idnits 2.17.1 draft-ietf-sipclf-format-11.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 : ---------------------------------------------------------------------------- -- The document has examples using IPv4 documentation addresses according to RFC6890, but does not use any IPv6 documentation addresses. Maybe there should be IPv6 examples, too? Miscellaneous warnings: ---------------------------------------------------------------------------- == The copyright year in the IETF Trust and authors Copyright Line does not match the current year == The document seems to use 'NOT RECOMMENDED' as an RFC 2119 keyword, but does not include the phrase in its RFC 2119 key words list. -- The document date (December 21, 2012) is 4141 days in the past. Is this intentional? Checking references for intended status: Proposed Standard ---------------------------------------------------------------------------- (See RFCs 3967 and 4897 for information about using normative references to lower-maturity documents in RFCs) == Outdated reference: A later version (-13) exists of draft-ietf-sipclf-problem-statement-11 -- Obsolete informational reference (is this intentional?): RFC 2629 (Obsoleted by RFC 7749) -- Obsolete informational reference (is this intentional?): RFC 5226 (Obsoleted by RFC 8126) Summary: 0 errors (**), 0 flaws (~~), 3 warnings (==), 4 comments (--). Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 2 SIPCLF G. Salgueiro 3 Internet-Draft Cisco Systems 4 Intended status: Standards Track V. Gurbani 5 Expires: June 24, 2013 Bell Labs, Alcatel-Lucent 6 A. B. Roach 7 Tekelec 8 December 21, 2012 10 Format for the Session Initiation Protocol (SIP) Common Log Format (CLF) 11 draft-ietf-sipclf-format-11 13 Abstract 15 The SIPCLF Workgroup has defined a common log format framework for 16 Session Initiation Protocol (SIP) servers. This common log format 17 mimics the successful event logging format found in well-known web 18 servers like Apache and web proxies like Squid. This document 19 proposes an indexed text encoding format for the SIP Common Log 20 Format (CLF) that retains the key advantages of a text-based format, 21 while significantly increasing processing performance over a purely 22 text-based implementation. This file format adheres to the SIP CLF 23 information model and provides an effective encoding scheme for all 24 mandatory and optional fields that appear in a SIP CLF record. 26 Status of this Memo 28 This Internet-Draft is submitted in full conformance with the 29 provisions of BCP 78 and BCP 79. 31 Internet-Drafts are working documents of the Internet Engineering 32 Task Force (IETF). Note that other groups may also distribute 33 working documents as Internet-Drafts. The list of current Internet- 34 Drafts is at http://datatracker.ietf.org/drafts/current/. 36 Internet-Drafts are draft documents valid for a maximum of six months 37 and may be updated, replaced, or obsoleted by other documents at any 38 time. It is inappropriate to use Internet-Drafts as reference 39 material or to cite them other than as "work in progress." 41 This Internet-Draft will expire on June 24, 2013. 43 Copyright Notice 45 Copyright (c) 2012 IETF Trust and the persons identified as the 46 document authors. All rights reserved. 48 This document is subject to BCP 78 and the IETF Trust's Legal 49 Provisions Relating to IETF Documents 50 (http://trustee.ietf.org/license-info) in effect on the date of 51 publication of this document. Please review these documents 52 carefully, as they describe your rights and restrictions with respect 53 to this document. Code Components extracted from this document must 54 include Simplified BSD License text as described in Section 4.e of 55 the Trust Legal Provisions and are provided without warranty as 56 described in the Simplified BSD License. 58 Table of Contents 60 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 61 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3 62 3. Document Conventions . . . . . . . . . . . . . . . . . . . . . 4 63 4. Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 64 4.1. Index Pointers . . . . . . . . . . . . . . . . . . . . . . 8 65 4.2. Mandatory Fields . . . . . . . . . . . . . . . . . . . . . 10 66 4.3. SIP CLF Encoding and Character Escaping Requirements . . . 14 67 4.4. Optional Fields . . . . . . . . . . . . . . . . . . . . . 15 68 5. Example SIP CLF Record . . . . . . . . . . . . . . . . . . . . 24 69 6. Text Tool Considerations . . . . . . . . . . . . . . . . . . . 26 70 7. Security Considerations . . . . . . . . . . . . . . . . . . . 26 71 8. Operational Guidance . . . . . . . . . . . . . . . . . . . . . 26 72 9. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 26 73 9.1. SIP CLF Version . . . . . . . . . . . . . . . . . . . . . 27 74 9.2. SIP CLF Transport Flag . . . . . . . . . . . . . . . . . . 27 75 10. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 28 76 11. References . . . . . . . . . . . . . . . . . . . . . . . . . . 28 77 11.1. Normative References . . . . . . . . . . . . . . . . . . . 28 78 11.2. Informative References . . . . . . . . . . . . . . . . . . 29 79 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 30 81 1. Introduction 83 The extensive list of benefits and the widespread adoption of the 84 Apache Common Log Format (CLF) has prompted the development of an 85 analogous event logging mechanism for the Session Initiation Protocol 86 [RFC3261] (SIP). Implementing a logging scheme for SIP is a 87 considerable challenge. This is due in part to the fact that the 88 behavior of a SIP entity is more complex as compared to an HTTP 89 entity. Additionally, there are shortcomings to the purely text- 90 based HTTP Common Log Format that need to be addressed in order to 91 allow for real-time inspection of SIP log files 92 [I-D.ietf-sipclf-problem-statement]. Experience with Apache Common 93 Log Format has shown that dealing with large quantities of log data 94 can be very processor intensive, as doing so necessarily requires 95 reading and parsing every byte in the log file(s) of interest. 97 An implementation independent framework for the SIP CLF has been 98 defined in [I-D.ietf-sipclf-problem-statement]. This memo describes 99 an indexed text file format for logging SIP messages received and 100 sent by SIP clients, servers, and proxies that adheres to the 101 information model presented in Section 8 of 102 [I-D.ietf-sipclf-problem-statement]. This document defines a format 103 that is no more difficult to generate by logging entities than 104 standard (i.e., non-indexed) text log formats, while being radically 105 faster to process. In particular, the format is optimized for both 106 rapidly scanning through log records, as well as quickly locating 107 commonly accessed data fields. 