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Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 2 SPRING Working Group R. Gandhi, Ed. 3 Internet-Draft C. Filsfils 4 Intended status: Standards Track Cisco Systems, Inc. 5 Expires: February 7, 2021 D. Voyer 6 Bell Canada 7 M. Chen 8 Huawei 9 B. Janssens 10 Colt 11 August 6, 2020 13 Performance Measurement Using Simple TWAMP (STAMP) for Segment Routing 14 Networks 15 draft-gandhi-spring-stamp-srpm-02 17 Abstract 19 Segment Routing (SR) leverages the source routing paradigm. SR is 20 applicable to both Multiprotocol Label Switching (SR-MPLS) and IPv6 21 (SRv6) data planes. This document specifies procedure for sending 22 and processing probe query and response messages for Performance 23 Measurement (PM) in Segment Routing networks. The procedure uses the 24 mechanisms defined in RFC 8762 (Simple Two-Way Active Measurement 25 Protocol (STAMP)) for Delay Measurement, and uses the mechanisms 26 defined in this document for Loss Measurement. The procedure 27 specified is applicable to SR-MPLS and SRv6 data planes and is used 28 for both Links and end-to-end SR Paths including SR Policies. 30 Status of This Memo 32 This Internet-Draft is submitted in full conformance with the 33 provisions of BCP 78 and BCP 79. 35 Internet-Drafts are working documents of the Internet Engineering 36 Task Force (IETF). Note that other groups may also distribute 37 working documents as Internet-Drafts. The list of current Internet- 38 Drafts is at https://datatracker.ietf.org/drafts/current/. 40 Internet-Drafts are draft documents valid for a maximum of six months 41 and may be updated, replaced, or obsoleted by other documents at any 42 time. It is inappropriate to use Internet-Drafts as reference 43 material or to cite them other than as "work in progress." 45 This Internet-Draft will expire on February 7, 2021. 47 Copyright Notice 49 Copyright (c) 2020 IETF Trust and the persons identified as the 50 document authors. All rights reserved. 52 This document is subject to BCP 78 and the IETF Trust's Legal 53 Provisions Relating to IETF Documents 54 (https://trustee.ietf.org/license-info) in effect on the date of 55 publication of this document. Please review these documents 56 carefully, as they describe your rights and restrictions with respect 57 to this document. Code Components extracted from this document must 58 include Simplified BSD License text as described in Section 4.e of 59 the Trust Legal Provisions and are provided without warranty as 60 described in the Simplified BSD License. 62 Table of Contents 64 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3 65 2. Conventions Used in This Document . . . . . . . . . . . . . . 4 66 2.1. Requirements Language . . . . . . . . . . . . . . . . . . 4 67 2.2. Abbreviations . . . . . . . . . . . . . . . . . . . . . . 4 68 2.3. Reference Topology . . . . . . . . . . . . . . . . . . . 5 69 3. Overview . . . . . . . . . . . . . . . . . . . . . . . . . . 5 70 3.1. Example Provisioning Model . . . . . . . . . . . . . . . 6 71 4. Probe Messages . . . . . . . . . . . . . . . . . . . . . . . 7 72 4.1. Probe Query Message . . . . . . . . . . . . . . . . . . . 7 73 4.1.1. Delay Measurement Query Message . . . . . . . . . . . 7 74 4.1.2. Loss Measurement Query Message . . . . . . . . . . . 8 75 4.1.3. Probe Query for Links . . . . . . . . . . . . . . . . 9 76 4.1.4. Probe Query for SR Policy . . . . . . . . . . . . . . 9 77 4.1.5. Control Code Field Extension for STAMP Messages . . . 11 78 4.1.6. Loss Measurement Query Message Extensions . . . . . . 12 79 4.2. Probe Response Message . . . . . . . . . . . . . . . . . 15 80 4.2.1. One-way Measurement Mode . . . . . . . . . . . . . . 15 81 4.2.2. Two-way Measurement Mode . . . . . . . . . . . . . . 16 82 4.2.3. Loss Measurement Response Message Extensions . . . . 17 83 4.3. Node Address TLV Extensions . . . . . . . . . . . . . . . 20 84 4.4. Return Path TLV Extensions . . . . . . . . . . . . . . . 20 85 4.5. Additional Probe Message Processing Rules . . . . . . . . 22 86 4.5.1. TTL and Hop Limit . . . . . . . . . . . . . . . . . . 23 87 4.5.2. Router Alert Option . . . . . . . . . . . . . . . . . 23 88 4.5.3. UDP Checksum . . . . . . . . . . . . . . . . . . . . 23 89 5. Performance Measurement for P2MP SR Policies . . . . . . . . 23 90 6. ECMP Support for SR Policies . . . . . . . . . . . . . . . . 24 91 7. Performance Delay and Liveness Monitoring . . . . . . . . . . 25 92 8. Security Considerations . . . . . . . . . . . . . . . . . . . 25 93 9. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 26 94 10. References . . . . . . . . . . . . . . . . . . . . . . . . . 27 95 10.1. Normative References . . . . . . . . . . . . . . . . . . 27 96 10.2. Informative References . . . . . . . . . . . . . . . . . 27 97 Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . 31 98 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 31 100 1. Introduction 102 Segment Routing (SR) leverages the source routing paradigm and 103 greatly simplifies network operations for Software Defined Networks 104 (SDNs). SR is applicable to both Multiprotocol Label Switching (SR- 105 MPLS) and IPv6 (SRv6) data planes. SR takes advantage of the Equal- 106 Cost Multipaths (ECMPs) between source and transit nodes, between 107 transit nodes and between transit and destination nodes. SR Policies 108 as defined in [I-D.ietf-spring-segment-routing-policy] are used to 109 steer traffic through a specific, user-defined paths using a stack of 110 Segments. Built-in SR Performance Measurement (PM) is one of the 111 essential requirements to provide Service Level Agreements (SLAs). 113 The Simple Two-way Active Measurement Protocol (STAMP) provides 114 capabilities for the measurement of various performance metrics in IP 115 networks using probe messages [RFC8762]. It eliminates the need for 116 control-channel signaling by using configuration data model to 117 provision a test-channel (e.g. UDP paths). 118 [I-D.ietf-ippm-stamp-option-tlv] defines TLV extensions for STAMP 119 messages. 121 The STAMP message with a TLV for "direct measurement" can be used for 122 combined Delay + Loss measurement [I-D.ietf-ippm-stamp-option-tlv]. 123 However, in order to use only for loss measurement purpose, it 124 requires the node to support the delay measurement messages and 125 support timestamp for these messages (which may also require clock 126 synchronization). Furthermore, for hardware-based counter collection 127 for direct-mode loss measurement, the optional TLV based processing 128 adds unnecessary overhead (as counters are not at well-known 129 locations). 131 This document specifies procedures for sending and processing probe 132 query and response messages for Performance Measurement in SR 133 networks. The procedure uses the mechanisms defined in [RFC8762] 134 (STAMP) (including the TLV extensions) for Delay Measurement (DM), 135 and uses the mechanisms defined in this document for Loss Measurement 136 (LM). The procedure specified is applicable to SR-MPLS and SRv6 data 137 planes and is used for both Links and end-to-end SR Paths including 138 SR Policies and Flex-Algo IGP Paths. This document also defines 139 mechanisms for handling ECMPs of SR Paths for performance delay 140 measurement. Unless otherwise specified, the mechanisms defined in 141 [RFC8762] and [I-D.ietf-ippm-stamp-option-tlv] are not modified by 142 this document. 