idnits 2.17.1 draft-raghu-pce-lsp-control-request-02.txt: Checking boilerplate required by RFC 5378 and the IETF Trust (see https://trustee.ietf.org/license-info): ---------------------------------------------------------------------------- No issues found here. Checking nits according to https://www.ietf.org/id-info/1id-guidelines.txt: ---------------------------------------------------------------------------- No issues found here. Checking nits according to https://www.ietf.org/id-info/checklist : ---------------------------------------------------------------------------- No issues found here. Miscellaneous warnings: ---------------------------------------------------------------------------- == The copyright year in the IETF Trust and authors Copyright Line does not match the current year -- The document date (March 10, 2017) is 2576 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(See RFCs 3967 and 4897 for information about using normative references to lower-maturity documents in RFCs) == Outdated reference: A later version (-21) exists of draft-ietf-pce-stateful-pce-18 == Outdated reference: A later version (-11) exists of draft-ietf-pce-pce-initiated-lsp-09 == Outdated reference: A later version (-23) exists of draft-ietf-pce-pcep-yang-01 == Outdated reference: A later version (-18) exists of draft-ietf-pce-pceps-11 Summary: 0 errors (**), 0 flaws (~~), 5 warnings (==), 1 comment (--). Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 2 PCE Working Group A. Raghuram 3 Internet-Draft A. Goddard 4 Intended status: Standards Track C. Yadlapalli 5 Expires: September 11, 2017 AT&T 6 J. Karthik 7 S. Sivabalan 8 J. Parker 9 Cisco Systems, Inc. 10 D. Dhody 11 Huawei Technologies 12 March 10, 2017 14 Ability for a stateful PCE to request and obtain control of a LSP 15 draft-raghu-pce-lsp-control-request-02 17 Abstract 19 The stateful Path Computation Element (PCE) communication Protocol 20 (PCEP) extensions provide stateful control of Multiprotocol Label 21 Switching (MPLS) Traffic Engineering Label Switched Paths (TE LSP) 22 via PCEP, for a model where a Path Computation Client (PCC) delegates 23 control over one or more locally configured LSPs to a stateful PCE. 24 There are use-cases in which a stateful PCE may wish to request and 25 obtain control of one or more LSPs from a PCC. This document 26 describes a simple extension to stateful PCEP to achieve such an 27 objective. 29 Requirements Language 31 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 32 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this 33 document are to be interpreted as described in [RFC2119]. 35 Status of This Memo 37 This Internet-Draft is submitted in full conformance with the 38 provisions of BCP 78 and BCP 79. 40 Internet-Drafts are working documents of the Internet Engineering 41 Task Force (IETF). Note that other groups may also distribute 42 working documents as Internet-Drafts. The list of current Internet- 43 Drafts is at http://datatracker.ietf.org/drafts/current/. 45 Internet-Drafts are draft documents valid for a maximum of six months 46 and may be updated, replaced, or obsoleted by other documents at any 47 time. It is inappropriate to use Internet-Drafts as reference 48 material or to cite them other than as "work in progress." 49 This Internet-Draft will expire on September 11, 2017. 51 Copyright Notice 53 Copyright (c) 2017 IETF Trust and the persons identified as the 54 document authors. All rights reserved. 56 This document is subject to BCP 78 and the IETF Trust's Legal 57 Provisions Relating to IETF Documents 58 (http://trustee.ietf.org/license-info) in effect on the date of 59 publication of this document. Please review these documents 60 carefully, as they describe your rights and restrictions with respect 61 to this document. Code Components extracted from this document must 62 include Simplified BSD License text as described in Section 4.e of 63 the Trust Legal Provisions and are provided without warranty as 64 described in the Simplified BSD License. 66 Table of Contents 68 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 69 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3 70 3. LSP Control Request Flag . . . . . . . . . . . . . . . . . . 