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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: 'Ta' is mentioned on line 352, but not defined == Missing Reference: 'Tb' is mentioned on line 352, but not defined == Missing Reference: 'TBD1' is mentioned on line 589, but not defined == Missing Reference: 'TBD2' is mentioned on line 707, but not defined ** Downref: Normative reference to an Informational RFC: RFC 8413 == Outdated reference: A later version (-23) exists of draft-ietf-pce-pcep-yang-14 Summary: 1 error (**), 0 flaws (~~), 6 warnings (==), 1 comment (--). Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 2 PCE Working Group H. Chen, Ed. 3 Internet-Draft Futurewei 4 Intended status: Standards Track Y. Zhuang, Ed. 5 Expires: February 8, 2021 Q. Wu 6 Huawei 7 D. Ceccarelli 8 Ericsson 9 August 7, 2020 11 PCEP Extensions for LSP scheduling with stateful PCE 12 draft-ietf-pce-stateful-pce-lsp-scheduling-25 14 Abstract 16 This document defines a set of extensions needed to the stateful Path 17 Computation Element (PCE) communication Protocol (PCEP), so as to 18 enable Labeled Switched Path (LSP) path computation, activation, 19 setup and deletion based on scheduled time intervals for the LSP and 20 the actual network resource usage in a centralized network 21 environment as stated in RFC 8413. 23 Status of This Memo 25 This Internet-Draft is submitted in full conformance with the 26 provisions of BCP 78 and BCP 79. 28 Internet-Drafts are working documents of the Internet Engineering 29 Task Force (IETF). Note that other groups may also distribute 30 working documents as Internet-Drafts. The list of current Internet- 31 Drafts is at https://datatracker.ietf.org/drafts/current/. 33 Internet-Drafts are draft documents valid for a maximum of six months 34 and may be updated, replaced, or obsoleted by other documents at any 35 time. It is inappropriate to use Internet-Drafts as reference 36 material or to cite them other than as "work in progress." 38 This Internet-Draft will expire on February 8, 2021. 40 Copyright Notice 42 Copyright (c) 2020 IETF Trust and the persons identified as the 43 document authors. All rights reserved. 45 This document is subject to BCP 78 and the IETF Trust's Legal 46 Provisions Relating to IETF Documents 47 (https://trustee.ietf.org/license-info) in effect on the date of 48 publication of this document. Please review these documents 49 carefully, as they describe your rights and restrictions with respect 50 to this document. Code Components extracted from this document must 51 include Simplified BSD License text as described in Section 4.e of 52 the Trust Legal Provisions and are provided without warranty as 53 described in the Simplified BSD License. 55 Table of Contents 57 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3 58 2. Conventions used in this document . . . . . . . . . . . . . . 4 59 2.1. Terminology . . . . . . . . . . . . . . . . . . . . . . . 4 60 3. Motivation and Objectives . . . . . . . . . . . . . . . . . . 5 61 4. Procedures and Mechanisms . . . . . . . . . . . . . . . . . . 5 62 4.1. LSP Scheduling Overview . . . . . . . . . . . . . . . . . 5 63 4.2. Support of LSP Scheduling . . . . . . . . . . . . . . . . 7 64 4.2.1. LSP Scheduling . . . . . . . . . . . . . . . . . . . 7 65 4.2.2. Periodical LSP Scheduling . . . . . . . . . . . . . . 7 66 4.3. Scheduled LSP creation . . . . . . . . . . . . . . . . . 9 67 4.4. Scheduled LSP Modifications . . . . . . . . . . . . . . . 10 68 4.5. Scheduled LSP activation and deletion . . . . . . . . . . 11 69 5. PCEP Objects and TLVs . . . . . . . . . . . . . . . . . . . . 11 70 5.1. Stateful PCE Capability TLV . . . . . . . . . . . . . . . 11 71 5.2. LSP Object . . . . . . . . . . . . . . . . . . . . . . . 12 72 5.2.1. SCHED-LSP-ATTRIBUTE TLV . . . . . . . . . . . . . . . 12 73 5.2.2. SCHED-PD-LSP-ATTRIBUTE TLV . . . . . . . . . . . . . 15 74 6. The PCEP Messages . . . . . . . . . . . . . . . . . . . . . . 16 75 6.1. The PCRpt Message . . . . . . . . . . . . . . . . . . . . 16 76 6.2. The PCUpd Message . . . . . . . . . . . . . . . . . . . . 17 77 6.3. The PCInitiate Message . . . . . . . . . . . . . . . . . 17 78 6.4. The PCReq message . . . . . . . . . . . . . . . . . . . . 17 79 6.5. The PCRep Message . . . . . . . . . . . . . . . . . . . . 17 80 6.6. The PCErr Message . . . . . . . . . . . . . . . . . . . . 18 81 7. Implementation Status . . . . . . . . . . . . . . . . . . . . 18 82 8. Security Considerations . . . . . . . . . . . . . . . . . . . 19 83 9. Manageability Consideration . . . . . . . . . . . . . . . . . 19 84 9.1. Control of Function and Policy . . . . . . . . . . . . . 19 85 9.2. Information and Data Models . . . . . . . . . . . . . . . 20 86 9.3. Liveness Detection and Monitoring . . . . . . . . . . . . 20 87 9.4. Verify Correct Operations . . . . . . . . . . . . . . . . 20 88 9.5. Requirements On Other Protocols . . . . . . . . . . . . . 20 89 9.6. Impact On Network Operations . . . . . . . . . . . . . . 20 90 10. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 20 91 10.1. PCEP TLV Type Indicators . . . . . . . . . . . . . . . . 20 92 10.1.1. Opt Field in SCHED-PD-LSP-ATTRIBUTE TLV . . . . . . 21 93 10.1.2. Schedule TLVs Flag Field . . . . . . . . . . . . . . 21 94 10.2. STATEFUL-PCE-CAPABILITY TLV Flag field . . . . . . . . . 21 95 10.3. PCEP-Error Object . . . . . . . . . . . . . . . . . . . 22 96 11. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 22 97 12. References . . . . . . . . . . . . . . . . . . . . . . . . . 22 98 12.1. Normative References . . . . . . . . . . . . . . . . . . 22 99 12.2. Informative References . . . . . . . . . . . . . . . . . 23 100 Appendix A. Contributors Addresses . . . . . . . . . . . . . . . 24 101 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 25 103 1. Introduction 105 The Path Computation Element Protocol (PCEP) defined in [RFC5440] is 106 used between a Path Computation Element (PCE) and a Path Computation 107 Client (PCC) (or other PCE) to enable path computation of Multi- 108 protocol Label Switching (MPLS) Traffic Engineering Label Switched 109 Paths (TE LSPs). 111 [RFC8231] describes a set of extensions to PCEP to provide stateful 112 control. A stateful PCE has access to not only the information 113 carried by the network's Interior Gateway Protocol (IGP) but also the 114 set of active paths and their reserved resources for its 115 computations. The additional state allows the PCE to compute 116 constrained paths while considering individual LSPs and their 117 interactions. 119 Traditionally, the usage and allocation of network resources, 120 especially bandwidth, can be supported by a Network Management System 121 (NMS) operation such as path pre-establishment. However, this does 122 not provide efficient usage of network resources. The established 123 paths reserve the resources forever, which cannot be used by other 124 services even when they are not used for transporting any service. 