144 2. Conventions Used in This Document 146 2.1. Requirements Language 148 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 149 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this 150 document are to be interpreted as described in [RFC2119] [RFC8174] 151 when, and only when, they appear in all capitals, as shown here. 153 2.2. Abbreviations 155 BSID: Binding Segment ID. 157 DM: Delay Measurement. 159 ECMP: Equal Cost Multi-Path. 161 HMAC: Hashed Message Authentication Code. 163 LM: Loss Measurement. 165 MPLS: Multiprotocol Label Switching. 167 NTP: Network Time Protocol. 169 OWAMP: One-Way Active Measurement Protocol. 171 PM: Performance Measurement. 173 PSID: Path Segment Identifier. 175 PTP: Precision Time Protocol. 177 SID: Segment ID. 179 SL: Segment List. 181 SR: Segment Routing. 183 SRH: Segment Routing Header. 185 SR-MPLS: Segment Routing with MPLS data plane. 187 SRv6: Segment Routing with IPv6 data plane. 189 SSID: STAMP Session Identifier. 191 STAMP: Simple Two-way Active Measurement Protocol. 193 TC: Traffic Class. 195 2.3. Reference Topology 197 In the reference topology shown below, the sender node R1 initiates a 198 performance measurement probe query message and the reflector node R5 199 sends a probe response message for the query message received. The 200 probe response message is typically sent to the sender node R1. 202 SR is enabled on nodes R1 and R5. The nodes R1 and R5 may be 203 directly connected via a Link or there exists a Point-to-Point (P2P) 204 SR Path e.g. SR Policy [I-D.ietf-spring-segment-routing-policy] on 205 node R1 (called head-end) with destination to node R5 (called tail- 206 end). 208 t1 t2 209 / \ 210 +-------+ Query +-------+ 211 | | - - - - - - - - - ->| | 212 | R1 |=====================| R5 | 213 | |<- - - - - - - - - - | | 214 +-------+ Response +-------+ 215 \ / 216 t4 t3 217 Sender Reflector 219 Reference Topology 221 3. Overview 223 For one-way and two-way delay measurements in Segment Routing 224 networks, the probe messages defined in [RFC8762] are used. For 225 direct-mode and inferred-mode loss measurements, the messages defined 226 in this document are used. For both Links and end-to-end SR Paths 227 including SR Policies and Flex-Algo IGP Paths, no PM state for delay 228 or loss measurement need to be created on the reflector node R5. 230 Separate UDP destination port numbers are user-configured for delay 231 and loss measurements from the range specified in [RFC8762]. As 232 specified in [RFC8762], the reflector supports the destination UDP 233 port 862 for delay measurement probe messages by default. This UDP 234 port however, is not used for loss measurement probe messages defined 235 in this document. The sender uses the UDP port number following the 236 guidelines specified in Section 6 in [RFC6335]. The same destination 237 UDP port is used for Links and SR Paths and the reflector is unaware 238 if the query is for the Links or SR Paths. The number of UDP ports 239 with PM functionality needs to be minimized due to limited hardware 240 resoucres. 242 For Performance Measurement, probe query and response messages are 243 sent as following: 245 o For delay measurement, the probe messages are sent on the 246 congruent path of the data traffic by the sender node, and are 247 used to measure the delay experienced by the actual data traffic 248 flowing on the Links and SR Paths. 250 o For loss measurement, the probe messages are sent on the congruent 251 path of the data traffic by the sender node, and are used to 252 collect the receive traffic counters for the incoming link or 253 incoming SID where the probe query messages are received at the 254 reflector node (incoming link or incoming SID needed since the 255 reflector node does not have PM state present). 257 The In-Situ Operations, Administration, and Maintenance (IOAM) 258 mechanisms for SR-MPLS defined in [I-D.gandhi-mpls-ioam-sr] and for 259 SRv6 defined in [I-D.ali-spring-ioam-srv6] are used to carry PM 260 information such as timestamp in-band as part of the data packets, 261 and are outside the scope of this document. 263 3.1. Example Provisioning Model 265 An example of a provisioning model and typical measurement parameters 266 for each user-configured destination UDP port for performance delay 267 and loss measurements is shown in the following Figure 1: 269 +------------+ 270 | Controller | 271 +------------+ 272 Destination UDP Port / \ Destination UDP port 273 Measurement Protocol / \ Measurement Protocol 274 Measurement Type / \ Measurement Type 275 Delay/Loss / \ Delay/Loss 276 Authentication Mode & Key / \ Authentication Mode & Key 277 Timestamp Format / \ Loss Measurement Mode 278 Delay Measurement Mode / \ SSID (Wildcard) 279 Loss Measurement Mode / \ 280 v v 281 +-------+ +-------+ 282 | | | | 283 | R1 |============| R5 | 284 | | SR Path | | 285 +-------+ Or Link +-------+ 286 Sender Reflector 288 Figure 1: Example Provisioning Model 290 Example of Measurement Protocol is STAMP, example of the Timestamp 291 Format is PTPv2 [IEEE1588] or NTP and example of the Loss Measurement 292 mode is inferred-mode or direct-mode. 294 The mechanisms to provision the sender and reflector nodes are 295 outside the scope of this document. The provisioning model is not 296 used for signaling the PM parameters between the reflector and sender 297 nodes in SR networks. 299 The reflector node R5 uses the parameters for the timestamp format 300 and delay measurement mode (i.e. one-way or two-way mode) from the 301 received probe query message. 303 4. Probe Messages 305 4.1. Probe Query Message 307 The probe messages defined in [RFC8762] are used for delay 308 measurement for Links and end-to-end SR Paths including SR Policies. 309 For loss measurement, the probe messages defined in this document are 310 used. 312 The sender IPv4 or IPv6 address is used as the source address. The 313 reflector IPv4 or IPv6 address is used as the destination address. 314 In the case of SR Policy with IPv4 endpoint of 0.0.0.0 or IPv6 315 endpoint of ::0 [I-D.ietf-spring-segment-routing-policy], the address 316 in the range of 127/8 for IPv4 or ::FFFF:127/104 for IPv6 is used as 317 the destination address, respectively. 319 4.1.1. Delay Measurement Query Message 321 The message content for delay measurement probe query message using 322 UDP header [RFC0768] is shown in Figure 2. The DM probe query 323 message is sent with user-configured Destination UDP port number for 324 DM. The Destination UDP port cannot be used as Source port, since 325 the message does not have any indication to distinguish between the 326 query and response message. The payload of the DM probe query 327 message contains the delay measurement message defined in [RFC8762]. 