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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) No issues found here. Summary: 0 errors (**), 0 flaws (~~), 1 warning (==), 1 comment (--). Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 2 Network Working Group G. Mirsky 3 Internet-Draft X. Min 4 Updates: 8762 (if approved) ZTE Corp. 5 Intended status: Standards Track H. Nydell 6 Expires: September 23, 2020 Accedian Networks 7 R. Foote 8 Nokia 9 A. Masputra 10 Apple Inc. 11 E. Ruffini 12 OutSys 13 March 22, 2020 15 Simple Two-way Active Measurement Protocol Optional Extensions 16 draft-ietf-ippm-stamp-option-tlv-04 18 Abstract 20 This document describes optional extensions to Simple Two-way Active 21 Measurement Protocol (STAMP) which enable measurement performance 22 metrics in addition to ones supported by the STAMP base 23 specification. The document also defines a STAMP Test Session 24 Identifier and thus updates RFC 8762. 26 Status of This Memo 28 This Internet-Draft is submitted in full conformance with the 29 provisions of BCP 78 and BCP 79. 31 Internet-Drafts are working documents of the Internet Engineering 32 Task Force (IETF). Note that other groups may also distribute 33 working documents as Internet-Drafts. The list of current Internet- 34 Drafts is at https://datatracker.ietf.org/drafts/current/. 36 Internet-Drafts are draft documents valid for a maximum of six months 37 and may be updated, replaced, or obsoleted by other documents at any 38 time. It is inappropriate to use Internet-Drafts as reference 39 material or to cite them other than as "work in progress." 41 This Internet-Draft will expire on September 23, 2020. 43 Copyright Notice 45 Copyright (c) 2020 IETF Trust and the persons identified as the 46 document authors. All rights reserved. 48 This document is subject to BCP 78 and the IETF Trust's Legal 49 Provisions Relating to IETF Documents 50 (https://trustee.ietf.org/license-info) in effect on the date of 51 publication of this document. Please review these documents 52 carefully, as they describe your rights and restrictions with respect 53 to this document. Code Components extracted from this document must 54 include Simplified BSD License text as described in Section 4.e of 55 the Trust Legal Provisions and are provided without warranty as 56 described in the Simplified BSD License. 58 Table of Contents 60 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 61 2. Conventions used in this document . . . . . . . . . . . . . . 3 62 2.1. Terminology . . . . . . . . . . . . . . . . . . . . . . . 3 63 2.2. Requirements Language . . . . . . . . . . . . . . . . . . 3 64 3. STAMP Test Session Identifier . . . . . . . . . . . . . . . . 4 65 4. TLV Extensions to STAMP . . . . . . . . . . . . . . . . . . . 8 66 4.1. Extra Padding TLV . . . . . . . . . . . . . . . . . . . . 9 67 4.2. Location TLV . . . . . . . . . . . . . . . . . . . . . . 10 68 4.3. Timestamp Information TLV . . . . . . . . . . . . . . . . 11 69 4.4. Class of Service TLV . . . . . . . . . . . . . . . . . . 12 70 4.5. Direct Measurement TLV . . . . . . . . . . . . . . . . . 14 71 4.6. Access Report TLV . . . . . . . . . . . . . . . . . . . . 14 72 4.7. Follow-up Telemetry TLV . . . . . . . . . . . . . . . . . 16 73 4.8. HMAC TLV . . . . . . . . . . . . . . . . . . . . . . . . 17 74 5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 19 75 5.1. STAMP TLV Registry . . . . . . . . . . . . . . . . . . . 19 76 5.2. Synchronization Source Sub-registry . . . . . . . . . . . 20 77 5.3. Timestamping Method Sub-registry . . . . . . . . . . . . 20 78 5.4. Access ID Sub-registry . . . . . . . . . . . . . . . . . 21 79 5.5. Return Code Sub-registry . . . . . . . . . . . . . . . . 22 80 6. Security Considerations . . . . . . . . . . . . . . . . . . . 23 81 7. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 23 82 8. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 23 83 9. References . . . . . . . . . . . . . . . . . . . . . . . . . 23 84 9.1. Normative References . . . . . . . . . . . . . . . . . . 23 85 9.2. Informative References . . . . . . . . . . . . . . . . . 24 86 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 24 88 1. Introduction 90 Simple Two-way Active Measurement Protocol (STAMP) [RFC8762] supports 91 the use of optional extensions that use Type-Length-Value (TLV) 92 encoding. Such extensions are to enhance the STAMP base functions, 93 such as measurement of one-way and round-trip delay, latency, packet 94 loss, as well as ability to detect packet duplication and out-of- 95 order delivery of the test packets. This specification provides 96 definitions of optional STAMP extensions, their formats, and theory 97 of operation. Also, a STAMP Test Session Identifier is defined for 98 as an update of the base STAMP specification [RFC8762]. 100 2. Conventions used in this document 102 2.1. Terminology 104 STAMP - Simple Two-way Active Measurement Protocol 106 DSCP - Differentiated Services Code Point 108 ECN - Explicit Congestion Notification 110 NTP - Network Time Protocol 112 PTP - Precision Time Protocol 114 HMAC Hashed Message Authentication Code 116 TLV Type-Length-Value 118 BITS Building Integrated Timing Supply 120 SSU Synchronization Supply Unit 122 GPS Global Positioning System 124 GLONASS Global Orbiting Navigation Satellite System 126 LORAN-C Long Range Navigation System Version C 128 MBZ Must Be Zeroed 130 CoS Class of Service 132 PMF Performance Measurement Function 134 SSID STAMP Session Identifier 136 2.2. Requirements Language 138 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 139 "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and 140 "OPTIONAL" in this document are to be interpreted as described in BCP 141 14 [RFC2119] [RFC8174] when, and only when, they appear in all 142 capitals, as shown here. 144 3. STAMP Test Session Identifier 146 STAMP Session-Sender transmits test packets to 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 two 153 modes: unauthenticated and authenticated. Unauthenticated STAMP test 154 packets are compatible on the wire with unauthenticated TWAMP-Test 155 [RFC5357] packet formats. 