idnits 2.17.1 draft-ietf-manet-dlep-traffic-classification-06.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 (29 July 2021) is 994 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(See RFCs 3967 and 4897 for information about using normative references to lower-maturity documents in RFCs) == Outdated reference: A later version (-13) exists of draft-ietf-manet-dlep-credit-flow-control-08 == Outdated reference: A later version (-16) exists of draft-ietf-manet-dlep-da-credit-extension-11 Summary: 0 errors (**), 0 flaws (~~), 3 warnings (==), 1 comment (--). Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 2 Network Working Group B. Cheng 3 Internet-Draft D. Wiggins 4 Intended status: Standards Track MIT Lincoln Laboratory 5 Expires: 30 January 2022 L. Berger 6 LabN Consulting, L.L.C. 7 29 July 2021 9 DLEP Traffic Classification Data Item 10 draft-ietf-manet-dlep-traffic-classification-06 12 Abstract 14 This document defines a new Dynamic Link Exchange Protocol (DLEP) 15 Data Item that is used to support traffic classification. Traffic 16 classification information is used to identify traffic flows based on 17 frame/packet content such as destination address. The Data Item is 18 defined in an extensible and reusable fashion. Its use will be 19 mandated in other documents defining specific DLEP extensions. This 20 document also introduces DLEP Sub-Data Items, and Sub-Data Items are 21 defined to support DiffServ and Ethernet traffic classification. 23 Status of This Memo 25 This Internet-Draft is submitted in full conformance with the 26 provisions of BCP 78 and BCP 79. 28 Internet-Drafts are working documents of the Internet Engineering 29 Task Force (IETF). Note that other groups may also distribute 30 working documents as Internet-Drafts. The list of current Internet- 31 Drafts is at https://datatracker.ietf.org/drafts/current/. 33 Internet-Drafts are draft documents valid for a maximum of six months 34 and may be updated, replaced, or obsoleted by other documents at any 35 time. It is inappropriate to use Internet-Drafts as reference 36 material or to cite them other than as "work in progress." 38 This Internet-Draft will expire on 30 January 2022. 40 Copyright Notice 42 Copyright (c) 2021 IETF Trust and the persons identified as the 43 document authors. All rights reserved. 45 This document is subject to BCP 78 and the IETF Trust's Legal 46 Provisions Relating to IETF Documents (https://trustee.ietf.org/ 47 license-info) in effect on the date of publication of this document. 48 Please review these documents carefully, as they describe your rights 49 and restrictions with respect to this document. Code Components 50 extracted from this document must include Simplified BSD License text 51 as described in Section 4.e of the Trust Legal Provisions and are 52 provided without warranty as described in the Simplified BSD License. 54 Table of Contents 56 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 57 1.1. Key Words . . . . . . . . . . . . . . . . . . . . . . . . 3 58 2. Traffic Classification . . . . . . . . . . . . . . . . . . . 3 59 2.1. Traffic Classification Data Item . . . . . . . . . . . . 4 60 2.1.1. Traffic Classification Sub-Data Item . . . . . . . . 6 61 2.2. DiffServ Traffic Classification Sub-Data Item . . . . . . 7 62 2.2.1. Router Receive Processing . . . . . . . . . . . . . . 8 63 2.3. Ethernet Traffic Classification Sub-Data Item . . . . . . 8 64 2.3.1. Router Receive Processing . . . . . . . . . . . . . . 10 65 3. Compatibility . . . . . . . . . . . . . . . . . . . . . . . . 10 66 4. Security Considerations . . . . . . . . . . . . . . . . . . . 10 67 5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 10 68 5.1. Data Item Values . . . . . . . . . . . . . . . . . . . . 10 69 5.2. DLEP Traffic Classification Sub-Data Item Registry . . . 11 70 6. References . . . . . . . . . . . . . . . . . . . . . . . . . 11 71 6.1. Normative References . . . . . . . . . . . . . . . . . . 11 72 6.2. Informative References . . . . . . . . . . . . . . . . . 11 73 Appendix A. Acknowledgments . . . . . . . . . . . . . . . . . . 