125 [RFC8413] then provides a framework that describes and discusses the 126 problem, and defines an appropriate architecture for the scheduled 127 reservation of TE resources. 129 The scheduled reservation of TE resources allows network operators to 130 reserve resources in advance according to the agreements with their 131 customers, and allows them to transmit data about scheduling such as 132 a specified start time and duration, for example for a scheduled bulk 133 data replication between data centers. It enables the activation of 134 bandwidth usage at the time the service is really being used while 135 letting other services use it when this service is not using it. The 136 requirement of scheduled LSP provisioning is mentioned in [RFC8231] 137 and [RFC7399]. Also, for deterministic networks 138 [I-D.ietf-detnet-architecture], the scheduled LSP or temporal LSP can 139 provide a better network resource usage for guaranteed links. This 140 idea can also be applied in segment routing [RFC8402] to schedule the 141 network resources over the whole network in a centralized manner as 142 well. 144 With this in mind, this document defines a set of extensions needed 145 to PCEP used for stateful PCEs so as to enable LSP scheduling for 146 path computation and LSP setup/deletion based on the actual network 147 resource usage duration of a traffic service. A scheduled LSP is 148 characterized by a starting time and a duration. When the end of the 149 LSP life is reached, it is deleted to free up the resources for other 150 LSPs (scheduled or not). 152 2. Conventions used in this document 154 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 155 "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and 156 "OPTIONAL" in this document are to be interpreted as described in BCP 157 14 [RFC2119] [RFC8174] when, and only when, they appear in all 158 capitals, as shown here. 160 2.1. Terminology 162 The following terminology is re-used from existing PCE documents. 164 o Active Stateful PCE [RFC8051] 166 o Delegation [RFC8051] 168 o PCE-Initiated LSP [RFC8281] 170 o PCC [RFC5440] 172 o PCE [RFC5440] 174 o TE LSP [RFC5440] 176 o TED [RFC5440] 178 o LSP-DB [RFC8051] 180 In addition, this document defines the following terminologies. 182 Scheduled TE LSP (or Scheduled LSP for short): an LSP with the 183 scheduling attributes, that carries traffic flow demand at a 184 starting time and lasts for a certain duration (or from a starting 185 time to an ending time, where the ending time is the starting time 186 plus the duration). A scheduled LSP is also called a temporal 187 LSP. The PCE operates path computation per LSP availability for 188 the required time and duration. 190 Scheduled LSP-DB: a database of scheduled LSPs. 192 Scheduled TED: Traffic engineering database with the awareness of 193 scheduled resources for TE. This database is generated by the PCE 194 from the information in TED and scheduled LSP-DB and allows 195 knowing, at any time, the expected amount of available resources 196 (discounting the possibility of failures in the future). 198 Starting time (start-time): This value indicates when the scheduled 199 LSP is used and the corresponding LSP must be setup and active. 200 In other time (i.e., before the starting time or after the 201 starting time plus Duration), the LSP can be inactive to include 202 the possibility of the resources being used by other services. 204 Duration: This value indicates the length of time that the LSP is 205 undertaken by a traffic flow and the corresponding LSP must be 206 setup and active. At the end of which, the LSP is torn down and 207 removed from the database. 209 3. Motivation and Objectives 211 A stateful PCE [RFC8231] can support better efficiency by using LSP 212 scheduling described in the use case of [RFC8051]. This requires the 213 PCE to maintain the scheduled LSPs and their associated resource 214 usage, e.g. bandwidth for Packet-switched network, as well as have 215 the ability to trigger signaling for the LSP setup/tear-down at the 216 correct time. 218 Note that existing configuration tools can be used for LSP 219 scheduling, but as highlighted in section 3.1.3 of [RFC8231] as well 220 as discussions in [RFC8413], doing this as a part of PCEP in a 221 centralized manner, has obvious advantages. 223 This document provides a set of extensions to PCEP to enable LSP 224 scheduling for LSP creation/deletion under the stateful control of a 225 PCE and according to traffic service requests from customers, so as 226 to improve the usage of network resources. 228 4. Procedures and Mechanisms 230 4.1. LSP Scheduling Overview 232 The LSP scheduling allows PCEs and PCCs to provide scheduled LSP for 233 customers' traffic services at its actual usage time, so as to 234 improve the network resource utilization efficiency. 236 For stateful PCE supporting LSP scheduling, there are two types of 237 LSP databases used in this document. One is the LSP-DB defined in 238 PCEP [RFC8231], while the other is the scheduled LSP database (SLSP- 239 DB, see section 6). The SLSP-DB records scheduled LSPs and is used 240 in conjunction with the TED and LSP-DB. Note that the two types of 241 LSP databases can be implemented in one physical database or two 242 different databases. This is an implementation matter and this 243 document does not state any preference. 245 Furthermore, a scheduled TED can be generated from the scheduled LSP- 246 DB, LSP-DB and TED to indicate the network links and nodes with 247 resource availability information for now and future. The scheduled 248 TED MUST be maintained by all PCEs within the network environment. 250 In case of implementing PCC-initiated scheduled LSPs, when delegating 251 a scheduled LSP, a PCC MUST include its scheduling parameters (see 252 Section 5.2.1), including the starting time and the duration using 253 PCRpt message. Since the LSP is not yet signaled, at the time of 254 delegation the LSP would be in down state. Upon receiving the 255 delegation of the scheduled LSP, a stateful PCE MUST check whether 256 the parameters are valid. If they are valid, it SHALL check the 257 scheduled TED for the network resource availability on network nodes 258 and compute a path for the LSP with the scheduling information and 259 update to the PCC as per the active stateful PCE techniques 260 [RFC8231]. 