157 By default, STAMP uses symmetrical packets, i.e., the size of the 158 packet transmitted by Session-Reflector equals the size of the packet 159 received by the Session-Reflector. 161 A STAMP Session is identified using 4-tuple (source and destination 162 IP addresses, source and destination UDP port numbers). A STAMP 163 Session-Sender MAY generate locally unique STAMP Session Identifier 164 (SSID). SSID is two octets long non-zero unsigned integer. A 165 Session-Sender MAY use SSID to identify a STAMP test session. If 166 SSID is used, it MUST be present in each test packet of the given 167 test session. In the unauthenticated mode, SSID is located, as 168 displayed in Figure 1. 170 0 1 2 3 171 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 1 172 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 173 | Sequence Number | 174 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 175 | Timestamp | 176 | | 177 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 178 | Error Estimate | SSID | 179 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 180 | | 181 | | 182 | MBZ (28 octets) | 183 | | 184 | | 185 | | 186 | | 187 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 188 | Type | Length | 189 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 190 ~ Value ~ 191 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 193 Figure 1: STAMP Session-Sender test packet format with TLV in 194 unauthenticated mode 196 An implementation of STAMP Session-Reflector that supports this 197 specification SHOULD identify a STAMP Session using the SSID in 198 combination with elements of the usual 4-tuple. A conforming 199 implementation of STAMP Session-Reflector MUST copy the SSID value 200 from the received test packet and put it into the reflected packet as 201 displayed in Figure 2. 203 0 1 2 3 204 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 1 205 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 206 | Sequence Number | 207 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 208 | Timestamp | 209 | | 210 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 211 | Error Estimate | SSID | 212 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 213 | Receive Timestamp | 214 | | 215 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 216 | Session-Sender Sequence Number | 217 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 218 | Session-Sender Timestamp | 219 | | 220 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 221 | Session-Sender Error Estimate | MBZ | 222 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 223 |Ses-Sender TTL | MBZ | 224 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 225 | Type | Length | 226 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 227 ~ Value ~ 228 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 230 Figure 2: STAMP Session-Reflector test packet format with TLV in 231 unauthenticated mode 233 A STAMP Session-Reflector that does not support this specification, 234 will return the zeroed SSID field in the reflected STAMP test packet. 235 The Session-Sender MUST NOT stop the session if it receives a zeroed 236 SSID field. 238 In the authenticated mode, location of SSID field is shown in 239 Figure 3 and Figure 4. 241 0 1 2 3 242 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 1 243 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 244 | Sequence Number | 245 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 246 | | 247 | MBZ (12 octets) | 248 | | 249 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 250 | Timestamp | 251 | | 252 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 253 | Error Estimate | SSID | 254 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 255 ~ ~ 256 | MBZ (68 octets) | 257 ~ ~ 258 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 259 | | 260 | HMAC (16 octets) | 261 | | 262 | | 263 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 265 Figure 3: STAMP Session-Sender test packet format in authenticated 266 mode 268 0 1 2 3 269 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 1 270 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 271 | Sequence Number | 272 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 273 | MBZ (12 octets) | 274 | | 275 | | 276 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 277 | Timestamp | 278 | | 279 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 280 | Error Estimate | SSID | 281 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 282 | MBZ (4 octets) | 283 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 284 | Receive Timestamp | 285 | | 286 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 287 | MBZ (8 octets) | 288 | | 289 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 290 | Session-Sender Sequence Number | 291 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 292 | MBZ (12 octets) | 293 | | 294 | | 295 