329 +---------------------------------------------------------------+ 330 | IP Header | 331 . Source IP Address = Sender IPv4 or IPv6 Address . 332 . Destination IP Address = Reflector IPv4 or IPv6 Address . 333 . Protocol = UDP . 334 . . 335 +---------------------------------------------------------------+ 336 | UDP Header | 337 . Source Port = As chosen by Sender . 338 . Destination Port = User-configured Port for Delay Measurement. 339 . . 340 +---------------------------------------------------------------+ 341 | Payload = DM Message as specified in Section 4.2 of RFC 8762 | 342 . . 343 +---------------------------------------------------------------+ 345 Figure 2: DM Probe Query Message 347 Timestamp field is eight bytes and use the format defined in 348 Section 4.2.1 of [RFC8762]. It is recommended to use the IEEE 1588v2 349 Precision Time Protocol (PTP) truncated 64-bit timestamp format 350 [IEEE1588] as specified in [RFC8186], with hardware support in 351 Segment Routing networks. 353 4.1.1.1. Delay Measurement Authentication Mode 355 When using the authenticated mode for delay measurement, the matching 356 authentication type (e.g. HMAC-SHA-256) and key are user-configured 357 on both the sender and reflector nodes. A separate user-configured 358 destination UDP port is used for the delay measurement in 359 authentication mode due to the different probe message format. 361 4.1.2. Loss Measurement Query Message 363 The message content for loss measurement probe query message using 364 UDP header [RFC0768] is shown in Figure 3. The LM probe query 365 message is sent with user-configured Destination UDP port number for 366 LM, which is a different Destination UDP port number than DM. 367 Separate Destination UDP ports are used for direct-mode and inferred- 368 mode loss measurements. The Destination UDP port cannot be used as 369 Source port, since the message does not have any indication to 370 distinguish between the query and response message. The LM probe 371 query message contains the payload for loss measurement as defined in 372 Figure 7 and Figure 8. 374 +---------------------------------------------------------------+ 375 | IP Header | 376 . Source IP Address = Sender IPv4 or IPv6 Address . 377 . Destination IP Address = Reflector IPv4 or IPv6 Address . 378 . Protocol = UDP . 379 . . 380 +---------------------------------------------------------------+ 381 | UDP Header | 382 . Source Port = As chosen by Sender . 383 . Destination Port = User-configured Port for Loss Measurement . 384 . . 385 +---------------------------------------------------------------+ 386 | Payload = LM Message as specified in Figure 7 or 8 | 387 . . 388 +---------------------------------------------------------------+ 390 Figure 3: LM Probe Query Message 392 4.1.2.1. Loss Measurement Authentication Mode 394 When using the authenticated mode for loss measurement, the matching 395 authentication type (e.g. HMAC-SHA-256) and key are user-configured 396 on both the sender and reflector nodes. A separate user-configured 397 destination UDP port is used for the loss measurement in 398 authentication mode due to the different message format. 400 4.1.3. Probe Query for Links 402 The probe query message as defined in Figure 2 for delay measurement 403 and Figure 3 for loss measurement are used for Links which may be 404 physical, virtual or LAG (bundle), LAG (bundle) member, numbered/ 405 unnumbered Links. The probe messages are pre-routed over the Link 406 for both delay and loss measurement. 408 4.1.4. Probe Query for SR Policy 410 The performance delay and loss measurement for segment routing is 411 applicable to both end-to-end SR-MPLS and SRv6 Policies. 413 4.1.4.1. Probe Query Message for SR-MPLS Policy 415 The probe query messages for performance measurement of an end-to-end 416 SR-MPLS Policy is sent using its SR-MPLS header containing the MPLS 417 segment list as shown in Figure 4. 419 0 1 2 3 420 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 1 421 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 422 | Segment(1) | TC |S| TTL | 423 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 424 . . 425 . . 426 . . 427 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 428 | Segment(n) | TC |S| TTL | 429 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 430 | PSID | TC |S| TTL | 431 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 432 | Message as shown in Figure 2 for DM or Figure 3 for LM | 433 . . 434 +---------------------------------------------------------------+ 436 Figure 4: Example Probe Query Message for SR-MPLS Policy 438 The Segment List (SL) can be empty to indicate Implicit NULL label 439 case for a single-hop SR Policy. 441 The Path Segment Identifier (PSID) 442 [I-D.ietf-spring-mpls-path-segment] of the SR-MPLS Policy is used for 443 accounting received traffic on the egress node for loss measurement. 445 4.1.4.2. Probe Query Message for SRv6 Policy 447 An SRv6 Policy setup using the SRv6 Segment Routing Header (SRH) and 448 a Segment List as defined in [RFC8754]. The SRv6 network programming 449 is defined in [I-D.ietf-spring-srv6-network-programming]. The probe 450 query messages for performance measurement of an end-to-end SRv6 451 Policy is sent using its SRH with Segment List as shown in Figure 5. 452 The procedure defined for upper-layer header processing for SRv6 SIDs 453 in [I-D.ietf-spring-srv6-network-programming] is used to process the 454 UDP header in the received probe query messages. 456 +---------------------------------------------------------------+ 457 | IP Header | 458 . Source IP Address = Sender IPv6 Address . 459 . Destination IP Address = Destination IPv6 Address . 460 . . 461 +---------------------------------------------------------------+ 462 | SRH as specified in RFC 8754 | 463 . . 464 . . 465 +---------------------------------------------------------------+ 466 | IP Header (as needed) | 467 . Source IP Address = Sender IPv6 Address . 468 . Destination IP Address = Reflector IPv6 Address . 469 . . 470 +---------------------------------------------------------------+ 471 | UDP Header | 472 . Source Port = As chosen by Sender . 473 . Destination Port = User-configured Port . 474 . . 475 +---------------------------------------------------------------+ 476 | Payload = DM Message as specified in Section 4.2 of RFC 8762| | 477 . Payload = LM Message as specified in Figure 7 or 8 . 478 . . 479 +---------------------------------------------------------------+ 481 Figure 5: Example Probe Query Message for SRv6 Policy 483 4.1.5. Control Code Field Extension for STAMP Messages 485 In this document, the Control Code field is newly defined for delay 486 and loss measurement probe query messages for STAMP protocol in 487 unauthenticated and authenticated modes. The modified delay 488 measurement probe query message format is shown in Figure 6. This 489 message format is backwards compatible with the message format 490 defined in STAMP [RFC8762] as its reflector MUST ignore the received 491 field (previously identified as MBZ). With this field, the reflector 492 node does not require any additional SR state for PM (recall that in 493 SR networks, the state is in the probe packet and signaling of the 494 parameters is avoided). The usage of the Control Code is not limited 495 to the SR paths and can be used for non-SR paths in a network. 