idnits 2.17.1 draft-li-ippm-otwamp-on-lag-03.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 (7 March 2022) is 780 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references to lower-maturity documents in RFCs) ** Downref: Normative reference to an Informational RFC: RFC 7799 == Outdated reference: A later version (-22) exists of draft-ietf-spring-segment-routing-policy-18 Summary: 1 error (**), 0 flaws (~~), 2 warnings (==), 1 comment (--). Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 2 Network Working Group Z. Li 3 Internet-Draft China Mobile 4 Intended status: Standards Track T. Zhou 5 Expires: 8 September 2022 Huawei 6 J. Guo 7 ZTE Corp. 8 G. Mirsky 9 Ericsson 10 R. Gandhi 11 Cisco 12 7 March 2022 14 One-way/Two-way Active Measurement Protocol Extensions for Performance 15 Measurement on LAG 16 draft-li-ippm-otwamp-on-lag-03 18 Abstract 20 This document defines extensions to One-way Active Measurement 21 Protocol (OWAMP), and Two-way Active Measurement Protocol (TWAMP) to 22 implement performance measurement on every member link of a Link 23 Aggregation Group (LAG). Knowing the measured metrics of each member 24 link of a LAG enables operators to enforce the performance based 25 traffic steering policy across the member links. 27 Requirements Language 29 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 30 "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and 31 "OPTIONAL" in this document are to be interpreted as described in 32 [RFC2119] [RFC8174] when, and only when, they appear in all capitals, 33 as shown here. 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 https://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 8 September 2022. 51 Copyright Notice 53 Copyright (c) 2022 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 (https://trustee.ietf.org/ 58 license-info) in effect on the date of publication of this document. 59 Please review these documents carefully, as they describe your rights 60 and restrictions with respect to this document. Code Components 61 extracted from this document must include Revised BSD License text as 62 described in Section 4.e of the Trust Legal Provisions and are 63 provided without warranty as described in the Revised BSD License. 65 Table of Contents 67 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 68 2. Micro Session on LAG . . . . . . . . . . . . . . . . . . . . 3 69 3. Mirco OWAMP Session . . . . . . . . . . . . . . . . . . . . . 4 70 3.1. Micro OWAMP-Control . . . . . . . . . . . . . . . . . . . 4 71 3.2. Micro OWAMP-Test . . . . . . . . . . . . . . . . . . . . 4 72 4. Mirco TWAMP Session . . . . . . . . . . . . . . . . . . . . . 5 73 4.1. Micro TWAMP-Control . . . . . . . . . . . . . . . . . . . 5 74 4.2. Micro TWAMP-Test . . . . . . . . . . . . . . . . . . . . 5 75 4.2.1. Sender Packet Format and Content . . . . . . . . . . 5 76 4.2.2. Sender Behavior . . . . . . . . . . . . . . . . . . . 7 77 4.2.3. Reflector Packet Format and Content . . . . . . . . . 8 78 4.2.4. Reflector Behavior . . . . . . . . . . . . . . . . . 11 79 5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 11 80 5.1. Mico OWAMP-Control Command . . . . . . . . . . . . . . . 11 81 5.2. Mico TWAMP-Control Command . . . . . . . . . . . . . . . 11 82 6. Security Considerations . . . . . . . . . . . . . . . . . . . 12 83 7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 12 84 8. References . . . . . . . . . . . . . . . . . . . . . . . . . 12 85 8.1. Normative References . . . . . . . . . . . . . . . . . . 12 86 8.2. Informative References . . . . . . . . . . . . . . . . . 12 87 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 13 89 1. Introduction 91 Link Aggregation Group (LAG), as defined in [IEEE802.1AX], provides 92 mechanisms to combine multiple physical links into a single logical 93 link. This logical link offers higher bandwidth and better 94 resiliency, because if one of the physical member links fails, the 95 aggregate logical link can continue to forward traffic over the 96 remaining operational physical member links. 98 Usually, when forwarding traffic over LAG, the hash-based mechanism 99 is used to load balance the traffic across the LAG member links. 100 Link delay of each member link varies because of different transport 101 paths. To provide low latency service for time sensitive traffic, we 102 need to explicitly steer the traffic across the LAG member links 103 based on the link delay, loss and so on. That requires a solution to 104 measure the performance metrics of every member link of a LAG. Hence 105 the measured performance metrics can work together with layer 2 106 bundle member link attributes advertisement [RFC8668] for traffic 107 steering. 