262 Note that the active stateful PCE can update to the PCC with the path 263 for the scheduled LSP at any time. However, the PCC should not 264 signal the LSP over the path on receiving these messages since the 265 path is not active yet; PCC signals the LSP at the starting time. 267 In case of multiple PCEs within a single domain, the PCE would need 268 to synchronize their scheduling information with other PCEs within 269 the domain. This could be achieved by proprietary database 270 synchronization techniques or via a possible PCEP extension [I- 271 D.litkowski-pce-state-sync]. The technique used to synchronize SLSP- 272 DB is out of scope for this document. When the scheduling 273 information is out of synchronization among some PCEs, some of 274 scheduled LSPs may not be set up successfully. 276 The scheduled LSP can also be initiated by a PCE itself. In case of 277 implementing PCE-initiated scheduled LSP, the stateful PCE SHALL 278 check the network resource availability for the traffic and compute a 279 path for the scheduled LSP and initiate a scheduled LSP at the PCC 280 and synchronize the scheduled LSP to other PCEs. Note that, the PCC 281 could be notified immediately or at the starting time of the 282 scheduled LSP based on the local policy. In the former case, the 283 SCHED-LSP-ATTRIBUTE TLV (see Section 5.2.1) MUST be included in the 284 message whereas, for the latter the SCHED-LSP-ATTRIBUTE TLV SHOULD 285 NOT be included. Either way the synchronization to other PCEs MUST 286 be done when the scheduled LSP is created. 288 In both modes, for activation of scheduled LSPs, the PCC MUST 289 initiate the setup of scheduled LSP at the start time. Similarly on 290 scheduled usage expiry, the PCC MUST initiate the removal of the LSP 291 based on the Flag set in SCHED-LSP-ATTRIBUTE TLV. 293 4.2. Support of LSP Scheduling 295 4.2.1. LSP Scheduling 297 For a scheduled LSP, a user configures it with an arbitrary 298 scheduling duration from time Ta to time Tb, which may be represented 299 as [Ta, Tb]. 301 When an LSP is configured with arbitrary scheduling duration [Ta, 302 Tb], a path satisfying the constraints for the LSP in the scheduling 303 duration is computed and the LSP along the path is set up to carry 304 traffic from time Ta to time Tb. 306 4.2.2. Periodical LSP Scheduling 308 In addition to LSP Scheduling at an arbitrary time period, there are 309 also periodical LSP Scheduling. 311 A periodical LSP Scheduling means an LSP has multiple time intervals 312 and the LSP is set up to carry traffic in every time interval. It 313 has a scheduling duration such as [Ta, Tb], a number of repeats such 314 as 10 (repeats 10 times), and a repeat cycle/time interval such as a 315 week (repeats every week). The scheduling interval: "[Ta, Tb] 316 repeats n times with repeat cycle C" represents n+1 scheduling 317 intervals as follows: 319 [Ta, Tb], [Ta+C, Tb+C], [Ta+2C, Tb+2C], ..., [Ta+nC, Tb+nC] 321 When an LSP is configured with a scheduling interval such as "[Ta, 322 Tb] repeats 10 times with a repeat cycle a week" (representing 11 323 scheduling intervals), a path satisfying the constraints for the LSP 324 in every interval represented by the periodical scheduling interval 325 is computed once. Note that the path computed for one recurrence may 326 be different from the path for another recurrence. And then the LSP 327 along the path is set up to carry traffic in each of the scheduling 328 intervals. If there is no path satisfying the constraints for some 329 of the intervals, the LSP MUST NOT be set up at all. It MUST 330 generate a PCEP Error (PCErr) with Error-type = 29 (Path computation 331 failure) and Error-value = TBD7 (Path could not be found for some 332 intervals). 334 4.2.2.1. Elastic Time LSP Scheduling 336 In addition to the basic LSP scheduling at an arbitrary time period, 337 another option is elastic time intervals, which is represented as 338 within -P and Q, where P and Q is an amount of time such as 300 339 seconds. P is called elastic range lower bound and Q is called 340 elastic range upper bound. 342 For a simple time interval such as [Ta, Tb] with an elastic range, 343 elastic time interval: "[Ta, Tb] within -P and Q" means a time period 344 from (Ta+X) to (Tb+X), where -P <= X <= Q. Note that both Ta and Tb 345 are shifted by the same 'X'. 347 When an LSP is configured with elastic time interval "[Ta, Tb] within 348 -P and Q", a path is computed such that the path satisfies the 349 constraints for the LSP in the time period from (Ta+Xv) to (Tb+Xv) 350 and an optimization is performed on Xv from -P to Q. The 351 optimization makes [Ta+Xv, Tb+Xv] to be the time interval closest to 352 time interval [Ta, Tb] within the elastic range. The LSP along the 353 path is set up to carry traffic in the time period from (Ta+Xv) to 354 (Tb+Xv). 356 Similarly, for a recurrent time interval with an elastic range, 357 elastic time interval: "[Ta, Tb] repeats n times with repeat cycle C 358 within -P and Q" represents n+1 simple elastic time intervals as 359 follows: 361 [Ta+X0, Tb+X0], [Ta+C+X1, Tb+C+X1], ..., [Ta+nC+Xn, Tb+nC+Xn] 362 where -P <= Xi <= Q, i = 0, 1, 2, ..., n. 364 If a user wants to keep the same repeat cycle between any two 365 adjacent time intervals, elastic time interval: "[Ta, Tb] repeats n 366 times with repeat cycle C within -P and Q SYNC" may be used, which 367 represents n+1 simple elastic time intervals as follows: 369 [Ta+X, Tb+X], [Ta+C+X, Tb+C+X], ..., [Ta+nC+X, Tb+nC+X] 370 where -P <= X <= Q. 372 4.2.2.2. Grace Periods 374 Besides the stated time scheduling, a user may want to have some 375 grace periods (short for graceful time periods) for each or some of 376 the time intervals for the LSP. Two grace periods may be configured 377 for a time interval. One is the grace period before the time 378 interval, called grace-before, which extends the lifetime of the LSP 379 for grace-before (such as 30 seconds) before the time interval. The 380 other is the one after the time interval, called grace-after, which 381 extends the lifetime of the LSP for grace-after (such as 60 seconds) 382 after the time interval. 384 When an LSP is configured with a simple time interval such as [Ta, 385 Tb] with grace periods such as grace-before GB and grace-after GA, a 386 path is computed such that the path satisfies the constraints for the 387 LSP in the time period from Ta to Tb. The LSP along the path is set 388 up to carry traffic in the time period from (Ta-GB) to (Tb+GA). 389 During grace periods from (Ta-GB) to Ta and from Tb to (Tb+GA), the 390 LSP is up to carry traffic in best effort. 392 4.3. Scheduled LSP creation 394 In order to realize PCC-Initiated scheduled LSPs in a centralized 395 network environment, a PCC MUST separate the setup of an LSP into two 396 steps. The first step is to request/delegate and get an LSP but not 397 signal it over the network. The second step is to signal the 398 scheduled LSP over the LSRs (Label Switching Router) at its starting 399 time. 401 For PCC-Initiated scheduled LSPs, a PCC MUST delegate the scheduled 402 LSP by sending a path computation report (PCRpt) message by including 403 its demanded resources with the scheduling information to a stateful 404 PCE. Note the PCC MAY use the PCReq/PCRep with scheduling 405 information before delegating. 