134 bandwidth demand of the LSP. This bandwidth information is then used 135 to adjust the LSP bandwidth periodically. This feature is commonly 136 referred to as Auto-Bandwidth. 138 Enabling Auto-Bandwidth feature on an LSP results in the LSP 139 automatically adjusting its bandwidth reservation based on the actual 140 traffic flowing through the LSP. The initial LSP bandwidth can be 141 set to an arbitrary value (including zero), in practice, it can be 142 operator expected value based on design and planning. Once the LSP 143 is set-up, the LSP monitors the traffic flow and adjusts its 144 bandwidth every adjustment-interval period. The bandwidth adjustment 145 uses the make-before-break signaling method so that there is no 146 interruption to the traffic flow. The Auto-Bandwidth is described in 147 detail in Section 4.1. [I-D.ietf-pce-stateful-pce-app] describes the 148 use-case for Auto-Bandwidth adjustment for passive and active 149 stateful PCE. 151 o The PCC (head-end of the LSP) monitors and calculates the new 152 adjusted bandwidth. The PCC reports the calculated bandwidth to 153 be adjusted to the PCE. 155 o This approach would be similar to passive stateful PCE model, 156 while the passive stateful PCE uses path request/reply mechanism, 157 the active stateful PCE uses report/update mechanism to adjust the 158 LSP bandwidth. 160 o For PCE-initiated LSP, the PCC is requested during the LSP 161 initiation to monitor and calculate the new adjusted bandwidth. 163 This document defines extensions needed to support Auto-Bandwidth 164 feature on the LSPs in a active stateful PCE model using PCEP. 166 2. Conventions Used in This Document 168 2.1. Requirements Language 170 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 171 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this 172 document are to be interpreted as described in [RFC2119]. 174 2.2. Terminology 176 The following terminology is used in this document. 178 Active Stateful PCE: PCE that uses tunnel state information learned 179 from PCCs to optimize path computations. Additionally, it 180 actively updates tunnel parameters in those PCCs that delegated 181 control over their tunnels to the PCE. 183 Delegation: An operation to grant a PCE temporary rights to modify a 184 subset of tunnel parameters on one or more PCC's tunnels. Tunnels 185 are delegated from a PCC to a PCE. 187 PCC: Path Computation Client. Any client application requesting a 188 path computation to be performed by a Path Computation Element. 190 PCE: Path Computation Element. An entity (component, application, 191 or network node) that is capable of computing a network path or 192 route based on a network graph and applying computational 193 constraints. 195 TE LSP: Traffic Engineering Label Switched Path. 197 Note the Auto-Bandwidth feature specific terms defined in Section 198 4.1. 200 3. Requirements for PCEP Extensions 202 The PCEP speaker supporting this document MUST have a mechanism to 203 advertise the automatic bandwidth adjustment capability. 205 PCEP extensions required are summarized in the following table. 207 +---------------------------------+---------------------------------+ 208 | PCC Initiated | PCE Initiated | 209 +---------------------------------+---------------------------------+ 210 | | | 211 | PCC monitors the traffic | At the time of initiation, | 212 | and reports the calculated | PCE request PCC to monitor | 213 | bandwidth to be adjusted | the traffic and report the | 214 | to the PCE. | calculated bandwidth to be | 215 | | adjusted to the PCE. | 216 | | | 217 | No new extensions are needed. | Extension is needed for PCE | 218 | | to pass on the adjustment | 219 | | parameters at the time of | 220 | | Initiation. | 221 | | | 222 +---------------------------------+---------------------------------+ 224 Table 1: Auto-Bandwidth PCEP extensions 226 Further Auto-Bandwidth deployment considerations are summarized 227 below: 229 o It is required to identify and inform the PCEP peer, the LSP that 230 are enabled with Auto-Bandwidth feature. Not all LSPs in some 231 deployments would like their bandwidth to be dependent on the 232 real-time bandwidth usage but be constant as set by the operator. 234 o Further for the LSP with Auto-Bandwidth feature enabled, an 235 operator should be able to specify the adjustment parameters (i.e. 236 configuration knobs) to control this feature (e.g. minimum/ 237 maximum bandwidth range) and PCEP peer should be informed. 