109 OWAMP [RFC4656] and TWAMP [RFC5357] are two active measurement 110 methods according to the classification given in [RFC7799], which can 111 complement passive and hybrid methods. With both methods, running a 112 single test session over the aggregation without the knowledge of 113 each member link would make it impossible to measure the performance 114 of a given physical member link. The measured metrics can only 115 reflect the performance of one member link or an average of some/all 116 member links of the LAG. 118 This document extends OWAMP and TWAMP to implement performance 119 measurement on every member link of a LAG. The proposed method could 120 also potentially apply to layer 3 ECMP (Equal Cost Multi-Path), e.g., 121 with SR-Policy [I-D.ietf-spring-segment-routing-policy]. 123 2. Micro Session on LAG 125 This document intends to address the scenario (e.g., Figure 1) where 126 a LAG (e.g., the LAG includes four member links) directly connects 127 two nodes (A and B). The goal is to measure the performance of each 128 link of the LAG. 130 +---+ +---+ 131 | |-----------------------| | 132 | A |-----------------------| B | 133 | |-----------------------| | 134 | |-----------------------| | 135 +---+ +---+ 137 Figure 1: PM for LAG 139 To measure the performance metrics of every member link of a LAG, 140 multiple sessions (one session for each member link) need to be 141 established between the two end points that are connected by the LAG. 142 These sessions are called micro sessions in the remainder of this 143 document. 145 All micro sessions of a LAG share the same Sender IP Address and 146 Receiver IP Address. As for the UDP layer, the micro sessions may 147 share the same Sender Port and Receiver Port pair, or each micro 148 session is configured with a different Sender Port and Receiver Port 149 pair. But from the operational point of view, the former is simpler 150 and is RECOMMENDED. 152 The micro sessions need to associate with the corresponding member 153 links. For example, when the Server/Reflector/Receiver receives a 154 Test packet, it needs to know from which member link the packet is 155 received, and correlate it with a micro session. 157 This document defines new command types to indicate the set of micro 158 sessions of a LAG. The details are described in Sections 3 and 4 of 159 this document. Upon receiving a Test packet, the receiver uses the 160 receiving link's identifier to correlate the packet to a particular 161 micro session. In addition, Test packets MAY carry the member link 162 information for validation check. For example, when a micro Session- 163 Sender receives a reflected Test packet, it may need to check whether 164 the Test packet is from the expected member link. 166 3. Mirco OWAMP Session 168 This document assumes that the OWAMP Server and the OWAMP Receiver of 169 an OWAMP micro session are at the same end point. 171 3.1. Micro OWAMP-Control 173 To support the micro OWAMP session, a new command, Request-OW-Micro- 174 Sessions (TBD1), is defined in this document. The Request-OW-Micro- 175 Sessions command is based on the OWAMP Request-Session command, and 176 uses the message format as described in Section 3.5 of OWAMP 177 [RFC4656]. Test session creation of micro OWAMP session follows the 178 same procedure as defined in Section 3.5 of OWAMP [RFC4656] with the 179 following additions: 181 When an OWAMP Server receives a Request-OW-Micro-Sessions command, if 182 the request is accepted, the OWAMP Server MUST build a set of micro 183 sessions for all the member links of the LAG from which the Request- 184 OW-Micro-Sessions message is received. 186 3.2. Micro OWAMP-Test 188 Micro OWAMP-Test reuses the OWAMP-Test packet format and procedures 189 as defined in Section 4 of OWAMP [RFC4656] with the following 190 additions: 192 The micro OWAMP Sender MUST send the micro OWAMP-Test packets over 193 the member link with which the session is associated. When receives 194 a Test packet, the micro OWAMP receiver MUST use the member link from 195 which the Test packet is received to correlate the micro OWAMP 196 session. If there is no such a session, the Test packet MUST be 197 discarded. 199 4. Mirco TWAMP Session 201 As above, this document assumes that the TWAMP Server and the TWAMP 202 Session-Reflector of a micro OWAMP session are at the same end point. 