idnits 2.17.1 draft-ietf-tsvwg-addip-sctp-16.txt: Checking boilerplate required by RFC 5378 and the IETF Trust (see https://trustee.ietf.org/license-info): ---------------------------------------------------------------------------- ** It looks like you're using RFC 3978 boilerplate. You should update this to the boilerplate described in the IETF Trust License Policy document (see https://trustee.ietf.org/license-info), which is required now. -- Found old boilerplate from RFC 3978, Section 5.1 on line 22. -- Found old boilerplate from RFC 3978, Section 5.5 on line 1538. -- Found old boilerplate from RFC 3979, Section 5, paragraph 1 on line 1549. -- Found old boilerplate from RFC 3979, Section 5, paragraph 2 on line 1556. -- Found old boilerplate from RFC 3979, Section 5, paragraph 3 on line 1562. ** This document has an original RFC 3978 Section 5.4 Copyright Line, instead of the newer IETF Trust Copyright according to RFC 4748. ** This document has an original RFC 3978 Section 5.5 Disclaimer, instead of the newer disclaimer which includes the IETF Trust according to RFC 4748. 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 : ---------------------------------------------------------------------------- ** The document seems to lack separate sections for Informative/Normative References. All references will be assumed normative when checking for downward references. ** The abstract seems to contain references ([RFC2960]), which it shouldn't. Please replace those with straight textual mentions of the documents in question. == There are 4 instances of lines with non-RFC6890-compliant IPv4 addresses in the document. If these are example addresses, they should be changed. == There are 3 instances of lines with private range IPv4 addresses in the document. If these are generic example addresses, they should be changed to use any of the ranges defined in RFC 6890 (or successor): 192.0.2.x, 198.51.100.x or 203.0.113.x. Miscellaneous warnings: ---------------------------------------------------------------------------- == The copyright year in the RFC 3978 Section 5.4 Copyright Line does not match the current year == The document seems to lack the recommended RFC 2119 boilerplate, even if it appears to use RFC 2119 keywords. (The document does seem to have the reference to RFC 2119 which the ID-Checklist requires). == Using lowercase 'not' together with uppercase 'MUST', 'SHALL', 'SHOULD', or 'RECOMMENDED' is not an accepted usage according to RFC 2119. Please use uppercase 'NOT' together with RFC 2119 keywords (if that is what you mean). Found 'SHOULD not' in this paragraph: C5) An ASCONF Chunk and an ASCONF-ACK Chunk SHOULD not be larger than the path MTU. -- The document seems to lack a disclaimer for pre-RFC5378 work, but may have content which was first submitted before 10 November 2008. If you have contacted all the original authors and they are all willing to grant the BCP78 rights to the IETF Trust, then this is fine, and you can ignore this comment. If not, you may need to add the pre-RFC5378 disclaimer. (See the Legal Provisions document at https://trustee.ietf.org/license-info for more information.) -- The document date (October 23, 2006) is 6385 days in the past. Is this intentional? Checking references for intended status: Informational ---------------------------------------------------------------------------- == Unused Reference: 'RFC2026' is defined on line 1319, but no explicit reference was found in the text == Unused Reference: 'RFC2402' is defined on line 1325, but no explicit reference was found in the text == Unused Reference: 'RFC2629' is defined on line 1332, but no explicit reference was found in the text ** Obsolete normative reference: RFC 2402 (Obsoleted by RFC 4302, RFC 4305) ** Obsolete normative reference: RFC 2434 (Obsoleted by RFC 5226) ** Obsolete normative reference: RFC 2629 (Obsoleted by RFC 7749) ** Obsolete normative reference: RFC 2960 (Obsoleted by RFC 4960) == Outdated reference: A later version (-08) exists of draft-ietf-tsvwg-sctp-auth-04 Summary: 9 errors (**), 0 flaws (~~), 9 warnings (==), 7 comments (--). Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 2 Network Working Group R. Stewart 3 Internet-Draft Cisco Systems, Inc. 4 Intended status: Informational Q. Xie 5 Expires: April 26, 2007 Motorola, Inc. 6 M. Tuexen 7 Univ. of Applied Sciences Muenster 8 S. Maruyama 9 M. Kozuka 10 Kyoto University 11 October 23, 2006 13 Stream Control Transmission Protocol (SCTP) Dynamic Address 14 Reconfiguration 15 draft-ietf-tsvwg-addip-sctp-16.txt 17 Status of this Memo 19 By submitting this Internet-Draft, each author represents that any 20 applicable patent or other IPR claims of which he or she is aware 21 have been or will be disclosed, and any of which he or she becomes 22 aware will be disclosed, in accordance with Section 6 of BCP 79. 24 Internet-Drafts are working documents of the Internet Engineering 25 Task Force (IETF), its areas, and its working groups. Note that 26 other groups may also distribute working documents as Internet- 27 Drafts. 29 Internet-Drafts are draft documents valid for a maximum of six months 30 and may be updated, replaced, or obsoleted by other documents at any 31 time. It is inappropriate to use Internet-Drafts as reference 32 material or to cite them other than as "work in progress." 34 The list of current Internet-Drafts can be accessed at 35 http://www.ietf.org/ietf/1id-abstracts.txt. 37 The list of Internet-Draft Shadow Directories can be accessed at 38 http://www.ietf.org/shadow.html. 40 This Internet-Draft will expire on April 26, 2007. 42 Copyright Notice 44 Copyright (C) The Internet Society (2006). 46 Abstract 48 This document describes extensions to the Stream Control Transmission 49 Protocol (SCTP) [RFC2960] that provides a method to reconfigure IP 50 address information on an existing association. 52 Table of Contents 54 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 4 55 2. Conventions . . . . . . . . . . . . . . . . . . . . . . . . . 4 56 3. Additional Chunks and Parameters . . . . . . . . . . . . . . . 4 57 3.1. New Chunk Types . . . . . . . . . . . . . . . . . . . . . 5 58 3.1.1. Address Configuration Change Chunk (ASCONF) . . . . . 5 59 3.1.2. Address Configuration Acknowledgment Chunk 60 (ASCONF-ACK) . . . . . . . . . . . . . . . . . . . . . 7 61 3.2. New Parameter Types . . . . . . . . . . . . . . . . . . . 7 62 3.2.1. Add IP Address . . . . . . . . . . . . . . . . . . . . 8 63 3.2.2. Delete IP Address . . . . . . . . . . . . . . . . . . 9 64 3.2.3. Error Cause Indication . . . . . . . . . . . . . . . . 10 65 3.2.4. Set Primary IP Address . . . . . . . . . . . . . . . . 11 66 3.2.5. Success Indication . . . . . . . . . . . . . . . . . . 12 67 3.2.6. Adaptation Layer Indication . . . . . . . . . . . . . 13 68 3.2.7. Supported Extensions Parameter . . . . . . . . . . . . 13 69 3.3. New Error Causes . . . . . . . . . . . . . . . . . . . . . 14 70 3.3.1. Error Cause: Request to Delete Last Remaining IP 71 Address . . . . . . . . . . . . . . . . . . . . . . . 15 72 3.3.2. Error Cause: Operation Refused Due to Resource 73 Shortage . . . . . . . . . . . . . . . . . . . . . . . 15 74 3.3.3. Error Cause: Request to Delete Source IP Address . . . 16 75 3.3.4. Error Cause: Association Aborted due to illegal 76 ASCONF-ACK . . . . . . . . . . . . . . . . . . . . . . 17 77 3.3.5. Error Cause: Request refused - no authorization. . . . 17 78 4. Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . 18 79 4.1. ASCONF Chunk Procedures . . . . . . . . . . . . . . . . . 18 80 4.1.1. Congestion Control of ASCONF Chunks . . . . . . . . . 20 81 4.2. Upon reception of an ASCONF Chunk. . . . . . . . . . . . . 21 82 4.3. General rules for address manipulation . . . . . . . . . . 23 83 4.3.1. A special case for OOTB ABORT Chunks . . . . . . . . . 27 84 4.3.2. A special case for changing an address. . . . . . . . 27 85 4.4. Setting of the primary address . . . . . . . . . . . . . . 28 86 4.5. Bundling of multiple ASCONFs . . . . . . . . . . . . . . . 28 87 5. Security Considerations . . . . . . . . . . . . . . . . . . . 29 88 6. IANA considerations . . . . . . . . . . . . . . . . . . . . . 29 89 7. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 30 90 8. References . . . . . . . . . . . . . . . . . . . . . . . . . . 31 91 Appendix A. Abstract Address Handling . . . . . . . . . . . . . . 31 92 A.1. General remarks . . . . . . . . . . . . . . . . . . . . . 31 93 A.2. Generalized endpoints . . . . . . . . . . . . . . . . . . 31 94 A.3. Associations . . . . . . . . . . . . . . . . . . . . . . . 32 95 A.4. Relationship with RFC 2960 . . . . . . . . . . . . . . . . 33 96 A.5. Rules for address manipulation . . . . . . . . . . . . . . 33 97 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 34 98 Intellectual Property and Copyright Statements . . . . . . . . . . 