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Checking references for intended status: Proposed Standard ---------------------------------------------------------------------------- (See RFCs 3967 and 4897 for information about using normative references to lower-maturity documents in RFCs) == Outdated reference: A later version (-04) exists of draft-ietf-ippm-port-twamp-test-00 -- Possible downref: Non-RFC (?) normative reference: ref. 'IEEE.1588.2008' Summary: 0 errors (**), 0 flaws (~~), 2 warnings (==), 2 comments (--). Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 2 Network Working Group G. Mirsky 3 Internet-Draft ZTE Corp. 4 Intended status: Standards Track G. Jun 5 Expires: September 2, 2018 ZTE Corporation 6 H. Nydell 7 Accedian Networks 8 R. Foote 9 Nokia 10 March 1, 2018 12 Simple Two-way Active Measurement Protocol 13 draft-ietf-ippm-stamp-01 15 Abstract 17 This document describes a Simple Two-way Active Measurement Protocol 18 which enables measurement of both one-way and round-trip performance 19 metrics like delay, delay variation and packet loss. 21 Status of This Memo 23 This Internet-Draft is submitted in full conformance with the 24 provisions of BCP 78 and BCP 79. 26 Internet-Drafts are working documents of the Internet Engineering 27 Task Force (IETF). Note that other groups may also distribute 28 working documents as Internet-Drafts. The list of current Internet- 29 Drafts is at https://datatracker.ietf.org/drafts/current/. 31 Internet-Drafts are draft documents valid for a maximum of six months 32 and may be updated, replaced, or obsoleted by other documents at any 33 time. It is inappropriate to use Internet-Drafts as reference 34 material or to cite them other than as "work in progress." 36 This Internet-Draft will expire on September 2, 2018. 38 Copyright Notice 40 Copyright (c) 2018 IETF Trust and the persons identified as the 41 document authors. All rights reserved. 43 This document is subject to BCP 78 and the IETF Trust's Legal 44 Provisions Relating to IETF Documents 45 (https://trustee.ietf.org/license-info) in effect on the date of 46 publication of this document. Please review these documents 47 carefully, as they describe your rights and restrictions with respect 48 to this document. Code Components extracted from this document must 49 include Simplified BSD License text as described in Section 4.e of 50 the Trust Legal Provisions and are provided without warranty as 51 described in the Simplified BSD License. 53 Table of Contents 55 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 56 2. Conventions used in this document . . . . . . . . . . . . . . 3 57 2.1. Terminology . . . . . . . . . . . . . . . . . . . . . . . 3 58 2.2. Requirements Language . . . . . . . . . . . . . . . . . . 3 59 3. Softwarization of Performance Measurement . . . . . . . . . . 3 60 4. Theory of Operation . . . . . . . . . . . . . . . . . . . . . 4 61 4.1. Session-Sender Behavior and Packet Format . . . . . . . . 4 62 4.1.1. Session-Sender Packet Format in Unauthenticated Mode 4 63 4.1.2. Session-Sender Packet Format in Authenticated and 64 Encrypted Modes . . . . . . . . . . . . . . . . . . . 7 65 4.2. Session-Reflector Behavior and Packet Format . . . . . . 8 66 4.2.1. Session-Reflector Packet Format in Unauthenticated 67 Mode . . . . . . . . . . . . . . . . . . . . . . . . 9 68 4.2.2. Session-Reflector Packet Format in Authenticated and 69 Encrypted Modes . . . . . . . . . . . . . . . . . . . 10 70 4.3. Interoperability with TWAMP Light . . . . . . . . . . . . 12 71 5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 12 72 6. Security Considerations . . . . . . . . . . . . . . . . . . . 12 73 7. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 12 74 8. References . . . . . . . . . . . . . . . . . . . . . . . . . 13 75 8.1. Normative References . . . . . . . . . . . . . . . . . . 13 76 8.2. Informative References . . . . . . . . . . . . . . . . . 14 77 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 14 79 1. Introduction 81 Development and deployment of Two-Way Active Measurement Protocol 82 (TWAMP) [RFC5357] and its extensions, e.g. [RFC6038] that defined 83 features such as Reflect Octets and Symmetrical Size for TWAMP, 84 provided invaluable experience. Several independent implementations 85 exist, have been deployed and provide important operational 86 performance measurements. At the same time there has been noticeable 87 interest in using a simpler mechanism for active performance 88 monitoring that can provide deterministic behaviour and inherit 89 separation of control (vendor-specific configuration or 90 orchestration) and test functions. One of such is Performance 91 Measurement from IP Edge to Customer Equipment using TWAMP Light from 92 Broadband Forum ([BBF.TR-390]). This document defines active 93 performance measurement test protocol, Simple Two-way Active 94 Measurement Protocol (STAMP), that