407 Upon receiving the delegation via PCRpt message, the stateful PCE 408 MUST compute a path for the scheduled LSP per its starting time and 409 duration based on the network resource availability stored in 410 scheduled TED (see Section 4.1). 412 The stateful PCE will send a PCUpd message with the scheduled path 413 information as well as the scheduled resource information for the 414 scheduled LSP to the PCC. The stateful PCE MUST update its local 415 scheduled LSP-DB and scheduled TED with the scheduled LSP and would 416 need to synchronize the scheduling information with other PCEs in the 417 domain. 419 For PCE-Initiated Scheduled LSP, the stateful PCE MUST compute a path 420 for the scheduled LSP per requests from network management systems 421 automatically based on the network resource availability in the 422 scheduled TED and send a PCInitiate message with the path information 423 back to the PCC. Based on the local policy, the PCInitiate message 424 could be sent immediately to ask the PCC to create a scheduled LSP 425 (as per this document) or the PCInitiate message could be sent at the 426 start time to the PCC to create a normal LSP (as per [RFC8281]). 428 For both PCC-Initiated and PCE-Initiated Scheduled LSPs: 430 o The stateful PCE MUST update its local scheduled LSP-DB and 431 scheduled TED with the scheduled LSP. Additionally, it MUST send 432 a PCRpt message with the scheduled LSP to its next hop PCE along 433 the path of the LSP, so as to achieve the scheduling traffic 434 engineering information synchronization. 436 o Upon receiving the PCUpd message or PCInitiate message for the 437 scheduled LSP from PCEs with a found path, the PCC determines that 438 it is a scheduled path for the LSP by the SCHED-LSP-ATTRIBUTE TLV 439 (see Section 5.2.1) or SCHED-PD-LSP-ATTRIBUTE TLV (see 440 Section 5.2.2) in the message, and does not trigger signaling for 441 the LSP setup on LSRs immediately. 443 o The stateful PCE MUST update the Scheduled LSP parameters on any 444 network events using the PCUpd message to PCC. These changes are 445 also synchronized to other PCEs. 447 o When it is time for the LSP to be set up (i.e., at the start 448 time), based on the value of the C flag for the scheduled TLV, 449 either the PCC MUST trigger the LSP to be signaled or the 450 delegated PCE MUST send a PCUpd message to the head end LSR 451 providing the updated path to be signaled (with A flag set to 452 indicate LSP activation). 454 4.4. Scheduled LSP Modifications 456 After a scheduled LSP is configured, a user may change its parameters 457 including the requested time as well as the bandwidth. For a 458 periodic scheduled LSP, its unused recurrences can be modified or 459 cancelled. For a scheduled LSP that is currently active, its 460 duration (the lifetime) can be reduced. 462 In the PCC-Initiated case, the PCC MUST send the PCE a PCRpt message 463 for the scheduled LSP with updated parameters as well as scheduled 464 information included in the SCHED-LSP-ATTRIBUTE TLV (see 465 Section 5.2.1) or SCHED-PD-LSP-ATTRIBUTE TLV (see Section 5.2.2) 466 carried in the LSP Object. The PCE SHOULD take the updated resources 467 and schedule into considerations and update the new path for the 468 scheduled LSP to the PCC as well as synchronize to other PCEs in the 469 network. In case path cannot be set based on new requirements, the 470 previous LSP will not be impacted and the same MUST be conveyed by 471 the use of empty ERO in the PCEP messages. 473 In the PCE-Initiated case, the Stateful PCE would recompute the path 474 based on updated parameters as well as scheduled information. In 475 case it has already conveyed to the PCC this information by sending a 476 PCInitiate message, it SHOULD update the path and other scheduling 477 and resource information by sending a PCUpd message. 479 4.5. Scheduled LSP activation and deletion 481 In the PCC-Initiated case, when it is time for the LSP to be set up 482 (i.e., at the start time), based on the value of the C flag for the 483 scheduled TLV, either the PCC MUST trigger the LSP to be signaled or 484 the delegated PCE MUST send a PCUpd message to the head end LSR 485 providing the updated path to be signaled (with A flag set to 486 indicate LSP activation). The PCC MUST report the status of the 487 active LSP as per the procedures in [RFC8231] and at this time the 488 LSP MUST be considered as part of the LSP-DB. The A flag MUST be set 489 in the scheduled TLV to indicate that the LSP is active now. After 490 the scheduled duration expires, based on the C flag, the PCC MUST 491 trigger the LSP deletion on itself or the delegated PCE MUST send a 492 PCUpd message to the PCC to delete the LSP as per the procedures in 493 [RFC8231]. 495 In the PCE-Initiated case, based on the local policy, if the 496 scheduled LSP is already conveyed to the PCC at the time of creation, 497 the handling of LSP activation and deletion is handled in the same 498 way as PCC-Initiated case as per the setting of C flag. Otherwise, 499 the PCE MUST send the PCInitiate message at the start time to the PCC 500 to create a normal LSP without the scheduled TLV and remove the LSP 501 after the duration expires as per [RFC8281]. 503 5. PCEP Objects and TLVs 505 5.1. Stateful PCE Capability TLV 507 A PCC and a PCE indicate their ability to support LSP scheduling 508 during their PCEP session establishment phase. For a multiple-PCE 509 environment, the PCEs SHOULD also establish a PCEP session and 510 indicate its ability to support LSP scheduling among PCEP peers. The 511 Open Object in the Open message contains the STATEFUL-PCE-CAPABILITY 512 TLV. Note that the STATEFUL-PCE-CAPABILITY TLV is defined in 513 [RFC8231] and updated in [RFC8281] and [RFC8232]". In this document, 514 we define a new flag bit B (SCHED-LSP-CAPABLITY) in the Flags field 515 of the STATEFUL-PCE-CAPABILITY TLV to indicate the support of LSP 516 scheduling and another flag bit PD (PD-LSP-CAPABLITY) to indicate the 517 support of LSP periodical scheduling. 519 B (LSP-SCHEDULING-CAPABILITY) - 1 bit [Bit Position - TBD3]: If set 520 to 1 by a PCC, the B Flag indicates that the PCC allows LSP 521 scheduling; if set to 1 by a PCE, the B Flag indicates that the 522 PCE is capable of LSP scheduling. The B bit MUST be set by both 523 PCEP peers in order to support LSP scheduling for path 524 computation. 