239 4. Architectural Overview 241 4.1. Auto-Bandwidth Overview 243 Auto-Bandwidth feature allows an LSP to automatically and dynamically 244 adjust its reserved bandwidth over time, i.e. without network 245 operator intervention. The bandwidth adjustment uses the 246 make-before-break signaling method so that there is no interruption 247 to the traffic flow. 249 The new bandwidth reservation is determined by sampling the actual 250 traffic flowing through the LSP. If the traffic flowing through the 251 LSP is lower than the configured or current bandwidth of the LSP, the 252 extra bandwidth is being reserved needlessly and being wasted. 253 Conversely, if the actual traffic flowing through the LSP is higher 254 than the configured or current bandwidth of the LSP, it can 255 potentially cause congestion or packet loss in the network. With 256 Auto-Bandwidth feature, the LSP bandwidth can be set to some 257 arbitrary value (including zero) during initial setup time, and it 258 will be periodically adjusted over time based on the actual bandwidth 259 requirement. 261 Note the following definitions of the Auto-Bandwidth terms: 263 Maximum Average Bandwidth (MaxAvgBw): The maximum average bandwidth 264 represents the current traffic bandwidth demand during a time 265 interval. This is the maximum value of the averaged traffic 266 bandwidth rate in a given adjustment-interval. 268 Adjusted Bandwidth: This is the Auto-Bandwidth computed bandwidth 269 that needs to be adjusted for the LSP. 271 Sample-Interval: The periodic time interval at which the traffic 272 rate is collected as a sample. 274 Bandwidth-Sample (BwSample): The bandwidth sample collected at every 275 sample interval to measure the traffic rate. 277 Adjustment-Interval: The periodic time interval at which the 278 bandwidth adjustment should be made using the MaxAvgBw. 280 Maximum-Bandwidth: The maximum bandwidth that can be reserved for 281 the LSP. 283 Minimum-Bandwidth: The minimum bandwidth that can be reserved for 284 the LSP. 286 Adjustment-Threshold: This value is used to decide when the 287 bandwidth should be adjusted. If the percentage or absolute 288 difference between the current MaxAvgBw and the current bandwidth 289 reservation is greater than or equal to the threshold value, the 290 LSP bandwidth is adjusted to the current bandwidth demand 291 (Adjusted Bandwidth) at the adjustment-interval expiry. 293 Overflow-Count: This value is used to decide when the bandwidth 294 should be adjusted when there is a sudden increase in traffic 295 demand. This value indicates how many times consecutively, the 296 percentage or absolute difference between the current MaxAvgBw and 297 the current bandwidth reservation is greater than or equal to the 298 Overflow-Threshold value. 300 Overflow-Threshold: This value is used to decide when the bandwidth 301 should be adjusted when there is a sudden increase in traffic 302 demand. If the percentage or absolute difference between the 303 current MaxAvgBw and the current bandwidth reservation is greater 304 than or equal to the threshold value, the overflow-condition is 305 set to be met. The LSP bandwidth is adjusted to the current 306 bandwidth demand bypassing the adjustment-interval if the 307 overflow-condition is met consecutively for the Overflow-Count. 309 Underflow-Count: This value is used to decide when the bandwidth 310 should be adjusted when there is a sudden decrease in traffic 311 demand. This value indicates how many times consecutively, the 312 percentage or absolute difference between the current MaxAvgBw and 313 the current bandwidth reservation is greater than or equal to the 314 Underflow-Threshold value. 316 Underflow-Threshold: This value is used to decide when the bandwidth 317 should be adjusted when there is a sudden decrease in traffic 318 demand. If the percentage or absolute difference between the 319 current MaxAvgBw and the current bandwidth reservation is greater 320 than or equal to the threshold value, the underflow-condition is 321 set to be met. The LSP bandwidth is adjusted to the current 322 bandwidth demand bypassing the adjustment-interval if the 323 underflow-condition is met consecutively for the Underflow-Count. 325 4.2. Auto-bandwidth Theory of Operation 327 The traffic rate is periodically sampled at each sample-interval 328 (which can be configured by the user and the default value as 5 329 minutes) by the head-end node of the LSP. The sampled traffic rates 330 are accumulated over the adjustment-interval period (which can be 331 configured by the user and the default value as 24 hours). The PCEP 332 peer which is in-charge of calculating the bandwidth to be adjusted, 333 will adjust the bandwidth of the LSP to the highest sampled traffic 334 rate (MaxAvgBw) amongst the set of bandwidth samples collected over 335 the adjustment-interval. 