idnits 2.17.1 draft-ietf-manet-dlep-da-credit-extension-00.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 9, 2017) is 2630 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(See RFCs 3967 and 4897 for information about using normative references to lower-maturity documents in RFCs) == Outdated reference: A later version (-29) exists of draft-ietf-manet-dlep-24 == Outdated reference: A later version (-07) exists of draft-ietf-manet-credit-window-04 Summary: 0 errors (**), 0 flaws (~~), 3 warnings (==), 1 comment (--).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 Lincoln Laboratory 5 Expires: August 13, 2017 L. Berger 6 LabN Consulting, L.L.C. 7 February 9, 2017 9 DLEP DiffServ Aware Credit Windowing Extension 10 draft-ietf-manet-dlep-da-credit-extension-00 12 Abstract 14 This document defines an extension to the DLEP protocol that enables 15 a DiffServ aware credit-windowing scheme for destination-specific 16 flow control. 18 Status of This Memo 20 This Internet-Draft is submitted in full conformance with the 21 provisions of BCP 78 and BCP 79. 23 Internet-Drafts are working documents of the Internet Engineering 24 Task Force (IETF). Note that other groups may also distribute 25 working documents as Internet-Drafts. The list of current Internet- 26 Drafts is at http://datatracker.ietf.org/drafts/current/. 28 Internet-Drafts are draft documents valid for a maximum of six months 29 and may be updated, replaced, or obsoleted by other documents at any 30 time. It is inappropriate to use Internet-Drafts as reference 31 material or to cite them other than as "work in progress." 33 This Internet-Draft will expire on August 13, 2017. 35 Copyright Notice 37 Copyright (c) 2017 IETF Trust and the persons identified as the 38 document authors. All rights reserved. 40 This document is subject to BCP 78 and the IETF Trust's Legal 41 Provisions Relating to IETF Documents 42 (http://trustee.ietf.org/license-info) in effect on the date of 43 publication of this document. Please review these documents 44 carefully, as they describe your rights and restrictions with respect 45 to this document. Code Components extracted from this document must 46 include Simplified BSD License text as described in Section 4.e of 47 the Trust Legal Provisions and are provided without warranty as 48 described in the Simplified BSD License. 50 Table of Contents 52 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 53 1.1. Key Words . . . . . . . . . . . . . . . . . . . . . . . . 3 54 2. Extension Overview . . . . . . . . . . . . . . . . . . . . . 3 55 3. Extension Usage and Identification . . . . . . . . . . . . . 4 56 4. Extension Messages . . . . . . . . . . . . . . . . . . . . . 4 57 4.1. Credit Control Message . . . . . . . . . . . . . . . . . 4 58 4.2. Credit Control Response Message . . . . . . . . . . . . . 5 59 5. Extension Data Items . . . . . . . . . . . . . . . . . . . . 5 60 5.1. Queue Parameters . . . . . . . . . . . . . . . . . . . . 5 61 5.2. DiffServ Aware (DA) Credit Grant . . . . . . . . . . . . 8 62 5.3. DiffServ Aware (DA) Credit Window Status . . . . . . . . 10 63 5.4. DiffServ Aware (DA) Credit Request . . . . . . . . . . . 11 64 6. Compatibility . . . . . . . . . . . . . . . . . . . . . . . . 12 65 7. Security Considerations . . . . . . . . . . . . . . . . . . . 13 66 8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 13 67 8.1. Extension Type Value . . . . . . . . . . . . . . . . . . 13 68 8.2. Message Values . . . . . . . . . . . . . . . . . . . . . 13 69 8.3. Data Item Values . . . . . . . . . . . . . . . . . . . . 14 70 9. References . . . . . . . . . . . . . . . . . . . . . . . . . 14 71 9.1. Normative References . . . . . . . . . . . . . . . . . . 14 72 9.2. Informative References . . . . . . . . . . . . . . . . . 14 73 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 15 75 1. Introduction 77 The Dynamic Link Event Protocol (DLEP) is defined in 78 [I-D.ietf-manet-dlep]. It provides the exchange of link related 79 control information between DLEP peers. DLEP peers are comprised of 80 a modem and a router. DLEP defines a base set of mechanisms as well 81 as support for possible extensions. This document defines one such 82 extension. 84 The base DLEP specification does not include any flow control 85 capability. There are various flow control theoretically possible 86 with DLEP. For example, a credit-windowing scheme for destination- 87 specific flow control which provides aggregate flow control for both 88 modem and routers has been proposed in 89 [I-D.ietf-manet-credit-window]. 91 This document defines a DLEP extension which provides flow control 92 for DiffServ [RFC2475] traffic sent from a router to a modem. Flow 93 control is provided for multiple DSCPs (differentiated services 94 codepoint), which are grouped into logical sets of logical queues. 