13 74 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 13 76 1. Introduction 78 The Dynamic Link Exchange Protocol (DLEP) is defined in [RFC8175]. 79 It provides the exchange of link related control information between 80 DLEP peers. DLEP peers are comprised of a modem and a router. DLEP 81 defines a base set of mechanisms as well as support for possible 82 extensions. DLEP defines Data Items which are sets of information 83 that can be reused in DLEP messaging. The base DLEP specification 84 does not include any flow identification beyond DLEP endpoints. This 85 document defines DLEP Data Item formats which provide flow 86 identification on a more granular basis. Specifically it enables a 87 router to use traffic flow classification information provided by the 88 modem to identify traffic flows. In this case, a flow is identified 89 based on information found in a data plane header and one or more 90 matches are associated with a single flow. (For general background 91 on traffic classification see [RFC2475] Section 2.3.) The Data Item 92 is structured to allow for use of the defined traffic classification 93 information with applications such as credit window control as 94 specified in [I-D.ietf-manet-dlep-da-credit-extension] 95 This document defines traffic classification based on a DLEP 96 destination and flows identified by either DiffServ [RFC2475] DSCPs 97 (differentiated services codepoints) or IEEE 802.1Q 98 [IEEE.802.1Q_2014] Ethernet Priority Code Points (PCP). The defined 99 mechanism allows for flows to be described in a flexible fashion and 100 when combined with applications such as credit window control, allows 101 credit windows to be shared across traffic sent to multiple DLEP 102 destinations and as part of multiple flows, or used exclusively for 103 traffic sent to a particular destination and/or belonging to a 104 particular flow. The extension also supports the "wildcard" matching 105 of any flow (DSCP or PCP). Traffic classification information is 106 provided such that it can be readily extended to support other 107 traffic classification techniques, or be used by non-credit window 108 related extensions, such as [RFC8651] or even 5-tuple IP flows. 110 This document defines support for traffic classification using a 111 single new Data Item in Section 2.1 for general support and two new 112 Sub-Data Items are defined to support identification of flows based 113 on DSCPs and PCPs. 115 1.1. Key Words 117 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 118 "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and 119 "OPTIONAL" in this document are to be interpreted as described in BCP 120 14 [RFC2119] [RFC8174] when, and only when, they appear in all 121 capitals, as shown here. 123 2. Traffic Classification 125 The Traffic Classification Data Item is used to represent a list of 126 flows that may be used at the same time for traffic sent from a 127 router to a modem. The data plane information used to identify each 128 flow is represented in a separate Sub-Data Item. The Data Item and 129 Sub-Data Item structure is intended to be independent of any specific 130 usage of the flow identification, e.g., flow control. The Sub-Data 131 Item structure is also intended to allow for future traffic 132 classification types, e.g., 5-tuple flows. While the structure of 133 the Data Items is extensible, actual flow information is expected to 134 be used in an extension dependent manner. Support for DSCP and PCP- 135 based flows are defined via individual Sub-Data Items below. Other 136 types of flow identification, e.g., based on IP protocol and ports, 137 may be defined in the future via new Sub-Data Items. Note that when 138 extensions supporting multiple Sub-Data Item types are negotiated, 139 these types MAY be combined in a single Data Item. 141 Each list of flows is identified using a "Traffic Classification 142 Identifier" or "TID" and is expected to represent a valid combination 143 of data plane identifiers that may be used at the same time. Each 144 flow is identified via a "Flow Identifier" or "FID". Each FID is 145 defined in a Sub-Data Item which carries the data plane identifier or 146 identifiers used to associate traffic with the flow. A DLEP 147 destination address is also needed to complete traffic classification 148 information used in extensions such as flow control. This 149 information is expected to be provided in an extension specific 150 manner. For example, this address can be provided by a modem when it 151 identifies the traffic classification set in a Destination Up Message 152 using the Credit Window Associate Data Item defined in 153 [I-D.ietf-manet-dlep-credit-flow-control]. TID and FID values is a 154 modem-local scope. 