109 Further, the format proposed by this document retains the key 110 advantage of being human readable and able to be processed using the 111 various Unix text processing tools, such as sed, awk, perl, cut, and 112 grep. 114 2. Terminology 116 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 117 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this 118 document are to be interpreted as described in [RFC2119]. 120 "SHOULD", "SHOULD NOT", "RECOMMENDED", and "NOT RECOMMENDED" are 121 appropriate when valid exceptions to a general requirement are known 122 to exist or appear to exist, and it is infeasible or impractical to 123 enumerate all of them. However, they should not be interpreted as 124 permitting implementors to fail to implement the general requirement 125 when such failure would result in interoperability failure. 127 [RFC3261] defines additional terms used in this document that are 128 specific to the SIP domain such as "proxy"; "registrar"; "redirect 129 server"; "user agent server" or "UAS"; "user agent client" or "UAC"; 130 "back-to-back user agent" or "B2BUA"; "dialog"; "transaction"; 131 "server transaction". 133 This document uses the term "SIP Server" that is defined to include 134 the following SIP entities: user agent server, registrar, redirect 135 server, a SIP proxy in the role of user agent server, and a B2BUA in 136 the role of a user agent server. 138 The reader is expected to be familiar with the terminology and 139 concepts defined in [I-D.ietf-sipclf-problem-statement]. 141 3. Document Conventions 143 This document defines the logging syntax for the SIP CLF. This 144 syntax is demonstrated through the use of various examples. The 145 formatting described here does not permit these examples to be 146 unambiguously rendered due to the constraints imposed by the 147 formatting rules for RFCs. To avoid ambiguity and to meet the RFC 148 layout requirements this document uses the markup 149 convention established in [RFC4475]. 151 For the sake of clarity and completeness, the entire text defining 152 this markup convention from Section 2.1 of [RFC4475] is quoted below: 154 Several of these examples contain unfolded lines longer than 72 155 characters. These are captured between tags. The 156 single unfolded line is reconstructed by directly concatenating 157 all lines appearing between the tags (discarding any line feeds or 158 carriage returns). There will be no whitespace at the end of 159 lines. Any whitespace appearing at a fold-point will appear at 160 the beginning of a line. 162 The following represent the same string of bits: 164 Header-name: first value, reallylongsecondvalue, third value 166 167 Header-name: first value, 168 reallylongsecondvalue 169 , third value 170 172 173 Header-name: first value, 174 reallylong 175 second 176 value, 177 third value 178 180 Note that this is NOT SIP header-line folding, where different 181 strings of bits have equivalent meaning. 183 The IP addresses used in the examples in this document correspond to 184 the documentation address block 192.0.2.0/24 (TEST-NET-1) as 185 described in [RFC5737]. 187 4. Format 189 The Common Log Format for the Session Initiation Protocol 190 [I-D.ietf-sipclf-problem-statement] defines an information model to 191 which this logging format format adheres, and Section 8.1 of that 192 document defines all the mandatory information model elements. 194 This document defines the format of SIP CLF records as follows: 196 0 7 8 15 16 23 24 31 197 +-----------+-----------+-----------+-----------+ 198 | Version | Record Length | 0 - 3 199 +-----------+-----------+-----------+-----------+ 200 | Record Length (cont) | 0x2C | 4 - 7 201 +-----------+-----------+-----------+-----------+ 202 | CSeq Pointer (Hex) | 8 - 11 203 +-----------+-----------+-----------+-----------+ 204 | Response Status-Code Pointer (Hex) | 12 - 15 205 +-----------+-----------+-----------+-----------+ 206 | R-URI Pointer (Hex) | 16 - 19 207 +-----------+-----------+-----------+-----------+ 208 | Destination IP address:port Pointer (Hex) | 20 - 23 209 +-----------+-----------+-----------+-----------+ 210 | Source IP address:port Pointer (Hex) | 24 - 27 211 +-----------+-----------+-----------+-----------+ 212 | To URI Pointer (Hex) | 28 - 31 213 +-----------+-----------+-----------+-----------+ 214 | To Tag Pointer (Hex) | 32 - 35 215 +-----------+-----------+-----------+-----------+ 216 | From URI Pointer (Hex) | 36 - 39 217 +-----------+-----------+-----------+-----------+ 218 | From Tag Pointer (Hex) | 40 - 43 219 +-----------+-----------+-----------+-----------+ 220 | Call-Id Pointer (Hex) | 44 - 47 221 +-----------+-----------+-----------+-----------+ 222 | Server-Txn Pointer (Hex) | 48 - 51 223 +-----------+-----------+-----------+-----------+ 224 | Client-Txn Pointer (Hex) | 52 - 55 225 +-----------+-----------+-----------+-----------+ 226 | Optional Fields Start Pointer (Hex) | 56 - 59 227 +-----------+-----------+-----------+-----------+ 228 | 0x0A | | 60 - 63 229 +-----------+ + 230 | Timestamp | 64 - 67 231 + +-----------+ 232 | | 0x2E | 68 - 71 233 +-----------+-----------+-----------+-----------+ 234 | Fractional Seconds | 0x09 | 72 - 75 235 +-----------+-----------+-----------+-----------+ 236 | Flags Field | 76 - 79 237 +-----------+-----------+-----------+-----------+ 238 |Flag (cont)| 0x09 | | 80 - 83 239 |-----------+-----------+ | 240 | | 241 | | 242 | Mandatory Fields (variable length) | 243 | | 244 | | 245 +-----------+-----------+-----------+-----------+ 246 | 0x09 | Tag | 0x40 |\ 247 +-----------+-----------+-----------+-----------+ \ 248 | Vendor-ID | \ 249 +-----------+-----------+-----------+-----------+ \ 250 | Vendor-ID (cont) | \ Repeated 251 +-----------+-----------+-----------+-----------+ \ as many 252 | 0x2C | Length (Hex) | > times as 253 +-----------+-----------+-----------+-----------+ / necessary 254 | Len (cont)| 0x2C | BEB | 0x2C | / 255 +-----------+-----------+-----------------------| / 256 | | / 257 | Value (variable length) | / 258 | |/ 259 +-----------+-----------+-----------+-----------+ 260 | 0x0A | 261 +-----------+ 263 Figure 1: SIP Common Log Format 265 The format presented in Figure 1 is for a single SIP CLF log entry. 266 While there is no actual subdivision in practice, this format can be 267 logically subdivided into the following three distinct components: 269 1. Index Pointers - The first 60-bytes of this format. This 270 portion is metadata, primarily composed of a list of pointers that 271 indicate the beginning of both the variable length mandatory and 272 optional fields that are logged as part of this record. These 273 pointers are implemented as a mechanism to improve processing of 274 these records and to allow a reader to expeditiously skip directly 275 to the desired field without unnecessarily going through the 276 entire record. This logical subdivision within the SIP CLF format 277 will be referenced in this document with the tag. 278 A 0x0A (LF character) delimits from the next 279 logical grouping. 