204 4.1. Micro TWAMP-Control 206 To support the micro TWAMP session, a new command, Request-TW-Micro- 207 Sessions (TBD2), is defined in this document. The Request-TW-Micro- 208 Sessions command is based on the TWAMP Request-Session command, and 209 uses the message format as described in Section 3.5 of TWAMP 210 [RFC5357]. Test session creation of micro TWAMP session follows the 211 same procedure as defined in Section 3.5 of TWAMP [RFC5357] with the 212 following additions: 214 When a TWAMP Server receives a Request-TW-Micro-Sessions command, if 215 the request is accepted, the TWAMP Server MUST build a set of micro 216 sessions for all the member links of the LAG from which the Request- 217 TW-Micro-Sessions message is received. 219 4.2. Micro TWAMP-Test 221 The micro TWAMP-Test protocol is based on the TWAMP-Test protocol 222 [RFC5357] with the following extensions. 224 4.2.1. Sender Packet Format and Content 226 The micro TWAMP Session-Sender packet format is based on the TWAMP 227 Session-Sender packet format as defined in Section 4.1.2 of 228 [RFC5357]. Two new fields (Sender Micro-session ID and Reflector 229 Micro-session ID) are added to carry the LAG member link identifiers. 231 For unauthenticated mode, the format is as below: 233 0 1 2 3 234 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 1 235 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 236 | Sequence Number | 237 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 238 | Timestamp | 239 | | 240 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 241 | Error Estimate | MBZ | 242 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 243 | Sender Micro-session ID | Reflector Micro-session ID | 244 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 245 | | 246 . Packet Padding . 247 . . 248 | | 249 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 251 Figure 2: Micro Session-Sender Packet format in Unauthenticated Mode 253 For authenticated mode, the format is as below: 255 0 1 2 3 256 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 1 257 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 258 | Sequence Number | 259 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 260 | | 261 | MBZ (12 octets) | 262 | | 263 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 264 | Timestamp | 265 | | 266 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 267 | Error Estimate | MBZ | 268 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 269 | Sender Micro-session ID | Reflector Micro-session ID | 270 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 271 | | 272 | HMAC (16 octets) | 273 | | 274 | | 275 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 276 | | 277 . Packet Padding . 278 . . 279 | | 280 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 282 Figure 3: Micro Session-Sender Packet Format in Authenticated Mode 284 Except for the Sender/Reflector Micro-session ID field, all the other 285 fields are the same as defined in Section 4.1.2 of TWAMP [RFC5357], 286 which is defined in Section 4.1.2 of OWAMP [RFC4656]. Therefore, it 287 follows the same procedure and guidelines as defined in Section 4.1.2 288 of TWAMP [RFC5357]. 290 * Sender Micro-session ID (2-octets in length): it is defined to 291 carry the Micro-session identifier of the Sender side. The value 292 of the Sender Micro-session ID MUST be unique at the Session- 293 Sender. 295 * Reflector Micro-session ID (2-octets in length): it is defined to 296 carry the Micro-session identifier of the Reflector side. The 297 value of the Reflector Micro-session ID MUST be unique at the 298 Session-Reflector. 300 4.2.2. Sender Behavior 302 The micro TWAMP Session-Sender inherits the behaviors of the TWAMP 303 Session-Reflector as defined in Section 4.1 of [RFC5357]. In 304 addition, the micro TWAMP Session-Sender MUST send the micro TWAMP- 305 Test packets over the member link with which the session is 306 associated. 308 When sending the Test packet, the micro TWAMP Session-Sender MUST put 309 the Sender member link identifier that is associated with the micro 310 TWAMP session in the Sender Micro-session ID. If the Session-Sender 311 knows the Reflector member link identifier, the Reflector Micro- 312 session ID field (see Figure 2 and Figure 3) MUST be set. Otherwise, 313 the Reflector Micro-session ID field MUST be zero. 315 A Test packet with Sender member link identifier is sent to the 316 Session-Reflector, and then is reflected with the same Sender member 317 link identifier. So the Session-Sender can use the Sender member 318 link identifier to check whether a reflected Test packet is received 319 from the member link associated with the correct micro TWAMP session. 