337 Note that the highest sampled traffic rate could be higher or lower 338 than the current LSP bandwidth. Only if the difference between the 339 current bandwidth demand (MaxAvgBw) and the current bandwidth 340 reservation is greater than or equal to the Adjustment-Threshold 341 (percentage or absolute value), the LSP bandwidth is adjusted to the 342 current bandwidth demand (MaxAvgBw). Some LSPs are less eventful 343 while other LSPs may encounter a lot of changes in the traffic 344 pattern. PCE sets the intervals for adjustment based on the traffic 345 pattern of the LSP. 347 In order to avoid frequent re-signaling, an operator may set a longer 348 adjustment-interval value. However, longer adjustment-interval can 349 result in an undesirable effect of masking sudden changes in traffic 350 demands of an LSP. To avoid this, the Auto-Bandwidth feature may 351 pre-maturely expire the adjustment-interval and adjust the LSP 352 bandwidth to accommodate the sudden bursts of increase in traffic 353 demand as an overflow condition or decrease in traffic demand as an 354 underflow condition. 356 All thresholds in this document could be represented in both absolute 357 value and percentage, and could be used together. 359 4.3. Scaling Considerations 361 It should be noted that any bandwidth change would require re- 362 signaling of an LSP in a make-before-break fashion, which can further 363 trigger preemption of lower priority LSPs in the network. When 364 deployed under scale, this can lead to a signaling churn in the 365 network. The Auto-bandwidth application algorithm is thus advised to 366 take this into consideration before adjusting the LSP bandwidth. 367 Operators are advised to set the values of various auto-bandwidth 368 adjustment parameters appropriate for the deployed LSP scale. 370 If a PCE gets overwhelmed, it can notify the PCC to temporarily 371 suspend its auto-bandwidth reporting (see Section 5.6). Similarly if 372 a PCC gets overwhelmed due to signaling churn, it can notify the PCE 373 to temporarily suspend the LSP bandwidth adjustment. 375 5. Extensions to the PCEP 377 5.1. Capability Advertisement 379 During PCEP Initialization Phase, PCEP Speakers (PCE or PCC) 380 advertise their support of Automatic Bandwidth Adjustment. A PCEP 381 Speaker includes the "Auto-Bandwidth Capability" TLV, in the OPEN 382 Object to advertise its support for PCEP Auto-Bandwidth extensions. 383 The presence of the "Auto-Bandwidth Capability" TLV in the OPEN 384 Object indicates that the Automatic Bandwidth Adjustment is supported 385 as described in this document. 387 The PCEP protocol extensions for Auto-Bandwidth adjustments MUST NOT 388 be used if one or both PCEP Speakers have not included the "Auto- 389 Bandwidth Capability" TLV in their respective OPEN message. If the 390 PCEP speaker that supports the extensions of this draft but did not 391 advertise this capability, then upon receipt of AUTO-BANDWIDTH- 392 ATTRIBUTE TLV in LSPA object, it SHOULD generate a PCErr with error- 393 type 19 (Invalid Operation), error-value TBD4 (Auto-Bandwidth 394 capability was not advertised) and it will terminate the PCEP 395 session. 397 5.1.1 AUTO-BANDWIDTH-CAPABILITY TLV 399 The AUTO-BANDWIDTH-CAPABILITY TLV is an optional TLV for use in the 400 OPEN Object for Automatic Bandwidth Adjustment via PCEP capability 401 advertisement. Its format is shown in the following figure: 403 0 1 2 3 404 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 1 405 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 406 | Type=[TBD5] | Length=4 | 407 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 408 | Flags | 409 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 411 AUTO-BANDWIDTH-CAPABILITY TLV format 413 The type of the TLV is (TBD5) and it has a fixed length of 4 octets. 415 The value comprises a single field - Flags (32 bits). Currently no 416 flags are defined for this TLV. 418 Unassigned bits are considered reserved. They MUST be set to 0 on 419 transmission and MUST be ignored on receipt. 421 Advertisement of the Auto-Bandwidth capability TLV implies support of 422 auto-bandwidth adjustment, as well as the objects, TLVs and 423 procedures defined in this document. 425 5.2. AUTO-BANDWIDTH-ATTRIBUTE TLV 427 The AUTO-BANDWIDTH-ATTRIBUTE TLV provides the 'configurable knobs' of 428 the feature and it can be included as an optional TLV in the LSPA 429 Object (as described in [RFC5440]). 431 For PCE-Initiated LSP ([I-D.ietf-pce-pce-initiated-lsp]), this TLV is 432 included in the LSPA Object with PCInitiate message. For delegated 433 LSPs, this TLV is carried in PCRpt message in LSPA Object. 435 The TLV is encoded in all PCEP messages for the LSP till the auto 436 bandwidth adjustment feature is enabled, the absence of the TLV 437 indicate the PCEP speaker wish to disable the feature. 