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Miscellaneous warnings: ---------------------------------------------------------------------------- == The copyright year in the IETF Trust and authors Copyright Line does not match the current year -- The document date (September 10, 2013) is 3879 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) -- Looks like a reference, but probably isn't: '20' on line 1002 -- Looks like a reference, but probably isn't: '13' on line 958 -- Looks like a reference, but probably isn't: '4' on line 994 -- Looks like a reference, but probably isn't: '8' on line 996 -- Looks like a reference, but probably isn't: '19' on line 998 ** Downref: Normative reference to an Informational RFC: RFC 4427 Summary: 2 errors (**), 0 flaws (~~), 1 warning (==), 7 comments (--). Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 2 MPLS Working Group T. Cheung 3 Internet-Draft ETRI 4 Intended status: Standards Track A. D'Alessandro 5 Expires: March 14, 2014 Telecom Italia 6 H. van Helvoort 7 Huawei Technologies 8 September 10, 2013 10 PSC protocol updates for non-revertive operation 11 draft-cdh-mpls-tp-psc-non-revertive-01.txt 13 Abstract 15 This document optionally updates [RFC6378], "MPLS Transport Profile 16 (MPLS-TP) Linear Protection", to change non-revertive operation to be 17 aligned with the behavior defined in [RFC4427] and in an effort to 18 satisfy the ITU-T's protection switching requirements. An operator 19 command, Manual Switch to Working (MS-W) is also included to revert 20 traffic to the working path in non-revertive operation. 22 Status of This Memo 24 This Internet-Draft is submitted in full conformance with the 25 provisions of BCP 78 and BCP 79. 27 Internet-Drafts are working documents of the Internet Engineering 28 Task Force (IETF). Note that other groups may also distribute 29 working documents as Internet-Drafts. The list of current Internet- 30 Drafts is at http://datatracker.ietf.org/drafts/current/. 32 Internet-Drafts are draft documents valid for a maximum of six months 33 and may be updated, replaced, or obsoleted by other documents at any 34 time. It is inappropriate to use Internet-Drafts as reference 35 material or to cite them other than as "work in progress." 37 This Internet-Draft will expire on March 14, 2014. 39 Copyright Notice 41 Copyright (c) 2013 IETF Trust and the persons identified as the 42 document authors. All rights reserved. 44 This document is subject to BCP 78 and the IETF Trust's Legal 45 Provisions Relating to IETF Documents 46 (http://trustee.ietf.org/license-info) in effect on the date of 47 publication of this document. Please review these documents 48 carefully, as they describe your rights and restrictions with respect 49 to this document. Code Components extracted from this document must 50 include Simplified BSD License text as described in Section 4.e of 51 the Trust Legal Provisions and are provided without warranty as 52 described in the Simplified BSD License. 54 Table of Contents 56 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 57 1.1. Motivation for adding MS-W . . . . . . . . . . . . . . . 3 58 1.2. Behavior of MS-P and MS-W . . . . . . . . . . . . . . . . 3 59 1.3. Equal priority resolution . . . . . . . . . . . . . . . . 3 60 2. Conventions Used in This Document . . . . . . . . . . . . . . 4 61 3. Acronyms . . . . . . . . . . . . . . . . . . . . . . . . . . 4 62 4. Updates to the PSC RFC . . . . . . . . . . . . . . . . . . . 4 63 4.1. Updates to Section 2.1. Acronyms . . . . . . . . . . . . 4 64 4.2. Updates to Section 3.1. Local Request Logic . . . . . . . 5 65 4.3. Updates to Section 3.2. Remote Requests . . . . . . . . . 6 66 4.4. Updates to Section 3.6. PSC Control States . . . . . . . 6 67 4.5. Updates to Section 4.2.2. PSC Request Field . . . . . . . 7 68 4.6. Updates to Section 4.3.2. Priority of Inputs . . . . . . 7 69 4.7. Updates to Section 4.3.3.1. Normal State . . . . . . . . 9 70 4.8. Updates to Section 4.3.3.2. Unavailable State . . . . . . 11 71 4.9. Updates to Section 4.3.3.3. Protecting Administrative 72 State . . . . . . . . . . . . . . . . . . . . . . . . . . 12 73 4.10. Updates to Section 4.3.3.4. Protecting Failure State . . 15 74 4.11. Updates to Section 4.3.3.5. Wait-to-Restore State . . . . 16 75 4.12. Updates to Section 4.3.3.6. Do-not-Revert State . . . . . 17 76 4.13. Updates to Appendix A. PSC State Machine Tables . . . . . 19 77 5. Security considerations . . . . . . . . . . . . . . . . . . . 22 78 6. IANA considerations . . . . . . . . . . . . . . . . . . . . . 22 79 7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 22 80 8. Normative References . . . . . . . . . . . . . . . . . . . . 22 81 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 22 83 1. Introduction 85 Non-revertive mode of protection switching is defined in [RFC4427]. 86 In this mode, the traffic does not return to the working path when 87 switch-over requests are terminated. 89 However, PSC protocol defined in [RFC6378] supports this operation 90 only when recovering from a defect condition, but does not operate as 91 non-revertive when an operator's switch-over command such as Forced 92 Switch or Manual Switch is cleared. To be aligned with legacy 93 transport network behavior and [RFC4427], a node should go into the 94 Do-not-Revert (DNR) state not only when a failure condition on a 95 working path is cleared but also when an operator command requesting 96 switch-over is cleared. 98 Changing the non-revertive operation introduces necessity of a new 99 operator command to revert traffic to the working path when in DNR 100 state. Moreover, according to Section 4.3.3.6 (Do-not-Revert State) 101 in [RFC6378], "to revert back to Normal state, the administrator 102 SHALL issue a Lockout of protection command followed by a Clear 103 command." This requirement introduces the potential risk of an 104 unprotected situation while the Lockout of protection is in effect. 