idnits 2.17.00 (12 Aug 2021) /tmp/idnits3492/draft-wang-ippm-stamp-hbh-extensions-03.txt: Checking boilerplate required by RFC 5378 and the IETF Trust (see https://trustee.ietf.org/license-info): ---------------------------------------------------------------------------- No issues found here. Checking nits according to https://www.ietf.org/id-info/1id-guidelines.txt: ---------------------------------------------------------------------------- No issues found here. Checking nits according to https://www.ietf.org/id-info/checklist : ---------------------------------------------------------------------------- No issues found here. Miscellaneous warnings: ---------------------------------------------------------------------------- == The copyright year in the IETF Trust and authors Copyright Line does not match the current year -- The document date (February 22, 2021) is 446 days in the past. Is this intentional? Checking references for intended status: Proposed Standard ---------------------------------------------------------------------------- (See RFCs 3967 and 4897 for information about using normative references to lower-maturity documents in RFCs) -- Looks like a reference, but probably isn't: '0' on line 139 -- Looks like a reference, but probably isn't: '1' on line 668 Summary: 0 errors (**), 0 flaws (~~), 1 warning (==), 3 comments (--). Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 2 IP Performance Measurement Group Y. Wang 3 Internet-Draft T. Zhou 4 Intended status: Standards Track Huawei 5 Expires: August 26, 2021 H. Yang 6 China Mobile 7 C. Liu 8 China Unicom 9 February 22, 2021 11 Simple Two-way Active Measurement Protocol Extensions for Hop-by-Hop OAM 12 Data Collection 13 draft-wang-ippm-stamp-hbh-extensions-03 15 Abstract 17 This document defines optional TLVs which are carried in Simple Two- 18 way Active Measurement Protocol (STAMP) test packets to enhance the 19 STAMP base functions. Such extensions to STAMP enable OAM data 20 measurement and collection at every node and link along a STAMP test 21 packet's delivery path without maintaining a state for each 22 configured STAMP-Test session at every devices. 24 Requirements Language 26 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 27 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this 28 document are to be interpreted as described in RFC 2119 [RFC2119]. 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 August 26, 2021. 47 Copyright Notice 49 Copyright (c) 2021 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 . . . . . . . . . . . . . . . . . . . . . . . . 2 65 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3 66 3. TLV Extensions to STAMP . . . . . . . . . . . . . . . . . . . 3 67 3.1. IOAM-Tracing-Data TLV . . . . . . . . . . . . . . . . . . 3 68 3.2. Forward HbH Delay TLV . . . . . . . . . . . . . . . . . . 5 69 3.3. Backward HbH Delay TLV . . . . . . . . . . . . . . . . . 7 70 3.4. HbH Direct Loss TLV . . . . . . . . . . . . . . . . . . . 9 71 3.5. HbH Bandwidth Utilization TLV . . . . . . . . . . . . . . 11 72 3.6. HbH Timestamp Information TLV . . . . . . . . . . . . . . 12 73 3.7. HbH Interface Errors TLV . . . . . . . . . . . . . . . . 14 74 4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 16 75 5. Security Considerations . . . . . . . . . . . . . . . . . . . 16 76 6. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 16 77 7. References . . . . . . . . . . . . . . . . . . . . . . . . . 16 78 7.1. Normative References . . . . . . . . . . . . . . . . . . 16 79 7.2. Informative References . . . . . . . . . . . . . . . . . 17 80 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 17 82 1. Introduction 84 Simple Two-way Active Measurement Protocol (STAMP) [RFC8762] enables 85 the measurement of both one-way and round-trip performance metrics, 86 such as delay, delay variation, and packet loss. In the STAMP 87 session, the bidirectional packet flow is transmitted between STAMP 88 Session-Sender and STAMP Session-Reflector. The STAMP Session- 89 Reflector receives test packets transmitted from Session-Sender and 90 acts according to the configuration. However, the performance of 91 intermediate nodes and links that STAMP test packets traverse are 92 invisible. In addition, the STAMP instance must be configured at 93 every intermediate node to measure the performance per node and link 94 that test packets traverse, which increases the complexity of OAM in 95 large-scale networks. 