36 100 1. Introduction 102 To extend the utility and application scenarios of SCTP, this 103 document introduces optional extensions that provide SCTP with the 104 ability to: 106 1. reconfigure IP address information on an existing association. 107 2. set the remote primary path. 108 3. exchange adaptation layer information during association setup. 110 These extensions enable SCTP to be utilized in the following 111 applications: 113 1. For computational or networking platforms that allow addition/ 114 removal of physical interface cards this feature can provide a 115 graceful method to add to the interfaces of an existing 116 association. For IPv6 this feature allows renumbering of 117 existing associations. 118 2. This provides a method for an endpoint to request that its peer 119 set its primary destination address. This can be useful when an 120 address is about to be deleted, or when an endpoint has some 121 predetermined knowledge about which is the preferred address to 122 receive SCTP packets upon. 123 3. This feature can be used to extend the usability of SCTP without 124 modifying it by allowing endpoints to exchange some information 125 during association setup. 127 2. Conventions 129 The keywords MUST, MUST NOT, REQUIRED, SHALL, SHALL NOT, SHOULD, 130 SHOULD NOT, RECOMMENDED, NOT RECOMMENDED, MAY, and OPTIONAL, when 131 they appear in this document, are to be interpreted as described in 132 RFC2119 [RFC2119]. 134 3. Additional Chunks and Parameters 136 This section describes the addition of two new chunks and, seven new 137 parameters to allow: 139 o Dynamic addition of IP Addresses to an association. 140 o Dynamic deletion of IP Addresses from an association. 141 o A request to set the primary address the peer will use when 142 sending to an endpoint. 144 Additionally, this section describes three new error causes that 145 support these new chunks and parameters. 147 3.1. New Chunk Types 149 This section defines two new chunk types that will be used to 150 transfer the control information reliably. Table 1 illustrates the 151 two new chunk types. 153 Chunk Type Chunk Name 154 -------------------------------------------------------------- 155 0xC1 Address Configuration Change Chunk (ASCONF) 156 0x80 Address Configuration Acknowledgment (ASCONF-ACK) 158 Table 1: Address Configuration Chunks 160 It should be noted that the ASCONF Chunk format requires the receiver 161 to report to the sender if it does not understand the ASCONF Chunk. 162 This is accomplished by setting the upper bits in the chunk type as 163 described in RFC2960 [RFC2960] section 3.2. Note: that the upper two 164 bits in the ASCONF Chunk are set to one. As defined in RFC2960 165 [RFC2960] section 3.2, setting these upper bits in this manner will 166 cause the receiver that does not understand this chunk to skip the 167 chunk and continue processing, but report in an Operation Error Chunk 168 using the 'Unrecognized Chunk Type' cause of error. 170 3.1.1. Address Configuration Change Chunk (ASCONF) 172 This chunk is used to communicate to the remote endpoint one of the 173 configuration change requests that MUST be acknowledged. The 174 information carried in the ASCONF Chunk uses the form of a Type- 175 Length-Value (TLV), as described in "3.2.1 Optional/Variable-length 176 Parameter Format" in RFC2960 [RFC2960], for all variable parameters. 177 This chunk MUST be sent in an authenticated way by using the 178 mechanism defined in SCTP-AUTH [I-D.ietf-tsvwg-sctp-auth]. If this 179 chunk is received unauthenticated it MUST be silently discarded as 180 described in SCTP-AUTH [I-D.ietf-tsvwg-sctp-auth]. 182 0 1 2 3 183 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 1 184 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 185 | Type = 0xC1 | Chunk Flags | Chunk Length | 186 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 187 | Serial Number | 188 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 189 | Address Parameter | 190 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 191 | ASCONF Parameter #1 | 192 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 193 \ \ 194 / .... / 195 \ \ 196 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 197 | ASCONF Parameter #N | 198 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 200 Serial Number : 32 bits (unsigned integer) 202 This value represents a Serial Number for the ASCONF Chunk. The 203 valid range of Serial Number is from 0 to 4294967295 (2**32 - 1). 204 Serial Numbers wrap back to 0 after reaching 4294967295. 206 Address Parameter : 8 or 20 bytes (depending on type) 208 This field contains an address parameter, either IPv6 or IPv4, from 209 RFC2960 [RFC2960]. The address is an address of the sender of the 210 ASCONF Chunk, the address MUST be considered part of the association 211 by the peer endpoint (the receiver of the ASCONF Chunk). This field 212 may be used by the receiver of the ASCONF to help in finding the 213 association. If the address 0.0.0.0 or ::0 is provided the receiver 214 MAY lookup the association by other information provided in the 215 packet. This parameter MUST be present in every ASCONF message i.e. 216 it is a mandatory TLV parameter. 218 Note: the host name address parameter is NOT allowed and MUST be 219 ignored if received in any ASCONF message. 221 ASCONF Parameter: TLV format 223 Each Address configuration change is represented by a TLV parameter 224 as defined in Section 3.2. One or more requests may be present in an 225 ASCONF Chunk. 227 3.1.2. Address Configuration Acknowledgment Chunk (ASCONF-ACK) 229 This chunk is used by the receiver of an ASCONF Chunk to acknowledge 230 the reception. It carries zero or more results for any ASCONF 231 Parameters that were processed by the receiver. This chunk MUST be 232 sent in an authenticated way by using the mechanism defined in SCTP- 233 AUTH [I-D.ietf-tsvwg-sctp-auth]. If this chunk is received 234 unauthenticated it MUST be silently discarded as described in SCTP- 235 AUTH [I-D.ietf-tsvwg-sctp-auth]. 237 0 1 2 3 238 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 1 239 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 240 | Type = 0x80 | Chunk Flags | Chunk Length | 241 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 242 | Serial Number | 243 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 244 | ASCONF Parameter Response#1 | 245 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 246 \ \ 247 / .... / 248 \ \ 249 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 250 | ASCONF Parameter Response#N | 251 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 253 Serial Number : 32 bits (unsigned integer) 255 This value represents the Serial Number for the received ASCONF Chunk 256 that is acknowledged by this chunk. This value is copied from the 257 received ASCONF Chunk. 259 ASCONF Parameter Response : TLV format 261 The ASCONF Parameter Response is used in the ASCONF-ACK to report 262 status of ASCONF processing. By default, if a responding endpoint 263 does not include any Error Cause, a success is indicated. Thus a 264 sender of an ASCONF-ACK MAY indicate complete success of all TLVs in 265 an ASCONF by returning only the Chunk Type, Chunk Flags, Chunk Length 266 (set to 8) and the Serial Number. 268 3.2. New Parameter Types 270 The seven new parameters added follow the format defined in section 271 3.2.1 of RFC2960 [RFC2960]. Table 2, 3 and 4 describes the 272 parameters. 274 Address Configuration Parameters Parameter Type 275 ------------------------------------------------- 276 Set Primary Address 0xC004 277 Adaptation Layer Indication 0xC006 278 Supported Extensions 0x8008 280 Table 2: Parameters that can be used in INIT/INIT-ACK chunk 282 Address Configuration Parameters Parameter Type 283 ------------------------------------------------- 284 Add IP Address 0xC001 285 Delete IP Address 0xC002 286 Set Primary Address 0xC004 288 Table 3: Parameters used in ASCONF Parameter 290 Address Configuration Parameters Parameter Type 291 ------------------------------------------------- 292 Error Cause Indication 0xC003 293 Success Indication 0xC005 295 Table 4: Parameters used in ASCONF Parameter Response 297 Any parameter that appears where it is not allowed (for example a 298 0xC002 parameter appearing within an INIT or INIT-ACK) MAY be 299 responded to with an ABORT by the receiver of the invalid parameter. 