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 296 | Session-Sender Timestamp | 297 | | 298 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 299 | Session-Sender Error Estimate | | 300 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + 301 | MBZ (6 octets) | 302 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 303 |Ses-Sender TTL | | 304 +-+-+-+-+-+-+-+-+ + 305 | | 306 | MBZ (15 octets) | 307 | | 308 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 309 | HMAC (16 octets) | 310 | | 311 | | 312 | | 313 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 315 Figure 4: STAMP Session-Reflector test packet format in authenticated 316 mode 318 4. TLV Extensions to STAMP 320 Type-Length-Value (TLV) encoding scheme provides flexible extension 321 mechanism for optional informational elements. TLV is an optional 322 field in the STAMP test packet. TLVs have the two octets long Type 323 field, two octets long Length field that is the length of the Value 324 field in octets. Type values, see Section 5.1, less than 32768 325 identify mandatory TLVs that MUST be supported by an implementation. 326 Type values greater than or equal to 32768 identify optional TLVs 327 that SHOULD be ignored if the implementation does not understand or 328 support them. If a Type value for TLV or sub-TLV is in the range for 329 Vendor Private Use, the Length MUST be at least 4, and the first four 330 octets MUST be that vendor's the Structure of Management Information 331 (SMI) Private Enterprise Number, in network octet order. The rest of 332 the Value field is private to the vendor. Following sections 333 describe the use of TLVs for STAMP that extend STAMP capability 334 beyond its base specification. 336 A STAMP node, whether Session-Sender or Session-Reflector, receiving 337 a test packet MUST determine whether the packet is a base STAMP 338 packet or includes one or more TLVs. The node MUST compare the value 339 in the Length field of the UDP header and the length of the base 340 STAMP test packet in the mode, unauthenticated or authenticated based 341 on the configuration of the particular STAMP test session. If the 342 difference between the two values is larger than the length of UDP 343 header, then the test packet includes one or more STAMP TLVs that 344 immediately follow the base STAMP test packet. 346 A system that has received a STAMP test packet with extension TLVs 347 MUST validate each fixed-size TLV by verifying that the value in the 348 Length field equals the value defined for the particular type. If 349 the values are not equal, the processing of extension TLVs MUST be 350 stopped and the event logged (logging SHOULD be throttled). Also, if 351 the system is the Session-Reflector in that test, it MUST send 352 (transmission of ICMP Error messages SHOULD be throttled) the ICMP 353 Parameter Problem message with Code set to 0 and the Pointer 354 referring to the Length field of the TLV. 356 4.1. Extra Padding TLV 358 0 1 2 3 359 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 1 360 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 361 | Extra Padding Type | Length | 362 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 363 | | 364 ~ Extra Padding ~ 365 | | 366 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 368 Figure 5: Extra Padding TLV 370 where fields are defined as the following: 372 o Extra Padding Type - TBA1 allocated by IANA Section 5.1 374 o Length - two octets long field equals length on the Extra Padding 375 field in octets. 377 o Extra Padding - a pseudo-random sequence of numbers. The field 378 MAY be filled with all zeroes. 380 The Extra Padding TLV is similar to the Packet Padding field in 381 TWAMP-Test packet [RFC5357]. The Extra Padding TLV MUST be used to 382 create STAMP test packets of larger size. The Extra Padding TLV MUST 383 be the last TLV in a STAMP test packet. 385 4.2. Location TLV 387 STAMP session-sender MAY include the Location TLV to request 388 information from the session-reflector. The session-sender SHOULD 389 NOT fill any information fields except for Type and Length. The 390 session-reflector MUST validate the Length value against the address 391 family of the transport encapsulating the STAMP test packet. If the 392 value of the Length field is invalid, the session-reflector MUST zero 393 all fields and MUST NOT return any information to the session-sender. 394 The session-reflector MUST ignore all other fields of the received 395 Location TLV. 397 0 1 2 3 398 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 1 399 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 400 | Location Type | Length | 401 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 402 | Source MAC | 403 + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 404 | | Reserved | 405 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 406 ~ Destination IP Address ~ 407 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 408 ~ Source IP Address ~ 409 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 410 | Destination Port | Source Port | 411 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 413 Figure 6: Session-Reflector Location TLV 415 where fields are defined as the following: 417 o Location Type - TBA2 allocated by IANA Section 5.1 419 o Length - two octets long field equals length on the Value field in 420 octets. Length field value MUST be 20 octets for the IPv4 address 421 family. For the IPv6 address family value of the Length field 422 MUST be 44 octets. All other values are invalid. 