95 The extension defined in this document is referred to as "DiffServ 96 Aware Credit Windowing" or, more simply, the "DA Credit" extension. 98 This document defines a new DLEP Extension Type Value in Section 3 99 which is used to indicate the use of the extension. Two new messages 100 are defined in Section 4, and four new DLEP Data Items in Section 5. 102 1.1. Key Words 104 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 105 "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and 106 "OPTIONAL" in this document are to be interpreted as described in BCP 107 14, RFC 2119 [RFC2119]. 109 2. Extension Overview 111 The DA Credit extension can be used to support credit based flow 112 control of traffic sent from a router to a modem. The extension can 113 be used to support DiffServ and non-DiffServ based flow control. 114 Both types of DLEP endpoints, i.e., a router and a modem, negotiate 115 the use of extension during session initialization, see Section 5.2 116 [I-D.ietf-manet-dlep]. 118 When the extension is to be used, a modem passes to a router its 119 known DSCPs, if any. DSCPs are grouped by logical queues, each of 120 which are given a logical queue index. The queue index zero (0) is 121 special and is used for any DSCP value, including 0, which is not 122 otherwise identified by the modem. The modem also provides a size, 123 in bytes, of the logical queue for informative and, potential, future 124 uses. Currently, only DSCP to logical queue index value mapping is 125 used in flow control operation. 127 The DA Credit extension supports credit based flow control on a per 128 MAC address destination, per queue index basis. Modems provide the 129 initial size of the associated "Credit Window", i.e., the amount in 130 octets (bytes) that may be sent by the router to the modem, when a 131 MAC destination becomes reachable and, optionally, when its rate 132 information changes. "Credit Increments", i.e., increases in a 133 Credit Window size, are provided using new "Credit Control" messages. 134 A router provides its view of the Credit Window, which is known as 135 "status", in Destination Up Response and the new "Credit Control 136 Response" messages. Routers can also request credits using the new 137 "Credit Control" message. 139 Credit information, both grants and status, is provided in new credit 140 grant related data items. Each data item contains a single credit 141 value that applies to one or more queue indexes. Different (grant 142 and status) values for different queue indexes can be provided in a 143 single message by including multiple grant data items. The values 144 indicate a number of octets (bytes), including MAC headers on the 145 router to modem link, that may be sent. 147 Note that credit information related to different destination MAC 148 addresses is always passed in different DLEP messages. 150 3. Extension Usage and Identification 152 The use of the extension defined in this document SHOULD be 153 configurable. To indicate that the DiffServ Aware Credit Windowing 154 Extension is to be used, an implementation MUST include the DiffServ 155 Aware Credit Windowing Type Value in the Extensions Supported Data 156 Item. The Extensions Supported Data Item is sent and processed 157 according to [I-D.ietf-manet-dlep]. 159 The DiffServ Aware Credit Windowing Extension Type Value is TBA1, see 160 Section 8. 162 4. Extension Messages 164 Two new messages are defined by this extension: the Credit Control 165 and the Credit Control Response message. Sending and receiving both 166 message types MUST be supported by any implementation that advertises 167 use of this extension per Section 3. 169 4.1. Credit Control Message 171 Credit Control Messages are sent by modems to provide Credit 172 Increments. For messages sent by modems, only one message per MAC 173 address can be outstanding at one time. That is, a modem MUST NOT 174 send a second (or any subsequent) message containing the same MAC 175 Address until a Credit Control Response message is received from its 176 peer router with that MAC address. 178 Credit Control Messages MAY be sent by routers, e.g., to request 179 credits or provide window status. No specific response message is 180 required from a message transaction perspective. 182 [TBD: Should anything be said about sending, or limiting, multiple 183 credit requests?] 185 The Message Type value in the DLEP Message Header is set to TBA2. 187 The message MUST contain a DLEP MAC Address Data Item. 189 A message sent by a modem, MUST contain one or more DiffServ Aware 190 Credit Grant data items as defined below in Section 5.2. A router 191 receiving this message MUST respond with a Credit Control Response 192 Message. 