105 Manual Switch-over for recovery LSP/span command, defined in 106 [RFC4427] and also defined in [RFC5654], Requirement 83, as one of 107 the mandatory external commands, should be used for this purpose, but 108 is not included in [RFC6378]. 110 This document optionally updates [RFC6378] to change non-revertive 111 operation to be aligned with the behavior defined in [RFC4427] and to 112 meet the ITU-T's protection switching requirements, and add a new 113 operator command, Manual Switch to Working (MS-W) to avoid the 114 potential problem with the Lockout of protection command when the DNR 115 should be cleared. For the sake of clarity, Manual Switch (MS) 116 defined in [RFC6378] is renamed Manual Switch to Protection (MS-P). 118 1.1. Motivation for adding MS-W 120 Most of the operational interventions on working paths are executed 121 after operating a "Manual switch-over for normal traffic" switch 122 command that switches the normal traffic from the working path to the 123 protection path. This command will keep the traffic on the 124 protection path unless a "Manual switch-over for recovery LSP/span" 125 command is issued that switches the normal traffic back to the 126 working path. Using Lockout of protection command as currently 127 suggested in [RFC6378] may cause, in some circumstances, traffic 128 loss. 130 1.2. Behavior of MS-P and MS-W 132 The MS-P and MS-W commands SHALL have the same priority. If one of 133 these commands is already issued, and the other command is issued 134 afterwards, it SHALL be ignored. If two LERs are requesting opposite 135 operations simultaneously, i.e. one LER is sending MS-P while the 136 other LER is sending MS-W, the MS-W SHALL be considered to have a 137 higher priority than MS-P, and MS-P SHALL be ignored. 139 This behavior is described in Section 4.2 that proposes updates to 140 Section 3.1 "Local Request Logic" of [RFC6378]. 142 1.3. Equal priority resolution 144 [RFC6378] defines only one rule for equal priority condition in 145 Section 4.3.2 as "The remote message from the far-end LER is assigned 146 a priority just below the similar local input." In order to support 147 the manual switch behavior described in Section 1.2, additional rules 148 for equal priority resolution are required, and are described in 149 Section 4.6 that proposes updates to Section 4.3.2. "Priority of 150 Inputs" of [RFC6378]. 152 2. Conventions Used in This Document 154 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 155 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this 156 document are to be interpreted as described in [RFC2119]. 158 3. Acronyms 160 This draft uses the following acronyms: 162 MPLS-TP Transport Profile for MPLS 163 MS Manual Switch 164 MS-P Manual Switch to Protection 165 MS-W Manual Switch to Working 166 PSC Protection State Coordination Protocol 168 4. Updates to the PSC RFC 170 This section describes the changes required to change non-revertive 171 operation and add "Manual Switch to Working" operator command in the 172 PSC protocol defined in [RFC6378]. 174 The term "Manual Switch" and its acronym "MS" used in [RFC6378] are 175 replaced respectively by "Manual Switch to Protection" and "MS-P" by 176 this document to avoid confusion with "Manual Switch to Working" and 177 its acronym "MS-W". 179 Also, the term "Protecting administrative state" used in [RFC6378] is 180 replaced by "Switching administrative state" by this document to 181 include the case where traffic is switched back to the working path 182 by administrative Manual Switch to Working command. 184 4.1. Updates to Section 2.1. Acronyms 186 Replace the following bullet item: 188 MS Manual Switch 190 With: 192 MS-P Manual Switch to Protection 193 MS-W Manual Switch to Working 195 4.2. Updates to Section 3.1. Local Request Logic 197 Replace the following text in the bullet item for operator command: 199 The commands Forced Switch, Manual Switch, Clear, Lockout of 200 protection (defined in [RFC4427] as Forced switch-over, Manual 201 switch-over, Clear, and Lockout of recovery LSP/span, 202 respectively) MUST be supported. 204 With: 206 The commands Forced Switch, Manual Switch to Protection, Manual 207 Switch to Working, Clear, Lockout of protection (defined in 208 [RFC4427] as Forced switch-over for normal traffic, Manual switch- 209 over for normal traffic, Manual switch-over for recovery LSP/span, 210 Clear and Lockout of recovery LSP/span, respectively) MUST be 211 supported. 213 Replace the following bullet item in the local request list: 215 o Manual Switch (MS) - if the operator requested that traffic be 216 switched from the working path to the protection path. This is 217 only relevant if there is no currently active fault condition or 218 operator command. 220 With: 222 o Manual Switch to Protection (MS-P) - if the operator requested 223 that traffic be switched from the working path to the protection 224 path. This is only relevant if there is no currently active fault 225 condition or operator command. 227 o Manual Switch to Working (MS-W) - if the operator requested that 228 traffic be switched from the protection path to the working path. 229 This is only relevant if there is no currently active fault 230 condition or operator command. 232 Add the following text above the last paragraph: 234 The MS-P and MS-W commands SHALL have the same priority. If one 235 of these commands is already issued, and the other command is 236 issued afterwards, it SHALL be ignored. If two LERs are 237 requesting opposite operations simultaneously, i.e. one LER is 238 sending MS-P while the other LER is sending MS-W, the MS-W SHALL 239 be considered to have a higher priority than MS-P, and MS-P SHALL 240 be ignored. 