97 STAMP Extensions have defined several optional TLVs to enhance the 98 STAMP base functions. These optional TLVs are defined as updates of 99 the STAMP Optional Extensions [RFC8972]. This document extents 100 optional TLVs to STAMP, which enables performance measurement at 101 every intermediate node and link along a STAMP test packet's delivery 102 path, such as measurement of delay, delay variation, packet loss, and 103 record of link errors and route information. The following sections 104 describe the use of TLVs for STAMP that extend STAMP capability 105 beyond its base specification. 107 2. Terminology 109 Following are abbreviations used in this document: 111 STAMP: Simple Two-way Active Measurement Protocol. 113 IOAM: In-situ OAM. 115 HbH: Hop-by-Hop. 117 3. TLV Extensions to STAMP 119 3.1. IOAM-Tracing-Data TLV 121 STAMP Session-Sender MAY place the IOAM-Tracing-Data TLV in Session- 122 Sender test packets to record the IOAM tracing data at every IOAM 123 capable node along the Session-Sender test packet's forward-delivery 124 path. As STAMP uses symmetrical packets, the Session-Sender MUST set 125 the Length value as a multiple of 4 octets according to the number of 126 nodes and the IOAM-Trace-Type (i.e. a 24-bit identifier which 127 specifies which data types are used in the node data list 128 [I-D.ietf-ippm-ioam-data]). And the node-data-copied-list fields 129 MUST be set to zero upon Session-Sender test packets transmission and 130 ignored upon receipt. 132 The IOAM-Tracing-Data TLV has the following format: 134 0 1 2 3 135 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 1 136 +-------------------------------+-------------------------------+ 137 | IOAM-Tracing-Data Type | Length | 138 +---------------------------------------------------------------+ 139 | node-data-copied-list [0] | 140 +---------------------------------------------------------------+ 141 | node-data-copied-list [1] | 142 +---------------------------------------------------------------+ 143 ~ ... ~ 144 +---------------------------------------------------------------+ 145 | node-data-copied-list [n] | 146 +---------------------------------------------------------------+ 148 Fig. 1 IOAM-Tracing-Data TLV Format 150 where fields are defined as the following: 152 o IOAM-Tracing-Data Type: To be assigned by IANA. 154 o Length: A 2-octet field that indicates the length of the value 155 field in octets and equal to a multiple of 4 octets dependent on 156 the number of nodes and IOAM-Trace-Type bits. 158 o node-data-copied-list [0..n]: A variable-length field, which 159 record the copied content of each node data element determined by 160 the IOAM-Trace-Type. The order of packing the data fields in each 161 node data element follows the bit order of the IOAM-Trace-Type 162 field (see section 4.4.1 of [I-D.ietf-ippm-ioam-data]). The last 163 node data element in this list is the node data of the first IOAM 164 trace capable node in the path. 166 In an IOAM domain, the STAMP Session-Sender and the STAMP Session- 167 Reflector MAY be configured as the IOAM encapsulating node and the 168 IOAM decapsulating node. The STAMP Session-Sender (i.e. the IOAM 169 encapsulating node) generates the test packet with the IOAM Tracing 170 Data TLV. For applying the IOAM Trace-Option functionalities to the 171 Session-Sender test packet, the Session-Sender must inserts the 172 "trace option header" and allocate an node-data-list array 173 [I-D.ietf-ippm-ioam-data] into "option data" fields of Hop-by-Hop 174 Options header in IPv6 packets [I-D.ietf-ippm-ioam-ipv6-options], and 175 sets the corresponding bits in the IOAM-Trace-Type. Also, the STAMP 176 Session-Sender allocates a node-data-copied-list array in the 177 optional IOAM-Tracing-Data TLV to store OAM data retrieved from every 178 IOAM transit node along the Session-Sender test packet's delivery 179 path. 181 When the STAMP Session-Reflector (i.e. the IOAM decapsulating node) 182 received the STAMP Session-Sender test packet with the IOAM-Tracing- 183 Data TLV, it MUST copy the node-data-list array into the node-data- 184 copied-list array carried in the Session-Reflector test packet before 185 transmission and MUST remove the IOAM-Data-Fields. Hence, carrying 186 IOAM-Tracing-Data TLV in STAMP test packets enables OAM data 187 collection and measurement at every node and link. 189 Also the STAMP Session-Reflector MAY be configured as IOAM 190 encapsulating node to apply the IOAM Trace-Option functionalities to 191 the Session-Reflector test packet. Hence, OAM data collection and 192 measurement can be also enabled at every node and link along the 193 Session-Reflector test packet's backward delivery path. When the 194 reflected packet arrives at the Session-Sender, it can be either 195 locally processed or sent to the centralized controller. 