194 A message sent by a router, MUST contain the DiffServ Aware Credit 195 Request data item defined below in Section 5.4. A modem receiving 196 this message MUST provide a Credit Increment for the indicated MAC 197 address and queue indexes via a new Credit Control Message. 199 Specific processing associated with each Credit data item is provided 200 below. 202 4.2. Credit Control Response Message 204 Credit Control Response Messages are sent by routers to report the 205 current Credit Window for a destination. 207 The Message Type value in the DLEP Message Header is set to TBA3. 209 The message MUST contain a DLEP MAC Address Data Item. 211 A message sent by a router, MUST contain one or more DiffServ Aware 212 Credit Window Status data items as defined below in Section 5.3. 214 Specific processing associated with the DA Credit Window Status data 215 item is provided below. 217 5. Extension Data Items 219 Four data items are defined by this extension. The Queue Parameters 220 Data Item is used by a modem to provide information on the DSCPs it 221 uses in forwarding. The DA Credit Grant is used by a modem to 222 provide credits to a router. The DA Credit Request is used by a 223 router to request additional credits. The DA Credit Window Status is 224 used to advertise the sender's view of number of available credits 225 for synchronization purposes. 227 The defined data items and operations are similar to those found in 228 [I-D.ietf-manet-credit-window]. One notable difference from this 229 extension is that in this document credits are never provided by the 230 router to the modem. 232 5.1. Queue Parameters 234 The Queue Parameters Data Item is used by a modem to indicate DSCP 235 values that may be independently controlled. This data item MUST be 236 included in a Session Initialization Response Message that also 237 contains the DiffServ Aware Credit Windowing Extension Type Value in 238 the Extensions Supported Data Item. Updates to these parameters MAY 239 be sent by a modem by including the data item in Session Update 240 Messages. 242 The Queue Parameters Data Item identifies DSCPs based on groups of 243 logical queues. The number of logical queues is variable as is the 244 number of DSCPs associated with each queue. A queue size (in bytes) 245 is provided for informational purposes. An implementation that does 246 not support DSCPs would indicate 1 queue with 0 DSCPs, and the number 247 of bytes that may be in its associated link transmit queue. 249 The format of the Queue Parameters Data Item is: 251 0 1 2 3 252 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 1 253 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 254 | Data Item Type | Length | 255 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 256 | Num Queues | Scale | Reserved | 257 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 258 |Num DSCPs Q0(0)| Queue Size Q0 | 259 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 260 | Num DSCPs Q1 | Queue Size Q1 | 261 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 262 | Num DSCPs Q2 | Queue Size Q2 | 263 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 264 : ... : 265 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 266 | Num DSCPs Qn | Queue Size Qn | 267 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 268 | DS Field Q1 | DS Field Q1 | DS Field Q1 | DS Field Q2 | 269 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 270 : ... | DS Field Qn | 271 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 273 Data Item Type: TBA4 275 Length: Variable 277 Per [I-D.ietf-manet-dlep] Length is the number of octets in the 278 data item, excluding the Type and Length fields. 280 Num Queues: 282 An 8-bit unsigned integer indicating the number of queues 283 represented in the data item. This field MUST contain a value of 284 at least one (1). Note that this number is one larger than the 285 largest queue index value included in the data item. 287 Scale: 289 An 4-bit unsigned integer indicating the scale used in the Queue 290 Size fields. The valid values are: 292 Value Scale 293 ------------ 294 0 B - Bytes (Octets) 295 1 KB - Kilobytes (B/1024) 296 2 MB - Megabytes (KB/1024) 297 3 GB - Gigabytes (MB/1024) 299 Reserved: 301 MUST be set to zero by the sender (a modem) and ignored by the 302 receiver (a router). 304 Num DSCPs Qn: 306 An 8-bit unsigned integer indicating the number of DSCPs 307 associated with the indexed queue. Other than the special case 308 covered in the next paragraph, this field MUST contain a value of 309 at least one (1). Queue indexes start at zero (0) and the maximum 310 queue index "Qn" is one less than the value carried in the Num 311 Queues field. Queue indexes are implicit in the position in the 312 data item. 314 Queue index zero "Q0" is a special case. It is used for any 315 traffic that does not carry a DSCP value represented in the data 316 item. Therefore the value of the Queue index zero field, "Num 317 DSCPs Q0", field MUST be zero (0). 