301 3.2.1. Add IP Address 303 0 1 2 3 304 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 1 305 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 306 | Type = 0xC001 | Length = Variable | 307 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 308 | ASCONF-Request Correlation ID | 309 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 310 | Address Parameter | 311 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 313 ASCONF-Request Correlation ID: 32 bits 315 This is an opaque integer assigned by the sender to identify each 316 request parameter. It is in host byte order and is only meaningful 317 to the sender. The receiver of the ASCONF Chunk will copy this 32 318 bit value into the ASCONF Response Correlation ID field of the 319 ASCONF-ACK response parameter. The sender of the ASCONF can use this 320 same value in the ASCONF-ACK to find which request the response is 321 for. 323 Address Parameter: TLV 325 This field contains an IPv4 or IPv6 address parameter as described in 326 3.3.2.1 of RFC2960 [RFC2960]. The complete TLV is wrapped within 327 this parameter. It informs the receiver that the address specified 328 is to be added to the existing association. This parameter MUST NOT 329 contain a broadcast or multicast address. If the address 0.0.0.0 or 330 ::0 is provided, the source address of the packet MUST be added. 332 An example TLV requesting that the IPv4 address 10.1.1.1 be added to 333 the association would look as follows: 335 +--------------------------------+ 336 | Type=0xC001 | Length = 16 | 337 +--------------------------------+ 338 | C-ID = 0x01023474 | 339 +--------------------------------+ 340 | Type=5 | Length = 8 | 341 +----------------+---------------+ 342 | Value=0x0a010101 | 343 +----------------+---------------+ 345 Valid Chunk Appearance 347 The Add IP Address parameter may only appear in the ASCONF Chunk 348 type. 350 3.2.2. Delete IP Address 352 0 1 2 3 353 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 1 354 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 355 | Type =0xC002 | Length = Variable | 356 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 357 | ASCONF-Request Correlation ID | 358 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 359 | Address Parameter | 360 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 362 ASCONF-Request Correlation ID: 32 bits 364 This is an opaque integer assigned by the sender to identify each 365 request parameter. It is in host byte order and is only meaningful 366 to the sender. The receiver of the ASCONF Chunk will copy this 32 367 bit value into the ASCONF Response Correlation ID field of the 368 ASCONF-ACK response parameter. The sender of the ASCONF can use this 369 same value in the ASCONF-ACK to find which request the response is 370 for. 372 Address Parameter: TLV 374 This field contains an IPv4 or IPv6 address parameter as described in 375 3.3.2.1 of RFC2960 [RFC2960]. The complete TLV is wrapped within 376 this parameter. It informs the receiver that the address specified 377 is to be removed from the existing association. This parameter MUST 378 NOT contain a broadcast or multicast address. If the address 0.0.0.0 379 or ::0 is provided, all addresses of the peer except the source 380 address of the packet MUST be deleted. 382 An example TLV deleting the IPv4 address 10.1.1.1 from an existing 383 association would look as follows: 385 +--------------------------------+ 386 | Type=0xC002 | Length = 16 | 387 +--------------------------------+ 388 | C-ID = 0x01023476 | 389 +--------------------------------+ 390 | Type=5 | Length = 8 | 391 +----------------+---------------+ 392 | Value=0x0a010101 | 393 +----------------+---------------+ 395 Valid Chunk Appearance 397 The Delete IP Address parameter may only appear in the ASCONF Chunk 398 type. 400 3.2.3. Error Cause Indication 402 0 1 2 3 403 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 1 404 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 405 | Type = 0xC003 | Length = Variable | 406 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 407 | ASCONF-Response Correlation ID | 408 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 409 | Error Cause(s) or Return Info on Success | 410 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 412 ASCONF-Response Correlation ID: 32 bits 414 This is an opaque integer assigned by the sender to identify each 415 request parameter. The receiver of the ASCONF Chunk will copy this 416 32 bit value from the ASCONF-Request Correlation ID into the ASCONF 417 Response Correlation ID field so the peer can easily correlate the 418 request to this response. 420 Error Cause(s): TLV(s) 422 When reporting an error this response parameter is used to wrap one 423 or more standard error causes normally found within an SCTP 424 Operational Error or SCTP Abort (as defined in RFC2960 [RFC2960]). 425 The Error Cause(s) follow the format defined in section 3.3.10 of 426 RFC2960 [RFC2960]. 428 Valid Chunk Appearance 430 The Error Cause Indication parameter may only appear in the ASCONF- 431 ACK Chunk type. 433 3.2.4. Set Primary IP Address 435 0 1 2 3 436 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 1 437 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 438 | Type =0xC004 | Length = Variable | 439 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 440 | ASCONF-Request Correlation ID | 441 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 442 | Address Parameter | 443 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 445 ASCONF-Request Correlation ID: 32 bits 447 This is an opaque integer assigned by the sender to identify each 448 request parameter. It is in host byte order and is only meaningful 449 to the sender. The receiver of the ASCONF Chunk will copy this 32 450 bit value into the ASCONF Response Correlation ID field of the 451 ASCONF-ACK response parameter. The sender of the ASCONF can use this 452 same value in the ASCONF-ACK to find which request the response is 453 for. 455 Address Parameter: TLV 457 This field contains an IPv4 or IPv6 address parameter as described in 458 3.3.2.1 of RFC2960 [RFC2960]. The complete TLV is wrapped within 459 this parameter. It requests the receiver to mark the specified 460 address as the primary address to send data to (see section 5.1.2 of 461 RFC2960 [RFC2960]). The receiver MAY mark this as its primary upon 462 receiving this request. If the address 0.0.0.0 or ::0 is provided, 463 the receiver MAY mark the source address of the packet as its 464 primary. 466 An example TLV requesting that the IPv4 address 10.1.1.1 be made the 467 primary destination address would look as follows: 469 +--------------------------------+ 470 | Type=0xC004 | Length = 16 | 471 +--------------------------------+ 472 | C-ID = 0x01023479 | 473 +--------------------------------+ 474 | Type=5 | Length = 8 | 475 +----------------+---------------+ 476 | Value=0x0a010101 | 477 +----------------+---------------+ 479 Valid Chunk Appearance 481 The Set Primary IP Address parameter may appear in the ASCONF Chunk, 482 the INIT, or the INIT-ACK chunk type. The inclusion of this 483 parameter in the INIT or INIT-ACK can be used to indicate an initial 484 preference of primary address. 486 3.2.5. Success Indication 488 0 1 2 3 489 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 1 490 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 491 | Type = 0xC005 | Length = 8 | 492 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 493 | ASCONF-Response Correlation ID | 494 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 496 By default if a responding endpoint does not report an error for any 497 requested TLV, a success is implicitly indicated. Thus a sender of a 498 ASCONF-ACK MAY indicate complete success of all TLVs in an ASCONF by 499 returning only the Chunk Type, Chunk Flags, Chunk Length (set to 8) 500 and the Serial Number. 502 The responding endpoint MAY also choose to explicitly report a 503 success for a requested TLV, by returning a success report ASCONF 504 Parameter Response. 506 ASCONF-Response Correlation ID: 32 bits 508 This is an opaque integer assigned by the sender to identify each 509 request parameter. The receiver of the ASCONF Chunk will copy this 510 32 bit value from the ASCONF-Request Correlation ID into the ASCONF 511 Response Correlation ID field so the peer can easily correlate the 512 request to this response. 514 Valid Chunk Appearance 516 The Success Indication parameter may only appear in the ASCONF-ACK 517 chunk type. 519 3.2.6. Adaptation Layer Indication 521 0 1 2 3 522 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 1 523 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 524 | Type =0xC006 | Length = 8 | 525 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 526 | Adaptation Code point | 527 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 529 This parameter is specified for the communication of peer upper layer 530 protocols. It is envisioned to be used for flow control and other 531 adaptation layers that require an indication to be carried in the 532 INIT and INIT-ACK. Each adaptation layer that is defined that wishes 533 to use this parameter MUST specify a an adaptation code point in an 534 appropriate RFC defining its use and meaning. This parameter SHOULD 535 NOT be examined by the receiving SCTP implementation and should be 536 passed opaquely to the upper layer protocol. 538 Valid Chunk Appearance 540 The Adaptation Layer Indication parameter may appear in INIT or INIT- 541 ACK chunk and SHOULD be passed to the receivers upper layer protocol. 