497 . . 498 . . 499 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 500 | Timestamp | 501 | | 502 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 503 | Error Estimate | SSID | 504 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 505 | MBZ |Se Control Code| 506 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 507 . . 508 . . 510 Figure 6: Sender Control Code in STAMP DM Message 512 Sender Control Code: Set as follows in STAMP probe query message. 514 In a Query: 516 0x0: Out-of-band Response Requested. Indicates that the probe 517 response is not required over the same path in the reverse 518 direction. This is also the default behavior. 520 0x1: In-band Response Requested. Indicates that this query has 521 been sent over a bidirectional path and the probe response is 522 required over the same path in the reverse direction. 524 0x2: No Response Requested. 526 4.1.6. Loss Measurement Query Message Extensions 528 In this document, STAMP probe query messages for loss measurement are 529 defined as shown in Figure 7 and Figure 8. The message formats are 530 hardware efficient due to well-known locations of the counters and 531 payload small in size. They are stand-alone and similar to the delay 532 measurement message formats (e.g. location of the Counter and 533 Timestamp). They also do not require backwards compatibility and 534 support for the existing DM message formats from [RFC8762] as 535 different user-configured destination UDP port is used for loss 536 measurement. 538 0 1 2 3 539 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 1 540 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 541 | Sequence Number | 542 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 543 | Transmit Counter | 544 | | 545 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 546 |X|B| Reserved | Block Number | SSID | 547 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 548 | MBZ |Se Control Code| 549 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 550 | | 551 | MBZ (24 octets) | 552 | | 553 | | 554 | | 555 | | 556 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 558 Figure 7: STAMP LM Probe Query Message - Unauthenticated Mode 560 0 1 2 3 561 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 1 562 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 563 | Sequence Number | 564 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 565 | MBZ (12 octets) | 566 | | 567 | | 568 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 569 | Transmit Counter | 570 | | 571 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 572 |X|B| Reserved | Block Number | SSID | 573 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 574 | MBZ |Se Control Code| 575 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 576 | MBZ (64 octets) | 577 . . 578 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 579 | | 580 | HMAC (16 octets) | 581 | | 582 | | 583 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 585 Figure 8: STAMP LM Probe Query Message - Authenticated Mode 587 Sequence Number (32-bit): As defined in [RFC8762]. 589 Transmit Counter (64-bit): The number of packets or octets sent by 590 the sender node in the query message and by the reflector node in the 591 response message. The counter is always written at the well-known 592 location in the probe query and response messages. 594 Receive Counter (64-bit): The number of packets or octets received at 595 the reflector node. It is written by the reflector node in the probe 596 response message. 598 Sender Counter (64-bit): This is the exact copy of the transmit 599 counter from the received query message. It is written by the 600 reflector node in the probe response message. 602 Sender Sequence Number (32-bit): As defined in [RFC8762]. 604 Sender TTL: As defined in Section 7.1. 606 LM Flags: The meanings of the Flag bits are: 608 X: Extended counter format indicator. Indicates the use of 609 extended (64-bit) counter values. Initialized to 1 upon creation 610 (and prior to transmission) of an LM query and copied from an LM 611 query to an LM response message. Set to 0 when the LM message is 612 transmitted or received over an interface that writes 32-bit 613 counter values. 615 B: Octet (byte) count. When set to 1, indicates that the Counter 616 1-4 fields represent octet counts. The octet count applies to all 617 packets within the LM scope, and the octet count of a packet sent 618 or received includes the total length of that packet (but excludes 619 headers, labels, or framing of the channel itself). When set to 620 0, indicates that the Counter fields represent packet counts. 622 Block Number (8-bit): The Loss Measurement using Alternate-Marking 623 method defined in [RFC8321] requires to color the data traffic. To 624 be able to correlate the transmit and receive traffic counters of the 625 matching color, the Block Number (or color) of the traffic counters 626 is carried by the probe query and response messages for loss 627 measurement. The Block Number can also be used to aggregate 628 performance metrics collected. 630 HMAC: The probe message in authenticated mode includes a key Hashed 631 Message Authentication Code (HMAC) [RFC2104] hash. Each probe query 632 and response messages are authenticated by adding Sequence Number 633 with Hashed Message Authentication Code (HMAC) TLV. It can use HMAC- 634 SHA-256 truncated to 128 bits (similarly to the use of it in IPSec 635 defined in [RFC4868]); hence the length of the HMAC field is 16 636 octets. 638 HMAC uses its own key and the mechanism to distribute the HMAC key is 639 outside the scope of this document. 641 In authenticated mode, only the sequence number is encrypted, and the 642 other payload fields are sent in clear text. The probe message MAY 643 include Comp.MBZ (Must Be Zero) variable length field to align the 644 packet on 16 octets boundary. 646 4.2. Probe Response Message 648 The probe response message is sent using the IP/UDP information from 649 the received probe query message. The content of the probe response 650 message is shown in Figure 9. 652 +---------------------------------------------------------------+ 653 | IP Header | 654 . Source IP Address = Reflector IPv4 or IPv6 Address . 655 . Destination IP Address = Source IP Address from Query . 656 . Protocol = UDP . 657 . . 658 +---------------------------------------------------------------+ 659 | UDP Header | 660 . Source Port = As chosen by Reflector . 661 . Destination Port = Source Port from Query . 662 . . 663 +---------------------------------------------------------------+ 664 | Payload = DM Message as specified in Section 4.3 of RFC 8762| | 665 . Payload = LM Message as specified in Figure 12 or 13 . 666 . . 