424 o Source MAC - 6 octets 48 bits long field. The session-reflector 425 MUST copy Source MAC of received STAMP packet into this field. 427 o Reserved - two octets long field. MUST be zeroed on transmission 428 and ignored on reception. 430 o Destination IP Address - IPv4 or IPv6 destination address of the 431 received by the session-reflector STAMP packet. 433 o Source IP Address - IPv4 or IPv6 source address of the received by 434 the session-reflector STAMP packet. 436 o Destination Port - two octets long UDP destination port number of 437 the received STAMP packet. 439 o Source Port - two octets long UDP source port number of the 440 received STAMP packet. 442 The Location TLV MAY be used to determine the last-hop addressing for 443 STAMP packets including source and destination IP addresses as well 444 as the MAC address of the last-hop router. Last-hop MAC address MAY 445 be monitored by the Session-Sender whether there has been a path 446 switch on the last hop, closest to the Session-Reflector. The IP 447 addresses and UDP port will indicate if there is a NAT router on the 448 path, and allows the Session-Sender to identify the IP address of the 449 Session-Reflector behind the NAT, detect changes in the NAT mapping 450 that could cause sending the STAMP packets to the wrong Session- 451 Reflector. 453 4.3. Timestamp Information TLV 455 STAMP session-sender MAY include the Timestamp Information TLV to 456 request information from the session-reflector. The session-sender 457 SHOULD NOT fill any information fields except for Type and Length. 458 The session-reflector MUST validate the Length value of the STAMP 459 test packet. If the value of the Length field is invalid, the 460 session-reflector MUST zero all fields and MUST NOT return any 461 information to the session-sender. 463 0 1 2 3 464 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 1 465 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 466 | Timestamp Information Type | Length | 467 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 468 | Sync. Src In | Timestamp In | Sync. Src Out | Timestamp Out | 469 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 471 Figure 7: Timestamp Information TLV 473 where fields are defined as the following: 475 o Timestamp Information Type - TBA3 allocated by IANA Section 5.1 477 o Length - two octets long field, equals four octets. 479 o Sync Src In - one octet long field that characterizes the source 480 of clock synchronization at the ingress of Session-Reflector. 482 There are several of methods to synchronize the clock, e.g., 483 Network Time Protocol (NTP) [RFC5905], Precision Time Protocol 484 (PTP) [IEEE.1588.2008], Synchronization Supply Unit (SSU) or 485 Building Integrated Timing Supply (BITS), or Global Positioning 486 System (GPS), Global Orbiting Navigation Satellite System 487 (GLONASS) and Long Range Navigation System Version C (LORAN-C). 488 The value is one of the listed in Table 4. 490 o Timestamp In - one octet long field that characterizes the method 491 by which the ingress of Session-Reflector obtained the timestamp 492 T2. A timestamp may be obtained with hardware assist, via 493 software API from a local wall clock, or from a remote clock (the 494 latter referred to as "control plane"). The value is one of the 495 listed in Table 6. 497 o Sync Src Out - one octet long field that characterizes the source 498 of clock synchronization at the egress of Session-Reflector. The 499 value is one of the listed in Table 4. 501 o Timestamp Out - one octet long field that characterizes the method 502 by which the egress of Session-Reflector obtained the timestamp 503 T3. The value is one of the listed in Table 6. 505 4.4. Class of Service TLV 507 The STAMP session-sender MAY include Class of Service (CoS) TLV in 508 the STAMP test packet. If the CoS TLV is present in the STAMP test 509 packet and the value of the DSCP1 field is zero, then the STAMP 510 session-reflector MUST copy the values of Differentiated Services 511 Code Point (DSCP) ECN fields from the received STAMP test packet into 512 DSCP2 and ECN fields respectively of the CoS TLV of the reflected 513 STAMP test packet. If the value of the DSCP1 field is non-zero, then 514 the STAMP session-reflector MUST use DSCP1 value from the CoS TLV in 515 the received STAMP test packet as DSCP value of STAMP reflected test 516 packet and MUST copy DSCP and ECN values of the received STAMP test 517 packet into DSCP2 and ECN fields of Class of Service TLV in the STAMP 518 reflected a packet. The Session-Sender, upon receiving the reflected 519 packet, will save the DSCP and ECN values for analysis of the CoS in 520 the reverse direction. 522 0 1 2 3 523 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 1 524 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 525 | Class of Service Type | Length | 526 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 527 | DSCP1 | DSCP2 |ECN| Reserved | 528 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 530 Figure 8: Class of Service TLV 532 where fields are defined as the following: 534 o Class of Service Type - TBA4 allocated by IANA Section 5.1 536 o Length - two octets long field, equals four octets. 538 o DSCP1 - The Differentiated Services Code Point (DSCP) intended by 539 the Session-Sender. To be used as the return DSCP from the 540 Session-Reflector. 542 o DSCP2 - The received value in the DSCP field at the Session- 543 Reflector in the forward direction. 