542 This parameter MUST NOT appear in an ASCONF Chunk. 544 3.2.7. Supported Extensions Parameter 546 This parameter is used at startup to identify any additional 547 extensions that the sender supports. The sender MUST support both 548 the sending and the receiving of any chunk types listed within the 549 Supported Extensions Parameter. 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 | Parameter Type = 0x8008 | Parameter Length | 555 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 556 | CHUNK TYPE 1 | CHUNK TYPE 2 | CHUNK TYPE 3 | CHUNK TYPE 4 | 557 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 558 | .... | 559 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 560 | CHUNK TYPE N | PAD | PAD | PAD | 561 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 563 Parameter Type This field holds the IANA defined parameter type for 564 Supported Extensions Parameter. The suggested value of this field 565 for IANA is 0x8008. 567 Parameter Type Length This field holds the length of the parameter, 568 including the Parameter Type, Parameter Length and any addition 569 supported extensions. Note: the length MUST NOT include any 570 padding. 572 CHUNK TYPE X This field(s) hold the chunk type of any SCTP 573 extension(s) that are currently supported by the sending SCTP. 574 Multiple chunk types may be defined listing each additional 575 feature that the sender supports. The sender MUST NOT include 576 multiple Supported Extensions Parameter within any chunk. 578 Parameter Appearance This parameter may appear in the INIT or INIT- 579 ACK chunk. This parameter MUST NOT appear in any other chunk. 581 3.3. New Error Causes 583 Five new Error Causes are added to the SCTP Operational Errors, 584 primarily for use in the ASCONF-ACK Chunk. 586 Cause Code 587 Value Cause Code 588 --------- ---------------- 589 0x0100 Request to Delete Last Remaining IP Address. 590 0x0101 Operation Refused Due to Resource Shortage. 591 0x0102 Request to Delete Source IP Address. 592 0x0103 Association Aborted due to illegal ASCONF-ACK 593 0x0104 Request refused - no authorization. 595 Table 5: New Error Causes 597 3.3.1. Error Cause: Request to Delete Last Remaining IP Address 599 Cause of error 601 Request to Delete Last Remaining IP address: The receiver of this 602 error sent a request to delete the last IP address from its 603 association with its peer. This error indicates that the request is 604 rejected. 606 0 1 2 3 607 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 1 608 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 609 | Cause Code=0x0100 | Cause Length=Variable | 610 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 611 \ TLV-Copied-From-ASCONF / 612 / \ 613 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 615 An example of a failed delete in an Error Cause TLV would look as 616 follows in the response ASCONF-ACK message: 618 +--------------------------------+ 619 | Type = 0xC003 | Length = 28 | 620 +----------------+---------------+ 621 | C-ID = 0x01023476 | 622 +--------------------------------+ 623 | Cause=0x0100 | Length = 20 | 624 +----------------+---------------+ 625 | Type= 0xC002 | Length = 16 | 626 +----------------+---------------+ 627 | C-ID = 0x01023476 | 628 +--------------------------------+ 629 | Type=0x0005 | Length = 8 | 630 +----------------+---------------+ 631 | Value=0x0A010101 | 632 +----------------+---------------+ 634 3.3.2. Error Cause: Operation Refused Due to Resource Shortage 636 Cause of error 638 This error cause is used to report a failure by the receiver to 639 perform the requested operation due to a lack of resources. The 640 entire TLV that is refused is copied from the ASCONF into the error 641 cause. 643 0 1 2 3 644 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 1 645 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 646 | Cause Code=0x0101 | Cause Length=Variable | 647 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 648 \ TLV-Copied-From-ASCONF / 649 / \ 650 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 652 An example of a failed addition in an Error Cause TLV would look as 653 follows in the response ASCONF-ACK message: 655 +--------------------------------+ 656 | Type = 0xC003 | Length = 28 | 657 +--------------------------------+ 658 | C-ID = 0x01023474 | 659 +--------------------------------+ 660 | Cause=0x0101 | Length = 20 | 661 +----------------+---------------+ 662 | Type=0xC001 | Length = 16 | 663 +--------------------------------+ 664 | C-ID = 0x01023474 | 665 +--------------------------------+ 666 | Type=0x0005 | Length = 8 | 667 +----------------+---------------+ 668 | Value=0x0A010101 | 669 +----------------+---------------+ 671 3.3.3. Error Cause: Request to Delete Source IP Address 673 Cause of error 675 Request to Delete Source IP Address: The receiver of this error sent 676 a request to delete the source IP address of the ASCONF message. 677 This error indicates that the request is rejected. 679 0 1 2 3 680 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 1 681 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 682 | Cause Code=0x0102 | Cause Length=Variable | 683 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 684 \ TLV-Copied-From-ASCONF / 685 / \ 686 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 688 An example of a failed delete in an Error Cause TLV would look as 689 follows in the response ASCONF-ACK message: 691 +--------------------------------+ 692 | Type = 0xC003 | Length = 28 | 693 +--------------------------------+ 694 | C-ID = 0x01023476 | 695 +--------------------------------+ 696 | Cause=0x0102 | Length = 20 | 697 +----------------+---------------+ 698 | Type=0xC002 | Length = 16 | 699 +----------------+---------------+ 700 | C-ID = 0x01023476 | 701 +--------------------------------+ 702 | Type=0x0005 | Length = 8 | 703 +----------------+---------------+ 704 | Value=0x0A010101 | 705 +----------------+---------------+ 707 IMPLEMENTATION NOTE: It is unlikely that an endpoint would source a 708 packet from the address being deleted, unless the endpoint does not 709 do proper source address selection. 711 3.3.4. Error Cause: Association Aborted due to illegal ASCONF-ACK 713 This error is to be included in an ABORT that is generated due to the 714 reception of an ASCONF-ACK that was not expected but is larger than 715 the current sequence number (see Section 4.3 Rule D0 ). Note: that a 716 sequence number is larger than the last acked sequence number if it 717 is either the next sequence or no more than 2^^31-1 greater than the 718 current sequence number. 720 0 1 2 3 721 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 1 722 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 723 | Cause Code=0x0103 | Cause Length=4 | 724 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 726 3.3.5. Error Cause: Request refused - no authorization. 728 Cause of error 730 This error cause may be included to reject a request based on local 731 security policies. 733 0 1 2 3 734 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 1 735 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 736 | Cause Code=0x0104 | Cause Length=Variable | 737 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 738 \ TLV-Copied-From-ASCONF / 739 / \ 740 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 742 4. Procedures 744 This section will lay out the specific procedures for address 745 configuration change chunk type and its processing. 747 4.1. ASCONF Chunk Procedures 749 When an endpoint has an ASCONF signaled change to be sent to the 750 remote endpoint it should do the following: 752 A1) Create an ASCONF Chunk as defined in Section 3.1.1. The chunk 753 should contain all of the TLV(s) of information necessary to be 754 sent to the remote endpoint, and unique correlation identities for 755 each request. 757 A2) A serial number should be assigned to the Chunk. The serial 758 number should be a monotonically increasing number. The serial 759 number MUST be initialized at the start of the association to the 760 same value as the Initial TSN and every time a new ASCONF Chunk is 761 created it is incremented by one after assigning the serial number 762 to the newly created chunk . 764 A3) If no SCTP packet with one or more ASCONF Chunk(s) is 765 outstanding (un-acknowledged) with the remote peer, send the 766 chunk. 768 A4) Start a T-4 RTO timer, using the RTO value of the selected 769 destination address (normally the primary path; see RFC2960 770 [RFC2960] section 6.4 for details). 772 A5) When the ASCONF-ACK that acknowledges the serial number last 773 sent arrives, stop the T-4 RTO timer, and clear the appropriate 774 association and destination error counters as defined in RFC2960 775 [RFC2960] section 8.1 and 8.2. 777 A6) Process all of the TLVs within the ASCONF-ACK(s) to find out 778 particular status information returned to the various requests 779 that were sent. Use the Correlation IDs to correlate the request 780 and the responses. 