319 Queue Size Qn: 321 A 24-bit unsigned integer representing the size, in the octet 322 scale indicated by the Scale field, of the queue supporting 323 traffic with the DSCPs associated with the queue index. 325 DS Field Qn: 327 The data item contains a sequence of 8 bit DS Fields. The 328 position in the sequence identifies the associated queue index. 329 The number of DS Fields present should equal the sum of all Num 330 DSCPs field values. 332 The DS Field structure is the same as [RFC2474]. 334 0 1 2 3 4 5 6 7 335 +---+---+---+---+---+---+---+---+ 336 | DSCP | CU | 337 +---+---+---+---+---+---+---+---+ 339 DSCP: differentiated services codepoint 340 CU: currently unused, MUST be zero 342 5.2. DiffServ Aware (DA) Credit Grant 344 The DiffServ Aware, or DA, Credit Grant data item is used by a modem 345 to provide credits to a router. One or more DA Credit Grant data 346 items MAY be carried in the DLEP Destination Up, Destination Announce 347 Response, Destination Update, and Credit Control messages. Multiple 348 DA Credit Grant data items in a single message are used to indicated 349 different credit values for different logical queues. 351 In Destination type messages, this data item provides the total 352 number of octets available in the Credit Window to the destination 353 indicated in the message for the specified logical queues. In the 354 Credit Control message, this data item provides an additional number 355 of octets to be added to the Credit Window to the destination 356 indicated in the message for the specified logical queues. 358 Logical queues are identified using a Queue Index as defined above in 359 Section 5.1. Multiple Queue Indexes MAY be present to allow for the 360 case where same credit information applies to multiple queues. As 361 mentioned above, multiple DA Credit Grant Data Items MAY be present 362 to provide different queue-specific credit information in one 363 message. The special Queue Index value of 255 is used to indicate 364 that the credit information applies to all queues. 366 The format of the DA Credit Grant Data Item is: 368 0 1 2 3 369 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 1 370 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 371 | Data Item Type | Length | 372 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 373 | Credit Value | 374 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 375 | Credit value | 376 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 377 | Queue Index | ... : 378 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 379 : ... | Queue Index | 380 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 382 Data Item Type: TBA5 384 Length: Variable 386 Per [I-D.ietf-manet-dlep], Length is the number of octets in the 387 data item, excluding the Type and Length fields. It will equal 8 388 plus the number of Queue Index fields carried in the data item and 389 MUST be at least 9. 391 Credit Value: 393 A 64-bit unsigned integer representing the credits, in octets, to 394 be applied to the Credit Window. This value includes MAC headers 395 as seen on the link between the modem and router. 397 Queue Index: 399 One or more 8-bit fields used to indicate a queue index defined by 400 a Queue Parameters Data Item. The special value of 255 indicates 401 that the information in the data item applies to all queue 402 indexes. 404 Receive processing of this data item is based on the message in which 405 it is carried. When this data item is received in a Destination type 406 message, the Credit Window of the indicated destination MAC address 407 and indicated queue indexes MUST be set to the value contained in the 408 Credit Value field. 410 When this data item is received in a Credit Control message, the 411 Credit Window of the indicated destination MAC address and indicated 412 queue indexes MUST be increased by the value contained in the Credit 413 Value field. If the increase results in a window overflow, i.e., the 414 Credit Window resulting after the increase is smaller than the 415 original Credit Window, the Credit Window must be set to its maximum 416 (0xFFFFFFFFFFFFFFFF). 418 Independent of the received message, the receiving router MUST send a 419 DA Credit Window Status data item or items reflecting the resulting 420 Credit Window value of each modified queue index. When the Credit 421 Grant data item is received in a Destination Up message, the DA 422 Credit Window Status data item(s) MUST be sent in the corresponding 423 Destination Up Response message. In all other cases, the a Credit 424 Control message MUST be sent. 426 5.3. DiffServ Aware (DA) Credit Window Status 428 The DiffServ Aware, or DA, Credit Window Status data item is used by 429 a router to report the current Credit Window to its peer modem. One 430 or more DA Credit Window Status data items MAY be carried in a 431 Destination Up Response message or a Credit Control Response message. 