526 PD (PD-LSP-CAPABLITY) - 1 bit: [Bit Position - TBD4] If set to 1 by 527 a PCC, the PD Flag indicates that the PCC allows LSP scheduling 528 periodically; if set to 1 by a PCE, the PD Flag indicates that the 529 PCE is capable of periodical LSP scheduling. Both the PD bit and 530 the B bit MUST be set to 1 by both PCEP peers in order to support 531 periodical LSP scheduling for path computation. If the PD bit or 532 B bit is 0, then the periodical LSP scheduling capability MUST be 533 ignored. 535 5.2. LSP Object 537 The LSP object is defined in [RFC8231]. This document adds an 538 optional SCHED-LSP-ATTRIBUTE TLV for normal LSP scheduling and an 539 optional SCHED-PD-LSP-ATTRIBUTE TLV for periodical LSP scheduling. 540 The LSP Object for a scheduled LSP MUST NOT include these two TLVs. 541 Only one scheduling, either normal or periodical, is allowed for a 542 scheduled LSP. 544 The presence of the SCHED-LSP-ATTRIBUTE TLV in the LSP object 545 indicates that this LSP is normal scheduling while the SCHED-PD-LSP- 546 ATTRIBUTE TLV indicates that this scheduled LSP is periodical. The 547 SCHED-LSP-ATTRIBUTE TLV MUST be present in LSP Object for each normal 548 scheduled LSP carried in the PCEP messages. The SCHED-PD-LSP- 549 ATTRIBUTE TLV MUST be used in the LSP Object for each periodic 550 scheduled LSP carried in the PCEP messages. 552 Only one SCHED-LSP-ATTRIBUTE TLV SHOULD be present in the LSP object. 553 In case more than one SCHED-LSP-ATTRIBUTE TLV is found, the first 554 instance is processed and others ignored. The SCHED-PD-LSP-ATTRIBUTE 555 TLV is the same as the SCHED-LSP-ATTRIBUTE TLV regarding to its 556 presence in the LSP object. 558 5.2.1. SCHED-LSP-ATTRIBUTE TLV 560 The SCHED-LSP-ATTRIBUTE TLV MAY be included as an optional TLV within 561 the LSP object for LSP scheduling for the requesting traffic service. 563 This TLV MUST NOT be included unless both PCEP peers have set the B 564 (LSP-SCHEDULING-CAPABILITY) bit in STATEFUL-PCE-CAPABILITY TLV 565 carried in the Open message to one. If the TLV is received by a peer 566 when both peers didn't set the B bit to one, the peer MUST generate a 567 PCEP Error (PCErr) with a PCEP-ERROR object having Error-type = 19 568 (Invalid Operation) and Error-value = TBD6 (Attempted LSP Scheduling 569 if the scheduling capability was not advertised). 571 The format of the SCHED-LSP-ATTRIBUTE TLV is shown in Figure 1. 573 0 1 2 3 574 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 1 575 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 576 | Type (TBD1) | Length | 577 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 578 | Flags |R|C|A|G| Reserved (0) | 579 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 580 | Start-Time | 581 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 582 | Duration | 583 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 584 | GrB / Elastic-Lower-Bound | GrA / Elastic-Upper-Bound | 585 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 587 Figure 1: SCHED-LSP-ATTRIBUTE TLV 589 The type of the TLV is [TBD1] and the TLV has a fixed length of 16 590 octets. 592 The fields in the format are: 594 Flags (8 bits): The following flags are defined in this document 596 R (1 bit): Set to 1 to indicate the Start-Time is a relative 597 time, which is the number of seconds from the current time. 598 The PCEs and PCCs MUST synchronized their clocks when relative 599 time is used. It is RECOMMENDED that the Network Time Protocol 600 [RFC5905] be used to synchronize clocks among them. When the 601 transmission delay from a PCE or PCC to another PCE or PCC is 602 too big such as greater than 1 second, the scheduling interval 603 represented is not accurate if the delay is not considered. 604 Set to 0 to indicate that the 32-bit Start-Time is an absolute 605 time, which is the number of seconds since the epoch. The 606 epoch is 1 January 1970 at 00:00 UTC. It wraps around every 607 2^32 seconds, which is roughly 136 years. The next wraparound 608 will occur in the year 2106. The received Start-Time is 609 considered after the wraparound if the resulting value is less 610 than the current time. In which case, the value of the 32-bit 611 Start-Time is considered as the number of seconds from the time 612 of wraparound (because the Start-Time is always a future time). 614 C (1 bit): Set to 1 to indicate the PCC is responsible to setup 615 and remove the scheduled LSP based on the Start-Time and 616 duration. The PCE holds these responsibilities when the bit is 617 set to zero. 619 A (1 bit): Set to 1 to indicate the scheduled LSP has been 620 activated and should be considered as part of LSP-DB (instead 621 of Scheduled LSP-DB). 623 G (1 bit): Set to 1 to indicate the Grace period is included in 624 the fields GrB/Elastic-Lower-Bound and GrA/Elastic-Upper-Bound; 625 set to 0 indicate the elastic range is included in the fields. 627 Reserved (24 bits): This field MUST be set to zero on transmission 628 and MUST be ignored on receipt. 630 Start-Time (32 bits): This value in seconds, indicates when the 631 scheduled LSP is used to carry traffic and the corresponding LSP 632 MUST be setup and activated. Note that the transmission delay 633 SHOULD be considered when R=1 and the value of Start-Time is 634 small. 636 Duration (32 bits): The value in seconds, indicates the duration 637 that the LSP is undertaken by a traffic flow and the corresponding 638 LSP MUST be up to carry traffic. At the expiry of this duration, 639 the LSP MUST be torn down and deleted. Value of 0 MUST NOT be 640 used in Duration since it does not make any sense. The value of 641 Duration SHOULD be greater than a constant MINIMUM-DURATION 642 seconds, where MINIMUM-DURATION is 5. 644 The Start-Time indicates a time at or before which the scheduled LSP 645 MUST be set up. The value of the Start-Time represents the number of 646 seconds since the epoch when R bit is set to 0. When R bit is set to 647 1, the value of the Start-Time represents the number of seconds from 648 the current time. 650 In addition, it contains G flag set to 1 and a non zero grace-before 651 and grace-after in the fields GrB/Elastic-Lower-Bound and GrA/ 652 Elastic-Upper-Bound if grace periods are configured. It includes G 653 flag set to 0 and a non zero elastic range lower bound and upper 654 bound in the fields if there is an elastic range configured. A TLV 655 can configure a non-zero grace period or elastic range, but it MUST 656 NOT provide both for an LSP. 658 o GrB (Grace-Before -16 bits): The grace period time length in 659 seconds before the starting time. 661 o GrA (Grace-After -16 bits): The grace period time length in 662 seconds after time interval [starting time, starting time + 663 duration]. 665 o Elastic-Lower-Bound (16 bits): The maximum amount of time in 666 seconds that time interval can shift to lower/left. 668 o Elastic-Upper-Bound (16 bits): The maximum amount of time in 669 seconds that time interval can shift to upper/right. 