782 A7) If an error response is received for a TLV parameter, all TLVs 783 with no response before the failed TLV are considered successful 784 if not reported. All TLVs after the failed response are 785 considered unsuccessful unless a specific success indication is 786 present for the parameter. 788 A8) If there is no response(s) to specific TLV parameter(s), and no 789 failures are indicated, then all request(s) are considered 790 successful. 792 A9) If the peer responds to an ASCONF with an ERROR chunk reporting 793 that it did not recognize the ASCONF Chunk type, the sender of the 794 ASCONF MUST NOT send any further ASCONF Chunks and MUST stop its 795 T-4 timer. 797 If the T-4 RTO timer expires the endpoint should do the following: 799 B1) Increment the error counters and perform path failure detection 800 on the appropriate destination address as defined in RFC2960 801 [RFC2960] section 8.1 and 8.2. 803 B2) Increment the association error counters and perform endpoint 804 failure detection on the association as defined in RFC2960 805 [RFC2960] section 8.1 and 8.2. 807 B3) Back-off the destination address RTO value to which the ASCONF 808 chunk was sent by doubling the RTO timer value. 810 Note: The RTO value is used in the setting of all timer types for 811 SCTP. Each destination address has a single RTO estimate. 813 B4) Re-transmit the ASCONF Chunk last sent and if possible choose an 814 alternate destination address (please refer to RFC2960 [RFC2960] 815 section 6.4.1). An endpoint MUST NOT add new parameters to this 816 chunk, it MUST be the same (including its serial number) as the 817 last ASCONF sent. An endpoint can, however, bundle an additional 818 ASCONF with new ASCONF parameters with the next sequence number. 819 For details see Section 4.5 821 B5) Restart the T-4 RTO timer. Note: that if a different 822 destination is selected, then the RTO used will be that of the new 823 destination address. 825 Note: the total number of re-transmissions is limited by B2 above. 826 If the maximum is reached, the association will fail and enter into 827 the CLOSED state (see RFC2960 [RFC2960] section 6.4.1 for details). 829 4.1.1. Congestion Control of ASCONF Chunks 831 In defining the ASCONF Chunk transfer procedures, it is essential 832 that these transfers MUST NOT cause congestion within the network. 833 To achieve this, we place these restrictions on the transfer of 834 ASCONF Chunks: 836 C1) One and only one SCTP packet holding ASCONF Chunk(s) MAY be in 837 transit and unacknowledged at any one time. If a sender, after 838 sending an ASCONF chunk, decides it needs to transfer another 839 ASCONF Chunk, it MUST wait until the ASCONF-ACK Chunk returns from 840 the previous ASCONF Chunk before sending a subsequent ASCONF. 841 Note: this restriction binds each side, so at any time two ASCONF 842 may be in-transit on any given association (one sent from each 843 endpoint). However when an ASCONF Chunk is retransmitted due to a 844 time-out, the additional held ASCONF Chunks can be bundled into 845 the retransmission packet as described in Section 4.5. 847 C2) An ASCONF Chunk may be bundled with any other chunk type 848 including other ASCONF Chunks. If bundled with other ASCONF 849 Chunks, the chunks MUST appear in sequential order with respect to 850 their Serial Number. 852 C3) An ASCONF-ACK Chunk may be bundled with any other chunk type 853 including other ASCONF-ACK Chunks. If bundled with other ASCONF- 854 ACK Chunks, the chunks MUST appear in sequential order with 855 respect to their Serial Number. 857 C4) Both ASCONF and ASCONF-ACK Chunks MUST NOT be sent in any SCTP 858 state except ESTABLISHED, SHUTDOWN-PENDING, SHUTDOWN-RECEIVED and 859 SHUTDOWN-SENT. 861 C5) An ASCONF Chunk and an ASCONF-ACK Chunk SHOULD not be larger 862 than the path MTU. 864 If the sender of an ASCONF Chunk receives an Operational Error 865 indicating that the ASCONF Chunk type is not understood, then the 866 sender MUST NOT send subsequent ASCONF Chunks to the peer. The 867 endpoint should also inform the upper layer application that the peer 868 endpoint does not support any of the extensions detailed in this 869 document. 871 4.2. Upon reception of an ASCONF Chunk. 873 When an endpoint receives an ASCONF Chunk from the remote peer 874 special procedures MAY be needed to identify the association the 875 ASCONF Chunk is associated with. To properly find the association 876 the following procedures should be followed: 878 D1) Use the source address and port number of the sender to attempt 879 to identify the association (i.e. use the same method defined in 880 RFC2960 [RFC2960] used for all other SCTP Chunks). If found 881 proceed to rule D4. 883 D2) If the association is not found, use the address found in the 884 Address Parameter TLV combined with the port number found in the 885 SCTP common header. If found proceed to rule D4. 887 D2-ext) If more than one ASCONF Chunks are packed together, use the 888 address found in the ASCONF Address Parameter TLV of the each of 889 the subsequent ASCONF Chunks. If found, proceed to rule D4. 891 D3) If neither D1, D2 nor D2-ext locates the association, treat the 892 chunk as an Out Of The Blue packet as defined in RFC2960 893 [RFC2960]. 895 D4) Follow the normal rules to validate the SCTP verification tag 896 found in RFC2960 [RFC2960]. 898 After identification and verification of the association, the 899 following should be performed to properly process the ASCONF Chunk: 900 E1) If the value found in the serial number of the ASCONF Chunk is 901 equal to the ('Peer-Serial-Number' + 1) and the Serial Number of 902 the ASCONF Chunk is the first in the SCTP Packet, the endpoint MAY 903 clean any old cached ASCONF-ACK up to the 'Peer-Serial-Number' and 904 then proceed to rule E4. 906 E1-ext If the value found in the serial number of the ASCONF Chunk 907 is equal to the ('Peer-Serial-Number' + 1) and the ASCONF chunk is 908 NOT the first Serial Number in the SCTP packet proceed to rule E4 909 but do NOT clear any cached ASCONF-ACK or state information. 911 E2) If the value found in the serial number is less than the ('Peer- 912 Serial-Number' + 1), simply skip to the next ASCONF, and include 913 in the outbound response packet any previously cached ASCONF-ACK 914 response that was sent and saved that matches the serial number of 915 the ASCONF. Note: it is possible that no cached ASCONF-ACK Chunk 916 exists. This will occur when an older ASCONF arrives out of 917 order. In such a case the receiver should skip the ASCONF Chunk 918 and not include ASCONF-ACK Chunk for that chunk. 920 E3) Then, process each ASCONF one by one as above while the Serial 921 Number of the ASCONF is less than the ('Peer-Serial-Number' + 1). 923 E4) When the serial number matches the next one expected, process 924 the ASCONF as described below and after processing the ASCONF 925 Chunk, append an ASCONF-ACK Chunk to the response packet and cache 926 a copy of it (in the event it later needs to be retransmitted). 928 V1) Process the TLVs contained within the Chunk performing the 929 appropriate actions as indicated by each TLV type. The TLVs 930 MUST be processed in order within the Chunk. For example, if 931 the sender puts 3 TLVs in one chunk, the first TLV (the one 932 closest to the Chunk Header) in the Chunk MUST be processed 933 first. The next TLV in the chunk (the middle one) MUST be 934 processed second and finally the last TLV in the Chunk MUST be 935 processed last. 937 V2) In processing the chunk, the receiver should build a response 938 message with the appropriate error TLVs, as specified in the 939 Parameter type bits for any ASCONF Parameter it does not 940 understand. To indicate an unrecognized parameter, cause type 941 8 as defined in the ERROR in 3.3.10.8 of RFC2960 [RFC2960] 942 should be used. The endpoint may also use the response to 943 carry rejections for other reasons such as resource shortages 944 etc, using the Error Cause TLV and an appropriate error 945 condition. 947 Note: a positive response is implied if no error is indicated 948 by the sender. 949 V3) All responses MUST copy the ASCONF-Request Correlation ID 950 field received in the ASCONF parameter, from the TLV being 951 responded to, into the ASCONF-Request Correlation ID field in 952 the response parameter. 954 V4) After processing the entire Chunk, the receiver of the ASCONF 955 MUST queue the response ASCONF-ACK Chunk for transmission after 956 the rest of the SCTP packet has been processed. This allows 957 the ASCONF-ACK Chunk to be bundled with other ASCONF-ACK Chunks 958 as well as any additional responses e.g. a SACK Chunk. 960 V5) Update the 'Peer-Serial-Number' to the value found in the 961 serial number field. 