545 o ECN - The received value in the ECN field at the Session-Reflector 546 in the forward direction. 548 o Reserved - 18 bits long field, must be zeroed in transmission and 549 ignored on receipt. 551 A STAMP Session-Sender that includes the CoS TLV sets the value of 552 the DSCP1 field and zeroes the value of the DSCP2 field. A STAMP 553 Session-Reflector that received the test packet with the CoS TLV MUST 554 include the CoS TLV in the reflected test packet. Also, the Session- 555 Reflector MUST copy the value of the DSCP field of the IP header of 556 the received STAMP test packet into the DSCP2 field in the reflected 557 test packet. And, at last, the Session-Reflector MUST set the value 558 of the DSCP field in the IP header of the reflected test packet equal 559 to the value of the DSCP1 field of the test packet it has received. 561 Re-mapping of CoS in some use cases, for example, in mobile backhaul 562 networks is used to provide multiple services, i.e., 2G, 3G, LTE, 563 over the same network. But if it is misconfigured, then it is often 564 difficult to diagnose the root cause of the problem that is viewed as 565 an excessive packet drop of higher level service while packet drop 566 for lower service packets is at a normal level. Using CoS TLV in 567 STAMP test helps to troubleshoot the existing problem and also verify 568 whether DiffServ policies are processing CoS as required by the 569 configuration. 571 4.5. Direct Measurement TLV 573 The Direct Measurement TLV enables collection of "in profile" IP 574 packets that had been transmitted and received by the Session-Sender 575 and Session-Reflector respectfully. The definition of "in-profile 576 packet" is outside the scope of this document. 578 0 1 2 3 579 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 1 580 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 581 | Direct Measurement Type | Length | 582 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 583 | Session-Sender Tx counter (S_TxC) | 584 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 585 | Session-Reflector Rx counter (R_RxC) | 586 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 587 | Session-Reflector Tx counter (R_TxC) | 588 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 590 Figure 9: Direct Measurement TLV 592 where fields are defined as the following: 594 o Direct Measurement Type - TBA5 allocated by IANA Section 5.1 596 o Length - two octets long field equals length on the Value field in 597 octets. Length field value MUST be 12 octets. 599 o Session-Sender Tx counter (S_TxC) is four octets long field. 601 o Session-Reflector Rx counter (R_RxC) is four octets long field. 602 MUST be zeroed by the Session-Sender and filled by the Session- 603 Reflector. 605 o Session-Reflector Tx counter (R_TxC) is four octets long field. 606 MUST be zeroed by the Session-Sender and filled by the Session- 607 Reflector. 609 4.6. Access Report TLV 611 A STAMP Session-Sender MAY include Access Report TLV (Figure 10) to 612 indicate changes to the access network status to the Session- 613 Reflector. The definition of an access network is outside the scope 614 of this document. 616 0 1 2 3 617 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 1 618 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 619 | Access Report Type | Length | 620 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 621 | Access ID | Return Code | Reserved | 622 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 624 Figure 10: Access Report TLV 626 where fields are defined as follows: 628 o Access Report Type - TBA6 allocated by IANA Section 5.1. 630 o Length - two octets long field, equals four octets. 632 o Access ID - one octet long field that identifies the access 633 network, e.g., 3GPP (Radio Access Technologies specified by 3GPP) 634 or Non-3GPP (accesses that are not specified by 3GPP) [TS23501]. 635 The value is one of Section 5.4. 637 o Return Code - one octet long field that identifies the report 638 signal, e.g., available, unavailable. The value is one of 639 Section 5.5. 641 o Reserved - two octets long field, must be zeroed on transmission 642 and ignored on receipt. 644 The STAMP Session-Sender that includes the Access Report TLV sets the 645 value of the Access ID field according to the type of access network 646 it reports on. Also, the Session-Sender sets the value of the Return 647 Code field to reflect the operational state of the access network. 648 The mechanism to determine the state of the access network is outside 649 the scope of this specification. A STAMP Session-Reflector that 650 received the test packet with the Access Report TLV MUST include the 651 Access Report TLV in the reflected test packet. The Session- 652 Reflector MUST set the value of the Access ID and Return Code fields 653 equal to the values of the corresponding fields from the test packet 654 it has received. 656 The Session-Sender MUST also arm a retransmission timer after sending 657 a test packet that includes the Access Report TLV. This timer MUST 658 be disarmed upon the reception of the reflected STAMP test packet 659 that includes Access Report TLV. In the event the timer expires 660 before such a packet is received, the Session-Sender MUST retransmit 661 the STAMP test packet that contains the Access Report TLV. This 662 retransmission SHOULD be repeated up to four times before the 663 procedure is aborted. Setting the value for the retransmission timer 664 is based on local policies, network environment. The default value 665 of the retransmission timer for Access Report TLV SHOULD be three 666 seconds. An implementation MUST provide control of the 667 retransmission timer value and the number of retransmissions. 