671 5.2.2. SCHED-PD-LSP-ATTRIBUTE TLV 673 The periodical LSP is a special case of LSP scheduling. The traffic 674 service happens in a series of repeated time intervals. The SCHED- 675 PD-LSP-ATTRIBUTE TLV can be included as an optional TLV within the 676 LSP object for this periodical LSP scheduling. 678 This TLV MUST NOT be included unless both PCEP peers have set the B 679 (LSP-SCHEDULING-CAPABILITY) bit and PD (PD-LSP-CAPABLITY) bit in 680 STATEFUL-PCE-CAPABILITY TLV carried in open message to one. If the 681 TLV is received by a peer when either (or both) bit is zero, the peer 682 MUST generate a PCEP Error (PCErr) with a PCEP-ERROR object having 683 Error-type = 19 (Invalid Operation) and Error-value = TBD6 ( 684 Attempted LSP Scheduling if the scheduling capability was not 685 advertised). 687 The format of the SCHED-PD-LSP-ATTRIBUTE TLV is shown in Figure 2. 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 (TBD2) | Length | 693 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 694 | Flags|R|C|A|G| Opt | NR | Reserved (0) | 695 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 696 | Start-Time | 697 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 698 | Duration | 699 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 700 | Repeat-time-length | 701 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 702 | GrB / Elastic-Lower-Bound | GrA / Elastic-Upper-Bound | 703 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 705 Figure 2: SCHED-PD-LSP-ATTRIBUTE TLV 707 The type of the TLV is [TBD2] and the TLV has a fixed length of 20 708 octets. The description, format and meaning of the Flags (R, C, A 709 and G bit), Start-Time, Duration, GrB, GrA, Elastic-Lower-Bound and 710 Elastic-Upper-Bound fields remain the same as in the SCHED-LSP- 711 ATTRIBUTE TLV. 713 The following fields are new : 715 Opt: (4 bits) Indicates options to repeat. When a PCE receives a 716 TLV with a unknown Opt value, it does not compute any path for the 717 LSP. It MUST generate a PCEP Error (PCErr) with a PCEP-ERROR 718 object having Error-type = 4 (Not supported object) and Error- 719 value = 4 (Unsupported parameter). 721 Opt = 1: repeat every day; 723 Opt = 2: repeat every week; 725 Opt = 3: repeat every month; 727 Opt = 4: repeat every year; 729 Opt = 5: repeat every Repeat-time-length. 731 NR: (12 bits) The number of repeats. During each repetition, LSP 732 carries traffic. 734 Reserved (8 bits): This field MUST be set to zero on transmission 735 and MUST be ignored on receipt. 737 Repeat-time-length: (32 bits) The time in seconds between the start- 738 time of one repetition and the start-time of the next repetition. 740 6. The PCEP Messages 742 6.1. The PCRpt Message 744 Path Computation State Report (PCRpt) is a PCEP message sent by a PCC 745 to a PCE to report the status of one or more LSPs as per [RFC8231]. 746 Each LSP State Report in a PCRpt message contains the actual LSP's 747 path, bandwidth, operational and administrative status, etc. An LSP 748 Status Report carried on a PCRpt message is also used in delegation 749 or revocation of control of an LSP to/from a PCE. In case of 750 scheduled LSP, a scheduled TLV MUST be carried in the LSP object and 751 the ERO conveys the intended path for the scheduled LSP. The 752 scheduled LSP MUST be delegated to a PCE. 754 6.2. The PCUpd Message 756 Path Computation Update Request (PCUpd) is a PCEP message sent by a 757 PCE to a PCC to update LSP parameters, on one or more LSPs as per 758 [RFC8231]. Each LSP Update Request on a PCUpd message contains all 759 LSP parameters that a PCE wishes to be set for a given LSP. In case 760 of scheduled LSP, a scheduled TLV MUST be carried in the LSP object 761 and the ERO conveys the intended path for the scheduled LSP. In case 762 no path can be found, an empty ERO is used. The A bit is used in 763 PCUpd message to indicate the activation of the scheduled LSP in case 764 the PCE is responsible for the activation (as per the C bit). 766 6.3. The PCInitiate Message 768 An LSP Initiate Request (PCInitiate) message is a PCEP message sent 769 by a PCE to a PCC to trigger LSP instantiation or deletion as per 770 [RFC8281]. In case of scheduled LSP, based on the local policy, PCE 771 MAY convey the scheduled LSP to the PCC by including a scheduled TLV 772 in the LSP object. Or the PCE would initiate the LSP only at the 773 start time of the scheduled LSP as per the [RFC8281] without the use 774 of scheduled TLVs. 776 6.4. The PCReq message 778 The Path Computation Request (PCReq) message is a PCEP message sent 779 by a PCC to a PCE to request a path computation [RFC5440] and it may 780 contain the LSP object [RFC8231] to identify the LSP for which the 781 path computation is requested. In case of scheduled LSP, a scheduled 782 TLV MUST be carried in the LSP object in PCReq message to request the 783 path computation based on scheduled TED and LSP-DB. A PCC MAY use 784 PCReq message to obtain the scheduled path before delegating the LSP. 785 The parameters of the LSP may be changed (refer to Section 4.4). 787 6.5. The PCRep Message 789 The Path Computation Reply (PCRep) message is a PCEP message sent by 790 a PCE to a PCC in reply to a path computation request [RFC5440] and 791 it may contain the LSP object [RFC8231] to identify the LSP for which 792 the path is computed. A PCRep message can contain either a set of 793 computed paths if the request can be satisfied, or a negative reply 794 if not. The negative reply may indicate the reason why no path could 795 be found. In case of scheduled LSP, a scheduled TLV MUST be carried 796 in the LSP object in PCRep message to indicate the path computation 797 based on scheduled TED and LSP-DB. A PCC and PCE MAY use PCReq and 798 PCRep message to obtain the scheduled path before delegating the LSP. 800 6.6. The PCErr Message 802 The Path Computation Error (PCErr) message is a PCEP message as 803 described in [RFC5440] for error reporting. The current document 804 defines new error values for several error types to cover failures 805 specific to scheduling and reuse the applicable error types and error 806 values of [RFC5440] and [RFC8231] wherever appropriate. 