156 2.1. Traffic Classification Data Item 158 This sections defines the Traffic Classification Data Item. This 159 Data Item is used by a modem to provide a router with traffic 160 classification information. When an extension requires use of this 161 Data Item the Traffic Classification Data Item SHOULD be included by 162 a modem in any Session Initialization Response Message, e.g., see 163 [I-D.ietf-manet-dlep-da-credit-extension]. Updates to previously 164 provided traffic classifications or new traffic classifications MAY 165 be sent by a modem by including the Data Item in Session Update 166 Messages. More than one Data Item MAY be included in a message to 167 provide information on multiple traffic classifiers. 169 The set of traffic classification information provided in the data 170 item is identified using a Traffic Classification Identifier, or TID. 171 The actual data plane related information used in traffic 172 classification is provided in a variable list of Traffic 173 Classification Sub-Data Items. 175 The format of the Traffic Classification Data Item is: 177 0 1 2 3 178 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 1 179 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 180 | Data Item Type | Length | 181 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 182 |Traffic Class. Identifier (TID)| Num SDIs | Reserved | 183 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 184 | Traffic Classification Sub-Data Item 1 | 185 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 186 : ... : 187 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 188 | Traffic Classification Sub-Data Item n | 189 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 191 Data Item Type: 192 TBA1 194 Length: 195 Variable 197 Per [RFC8175] Length is the number of octets in the Data Item, 198 excluding the Type and Length fields. 200 Traffic Classification Identifier (TID): 201 A 16-bit unsigned integer identifying a traffic classification 202 set. There is no restriction on values used by a modem, and there 203 is no requirement for sequential or ordered values. 205 Num SDIs: 206 An 8-bit unsigned integer indicating the number of Traffic 207 Classification Sub-Data Items included in the Data Item. A value 208 of zero (0) is allowed and indicates that no traffic should be 209 matched against this TID. 211 Reserved: 212 MUST be set to zero by the sender (a modem) and ignored by the 213 receiver (a router). 215 Traffic Classification Sub-Data Item: 216 Zero or more Traffic Classification Sub-Data Items of the format 217 defined below MAY be included. The number MUST match the value 218 carried in the Num SDIs field. 220 A router receiving the Traffic Classification Data Item MUST locate 221 the traffic classification information that is associated with the 222 TID indicated in each received Data Item. If no associated traffic 223 classification information is found, the router MUST initialize a new 224 information set using the values carried in the Data Item. When 225 associated traffic classification information is found, the router 226 MUST update the information using the values carried in the Data 227 Item. In both cases, a router MUST also ensure that any data plane 228 state, e.g., [I-D.ietf-manet-dlep-credit-flow-control], that is 229 associated with the TID is updated as needed. 