enables measurement of both one- 95 way and round-trip performance metrics like delay, delay variation 96 and packet loss. 98 2. Conventions used in this document 100 2.1. Terminology 102 STAMP - Simple Two-way Active Measurement Protocol 104 NTP - Network Time Protocol 106 PTP - Precision Time Protocol 108 HMAC Hashed Message Authentication Code 110 OWAMP One-Way Active Measurement Protocol 112 TWAMP Two-Way Active Measurement Protocol 114 2.2. Requirements Language 116 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 117 "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and 118 "OPTIONAL" in this document are to be interpreted as described in BCP 119 14 [RFC2119] [RFC8174] when, and only when, they appear in all 120 capitals, as shown here. 122 3. Softwarization of Performance Measurement 124 Figure 1 presents Simple Two-way Active Measurement Protocol (STAMP) 125 Session-Sender and Session-Reflector with a measurement session. The 126 configuration and management of the STAMP Session-Sender, Session- 127 Reflector and management of the STAMP sessions can be achieved 128 through various means. Command Line Interface, OSS/BSS using SNMP or 129 SDN using Netconf/YANG are but a few examples. 131 o----------------------------------------------------------o 132 | Configuration and | 133 | Management | 134 o----------------------------------------------------------o 135 || || 136 || || 137 || || 138 +----------------------+ +-------------------------+ 139 | STAMP Session-Sender | <--- STAMP---> | STAMP Session-Reflector | 140 +----------------------+ +-------------------------+ 142 Figure 1: STAMP Reference Model 144 4. Theory of Operation 146 STAMP Session-Sender transmits test packets toward STAMP Session- 147 Reflector. STAMP Session-Reflector receives Session-Sender's packet 148 and acts according to the configuration and optional control 149 information communicated in the Session-Sender's test packet. STAMP 150 defines two different test packet formats, one for packets 151 transmitted by the STAMP-Session-Sender and one for packets 152 transmitted by the STAMP-Session-Reflector. STAMP supports three 153 modes: unauthenticated, authenticated, and encrypted. 154 Unauthenticated STAMP test packets are compatible on the wire with 155 unauthenticated TWAMP-Test [RFC5357] packet formats. 157 By default STAMP uses symmetrical packets, i.e. size of the packet 158 transmitted by Session-Reflector equals to the size of the packet 159 received by the Session-Reflector. 161 4.1. Session-Sender Behavior and Packet Format 163 4.1.1. Session-Sender Packet Format in Unauthenticated Mode 165 Because STAMP supports symmetrical test packets, STAMP Session-Sender 166 packet has minimum size of 44 octets in unauthenticated mode, see 167 Figure 2, and 48 octets in authenticated or encrypted modes , see 168 Figure 4. 170 For unauthenticated mode: 172 0 1 2 3 173 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 1 174 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 175 | Sequence Number | 176 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 177 | Timestamp | 178 | | 179 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 180 | Error Estimate | | 181 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + 182 | | 183 | | 184 | MBZ (27 octets) | 185 | | 186 | | 187 | | 188 + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 189 | | Server Octets | | 190 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + 191 | Remaining Packet Padding (to be reflected) | 192 ~ (length in octets specified in Server Octets) ~ 193 + +-+-+-+-+-+-+-+-+ 194 | | Comp.MBZ | 195 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 196 | Type | Length | 197 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 198 ~ Value ~ 199 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 201 Figure 2: STAMP Session-Sender test packet format in unauthenticated 202 mode 204 where fields are defined as the following: 206 o Sequence Number is four octets long field. For each new session 207 its value starts at zero and is incremented with each transmitted 208 packet. 210 o Timestamp is eight octets long field. STAMP node MUST support 211 Network Time Protocol (NTP) version 4 64-bit timestamp format 212 [RFC5905]. STAMP node MAY support IEEE 1588v2 Precision Time 213 Protocol truncated 64-bit timestamp format [IEEE.1588.2008]. 215 o Error Estimate is two octets long field with format displayed in 216 Figure 3 217 0 1 218 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 219 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 220 |S|Z| Scale | Multiplier | 221 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 223 Figure 3: Error Estimate Format 225 where S, Scale and Multiplier fields are interpreted as they have 226 been defined in section 4.1.2 [RFC4656]; and Z field - as has been 227 defined in section 2.3 [RFC8186]: 229 * 0 - NTP 64 bit format of a timestamp; 231 * 1 - PTPv2 truncated format of a timestamp. 