242 4.3. Updates to Section 3.2. Remote Requests 244 Replace the following bullet item in the remote request list: 246 o Remote MS - indicates that the remote end point is operating under 247 an operator command to switch the traffic from the working path to 248 the protection path. 250 With: 252 o Remote MS-P - indicates that the remote end point is operating 253 under an operator command to switch the traffic from the working 254 path to the protection path. 256 o Remote MS-W - indicates that the remote end point is operating 257 under an operator command to switch the traffic from the 258 protection path to the working path. 260 Replace the following bullet item: 262 o Remote DNR - indicates that the remote end point has determined 263 that the failure condition has recovered and will continue 264 transporting traffic on the protection path due to operator 265 configuration that prevents automatic reversion to the Normal 266 state. 268 With: 270 o Remote DNR - indicates that the remote end point has determined 271 that the switch-over condition by administrative commands has 272 ceased or that the failure condition has recovered and will 273 continue transporting traffic on the protection path due to 274 operator configuration that prevents automatic reversion to the 275 Normal state. 277 4.4. Updates to Section 3.6. PSC Control States 279 Replace the following bullet item in the protection domain states 280 list: 282 o Protecting administrative state - The operator has issued a 283 command switching the user traffic to the protection path. 285 With: 287 o Switching administrative state - The operator has issued a command 288 switching the user traffic either from the working path to the 289 protection path or from the protection path to the working path. 291 4.5. Updates to Section 4.2.2. PSC Request Field 293 Replace the following bullet item in the request list: 295 o (5) Manual Switch - indicates that the transmitting end point has 296 switched traffic to the protection path as a result of an 297 administrative Manual Switch command. The FPath field SHALL 298 indicate that the working path is being blocked (i.e., FPath set 299 to 1), and the Path field SHALL indicate that user data traffic is 300 being transported on the protection path (i.e., Path set to 1). 302 With: 304 o (5) Manual Switch - indicates that the transmitting end point has 305 switched traffic to the protection path as a result of an 306 administrative Manual Switch to Protection (MS-P) command or to 307 the working path as a result of an administrative Manual Switch to 308 Working (MS-W) command. Two commands, MS-P and MS-W are 309 represented by the same Request Field value, but differentiated by 310 the FPath value. When traffic is switched to the protection path, 311 the FPath field SHALL indicate that the working path is being 312 blocked (i.e., FPath set to 1), and the Path field SHALL indicate 313 that user data traffic is being transported on the protection path 314 (i.e., Path set to 1). When traffic is switched to the working 315 path, the FPath field SHALL indicate that the protection path is 316 being blocked (i.e., FPath set to 0), and the Path field SHALL 317 indicate that user data traffic is being transported on the 318 working path (i.e., Path set to 0). 320 4.6. Updates to Section 4.3.2. Priority of Inputs 322 Replace the following number item: 324 8. Manual Switch (operator command) 326 With: 328 8. Manual Switch to Protection/Working (operator command) 330 Replace the following two paragraphs: 332 As was noted above, the Local Request logic SHALL always select 333 the local input indicator with the highest priority as the current 334 local request, i.e., only the highest priority local input will be 335 used to affect the control logic. All local inputs with lower 336 priority than this current local request will be ignored. 338 The remote message from the far-end LER is assigned a priority 339 just below the similar local input. For example, a remote Forced 340 Switch would have a priority just below a local Forced Switch but 341 above a local Signal Fail on protection input. As mentioned in 342 Section 3.6.1, the state transition is determined by the higher 343 priority input between the highest priority local input and the 344 remote message. This also determines the classification of the 345 state as local or remote. The following subsections detail the 346 transition based on the current state and the higher priority of 347 these two inputs. 349 With: 351 As was noted above, the Local Request logic SHALL always select 352 the local input indicator with the highest priority as the current 353 local request, i.e., only the highest priority local input will be 354 used to affect the control logic. All local inputs with lower 355 priority than this current local request will be ignored. For 356 local inputs with same priority, first-come, first-served rule is 357 applied. For example, once MS-P (or MS-W) local input is 358 determined as the highest priority local input, then subsequent 359 MS-W (or MS-P) local input will be ignored and automatically 360 canceled. 362 The remote message from the far-end LER is assigned a priority 363 just below the same local input. For example, a remote Forced 364 Switch would have a priority just below a local Forced Switch but 365 above a local Signal Fail on protection input. 