321 The Reflector member link identifier carried in the Reflector Micro- 322 session ID field is used by the Session-Receiver to check whether a 323 Test packet is received from the member link associated with the 324 correct micro TWAMP session. It means that the Session-Sender has to 325 learn the Reflector member link identifier. Once the Session-Sender 326 knows the Reflector member link identifier, it MUST put the 327 identifier in the Reflector Micro-session ID field (see Figure 2 or 328 Figure 3) of the Test packets that will be sent to the Session- 329 Reflector. The Reflector member link identifier can be obtained from 330 pre-configuration or learned from the data plane (e.g., the reflected 331 Test packet). How to obtain/learn the Reflector member link 332 identifier is out of the scope of this document. 334 When receiving a reflected Test packet, the micro TWAMP Session- 335 Sender MUST use the receiving member link to correlate the reflected 336 Test packet to a micro TWAMP session. If there is no such a session, 337 the reflected Test packet MUST be discarded. If a matched session 338 exists, the micro Session-Sender MUST use the Sender Micro-session ID 339 to validate whether the reflected Test packet is correctly 340 transmitted over the expected member link. If the validation fails, 341 the Test packet MUST be discarded. The micro Session-Sender MUST use 342 the Reflector Micro-session ID to validate the Reflector's behavior. 343 If the validation fails, the Test packet MUST be discarded. 345 4.2.3. Reflector Packet Format and Content 347 The micro TWAMP Session-Reflector packet format is based on the TWAMP 348 Session-Reflector packet format as defined in Section 4.2.1 of 349 [RFC5357]. Two new fields (Sender and Reflector Micro-session ID) 350 are added to carry the LAG member link identifiers. 352 For unauthenticated mode, the format is as below: 354 0 1 2 3 355 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 1 356 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 357 | Sequence Number | 358 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 359 | Timestamp | 360 | | 361 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 362 | Error Estimate | MBZ | 363 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 364 | Receive Timestamp | 365 | | 366 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 367 | Sender Sequence Number | 368 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 369 | Sender Timestamp | 370 | | 371 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 372 | Sender Error Estimate | Sender Micro-session ID | 373 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 374 | Sender TTL | MBZ | Reflector Micro-session ID | 375 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 376 | | 377 . . 378 . Packet Padding . 379 . . 380 | | 381 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 383 Figure 4: Micro Session-Reflector Packet Format in 384 Unauthenticated Mode 386 For authenticated mode, the format is as below: 388 0 1 2 3 389 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 1 390 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 391 | Sequence Number | 392 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 393 | MBZ (12 octets) | 394 | | 395 | | 396 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 397 | Timestamp | 398 | | 399 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 400 | Error Estimate | MBZ | 401 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 402 | Sender Micro-session ID | Reflector Micro-session ID | 403 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 404 | Receive Timestamp | 405 | | 406 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 407 | MBZ (8 octets) | 408 | | 409 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 410 | Sender Sequence Number | 411 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 412 | MBZ (12 octets) | 413 | | 414 | | 415 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 416 | Sender Timestamp | 417 | | 418 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 419 | Sender Error Estimate | | 420 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + 421 | MBZ (6 octets) | 422 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 423 | Sender TTL | | 424 +-+-+-+-+-+-+-+-+ + 425 | | 426 | | 427 | MBZ (15 octets) | 428 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 429 | HMAC (16 octets) | 430 | | 431 | | 432 | | 433 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 434 | | 435 . Packet Padding . 436 . . 437 | | 438 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 440 Figure 5: Micro Session-Reflector Packet Format in Authenticated Mode 442 Except for the Sender/Reflector Micro-session ID field, all the other 443 fields are the same as defined in Section 4.2.1 of TWAMP [RFC5357]. 