281 2. Mandatory Fields - The next logical grouping in this format is 282 a tab (0x09) delimited listing of the mandatory fields as 283 described in Section 8.1 of [I-D.ietf-sipclf-problem-statement] 284 and in the order listed in . This logical 285 subdivision within the SIP CLF format will be referenced in this 286 document with the tag. 288 3. Optional Fields - The last logical component MAY be present as 289 it is an OPTIONAL extension to the SIP CLF format. Its purpose is 290 to provide flexibility to the developer of this SIP CLF to log any 291 desired fields not included in . This includes 292 SIP bodies and any vendor-specific extensions. This logical 293 subdivision within the SIP CLF format will be referenced in this 294 document with the tag. 296 This logical structure of the SIP CLF record format can be 297 graphically represented as shown in Figure 2 below: 299 300 301 303 Figure 2: Logical Structure of the SIP CLF Record 305 Note that Figure 1 and Figure 2 plus the terminating line-feed (0x0A) 306 at the end of the SIP CLF record are different representations of the 307 same format but are functionally equivalent. The representation of 308 this format is a two line record where the metadata 309 is on one line and the actual data like and 310 (if present) is on another. 312 In the following sections note that indications of "hexadecimal 313 encoded" indicate values that are always unsigned and are to be 314 written out in human-readable base-16 numbers using the UTF-8 315 characters 0x30 through 0x39 ('0' through '9') and 0x41 through 0x46 316 ('A' through 'F'). Similarly, indications of "decimal encoded" 317 indicate that the value is to be written out in human readable 318 base-10 number using the UTF-8 characters 0x30 through 0x39 ('0' 319 through '9'). In both encodings, numbers always take up the number 320 of bytes indicated, and are padded on the left with UTF-8 '0' (zero) 321 characters to fill the entire space. 323 4.1. Index Pointers 324 The portion of the SIP CLF record (shown in Figure 3) 325 is a 60-byte header that indicates metadata about the record. 327 0 7 8 15 16 23 24 31 328 +-----------+-----------+-----------+-----------+ 329 | Version | Record Length | 0 - 3 330 +-----------+-----------+-----------+-----------+ 331 | Record Length (cont) | 0x2C | 4 - 7 332 +-----------+-----------+-----------+-----------+ 333 | CSeq Pointer (Hex) | 8 - 11 334 +-----------+-----------+-----------+-----------+ 335 | Response Status-Code Pointer (Hex) | 12 - 15 336 +-----------+-----------+-----------+-----------+ 337 | R-URI Pointer (Hex) | 16 - 19 338 +-----------+-----------+-----------+-----------+ 339 | Destination IP address:port Pointer (Hex) | 20 - 23 340 +-----------+-----------+-----------+-----------+ 341 | Source IP address:port Pointer (Hex) | 24 - 27 342 +-----------+-----------+-----------+-----------+ 343 | To URI Pointer (Hex) | 28 - 31 344 +-----------+-----------+-----------+-----------+ 345 | To Tag Pointer (Hex) | 32 - 35 346 +-----------+-----------+-----------+-----------+ 347 | From URI Pointer (Hex) | 36 - 39 348 +-----------+-----------+-----------+-----------+ 349 | From Tag Pointer (Hex) | 40 - 43 350 +-----------+-----------+-----------+-----------+ 351 | Call-Id Pointer (Hex) | 44 - 47 352 +-----------+-----------+-----------+-----------+ 353 | Server-Txn Pointer (Hex) | 48 - 51 354 +-----------+-----------+-----------+-----------+ 355 | Client-Txn Pointer (Hex) | 52 - 55 356 +-----------+-----------+-----------+-----------+ 357 | Optional Fields Start Pointer (Hex) | 56 - 59 358 +-----------+-----------+-----------+-----------+ 360 Figure 3: Index Pointers 362 The fields that make up are described below: 364 Version (1 byte): UTF-8 encoded version for the SIP CLF record. 365 Range of valid values for the Version is from 'A' (0x41) to 'Z' 366 (0x5A). This document uses a Version value of "0x41" ('A'). 368 The value of the SIP CLF Version MUST be incremented for any new 369 SIP CLF specification that changes any part of the SIP CLF record 370 format. The SIP CLF Version values are IANA-assigned 371 (Section 9.1) via the Standards Action method as described in 372 [RFC5226]. 374 Since the version is specified per record it is possible that a 375 SIP CLF log file could contain records with different versions. 376 Under normal operating conditions this is an unlikely occurrence 377 and SHOULD be avoided if possible. 379 Record Length (6 bytes): Hexadecimal encoded total length of this 380 log record, beginning with the "Version" octet and ending with the 381 terminating line-feed. 383 Bytes 8 through 55 contain hexadecimal encoded pointers that point to 384 the starting location of each of the variable-length mandatory 385 fields. Bytes 56 through 59 contain hexadecimal encoded pointer that 386 points to the starting location of the optional fields portion of the 387 SIP CLF record. Note that there are no delimiters between these 388 pointer values -- they are packed together as a single, 52-character 389 hexadecimal encoded string. The "Pointer" fields indicate absolute 390 byte values within the record, and are therefore >=82. They point to 391 the start of the corresponding value within the 392 portion. A description of each of the mandatory fields that these 393 pointer values point to can be found in Section 4.2. 395 Optional Fields Start Pointer: This final pointer indicates the 396 location within the SIP CLF record where the OPTIONAL group of 397 begin, if present. The "Optional Fields Start 398 Pointer" points to the UTF-8 Tab (0x09) character for the first 399 entry in the portion. If the OPTIONAL group of 400 are not implemented, then the "Optional Fields 401 Start Pointer" field MUST point to the terminating line-feed 402 (0x0A) at the end of the SIP CLF record. 404 4.2. Mandatory Fields 405 The portion of the SIP CLF record is shown below: 407 0 7 8 15 16 23 24 31 408 +-----------+-----------+-----------+-----------+ 409 | 0x0A | | 60 - 63 410 +-----------+ + 411 | Timestamp | 64 - 67 412 + +-----------+ 413 | | 0x2E | 68 - 71 414 +-----------+-----------+-----------+-----------+ 415 | Fractional Seconds | 0x09 | 72 - 75 416 +-----------+-----------+-----------+-----------+ 417 | Flags Field | 76 - 79 418 +-----------+-----------+-----------+-----------+ 419 |Flag (cont)| 0x09 | | 80 - 83 420 |-----------+-----------+ | 421 | | 422 | | 423 | Mandatory Fields (variable length) | 424 | | 425 | | 426 +-----------+-----------+-----------+-----------+ 428 Figure 4: Mandatory Fields 430 Following the pointers in , two fixed-length fields 431 are encoded to specify the exact time of the log entry. As before, 432 all fields are completely filled, pre-pending values with '0' 433 characters as necessary. 