667 +---------------------------------------------------------------+ 669 Figure 9: Probe Response Message 671 4.2.1. One-way Measurement Mode 673 In one-way measurement mode, the probe response message as defined in 674 Figure 9 is sent back out-of-band to the sender node, for both Links 675 and SR Policies. The Sender Control Code is set to "Out-of-band 676 Response Requested". In this delay measurement mode, as per 677 Reference Topology, all timestamps t1, t2, t3, and t4 are collected 678 by the probes. However, only timestamps t1 and t2 are used to 679 measure one-way delay as (t2 - t1). 681 4.2.2. Two-way Measurement Mode 683 In two-way measurement mode, when using a bidirectional path, the 684 probe response message as defined in Figure 9 is sent back to the 685 sender node on the congruent path of the data traffic on the same 686 reverse direction Link or associated reverse SR Policy 687 [I-D.ietf-pce-sr-bidir-path]. The Sender Control Code is set to "In- 688 band Response Requested". In this delay measurement mode, as per 689 Reference Topology, all timestamps t1, t2, t3, and t4 are collected 690 by the probes. All four timestamps are used to measure two-way delay 691 as ((t4 - t1) - (t3 - t2)). 693 Specifically, the probe response message is sent back on the incoming 694 physical interface where the probe query message is received. This 695 is required for example, in case of two-way measurement mode for Link 696 delay. 698 4.2.2.1. Probe Response Message for SR-MPLS Policy 700 The message content for sending probe response message for two-way 701 performance measurement of an end-to-end SR-MPLS Policy is shown in 702 Figure 10. 704 0 1 2 3 705 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 1 706 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 707 | Segment(1) | TC |S| TTL | 708 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 709 . . 710 . . 711 . . 712 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 713 | Segment(n) | TC |S| TTL | 714 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 715 | Message as shown in Figure 9 | 716 . . 717 +---------------------------------------------------------------+ 719 Figure 10: Example Probe Response Message for SR-MPLS Policy 721 The Path Segment Identifier (PSID) 722 [I-D.ietf-spring-mpls-path-segment] of the forward SR Policy in the 723 probe query can be used to find the associated reverse SR Policy 724 [I-D.ietf-pce-sr-bidir-path] to send the probe response message for 725 two-way measurement of SR Policy unless when using STAMP message with 726 Return Path TLV. 728 4.2.2.2. Probe Response Message for SRv6 Policy 730 The message content for sending probe response message on the 731 congruent path of the data traffic for two-way performance 732 measurement of an end-to-end SRv6 Policy with SRH is shown in 733 Figure 11. The procedure defined for upper-layer header processing 734 for SRv6 SIDs in [I-D.ietf-spring-srv6-network-programming] is used 735 to process the UDP header in the received probe response messages. 737 +---------------------------------------------------------------+ 738 | IP Header | 739 . Source IP Address = Reflector IPv6 Address . 740 . Destination IP Address = Destination IPv6 Address . 741 . . 742 +---------------------------------------------------------------+ 743 | SRH as specified in RFC 8754 | 744 . . 745 . . 746 +---------------------------------------------------------------+ 747 | IP Header (as needed) | 748 . Source IP Address = Reflector IPv6 Address . 749 . Destination IP Address = Source IPv6 Address from Query . 750 . . 751 +---------------------------------------------------------------+ 752 | UDP Header | 753 . Source Port = As chosen by Sender . 754 . Destination Port = User-configured Port . 755 . . 756 +---------------------------------------------------------------+ 757 | Payload = DM Message as specified in Section 4.3 of RFC 8762| | 758 . Payload = LM Message as specified in Figure 12 or 13 . 759 . . 760 +---------------------------------------------------------------+ 762 Figure 11: Example Probe Response Message for SRv6 Policy 764 4.2.3. Loss Measurement Response Message Extensions 766 In this document, STAMP probe response message formats are defined 767 for loss measurement as shown in Figure 12 and Figure 13. 769 0 1 2 3 770 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 1 771 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 772 | Sequence Number | 773 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 774 | Transmit Counter | 775 | | 776 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 777 |X|B| Reserved | Block Number | SSID | 778 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 779 | Receive Counter | 780 | | 781 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 782 | Sender Sequence Number | 783 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 784 | Sender Counter | 785 | | 786 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 787 |X|B| Reserved |Sender Block Nu| MBZ | 788 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 789 | Sender TTL | MBZ | 790 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 792 Figure 12: STAMP LM Probe Response Message - Unauthenticated Mode 794 0 1 2 3 795 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 1 796 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 797 | Sequence Number | 798 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 799 | MBZ (12 octets) | 800 | | 801 | | 802 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 803 | Transmit Counter | 804 | | 805 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 806 |X|B| Reserved | Block Number | SSID | 807 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 808 | MBZ (4 octets) | 809 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 810 | Receive Counter | 811 | | 812 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 813 | MBZ (8 octets) | 814 | | 815 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 816 | Sender Sequence Number | 817 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 818 | MBZ (12 octets) | 819 | | 820 | | 821 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 822 | Sender Counter | 823 | | 824 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 825 |X|B| Reserved |Sender Block Nu| MBZ | 826 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 827 | MBZ (4 octets) | 828 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 829 | Sender TTL | | 830 +-+-+-+-+-+-+-+-+ | 831 | MBZ (15 octets) | 832 | | 833 | | 834 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 835 | | 836 | HMAC (16 octets) | 837 | | 838 | | 839 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 841 Figure 13: STAMP LM Probe Response Message - Authenticated Mode 843 4.3. Node Address TLV Extensions 845 In this document, Node Address TLV is defined for STAMP message 846 [I-D.ietf-ippm-stamp-option-tlv] and has the following format shown 847 in Figure 14: 849 0 1 2 3 850 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 1 851 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 852 |STAMP TLV Flags| Type | Length | 853 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 854 | Reserved | Address Family | 855 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 856 ~ Address ~ 857 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 859 Figure 14: Node Address TLV Format 861 The Address Family field indicates the type of the address, and it 862 SHALL be set to one of the assigned values in the "IANA Address 863 Family Numbers" registry. 