367 However, if the LER is in a remote state due to a remote message, 368 a subsequent local input having the same priority but requesting 369 different action to the control logic, will be considered as 370 having lower priority than the remote message, and will be 371 ignored. For example, if the LER is in remote Switching 372 administrative status due to a remote MS-P, then subsequent local 373 MS-W will be ignored and automatically canceled. 375 It should be noted that there is a reverse case where one LER 376 receives a local command and the other LER receives, 377 simultaneously, a command with the same priority but requesting 378 different action. In this case, each of the two LERs receives a 379 subsequent remote message having the same priority but requesting 380 different action, while the LER is in a local state due to the 381 local input. In this case, a priority must be set for the 382 commands with the same priority regardless of its orgin (local 383 input or remote message). For example, one LER receives MS-P as a 384 local input and the other LER receives MS-W as a local input, 385 simultaneously. In this case, MS-W SHALL be considered as having 386 higher priority than MS-P at both LERs. 388 In order to resolve the equal priority conditions described above, 389 following rules are defined: 391 * If two local inputs having same priority but requesting 392 different action come to the Local Request logic, then the 393 input coming first SHALL be considered to have a higher 394 priority than the other coming later (first-come, first- 395 served). 397 * If the LER receives both a local input and a remote message 398 with the same priority and requesting the same action, i.e., 399 the same PSC Request Field and the same FPath value, then the 400 local input SHALL be considered to have a higher priority than 401 the remote message. 403 * If the LER receives both a local input and a remote message 404 with the same priority but requesting different actions, i.e., 405 the same PSC Request Field but different FPath value, then the 406 first-come, first-served rule SHALL be applied. If the remote 407 message comes first, then the state SHALL be a remote state and 408 subsequent local input is ignored. However, if the local input 409 comes first, the first-come, first-served rule cannot be 410 applied and must be viewed as simultaneous condition. This is 411 because the subsequent remote message will not be an 412 acknowledge of the local input by the far-end node. In this 413 case, the priority SHALL be determined by rules for each 414 simultaneous conditions. 416 * If the LER receives both MS-P and MS-W commands either as local 417 input or remote message and the LER is in a local Switching 418 administrative state, then the MS-W command SHALL be considered 419 to have a higher priority than the MS-P command. 421 As mentioned in Section 3.6.1, the state transition is determined 422 by the higher priority input between the highest priority local 423 input and the remote message. This also determines the 424 classification of the state as local or remote. The following 425 subsections detail the transition based on the current state and 426 the higher priority of these two inputs. 428 4.7. Updates to Section 4.3.3.1. Normal State 429 Replace the following bullet item in the reaction to local input 430 list: 432 o A local Forced Switch input SHALL cause the LER to go into local 433 Protecting administrative state and begin transmission of an 434 FS(1,1) message. 436 With: 438 o A local Forced Switch input SHALL cause the LER to go into local 439 Switching administrative state and begin transmission of an 440 FS(1,1) message. 442 Replace the following bullet item in the reaction to local input 443 list: 445 o A local Manual Switch input SHALL cause the LER to go into local 446 Protecting administrative state and begin transmission of an 447 MS(1,1) message. 449 With: 451 o A local Manual Switch Protection input SHALL cause the LER to go 452 into local Switching administrative state and begin transmission 453 of an MS(1,1) message. 455 o A local Manual Switch Working input SHALL cause the LER to go into 456 local Switching administrative state and begin transmission of an 457 MS(0,0) message. 459 Replace the following bullet item in the reaction to remote message 460 list: 462 o A remote Forced Switch message SHALL cause the LER to go into 463 remote Protecting administrative state and begin transmitting an 464 NR(0,1) message. 466 With: 468 o A remote Forced Switch message SHALL cause the LER to go into 469 remote Switching administrative state and begin transmitting an 470 NR(0,1) message. 472 Replace the following bullet item in the reaction to remote message 473 list: 475 o A remote Manual Switch message SHALL cause the LER to go into 476 remote Protecting administrative state, and transmit an NR(0,1) 477 message. 479 With: 481 o A remote Manual Switch to Protection message SHALL cause the LER 482 to go into remote Switching administrative state, and transmit an 483 NR(0,1) message. 485 o A remote Manual Switch to Working message SHALL cause the LER to 486 go into remote Switching administrative state, while continuing to 487 transmit the NR(0,0) message. 489 4.8. Updates to Section 4.3.3.2. Unavailable State 491 Replace the following bullet item in the reaction to local input 492 list: 494 o A local Forced Switch SHALL be ignored by the PSC Control logic 495 when in Unavailable state as a result of a (local or remote) 496 Lockout of protection. If in Unavailable state due to an SF on 497 protection, then the FS SHALL cause the LER to go into local 498 Protecting administrative state and begin transmitting an FS(1,1) 499 message. It should be noted that due to the unavailability of the 500 protection path (i.e., due to the SF condition) that this FS may 501 not be received by the far-end until the SF condition is cleared. 