197 3.2. Forward HbH Delay TLV 199 STAMP Session-Sender MAY place the Forward HbH Delay TLV in Session- 200 Sender test packets to record the ingress timestamp and the egress 201 timestamp at every intermediate nodes along the Session-Sender test 202 packet's forward path. The Session-Sender MUST set the Length value 203 according to the number of explicitly listed intermediate nodes in 204 the forward path and the timestamp formats. There are several 205 methods to synchronize the clock, e.g., Network Time Protocol (NTP) 206 [RFC5905] and IEEE 1588v2 Precision Time Protocol (PTP) 207 [IEEE.1588.2008]. For example, if a 64-bit timestamp format defined 208 in NTP is used, the Length value MUST be set as a multiple of 16 209 octets. The Timestamp Tuple list [1..n] fields MUST be set to zero 210 upon Session-Sender test packets transmission. 212 The Forward HbH Delay TLV has the following format: 214 0 1 2 3 215 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 1 216 +-------------------------------+---------------+---------------+ 217 | Forward HbH Delay Type | Length | Node Left | 218 +-------------------------------+---------------+---------------+ 219 | | 220 | Timestamp Tuple list [1] | 221 | | 222 | | 223 +---------------------------------------------------------------+ 224 ~ ... ~ 225 +---------------------------------------------------------------+ 226 | | 227 | Timestamp Tuple list [n] | 228 | | 229 | | 230 +---------------------------------------------------------------+ 232 Fig. 2 Forward HbH Delay TLV Format 234 where fields are defined as the following: 236 o Forward HbH Delay Type: To be assigned by IANA. 238 o Length: A 8-bit field that indicates the length of the value 239 portion in octets and MUST be a multiple of 16 octets according to 240 the number of explicitly listed intermediate nodes in the forward 241 path. 243 o Node Left: A 8-bit unsigned integer, which indicates the number of 244 intermediate nodes remaining. That is, number of explicitly 245 listed intermediate nodes still to be visited before reaching the 246 destination node in the forward path. The Node Left field is set 247 to n-1, where n is the number of intermediate nodes. 249 o Timestamp Tuple list [1..n]: A variable-length field, which record 250 the timestamp when the Session-Sender test packet is received at 251 the ingress of the n-th intermediate node and the timestamp when 252 the Session-Sender test packet is sent at egress of the n-th 253 intermediate node. For example, if a 64-bit timestamp format 254 defined in NTP is used, the length of each Timestamp Tuple 255 (ingress timestamp [n], egress timestamp [n]) must be 16 octets. 256 The Timestamp Tuple list is encoded starting from the last 257 intermediate node which is explicitly listed. That is, the first 258 element of the Timestamp Tuple list [1] records the timestamps 259 when the Session-Sender test packet received and forwarded at the 260 last intermediate node of a explicit path, the second element 261 records the penultimate Timestamp Tuple when the Session-Sender 262 test packet received and forwarded at the penultimate intermediate 263 node of a explicit path, and so on. 265 In the following reference topology, Node N1, N2, N3, N4 and N5 are 266 SRv6 capable nodes. Node N1 is the STAMP Session-Sender and Node N5 267 is the STAMP Session-Reflector. T1 is the Timestamp taken by the 268 Session-Sender (i.e. N1) at the start of transmitting the test 269 packet. T2 is the Receive Timestamp when the test packet was 270 received by the Session-Reflector (i.e. N5). T3 is the Timestamp 271 taken by the Session-Reflector at the start of transmitting the test 272 packet. T4 is the Receive Timestamp when the test packet was 273 received by the Session-Sender. Timestamp tuples (t1,t2), (t3,t4) 274 and (t5,t6) are the timestamps when the test packet received and 275 transmitted by sequence of intermediate nodes in the forward path. 276 Timestamp Tuples (t7,t8), (t9,t10) and (t11,t12) are the timestamps 277 when the test packet received and transmitted by sequence of 278 