233 The STAMP Session-Sender and Session-Reflector MAY use, not use, 234 or set value of the Z field in accordance with the timestamp 235 format in use. This optional field is to enhance operations but 236 local configuration or defaults could be used in its place. 238 o Must-be-Zero (MBZ) field in the session-sender unauthenticated 239 packet is 27 octets long. It MUST be all zeroed on transmission 240 and ignored on receipt. 242 o Server Octets field is two octets long field. It MUST follow the 243 27 octets long MBZ field. The Reflect Octets capability defined 244 in [RFC6038]. The value in the Server Octets field equals to the 245 number of octets the Session-Reflector is expected to copy back to 246 the Session-Sender starting with the Server Octets field. Thus 247 the minimal non-zero value for the Server Octets field is two and 248 value of one is invalid. If none of Payload to be copied the 249 value of the Server Octets field MUST be set to zero on transmit. 251 o Remaining Packet Padding is optional field of variable length. 252 The number of octets in the Remaining Packet Padding field is the 253 value of the Server Octets field less the length of the Server 254 Octets field. 256 o Comp.MBZ is variable length field used to achieve alignment on 257 word boundary. Thus the length of Comp.MBZ field may be only 0, 258 1, 2 or 3 octets. The value of the field MUST be zeroed on 259 transmission and ignored on receipt. 261 The unauthenticated STAMP Session-Sender packet MAY include Type- 262 Length-Value encodings that immediately follow the Comp. MBZ field. 264 o Type field is two octets long. The value of the Type field is the 265 codepoint allocated by IANA Section 5 that identifies data in the 266 Value field. 268 o Length is two octets long field and its value is the length of the 269 Value field in octets. 271 o Value field contains the application specific information. The 272 length of the Value field MUST be four octets aligned. 274 4.1.2. Session-Sender Packet Format in Authenticated and Encrypted 275 Modes 277 For authenticated and encrypted modes: 279 0 1 2 3 280 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 1 281 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 282 | Sequence Number | 283 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 284 | | 285 | MBZ (12 octets) | 286 | | 287 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 288 | Timestamp | 289 | | 290 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 291 | Error Estimate | | 292 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + 293 ~ ~ 294 | MBZ (70 octets) | 295 ~ ~ 296 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 297 | Type | Length | 298 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 299 ~ Value ~ 300 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 301 ~ Comp.MBZ ~ 302 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 303 | | 304 | HMAC (16 octets) | 305 | | 306 | | 307 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 309 Figure 4: STAMP Session-Sender test packet format in authenticated or 310 encrypted modes 312 The field definitions are the same as the unauthenticated mode, 313 listed in Section 4.1.1. In addition, Commp.MBZ field is variable 314 length filed to align the packet on 16 octets boundary. Also, the 315 packet includes a key-hashed message authentication code (HMAC) 316 ([RFC2104]) hash at the end of the PDU. 318 The STAMP Session-Sender-packet format (Figure 4) is the same in 319 authenticated and encrypted modes. The encryption and authentication 320 operations are, however, different and protect the data as following: 322 in authenticated mode the Sequence Number is protected while the 323 Timestamp and the Error Estimate are sent in clear text; 325 in encrypted mode all fields, including the timestamp and Error 326 Estimate, are protected to provide maximum data confidentiality 327 and integrity protection. 329 Sending the Timestamp in clear text in authenticated mode allows more 330 consistent reading of time by a Session-Sender on the transmission of 331 the test packet. Reading of the time in encrypted mode must be 332 followed by its encryption which introduces variable delay thus 333 affecting calculated timing metrics. 335 4.2. Session-Reflector Behavior and Packet Format 337 The Session-Reflector receives the STAMP test packet, verifies it, 338 prepares and transmits the reflected test packet. 