963 E5) Otherwise, the ASCONF Chunk is discarded since it must be either 964 a stale packet or from an attacker. A receiver of such a packet 965 MAY log the event for security purposes. 967 E6) When all ASCONF Chunks are processed for this SCTP packet, send 968 back the accumulated single response packet with all of the 969 ASCONF-ACK Chunks. The destination address of the SCTP packet 970 containing the ASCONF-ACK Chunks MUST be the source address of the 971 SCTP packet that held the ASCONF Chunks. 973 E7) While processing the ASCONF Chunks in the SCTP packet, if the 974 response packet will exceed the PMTU of the return path, the 975 receiver MUST stop adding addtional ASCONF-ACK's into the response 976 packet but MUST continue to process all of the ASCONF Chunks, 977 saving ASCONF-ACK Chunk responses in its cached copy. The sender 978 of the ASCONF Chunk will later retransmit the ASCONF Chunks that 979 were not responded to, at which time the cached copies of the 980 responses that would NOT fit in the PMTU can be sent to the peer. 982 Note: These rules have been presented with the assumption that the 983 implementation is caching old ASCONF-ACK's in case of loss of SCTP 984 packets in the ACK path. It is allowable for an implementation to 985 maintain this state in another form it deems appropriate, as long as 986 that form results in the same ASCONF-ACK sequences being returned to 987 the peer as outlined above. 989 4.3. General rules for address manipulation 991 When building TLV parameters for the ASCONF Chunk that will add or 992 delete IP addresses the following rules should be applied: 994 F0) If an endpoint receives an ASCONF-ACK that is greater than or 995 equal to the next serial number to be used but no ASCONF Chunk is 996 outstanding the endpoint MUST ABORT the association. Note: that a 997 sequence number is greater than if it is no more than 2^^31-1 998 larger than the current sequence number (using serial arithmetic). 1000 F1) When adding an IP address to an association, the IP address is 1001 NOT considered fully added to the association until the ASCONF-ACK 1002 arrives. This means that until such time as the ASCONF containing 1003 the add is acknowledged the sender MUST NOT use the new IP address 1004 as a source for ANY SCTP packet except on carrying an ASCONF 1005 Chunk. The receiver of the add IP address request may use the 1006 address as a destination immediately. The receiver MUST use the 1007 path verification procedure for the added address before using 1008 that address. The receiver MUST NOT send packets to the new 1009 address except for the corresponding ASCONF-ACK Chunk or HEARTBEAT 1010 Chunks for path verification before the new path is verified. If 1011 the ASCONF-ACK is sent to the new address it MAY be bundled with 1012 the HEARTBEAT chunk for path verification. 1014 F2) After the ASCONF-ACK of an IP address add arrives, the endpoint 1015 MAY begin using the added IP address as a source address for any 1016 type of SCTP chunk. 1018 F3a) If an endpoint receives an Error Cause TLV indicating that the 1019 IP address Add or IP address Deletion parameters was not 1020 understood, the endpoint MUST consider the operation failed and 1021 MUST NOT attempt to send any subsequent Add or Delete requests to 1022 the peer. 1024 F3b) If an endpoint receives an Error Cause TLV indicating that the 1025 IP address Set Primary IP Address parameter was not understood, 1026 the endpoint MUST consider the operation failed and MUST NOT 1027 attempt to send any subsequent Set Primary IP Address requests to 1028 the peer. 1030 F4) When deleting an IP address from an association, the IP address 1031 MUST be considered a valid destination address for the reception 1032 of SCTP packets until the ASCONF-ACK arrives and MUST NOT be used 1033 as a source address for any subsequent packets. This means that 1034 any datagrams that arrive before the ASCONF-ACK destined to the IP 1035 address being deleted MUST be considered part of the current 1036 association. One special consideration is that ABORT Chunks 1037 arriving destined to the IP address being deleted MUST be ignored 1038 (see Section 4.3.1 for further details). 1040 F5) An endpoint MUST NOT delete its last remaining IP address from 1041 an association. In other words if an endpoint is NOT multi-homed 1042 it MUST NOT use the delete IP address without an add IP address 1043 preceding the delete parameter in the ASCONF Chunk. Or if an 1044 endpoint sends multiple requests to delete IP addresses it MUST 1045 NOT delete all of the IP addresses that the peer has listed for 1046 the requester. 1048 F6) An endpoint MUST NOT set an IP header source address for an SCTP 1049 packet holding the ASCONF Chunk to be the same as an address being 1050 deleted by the ASCONF Chunk. 1052 F7) If a request is received to delete the last remaining IP address 1053 of a peer endpoint, the receiver MUST send an Error Cause TLV with 1054 the error cause set to the new error code 'Request to Delete Last 1055 Remaining IP Address'. The requested delete MUST NOT be performed 1056 or acted upon, other than to send the ASCONF-ACK. 1058 F8) If a request is received to delete an IP address which is also 1059 the source address of the IP packet which contained the ASCONF 1060 chunk, the receiver MUST reject this request. To reject the 1061 request the receiver MUST send an Error Cause TLV set to the new 1062 error code 'Request to Delete Source IP Address' (unless Rule F5 1063 has also been violated, in which case the error code 'Request to 1064 Delete Last Remaining IP Address' is sent). 1066 F9) If an endpoint receives an ADD IP address request and does not 1067 have the local resources to add this new address to the 1068 association, it MUST return an Error Cause TLV set to the new 1069 error code 'Operation Refused Due to Resource Shortage'. 1071 F10) If an endpoint receives an 'Out of Resource' error in response 1072 to its request to ADD an IP address to an association, it must 1073 either ABORT the association or not consider the address part of 1074 the association. In other words if the endpoint does not ABORT 1075 the association, it must consider the add attempt failed and NOT 1076 use this address since its peer will treat SCTP packets destined 1077 to the address as Out Of The Blue packets. 1079 F11) When an endpoint receiving an ASCONF to add an IP address sends 1080 an 'Out of Resource' in its response, it MUST also fail any 1081 subsequent add or delete requests bundled in the ASCONF. The 1082 receiver MUST NOT reject an ADD and then accept a subsequent 1083 DELETE of an IP address in the same ASCONF Chunk. In other words, 1084 once a receiver begins failing any ADD or DELETE request, it must 1085 fail all subsequent ADD or DELETE requests contained in that 1086 single ASCONF. 1088 F12) When an endpoint receives a request to delete an IP address 1089 that is the current primary address, it is an implementation 1090 decision as to how that endpoint chooses the new primary address. 1092 F13) When an endpoint receives a valid request to DELETE an IP 1093 address the endpoint MUST consider the address no longer as part 1094 of the association. It MUST NOT send SCTP packets for the 1095 association to that address and it MUST treat subsequent packets 1096 received from that address as Out Of The Blue. 1098 During the time interval between sending out the ASCONF and 1099 receiving the ASCONF-ACK it MAY be possible to receive DATA Chunks 1100 out of order. The following examples illustrate these problems: 1102 Endpoint-A Endpoint-Z 1103 ---------- ---------- 1104 ASCONF[Add-IP:X]------------------------------> 1105 /--ASCONF-ACK 1106 / 1107 /--------/---New DATA: 1108 / / Destination 1109 <-------------------/ / IP:X 1110 / 1111 <--------------------------/ 1113 In the above example we see a new IP address (X) being added to the 1114 Endpoint-A. However due to packet re-ordering in the network a new 1115 DATA chunk is sent and arrives at Endpoint-A before the ASCONF-ACK 1116 confirming the add of the address to the association. 1118 A similar problem exists with the deletion of an IP address as 1119 follows: 1121 Endpoint-A Endpoint-Z 1122 ---------- ---------- 1123 /------------New DATA: 1124 / Destination 1125 / IP:X 1126 ASCONF [DEL-IP:X]---------/----------------> 1127 <-----------------/------------------ASCONF-ACK 1128 / 1129 / 1130 <-------------/ 1132 In this example we see a DATA chunk destined to the IP:X (which is 1133 about to be deleted) arriving after the deletion is complete. For 1134 the ADD case an endpoint SHOULD consider the newly adding IP address 1135 valid for the association to receive data from during the interval 1136 when awaiting the ASCONF-ACK. The endpoint MUST NOT source data from 1137 this new address until the ASCONF-ACK arrives but it may receive out 1138 of order data as illustrated and MUST NOT treat this data as an OOTB 1139 datagram (please see RFC2960 [RFC2960] section 8.4). It MAY drop the 1140 data silently or it MAY consider it part of the association but it 1141 MUST NOT respond with an ABORT. 