intermediate nodes in the backward path. 280 ====== ====== ====== ====== ====== 281 | | T1--->t1 | | t2--->t3 | | t4--->t5 | | t6--->T2| | 282 | N1 |==========| N2 |==========| N3 |==========| N4 |=========| N5 | 283 | | T4<---t12| |t11<---t10| | t9<---t8 | | t7<---T3| | 284 ====== ====== ====== ====== ====== 286 Fig. 3 Reference Topology 288 The STAMP Session-Sender (i.e. Node N1) generates the STAMP test 289 packet with the Forward HbH Delay TLV. When an intermediate node 290 receives the STAMP test packet, the node punts the packet to control 291 plane and fills the ingress timestamp [n] filed in the Timestamp 292 Tuple list [n]. Then the time taken by the intermediate node 293 transmitting the test packet is recorded in to egress timestamp [n] 294 field. The mechanism of timestamping and punting packet to control 295 plane is outside the scope of this specification. 297 When the STAMP Session-Reflector received the test packet with the 298 Forward HbH Delay TLV, it MUST copy the Forward HbH Delay TLV into 299 the Session-Reflector test packet before its transmission. Using 300 Forward HbH Delay TLV in STAMP testing enables delay measurement per 301 link in the forward path. 303 3.3. Backward HbH Delay TLV 305 STAMP Session-Sender MAY place the Backward HbH Delay TLV in Session- 306 Sender test packets to record the ingress timestamp and egress 307 timestamp when Session-Reflector test packets are received and sent 308 at every intermediate nodes in the backward path. The Session-Sender 309 MUST set the Length value according to the number of explicitly 310 listed intermediate nodes in the backward path and the timestamp 311 formats. There are several methods to synchronize the clock, e.g., 312 Network Time Protocol (NTP) [RFC5905] and IEEE 1588v2 Precision Time 313 Protocol (PTP) [IEEE.1588.2008]. For example, if a 64-bit timestamp 314 format defined in NTP is used, the Length value MUST be set as a 315 multiple of 16 octets. The Timestamp Tuple list [1..n] fields MUST 316 be set to zero upon Session-Sender test packets transmission and 317 ignored upon receipt. 319 The Backward HbH Delay TLV has the following format: 321 0 1 2 3 322 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 1 323 +-------------------------------+---------------+---------------+ 324 | Backward HbH Delay Type | Length | Node Left | 325 +-------------------------------+---------------+---------------+ 326 | | 327 | Timestamp Tuple list [1] | 328 | | 329 | | 330 +---------------------------------------------------------------+ 331 ~ ... ~ 332 +---------------------------------------------------------------+ 333 | | 334 | Timestamp Tuple list [n] | 335 | | 336 | | 337 +---------------------------------------------------------------+ 339 Fig. 4 Backward HbH Delay TLV Format 341 where fields are defined as the following: 343 o Backward HbH Delay Type: To be assigned by IANA. 345 o Length: A 8-bit field that indicates the length of the value 346 portion in octets and will be a multiple of 16 octets dependent on 347 the number of explicitly listed intermediate nodes in the backward 348 path. 350 o Node Left: A 8-bit unsigned integer, which indicates the number of 351 intermediate nodes remaining. That is, number of explicitly 352 listed intermediate nodes still to be visited before reaching the 353 destination node in the backward path. The Node Left field is set 354 to n-1, where n is the number of intermediate nodes. 356 o Timestamp Tuple list [1..n]: A variable-length field, which record 357 the timestamp when the reflected test packet is received at the 358 ingress of the n-th intermediate node and the timestamp when the 359 reflected test packet is sent at egress of the n-th intermediate 360 node. For example, if a 64-bit timestamp format defined in NTP is 361 used, the length of each Timestamp tuple (ingress timestamp [n], 362 egress timestamp [n]) must be 16 octets. The Timestamp Tuple list 363 is encoded starting from the last intermediate node which is 364 explicitly listed. That is, the first element of the Timestamp 365 Tuple list [1] records the timestamps when the reflected test 366 packet received and forwarded at the last intermediate node of a 367 explicit path, the second element records the penultimate 368 Timestamp Tuple when the reflected test packet received and 369 forwarded at the penultimate intermediate node of a explicit path, 370 and so on. 372 When the STAMP Session-Reflector received the Session-Sender test 373 packet with the Backward HbH Delay TLV, it MUST copy the Backward HbH 374 Delay TLV into the Session-Reflector test packet. 