432 As discussed above, the Destination Up Response message is used when 433 the data item is sent in response to a Destination Up message, and 434 the Credit Control Response message is sent in response to a Credit 435 Control message. Multiple DA Credit Window Status data items in a 436 single message are used to indicated different credit window values 437 for different logical queues. 439 Similar to the DA Credit Grant, logical queues are identified using a 440 Queue Index as defined above in Section 5.1. Multiple Queue Indexes 441 MAY be present to allow for the case where same credit information 442 applies to multiple queues. Multiple DA Credit Window Status Data 443 Items are used to provide different queue-specific credit window 444 information in one message. The special Queue Index value of 255 is 445 used to indicate that the Credit Window information applies to all 446 queues. 448 The format of the DA Credit Window Status Data Item is: 450 0 1 2 3 451 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 1 452 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 453 | Data Item Type | Length | 454 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 455 | Credit Window : 456 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 457 : Credit Window | 458 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 459 | Queue Index | ... : 460 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 461 : ... | Queue Index | 462 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 464 Data Item Type: TBA6 466 Length: Variable 468 Per [I-D.ietf-manet-dlep] Length is the number of octets in the 469 data item, excluding the Type and Length fields. It will equal 8 470 plus the number of Queue Index fields carried in the data item and 471 MUST be at least 9. 473 Credit Window: 475 A 64-bit unsigned integer, indicating the current number of 476 credits, in octets, available for the router to send to the modem. 477 This is referred to as the Modem Receive Window in 478 [I-D.ietf-manet-credit-window]. 480 Queue Index: 482 One or more 8-bit fields used to indicate a queue index defined by 483 a Queue Parameters Data Item. The special value of 255 indicates 484 that the information in the data item applies to all queue 485 indexes. 487 The receiving modem SHOULD check the received Credit Window value 488 against the outstanding credits available at the time the last Credit 489 Increment associated with the indicated MAC address and Queue Indexes 490 were sent. If the values significantly differ, i.e., greater than 491 can be accounted for based on observed data frames, then the modem 492 SHOULD send a Destination Update message carrying a DA Credit Grant 493 data item to reset the associated Credit Window(s) to the data item 494 indicated value. Multiple values and queue indexes SHOULD be 495 combined into a single Destination Update Control message when 496 possible. Alternatively, and also in cases where there are small 497 differences, the modem MAY adjust the values sent in DA Credit Grant 498 data items to account for the reported Credit Window. 500 5.4. DiffServ Aware (DA) Credit Request 502 The DiffServ Aware, or DA, Credit Request Data Item data item is used 503 by a router to request additional credits for a specific destination 504 and Queue Index associated Credit window. DA Credit Request data 505 items are carried in Credit Control messages, and only one DA Credit 506 Request data item SHOULD be present in a message. 508 Logical queues are identified using a Queue Index as defined above in 509 Section 5.1. Multiple Queue Indexes MAY be present to allow for the 510 case where the credit request applies to multiple queues. The 511 special Queue Index value of 255 is used to indicate that a credit 512 request is being made across all queues. 514 The format of the DA Credit Request Data Item is: 516 0 1 2 3 517 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 1 518 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 519 | Data Item Type | Length | 520 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 521 | Queue Index | ... : 522 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 523 : ... | Queue Index | 524 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 526 [LB note: a list of Queue Indexes is now supported as is special 527 value 255.] 