1143 For the DELETE case, an endpoint MAY respond to the late arriving 1144 DATA packet as an OOTB datagram or it MAY hold the deleting IP 1145 address for a small period of time as still valid. If it treats the 1146 DATA packet as an OOTB the peer will silently discard the ABORT 1147 (since by the time the ABORT is sent the peer will have removed the 1148 IP address from this association). If the endpoint elects to hold 1149 the IP address valid for a period of time, it MUST NOT hold it valid 1150 longer than 2 RTO intervals for the destination being removed. 1152 4.3.1. A special case for OOTB ABORT Chunks 1154 Another case worth mentioning is illustrated below: 1156 Endpoint-A Endpoint-Z 1157 ---------- ---------- 1159 New DATA:------------\ 1160 Source IP:X \ 1161 \ 1162 ASCONF-REQ[DEL-IP:X]----\------------------> 1163 \ /---------ASCONF-ACK 1164 \ / 1165 \----/-----------> OOTB 1166 (Ignored <---------------------/-------------ABORT 1167 by rule D4) / 1168 <---------------------/ 1170 For this case, during the deletion of an IP address, an Abort MUST be 1171 ignored if the destination address of the Abort message is that of a 1172 destination being deleted. 1174 4.3.2. A special case for changing an address. 1176 In some instances the sender may only have one IP address in an 1177 association that is being renumbered. When this occurs, the sender 1178 may not be able to send to the peer the appropriate ADD/DELETE pair 1179 and use the old address as a source in the IP header. For this 1180 reason the sender MUST fill in the Address Parameter field with an 1181 address that is part of the association (in this case the one being 1182 deleted). This will allow the receiver to locate the association 1183 without using the source address found in the IP header. 1185 The receiver of such a chunk MUST always first use the source address 1186 found in the IP header in looking up the association. The receiver 1187 should attempt to use the address found in the Address Bytes field 1188 only if the lookup fails using the source address from the IP header. 1189 The receiver MUST reply to the source address of the packet in this 1190 case which is the new address that was added by the ASCONF (since the 1191 old address is no longer a part of the association after processing). 1193 4.4. Setting of the primary address 1195 A sender of this option may elect to send this combined with a 1196 deletion or addition of an address. A sender SHOULD only send a set 1197 primary request to an address that is already considered part of the 1198 association. In other words if a sender combines a set primary with 1199 an add of a new IP address the set primary will be discarded unless 1200 the add request is to be processed BEFORE the set primary (i.e. it 1201 precedes the set primary). 1203 A request to set primary MAY also appear in an INIT or INIT-ACK 1204 chunk. This can give advice to the peer endpoint as to which of its 1205 addresses the sender of the INIT or INIT-ACK would prefer to be used 1206 as the primary address. 1208 The request to set an address as the primary path is an option the 1209 receiver SHOULD perform. It is considered advice to the receiver of 1210 the best destination address to use in sending SCTP packets (in the 1211 requesters view). If a request arrives that asks the receiver to set 1212 an address as primary that does not exist, the receiver should NOT 1213 honor the request, leaving its existing primary address unchanged. 1215 4.5. Bundling of multiple ASCONFs 1217 In the normal case a single ASCONF is sent in a packet and a single 1218 reply ASCONF-ACK is received. However, in the event of the loss of 1219 an SCTP packet containing either an ASCONF or ASCONF-ACK it is 1220 allowable for a sender to bundle additional ASCONF's in the 1221 retransmission. In bundling multiple ASCONF's the following rules 1222 MUST be followed: 1223 1. Previously transmitted ASCONF Chunks MUST be left unchanged. 1224 2. Each SCTP packet containing ASCONF Chunks MUST be bundled 1225 starting with the smallest ASCONF Serial Number first in the 1226 packet (closest to the Chunk header) and preceeding in sequential 1227 order from lowest to highest ASCONF Serial Number. 1229 3. All ASCONF's within the packet MUST be adjacent to each other 1230 i.e. no other chunk type must seperate the ASCONF's. 1231 4. Each new ASCONF's lookup address MUST be populated as if the 1232 previous ASCONF's had been processed and accepted. 1234 5. Security Considerations 1236 The addition and or deletion of an IP address to an existing 1237 association does provide an additional mechanism by which existing 1238 associations can be hijacked. Therefore this document requires the 1239 use of the authentication mechanism defined in SCTP-AUTH 1240 [I-D.ietf-tsvwg-sctp-auth] to limit the ability of an attacker to 1241 hijack an association. 1243 Hijacking an association by using the addition and deletion of an IP 1244 address is only possible for an attacker who is able to intercept the 1245 initial two packets of the association setup when the SCTP-AUTH 1246 extension is used without pre-shared keys.. If such a threat is 1247 considered a possibility, then the SCTP-AUTH 1248 [I-D.ietf-tsvwg-sctp-auth] extension MUST be used with a 1249 preconfigured shared end-point pair key to mitigate this threat. For 1250 a more detailed analysis see SCTP-AUTH [I-D.ietf-tsvwg-sctp-auth]. 1252 If an SCTP endpoint that supports this extension receives an INIT 1253 that indicates that the peer supports the ASCONF extension but does 1254 NOT support the SCTP-AUTH [I-D.ietf-tsvwg-sctp-auth] extension, the 1255 receiver of such an INIT MUST send an ABORT in response to such an 1256 INIT. Note: that an implementation is allowed to silently discard 1257 such an INIT as an option as well but under NO circumstance is an 1258 implementation allowed to proceed with the association setup by 1259 sending an INIT-ACK in response. 1261 An implementation that receives an INIT-ACK that indicates that the 1262 peer does not support the SCTP-AUTH [I-D.ietf-tsvwg-sctp-auth] 1263 extension MUST NOT send the COOKIE-ECHO to establish the association. 1264 Instead the implementation MUST discard the INIT-ACK and report to 1265 the upper layer user that an association cannot be established 1266 destroying the TCB. 1268 6. IANA considerations 1270 This document defines the following new SCTP parameters, chunks and 1271 errors: 1273 o Two new chunk types, 1274 o Seven parameter types, and 1275 o Five new SCTP error causes. 1277 One of the two new chunk types must come from the range of chunk 1278 types where the upper two bits are one, we recommend 0xC1 but any 1279 other available code point with the upper bits set is also 1280 acceptable. The second chunk type must come from the range where 1281 only the upper bit is set to one. We recommend 0x80 but any other 1282 available code point with the upper bit set is also acceptable. The 1283 suggested chunk types are listed in Table 1. 1285 All but one of the parameter types must come from the range of types 1286 where the upper two bits are set, we recommend 0xC001 - 0xC006, as 1287 specified in this document. The other parameter type must come from 1288 the 0x8000 range, we recommend 0x8008. Note: that for any of these 1289 values a different unique parameter type may be assigned by IANA as 1290 long as the upper bits correspond to the ones specified in this 1291 document. The suggested parameter types are listed in Table 2, Table 1292 3, and Table 4. 1294 The five new error causes can be any value, in this document we have 1295 used 0x0100-0x0104 in an attempt to separate these from the common 1296 ranges of error codes. Any other unassigned values are also 1297 acceptable. The suggested error causes are listed in Table 5. 1299 This document also defines a Adaptation code point. The adaptation 1300 code point is a 32 bit integer that is assigned by IANA through an 1301 IETF Consensus action as defined in RFC2434 [RFC2434]. 1303 7. Acknowledgments 1305 The authors would like to express a special note of thanks to Michael 1306 Ramahlo and Phillip Conrad for there extreme efforts in the early 1307 formation of this draft. 1309 The authors wish to thank Jon Berger, Greg Kendall, Seok Koh, Peter 1310 Lei, John Loughney, Ivan Arias Rodriguez, Renee Revis, Marshall Rose, 1311 Chip Sharp, and Irene Ruengeler for their invaluable comments. 1313 The authors would also like to give special mention to Maria-Carmen 1314 Belinchon and Ian Rytina for there early contributions to this 1315 document and their thoughtful comments. 1317 8. References 1319 [RFC2026] Bradner, S., "The Internet Standards Process -- Revision 1320 3", BCP 9, RFC 2026, October 1996. 1322 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 1323 Requirement Levels", BCP 14, RFC 2119, March 1997. 