340 Two modes of STAMP Session-Reflector characterize expected behavior 341 and, consequently, performance metrics that can be measured: 343 o Stateless - STAMP Session-Reflector does not maintain test state 344 and will reflect back the received sequence number without 345 modification. As a result, only round-trip packet loss can be 346 calculated while the reflector is operating in stateless mode. 348 o Stateful - STAMP Session-Reflector maintains test state 349 determining forward loss, gaps recognized in the received sequence 350 number. This means both near-end (forward) and far-end (backward) 351 packet loss can be computed. This implies that the STAMP Session- 352 Reflector MUST keep a state for each accepted STAMP-test session, 353 uniquely identifying STAMP-test packets to one such session 354 instance, and enabling adding a sequence number in the test reply 355 that is individually incremented on a per-session basis. 357 4.2.1. Session-Reflector Packet Format in Unauthenticated Mode 359 For unauthenticated mode: 361 0 1 2 3 362 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 1 363 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 364 | Sequence Number | 365 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 366 | Timestamp | 367 | | 368 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 369 | Error Estimate | MBZ | 370 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 371 | Receive Timestamp | 372 | | 373 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 374 | Session-Sender Sequence Number | 375 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 376 | Session-Sender Timestamp | 377 | | 378 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 379 | Session-Sender Error Estimate | MBZ | 380 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 381 |Ses-Sender TTL | | 382 +-+-+-+-+-+-+-+-+ + 383 | | 384 ~ Packet Padding (reflected) ~ 385 + +-+-+-+-+-+-+-+-+ 386 | | Comp.MBZ | 387 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 388 | Type | Length | 389 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 390 ~ Value ~ 391 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 393 Figure 5: STAMP Session-Reflector test packet format in 394 unauthenticated mode 396 where fields are defined as the following: 398 o Sequence Number is four octets long field. The value of the 399 Sequence Number field is set according to the mode of the STAMP 400 Session-Reflector: 402 * in the stateless mode the Session-Reflector copies the value 403 from the received STAMP test packet's Sequence Number field; 405 * in the stateful mode the Session-Reflector counts the received 406 STAMP test packets in each test session and uses that counter 407 to set value of the Sequence Number field. 409 o Timestamp and Receiver Timestamp fields are each 8 octets long. 410 The format of these fields, NTP or PTPv2, indicated by the Z flag 411 of the Error Estimate field as described in Section 4.1. 413 o Error Estimate has the same size and interpretation as described 414 in Section 4.1. 416 o Session-Sender Sequence Number, Session-Sender Timestamp, and 417 Session-Sender Error Estimate are copies of the corresponding 418 fields in the STAMP test packet send by the Session-Sender. 420 o Ses(sion)-Sender TTL is one octet long field and its value is the 421 copy of the TTL field from the received STAMP test packet. 423 o Packet Padding (reflected) is optional variable length field. The 424 length of the Packet Padding (reflected) field MUST be equal to 425 the value of the Server Octets field (Figure 2). If the value is 426 non-zero, the Session-Reflector copies octets starting with the 427 Server Octets field. 429 o Comp.MBZ is variable length field used to achieve alignment on 430 word boundary. Thus the length of Comp.MBZ field may be only 0, 431 1, 2 or 3 octets. The value of the field MUST be zeroed on 432 transmission and ignored on receipt. 434 4.2.2. Session-Reflector Packet Format in Authenticated and Encrypted 435 Modes 437 For authenticated and encrypted modes: 439 0 1 2 3 440 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 1 441 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 442 | Sequence Number | 443 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 444 | MBZ (12 octets) | 445 | | 446 | | 447 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 448 | Timestamp | 449 | | 450 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 451 | Error Estimate | | 452 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + 453 | MBZ (6 octets) | 454 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 455 | Receive Timestamp | 456 | | 457 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 458 | MBZ (8 octets) | 459 | | 460 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 461 | Session-Sender Sequence Number | 462 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 463 | MBZ (12 octets) | 464 | | 465 | | 466 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 467 | Session-Sender Timestamp | 468 | | 469 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 470 | Session-Sender Error Estimate | | 471 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + 472 | MBZ (6 octets) | 473 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 474 |Ses-Sender TTL | | 475 +-+-+-+-+-+-+-+-+ + 476 | | 477 | MBZ (15 octets) | 478 | | 479 