439 The format of the AUTO-BANDWIDTH-ATTRIBUTE TLV is shown in the 440 following figure: 442 0 1 2 3 443 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 1 444 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 445 | Type=[TBD1] | Length | 446 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 447 | | 448 // sub-TLVs // 449 | | 450 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 452 AUTO-BANDWIDTH-ATTRIBUTE TLV format 454 Type: TBD1 456 Length: Variable 458 Value: This comprises one or more sub-TLVs. 460 Following sub-TLVs are defined in this document: 462 Type Len Name 463 ------------------------------------------------------------------- 464 1 4 Sample-Interval sub-TLV 465 2 4 Adjustment-Interval sub-TLV 466 3 4 Adjustment-Threshold sub-TLV 467 4 4 Adjustment-Threshold-Percentage sub-TLV 468 5 4 Minimum-Bandwidth sub-TLV 469 6 4 Maximum-Bandwidth sub-TLV 470 7 8 Overflow-Threshold sub-TLV 471 8 4 Overflow-Threshold-Percentage sub-TLV 472 9 8 Underflow-Threshold sub-TLV 473 10 4 Underflow-Threshold-Percentage sub-TLV 475 Future specification can define additional sub-TLVs. 477 The presence of AUTO-BANDWIDTH-ATTRIBUTE TLV in LSPA Object means 478 that the automatic bandwidth adjustment feature is enabled. All 479 sub-TLVs are optional and any unrecognized sub-TLV MUST be silently 480 ignored. If a sub-TLV of same type appears more than once, only the 481 first occurrence is processed and all others MUST be ignored. 483 The AUTO-BANDWIDTH-ATTRIBUTE TLV can also be carried in PCUpd message 484 in LSPA Object in order to make updates to auto-bandwidth attributes 485 such as Adjustment-Interval. 487 If sub-TLVs are not present, the default values based on the local 488 policy are assumed. 490 The sub-TLVs are encoded to inform the PCEP peer the various sampling 491 and adjustment parameters. 493 The following sub-sections describe the sub-TLVs which are currently 494 defined to be carried within the AUTO-BANDWIDTH-ATTRIBUTE TLV. 496 5.2.1. Sample-Interval sub-TLV 498 The Sample-Interval sub-TLV specifies a time interval in seconds at 499 which traffic samples are collected at the PCC. 501 The Type is 1, Length is 4, and the value comprises of 4-octet time 502 interval, the valid range is from 1 to 604800, in seconds. The 503 default value is 300 seconds. 505 0 1 2 3 506 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 1 507 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 508 | Type=1 | Length=4 | 509 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 510 | Sample-Interval | 511 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 512 Sample-Interval sub-TLV format 514 5.2.2. Adjustment-Interval sub-TLV 516 The Adjustment-Interval sub-TLV specifies a time interval in seconds 517 at which bandwidth adjustment should be made. 519 The Type is 2, Length is 4, and the value comprises of 4-octet time 520 interval, the valid range is from 1 to 604800, in seconds. The 521 default value is 300 seconds. 523 0 1 2 3 524 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 1 525 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 526 | Type=2 | Length=4 | 527 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 528 | Adjustment-Interval | 529 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 531 Adjustment-Interval sub-TLV format 533 5.2.3. Adjustment Threshold 535 The sub-TLVs in this section are encoded to inform the PCEP peer the 536 adjustment threshold parameters. An implementation MAY include both 537 sub-TLVs for the absolute value and the percentage, in which case the 538 bandwidth is adjusted when either of the adjustment threshold 539 conditions are met. 541 5.2.3.1. Adjustment-Threshold sub-TLV 543 The Adjustment-Threshold sub-TLV is used to decide when the LSP 544 bandwidth should be adjusted. 546 0 1 2 3 547 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 1 548 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 549 | Type=3 | Length=4 | 550 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 551 | Adjustment Threshold | 552 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 554 Adjustment-Threshold sub-TLV format 556 The Type is 3, Length is 4, and the value comprises of - 558 o Adjustment Threshold: The absolute Adjustment-Threshold bandwidth 559 value, encoded in IEEE floating point format (see 561 [IEEE.754.1985]), expressed in bytes per second. Refer to Section 562 3.1.2 of [RFC3471] for a table of commonly used values. 564 If the difference between the current MaxAvgBw and the current 565 bandwidth reservation is greater than or equal to the threshold 566 value, the LSP bandwidth is adjusted to the current bandwidth 567 demand. 569 5.2.3.2. Adjustment-Threshold-Percentage sub-TLV 571 The Adjustment-Threshold-Percentage sub-TLV is used to decide when 572 the LSP bandwidth should be adjusted. 