435 Timestamp (10 bytes): Decimal encoded date and time of the request 436 or response represented as the number of seconds since the Unix 437 epoch (i.e. seconds since midnight, January 1st, 1970, GMT). 439 Fractional Seconds (3 bytes): Decimal encoded fractional seconds 440 portion of the Timestamp field to millisecond accuracy. 442 The combined Timestamp and Fractional Seconds fields are 443 represented in the log file as a UTF-8 encoded string representing 444 the date and time of the request or response represented as the 445 number of seconds and milliseconds since the Unix epoch. The 446 number of milliseconds are separated by a "." (UTF-8 character 447 0x2E) from the number of seconds. 449 Flags Field (5 bytes): 451 byte 1 - Request/Response Flag 453 R = Request 454 r = Response 456 byte 2 - Retransmission Flag 458 O = Original transmission 459 D = Duplicate transmission 460 S = Server is stateless [i.e., retransmissions are not 461 detected] 463 byte 3 - Sent/Received Flag 465 S = Sent message 466 R = Received message 468 byte 4 - Transport Flag 470 The Transport Flag values are IANA-assigned (Section 9.2) via 471 the IETF Review method as described in [RFC5226]. Currently 472 registered values are: 474 U = UDP 475 T = TCP 476 S = SCTP 478 byte 5 - Encryption Flag 480 E = Encrytped message (TLS, DTLS, etc.) 481 U = Unencrypted message 483 After the "Timestamp", "Fractional Seconds" and the "Flags" fields 484 are the values for the mandatory fields specified in Section 8.1 of 485 [I-D.ietf-sipclf-problem-statement], which are described below: 487 CSeq: The Command Sequence header field, including the CSeq number 488 and method name. 490 Response Status-Code: Set to the value of the SIP response status 491 code for responses. Set to a single UTF-8 dash (0x2D) for 492 requests. 494 R-URI: The Request-URI in the start line (mandatory in request), 495 including any URI parameters. 497 Destination IP address:port The IP address of the downstream server 498 and the port number, separated by a single ':'. IPv4 addresses 499 are represented in "dotted decimal" notation as per [RFC1166]. 500 IPv6 addresses are represented using the hexadecimal notation 501 detailed in Section 4 of [RFC5952] (or the special-case mixed 502 hexadecimal and decimal notation detailed in Section 5 of 503 [RFC5952]) and enclosed in square brackets ('[' and ']'). 505 Source IP address:port Source IP address:port The IP address of the 506 upstream client and the port number over which the SIP message was 507 received, separated by a single ':'. IPv4 addresses are 508 represented in "dotted decimal" notation as per [RFC1166]. IPv6 509 addresses are represented using the hexadecimal notation detailed 510 in Section 4 of [RFC5952] (or the special-case mixed hexadecimal 511 and decimal notation detailed in Section 5 of [RFC5952]) and 512 enclosed in square brackets ('[' and ']'). 514 To URI: Value of the URI in the To header field. 516 To Tag: Value of the tag parameter (if present) in the To header 517 field. 519 From URI: Value of the URI in the From header field. 521 From Tag: Value of the tag parameter (if present) in the From header 522 field. 524 Call-Id: The value of the Call-ID header field. 526 Server-Txn: Server transaction identification code - the transaction 527 identifier associated with the server transaction. 528 Implementations can reuse the server transaction identifier (the 529 topmost branch-id of the incoming request, with or without the 530 magic cookie), or they could generate a unique identification 531 string for a server transaction (this identifier needs to be 532 locally unique to the server only.) This identifier is used to 533 correlate ACKs and CANCELs to an INVITE transaction; it is also 534 used to aid in forking. (See Section 9 of 535 [I-D.ietf-sipclf-problem-statement] for usage.) 537 Client-Txn: Client transaction identification code - this field is 538 used to associate client transactions with a server transaction 539 for forking proxies or B2BUAs. Upon forking, implementations can 540 reuse the value they inserted into the topmost Via header's branch 541 parameter, or they can generate a unique identification string for 542 the client transaction. (See Section 9 of 543 [I-D.ietf-sipclf-problem-statement] for usage.) 545 Note: The definitions of the Server-Txn and Client-Txn are taken 546 directly from [I-D.ietf-sipclf-problem-statement] and are provided 547 here only as a convenience to the implementer. The definitions 548 specified in [I-D.ietf-sipclf-problem-statement] should be 549 considered authoritative in the event of a conflict. 551 This data MUST appear in the order listed in , and 552 each field MUST be present. Fields are subject the maximum SIP CLF 553 field size of 4096 bytes as detailed in Section 8 of 554 [I-D.ietf-sipclf-problem-statement]. 556 4.3. SIP CLF Encoding and Character Escaping Requirements 558 The mandatory fields in a SIP CLF record are separated by a single 559 UTF-8 Tab character (0x09). Any Tab characters present in the data 560 to be written will be replaced by a UTF-8 space character (0x20) 561 prior to being logged. 563 The decision to replace tabs with spaces was based on there being no 564 standardized use of tabs in SIP headers to convey any other meaning 565 than whitespace. Tabs may appear in message bodies, and in the event 566 that the bodies are logged, the conversion to space may cause 567 problems when reconstructing the body from the corresponding log 568 entry. Two consequences of the decision to replace tab with a space 569 character are: (a) it will become impossible to reconstruct a 570 signature over the logged field that matches the signature over 571 fields in the original SIP message, and (b) any future SIP header 572 fields that include tabs with a different semantic meaning than 573 simply signifying whitespace will lose this meaning when logged. And 574 finally, the tabs to spaces substitution MUST occur when logging 575 mandatory fields and optional SIP Header Field or Reason-Phrase 576 (Tag=00); it MUST also occur when when optionally logging either the 577 entire message (Tag=02) or simply a SIP body (Tag=01) as described in 578 Section 4.4. 580 An element will not always have an appropriate value to provide for 581 one of these fields, even when the field is required to appear in the 582 SIP CLF record. In such circumstances, when a given mandatory field 583 from Section 4.2 and specified in Section 8.1 of 584 [I-D.ietf-sipclf-problem-statement]) is not present then that empty 585 field MUST be encoded as a single horizontal dash ("-"). In the 586 event that a field failed to parse it MUST be encoded as a single 587 question mark ("?"). If these characters are part of a sequence of 588 other characters, then there is no ambiguity. If the field being 589 logged contains only one character, and that character is the literal 590 "-", the implementation SHOULD insert an escaped %2D for that field 591 in the SIP CLF record. Similarly, if the field contains only one 592 character, and that character is the literal "?", the implementation 593 SHOULD insert an escaped %3F for that field in the SIP CLF record. 