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 480 | Type | Length | 481 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 482 ~ Value ~ 483 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 484 ~ Comp.MBZ ~ 485 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 486 | HMAC (16 octets) | 487 | | 488 | | 489 | | 490 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 492 Figure 6: STAMP Session-Reflector test packet format in authenticated 493 or encrypted modes 495 The field definitions are the same as the unauthenticated mode, 496 listed in Section 4.2.1, and includes a key-hashed message 497 authentication code (HMAC) ([RFC2104]) hash at the end of the PDU. 499 4.3. Interoperability with TWAMP Light 501 One of important requirements to STAMP is ability to interwork with 502 TWAMP Light device. There are two possible combinations for such use 503 case: 505 o STAMP Session-Sender with TWAMP Light Session-Reflector; 507 o TWAMP Light Session-Sender with STAMP Session-Reflector. 509 In the former case, Session-Sender MAY not be aware that its Session- 510 Reflector does not support STAMP. For example, TWAMP Light Session- 511 Reflector may not support use of UDP port 862 as defined in 512 [I-D.ietf-ippm-port-twamp-test]. But because STAMP Session-Sender 513 MUST be able to send test packets to destination UDP port number from 514 the Dynamic and/or Private Ports range 49152-65535, test management 515 system should find port number that both devices can use. And if any 516 of TLV-based STAMP extensions are used, the TWAMP Light Session- 517 Reflector will view them as Packet Padding field. The Session-Sender 518 SHOULD use the default format for its timestamps - NTP. And it MAY 519 use PTPv2 timestamp format. 521 In the latter scenario, test management system should set STAMP 522 Session-Reflector to use UDP port number from the Dynamic and/or 523 Private Ports range. As for Packet Padding field that the TWAMP 524 Light Session-Sender includes in its transmitted packet, the STAMP 525 Session-Reflector will process it according to [RFC6038] and return 526 reflected packet of the symmetrical size. The Session-Reflector MUST 527 use the default format for its timestamps - NTP. 529 5. IANA Considerations 531 This document doesn't have any IANA action. This section may be 532 removed before the publication. 534 6. Security Considerations 536 Use of HMAC in authenticated and encrypted modes may be used to 537 simultaneously verify both the data integrity and the authentication 538 of the STAMP test packets. 540 7. Acknowledgments 542 TBD 544 8. References 546 8.1. Normative References 548 [BBF.TR-390] 549 "Performance Measurement from IP Edge to Customer 550 Equipment using TWAMP Light", BBF TR-390, May 2017. 552 [I-D.ietf-ippm-port-twamp-test] 553 Morton, A. and G. Mirsky, "OWAMP and TWAMP Well-Known Port 554 Assignments", draft-ietf-ippm-port-twamp-test-00 (work in 555 progress), January 2018. 557 [IEEE.1588.2008] 558 "Standard for a Precision Clock Synchronization Protocol 559 for Networked Measurement and Control Systems", 560 IEEE Standard 1588, March 2008. 562 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 563 Requirement Levels", BCP 14, RFC 2119, 564 DOI 10.17487/RFC2119, March 1997, 565 . 567 [RFC4656] Shalunov, S., Teitelbaum, B., Karp, A., Boote, J., and M. 568 Zekauskas, "A One-way Active Measurement Protocol 569 (OWAMP)", RFC 4656, DOI 10.17487/RFC4656, September 2006, 570 . 572 [RFC5357] Hedayat, K., Krzanowski, R., Morton, A., Yum, K., and J. 573 Babiarz, "A Two-Way Active Measurement Protocol (TWAMP)", 574 RFC 5357, DOI 10.17487/RFC5357, October 2008, 575 . 577 [RFC5905] Mills, D., Martin, J., Ed., Burbank, J., and W. Kasch, 578 "Network Time Protocol Version 4: Protocol and Algorithms 579 Specification", RFC 5905, DOI 10.17487/RFC5905, June 2010, 580 . 582 [RFC6038] Morton, A. and L. Ciavattone, "Two-Way Active Measurement 583 Protocol (TWAMP) Reflect Octets and Symmetrical Size 584 Features", RFC 6038, DOI 10.17487/RFC6038, October 2010, 585 . 587 [RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 588 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, 589 May 2017, . 591 [RFC8186] Mirsky, G. and I. Meilik, "Support of the IEEE 1588 592 Timestamp Format in a Two-Way Active Measurement Protocol 593 (TWAMP)", RFC 8186, DOI 10.17487/RFC8186, June 2017, 594 . 596 8.2. Informative References 598 [RFC2104] Krawczyk, H., Bellare, M., and R. Canetti, "HMAC: Keyed- 599 Hashing for Message Authentication", RFC 2104, 600 DOI 10.17487/RFC2104, February 1997, 601 . 603 Authors' Addresses 605 Greg Mirsky 606 ZTE Corp. 608 Email: gregimirsky@gmail.com 610 Guo Jun 611 ZTE Corporation 612 68# Zijinghua Road 613 Nanjing, Jiangsu 210012 614 P.R.China 616 Phone: +86 18105183663 617 Email: guo.jun2@zte.com.cn 619 Henrik Nydell 620 Accedian Networks 622 Email: hnydell@accedian.com 624 Richard Foote 625 Nokia 627 Email: footer.foote@nokia.com