574 0 1 2 3 575 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 1 576 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 577 | Type=4 | Length=4 | 578 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 579 | Reserved | Percentage | 580 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 582 Adjustment-Threshold-Percentage sub-TLV format 584 The Type is 4, Length is 4, and the value comprises of - 586 o Reserved: SHOULD be set to zero on transmission and MUST be 587 ignored on receipt. 589 o Percentage: The Adjustment-Threshold value, encoded in percentage 590 (an integer from 0 to 100). If the percentage difference between 591 the current MaxAvgBw and the current bandwidth reservation is 592 greater than or equal to the threshold percentage, the LSP 593 bandwidth is adjusted to the current bandwidth demand. 595 5.2.4. Minimum and Maximum Bandwidth Values 597 5.2.4.1. Minimum-Bandwidth sub-TLV 599 The Minimum-Bandwidth sub-TLV specify the minimum bandwidth allowed 600 for the LSP, and is expressed in bytes per second. The LSP bandwidth 601 cannot be adjusted below the minimum bandwidth value. 603 The Type is 5, Length is 4, and the value comprises of 4-octet 604 bandwidth value encoded in IEEE floating point format (see 605 [IEEE.754.1985]), expressed in bytes per second. Refer to Section 606 3.1.2 of [RFC3471] for a table of commonly used values. 608 0 1 2 3 609 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 1 610 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 611 | Type=5 | Length=4 | 612 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 613 | Minimum-Bandwidth | 614 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 616 Minimum-Bandwidth sub-TLV format 618 5.2.4.2. Maximum-Bandwidth sub-TLV 620 The Maximum-Bandwidth sub-TLV specify the maximum bandwidth allowed 621 for the LSP, and is expressed in bytes per second. The LSP bandwidth 622 cannot be adjusted above the maximum bandwidth value. 624 The Type is 6, Length is 4, and the value comprises of 4-octet 625 bandwidth value encoded in IEEE floating point format (see 626 [IEEE.754.1985]), expressed in bytes per second. Refer to Section 627 3.1.2 of [RFC3471] for a table of commonly used values. 629 0 1 2 3 630 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 1 631 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 632 | Type=6 | Length=4 | 633 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 634 | Maximum-Bandwidth | 635 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 637 Maximum-Bandwidth sub-TLV format 639 5.2.5. Overflow and Underflow Conditions 641 The sub-TLVs in this section are encoded to inform the PCEP peer the 642 overflow and underflow threshold parameters. An implementation MAY 643 include sub-TLVs for the absolute value and the percentage for the 644 threshold, in which case the bandwidth is immediately adjusted when 645 either of the adjustment threshold conditions are met consecutively 646 for the given count. 648 5.2.5.1. Overflow-Threshold sub-TLV 650 The Overflow-Threshold sub-TLV is used to decide if the bandwidth 651 should be adjusted immediately. 653 0 1 2 3 654 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 1 655 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 656 | Type=7 | Length=8 | 657 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 658 | Reserved | Count | 659 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 660 | Overflow Threshold | 661 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 663 Overflow-Threshold sub-TLV format 665 The Type is 7, Length is 8, and the value comprises of - 667 o Reserved: SHOULD be set to zero on transmission and MUST be 668 ignored on receipt. 670 o Count: The Overflow-Count value, encoded in integer. The value 0 671 is considered to be invalid. The number of consecutive samples 672 for which the overflow condition MUST be met for the LSP bandwidth 673 to be immediately adjusted to the current bandwidth demand, 674 bypassing the adjustment-interval. 676 o Overflow Threshold: The absolute Overflow-Threshold bandwidth 677 value, encoded in IEEE floating point format (see 678 [IEEE.754.1985]), expressed in bytes per second. Refer to Section 679 3.1.2 of [RFC3471] for a table of commonly used values. If the 680 increase of the current MaxAvgBw from the current bandwidth 681 reservation is greater than or equal to the threshold value, the 682 overflow condition is met. 684 5.2.5.2. Overflow-Threshold-Percentage sub-TLV 686 The Overflow-Threshold-Percentage sub-TLV is used to decide if the 687 bandwidth should be adjusted immediately. 