444 Therefore, it follows the same procedure and guidelines as defined in 445 Section 4.2.1 of TWAMP [RFC5357]. 447 * Sender Micro-session ID (2-octets in length): it is defined to 448 carry the Micro-session identifier of the Sender side. The value 449 of the Sender Micro-session ID MUST be unique at the Session- 450 Sender. 452 * Reflector Micro-session ID (2-octets in length): it is defined to 453 carry the Micro-session identifier of the Reflector side. The 454 value of the Reflector Micro-session ID MUST be unique at the 455 Session-Reflector. 457 4.2.4. Reflector Behavior 459 The micro TWAMP Session-Reflector inherits the behaviors of a TWAMP 460 Session-Reflector as defined in Section 4.2 of [RFC5357]. 462 In addition, when receiving a Test packet, the micro TWAMP Session- 463 Reflector MUST use the receiving member link to correlate the Test 464 packet to a micro TWAMP session. If there is no such a session, the 465 Test packet MUST be discarded. If the Reflector Micro-session ID is 466 not zero, the Reflector MUST use the Reflector Micro-session ID to 467 validate whether it associates with the receiving member link. If 468 the validation fails, the Test packet MUST be discarded. 470 When sending a response to the received Test packet, the micro TWAMP 471 Session-Reflector MUST copy the Sender member link identifier from 472 the received Test packet and put it in the Sender Micro-session ID 473 field of the reflected Test packet (see Figure 4 and Figure 5). In 474 addition, the micro TWAMP Session-Reflector MUST fill the Reflector 475 Micro-session ID field (see Figure 2 and Figure 3) of the reflected 476 Test packet with the member link identifier that is associated with 477 the micro TWAMP session. 479 5. IANA Considerations 481 5.1. Mico OWAMP-Control Command 483 This document requires the IANA to allocate the following command 484 type from OWAMP-Control Command Number Registry. 486 Value Description Semantics Definition 487 TBD1 Request-OW-Micro-Sessions This document, Section 3.1 489 5.2. Mico TWAMP-Control Command 491 This document requires the IANA to allocate the following command 492 type from TWAMP-Control Command Number Registry. 494 Value Description Semantics Definition 495 TBD2 Request-TW-Micro-Sessions This document, Section 4.1 497 6. Security Considerations 499 This document does not introduce additional security requirements and 500 mechanisms other than those described in [RFC4656], and [RFC5357]. 502 7. Acknowledgements 504 The authors would like to thank Fang Xin, Henrik Nydell, Mach Chen, 505 Min Xiao, Jeff Tantsura for the valuable comments to this work. 507 8. References 509 8.1. Normative References 511 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 512 Requirement Levels", BCP 14, RFC 2119, 513 DOI 10.17487/RFC2119, March 1997, 514 . 516 [RFC4656] Shalunov, S., Teitelbaum, B., Karp, A., Boote, J., and M. 517 Zekauskas, "A One-way Active Measurement Protocol 518 (OWAMP)", RFC 4656, DOI 10.17487/RFC4656, September 2006, 519 . 521 [RFC5357] Hedayat, K., Krzanowski, R., Morton, A., Yum, K., and J. 522 Babiarz, "A Two-Way Active Measurement Protocol (TWAMP)", 523 RFC 5357, DOI 10.17487/RFC5357, October 2008, 524 . 526 [RFC7799] Morton, A., "Active and Passive Metrics and Methods (with 527 Hybrid Types In-Between)", RFC 7799, DOI 10.17487/RFC7799, 528 May 2016, . 530 [RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 531 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, 532 May 2017, . 534 [RFC8668] Ginsberg, L., Ed., Bashandy, A., Filsfils, C., Nanduri, 535 M., and E. Aries, "Advertising Layer 2 Bundle Member Link 536 Attributes in IS-IS", RFC 8668, DOI 10.17487/RFC8668, 537 December 2019, . 539 8.2. Informative References 541 [I-D.ietf-spring-segment-routing-policy] 542 Filsfils, C., Talaulikar, K., Voyer, D., Bogdanov, A., and 543 P. Mattes, "Segment Routing Policy Architecture", Work in 544 Progress, Internet-Draft, draft-ietf-spring-segment- 545 routing-policy-18, 17 February 2022, 546 . 549 [IEEE802.1AX] 550 IEEE Std. 802.1AX, "IEEE Standard for Local and 551 metropolitan area networks - Link Aggregation", November 552 2008. 554 Authors' Addresses 556 Zhenqiang Li 557 China Mobile 558 China 559 Email: li_zhenqiang@hotmail.com 561 Tianran Zhou 562 Huawei 563 China 564 Email: zhoutianran@huawei.com 566 Jun Guo 567 ZTE Corp. 568 China 569 Email: guo.jun2@zte.com.cn 571 Greg Mirsky 572 Ericsson 573 United States of America 574 Email: gregimirsky@gmail.com 576 Rakesh Gandhi 577 Cisco 578 Canada 579 Email: rgandhi@cisco.com