808 The PCEP extensions for scheduling MUST NOT be used if one or both 809 PCEP speakers have not set the corresponding bits in the STATEFUL- 810 PCE-CAPABILITY TLV in their respective OPEN message to ones. If the 811 PCEP speaker supports the extensions of this specification but did 812 not advertise this capability, then upon receipt of LSP object with 813 the scheduled TLV, it MUST generate a PCEP Error (PCErr) with Error- 814 type=19 (Invalid Operation) and error-value TBD6 (Attempted LSP 815 Scheduling if the scheduling capability was not advertised), and it 816 SHOULD ignore the TLV. As per Section 7.1 of [RFC5440], a legacy 817 PCEP implementation that does not understand this specification, 818 would consider a scheduled TLV as unknown and ignore them. 820 If the PCC decides that the scheduling parameters proposed in the 821 PCUpd/PCInitiate message are unacceptable, it MUST report this error 822 by including the LSP-ERROR-CODE TLV (Section 7.3.3 of [RFC8231]) with 823 LSP error-value = 4 "Unacceptable parameters" in the LSP object (with 824 the scheduled TLV) in the PCRpt message to the PCE. 826 The scheduled TLV MUST be included in the LSP object for the 827 scheduled LSPs, if the TLV is missing, the receiving PCEP speaker 828 MUST send a PCErr message with Error-type=6 (Mandatory Object 829 missing) and Error-value TBD5 (Scheduled TLV missing). 831 7. Implementation Status 833 [NOTE TO RFC EDITOR : This whole section and the reference to RFC 834 7942 is to be removed before publication as an RFC] 836 This section records the status of known implementations of the 837 protocol defined by this specification at the time of posting of this 838 Internet-Draft, and is based on a proposal described in [RFC7942]. 839 The description of implementations in this section is intended to 840 assist the IETF in its decision processes in progressing drafts to 841 RFCs. Please note that the listing of any individual implementation 842 here does not imply endorsement by the IETF. Furthermore, no effort 843 has been spent to verify the information presented here that was 844 supplied by IETF contributors. This is not intended as, and must not 845 be construed to be, a catalog of available implementations or their 846 features. Readers are advised to note that other implementations may 847 exist. 849 According to [RFC7942], "this will allow reviewers and working groups 850 to assign due consideration to documents that have the benefit of 851 running code, which may serve as evidence of valuable experimentation 852 and feedback that have made the implemented protocols more mature. 853 It is up to the individual working groups to use this information as 854 they see fit". 856 At the time of posting the -09 version of this document, there are no 857 known implementations of this mechanism. It is believed that two 858 vendors/organizations are considering prototype implementations, but 859 these plans are too vague to make any further assertions. 861 8. Security Considerations 863 This document defines LSP-SCHEDULING-CAPABILITY TLV and SCHED-LSP- 864 ATTRIBUTE TLV, the security considerations discussed in [RFC5440], 865 [RFC8231], and [RFC8281] continue to apply. In some deployments the 866 scheduling information could provide details about the network 867 operations that could be deemed as extra sensitive. Additionally, 868 snooping of PCEP messages with such data or using PCEP messages for 869 network reconnaissance may give an attacker sensitive information 870 about the operations of the network. A single PCEP message can now 871 instruct a PCC to set up and tear down an LSP every second for a 872 number of times. That single message could have a significant effect 873 on the network. Thus, such deployments SHOULD employ suitable PCEP 874 security mechanisms like TCP Authentication Option (TCP-AO) [RFC5925] 875 or [RFC8253], which [RFC8253] is considered a security enhancement 876 and thus is much better suited for the sensitive information. PCCs 877 may also need to apply some form of rate limit to the processing of 878 scheduled LSPs. 880 9. Manageability Consideration 882 9.1. Control of Function and Policy 884 The LSP-Scheduling feature MUST be controlled per tunnel by the 885 active stateful PCE, the values for parameters like starting time, 886 duration SHOULD be configurable by customer applications and based on 887 the local policy at PCE. The suggested default values for starting 888 time and duration are one day in seconds from the current time and 889 one year in seconds respectively. One day has 86,400 seconds. One 890 year has 31,536,000 seconds. 892 When configuring the parameters about time, a user SHOULD consider 893 leap-years and leap-seconds. If a scheduled LSP has a time interval 894 containing a leap-year, the duration of the LSP is 366 days plus the 895 rest of the interval. 897 9.2. Information and Data Models 899 An implementation SHOULD allow the operator to view the information 900 about each scheduled LSP defined in this document. To serve this 901 purpose, the PCEP YANG module [I-D.ietf-pce-pcep-yang] could be 902 extended. 904 9.3. Liveness Detection and Monitoring 906 Mechanisms defined in this document do not imply any new liveness 907 detection and monitoring requirements in addition to those already 908 listed in [RFC5440]. 910 9.4. Verify Correct Operations 912 Mechanisms defined in this document do not imply any new operation 913 verification requirements in addition to those already listed in 914 [RFC5440]. An implementation SHOULD allow a user to view the 915 information including status about a scheduled LSP through CLI. In 916 addition, it SHOULD check and handle the cases where there is a 917 significant time correction or a clock skew between PCC and PCE. 919 9.5. Requirements On Other Protocols 921 Mechanisms defined in this document do not imply any new requirements 922 on other protocols. 924 9.6. Impact On Network Operations 926 Mechanisms defined in this document do not have any impact on network 927 operations in addition to those already listed in [RFC5440]. 929 10. IANA Considerations 931 10.1. PCEP TLV Type Indicators 933 This document defines the following new PCEP TLVs. IANA maintains a 934 sub-registry "PCEP TLV Type Indicators" in the "Path Computation 935 Element Protocol (PCEP) Numbers" registry. IANA is requested to make 936 the following allocations from this sub-registry. 938 Value Meaning Reference 939 TBD1 SCHED-LSP-ATTRIBUTE This document 940 TBD2 SCHED-PD-LSP-ATTRIBUTE This document 942 10.1.1. Opt Field in SCHED-PD-LSP-ATTRIBUTE TLV 944 IANA is requested to create and maintain a new sub-registry named 945 "SCHED-PD-LSP-ATTRIBUTE TLV Opt field" within the "Path Computation 946 Element Protocol (PCEP) Numbers" registry. Initial values for the 947 sub-registry are given below. New values are assigned by Standards 948 Action [RFC8126]. 