689 0 1 2 3 690 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 1 691 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 692 | Type=8 | Length=4 | 693 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 694 | Percentage | Reserved | Count | 695 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 697 Overflow-Threshold-Percentage sub-TLV format 699 The Type is 8, Length is 4, and the value comprises of - 700 o Percentage: The Overflow-Threshold value, encoded in percentage 701 (an integer from 0 to 100). If the percentage increase of the 702 current MaxAvgBw from the current bandwidth reservation is greater 703 than or equal to the threshold percentage, the overflow condition 704 is met. 706 o Reserved: SHOULD be set to zero on transmission and MUST be 707 ignored on receipt. 709 o Count: The Overflow-Count value, encoded in integer. The value 0 710 is considered to be invalid. The number of consecutive samples 711 for which the overflow condition MUST be met for the LSP bandwidth 712 to be immediately adjusted to the current bandwidth demand, 713 bypassing the adjustment-interval. 715 5.2.5.3. Underflow-Threshold sub-TLV 717 The Underflow-Threshold sub-TLV is used to decide if the bandwidth 718 should be adjusted immediately. 720 0 1 2 3 721 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 1 722 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 723 | Type=9 | Length=8 | 724 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 725 | Reserved | Count | 726 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 727 | Underflow Threshold | 728 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 730 Underflow-Threshold sub-TLV format 732 The Type is 9, Length is 8, and the value comprises of - 734 o Reserved: SHOULD be set to zero on transmission and MUST be 735 ignored on receipt. 737 o Count: The Underflow-Count value, encoded in integer. The value 0 738 is considered to be invalid. The number of consecutive samples 739 for which the underflow condition MUST be met for the LSP 740 bandwidth to be immediately adjusted to the current bandwidth 741 demand, bypassing the adjustment-interval. 743 o Underflow Threshold: The absolute Underflow-Threshold bandwidth 744 value, encoded in IEEE floating point format (see 745 [IEEE.754.1985]), expressed in bytes per second. Refer to Section 746 3.1.2 of [RFC3471] for a table of commonly used values. If the 747 decrease of the current MaxAvgBw from the current bandwidth 748 reservation is greater than or equal to the threshold value, the 749 underflow condition is met. 751 5.2.5.4. Underflow-Threshold-Percentage sub-TLV 753 The Underflow-Threshold-Percentage sub-TLV is used to decide if the 754 bandwidth should be adjusted immediately. 756 0 1 2 3 757 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 1 758 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 759 | Type=10 | Length=4 | 760 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 761 | Percentage | Reserved | Count | 762 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 764 Underflow-Threshold-Percentage sub-TLV format 766 The Type is 10, Length is 4, and the value comprises of - 768 o Percentage: The Underflow-Threshold value, encoded in percentage 769 (an integer from 0 to 100). If the percentage decrease of the 770 current MaxAvgBw from the current bandwidth reservation is greater 771 than or equal to the threshold percentage, the underflow condition 772 is met. 774 o Reserved: SHOULD be set to zero on transmission and MUST be 775 ignored on receipt. 777 o Count: The Underflow-Count value, encoded in integer. The value 0 778 is considered to be invalid. The number of consecutive samples 779 for which the underflow condition MUST be met for the LSP 780 bandwidth to be immediately adjusted to the current bandwidth 781 demand, bypassing the adjustment-interval. 783 5.3. BANDWIDTH Object 785 As per [RFC5440], the BANDWIDTH object (Object-Class value 5) is 786 defined with two Object-Type values as following: 788 o Requested Bandwidth: BANDWIDTH Object-Type value is 1. 790 o Re-optimization Bandwidth: Bandwidth of an existing TE LSP for 791 which a re-optimization is requested. BANDWIDTH Object-Type value 792 is 2. 794 PCC reports the calculated bandwidth to be adjusted (MaxAvgBw) to the 795 PCE using existing 'Requested Bandwidth with BANDWIDTH Object-Type as 796 1. 798 5.4. The PCInitiate Message 800 A PCInitiate message is a PCEP message sent by a PCE to a PCC to 801 trigger LSP instantiation or deletion [I.D.ietf-pce-pce-initiated- 802 lsp]. 804 For the PCE-initiated LSP [I-D.ietf-pce-pce-initiated-lsp] with 805 Auto-Bandwidth feature enabled, AUTO-BANDWIDTH-ATTRIBUTE TLV MUST be 806 included in the LSPA object with the PCInitiate message. The rest of 807 the processing remains unchanged. 