595 The terminating carriage return line feed (CRLF) after a given header 596 field value MUST NOT be logged. Since a bare CRLF sequence is not 597 permitted within a SIP header field value, mandatory fields MUST NOT 598 contain a CRLF when logged and consequently no escaping mechanism is 599 required for it. 601 Clearly a SIP parser could not possibly successfully parse a SIP CLF 602 record in its entirety given the SIP CLF format described in this 603 document. It is possible to parse individual fields in the SIP CLF 604 record if they are extracted and given to a SIP parser that would 605 normally parse those sequence of strings. It should be noted that 606 any field value that is modified by the escaping mechanisms defined 607 in this document before logging ('-','?', and CRLF) is likely no 608 longer well-formed SIP and will fail when given to such a parser. 610 The intent of logging using SIP CLF is not to faithfully recreate the 611 bit-exact SIP message being logged. In fact, the formatting rules, 612 encoding and character escaping requirements preclude this and may 613 introduce information loss relative to the original SIP message. A 614 log reader should never unescape anything in the SIP CLF record since 615 they are intended to be machine processed using text tools such as 616 grep and awk. The human user behind the log reader may be required 617 to infer more semantics about any differences between the original 618 SIP message and its SIP CLF representation. 620 4.4. Optional Fields 621 The portion of the SIP CLF record is shown below: 623 0 7 8 15 16 23 24 31 624 +-----------+-----------+-----------+-----------+ 625 | 0x09 | Tag | 0x40 |\ 626 +-----------+-----------+-----------+-----------+ \ 627 | Vendor-ID | \ 628 +-----------+-----------+-----------+-----------+ \ 629 | Vendor-ID (cont) | \ Repeated 630 +-----------+-----------+-----------+-----------+ \ as many 631 | 0x2C | Length (Hex) | > times as 632 +-----------+-----------+-----------+-----------+ / necessary 633 | Len (cont)| 0x2C | BEB | 0x2C | / 634 +-----------+-----------+-----------------------| / 635 | | / 636 | Value (variable length) | / 637 | |/ 638 +-----------+-----------+-----------+-----------+ 640 Figure 5: Optional Fields 642 Optional fields are those SIP message elements that are not a part of 643 the mandatory fields list detailed in Section 8.1 of 644 [I-D.ietf-sipclf-problem-statement]. After the 645 section, there is an OPTIONAL group (shown in 646 Figure 5) that MAY appear zero or more times. This 647 group provides extensibility to the SIP CLF. It allows SIP CLF 648 implementers the flexibility to extend the logging capability of this 649 indexed text representation beyond just the mandatory log elements 650 described in Section 8.1 of [I-D.ietf-sipclf-problem-statement]. 652 Logging any optional SIP elements MUST be done according to the 653 format shown in Figure 5. The location of the start of 654 within the SIP CLF record is indicated by the 655 "Optional Fields Start Pointer" field in . After the 656 initial Tab delimiter byte (0x09) shown in Figure 5, the optional 657 field being logged is generally represented by the notation: 659 Tag@Vendor-ID,Length,BEB,Value 661 The optional field identifier (Tag@Vendor-ID) is composed of a two 662 byte Tag and an eight byte Vendor-ID (both decimal encoded) separated 663 by an "@" character (0x40). This uniquely identifies the optional 664 field being logged. The format for this identifier is loosely 665 modeled after the private use option used by the Syslog protocol 666 [RFC5424] (Note: this is the second format detailed in Section 6.3.2 667 of [RFC5424]). It makes use of the Private Enterprise Number (PEN), 668 which provides an identifier through a globally unique name space 670 [PEN]. This syntax provides the necessary extensibility to SIP CLF 671 to allow logging of any SIP header, body, as well as any vendor- 672 specified SIP element. 674 The Base64 Encoded Byte (BEB) is a boolean that is used to indicate 675 whether the optional element being logged is Base64 encoded or not. 676 The Value field for the optional element being logged MUST be Base64 677 encoded if it has any characters that are 'unprintable'. For the 678 purposes of this document, we define 'unprintable' to mean a string 679 of octets that: (a) contains an octet with a value in the range of 0 680 to 31, inclusive; (b) contains an octet with a value of 127; or (c) 681 contains any series of octets greater than or equal to 128 which do 682 not form a valid UTF-8 sequence, as specified by [UNICODE]. If the 683 optional element being logged is Base64 encoded then BEB=0x01; if it 684 is not Base64 encoded then BEB=0x00. 686 Optional fields are logged according to the following two syntax 687 rules: 689 (1) Vendor-ID = 00000000 691 A Vendor-ID of zero is used to log the entire SIP message, message 692 body, Reason-Phrase or any SIP header fields that are not a part 693 of the mandatory fields list detailed in Section 8.1 of 694 [I-D.ietf-sipclf-problem-statement]. The following Tag values are 695 used to identify which of these optional elements are being 696 logged: 698 Tag = 00 - Log SIP Header Field or Reason-Phrase 700 When logging a SIP Header Field (Tag=00), the associated 701 "Value" field MUST be populated by the entire header field 702 being logged. That is, the field-name, the associated colon 703 (":") and the field-value. This mechanism provides the 704 capability to optionally log any SIP header field by 705 identifying the field being logged within the "Value" field. 707 Because the Reason-Phrase in a response is part of the Status- 708 Line and is not identified with a field-name, it is a special 709 case. In this instance, the the associated "Value" field MUST 710 be populated by the name "Reason-Phrase" followed by a colon 711 (":") and a single space (SP) between the colon and the logged 712 Reason-Phrase value. 714 The corresponding "Length" field includes the length of the 715 entire "Value" field. This includes the field-name, the colon, 716 and any LWS separator. For Tag=00 the BEB is set according to 717 whether the SIP Header Field value contains any 'unprintable' 718 characters. If it does not the BEB=00; if it does the BEB=01. 719 If BEB=01 then only the field-value MUST be Base64 encoded; the 720 field-name, the associated colon and any LWS separator MUST 721 retain their original encoding. 