865 The STAMP TLV Flags are set using the procedures described in 866 [I-D.ietf-ippm-stamp-option-tlv]. 868 The following Type is defined and it contains Node Address TLV: 870 Destination Node Address (value TBA1): 872 The Destination Node Address TLV is optional. The Destination Node 873 Address TLV indicates the address of the intended recipient node of 874 the probe message. The reflector node MUST NOT send response message 875 if it is not the intended destination node of the probe query 876 message. This check is useful for example, for performance 877 measurement of SR Policy when using the destination address in 127/8 878 range for IPv4 or in ::FFFF:127/104 range for IPv6. 880 4.4. Return Path TLV Extensions 882 For two-way performance measurement, the reflector node needs to send 883 the probe response message on a specific reverse path. The sender 884 node can request in the probe query message to the reflector node to 885 send a response message back on a given reverse path (e.g. co-routed 886 bidirectional path). This way the reflector node does not require 887 any additional SR state for PM (recall that in SR networks, the state 888 is in the probe packet and signaling of the parameters is avoided). 890 For one-way performance measurement, the sender node address may not 891 be reachable via IP route from the reflector node. The sender node 892 in this case needs to send its reachability path information to the 893 reflector node. 895 [I-D.ietf-ippm-stamp-option-tlv] defines STAMP probe query messages 896 that can include one or more optional TLVs. The TLV Type (value 897 TBA2) is defined in this document for Return Path that carries 898 reverse path for STAMP probe response messages (in the payload of the 899 message). The format of the Return Path TLV is shown in Figure 15: 901 0 1 2 3 902 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 1 903 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 904 |STAMP TLV Flags| Type=TBA2 | Length | 905 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 906 | Return Path Sub-TLVs | 907 . . 908 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 910 Figure 15: Return Path TLV 912 The STAMP TLV Flags are set using the procedures described in 913 [I-D.ietf-ippm-stamp-option-tlv]. 915 The following Type defined for the Return Path TLV contains the Node 916 Address sub-TLV using the format shown in Figure 14: 918 o Type (value 0): Return Address. Target node address of the 919 response message different than the Source Address in the query 921 0 1 2 3 922 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 1 923 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 924 |STAMP TLV Flags| Type | Length | 925 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 926 | Segment(1) | 927 . . 928 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 929 . . 930 . . 931 . . 933 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 934 | Segment(n) | 935 . . 936 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 938 Figure 16: Segment List Sub-TLV in Return Path TLV 940 The Segment List Sub-TLV (shown in Figure 16) in the Return Path TLV 941 can be one of the following Types: 943 o Type (value 1): SR-MPLS Label Stack of the Reverse Path 945 o Type (value 2): SR-MPLS Binding SID 946 [I-D.ietf-pce-binding-label-sid] of the Reverse SR Policy 948 o Type (value 3): SRv6 Segment List of the Reverse Path 950 o Type (value 4): SRv6 Binding SID [I-D.ietf-pce-binding-label-sid] 951 of the Reverse SR Policy 953 The Return Path TLV is optional. The sender node MUST only insert 954 one Return Path TLV in the probe query message and the reflector node 955 MUST only process the first Return Path TLV in the probe query 956 message and ignore other Return Path TLVs if present. The reflector 957 node MUST send probe response message back on the reverse path 958 specified in the Return Path TLV and MUST NOT add Return Path TLV in 959 the probe response message. 961 4.5. Additional Probe Message Processing Rules 963 The processing rules defined in this section are applicable to the 964 STAMP messages for delay and loss measurement for Links and end-to- 965 end SR Paths including SR Policies. 967 4.5.1. TTL and Hop Limit 969 The TTL field in the IPv4 and MPLS headers of the probe query 970 messages is set to 255 [RFC8762]. Similarly, the Hop Limit field in 971 the IPv6 and SRH headers of the probe query messages is set to 255 972 [RFC8762]. 974 When using the Destination IPv4 Address from the 127/8 range, the TTL 975 in the IPv4 header is set to 1 [RFC8029]. Similarly, when using the 976 Destination IPv6 Address from the ::FFFF:127/104 range, the Hop Limit 977 field in the IPv6 header is set to 1. 979 For Link performance delay and loss measurements, the TTL or Hop 980 Limit field in the probe message is set to 1 in both one-way and two- 981 way measurement modes. 983 4.5.2. Router Alert Option 985 The Router Alert IP option (RAO) [RFC2113] is not set in the probe 986 messages. 988 4.5.3. UDP Checksum 990 The UDP Checksum Complement for delay and loss measurement messages 991 follows the procedure defined in [RFC7820] and can be optionally used 992 with the procedures defined in this document. 994 For IPv4 and IPv6 probe messages, where the hardware is not capable 995 of re-computing the UDP checksum or adding checksum complement 996 [RFC7820], the sender node sets the UDP checksum to 0 [RFC6936] 997 [RFC8085]. The receiving node bypasses the checksum validation and 998 accepts the packets with UDP checksum value 0 for the UDP port being 999 used for PM delay and loss measurements. 1001 5. Performance Measurement for P2MP SR Policies 1003 The Point-to-Multipoint (P2MP) SR Path that originates from a root 1004 node terminates on multiple destinations called leaf nodes (e.g. 1005 P2MP SR Policy [I-D.ietf-pim-sr-p2mp-policy] or P2MP Transport 1006 [I-D.shen-spring-p2mp-transport-chain]). 1008 The procedures for delay and loss measurement described in this 1009 document for P2P SR Policies are also equally applicable to the P2MP 1010 SR Policies. The procedure for one-way measurement is defined as 1011 following: 1013 o The sender root node sends probe query messages using the Tree-SID 1014 defined in [I-D.ietf-pim-sr-p2mp-policy] for the P2MP SR-MPLS 1015 Policy as shown in Figure 17. 1017 o The probe query messages can contain the replication SID as 1018 defined in [I-D.ietf-spring-sr-replication-segment]. 1020 o Each reflector leaf node sends its IP address in the Source 1021 Address of the probe response messages as shown in Figure 17. 1022 This allows the sender root node to identify the reflector leaf 1023 nodes of the P2MP SR Policy. 