231 2.1.1. Traffic Classification Sub-Data Item 233 All Traffic Classification Sub-Data Items share a common format that 234 is patterned after the standard DLEP Data Item format, see [RFC8175] 235 Section 11.3. There is no requirement on, or meaning to Sub-Data 236 Item ordering. Any errors or inconsistencies encountered in parsing 237 Sub-Data Items are handled in the same fashion as any other Data Item 238 parsing error encountered in DLEP. 240 The format of the Traffic Classification Sub-Data Item is: 242 0 1 2 3 243 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 1 244 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 245 | Sub-Data Item Type | Length | 246 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 247 | Value... : 248 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 250 Sub-Data Item Type: 251 A 16-bit unsigned integer that indicates the type and 252 corresponding format of the Sub-Data Item's Value field. Sub-Data 253 Item Types are scoped within the Data Item in which they are 254 carried, i.e., the Sub-Data Item Type field MUST be used together 255 with the Traffic Classification Data Item Type to identify the 256 format of the Sub-Data Item. Traffic Classification Sub-Data Item 257 Types are managed according to the IANA registry described in 258 Section 5.2. 260 Length: 261 Variable 263 Copying [RFC8175], Length is a 16-bit unsigned integer that is the 264 number of octets in the Sub-Data Item, excluding the Type and 265 Length fields. 267 2.2. DiffServ Traffic Classification Sub-Data Item 269 The DiffServ Traffic Classification Sub-Data Item is used to identify 270 the set of DSCPs that should be treated as a single flow, i.e., 271 receive the same traffic treatment. DSCPs are identified in a list 272 of DiffServ fields. An implementation that does not support DSCPs 273 and wants the same traffic treatment for all traffic to a destination 274 or destinations would indicate 0 DSCPs. 276 The format of the DiffServ Traffic Classification Sub-Data Item is: 278 0 1 2 3 279 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 1 280 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 281 | Must be one (1) | Length | 282 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 283 | Flow Identifier (FID) | Num DSCPs | DS Field 1 | 284 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 285 | DS Field 2 | ... | DS Field n | 286 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 288 Length: 289 Variable 291 Length is defined above. For this Sub-Data Item, it is equal to 292 three (3) plus the value of the Num DSCPs field. 294 Flow Identifier (FID): 295 A 16-bit unsigned integer representing the data plane information 296 carried in the Sub-Data Item that is to be used in identifying a 297 flow. The value of 0xFFFF is reserved and MUST NOT be used in 298 this field. 300 Num DSCPs: 301 An 8-bit unsigned integer indicating the number of DSCPs carried 302 in the Sub-Data Item. A zero (0) indicates a (wildcard) match 303 against any DSCP value. 305 DS Field: 306 Each DS Field is an 8-bit whose definition is the same as 307 [RFC2474]. 309 0 1 2 3 4 5 6 7 310 +---+---+---+---+---+---+---+---+ 311 | DSCP | CU | 312 +---+---+---+---+---+---+---+---+ 314 DSCP: differentiated services codepoint 315 CU: currently unused, MUST be zero 317 2.2.1. Router Receive Processing 319 A router receiving the Traffic Classification Sub-Data Item MUST 320 validate the information on receipt, prior to using the carried 321 information, including potentially updating the data behavior as 322 determined by the extension requiring the use of the Sub-Data Item. 323 Validation failures MUST be treated as an error as described above. 325 Once validated, the receiver MUST ensure that each DS Field value is 326 listed only once across the whole Traffic Classification Data Item. 327 Note, this check is across the Data Item and not the individual Sub- 328 Data Item. If the same DS Field value is listed more than once 329 within the same Traffic Classification Data Item, the Data Item MUST 330 be treated as an error as described above. 332 2.3. Ethernet Traffic Classification Sub-Data Item 334 The Ethernet Traffic Classification Sub-Data Item is used to identify 335 the VLAN and PCPs that should be treated as a single flow, i.e., 336 receive the same traffic treatment. Ethernet Priority Code Point 337 support is defined as part of the IEEE 802.1Q [IEEE.802.1Q_2014] tag 338 format and includes a 3 bit "PCP" field. The tag format also 339 includes a 12 bit VLAN identifier (VID) field. PCPs are identified 340 in a list of priority fields. An implementation that does not 341 support PCPs and wants the same traffic treatment for all traffic to 342 a destination or destinations would indicate 0 PCPs. Such an 343 implementation could identify a VLAN to use per destination. 