723 If an optional field occurs more than once in a SIP message 724 (e.g. Contact, Route, Record-Route, etc.) then each occurrence 725 MUST be logged with the same Tag value (i.e., Tag=00) as a 726 distinct optional field entry in the SIP CLF record. These 727 repeated optionally logged header fields MUST preserve the 728 ordinal position of the repeated header fields in the SIP 729 header. For example, a SIP header containing two Via header 730 fields with the following ordinal positions within the SIP 731 header: V1,V2. If optionally logging these header fields they 732 would occur as the following entries in the SIP CLF record. 733 (Note: For the sake of brevity this example only shows how 734 these optional header fields would be logged and omits the 735 remainder of the SIP CLF record): 737 00@00000000,len_V1,00,Via: V1 00@00000000,len_V2,00,Via: V2 739 The terminating carriage return line feed (CRLF) after a given 740 header field value MUST NOT be logged. Since a bare CRLF 741 sequence is not permitted within a SIP header field value, 742 optional SIP header fields logged with Tag=00 MUST NOT contain 743 a CRLF when logged and consequently no escaping mechanism is 744 required for it. 746 Tag = 01 - Log message body 748 SIP message bodies of all types can be optionally logged using 749 Tag=01. If the message body is logged it MUST adhere to the 750 maximum size limitation of 4096 bytes for a SIP CLF field, as 751 detailed in Section 8 of [I-D.ietf-sipclf-problem-statement]. 752 Unlike with Tag=00, there can only be a single entry in the SIP 753 CLF record with Tag=01. When optionally logging the message 754 body if the maximum SIP CLF field size of 4096 bytes is 755 exceeded the message body being logged MUST be truncated to 756 meet these size limitations. 758 When logging a message body (Tag=01), the associated "Value" 759 field is populated with the Content-Type itself plus the SIP 760 message body separated with a space. In this manner, 761 everything about the SIP message body is self-described using a 762 single tag as compared to enumerating a separate tag for each 763 body type. Additionally, the corresponding "Length" field 764 includes the SIP message body, the length of the embedded 765 Content-Type, and the space separator between the MIME type and 766 the body content. 768 For an optionally logged message body (Tag=01) the BEB is set 769 according to whether the message body contains any 770 'unprintable' characters. If it does not the BEB=00; if it 771 does the BEB=01. If BEB=01 then the message body that follows 772 is entirely Base64 encoded except the prepended Content-Type as 773 described in the previous paragraph. 775 If an optionally logged SIP message body contains any CRLFs 776 they MUST be escaped by using the URI encoded equivalent value 777 of "%0D%0A". This escaping mechanism applies to all body 778 types. So we don't make any distinction in treatment between 779 the various possible body types. If a logged message body has 780 BEB=01 then it MUST be Base64 encoded prior to any character 781 escaping. Thus, if a binary body (like an image) is logged it 782 will be Base64 encoded first and that Base64 character stream 783 could never include the CRLF escape sequence of "%0D%0A" 784 because "%" is not a valid Base64 character. 786 Tag = 02 - Log entire SIP message 788 The entire SIP message (i.e., SIP header and message body) can 789 be optionally logged using a Tag=02. Logging the entire SIP 790 message MUST conform to the maximum size limitation of 4096 791 bytes for a SIP CLF field, as detailed in Section 8 of 792 [I-D.ietf-sipclf-problem-statement]. Unlike with Tag=00, there 793 can only be a single entry in the SIP CLF record with Tag=02. 794 When optionally logging the entire SIP message if the maximum 795 SIP CLF field size of 4096 bytes is exceeded the entire SIP 796 message being logged MUST be truncated to meet these size 797 limitations. 799 When optionally logging an entire SIP message (Tag=02) the BEB 800 is set according to whether the message body portion contains 801 any 'unprintable' characters. If it does not the BEB=00; if it 802 does the BEB=01. If BEB=01 then the entire SIP message is 803 Base64 encoded (not just the message body). Note that unlike 804 the case of Tag=01, when logging an entire SIP message (Tag=02) 805 with 'unprintable' characters (BEB=01) the Content-Type would 806 not be known prior to decode. 808 All instances of CRLFs, whether they appear in the SIP headers 809 or the SIP message body MUST be escaped by using the URI 810 encoded equivalent value of "%0D%0A". If a logged SIP message 811 has BEB=01 then it MUST be Base64 encoded prior to any 812 character escaping. 814 (2) Vendor-ID = PEN 816 A Vendor-ID set to a vendor's own private enterprise number from 817 the complete current list of private enterprise numbers maintained 818 by IANA [PEN] is used to log any other vendor-specified optional 819 element of a SIP header or body. The value of the Tag is set at 820 the discretion of the implementer: 822 Tag = Vendor-specified tag 824 The definition of the various values of the optional field identifier 825 (Tag@Vendor-ID) are the basis of how optional elements are logged in 826 the SIP CLF. For the sake of completeness the remaining fields in 827 the format shown in Figure 5 are also defined below: 829 Length Field (4 bytes): Indicates the length of only the "Value" 830 field of this optionally logged element (as shown in Figure 5), 831 hexadecimal encoded. This length corresponds to the length of the 832 "Value" field only and MUST NOT include any of the other elements 833 shown in Figure 5. 835 Base64 Encoded Byte (BEB) Field (1 byte): Indicates whether the 836 subsequent Value Field of the optionally logged element is Base64 837 encoded or not. The Value field for the optional element being 838 logged MUST be Base64 encoded if it contains any character that is 839 deemed 'unprintable' according to the definition given previously 840 in this section. If the optional element being logged is Base64 841 encoded then BEB=0x01; if it is not Base64 encoded then BEB=0x00. 843 Value Field (0 to 4096 bytes): Contains the actual value of this 844 optional field. As with the mandatory fields, UTF-8 Tab 845 characters (0x09) are replaced with UTF-8 space characters (0x20). 