1025 o The P2MP root node measures the delay and loss performance for 1026 each P2MP leaf node of the end-to-end P2MP SR Policy. 1028 0 1 2 3 1029 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 1030 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1031 | Tree-SID | TC |S| TTL | 1032 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1033 . . 1034 . . 1035 . . 1036 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1037 | Message as shown in Figure 2 for DM or Figure 3 for LM | 1038 . . 1039 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1041 Figure 17: Example Probe Query with Tree-SID for SR-MPLS Policy 1043 The probe query messages can also be sent using the scheme defined 1044 for P2MP Transport using Chain Replication that may contain Bud SID 1045 as defined in [I-D.shen-spring-p2mp-transport-chain]. 1047 The considerations for two-way mode for performance measurement for 1048 P2MP SR Policy (e.g. for bidirectional SR Path) are outside the scope 1049 of this document. 1051 6. ECMP Support for SR Policies 1053 An SR Policy can have ECMPs between the source and transit nodes, 1054 between transit nodes and between transit and destination nodes. 1055 Usage of Anycast SID [RFC8402] by an SR Policy can result in ECMP 1056 paths via transit nodes part of that Anycast group. The probe 1057 messages need to be sent to traverse different ECMP paths to measure 1058 performance delay of an SR Policy. 1060 Forwarding plane has various hashing functions available to forward 1061 packets on specific ECMP paths. The mechanisms described in 1062 [RFC8029] and [RFC5884] for handling ECMPs are also applicable to the 1063 performance measurement. In IPv4 header of the probe messages, 1064 sweeping of Destination Address in 127/8 range can be used to 1065 exercise particular ECMP paths. As specified in [RFC6437], Flow 1066 Label field in the outer IPv6 header can also be used for sweeping. 1068 The considerations for performance loss measurement for different 1069 ECMP paths of an SR Policy are outside the scope of this document. 1071 7. Performance Delay and Liveness Monitoring 1073 Liveness monitoring is required for connectivity verification and 1074 continuity check in an SR network. The procedure defined in this 1075 document for delay measurement using the STAMP probe messages can 1076 also be applied to liveness monitoring of Links and SR Paths. The 1077 one-way or two-way measurement mode can be used for liveness 1078 monitoring. Liveness failure is notified when consecutive N number 1079 of probe response messages are not received back at the sender node, 1080 where N is locally provisioned value. Note that for one-way and two- 1081 way modes, the failure detection interval and scale for number of 1082 probe messages need to account for the processing of the probe query 1083 messages which need to be punted from the forwarding fast path (to 1084 slow path or control plane) and response messages need to be injected 1085 on the reflector node. This is enhanced by using the probes in 1086 loopback mode as described in [I-D.gandhi-spring-sr-enhanced-plm]. 1088 8. Security Considerations 1090 The performance measurement is intended for deployment in well- 1091 managed private and service provider networks. As such, it assumes 1092 that a node involved in a measurement operation has previously 1093 verified the integrity of the path and the identity of the far-end 1094 reflector node. 1096 If desired, attacks can be mitigated by performing basic validation 1097 and sanity checks, at the sender, of the counter or timestamp fields 1098 in received measurement response messages. The minimal state 1099 associated with these protocols also limits the extent of measurement 1100 disruption that can be caused by a corrupt or invalid message to a 1101 single query/response cycle. 1103 Use of HMAC-SHA-256 in the authenticated mode protects the data 1104 integrity of the probe messages. SRv6 has HMAC protection 1105 authentication defined for SRH [RFC8754]. Hence, probe messages for 1106 SRv6 may not need authentication mode. Cryptographic measures may be 1107 enhanced by the correct configuration of access-control lists and 1108 firewalls. 1110 9. IANA Considerations 1112 IANA will create a "STAMP TLV Type" registry for 1113 [I-D.ietf-ippm-stamp-option-tlv]. IANA is requested to allocate a 1114 value for the following Destination Address TLV Type from the IETF 1115 Review TLV range of this registry. This TLV is to be carried in the 1116 probe messages. 1118 o Type TBA1: Destination Node Address TLV 1120 IANA is also requested to allocate a value for the following Return 1121 Path TLV Type from the IETF Review TLV range of the same registry. 1122 This TLV is to be carried in the probe query messages. 1124 o Type TBA2: Return Path TLV 1126 IANA is requested to create a sub-registry for "Return Path Sub-TLV 1127 Type". All code points in the range 1 through 175 in this registry 1128 shall be allocated according to the "IETF Review" procedure as 1129 specified in [RFC8126]. Code points in the range 176 through 239 in 1130 this registry shall be allocated according to the "First Come First 1131 Served" procedure as specified in [RFC8126]. Remaining code points 1132 are allocated according to Table 1: 1134 +-----------+--------------+---------------+ 1135 | Value | Description | Reference | 1136 +-----------+--------------+---------------+ 1137 | 0 | Reserved | This document | 1138 | 1 - 175 | Unassigned | This document | 1139 | 176 - 239 | Unassigned | This document | 1140 | 240 - 251 | Experimental | This document | 1141 | 252 - 254 | Private Use | This document | 1142 | 255 | Reserved | This document | 1143 +-----------+--------------+---------------+ 1145 Table 1: Return Path Sub-TLV Type Registry 1147 IANA is requested to allocate the values for the following Sub-TLV 1148 Types from this registry. 1150 o Type (value 1): Return Address 1152 o Type (value 2): SR-MPLS Label Stack of the Reverse Path 1153 o Type (value 3): SR-MPLS Binding SID 1154 [I-D.ietf-pce-binding-label-sid] of the Reverse SR Policy 1156 o Type (value 4): SRv6 Segment List of the Reverse Path 1158 o Type (value 5): SRv6 Binding SID [I-D.ietf-pce-binding-label-sid] 1159 of the Reverse SR Policy 1161 10. References 1163 10.1. Normative References 1165 [RFC0768] Postel, J., "User Datagram Protocol", STD 6, RFC 768, 1166 DOI 10.17487/RFC0768, August 1980, 1167 . 1169 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 1170 Requirement Levels", BCP 14, RFC 2119, 1171 DOI 10.17487/RFC2119, March 1997, 1172 . 1174 [RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 1175 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, 1176 May 2017, . 1178 [RFC8762] Mirsky, G., Jun, G., Nydell, H., and R. Foote, "Simple 1179 Two-Way Active Measurement Protocol", RFC 8762, 1180 DOI 10.17487/RFC8762, March 2020, 1181 . 1183 [I-D.ietf-ippm-stamp-option-tlv] 1184 Mirsky, G., Min, X., Nydell, H., Foote, R., Masputra, A., 1185 and E. Ruffini, "Simple Two-way Active Measurement 1186 Protocol Optional Extensions", draft-ietf-ippm-stamp- 1187 option-tlv-08 (work in progress), August 2020. 