669 The Access Report TLV is used by the Performance Measurement Function 670 (PMF) components of the Access Steering, Switching and Splitting 671 feature for 5G networks [TS23501]. The PMF component in the User 672 Equipment acts as the STAMP Session-Sender, and the PMF component in 673 the User Plane Function acts as the STAMP Session-Reflector. 675 4.7. Follow-up Telemetry TLV 677 A Session-Reflector might be able to put in the Timestamp field only 678 a "SW Local" (see Table 6) timestamp. But the hosting system might 679 provide the timestamp closer to the start of actual packet 680 transmission even though when it is not possible to deliver the 681 information to the Session-Sender in the packet itself. This 682 timestamp might nevertheless be important for the Session-Sender, as 683 it helps in to improve the accuracy of measuring network delay by 684 minimizing the impact of egress queuing delays on the measurement. 686 A STAMP Session-Sender MAY include the Follow-up Telemetry TLV to 687 request information from the Session-Reflector. The Session-Sender 688 MUST set the Follow-up Telemetry Type and Length fields to their 689 appropriate values. Sequence Number and Timestamp fields MUST be 690 zeroed on transmission by the Session-Sender and ignored by the 691 Session-Reflector upon receipt of the STAMP test packet that includes 692 the Follow-up Telemetry TLV. The Session-Reflector MUST validate the 693 Length value of the STAMP test packet. If the value of the Length 694 field is invalid, the Session-Reflector MUST zero Sequence Number and 695 Timestamp fields. If the Session-Reflector is in stateless mode 696 (defined in Section 4.2 [RFC8762]), it MUST zero Sequence Number and 697 Timestamp fields. 699 0 1 2 3 700 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 1 701 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 702 | Follow-up Telemetry Type | Length | 703 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 704 | Sequence Number | 705 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 706 | Follow-up Timestamp | 707 | | 708 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 709 | Timestamp M | Reserved | 710 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 712 Figure 11: Follow-up Telemetry TLV 714 where fields are defined as follows: 716 o Follow-up Telemetry Type - TBA7 allocated by IANA Section 5.1. 718 o Length - two octets long field, equals 16 octets. 720 o Sequence Number - four octets long field indicating the sequence 721 number of the last packet reflected in the same STAMP-test 722 session. Since the Session-Reflector runs in the stateful mode 723 (defined in Section 4.2 [RFC8762]), it is the Session-Reflector's 724 Sequence Number of the previous reflected packet. 726 o Follow-up Timestamp - eight octets long field, with the format 727 indicated by the Z flag of the Error Estimate field of the packet 728 transmitted by a Session-Reflector, as described in Section 4.1 729 [RFC8762]. It carries the timestamp when the reflected packet 730 with the specified sequence number was sent.. 732 o Timestamp M(ode) - one octet long field that characterizes the 733 method by which the entity that transmits a reflected STAMP packet 734 obtained the Follow-up Timestamp. The value is one of the listed 735 in Table 6. 737 o Reserved - the three octest-long field. Its value MUST be zeroed 738 on transmission and ignored on receipt. 740 4.8. HMAC TLV 742 The STAMP authenticated mode protects the integrity of data collected 743 in STAMP base packet. STAMP extensions are designed to provide 744 valuable information about the condition of a network, and protecting 745 the integrity of that data is also essential. The keyed Hashed 746 Message Authentication Code (HMAC) TLV MUST be included in a STAMP 747 test packet in the authenticated mode, excluding when the only TLV 748 present is Extra Padding TLV. The HMAC TLV MUST follow all TLVs 749 included in a STAMP test packet, except for the Extra Padding TLV. 750 The HMAC TLV MAY be used to protect the integrity of STAMP extensions 751 in STAMP unauthenticated mode. 753 0 1 2 3 754 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 1 755 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 756 | HMAC Type | Length | 757 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 758 | | 759 | HMAC | 760 | | 761 | | 762 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 764 Figure 12: HMAC TLV 766 where fields are defined as follows: 768 o HMAC Type - is two octets long field, value TBA8 allocated by IANA 769 Section 5.1. 771 o Length - two octets long field, equals 16 octets. 773 o HMAC - is 16 octets long field that carries HMAC digest of the 774 text of all preceding TLVs. 776 As defined in [RFC8762], STAMP uses HMAC-SHA-256 truncated to 128 777 bits ([RFC4868]). All considerations regarding using the key and key 778 distribution and management listed in Section 4.4 of [RFC8762] are 779 fully applicable to the use of the HMAC TLV. HMAC is calculated as 780 defined in [RFC2104] over text as the concatenation of all preceding 781 TLVs. The digest then MUST be truncated to 128 bits and written into 782 the HMAC field. In the authenticated mode, HMAC MUST be verified 783 before using any data in the included STAMP TLVs. If HMAC 784 verification by the Session-Reflector fails, then an ICMP Parameter 785 Problem message MUST be generated (with consideration of limiting the 786 rate of error messages). The Code value MUST be set to 0 and the 787 Pointer identifying HMAC Type. Also, both Session-Sender and 788 Session-Reflector SHOULD log the notification that HMAC verification 789 of STAMP TLVs failed. The packet that failed HMAC verification MUST 790 be dropped. 