847 The following are examples of optionally logged SIP elements using 848 the syntax described in this section. All these examples only show 849 the portion of the SIP CLF record. The mandatory 850 and portions of the SIP CLF are 851 intentionally omitted for the sake of brevity. Note that all of 852 these examples of optionally logged fields begin with a leading Tab 853 delimiter byte (0x09) that is not apparent here. 855 (1) Contact header field logged as an optional field: 857 Consider the SIP response: 859 SIP/2.0 180 Ringing 860 861 Via: SIP/2.0/UDP host.example.com; 862 branch=z9hG4bKnashds8;received=192.0.2.1 863 864 To: Bob ;tag=a6c85cf 865 From: Alice ;tag=1928301774 866 Call-ID: a84b4c76e66710 867 Contact: 868 CSeq: 314159 INVITE 869 Content-Length: 0 871 The Contact header field would be logged as an optional field in 872 the following manner: 874 00@00000000,001C,00,Contact: 876 (2) Reason-Phrase logged as an optional field: 878 For the same SIP response the Reason-Phrase would be logged as 879 an optional field in the following manner: 881 00@00000000,0016,00,Reason-Phrase: Ringing 883 (3) SDP body to be logged as an optional field: 885 v=0 886 o=alice 2890844526 2890844526 IN IP4 host.example.com 887 s=- 888 c=IN IP4 host.example.com 889 t=0 0 890 m=audio 49170 RTP/AVP 0 8 97 892 This body has a Content-Type of application/sdp and is of length 893 of 123 bytes including all the line-feeds. When logging this 894 body the "Value" field is composed of the Content-Type and the 895 body separated by a space, which gives it a combined length of 896 139 (0x008B) bytes. This SIP body would be logged as an 897 optional field in the following manner: 899 900 01@00000000,008B,00,application/sdp v=0%0D%0Ao=alice 2890844526 901 2890844526 IN IP4 host.example.com%0D%0As=-%0D%0A 902 c=IN IP4 host.example.com%0D%0At=0 0%0D%0A 903 m=audio 49170 RTP/AVP 0 8 97%0D%0A 904 906 Note that the body is actually logged on a single line and is 907 thus captured between tags. The line-feeds are 908 escaped using %0D%0A to delimit the various lines in the message 909 body. 911 (4) binary body to be logged as an optional field: 913 The second body part of the multipart/mime SIP message shown in 914 Section 3.1.1.11 of RFC4475 is a binary encoded body 915 (represented in hex) and if logged would have BEB=01 and would 916 require Base64 encoding. That binary body would produce six 917 lines of output after being Base64 encoded. Subsequent escaping 918 of the CRLF characters would produce an optionally logged body 919 that would look like: 921 922 01@00000000,0216,01,multipart/mixed;boundary=7a9cbec02ceef655 MI 923 IBUgYJKoZIhvcNAQcCoIIBQzCCAT8CAQExCTAHBgUrDgMCGjALBgkqhkiG9w0BBw 924 ExggEgMIIB%0D%0AHAIBATB8MHAxCzAJBgNVBAYTAlVTMRMwEQYDVQQIEwpDYWxp 925 Zm9ybmlhMREwDwYDVQQHEwhTYW4g%0D%0ASm9zZTEOMAwGA1UEChMFc2lwaXQxKT 926 AnBgNVBAsTIFNpcGl0IFRlc3QgQ2VydGlmaWNhdGUgQXV0%0D%0AaG9yaXR5AggB 927 lQBxAjMBEzAHBgUrDgMCGjANBgkqhkiG9w0BAQEFAASBgI70ZvlI8FIt0uWXjp2V 928 %0D%0Aquny/hWgZllxYpLo2iqo2DUKaM7/rjy9K/8Wdd3VZI5ZPdZHKPJiIPfpQX 929 SeMw2aFe2r25PRDEIQ%0D%0ALntyidKcwMmuLvvHwM/5Fy87An5PwCfhVG3ktqo6 930 uz5mzMtd1sZLg4MUnLjm/xgtlE/le2W8mdAF%0D%0A 931 933 Note that the body is actually logged on a single line and is 934 thus captured between tags. The line-feeds are 935 escaped using %0D%0A to delimit the various lines in the Base64 936 encoded binary body. 938 (5) Codec information from the SDP body logged as an optional field: 940 Consider the SIP message: 942 INVITE sip:bob@example.com SIP/2.0 943 Via: SIP/2.0/UDP host.example.com;branch=z9hG4bKnashds8 944 To: Bob 945 From: Alice ;tag=1928301774 946 Call-ID: a84b4c76e66710 947 CSeq: 314159 INVITE 948 Max-Forwards: 70 949 Date: Thu, 21 Feb 2002 13:02:03 GMT 950 Contact: 951 Content-Type: application/sdp 952 Content-Length: 147 954 v=0 955 o=UserA 2890844526 2890844526 IN IP4 example.com 956 s=Session SDP 957 c=IN IP4 host.example.com 958 t=0 0 959 m=audio 49172 RTP/AVP 0 960 a=rtpmap:0 PCMU/8000 962 A vendor may choose to log a SIP message element such as the 963 codec information from the SDP body. This Vendor-specified SIP 964 element would be logged as an optional field in the following 965 manner: 967 03@00032473,0014,00,a=rtpmap:0 PCMU/8000 969 (6) N-th message received from a particular peer logged as an 970 optional field: 972 Perhaps a vendor wants to log that this message is the n-th 973 message received from a peering partner. To do so for the SIP 974 message shown above, the vendor would log this information as: 976 07@00032473,0016,00,1877 example.com 978 Which would signify that this is the 1,877th message from the 979 peering partner example.com. Note that the previous two 980 examples showing an optionally logged Vendor-specified SIP 981 element use a Vendor-ID with a Private Enterprise Number of 982 32473. This value has been reserved by IANA to be used as an 983 example PEN in documentation according to [RFC5612]. 985 5. Example SIP CLF Record 987 The following SIP message is an INVITE request sent by a SIP client: 989 INVITE sip:192.0.2.10 SIP/2.0 990 To: 991 Call-ID: DL70dff590c1-1079051554@example.com 992 993 From: "Alice" ; 994 tag=DL88360fa5fc;epid=0x34619b0 995 996 CSeq: 1 INVITE 997 Max-Forwards: 70 998 Date: Thu, 21 Feb 2012 15:02:03 GMT 999 1000 Via: SIP/2.0/TCP 192.0.2.200:5060; 1001 branch=z9hG4bK-1f6be070c4-DL 1002 1003 Contact: "1001" 1004 Content-Type: application/sdp 1005 Content-Length: 418 1007 v=0 1008 o=1001 1456139204 0 IN IP4 192.0.2.200 1009 s=Session SDP 1010 c=IN IP4 192.0.2.200 1011 b=AS:2048 1012 t=0 0 1013 m=audio 13756 RTP/AVP 0 101 1014 a=rtpmap:0 PCMU/8000 1016 Shown below is approximately how this message would appear as a 1017 single record in a SIP CLF logging file if encoded according to the 1018 syntax described in this document. Due to RFC conventions, this log 1019 entry has been split into five lines, instead of the two lines that 1020 actually appear in a log file; and the tab characters have been 1021 padded out using spaces to simulate their appearance in a text 1022 terminal. 1024 A000100,0053005C005E006D007D008F009E00A000BA00C700EB00F70100 1025 1026 1328821153.010 RORUU 1 INVITE - sip:192.0.2.10 1027 192.0.2.10:5060 192.0.2.200:56485 sip:192.0.2.10 - 1028 sip:1001@example.com:5060 DL88360fa5fc 1029 DL70dff590c1-1079051554@example.com S1781761-88 C67651-11 1030 1032 A bit-exact version of the actual log entry is provided here, Base64 1033 encoded. 1035 begin-base64 644 clf_record 1036 QTAwMDEwMCwwMDUzMDA1QzAwNUUwMDZEMDA3RDAwOEYwMDlFMDBBMDAwQkEwMEM3MDBF 1037 QjAwRjcwMTAwCjEzMjg4MjExNTMuMDEwCVJPUlVVCTEgSU5WSVRFCS0Jc2lwOjE5Mi4w 1038 LjIuMTAJMTkyLjAuMi4xMDo1MDYwCTE5Mi4wLjIuMjAwOjU2NDg1CXNpcDoxOTIuMC4y 1039 LjEwCS0Jc2lwOjEwMDFAZXhhbXBsZS5jb206NTA2MAlETDg4MzYwZmE1ZmMJREw3MGRm 1040 ZjU5MGMxLTEwNzkwNTE1NTRAZXhhbXBsZS5jb20JUzE3ODE3NjEtODgJQzY3NjUxLTEx 1041 Cg== 1042 ==== 1044 To recover the unencoded file, the Base64 text above may be passed as 1045 input to the following perl script (the output should be redirected 1046 to a file). 1048 1050 #!