1325 [RFC2402] Kent, S. and R. Atkinson, "IP Authentication Header", 1326 RFC 2402, November 1998. 1328 [RFC2434] Narten, T. and H. Alvestrand, "Guidelines for Writing an 1329 IANA Considerations Section in RFCs", BCP 26, RFC 2434, 1330 October 1998. 1332 [RFC2629] Rose, M., "Writing I-Ds and RFCs using XML", RFC 2629, 1333 June 1999. 1335 [RFC2960] Stewart, R., Xie, Q., Morneault, K., Sharp, C., 1336 Schwarzbauer, H., Taylor, T., Rytina, I., Kalla, M., 1337 Zhang, L., and V. Paxson, "Stream Control Transmission 1338 Protocol", RFC 2960, October 2000. 1340 [I-D.ietf-tsvwg-sctp-auth] 1341 Tuexen, M., "Authenticated Chunks for Stream Control 1342 Transmission Protocol (SCTP)", 1343 draft-ietf-tsvwg-sctp-auth-04 (work in progress), 1344 September 2006. 1346 Appendix A. Abstract Address Handling 1348 A.1. General remarks 1350 The following text provides a working definition of the endpoint 1351 notion to discuss address reconfiguration. It is not intended to 1352 restrict implementations in any way, its goal is to provide as set of 1353 definitions only. Using these definitions should make a discussion 1354 about address issues easier. 1356 A.2. Generalized endpoints 1358 A generalized endpoint is a pair of a set of IP addresses and a port 1359 number at any given point of time. The precise definition is as 1360 follows: 1362 A generalized endpoint gE at time t is given by 1363 gE(t) = ({IP1, ..., IPn}, Port) 1365 where {IP1, ..., IPn} is a non empty set of IP addresses. 1367 Please note that the dynamic addition and deletion of IP-addresses 1368 described in this document allows the set of IP-addresses of a 1369 generalized endpoint to be changed at some point of time. The port 1370 number can never be changed. 1372 The set of IP addresses of a generalized endpoint gE at a time t is 1373 defined as 1375 Addr(gE)(t) = {IP1, ..., IPn} 1377 if gE(t) = ({IP1, ..., IPn}, Port) holds at time t. 1379 The port number of a generalized endpoint gE is defined as 1381 Port(gE) = Port 1383 if gE(t) = ({IP1, ..., IPn}, Port) holds at time t. 1385 There is one fundamental rule which restricts all generalized 1386 endpoints: 1388 For two different generalized endpoints gE' and gE'' with the same 1389 port number Port(gE') = Port(gE'') the address sets Addr(gE')(t) and 1390 Addr(gE'')(t) must be disjoint at every point of time. 1392 A.3. Associations 1394 Associations consists of two generalized endpoints and the two 1395 address sets known by the peer at any time. The precise definition 1396 is as follows: 1398 An association A between to different generalized endpoints gE' and 1399 gE'' is given by 1401 A = (gE', S', gE'', S'') 1403 where S'(t) and S''(t) are set of addresses at any time t such that 1404 S'(t) is a non-empty subset of Addr(gE')(t) and S''(t) is a non-empty 1405 subset of Addr(gE'')(t). 1407 If A = (gE', S', gE'', S'') is an association between the generalized 1408 endpoints gE' and gE'' the following notion is used: 1410 Addr(A, gE') = S' and Addr(A, gE'') = S''. 1412 If the dependency on time is important the notion Addr(A, gE')(t) = 1413 S'(t) will be used. 1415 If A is an association between gE' and gE'' then Addr(A, gE') is the 1416 subset of IP addresses of gE' which is known by gE'' and used by gE'. 1418 Association establishment between gE' and gE'' can be seen as: 1420 1. gE' and gE'' do exist before the association. 1421 2. If an INIT has to be send from gE' to gE'' address scoping rules 1422 and other limitations are applied to calculate the subset S' from 1423 Addr(gE'). The addresses of S' are included in the INIT chunk. 1424 3. If an INIT-ACK has to be send from gE'' to gE' address scoping 1425 rules and other limitations are applied to calculate the subset 1426 S'' from Addr(gE''). The addresses of S'' are included in the 1427 INIT-ACK chunk. 1428 4. After the handshake the association A = (gE', S', gE'', S'') has 1429 been established. 1430 5. Right after the association establishment Addr(A, gE') and 1431 Addr(A, gE'') are the addresses which have been seen on the wire 1432 during the handshake. 1434 A.4. Relationship with RFC 2960 1436 RFC2960 [RFC2960] defines the notion of an endpoint. This subsection 1437 will show that these endpoints are also (special) generalized 1438 endpoints. 1440 RFC2960 [RFC2960] has no notion of address scoping or other address 1441 handling limitations and provides no mechanism to change the 1442 addresses of an endpoint. 1444 This means that an endpoint is simply a generalized endpoint which 1445 does not depend on the time. Neither the Port nor the address list 1446 changes. 1448 During association setup no address scoping rules or other 1449 limitations will be applied. This means that for an association A 1450 between two endpoints gE' and gE'' the following is true: 1452 Addr(A, gE') = Addr(gE') and Addr(A, gE'') = Addr(gE''). 1454 A.5. Rules for address manipulation 1456 The rules for address manipulation can now be stated in a simple way: 1457 1. An address can be added to a generalized endpoint gE only if this 1458 address is not an address of a different generalized endpoint 1459 with the same port number. 1461 2. An address can be added to an association A with generalized 1462 endpoint gE if it has been added to the generalized endpoint gE 1463 first. This means that the address must be an element of 1464 Addr(gE) first and then it can become an element of Addr(A, gE). 1465 But this is not necessary. If the association does not allow the 1466 reconfiguration of the addresses only Addr(gE) can be modified. 1467 3. An address can be deleted from an association A with generalized 1468 endpoint gE as long as Addr(A, gE) stays non-empty. 1469 4. An address can be deleted from an generalized endpoint gE only if 1470 it has been removed from all associations having gE as a 1471 generalized endpoint. 1473 These rules simply make sure that the rules for the endpoints and 1474 associations given above are always fulfilled. 1476 Authors' Addresses 1478 Randall R. Stewart 1479 Cisco Systems, Inc. 1480 4875 Forest Drive 1481 Suite 200 1482 Columbia, SC 29206 1483 US 1485 Phone: 1486 Email: rrs@cisco.com 1488 Qiaobing Xie 1489 Motorola, Inc. 1490 1501 W. Shure Drive, #2309 1491 Arlington Heights, IL 60004 1492 USA 1494 Phone: +1-847-632-3028 1495 Email: qxie1@email.mot.com 1497 Michael Tuexen 1498 Univ. of Applied Sciences Muenster 1499 Stegerwaldstr. 39 1500 48565 Steinfurt 1501 Germany 1503 Email: tuexen@fh-muenster.de 1504 Shin Maruyama 1505 Kyoto University 1506 Yoshida-Honmachi 1507 Sakyo-ku 1508 Kyoto, Kyoto 606-8501 1509 JAPAN 1511 Phone: +81-75-753-7468 1512 Email: mail@marushin.gr.jp 1514 Masahiro Kozuka 1515 Kyoto University 1516 Yoshida-Honmachi 1517 Sakyo-ku 1518 Kyoto, Kyoto 606-8501 1519 JAPAN 1521 Phone: +81-75-753-7468 1522 Email: ma-kun@kozuka.jp 1524 Full Copyright Statement 1526 Copyright (C) The Internet Society (2006). 1528 This document is subject to the rights, licenses and restrictions 1529 contained in BCP 78, and except as set forth therein, the authors 1530 retain all their rights. 1532 This document and the information contained herein are provided on an 1533 "AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS 1534 OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY AND THE INTERNET 1535 ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS OR IMPLIED, 1536 INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE 1537 INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED 1538 WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. 1540 Intellectual Property 1542 The IETF takes no position regarding the validity or scope of any 1543 Intellectual Property Rights or other rights that might be claimed to 1544 pertain to the implementation or use of the technology described in 1545 this document or the extent to which any license under such rights 1546 might or might not be available; nor does it represent that it has 1547 made any independent effort to identify any such rights. Information 1548 on the procedures with respect to rights in RFC documents can be 1549 found in BCP 78 and BCP 79. 1551 Copies of IPR disclosures made to the IETF Secretariat and any 1552 assurances of licenses to be made available, or the result of an 1553 attempt made to obtain a general license or permission for the use of 1554 such proprietary rights by implementers or users of this 1555 specification can be obtained from the IETF on-line IPR repository at 1556 http://www.ietf.org/ipr. 1558 The IETF invites any interested party to bring to its attention any 1559 copyrights, patents or patent applications, or other proprietary 1560 rights that may cover technology that may be required to implement 1561 this standard. Please address the information to the IETF at 1562 ietf-ipr@ietf.org. 1564 Acknowledgment 1566 Funding for the RFC Editor function is provided by the IETF 1567 Administrative Support Activity (IASA).