503 With: 505 o A local Forced Switch SHALL be ignored by the PSC Control logic 506 when in Unavailable state as a result of a (local or remote) 507 Lockout of protection. If in Unavailable state due to an SF on 508 protection, then the FS SHALL cause the LER to go into local 509 Switching administrative state and begin transmitting an FS(1,1) 510 message. It should be noted that due to the unavailability of the 511 protection path (i.e., due to the SF condition) that this FS may 512 not be received by the far-end until the SF condition is cleared. 514 Replace the following bullet item in the reaction to remote message 515 list: 517 o A remote Forced Switch message SHALL be ignored by the PSC Control 518 logic when in Unavailable state as a result of a (local or remote) 519 Lockout of protection. If in Unavailable state due to a local or 520 remote SF on protection, then the FS SHALL cause the LER to go 521 into remote Protecting administrative state; if in Unavailable 522 state due to local SF, begin transmitting an SF(0,1) message. 524 With: 526 o A remote Forced Switch message SHALL be ignored by the PSC Control 527 logic when in Unavailable state as a result of a (local or remote) 528 Lockout of protection. If in Unavailable state due to a local or 529 remote SF on protection, then the FS SHALL cause the LER to go 530 into remote Switching administrative state; if in Unavailable 531 state due to local SF, begin transmitting an SF(0,1) message. 533 4.9. Updates to Section 4.3.3.3. Protecting Administrative State 535 Replace the title of this section with "Switching Administrative 536 State". 538 Replace the following text in the first paragraph: 540 In the Protecting administrative state, the user data traffic 541 SHALL be transported on the protection path, while the working 542 path is blocked due to an operator command, i.e., Forced Switch or 543 Manual Switch. 545 With: 547 In the Switching administrative state, the user data traffic SHALL 548 be transported on either the protection path or working path, 549 depending on an operator command. If FS or MS-P command is in 550 effect, the working path is blocked and the traffic SHALL be 551 transported on the protection path. If MS-W command is in effect, 552 the protection path is blocked and the traffic SHALL be 553 transported on the working path. 555 Replace the reaction to local input list with: 557 o A local Clear SHALL be ignored if in remote Switching 558 administrative state. If in local Switching administrative state 559 due to local FS or MS-P, then this input SHALL cause the LER to go 560 into Normal state when the LER is configured for revertive 561 behavior, or Do-not-Revert State when the LER is configured for 562 non-revertive behavior. If in local Switching administrative 563 state due to local MS-W, then this input SHALL cause the LER to go 564 into Normal state. 566 o A local Lockout of protection input SHALL cause the LER to go into 567 local Unavailable state and begin transmission of an LO(0,0) 568 message. 570 o A local Forced Switch input SHALL cause the LER to remain in local 571 Switching administrative state and transmit an FS(1,1) message. 573 o A local Signal Fail indication on the protection path SHALL cause 574 the LER to go into local Unavailable state and begin transmission 575 of an SF(0,0) message, if the current state is due to a (local or 576 remote) MS-P or MS-W command. If the LER is in (local or remote) 577 Switching administrative state due to an FS situation, then the SF 578 on protection SHALL be ignored. 580 o A local Signal Fail indication on the working path SHALL cause the 581 LER to go into local Protecting failure state and begin 582 transmitting an SF(1,1) message, if the current state is due to a 583 (local or remote) MS-P or MS-W command. If the LER is in remote 584 Switching administrative state due to a remote Forced Switch 585 command, then this local indication SHALL cause the LER to remain 586 in remote Switching administrative state and transmit an SF(1,1) 587 message. If the LER is in local Switching administrative state 588 due to a local Forced Switch command, then this indication SHALL 589 be ignored (i.e., the indication should have been blocked by the 590 Local Request logic). 592 o A local Clear SF SHALL clear any local SF condition that may 593 exist. If in remote Switching administrative state, the LER SHALL 594 stop transmitting the SF(x,1) message and begin transmitting an 595 NR(0,1) message. 597 o A local Manual Switch to Protection input SHALL be ignored if in 598 remote Switching administrative state due to a remote Forced 599 Switch command. If the current state is due to a (local or 600 remote) Manual Switch to Protection operator command, it SHALL 601 cause the LER to remain in local Switching administrative state 602 and transmit an MS(1,1) message. If the current state is due to a 603 (local or remote) Manual Switch to Working operator command, the 604 local MS-P SHALL be ignored. 606 o A local Manual Switch to Working input SHALL be ignored if in 607 remote Switching administrative state due to a remote Forced 608 Switch command. If the current state is due to a (local or 609 remote) Manual Switch to Working operator command, it SHALL cause 610 the LER to remain in local Switching administrative state and 611 transmit an MS(0,0) message. If the current state is due to a 612 (local or remote) Manual Switch to Protection operator command, 613 the local MS-W SHALL be ignored. 615 o All other local inputs SHALL be ignored. 