376 When an intermediate node receives the reflected test packet, the 377 node sends the packet to control plane and fills the ingress 378 timestamp [n] filed of Backward HbH Delay TLV. Then the time taken 379 by the intermediate node transmitting the test packet is recorded in 380 to egress timestamp [n] field of Backward HbH Delay TLV. Using 381 Backward HbH Delay TLV in STAMP testing enables delay measurement per 382 link in the backward path. 384 3.4. HbH Direct Loss TLV 386 STAMP Session-Sender MAY place the HbH Direct Loss TLV in Session- 387 Sender test packets to record the number of packets that form a 388 specific data flow received at and transmitted by every intermediate 389 nodes along the forward path. The Session-Sender MUST set the Length 390 value according to the number of explicitly listed intermediate nodes 391 in the forward path. A Counter Tuple is composed of a 64-bit Receive 392 Counter field and a 64-bit Transmit Counter field. The Counter Tuple 393 list [1..n] fields MUST be set to zero upon Session-Sender test 394 packets transmission. 396 The HbH Direct Loss TLV has the following format: 398 0 1 2 3 399 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 1 400 +-------------------------------+---------------+---------------+ 401 | HbH Direct Loss Type | Length | Node Left | 402 +-------------------------------+---------------+---------------+ 403 | | 404 | Counter Tuple list [1] | 405 | | 406 | | 407 +---------------------------------------------------------------+ 408 ~ ... ~ 409 +---------------------------------------------------------------+ 410 | | 411 | Counter Tuple list [n] | 412 | | 413 | | 414 +---------------------------------------------------------------+ 416 Fig. 5 HbH Direct Loss TLV Format 418 where fields are defined as the following: 420 o HbH Direct Loss Type: To be assigned by IANA. 422 o Length: A 8-bit field that indicates the length of the value 423 portion in octets and will be a multiple of 16 octets dependent on 424 the number of explicitly listed intermediate nodes in the forward 425 path. 427 o Node Left: A 8-bit unsigned integer, which indicates the number of 428 intermediate nodes remaining. That is, number of explicitly 429 listed intermediate nodes still to be visited before reaching the 430 destination node in the forward path. The Node Left field is set 431 to n-1, where n is the number of intermediate nodes. 433 o Counter Tuple list [1..n]: A variable-length field, which record 434 the Receive Counter and the Transmit Counter when the data packet 435 is received at and transmitted by the n-th intermediate node. The 436 Counter Tuple list is encoded starting from the last intermediate 437 node which is explicitly listed. That is, the first element of 438 the Counter Tuple list [1] records the Receive Counter and the 439 Transmit Counter when the data packet is received at and 440 transmitted by the last intermediate node of a explicit path, the 441 second element records the penultimate Counter Tuple when the data 442 packet received and forwarded at the penultimate intermediate node 443 of a explicit path, and so on. 445 The STAMP Session-Sender generates the STAMP test packet with the HbH 446 Direct Loss TLV. When an intermediate node receives the STAMP test 447 packet, the node punts the packet to control plane and writes the 448 Receive Counter [n] and the Transmit Counter [n] at the Counter Tuple 449 list [n] in the Session-Sender test packet. The mechanism of punting 450 packet to control plane is outside the scope of this specification. 452 When the STAMP Session-Reflector received the test packet with the 453 HbH Direct Loss TLV, it MUST copy the HbH Direct Loss TLV into the 454 Session-Reflector test packet before its transmission. Using HbH 455 Direct Loss TLV in STAMP testing enables packet loss measurement per 456 node/link in the forward path. 458 3.5. HbH Bandwidth Utilization TLV 460 STAMP Session-Sender MAY place the HbH Bandwidth Utilization (BW 461 Utilization) TLV in Session-Sender test packets to record the ingress 462 and egress BW Utilization at every intermediate nodes along the 463 forward path. The Session-Sender MUST set the Length value according 464 to the number of explicitly listed intermediate nodes in the forward 465 path. A BW Utilization Tuple is composed of a 32-bit ingress BW 466 Utilization field and a 32-bit egress BW Utilization field. The BW 467 Utilization Tuple list [1..n] fields MUST be set to zero upon 468 Session-Sender test packets transmission. 