1189 10.2. Informative References 1191 [IEEE1588] 1192 IEEE, "1588-2008 IEEE Standard for a Precision Clock 1193 Synchronization Protocol for Networked Measurement and 1194 Control Systems", March 2008. 1196 [RFC2104] Krawczyk, H., Bellare, M., and R. Canetti, "HMAC: Keyed- 1197 Hashing for Message Authentication", RFC 2104, 1198 DOI 10.17487/RFC2104, February 1997, 1199 . 1201 [RFC2113] Katz, D., "IP Router Alert Option", RFC 2113, 1202 DOI 10.17487/RFC2113, February 1997, 1203 . 1205 [RFC4868] Kelly, S. and S. Frankel, "Using HMAC-SHA-256, HMAC-SHA- 1206 384, and HMAC-SHA-512 with IPsec", RFC 4868, 1207 DOI 10.17487/RFC4868, May 2007, 1208 . 1210 [RFC5884] Aggarwal, R., Kompella, K., Nadeau, T., and G. Swallow, 1211 "Bidirectional Forwarding Detection (BFD) for MPLS Label 1212 Switched Paths (LSPs)", RFC 5884, DOI 10.17487/RFC5884, 1213 June 2010, . 1215 [RFC6335] Cotton, M., Eggert, L., Touch, J., Westerlund, M., and S. 1216 Cheshire, "Internet Assigned Numbers Authority (IANA) 1217 Procedures for the Management of the Service Name and 1218 Transport Protocol Port Number Registry", BCP 165, 1219 RFC 6335, DOI 10.17487/RFC6335, August 2011, 1220 . 1222 [RFC6437] Amante, S., Carpenter, B., Jiang, S., and J. Rajahalme, 1223 "IPv6 Flow Label Specification", RFC 6437, 1224 DOI 10.17487/RFC6437, November 2011, 1225 . 1227 [RFC6936] Fairhurst, G. and M. Westerlund, "Applicability Statement 1228 for the Use of IPv6 UDP Datagrams with Zero Checksums", 1229 RFC 6936, DOI 10.17487/RFC6936, April 2013, 1230 . 1232 [RFC7820] Mizrahi, T., "UDP Checksum Complement in the One-Way 1233 Active Measurement Protocol (OWAMP) and Two-Way Active 1234 Measurement Protocol (TWAMP)", RFC 7820, 1235 DOI 10.17487/RFC7820, March 2016, 1236 . 1238 [RFC8029] Kompella, K., Swallow, G., Pignataro, C., Ed., Kumar, N., 1239 Aldrin, S., and M. Chen, "Detecting Multiprotocol Label 1240 Switched (MPLS) Data-Plane Failures", RFC 8029, 1241 DOI 10.17487/RFC8029, March 2017, 1242 . 1244 [RFC8085] Eggert, L., Fairhurst, G., and G. Shepherd, "UDP Usage 1245 Guidelines", BCP 145, RFC 8085, DOI 10.17487/RFC8085, 1246 March 2017, . 1248 [RFC8126] Cotton, M., Leiba, B., and T. Narten, "Guidelines for 1249 Writing an IANA Considerations Section in RFCs", BCP 26, 1250 RFC 8126, DOI 10.17487/RFC8126, June 2017, 1251 . 1253 [RFC8186] Mirsky, G. and I. Meilik, "Support of the IEEE 1588 1254 Timestamp Format in a Two-Way Active Measurement Protocol 1255 (TWAMP)", RFC 8186, DOI 10.17487/RFC8186, June 2017, 1256 . 1258 [RFC8321] Fioccola, G., Ed., Capello, A., Cociglio, M., Castaldelli, 1259 L., Chen, M., Zheng, L., Mirsky, G., and T. Mizrahi, 1260 "Alternate-Marking Method for Passive and Hybrid 1261 Performance Monitoring", RFC 8321, DOI 10.17487/RFC8321, 1262 January 2018, . 1264 [RFC8402] Filsfils, C., Ed., Previdi, S., Ed., Ginsberg, L., 1265 Decraene, B., Litkowski, S., and R. Shakir, "Segment 1266 Routing Architecture", RFC 8402, DOI 10.17487/RFC8402, 1267 July 2018, . 1269 [RFC8754] Filsfils, C., Ed., Dukes, D., Ed., Previdi, S., Leddy, J., 1270 Matsushima, S., and D. Voyer, "IPv6 Segment Routing Header 1271 (SRH)", RFC 8754, DOI 10.17487/RFC8754, March 2020, 1272 . 1274 [I-D.ietf-spring-segment-routing-policy] 1275 Filsfils, C., Talaulikar, K., Voyer, D., Bogdanov, A., and 1276 P. Mattes, "Segment Routing Policy Architecture", draft- 1277 ietf-spring-segment-routing-policy-08 (work in progress), 1278 July 2020. 1280 [I-D.ietf-spring-sr-replication-segment] 1281 Voyer, D., Filsfils, C., Parekh, R., Bidgoli, H., and Z. 1282 Zhang, "SR Replication Segment for Multi-point Service 1283 Delivery", draft-ietf-spring-sr-replication-segment-00 1284 (work in progress), July 2020. 1286 [I-D.shen-spring-p2mp-transport-chain] 1287 Shen, Y., Zhang, Z., Parekh, R., Bidgoli, H., and Y. 1288 Kamite, "Point-to-Multipoint Transport Using Chain 1289 Replication in Segment Routing", draft-shen-spring-p2mp- 1290 transport-chain-02 (work in progress), April 2020. 1292 [I-D.ietf-pim-sr-p2mp-policy] 1293 Voyer, D., Filsfils, C., Parekh, R., Bidgoli, H., and Z. 1294 Zhang, "Segment Routing Point-to-Multipoint Policy", 1295 draft-ietf-pim-sr-p2mp-policy-00 (work in progress), July 1296 2020. 1298 [I-D.ietf-spring-mpls-path-segment] 1299 Cheng, W., Li, H., Chen, M., Gandhi, R., and R. Zigler, 1300 "Path Segment in MPLS Based Segment Routing Network", 1301 draft-ietf-spring-mpls-path-segment-02 (work in progress), 1302 February 2020. 1304 [I-D.ietf-spring-srv6-network-programming] 1305 Filsfils, C., Camarillo, P., Leddy, J., Voyer, D., 1306 Matsushima, S., and Z. Li, "SRv6 Network Programming", 1307 draft-ietf-spring-srv6-network-programming-16 (work in 1308 progress), June 2020. 1310 [I-D.ietf-pce-binding-label-sid] 1311 Filsfils, C., Sivabalan, S., Tantsura, J., Hardwick, J., 1312 Previdi, S., and C. Li, "Carrying Binding Label/Segment-ID 1313 in PCE-based Networks.", draft-ietf-pce-binding-label- 1314 sid-03 (work in progress), June 2020. 1316 [I-D.gandhi-mpls-ioam-sr] 1317 Gandhi, R., Ali, Z., Filsfils, C., Brockners, F., Wen, B., 1318 and V. Kozak, "MPLS Data Plane Encapsulation for In-situ 1319 OAM Data", draft-gandhi-mpls-ioam-sr-02 (work in 1320 progress), March 2020. 1322 [I-D.ali-spring-ioam-srv6] 1323 Ali, Z., Gandhi, R., Filsfils, C., Brockners, F., Kumar, 1324 N., Pignataro, C., Li, C., Chen, M., and G. Dawra, 1325 "Segment Routing Header encapsulation for In-situ OAM 1326 Data", draft-ali-spring-ioam-srv6-02 (work in progress), 1327 November 2019. 1329 [I-D.ietf-pce-sr-bidir-path] 1330 Li, C., Chen, M., Cheng, W., Gandhi, R., and Q. Xiong, 1331 "PCEP Extensions for Associated Bidirectional Segment 1332 Routing (SR) Paths", draft-ietf-pce-sr-bidir-path-02 (work 1333 in progress), March 2020. 1335 [I-D.gandhi-spring-sr-enhanced-plm] 1336 Gandhi, R., Filsfils, C., Vaghamshi, N., Nagarajah, M., 1337 and R. Foote, "Enhanced Performance Delay and Liveness 1338 Monitoring in Segment Routing Networks", draft-gandhi- 1339 spring-sr-enhanced-plm-02 (work in progress), July 2020. 1341 Acknowledgments 1343 The authors would like to thank Thierry Couture for the discussions 1344 on the use-cases for Performance Measurement in Segment Routing. The 1345 authors would also like to thank Greg Mirsky for reviewing this 1346 document and providing useful comments and suggestions. Patrick 1347 Khordoc and Radu Valceanu, both from Cisco Systems have helped 1348 significantly improve the mechanisms defined in this document. The 1349 authors would like to acknowledge the earlier work on the loss 1350 measurement using TWAMP described in draft-xiao-ippm-twamp-ext- 1351 direct-loss. The authors would also like to thank Sam Aldrin for the 1352 discussions to check for broken path. 1354 Authors' Addresses 1356 Rakesh Gandhi (editor) 1357 Cisco Systems, Inc. 1358 Canada 1360 Email: rgandhi@cisco.com 1362 Clarence Filsfils 1363 Cisco Systems, Inc. 1365 Email: cfilsfil@cisco.com 1367 Daniel Voyer 1368 Bell Canada 1370 Email: daniel.voyer@bell.ca 1372 Mach(Guoyi) Chen 1373 Huawei 1375 Email: mach.chen@huawei.com 1377 Bart Janssens 1378 Colt 1380 Email: Bart.Janssens@colt.net