617 Replace the reaction to remote message list with: 619 o A remote Lockout of protection message SHALL cause the LER to go 620 into remote Unavailable state and begin transmitting an NR(0,0) 621 message. It should be noted that this automatically cancels the 622 current Forced Switch, Manual Switch to Protection or Manual 623 Switch to Working command and data traffic is reverted to the 624 working path, if required. 626 o A remote Forced Switch message SHALL be ignored by the PSC Process 627 logic if there is an active local Forced Switch operator command. 628 If the Switching administrative state is due to a remote Forced 629 Switch message, then the LER SHALL remain in remote Switching 630 administrative state and continue transmitting the last message. 631 If the Switching administrative state is due to either a local or 632 remote Manual Switch to Protection or Manual Switch to Working 633 command, then the LER SHALL remain in remote Switching 634 administrative state (updating the state information with the 635 proper relevant information) and begin transmitting an NR(0,1) 636 message. 638 o A remote Signal Fail message indicating a failure on the 639 protection path SHALL cause the LER to go into remote Unavailable 640 state and begin transmitting an NR(0,0) message, if the Switching 641 administrative state is due to a Manual Switch to Protection or 642 Manual Switch to Working command. It should be noted that this 643 automatically cancels the current Manual Switch to Protection or 644 Manual Switch to Working command, and data traffic is reverted to 645 the working path, if required. 647 o A remote Signal Fail message indicating a failure on the working 648 path SHALL be ignored if there is an active local Forced Switch 649 command. If the Switching administrative state is due to a local 650 or remote Manual Switch to Protection or Manual Switch to Working, 651 then the LER SHALL go to remote Protecting failure state and begin 652 transmitting an NR(0,1) message. 654 o A remote Manual Switch to Protection message SHALL be ignored by 655 the PSC Control logic if in Switching administrative state due to 656 a local or remote Forced Switch. If in Switching administrative 657 state due to a remote Manual Switch to Protection, then the LER 658 SHALL remain in remote Switching administrative state and continue 659 transmitting the current message. If in local Switching 660 administrative state due to an active Manual Switch to Protection, 661 then the LER SHALL remain in local Switching administrative state 662 and continue transmission of the MS(1,1) message. If in Switching 663 administrative state due to a remote MS-W, then the LER SHALL 664 remain in remote Switching administrative state, and begin 665 transmitting an NR(0,1) message. If in Switching administrative 666 state due to a local MS-W, then the remote MS-P message SHALL be 667 ignored. 669 o A remote Manual Switch to Working message SHALL be ignored by the 670 PSC Control logic if in Switching administrative state due to a 671 local or remote Forced Switch. If in Switching administrative 672 state due to a remote MS-W, then the LER SHALL remain in remote 673 Switching administrative state and continue transmission of an 674 NR(0,0) message. If in Switching administrative state due to a 675 local MS-W, then the remote MS-W message SHALL be ignored. If in 676 Switching administrative state due to a remote MS-P, then the LER 677 SHALL remain in remote Switching administrative state and begin 678 transmitting an NR(0,0) message. If in Switching administrative 679 state due to a local MS-P, then the LER SHALL go into remote 680 Switching administrative state and begin transmitting an NR(0,0) 681 message. It should be noted that this automatically cancels the 682 current MS-P command. 684 o A remote DNR(0,1) message SHALL be ignored if in local Switching 685 administrative state. If in remote Switching administrative state 686 due to a remote FS or MS-P, then the LER SHALL go to Do-not-Revert 687 state and continue transmitting an NR(0,1) message. If in remote 688 Switching administrative state due to a remote MS-W, then the 689 remote DNR message SHALL be ignored. 691 o A remote NR(0,0) message SHALL be ignored if in local Switching 692 administrative state. If in remote Switching administrative state 693 due to remote FS and there is no active local Signal Fail 694 indication, then the LER SHALL go into Normal state and begin 695 transmitting an NR(0,0) message. If there is a local Signal Fail 696 on the working path, the LER SHALL go into local Protecting 697 failure state and begin transmitting an SF(1,1) message. If in 698 remote Switching administrative state due to remote MS-P or MS-W, 699 then the LER SHALL go into Normal state and begin transmitting an 700 NR(0,0) message. If in local Switching administrative state due 701 to local MS-P or MS-W, then the remote NR(0,0) message SHALL be 702 ignored. 704 o All other remote messages SHALL be ignored. 706 4.10. Updates to Section 4.3.3.4. Protecting Failure State 708 Replace the following bullet item in the reaction to local input 709 list: 711 o A local Forced Switch input SHALL cause the LER to go into 712 Protecting administrative state and begin transmission of an 713 FS(1,1) message. 715 With: 717 o A local Forced Switch input SHALL cause the LER to go into 718 Switching administrative state and begin transmission of an 719 FS(1,1) message. 721 Replace the following bullet item in the reaction to remote message 722 list: 724 o A remote Forced Switch message SHALL cause the LER go into remote 725 Protecting administrative state, and if in local Protecting 726 failure state, the LER SHALL transmit the SF(1,1) message; 727 otherwise, it SHALL transmit NR(0,1). 