792 5. IANA Considerations 794 5.1. STAMP TLV Registry 796 IANA is requested to create the STAMP TLV Type registry. All code 797 points in the range 1 through 32759 in this registry shall be 798 allocated according to the "IETF Review" procedure as specified in 799 [RFC8126]. Code points in the range 32760 through 65279 in this 800 registry shall be allocated according to the "First Come First 801 Served" procedure as specified in [RFC8126]. Remaining code points 802 are allocated according to Table 1: 804 +---------------+-------------------------+-------------------------+ 805 | Value | Description | Reference | 806 +---------------+-------------------------+-------------------------+ 807 | 0 | Reserved | This document | 808 | 1- 32767 | Mandatory TLV, | IETF Review | 809 | | unassigned | | 810 | 32768 - 65279 | Optional TLV, | First Come First Served | 811 | | unassigned | | 812 | 65280 - 65519 | Experimental | This document | 813 | 65520 - 65534 | Private Use | This document | 814 | 65535 | Reserved | This document | 815 +---------------+-------------------------+-------------------------+ 817 Table 1: STAMP TLV Type Registry 819 This document defines the following new values in the STAMP TLV Type 820 registry: 822 +-------+-----------------------+---------------+ 823 | Value | Description | Reference | 824 +-------+-----------------------+---------------+ 825 | TBA1 | Extra Padding | This document | 826 | TBA2 | Location | This document | 827 | TBA3 | Timestamp Information | This document | 828 | TBA4 | Class of Service | This document | 829 | TBA5 | Direct Measurement | This document | 830 | TBA6 | Access Report | This document | 831 | TBA7 | Follow-up Telemetry | This document | 832 | TBA8 | HMAC | This document | 833 +-------+-----------------------+---------------+ 835 Table 2: STAMP Types 837 5.2. Synchronization Source Sub-registry 839 IANA is requested to create Synchronization Source sub-registry as 840 part of STAMP TLV Type registry. All code points in the range 1 841 through 127 in this registry shall be allocated according to the 842 "IETF Review" procedure as specified in [RFC8126]. Code points in 843 the range 128 through 239 in this registry shall be allocated 844 according to the "First Come First Served" procedure as specified in 845 [RFC8126]. Remaining code points are allocated according to Table 1: 847 +-----------+--------------+-------------------------+ 848 | Value | Description | Reference | 849 +-----------+--------------+-------------------------+ 850 | 0 | Reserved | This document | 851 | 1- 127 | Unassigned | IETF Review | 852 | 128 - 239 | Unassigned | First Come First Served | 853 | 240 - 249 | Experimental | This document | 854 | 250 - 254 | Private Use | This document | 855 | 255 | Reserved | This document | 856 +-----------+--------------+-------------------------+ 858 Table 3: Synchronization Source Sub-registry 860 This document defines the following new values in the Synchronization 861 Source sub-registry: 863 +-------+---------------------+---------------+ 864 | Value | Description | Reference | 865 +-------+---------------------+---------------+ 866 | 1 | NTP | This document | 867 | 2 | PTP | This document | 868 | 3 | SSU/BITS | This document | 869 | 4 | GPS/GLONASS/LORAN-C | This document | 870 | 5 | Local free-running | This document | 871 +-------+---------------------+---------------+ 873 Table 4: Synchronization Sources 875 5.3. Timestamping Method Sub-registry 877 IANA is requested to create Timestamping Method sub-registry as part 878 of STAMP TLV Type registry. All code points in the range 1 through 879 127 in this registry shall be allocated according to the "IETF 880 Review" procedure as specified in [RFC8126]. Code points in the 881 range 128 through 239 in this registry shall be allocated according 882 to the "First Come First Served" procedure as specified in [RFC8126]. 883 Remaining code points are allocated according to Table 1: 885 +-----------+--------------+-------------------------+ 886 | Value | Description | Reference | 887 +-----------+--------------+-------------------------+ 888 | 0 | Reserved | This document | 889 | 1- 127 | Unassigned | IETF Review | 890 | 128 - 239 | Unassigned | First Come First Served | 891 | 240 - 249 | Experimental | This document | 892 | 250 - 254 | Private Use | This document | 893 | 255 | Reserved | This document | 894 +-----------+--------------+-------------------------+ 896 Table 5: Timestamping Method Sub-registry 898 This document defines the following new values in the Timestamping 899 Methods sub-registry: 901 +-------+---------------+---------------+ 902 | Value | Description | Reference | 903 +-------+---------------+---------------+ 904 | 1 | HW Assist | This document | 905 | 2 | SW local | This document | 906 | 3 | Control plane | This document | 907 +-------+---------------+---------------+ 909 Table 6: Timestamping Methods 911 5.4. Access ID Sub-registry 913 IANA is requested to create Access ID sub-registry as part of STAMP 914 TLV Type registry. All code points in the range 1 through 127 in 915 this registry shall be allocated according to the "IETF Review" 916 procedure as specified in [RFC8126]. Code points in the range 128 917 through 239 in this registry shall be allocated according to the 918 "First Come First Served" procedure as specified in [RFC8126]. 