809 5.5. The PCRpt Message 811 As specified in [I.D.ietf-pce-pce-initiated-lsp], the PCC creates the 812 LSP using the attributes communicated by the PCE, and local values 813 for the unspecified parameters. After the successful instantiation 814 of the LSP, PCC automatically delegates the LSP to the PCE and 815 generates an LSP State Report (PCRpt) for the LSP. 817 When LSP is delegated to a PCE for the very first time, BANDWIDTH 818 object of type 1 is used to specify the requested bandwidth in the 819 PCRpt message. 821 When the LSP is enabled with the Auto-Bandwidth feature, PCC SHOULD 822 include the BANDWIDTH object of type 1 to specify the calculated 823 bandwidth to be adjusted to the PCE in the PCRpt message. 825 The definition of the PCRpt message (see [I-D.ietf-pce-stateful-pce]) 826 is unchanged by this document. 828 5.6. The PCNtf Message 830 As per [RFC5440], the PCEP Notification message (PCNtf) can be sent 831 by a PCEP speaker to notify its peer of a specific event. As 832 described in Section 4.3 of this document, a PCEP speaker SHOULD 833 notify its PCEP peer that it is overwhelmed, and on receipt of such 834 notification the peer SHOULD NOT send any PCEP messages related to 835 auto-bandwidth adjustment. If a PCEP message related to auto- 836 bandwidth adjustment is received, it MUST be silently ignored. 838 When a PCEP speaker is overwhelmed, it SHOULD notify its peer by 839 sending a PCNtf message with Notification Type = TBD6 (Auto-bandwidth 840 Overwhelm State) and Notification Value = 1 (Entering auto-bandwidth 841 overwhelm state). Optionally, OVERLOADED-DURATION TLV [RFC5440] MAY 842 be included that specifies the time period during which no further 843 PCEP messages related to auto-bandwidth adjustment should be sent. 844 When the PCEP speaker is no longer in the overwhelm state and is 845 available to process the auto-bandwidth adjustment, it SHOULD notify 846 its peer by sending a PCNtf message with Notification Type = TBD6 847 (Auto-bandwidth Overwhelm State) and Notification Value = 2 (Clearing 848 auto-bandwidth overwhelm state). 850 When Auto-Bandwidth feature is deployed, a PCE can send this 851 notification to PCC when a PCC is reporting frequent auto-bandwidth 852 adjustments. If a PCC is overwhelmed with re-signaling/re-routing, 853 it can also notify the PCE to not adjust the LSP bandwidth while in 854 overwhelm state. 856 6. Security Considerations 858 This document defines AUTO-BANDWIDTH-CAPABILITY TLV, 859 AUTO-BANDWIDTH-ATTRIBUTE TLV which do not add any new security 860 concerns beyond those discussed in [RFC5440] and 861 [I-D.ietf-pce-stateful-pce]. 863 Some deployments may find the reporting of the auto-bandwidth 864 information as extra sensitive and thus SHOULD employ suitable PCEP 865 security mechanisms like TCP-AO or [I-D.ietf-pce-pceps]. 867 7. Manageability Considerations 869 7.1. Control of Function and Policy 871 The Auto-Bandwidth feature SHOULD be controlled per tunnel (at 872 ingress (PCC) or PCE), the values for parameters like sample- 873 interval, adjustment-interval, minimum-bandwidth, maximum-bandwidth, 874 adjustment-threshold SHOULD be configurable by an operator. 876 7.2. Information and Data Models 878 [RFC7420] describes the PCEP MIB, there are no new MIB Objects 879 defined in this document. 881 7.3. Liveness Detection and Monitoring 883 Mechanisms defined in this document do not imply any new liveness 884 detection and monitoring requirements in addition to those already 885 listed in [RFC5440]. 887 7.4. Verify Correct Operations 889 Mechanisms defined in this document do not imply any new operation 890 verification requirements in addition to those already listed in 891 [RFC5440]. 893 7.5. Requirements On Other Protocols 895 Mechanisms defined in this document do not add any new requirements 896 on other protocols. 898 7.6. Impact On Network Operations 900 Mechanisms defined in this document do not have any impact on network 901 operations in addition to those already listed in [RFC5440]. 903 8. IANA Considerations 905 8.1. PCEP TLV Type Indicators 907 This document defines the following new PCEP TLVs; IANA is requested 908 to make the following allocations from this registry. 909 . 912 Value Name Reference 913 -------------------------------------------------------------- 914 TBD5 AUTO-BANDWIDTH-CAPABILITY [This I.D.] 915 TBD1 AUTO-BANDWIDTH-ATTRIBUTE [This I.D.] 917 8.2. AUTO-BANDWIDTH-CAPABILITY TLV Flag Field 919 IANA is requested to create a registry to manage the Flag field of 920 the AUTO-BANDWIDTH-CAPABILITY TLV. 922 New bit numbers may be allocated only by an IETF Consensus action. 923 Each bit should be tracked with the following qualities: 925 o Bit number (counting from bit 0 as the most significant bit) 927 o Capability description 929 o Defining RFC 931 No bit is defined for the AUTO-BANDWIDTH-CAPABILITY TLV Object flag 932 field in this document. 