950 Value Name Reference 951 ----- ---- ---------- 952 0 Reserved 953 1 REPEAT-EVERY-DAY This document 954 2 REPEAT-EVERY-WEEK This document 955 3 REPEAT-EVERY-MONTH This document 956 4 REPEAT-EVERY-YEAR This document 957 5 REPEAT-EVERY-REPEAT-TIME-LENGTH This document 958 6-14 Unassigned 959 15 Reserved 961 10.1.2. Schedule TLVs Flag Field 963 IANA is requested to create a new sub-registry, named "Schedule TLVs 964 Flag Field", within the "Path Computation Element Protocol (PCEP) 965 Numbers" registry. New values are assigned by Standards Action 966 [RFC8126]. Each bit should be tracked with the following qualities: 968 o Bit number (counting from bit 0 as the most significant bit) 970 o Capability description 972 o Defining RFC 974 The following values are defined in this document: 976 Bit Description Reference 977 0-3 Unassigned 978 4 Relative Time (R-bit) This document 979 5 PCC Responsible (C-bit) This document 980 6 LSP Activated (A-bit) This document 981 7 Grace Period Included (G-bit) This document 983 10.2. STATEFUL-PCE-CAPABILITY TLV Flag field 985 This document defines new bits in the Flags field in the STATEFUL- 986 PCE-CAPABILITY TLV in the OPEN object. IANA maintains a sub-registry 987 "STATEFUL-PCE-CAPABILITY TLV Flag Field" in the "Path Computation 988 Element Protocol (PCEP) Numbers" registry. IANA is requested to make 989 the following allocations from this sub-registry. 991 The following values are defined in this document: 993 Bit Description Reference 994 TBD3 LSP-SCHEDULING-CAPABILITY (B-bit) This document 995 TBD4 PD-LSP-CAPABLITY (PD-bit) This document 997 10.3. PCEP-Error Object 999 IANA is requested to allocate the following new error types to the 1000 existing error values within the "PCEP-ERROR Object Error Types and 1001 Values" subregistry of the "Path Computation Element Protocol (PCEP) 1002 Numbers" registry: 1004 Error-Type Meaning 1005 6 Mandatory Object missing 1007 Error-value 1008 TBD5: Scheduled TLV missing 1010 19 Invalid Operation 1012 Error-value 1013 TBD6: Attempted LSP Scheduling if the scheduling 1014 capability was not advertised 1016 29 Path computation failure 1018 Error-value 1019 TBD7: Constraints could not be met for some intervals 1021 11. Acknowledgments 1023 The authors of this document would also like to thank Rafal Szarecki, 1024 Adrian Farrel, Cyril Margaria for the review and comments. 1026 12. References 1028 12.1. Normative References 1030 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 1031 Requirement Levels", BCP 14, RFC 2119, 1032 DOI 10.17487/RFC2119, March 1997, 1033 . 1035 [RFC5440] Vasseur, JP., Ed. and JL. Le Roux, Ed., "Path Computation 1036 Element (PCE) Communication Protocol (PCEP)", RFC 5440, 1037 DOI 10.17487/RFC5440, March 2009, 1038 . 1040 [RFC5905] Mills, D., Martin, J., Ed., Burbank, J., and W. Kasch, 1041 "Network Time Protocol Version 4: Protocol and Algorithms 1042 Specification", RFC 5905, DOI 10.17487/RFC5905, June 2010, 1043 . 1045 [RFC8126] Cotton, M., Leiba, B., and T. Narten, "Guidelines for 1046 Writing an IANA Considerations Section in RFCs", BCP 26, 1047 RFC 8126, DOI 10.17487/RFC8126, June 2017, 1048 . 1050 [RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 1051 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, 1052 May 2017, . 1054 [RFC8231] Crabbe, E., Minei, I., Medved, J., and R. Varga, "Path 1055 Computation Element Communication Protocol (PCEP) 1056 Extensions for Stateful PCE", RFC 8231, 1057 DOI 10.17487/RFC8231, September 2017, 1058 . 1060 [RFC8232] Crabbe, E., Minei, I., Medved, J., Varga, R., Zhang, X., 1061 and D. Dhody, "Optimizations of Label Switched Path State 1062 Synchronization Procedures for a Stateful PCE", RFC 8232, 1063 DOI 10.17487/RFC8232, September 2017, 1064 . 1066 [RFC8281] Crabbe, E., Minei, I., Sivabalan, S., and R. Varga, "Path 1067 Computation Element Communication Protocol (PCEP) 1068 Extensions for PCE-Initiated LSP Setup in a Stateful PCE 1069 Model", RFC 8281, DOI 10.17487/RFC8281, December 2017, 1070 . 1072 [RFC8413] Zhuang, Y., Wu, Q., Chen, H., and A. Farrel, "Framework 1073 for Scheduled Use of Resources", RFC 8413, 1074 DOI 10.17487/RFC8413, July 2018, 1075 . 1077 12.2. Informative References 1079 [I-D.ietf-detnet-architecture] 1080 Finn, N., Thubert, P., Varga, B., and J. Farkas, 1081 "Deterministic Networking Architecture", draft-ietf- 1082 detnet-architecture-13 (work in progress), May 2019. 1084 [I-D.ietf-pce-pcep-yang] 1085 Dhody, D., Hardwick, J., Beeram, V., and J. Tantsura, "A 1086 YANG Data Model for Path Computation Element 1087 Communications Protocol (PCEP)", draft-ietf-pce-pcep- 1088 yang-14 (work in progress), July 2020. 1090 [RFC5925] Touch, J., Mankin, A., and R. Bonica, "The TCP 1091 Authentication Option", RFC 5925, DOI 10.17487/RFC5925, 1092 June 2010, . 1094 [RFC7399] Farrel, A. and D. King, "Unanswered Questions in the Path 1095 Computation Element Architecture", RFC 7399, 1096 DOI 10.17487/RFC7399, October 2014, 1097 . 1099 [RFC7942] Sheffer, Y. and A. Farrel, "Improving Awareness of Running 1100 Code: The Implementation Status Section", BCP 205, 1101 RFC 7942, DOI 10.17487/RFC7942, July 2016, 1102 . 1104 [RFC8051] Zhang, X., Ed. and I. Minei, Ed., "Applicability of a 1105 Stateful Path Computation Element (PCE)", RFC 8051, 1106 DOI 10.17487/RFC8051, January 2017, 1107 . 1109 [RFC8253] Lopez, D., Gonzalez de Dios, O., Wu, Q., and D. Dhody, 1110 "PCEPS: Usage of TLS to Provide a Secure Transport for the 1111 Path Computation Element Communication Protocol (PCEP)", 1112 RFC 8253, DOI 10.17487/RFC8253, October 2017, 1113 . 1115 [RFC8402] Filsfils, C., Ed., Previdi, S., Ed., Ginsberg, L., 1116 Decraene, B., Litkowski, S., and R. Shakir, "Segment 1117 Routing Architecture", RFC 8402, DOI 10.17487/RFC8402, 1118 July 2018, . 1120 Appendix A. Contributors Addresses 1122 Dhruv Dhody 1123 Huawei 1124 Divyashree Techno Park, Whitefield 1125 Bangalore, Karnataka 560066 1126 India 1128 Email: dhruv.ietf@gmail.com 1130 Xufeng Liu 1131 Ericsson 1132 USA 1133 Email: xliu@kuatrotech.com 1135 Mehmet Toy 1136 Verizon 1137 USA 1138 Email: mehmet.toy@verizon.com 1140 Vic Liu 1141 China Mobile 1142 No.32 Xuanwumen West Street, Xicheng District 1143 Beijing, 100053 1144 China 1145 Email: liu.cmri@gmail.com 1147 Lei Liu 1148 Fujitsu 1149 USA 1150 Email: lliu@us.fujitsu.com 1152 Khuzema Pithewan 1153 Infinera 1154 Email: kpithewan@infinera.com 1156 Zitao Wang 1157 Huawei 1158 101 Software Avenue, Yuhua District 1159 Nanjing, Jiangsu 210012 1160 China 1162 Email: wangzitao@huawei.com 1164 Xian Zhang 1165 Huawei Technologies 1166 Research Area F3-1B, 1167 Huawei Industrial Base, 1168 Shenzhen, 518129, China 1170 Email: zhang.xian@huawei.com 1172 Authors' Addresses 1174 Huaimo Chen (editor) 1175 Futurewei 1176 Boston, MA 1177 USA 1179 Email: huaimo.chen@futurewei.com 1180 Yan Zhuang (editor) 1181 Huawei 1182 101 Software Avenue, Yuhua District 1183 Nanjing, Jiangsu 210012 1184 China 1186 Email: zhuangyan.zhuang@huawei.com 1188 Qin Wu 1189 Huawei 1190 101 Software Avenue, Yuhua District 1191 Nanjing, Jiangsu 210012 1192 China 1194 Email: bill.wu@huawei.com 1196 Daniele Ceccarelli 1197 Ericsson 1198 Via A. Negrone 1/A 1199 Genova - Sestri Ponente 1200 Italy 1202 Email: daniele.ceccarelli@ericsson.com