345 The format of the Ethernet Traffic Classification Sub-Data Item is: 347 0 1 2 3 348 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 1 349 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 350 | Must be two (2) | Length | 351 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 352 | Flow Identifier (FID) |NumPCPs| VLAN Identifier (VID) | 353 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 354 | Pri. 1| Pri. 2| ..... | ..... | ..... | Pad | 355 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 357 Length: 358 Variable 360 Length is defined above. For this Sub-Data Item, it is equal to 361 four (4) plus the number of octets needed to accommodate the 362 number of Priority fields indicated by the NumPCPs field. Note 363 that as length is in octets and each Priority field is 4 bits, the 364 additional length is the value carried in the NumPCPs field 365 divided by two and rounded up to the next higher integer quantity. 367 Flow Identifier (FID): 368 A 16-bit unsigned integer representing the data plane information 369 carried in the Sub-Data Item that is to be used in identifying a 370 flow. The value of 0xFFFF is reserved and MUST NOT be used in 371 this field. 373 Num PCPs: 374 A 4-bit unsigned integer indicating the number of Priority fields 375 carried in the Sub-Data Item. A zero (0) indicates a (wildcard) 376 match against any PCP value. 378 VLAN identifier (VID): 379 A 12-bit unsigned integer field indicating the VLAN to be used in 380 traffic classification. A value of zero (0) indicates that the 381 VID is to be ignored and any VID is to be accepted during traffic 382 classification. 384 Priority: 385 Each Priority Field is 4-bits long and indicates a PCP field 386 defined in [IEEE.802.1Q_2014]. Note that zero (0) is a valid 387 value for either PCP or DEI. 389 0 1 2 3 390 +---+---+---+---+ 391 | PCP |DEI| 392 +---+---+---+---+ 394 PCP: Priority code point 395 DEI: currently unused, MUST be zero 397 Pad: 398 A 4-bit long field included when NumPCPs is an odd number. This 399 field MUST be set to zero by the sender, and MUST be ignored on 400 receipt. 402 2.3.1. Router Receive Processing 404 A router receiving the Traffic Classification Sub-Data Item MUST 405 validate the information on receipt, prior to the using the carried 406 information, including potentially updating the data behavior as 407 determined by the extension requiring the use of the Sub-Data Item. 408 Validation failures MUST be treated as an error as described above. 410 Once validated, the receiver MUST ensure that each Priority Field 411 value is listed only once across the whole Traffic Classification 412 Data Item. Note, this check is across the Data Item and not the 413 individual Sub-Data Item. If the same Priority Field value is listed 414 more than once within the same Traffic Classification Data Item, the 415 Data Item MUST be treated as an error as described above. 417 3. Compatibility 419 The formats defined in this document will only be used when 420 extensions require their use. 422 4. Security Considerations 424 This document introduces finer grain flow identification mechanisms 425 to DLEP. These mechanisms do not inherently introduce any additional 426 vulnerabilities above those documented in [RFC8175]. The approach 427 taken to Security in that document applies equally to the mechanism 428 defined in this document. 430 5. IANA Considerations 432 This document requests the assignment of several values by IANA. All 433 assignments are to registries defined by [RFC8175]. 