470 The HbH Bandwidth Utilization TLV has the following format: 472 0 1 2 3 473 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 1 474 +-------------------------------+---------------+---------------+ 475 | HbH BW Utilization Type | Length | Node Left | 476 +-------------------------------+---------------+---------------+ 477 | BW Utilization Tuple list [1] | 478 | | 479 +---------------------------------------------------------------+ 480 ~ ... ~ 481 +---------------------------------------------------------------+ 482 | BW Utilization Tuple list [n] | 483 | | 484 +---------------------------------------------------------------+ 486 Fig. 6 HbH Bandwidth Utilization TLV Format 488 where fields are defined as the following: 490 o HbH BW Utilization Type: To be assigned by IANA. 492 o Length: A 8-bit field that indicates the length of the value 493 portion in octets and will be a multiple of 8 octets dependent on 494 the number of explicitly listed intermediate nodes in the forward 495 path. 497 o Node Left: A 8-bit unsigned integer, which indicates the number of 498 intermediate nodes remaining. That is, number of explicitly 499 listed intermediate nodes still to be visited before reaching the 500 destination node in the forward path. The Node Left field is set 501 to n-1, where n is the number of intermediate nodes. 503 o BW Utilization Tuple list [1..n]: A variable-length field, which 504 record the ingress and egress bandwidth utilization when the test 505 packet is received at and transmitted by the n-th intermediate 506 node. The BW Utilization Tuple list is encoded starting from the 507 last intermediate node which is explicitly listed. That is, the 508 first element of the BW Utilization Tuple list [1] records the 509 ingress and the egress bandwidth utilization when the test packet 510 is received at and transmitted by the last intermediate node of a 511 explicit path, the second element records the penultimate BW 512 Utilization Tuple when the test packet received at and transmitted 513 by the penultimate intermediate node of a explicit path, and so 514 on. 516 The STAMP Session-Sender generates the STAMP test packet with the HbH 517 BW Utilization TLV. When an intermediate node receives the STAMP 518 test packet, the node punts the packet to control plane and writes 519 the ingress and egress bandwidth utilization at the BW Utilization 520 Tuple list [n] in the Session-Sender test packet. The mechanism of 521 punting packet to control plane is outside the scope of this 522 specification. 524 When the STAMP Session-Reflector received the test packet with the 525 HbH BW Utilization TLV, it MUST copy the HbH BW Utilization TLV into 526 the Session-Reflector test packet before its transmission. The HbH 527 BW Utilization TLV carried in STAMP test packet is usable to detect 528 and troubleshoot the link congestion in the forward path. 530 3.6. HbH Timestamp Information TLV 532 STAMP Session-Sender MAY place the HbH Timestamp Information TLV in 533 Session-Sender test packets to record the ingress and egress 534 Timestamp Information at every intermediate nodes along the forward 535 path. The Timestamp Information includes the source of clock 536 synchronization and the method of timestamp obtainment. There are 537 several types of clock synchronization source, e.g., NTP, PTP. The 538 method of timestamp obtainment may be from control plane (e.g. NTP) 539 or from data plane (e.g. PTP). 541 A Timestamp Info Tuple is composed of a 8-bit ingress clock source 542 field, a 8-bit ingress timestamp obtainment field, a 8-bit egress 543 clock source field, and a 8-bit egress timestamp obtainment field. 544 The Session-Sender MUST set the Length value according to the number 545 of explicitly listed intermediate nodes in the forward path. The 546 Timestamp Info Tuple list [1..n] fields MUST be set to zero upon 547 Session-Sender test packets transmission. 