729 With: 731 o A remote Forced Switch message SHALL cause the LER go into remote 732 Switching administrative state, and if in local Protecting failure 733 state, the LER SHALL transmit the SF(1,1) message; otherwise, it 734 SHALL transmit NR(0,1). 736 4.11. Updates to Section 4.3.3.5. Wait-to-Restore State 738 Replace the following bullet item in the reaction to local input 739 list: 741 o A local Forced Switch command SHALL send the Stop command to the 742 WTR timer, go into local Protecting administrative state, and 743 begin transmission of an FS(1,1) message. 745 With: 747 o A local Forced Switch command SHALL send the Stop command to the 748 WTR timer, go into local Switching administrative state, and begin 749 transmission of an FS(1,1) message. 751 Replace the following bullet item in the reaction to local input 752 list: 754 o A local Manual Switch input SHALL send the Stop command to the WTR 755 timer, go into local Protecting administrative state, and begin 756 transmission of an MS(1,1) message. 758 With: 760 o A local Manual Switch to Protection input SHALL send the Stop 761 command to the WTR timer, go into local Switching administrative 762 state, and begin transmission of an MS(1,1) message. 764 o A local Manual Switch to Working input SHALL send the Stop command 765 to the WTR timer, go into local Switching administrative state, 766 and begin transmission of an MS(0,0) message. 768 Replace the following bullet item in the reaction to remote message 769 list: 771 o A remote Forced Switch message SHALL send the Stop command to the 772 WTR timer, go into remote Protecting administrative state, and 773 begin transmission of an NR(0,1) message. 775 With: 777 o A remote Forced Switch message SHALL send the Stop command to the 778 WTR timer, go into remote Switching administrative state, and 779 begin transmission of an NR(0,1) message. 781 Replace the following bullet item in the reaction to remote message 782 list: 784 o A remote Manual Switch message SHALL send the Stop command to the 785 WTR timer, go into remote Protecting administrative state, and 786 begin transmission of an NR(0,1) message. 788 With: 790 o A remote Manual Switch to Protection message SHALL send the Stop 791 command to the WTR timer, go into remote Switching administrative 792 state, and begin transmission of an NR(0,1) message. 794 o A remote Manual Switch to Working message SHALL send the Stop 795 command to the WTR timer, go into remote Switching administrative 796 state, and begin transmission of an NR(0,0) message. 798 4.12. Updates to Section 4.3.3.6. Do-not-Revert State 800 Replace the first paragraph: 802 Do-not-Revert state is a continuation of the Protecting failure 803 state when the protection domain is configured for non-revertive 804 behavior. While in Do-not-Revert state, data traffic SHALL 805 continue to be transported on the protection path until the 806 administrator sends a command to revert to Normal state. It 807 should be noted that there is a fundamental difference between 808 this state and Normal -- whereas Forced Switch in Normal state 809 actually causes a switch in the transport path used, in Do-not- 810 Revert state, the Forced Switch just switches the state (to 811 Protecting administrative state) but the traffic would continue to 812 be transported on the protection path! To revert back to Normal 813 state, the administrator SHALL issue a Lockout of protection 814 command followed by a Clear command. 816 With: 818 Do-not-Revert state is a continuation of either the Protecting 819 failure state or Switching administrative state due to Forced 820 Switch or Manual Switch to Protection when the protection domain 821 is configured for non-revertive behavior. While in Do-not-Revert 822 state, data traffic SHALL continue to be transported on the 823 protection path until the administrator sends a command to revert 824 to Normal state. When the LER transitions into the Do-not-Revert 825 state, the PSC Control Process SHALL check the persistent state of 826 the local triggers to decide if it should further transition into 827 a new state. If the result of this check is a transition into a 828 new state, the LER SHALL transmit the corresponding message 829 described in this section and SHALL use the data path 830 corresponding to the new state. When the protection domain 831 remains in Do-not-Revert state, the end point SHALL transmit an 832 DNR(0,1) message if the state is local, or an NR(0,1) message if 833 the state is remote, indicating -- Nothing to report and data 834 traffic is being transported on the protection path. 836 Replace the following bullet item in the reaction to local input 837 list: 839 o A local Forced Switch command SHALL cause the LER to go into local 840 Protecting administrative state and begin transmission of an 841 FS(1,1) message. 843 With: 845 o A local Forced Switch command SHALL cause the LER to go into local 846 Switching administrative state and begin transmission of an 847 FS(1,1) message. 849 Replace the following bullet item in the reaction to local input 850 list: 852 o A local Manual Switch input SHALL cause the LER to go into local 853 Protecting administrative state and begin transmission of an 854 MS(1,1) message. 856 With: 858 o A local Manual Switch to Protection input SHALL cause the LER to 859 go into local Switching administrative state and begin 860 transmission of an MS(1,1) message. 862 o A local Manual Switch to Working input SHALL cause the LER to go 863 into local Switching administrative state and begin transmission 864 of an MS(0,0) message. 866 Replace the following bullet item in the reaction to remote message 867 list: 869 o A remote Forced Switch message SHALL cause the LER to go into 870 remote Protecting administrative state and begin transmission of 871 an NR(0,1) message. 