435 5.1. Data Item Values 437 This document requests the following new assignments to the DLEP Data 438 Item Registry named "Data Item Type Values" in the range with the 439 "Specification Required" policy. The requested values are as 440 follows: 442 +===========+========================+ 443 | Type Code | Description | 444 +===========+========================+ 445 | TBA1 | Traffic Classification | 446 +-----------+------------------------+ 448 Table 1: Requested Data Item Values 450 5.2. DLEP Traffic Classification Sub-Data Item Registry 452 Upon approval of this document, IANA is requested to create a new 453 DLEP registry, named "Traffic Classification Sub-Data Item Type 454 Values". 456 The following table provides initial registry values and the 457 [RFC8126] defined policies that should apply to the registry: 459 +=============+=================================+ 460 | Type Code | Description | 461 +=============+=================================+ 462 | 0 | Reserved | 463 +-------------+---------------------------------+ 464 | 1 | DiffServ Traffic Classification | 465 +-------------+---------------------------------+ 466 | 2 | Ethernet Traffic Classification | 467 +-------------+---------------------------------+ 468 | 3-65407 | Specification Required | 469 +-------------+---------------------------------+ 470 | 65408-65534 | Private Use | 471 +-------------+---------------------------------+ 472 | 65535 | Reserved | 473 +-------------+---------------------------------+ 475 Table 2: Initial Registry Values 477 6. References 479 6.1. Normative References 481 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 482 Requirement Levels", BCP 14, RFC 2119, 483 DOI 10.17487/RFC2119, March 1997, 484 . 486 [RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 487 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, 488 May 2017, . 490 [RFC8175] Ratliff, S., Jury, S., Satterwhite, D., Taylor, R., and B. 491 Berry, "Dynamic Link Exchange Protocol (DLEP)", RFC 8175, 492 DOI 10.17487/RFC8175, June 2017, 493 . 495 6.2. Informative References 497 [I-D.ietf-manet-dlep-credit-flow-control] 498 Cheng, B., Wiggins, D., Berger, L., and S. Ratliff, "DLEP 499 Credit-Based Flow Control Messages and Data Items", Work 500 in Progress, Internet-Draft, draft-ietf-manet-dlep-credit- 501 flow-control-08, 21 June 2021, 502 . 505 [I-D.ietf-manet-dlep-da-credit-extension] 506 Cheng, B., Wiggins, D., and L. Berger, "DLEP DiffServ 507 Aware Credit Window Extension", Work in Progress, 508 Internet-Draft, draft-ietf-manet-dlep-da-credit-extension- 509 11, 21 June 2021, . 512 [IEEE.802.1Q_2014] 513 IEEE, "IEEE Standard for Local and metropolitan area 514 networks--Bridges and Bridged Networks", IEEE 802.1Q-2014, 515 DOI 10.1109/ieeestd.2014.6991462, 18 December 2014, 516 . 519 [RFC2474] Nichols, K., Blake, S., Baker, F., and D. Black, 520 "Definition of the Differentiated Services Field (DS 521 Field) in the IPv4 and IPv6 Headers", RFC 2474, 522 DOI 10.17487/RFC2474, December 1998, 523 . 525 [RFC2475] Blake, S., Black, D., Carlson, M., Davies, E., Wang, Z., 526 and W. Weiss, "An Architecture for Differentiated 527 Services", RFC 2475, DOI 10.17487/RFC2475, December 1998, 528 . 530 [RFC8126] Cotton, M., Leiba, B., and T. Narten, "Guidelines for 531 Writing an IANA Considerations Section in RFCs", BCP 26, 532 RFC 8126, DOI 10.17487/RFC8126, June 2017, 533 . 535 [RFC8651] Cheng, B., Wiggins, D., and L. Berger, Ed., "Dynamic Link 536 Exchange Protocol (DLEP) Control-Plane-Based Pause 537 Extension", RFC 8651, DOI 10.17487/RFC8651, October 2019, 538 . 540 Appendix A. Acknowledgments 542 The Sub-Data Item format was inspired by Rick Taylor's "Data Item 543 Containers". He also proposed the separation of credit windows from 544 traffic classification at IETF98. Many useful comments were received 545 from contributors to the MANET working group. This document was 546 derived from [I-D.ietf-manet-dlep-da-credit-extension] as a result of 547 discussions at IETF101. Many useful comments were received from 548 contributors to the MANET working group, notably Ronald in't Velt. 550 Authors' Addresses 552 Bow-Nan Cheng 553 MIT Lincoln Laboratory 554 Massachusetts Institute of Technology 555 244 Wood Street 556 Lexington 558 Email: bcheng@ll.mit.edu 560 David Wiggins 561 MIT Lincoln Laboratory 562 Massachusetts Institute of Technology 563 244 Wood Street 564 Lexington 566 Email: David.Wiggins@ll.mit.edu 568 Lou Berger 569 LabN Consulting, L.L.C. 571 Email: lberger@labn.net