549 The HbH Timestamp Information TLV has the following format: 551 0 1 2 3 552 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 1 553 +-------------------------------+---------------+---------------+ 554 | HbH Timestamp Info Type | Length | Node Left | 555 +-------------------------------+---------------+---------------+ 556 | Timestamp Info Tuple list [1] | 557 +---------------------------------------------------------------+ 558 ~ ... ~ 559 +---------------------------------------------------------------+ 560 | Timestamp Info Tuple list [n] | 561 +---------------------------------------------------------------+ 563 Fig. 6 HbH Timestamp Information TLV Format 565 where fields are defined as the following: 567 o HbH Timestamp Info Type: To be assigned by IANA. 569 o Length: A 8-bit field that indicates the length of the value 570 portion in octets and will be a multiple of 4 octets dependent on 571 the number of explicitly listed intermediate nodes in the forward 572 path. 574 o Node Left: A 8-bit unsigned integer, which indicates the number of 575 intermediate nodes remaining. That is, number of explicitly 576 listed intermediate nodes still to be visited before reaching the 577 destination node in the forward path. The Node Left field is set 578 to n-1, where n is the number of intermediate nodes. 580 o Timestamp Info Tuple list [1..n]: A variable-length field, which 581 record the source of clock synchronization and the method of 582 timestamp obtainment at the ingress and egress when the test 583 packet is received at and transmitted by the n-th intermediate 584 node. The Timestamp Info Tuple list is encoded starting from the 585 last intermediate node which is explicitly listed. That is, the 586 first element of the Timestamp Info Tuple list [1] records the 587 source of clock synchronization and the method of timestamp 588 obtainment at the ingress and egress when the test packet is 589 received at and transmitted by the last intermediate node of a 590 explicit path, the second element records the penultimate 591 Timestamp Info Tuple when the test packet received at and 592 transmitted by the penultimate intermediate node of a explicit 593 path, and so on. 595 The STAMP Session-Sender generates the STAMP test packet with the HbH 596 Timestamp Information TLV. When an intermediate node receives the 597 STAMP test packet, the node punts the packet to control plane and 598 writes the source of clock synchronization and the method of 599 timestamp obtainment at the Timestamp Info Tuple list [n] in the 600 Session-Sender test packet. The mechanism of punting packet to 601 control plane is outside the scope of this specification. 603 When the STAMP Session-Reflector received the test packet with the 604 HbH Timestamp Information TLV, it MUST copy the HbH Timestamp 605 Information TLV into the Session-Reflector test packet before its 606 transmission. The HbH Timestamp Information TLV carried in STAMP 607 test packet is usable to query timestamp information from every nodes 608 in the forward path. 610 Note that the source of clock synchronization, NTP or PTP, is part of 611 configuration of the Session-Sender/Reflector or a particular test 612 session [RFC8762]. This draft recommends every intermediate nodes to 613 be configured to use the same source of clock synchronization. 615 3.7. HbH Interface Errors TLV 617 STAMP Session-Sender MAY place the HbH Interface Errors TLV in 618 Session-Sender test packets to record the errors detected on the 619 interface of every intermediate node used to receive the packet along 620 the forward path. The record of interface errors indicates the 621 quality of the interfaces along the forward path and is helpful to 622 analyze the performance degrades associated with the flow. 624 A Interface Errors is a 32 bits unsigned integer field. This field 625 records the Bit Error Rate (BER) or number of packet drop due to 626 Cyclic Redundancy Check (CRC) errors. The Session-Sender MUST set 627 the Length value according to the number of explicitly listed 628 intermediate nodes in the forward path. The Interface Errors list 629 [1..n] fields MUST be set to zero upon Session-Sender test packets 630 transmission. 