4 71 4. Operation . . . . . . . . . . . . . . . . . . . . . . . . . . 4 72 5. Security Considerations . . . . . . . . . . . . . . . . . . . 5 73 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 5 74 6.1. SRP Object Flags . . . . . . . . . . . . . . . . . . . . 5 75 7. Manageability Considerations . . . . . . . . . . . . . . . . 6 76 7.1. Control of Function and Policy . . . . . . . . . . . . . 6 77 7.2. Information and Data Models . . . . . . . . . . . . . . . 6 78 7.3. Liveness Detection and Monitoring . . . . . . . . . . . . 6 79 7.4. Verify Correct Operations . . . . . . . . . . . . . . . . 6 80 7.5. Requirements On Other Protocols . . . . . . . . . . . . . 6 81 7.6. Impact On Network Operations . . . . . . . . . . . . . . 6 82 8. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 7 83 9. References . . . . . . . . . . . . . . . . . . . . . . . . . 7 84 9.1. Normative References . . . . . . . . . . . . . . . . . . 7 85 9.2. Informative References . . . . . . . . . . . . . . . . . 7 86 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 8 88 1. Introduction 90 Stateful PCEP extensions [I-D.ietf-pce-stateful-pce] specifies a set 91 of extensions to PCEP [RFC5440] to enable stateful control of TE LSPs 92 between and across PCEP sessions in compliance with [RFC4657]. It 93 includes mechanisms to effect LSP state synchronization between PCCs 94 and PCEs, delegation of control of LSPs to PCEs, and PCE control of 95 timing and sequence of path computations within and across PCEP 96 sessions. The stateful PCEP defines the following two useful network 97 operations: 99 o Delegation: As per [RFC8051], an operation to grant a PCE 100 temporary rights to modify a subset of LSP parameters on one or 101 more LSPs of a PCC. LSPs are delegated from a PCC to a PCE and 102 are referred to as "delegated" LSPs. 104 o Revocation: As per [I-D.ietf-pce-stateful-pce], an operation 105 performed by a PCC on a previously delegated LSP. Revocation 106 revokes the rights granted to the PCE in the delegation operation. 108 For Redundant Stateful PCEs (section 5.7.4. of [I-D.ietf-pce- 109 stateful-pce]), during a PCE failure, one of the redundant PCE could 110 request to take control over an LSP. The redundant PCEs MAY use a 111 local policy or a proprietary election mechanism to decide which PCE 112 would take control. In this case, a mechanism is needed for a 113 stateful PCE to request control of one or more LSPs from a PCC, so 114 that a newly elected primary PCE can request to take over control. 116 In case of virtualized PCEs (vPCE) running as virtual network 117 function (VNF), as the computation load in the network increases, a 118 new instance of vPCE could be instantiated to balance the current 119 load. The PCEs could use proprietary algorithm to decide which LSPs 120 to be assigned to the new vPCE. Thus having a mechanism for the PCE 121 to request control of some LSPs is needed. 123 In some deployments, the operator would like to use stateful PCE for 124 global optimization algorithms but would still like to keep the 125 control of the LSP at the PCC. In such cases, a stateful PCE could 126 request to take control during the global optimization and return the 127 delegation once done. 129 This specification provides a simple extension, by using this a PCE 130 can request control of one or more LSPs from any PCC over the 131 stateful PCEP channel. The procedures for granting and relinquishing 132 control of the LSPs are specified in accordance with the 133 specification [I-D.ietf-pce-stateful-pce]. 135 2. Terminology 137 The following terminologies are used in this document: 139 PCC: Path Computation Client. 141 PCE: Path Computation Element 143 PCEP: Path Computation Element communication Protocol. 145 PCRpt: Path Computation State Report message. 147 PCUpd: Path Computation Update Request message. 149 PLSP-ID: A PCEP-specific identifier for the LSP. 151 3. LSP Control Request Flag 153 The SRP object is defined in [I-D.ietf-pce-stateful-pce] and 154 included here for ease of reference. [Editor's Note - The figure 155 would be removed at the time of publication.] 