934 8.3. AUTO-BANDWIDTH-ATTRIBUTE Sub-TLV 936 This document specifies the AUTO-BANDWIDTH-ATTRIBUTE Sub-TLVs. IANA 937 is requested to create an "AUTO-BANDWIDTH-ATTRIBUTE Sub-TLV Types" 938 sub-registry in the "PCEP TLV Type Indicators" for the sub-TLVs 939 carried in the AUTO-BANDWIDTH-ATTRIBUTE TLV. This document defines 940 the following types: 942 Type Name Reference 943 -------------------------------------------------------------- 944 0 Reserved [This I.D.] 945 1 Sample-Interval sub-TLV [This I.D.] 946 2 Adjustment-Interval sub-TLV [This I.D.] 947 3 Adjustment-Threshold sub-TLV [This I.D.] 948 4 Adjustment-Threshold-Percentage sub-TLV [This I.D.] 949 5 Minimum-Bandwidth sub-TLV [This I.D.] 950 6 Maximum-Bandwidth sub-TLV [This I.D.] 951 7 Overflow-Threshold sub-TLV [This I.D.] 952 8 Overflow-Threshold-Percentage sub-TLV [This I.D.] 953 9 Underflow-Threshold sub-TLV [This I.D.] 954 10 Underflow-Threshold-Percentage sub-TLV [This I.D.] 955 11- Unassigned [This I.D.] 956 65535 958 8.4. Error Object 960 This document defines a new Error-Value for PCErr message of type 19 961 (Invalid Operation) [I-D.ietf-pce-stateful-pce]); IANA is requested 962 to make the following allocation from this registry. 963 965 Error-Value Meaning Reference 966 -------------------------------------------------------------- 967 TBD4 Auto-Bandwidth Capability [This I.D.] 968 was not Advertised 970 8.5. Notification Object 972 IANA is requested to allocate new Notification Types and Notification 973 Values within the "Notification Object" sub-registry of the PCEP 974 Numbers registry, as follows: 976 Type Meaning Reference 977 --------------------------------------------------------------- 978 TBD6 Auto-Bandwidth Overwhelm State [This I.D.] 980 Notification-value=1: Entering Auto-Bandwidth 981 overwhelm state 982 Notification-value=2: Clearing Auto-Bandwidth 983 overwhelm state 985 9. References 987 9.1. Normative References 989 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 990 Requirement Levels", BCP 14, RFC 2119, March 1997. 992 [RFC5440] Vasseur, JP. and JL. Le Roux, "Path Computation Element 993 (PCE) Communication Protocol (PCEP)", RFC 5440, March 994 2009. 996 [I-D.ietf-pce-stateful-pce] Crabbe, E., Minei, I., Medved, J., and 997 R. Varga, "PCEP Extensions for Stateful PCE", draft-ietf- 998 pce-stateful-pce (work in progress). 1000 [I-D.ietf-pce-pce-initiated-lsp] Crabbe, E., Minei, I., Sivabalan, 1001 S., and R. Varga, "PCEP Extensions for PCE-initiated LSP 1002 Setup in a Stateful PCE Model", draft-ietf-pce-pce- 1003 initiated-lsp (work in progress). 1005 9.2. Informative References 1007 [RFC3471] Berger, L., "Generalized Multi-Protocol Label Switching 1008 (GMPLS) Signaling Functional Description", RFC 3471, 1009 January 2003. 1011 [RFC7420] Koushik, A., Stephan, E., Zhao, Q., King, D., and J. 1012 Hardwick, "Path Computation Element Communication Protocol 1013 (PCEP) Management Information Base (MIB) Module", RFC 1014 7420, December 2014. 1016 [I-D.ietf-pce-stateful-pce-app] Zhang, X. and I. Minei, 1017 "Applicability of a Stateful Path Computation Element 1018 (PCE)", draft-ietf-pce-stateful-pce-app (work in 1019 progress). 1021 [I-D.ietf-pce-pceps] Lopez, D., Dios, O., Wu, W., and D. Dhody, 1022 "Secure Transport for PCEP", draft-ietf-pce-pceps (work in 1023 progress). 1025 [IEEE.754.1985] Institute of Electrical and Electronics Engineers, 1026 "Standard for Binary Floating-Point Arithmetic", IEEE 1027 Standard 754, August 1985. 1029 Acknowledgments 1031 Authors would like to thank Robert Varga, Venugopal Reddy, Reeja 1032 Paul, Sandeep Boina, Avantika, JP Vasseur and Himanshu Shah for their 1033 useful comments and suggestions. 1035 Contributors' Addresses 1037 He Zekun 1038 Tencent Holdings Ltd, 1039 Shenzhen P.R.China 1041 EMail: kinghe@tencent.com 1043 Xian Zhang 1044 Huawei Technologies 1045 Research Area F3-1B, 1046 Huawei Industrial Base, 1047 Shenzhen, 518129 1048 China 1050 Phone: +86-755-28972645 1051 EMail: zhang.xian@huawei.com 1053 Young Lee 1054 Huawei Technologies 1055 1700 Alma Drive, Suite 100 1056 Plano, TX 75075 1057 USA 1059 Phone: +1 972 509 5599 x2240 1060 Fax: +1 469 229 5397 1061 EMail: leeyoung@huawei.com 1063 Authors' Addresses 1065 Dhruv Dhody 1066 Huawei Technologies 1067 Divyashree Techno Park, Whitefield 1068 Bangalore, Karnataka 560066 1069 India 1071 EMail: dhruv.ietf@gmail.com 1073 Udayasree Palle 1074 Huawei Technologies 1075 Divyashree Techno Park, Whitefield 1076 Bangalore, Karnataka 560037 1077 India 1079 EMail: udayasree.palle@huawei.com 1081 Ravi Singh 1082 Juniper Networks 1083 1194 N. Mathilda Ave. 1084 Sunnyvale, CA 94089 1085 USA 1087 EMail: ravis@juniper.net 1089 Rakesh Gandhi 1090 Individual Contributor 1092 EMail: rgandhi.ietf@gmail.com 1094 Luyuan Fang 1095 eBay 1096 USA 1098 EMail: luyuanf@gmail.com