873 With: 875 o A remote Forced Switch message SHALL cause the LER to go into 876 remote Switching administrative state and begin transmission of an 877 NR(0,1) message. 879 Replace the following bullet item in the reaction to remote message 880 list: 882 o A remote Manual Switch message SHALL cause the LER to go into 883 remote Protecting administrative state and begin transmission of 884 an NR(0,1) message. 886 With: 888 o A remote Manual Switch to Protection message SHALL cause the LER 889 to go into remote Switching administrative state and begin 890 transmission of an NR(0,1) message. 892 o A remote Manual Switch to Working message SHALL cause the LER to 893 go into remote Switching administrative state and begin 894 transmission of an NR(0,0) message. 896 4.13. Updates to Appendix A. PSC State Machine Tables 898 Modify the state machine as follows (only modified cells are shown): 900 Part 1: Local input state machine 902 +---------+------+---------+--------+--------+--------+-----+ 903 | | OC | LO | SF-P | FS | SF-W | SFc | 904 +---------+------+---------+--------+--------+--------+-----+ 905 | N | | | | SA:F:L | | | 906 | UA:LO:L | | | | | | | 907 | UA:P:L | | | | SA:F:L | | | 908 | UA:LO:R | | | | | | | 909 | UA:P:R | | | | SA:F:L | | | 910 | PF:W:L | | | | SA:F:L | | | 911 | PF:W:R | | | | SA:F:L | | | 912 | SA:F:L | [20] | | | | | | 913 | SA:MW:L | N | UA:LO:L | UA:P:L | SA:F:L | PF:W:L | i | 914 | SA:MP:L | [20] | | | SA:F:L | | | 915 | SA:F:R | | | | SA:F:L | | | 916 | SA:MW:R | i | UA:LO:L | UA:P:L | SA:F:L | PF:W:L | i | 917 | SA:MP:R | | | | SA:F:L | | | 918 | WTR | | | | SA:F:L | | | 919 | DNR | | | | SA:F:L | | | 920 +---------+------+---------+--------+--------+--------+-----+ 922 +---------+---------+---------+--------+ 923 | | MS-W | MS-P | WTRExp | 924 +---------+---------+---------+--------+ 925 | N | SA:MW:L | SA:MP:L | | 926 | UA:LO:L | i | | | 927 | UA:P:L | i | | | 928 | UA:LO:R | i | | | 929 | UA:P:R | i | | | 930 | PF:W:L | i | | | 931 | PF:W:R | i | | | 932 | SA:F:L | i | | | 933 | SA:MW:L | i | i | i | 934 | SA:MP:L | i | | | 935 | SA:F:R | i | | | 936 | SA:MW:R | SA:MW:L | i | i | 937 | SA:MP:R | i | SA:MP:L | | 938 | WTR | i | SA:MP:L | | 939 | DNR | SA:MW:L | SA:MP:L | | 940 +---------+---------+---------+--------+ 942 Part 2: Remote messages state machine 944 +---------+---------+--------+--------+------+---------+---------+ 945 | | LO | SF-P | FS | SF-W | MS-W | MS-P | 946 +---------+---------+--------+--------+------+---------+---------+ 947 | N | | | SA:F:R | | SA:MW:R | SA:MP:R | 948 | UA:LO:L | | | | | i | | 949 | UA:P:L | | | | | i | | 950 | UA:LO:R | | | | | i | | 951 | UA:P:R | | | SA:F:R | | i | | 952 | PF:W:L | | | SA:F:R | | i | | 953 | PF:W:R | | | SA:F:R | | i | | 954 | SA:F:L | | | | | i | | 955 | SA:MW:L | UA:LO:R | UA:P:R | SA:F:R | [13] | i | i | 956 | SA:MP:L | | | SA:F:R | | SA:MW:R | | 957 | SA:F:R | | | | | i | | 958 | SA:MW:R | UA:LO:R | UA:P:R | SA:F:R | [13] | i | SA:MP:R | 959 | SA:MP:R | | | SA:F:R | | SA:MW:R | | 960 | WTR | | | SA:F:R | | SA:MW:R | SA:MP:R | 961 | DNR | | | SA:F:R | | SA:MW:R | SA:MP:R | 962 +---------+---------+--------+--------+------+---------+---------+ 964 +---------+-----+-----+----+ 965 | | WTR | DNR | NR | 966 +---------+-----+-----+----+ 967 | N | | | | 968 | UA:LO:L | | | | 969 | UA:P:L | | | | 970 | UA:LO:R | | | | 971 | UA:P:R | | | | 972 | PF:W:L | | | | 973 | PF:W:R | | | | 974 | SA:F:L | | | | 975 | SA:MW:L | i | i | i | 976 | SA:MP:L | | | | 977 | SA:F:R | | | | 978 | SA:MW:R | i | i | i | 979 | SA:MP:R | | | | 980 | WTR | | | | 981 | DNR | | | | 982 +---------+-----+-----+----+ 984 Replace the following item in the footnotes for the table: 986 [4] Remain in the current state (PA:F:R) and transmit SF(1,1). 988 [8] Remain in PA:F:R and transmit NR(0,1). 990 [19] Transition to PA:F:R and send SF (0,1). 992 With: 994 [4] Remain in the current state (SA:F:R) and transmit SF(1,1). 996 [8] Remain in SA:F:R and transmit NR(0,1). 998 [19] Transition to SA:F:R and send SF(0,1). 1000 Add the following item in the footnotes for the table: 1002 [20] If domain configured for revertive behavior transition to N, 1003 else transition to DNR. 1005 5. Security considerations 1007 No specific security issue is raised in addition to those ones 1008 already documented in [RFC6378] 1010 6. IANA considerations 1012 This document makes no request of IANA. 1014 Note to RFC Editor: this section may be removed on publication as an 1015 RFC. 1017 7. Acknowledgements 1019 8. Normative References 1021 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 1022 Requirement Levels", BCP 14, RFC 2119, March 1997. 1024 [RFC4427] Mannie, E. and D. Papadimitriou, "Recovery (Protection and 1025 Restoration) Terminology for Generalized Multi-Protocol 1026 Label Switching (GMPLS)", RFC 4427, March 2006. 1028 [RFC5654] Niven-Jenkins, B., Brungard, D., Betts, M., Sprecher, N., 1029 and S. Ueno, "Requirements of an MPLS Transport Profile", 1030 RFC 5654, September 2009. 1032 [RFC6378] Weingarten, Y., Bryant, S., Osborne, E., Sprecher, N., and 1033 A. Fulignoli, "MPLS Transport Profile (MPLS-TP) Linear 1034 Protection", RFC 6378, October 2011. 1036 Authors' Addresses 1038 Taesik Cheung 1039 ETRI 1040 218 Gajeongno 1041 Yuseong-gu, Daejeon 305-700 1042 South Korea 1044 Phone: +82-42-860-5646 1045 Email: cts@etri.re.kr 1046 Alessandro D'Alessandro 1047 Telecom Italia 1048 via Reiss Romoli, 274 1049 Torino 10141 1050 Italy 1052 Phone: +39 011 2285887 1053 Email: alessandro.dalessandro@telecomitalia.it 1055 Huub van Helvoort 1056 Huawei Technologies 1057 Karspeldreef 4 1058 Amsterdam 1101 CJ 1059 The Netherlands 1061 Phone: +31 20 4300832 1062 Email: huub.van.helvoort@huawei.com