157 0 1 2 3 158 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 1 159 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 160 | Flags |C|R| 161 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 162 | SRP-ID-number | 163 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 164 | | 165 // Optional TLVs // 166 | | 167 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 169 Figure 1: The SRP Object 171 A new flag, the "LSP Control Request Flag" (C), is introduced in the 172 Stateful PCE Request Parameters (SRP) object. On a PCUpd message, a 173 PCE sets the C Flag to 1 to indicate that, it wishes to gain control 174 of LSP(s). The LSP is identified by the LSP object. A PLSP-ID of 175 value other than 0 and 0xFFFFF is used to identify the LSP for which 176 the PCE requests control. The PLSP-ID value of 0 indicates that the 177 PCE is requesting control of all LSPs originating from the PCC that 178 it wishes to delegate. The flag has no meaning in the PCRpt and 179 PCInitiate message and SHOULD be set to 0 on transmission and MUST be 180 ignored on receipt. 182 4. Operation 184 During normal operation, a PCC that wishes to delegate the control of 185 an LSP sets the D Flag to 1 in all PCRpt messages pertaining to the 186 LSP. The PCE confirms the delegation by setting D Flag to 1 in all 187 PCUpd messages pertaining to the LSP. The PCC revokes the control of 188 the LSP from the PCE by setting D Flag to 0 in PCRpt messages 189 pertaining to the LSP. If the PCE wishes to relinquish the control 190 of the LSP, it sets D Flag to 0 in all PCUpd messages pertaining to 191 the LSP. 193 If a PCE wishes to gain control over an LSP, it sends a PCUpd message 194 with C Flag set to 1 in SRP object. The LSP for which the PCE 195 requests control is identified by the PLSP-ID. The PLSP-ID of 0 196 indicates that the PCE wants control over all LSPs originating from 197 the PCC. If the LSP(s) is/are already delegated to the PCE making 198 the request, the PCC ignores the C Flag. A PCC can decide to 199 delegate the control of the LSP at its own discretion. If the PCC 200 grants or denies the control, it sends PCRpt message with D Flag set 201 to 1 and 0 respectively in accordance with according with stateful 202 PCEP [I-D.ietf-pce-stateful-pce] . If the PCC does not grant the 203 control, it MAY choose to not respond, and the PCE may choose to 204 retry requesting the control preferably using exponentially 205 increasing timer. A PCE ignores the C Flag on the PCRpt message. 207 In case multiple PCEs request control over an LSP, and if the PCC is 208 willing to grant the control, the LSP MUST be delegated to only one 209 PCE chosen by the PCC based on its local policy. 211 It should be noted that a legacy implementation of PCC, that does not 212 understand the C flag in PCUpd message, would simply ignore the flag 213 and the request to grant control over the LSP. 215 5. Security Considerations 217 The security considerations listed in [I-D.ietf-pce-stateful-pce] 218 apply to this document as well. However, this document also 219 introduces a new attack vectors. An attacker may flood the PCC with 220 request to delegate all its LSPs at a rate which exceeds the PCC's 221 ability to process them, either by spoofing messages or by 222 compromising the PCE itself. The PCC can simply ignore these 223 messages with no extra actions. Securing the PCEP session using 224 mechanism like TCP Authentication Option (TCP-AO) [RFC5925] or 225 Transport Layer Security (TLS) [I-D.ietf-pce-pceps] is RECOMMENDED. 227 6. IANA Considerations 229 This document requests IANA actions to allocate code points for the 230 protocol elements defined in this document. 232 6.1. SRP Object Flags 234 The SRP object is defined in [I-D.ietf-pce-stateful-pce] and the 235 registry to manage the Flag field of the SRP object is requested in 236 [I-D.ietf-pce-pce-initiated-lsp]. IANA is requested to make the 237 following allocation in the aforementioned registry. 239 Bit Description Reference 240 TBD (suggested value LSP Control Request Flag This document 241 30) (c-bit) 243 7. Manageability Considerations 245 All manageability requirements and considerations listed in [RFC5440] 246 and [I-D.ietf-pce-stateful-pce] apply to PCEP protocol extensions 247 defined in this document. In addition, requirements and 248 considerations listed in this section apply. 