632 The HbH Timestamp Information TLV has the following format: 634 0 1 2 3 635 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 1 636 +-------------------------------+---------------+---------------+ 637 | HbH Interface Errors Type | Length | Node Left | 638 +-------------------------------+---------------+---------------+ 639 | Interface Errors list [1] | 640 +---------------------------------------------------------------+ 641 ~ ... ~ 642 +---------------------------------------------------------------+ 643 | Interface Errors list [n] | 644 +---------------------------------------------------------------+ 646 Fig. 6 HbH Timestamp Information TLV Format 648 where fields are defined as the following: 650 o HbH Interface Errors Type: To be assigned by IANA. 652 o Length: A 8-bit field that indicates the length of the value 653 portion in octets and will be a multiple of 4 octets dependent on 654 the number of explicitly listed intermediate nodes in the forward 655 path. 657 o Node Left: A 8-bit unsigned integer, which indicates the number of 658 intermediate nodes remaining. That is, number of explicitly 659 listed intermediate nodes still to be visited before reaching the 660 destination node in the forward path. The Node Left field is set 661 to n-1, where n is the number of intermediate nodes. 663 o Interface Errors list [1..n]: A variable-length field, which 664 record the errors detected on the interface of the n-th 665 intermediate node used to receive the packet along the forward 666 path. The Interface Errors list is encoded starting from the last 667 intermediate node which is explicitly listed. That is, the first 668 element of the Interface Errors list [1] records the interface 669 errors when the test packet is received at the last intermediate 670 node of a explicit path, the second element records the 671 penultimate interface errors when the test packet received at the 672 penultimate intermediate node of a explicit path, and so on. 674 The STAMP Session-Sender generates the STAMP test packet with the HbH 675 Interface Errors TLV. When an intermediate node receives the STAMP 676 test packet, the node punts the packet to control plane and writes 677 the errors at the Interface Errors list [n] in the Session-Sender 678 test packet. The mechanism of punting packet to control plane is 679 outside the scope of this specification. 681 When the STAMP Session-Reflector received the test packet with the 682 HbH Interface Errors TLV, it MUST copy the HbH Interface Errors TLV 683 into the Session-Reflector test packet before its transmission. The 684 HbH Interface Errors TLV carried in STAMP test packet is usable to 685 detect interface errors from every intermediate nodes along the 686 forward path. 688 4. IANA Considerations 690 IANA is requested to allocate values for the following TLV Type from 691 the "STAMP TLV Type" registry [RFC8972]. 693 +------------+-------------------------------+---------------+ 694 | Code Point | Description | Reference | 695 +------------+-------------------------------+---------------+ 696 | TBA1 | IOAM Tracing Data TLV | This document | 697 | TBA2 | Forward HbH Delay TLV | This document | 698 | TBA3 | Backward HbH Delay TLV | This document | 699 | TBA4 | HbH Direct Loss TLV | This document | 700 | TBA5 | HbH BW Utilization TLV | This document | 701 | TBA6 | HbH Timestamp Information TLV | This document | 702 | TBA7 | HbH Interface Errors TLV | This document | 703 +------------+-------------------------------+---------------+ 705 5. Security Considerations 707 This document extensions new optional TLVs to STAMP. It does not 708 introduce any new security risks to STAMP. 710 6. Acknowledgements 712 The authors would like to thank Giuseppe Fioccola for the reviews and 713 comments. 715 7. References 717 7.1. Normative References 719 [I-D.ietf-ippm-ioam-data] 720 "Data Fields for In-situ OAM", 721 . 724 [I-D.ietf-ippm-ioam-ipv6-options] 725 "In-situ OAM IPv6 Options", 726 . 729 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 730 Requirement Levels", BCP 14, RFC 2119, 731 DOI 10.17487/RFC2119, March 1997, 732 . 734 [RFC8762] "Simple Two-Way Active Measurement Protocol", 735 . 737 [RFC8972] "Simple Two-way Active Measurement Protocol Optional 738 Extensions", . 740 7.2. Informative References 742 [IEEE.1588.2008] 743 "IEEE Standard for a Precision Clock Synchronization 744 Protocol for Networked Measurement and Control Systems", 745 . 747 [RFC5905] "Network Time Protocol Version 4: Protocol and Algorithms 748 Specification", . 750 Authors' Addresses 752 Yali Wang 753 Huawei 754 156 Beijing Rd., Haidian District 755 Beijing 756 China 758 Email: wangyali11@huawei.com 760 Tianran Zhou 761 Huawei 762 156 Beijing Rd., Haidian District 763 Beijing 764 China 766 Email: zhoutianran@huawei.com 768 Hongwei Yang 769 China Mobile 770 Xibianmen Inner St, 53, Xicheng District 771 Beijing 772 China 774 Email: yanghongwei@chinamobile.com 775 Chang Liu 776 China Unicom 777 Beijing 778 China 780 Email: liuc131@chinaunicom.cn