919 Remaining code points are allocated according to Table 7: 921 +-----------+--------------+-------------------------+ 922 | Value | Description | Reference | 923 +-----------+--------------+-------------------------+ 924 | 0 | Reserved | This document | 925 | 1- 127 | Unassigned | IETF Review | 926 | 128 - 239 | Unassigned | First Come First Served | 927 | 240 - 249 | Experimental | This document | 928 | 250 - 254 | Private Use | This document | 929 | 255 | Reserved | This document | 930 +-----------+--------------+-------------------------+ 932 Table 7: Access ID Sub-registry 934 This document defines the following new values in the Access ID sub- 935 registry: 937 +-------+-------------+---------------+ 938 | Value | Description | Reference | 939 +-------+-------------+---------------+ 940 | 1 | 3GPP | This document | 941 | 2 | Non-3GPP | This document | 942 +-------+-------------+---------------+ 944 Table 8: Access IDs 946 5.5. Return Code Sub-registry 948 IANA is requested to create Return Code sub-registry as part of STAMP 949 TLV Type registry. All code points in the range 1 through 127 in 950 this registry shall be allocated according to the "IETF Review" 951 procedure as specified in [RFC8126]. Code points in the range 128 952 through 239 in this registry shall be allocated according to the 953 "First Come First Served" procedure as specified in [RFC8126]. 954 Remaining code points are allocated according to Table 7: 956 +-----------+--------------+-------------------------+ 957 | Value | Description | Reference | 958 +-----------+--------------+-------------------------+ 959 | 0 | Reserved | This document | 960 | 1- 127 | Unassigned | IETF Review | 961 | 128 - 239 | Unassigned | First Come First Served | 962 | 240 - 249 | Experimental | This document | 963 | 250 - 254 | Private Use | This document | 964 | 255 | Reserved | This document | 965 +-----------+--------------+-------------------------+ 967 Table 9: Return Code Sub-registry 969 This document defines the following new values in the Return Code 970 sub-registry: 972 +-------+---------------------+---------------+ 973 | Value | Description | Reference | 974 +-------+---------------------+---------------+ 975 | 1 | Network available | This document | 976 | 2 | Network unavailable | This document | 977 +-------+---------------------+---------------+ 979 Table 10: Return Codes 981 6. Security Considerations 983 Use of HMAC in authenticated mode may be used to simultaneously 984 verify both the data integrity and the authentication of the STAMP 985 test packets. 987 7. Acknowledgments 989 Authors much appreciate the thorough review and thoughful comments 990 received from Tianran Zhou. 992 8. Contributors 994 The following people contributed text to this document: 996 Guo Jun 997 ZTE Corporation 998 68# Zijinghua Road 999 Nanjing, Jiangsu 210012 1000 P.R.China 1002 Phone: +86 18105183663 1003 Email: guo.jun2@zte.com.cn 1005 9. References 1007 9.1. Normative References 1009 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 1010 Requirement Levels", BCP 14, RFC 2119, 1011 DOI 10.17487/RFC2119, March 1997, 1012 . 1014 [RFC5357] Hedayat, K., Krzanowski, R., Morton, A., Yum, K., and J. 1015 Babiarz, "A Two-Way Active Measurement Protocol (TWAMP)", 1016 RFC 5357, DOI 10.17487/RFC5357, October 2008, 1017 . 1019 [RFC8126] Cotton, M., Leiba, B., and T. Narten, "Guidelines for 1020 Writing an IANA Considerations Section in RFCs", BCP 26, 1021 RFC 8126, DOI 10.17487/RFC8126, June 2017, 1022 . 1024 [RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 1025 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, 1026 May 2017, . 1028 [RFC8762] Mirsky, G., Jun, G., Nydell, H., and R. Foote, "Simple 1029 Two-Way Active Measurement Protocol", RFC 8762, 1030 DOI 10.17487/RFC8762, March 2020, 1031 . 1033 9.2. Informative References 1035 [IEEE.1588.2008] 1036 "Standard for a Precision Clock Synchronization Protocol 1037 for Networked Measurement and Control Systems", 1038 IEEE Standard 1588, March 2008. 1040 [RFC2104] Krawczyk, H., Bellare, M., and R. Canetti, "HMAC: Keyed- 1041 Hashing for Message Authentication", RFC 2104, 1042 DOI 10.17487/RFC2104, February 1997, 1043 . 1045 [RFC4868] Kelly, S. and S. Frankel, "Using HMAC-SHA-256, HMAC-SHA- 1046 384, and HMAC-SHA-512 with IPsec", RFC 4868, 1047 DOI 10.17487/RFC4868, May 2007, 1048 . 1050 [RFC5905] Mills, D., Martin, J., Ed., Burbank, J., and W. Kasch, 1051 "Network Time Protocol Version 4: Protocol and Algorithms 1052 Specification", RFC 5905, DOI 10.17487/RFC5905, June 2010, 1053 . 1055 [TS23501] 3GPP (3rd Generation Partnership Project), "Technical 1056 Specification Group Services and System Aspects; System 1057 Architecture for the 5G System; Stage 2 (Release 16)", 1058 3GPP TS23501, 2019. 1060 Authors' Addresses 1062 Greg Mirsky 1063 ZTE Corp. 1065 Email: gregimirsky@gmail.com 1067 Xiao Min 1068 ZTE Corp. 1070 Email: xiao.min2@zte.com.cn 1071 Henrik Nydell 1072 Accedian Networks 1074 Email: hnydell@accedian.com 1076 Richard Foote 1077 Nokia 1079 Email: footer.foote@nokia.com 1081 Adi Masputra 1082 Apple Inc. 1083 One Apple Park Way 1084 Cupertino, CA 95014 1085 USA 1087 Email: adi@apple.com 1089 Ernesto Ruffini 1090 OutSys 1091 via Caracciolo, 65 1092 Milano 20155 1093 Italy 1095 Email: eruffini@outsys.org