529 Data Item Type: TBA7 531 Length: Variable 533 Per [I-D.ietf-manet-dlep] Length is the number of octets in the 534 data item, excluding the Type and Length fields. It will equal 535 the number of Queue Index fields carried in the data item and MUST 536 be at least 1. 538 Queue Index: 540 One or more 8-bit fields used to indicate a queue index defined by 541 a Queue Parameters Data Item. The special value of 255 indicates 542 that the request applies to all queue indexes. 544 A modem receiving this data item MUST provide a Credit Increment for 545 the indicated MAC address and queue indexes via a DA Credit Grant 546 carried in a new Credit Control Message. Multiple values and queue 547 indexes SHOULD be combined into a single Credit Control message when 548 possible. 550 6. Compatibility 552 Sessions established with both peers identified as supporting the 553 DiffServ Aware Credit Windowing Extension Type, see Section 3, SHOULD 554 NOT use the [I-D.ietf-manet-credit-window] defined Credit data items. 555 If a node supporting the extension defined in this document, receives 556 a [I-D.ietf-manet-credit-window] defined data item, the recipient 557 MUST treat the received credit information as applying to Queue Index 558 zero (0). 560 7. Security Considerations 562 The extension introduces a DiffServ awareness to the mechanisms 563 defined in [I-D.ietf-manet-credit-window]. The extension does not 564 inherently introduce any additional threats above those documented in 565 [I-D.ietf-manet-dlep]. The approach taken to Security in that 566 document and [I-D.ietf-manet-credit-window] apply equally when 567 running the extension defined in this document. 569 8. IANA Considerations 571 This document requests the assignment of 5 values by IANA. All 572 assignments are to registries defined by [I-D.ietf-manet-dlep]. 574 8.1. Extension Type Value 576 This document requests 1 new assignment to the DLEP Extensions 577 Registry named "Extension Tyoe Values" in the range with the 578 "Specification Required" policy. The requested value is as follows: 580 +------+---------------------------------+ 581 | Code | Description | 582 +------+---------------------------------+ 583 | TBA1 | DiffServ Aware Credit Windowing | 584 +------+---------------------------------+ 586 Table 1: Requested Extension Type Value 588 8.2. Message Values 590 This document requests 2 new assignments to the DLEP Message Registry 591 named "Message Values" in the range with the "Specification Required" 592 policy. The requested values are as follows: 594 +-----------+-------------------------+ 595 | Type Code | Description | 596 +-----------+-------------------------+ 597 | TBA2 | Credit Control | 598 | | | 599 | TBA3 | Credit Control Response | 600 +-----------+-------------------------+ 602 Table 2: Requested Message Values 604 8.3. Data Item Values 606 This document requests 4 new assignments to the DLEP Data Item 607 Registry named "Data Item Values" in the range with the 608 "Specification Required" policy. The requested values are as 609 follows: 611 +-----------+-------------------------+ 612 | Type Code | Description | 613 +-----------+-------------------------+ 614 | TBA4 | Queue Parameters | 615 | | | 616 | TBA5 | DA Credit Grant | 617 | | | 618 | TBA6 | DA Credit Window Status | 619 | | | 620 | TBA7 | DA Credit Request | 621 +-----------+-------------------------+ 623 Table 3: Requested Data Item Values 625 9. References 627 9.1. Normative References 629 [I-D.ietf-manet-dlep] 630 Ratliff, S., Jury, S., Satterwhite, D., Taylor, R., and (. 631 (Unknown), "Dynamic Link Exchange Protocol (DLEP)", draft- 632 ietf-manet-dlep-24 (work in progress), July 2016. 634 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 635 Requirement Levels", BCP 14, RFC 2119, 636 DOI 10.17487/RFC2119, March 1997, 637 . 639 9.2. Informative References 641 [I-D.ietf-manet-credit-window] 642 Ratliff, S., "Credit Windowing extension for DLEP", draft- 643 ietf-manet-credit-window-04 (work in progress), April 644 2016. 646 [RFC2474] Nichols, K., Blake, S., Baker, F., and D. Black, 647 "Definition of the Differentiated Services Field (DS 648 Field) in the IPv4 and IPv6 Headers", RFC 2474, 649 DOI 10.17487/RFC2474, December 1998, 650 . 652 [RFC2475] Blake, S., Black, D., Carlson, M., Davies, E., Wang, Z., 653 and W. Weiss, "An Architecture for Differentiated 654 Services", RFC 2475, DOI 10.17487/RFC2475, December 1998, 655 . 657 Authors' Addresses 659 Bow-Nan Cheng 660 Lincoln Laboratory 661 Massachusetts Institute of Technology 662 244 Wood Street 663 Lexington, MA 02420-9108 665 Email: bcheng@ll.mit.edu 667 David Wiggins 668 Lincoln Laboratory 669 Massachusetts Institute of Technology 670 244 Wood Street 671 Lexington, MA 02420-9108 673 Email: David.Wiggins@ll.mit.edu 675 Lou Berger 676 LabN Consulting, L.L.C. 678 Email: lberger@labn.net