250 7.1. Control of Function and Policy 252 A PCE or PCC implementation SHOULD allow the operator to configure 253 the policy based on which it honor the request to control the LSPs. 254 Further, the operator MAY be to be allowed to trigger the LSP control 255 request at the PCE. 257 7.2. Information and Data Models 259 The PCEP YANG module [I-D.ietf-pce-pcep-yang] could be extended to 260 include mechanism to trigger the LSP control request. 262 7.3. Liveness Detection and Monitoring 264 Mechanisms defined in this document do not imply any new liveness 265 detection and monitoring requirements in addition to those already 266 listed in [RFC5440]. 268 7.4. Verify Correct Operations 270 Mechanisms defined in this document do not imply any new operation 271 verification requirements in addition to those already listed in 272 [RFC5440] and [I-D.ietf-pce-stateful-pce]. 274 7.5. Requirements On Other Protocols 276 Mechanisms defined in this document do not imply any new requirements 277 on other protocols. 279 7.6. Impact On Network Operations 281 Mechanisms defined in [RFC5440] and [I-D.ietf-pce-stateful-pce] also 282 apply to PCEP extensions defined in this document. Further, the 283 mechanism described in this document can help the operator to request 284 control of the LSPs at a particular PCE. 286 8. Acknowledgements 288 TBD. 290 9. References 292 9.1. Normative References 294 [I-D.ietf-pce-stateful-pce] 295 Crabbe, E., Minei, I., Medved, J., and R. Varga, "PCEP 296 Extensions for Stateful PCE", draft-ietf-pce-stateful- 297 pce-18 (work in progress), December 2016. 299 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 300 Requirement Levels", BCP 14, RFC 2119, 301 DOI 10.17487/RFC2119, March 1997, 302 . 304 [RFC5440] Vasseur, JP., Ed. and JL. Le Roux, Ed., "Path Computation 305 Element (PCE) Communication Protocol (PCEP)", RFC 5440, 306 DOI 10.17487/RFC5440, March 2009, 307 . 309 9.2. Informative References 311 [I-D.ietf-pce-pce-initiated-lsp] 312 Crabbe, E., Minei, I., Sivabalan, S., and R. Varga, "PCEP 313 Extensions for PCE-initiated LSP Setup in a Stateful PCE 314 Model", draft-ietf-pce-pce-initiated-lsp-09 (work in 315 progress), March 2017. 317 [I-D.ietf-pce-pcep-yang] 318 Dhody, D., Hardwick, J., Beeram, V., and j. 319 jefftant@gmail.com, "A YANG Data Model for Path 320 Computation Element Communications Protocol (PCEP)", 321 draft-ietf-pce-pcep-yang-01 (work in progress), October 322 2016. 324 [I-D.ietf-pce-pceps] 325 Lopez, D., Dios, O., Wu, W., and D. Dhody, "Secure 326 Transport for PCEP", draft-ietf-pce-pceps-11 (work in 327 progress), January 2017. 329 [RFC4657] Ash, J., Ed. and J. Le Roux, Ed., "Path Computation 330 Element (PCE) Communication Protocol Generic 331 Requirements", RFC 4657, DOI 10.17487/RFC4657, September 332 2006, . 334 [RFC5925] Touch, J., Mankin, A., and R. Bonica, "The TCP 335 Authentication Option", RFC 5925, DOI 10.17487/RFC5925, 336 June 2010, . 338 [RFC8051] Zhang, X., Ed. and I. Minei, Ed., "Applicability of a 339 Stateful Path Computation Element (PCE)", RFC 8051, 340 DOI 10.17487/RFC8051, January 2017, 341 . 343 Authors' Addresses 345 Aswatnarayan Raghuram 346 AT&T 347 200 S Laurel Aevenue 348 Middletown, NJ 07748 349 USA 351 Email: ar2521@att.com 353 Al Goddard 354 AT&T 355 200 S Laurel Aevenue 356 Middletown, NJ 07748 357 USA 359 Email: ag6941@att.com 361 Chaitanya Yadlapalli 362 AT&T 363 200 S Laurel Aevenue 364 Middletown, NJ 07748 365 USA 367 Email: cy098d@att.com 369 Jay Karthik 370 Cisco Systems, Inc. 371 125 High Street 372 Boston, Massachusetts 02110 373 USA 375 Email: jakarthi@cisco.com 376 Siva Sivabalan 377 Cisco Systems, Inc. 378 2000 Innovation Drive 379 Kanata, Ontario K2K 3E8 380 Canada 382 Email: msiva@cisco.com 384 Jon Parker 385 Cisco Systems, Inc. 386 2000 Innovation Drive 387 Kanata, Ontario K2K 3E8 388 Canada 390 Email: jdparker@cisco.com 392 Dhruv Dhody 393 Huawei Technologies 394 Divyashree Techno Park, Whitefield 395 Bangalore, Karnataka 560066 396 India 398 Email: dhruv.ietf@gmail.com