/usr/bin/perl 1051 use strict; 1052 my $bdata = ""; 1053 use MIME::Base64; 1054 while(<>) 1055 { 1056 if (/begin-base64 644 clf_record/ .. /-- ==== --/) 1057 { 1058 if ( m/^\s*[^\s]+\s*$/) 1059 { 1060 $bdata = $bdata . $_; 1061 } 1062 } 1063 } 1064 print decode_base64($bdata); 1066 1068 6. Text Tool Considerations 1070 This format has been designed to allow text tools to easily process 1071 logs without needing to understand the indexing format. Index lines 1072 may be rapidly discarded by checking the first character of the line: 1073 index lines will always start with an alphabetical character, while 1074 field lines will start with a numerical character. 1076 Within a field line, script tools can quickly split fields at the tab 1077 characters. The first 12 fields are positional, and the meaning of 1078 any subsequent fields can be determined by checking the first four 1079 characters of the field. Alternately, these non-positional fields 1080 can be located using a regular expression. For example, the "Contact 1081 value" in a request can be found by searching for the perl regex 1082 /\t0000,....,([^\t]*)/. 1084 7. Security Considerations 1086 This document does not introduce any new security considerations 1087 beyond those discussed in [I-D.ietf-sipclf-problem-statement]. 1089 In the interest of protecting the sensitive information contained in 1090 a SIP CLF file, [I-D.ietf-sipclf-problem-statement] notes that values 1091 might need to be obfuscated for privacy reasons when SIP CLF files 1092 are exchanged between domains. If a base64 encoded string contains 1093 the non-obfuscated value then that would also need to be obfuscated 1094 before base64 encoding. 1096 8. Operational Guidance 1098 SIP CLF log files will take up substantive amount of disk space 1099 depending on traffic volume at a processing entity and the amount of 1100 information being logged. As such, any enterprise using SIP CLF 1101 should establish operational procedures for file rollovers as 1102 appropriate to the needs of the organization. 1104 Listing such operational guidelines in this document is out of scope 1105 for this work. 1107 9. IANA Considerations 1109 This specification establishes a new Session Initiation Protocol 1110 (SIP) Common Log Format (CLF) Parameters registry, which contains two 1111 new sub-registries for SIP CLF Version and SIP CLF Transport Flag. 1112 Initial entries are defined by this specification for both sub- 1113 registries. Addition of any new sub-registry to the Session 1114 Initiation Protocol (SIP) Common Log Format (CLF) Parameters registry 1115 is to be done using the IETF Review registration policy detailed in 1116 [RFC5226]. 1118 9.1. SIP CLF Version 1120 This document defines the SIP CLF "Version" field in Section 4.1. 1121 IANA has created a registry of Version values entitled "SIP CLF 1122 Version Values". Version numbers MUST be incremented for any new SIP 1123 CLF protocol specification that changes any part of the SIP CLF 1124 record format. Changes include addition or removal of fields or a 1125 change of syntax or semantics of existing fields. 1127 Version numbers must be registered via the Standards Action method as 1128 described in [RFC5226]. IANA has registered the Versions shown in 1129 Table 1 below. 1131 +---------+--------------------+-----------+ 1132 | Version | FORMAT | Reference | 1133 +---------+--------------------+-----------+ 1134 | 0x41 | Defined in RFCXXXX | RFCXXXX | 1135 +---------+--------------------+-----------+ 1137 Table 1: IANA-Registered SIP CLF Versions 1139 [[NOTE TO RFC EDITOR: Please change XXXX to the number assigned to 1140 this specification, and remove this paragraph on publication.]] 1142 9.2. SIP CLF Transport Flag 1144 This document defines the SIP CLF "Transport Flag" as fourth byte in 1145 the Flags Field of the SIP CLF record. The format and values of the 1146 Transport Flag are described in Section 4.2. IANA has created a 1147 registry of SIP CLF Transport Flag values entitled "SIP CLF Transport 1148 Flag Values". 1150 SIP CLF Transport Flag values must be registered via the IETF Review 1151 method as described in [RFC5226]. IANA has registered the Transport 1152 Flag values shown in Table 2 below. 1154 +-------+--------------------+-----------+ 1155 | Value | Transport Protocol | Reference | 1156 +-------+--------------------+-----------+ 1157 | U | UDP | RFCXXXX | 1158 | T | TCP | RFCXXXX | 1159 | S | SCTP | RFCXXXX | 1160 +-------+--------------------+-----------+ 1162 Table 2: IANA-Registered SIP CLF Transport Flag 1164 [[NOTE TO RFC EDITOR: Please change XXXX to the number assigned to 1165 this specification, and remove this paragraph on publication.]] 1167 10. Acknowledgements 1169 The authors of this document would like to acknowledge and thank 1170 Peter Musgrave (the chair of the SIPCLF working group) and Robert 1171 Sparks (the assigned area director) for their support, guidance, and 1172 continued invaluable feedback. 1174 This work benefited from the discussions and invaluable input by the 1175 various members of the SIPCLF working group. These include Brian 1176 Trammell, Eric Burger, Cullen Jennings, Benoit Claise, Saverio 1177 Niccolini, Dan Burnett. Special thanks to Hadriel Kaplan, Chris 1178 Lonvick, Paul E. Jones, John Elwell, Claudio Allocchio, and Joe 1179 Clarke for their constructive comments, suggestions, and reviews that 1180 were critical to the formulation and refinement of this document. 1182 Thanks to Anders Nygren for his early implementation, insight, and 1183 reviews of the SIP CLF format. 1185 This document was written with the xml2rfc tool described in 1186 [RFC2629]. 1188 11. References 1190 11.1. Normative References 1192 [I-D.ietf-sipclf-problem-statement] 1193 Gurbani, V., Burger, E., Anjali, T., Abdelnur, H., and O. 1194 Festor, "The Common Log Format (CLF) for the Session 1195 Initiation Protocol (SIP): Framework and Data Model", 1196 draft-ietf-sipclf-problem-statement-11 (work in progress), 1197 March 2012. 1199 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 1200 Requirement Levels", BCP 14, RFC 2119, March 1997. 1202 [RFC3261] Rosenberg, J., Schulzrinne, H., Camarillo, G., Johnston, 1203 A., Peterson, J., Sparks, R., Handley, M., and E. 1204 Schooler, "SIP: Session Initiation Protocol", RFC 3261, 1205 June 2002. 1207 11.2. Informative References 1209 [PEN] IANA, "Private Enterprise Numbers", 1210 http://www.iana.org/assignments/enterprise-numbers , 2009. 1212 [RFC1166] Kirkpatrick, S., Stahl, M., and M. Recker, "Internet 1213 numbers", RFC 1166, July 1990. 1215 [RFC2629] Rose, M., "Writing I-Ds and RFCs using XML", RFC 2629, 1216 June 1999. 1218 [RFC4475] Sparks, R., Hawrylyshen, A., Johnston, A., Rosenberg, J., 1219 and H. Schulzrinne, "Session Initiation Protocol (SIP) 1220 Torture Test Messages", RFC 4475, May 2006. 1222 [RFC5226] Narten, T. and H. Alvestrand, "Guidelines for Writing an 1223 IANA Considerations Section in RFCs", BCP 26, RFC 5226, 1224 May 2008. 1226 [RFC5424] Gerhards, R., "The Syslog Protocol", RFC 5424, March 2009. 1228 [RFC5612] Eronen, P. and D. Harrington, "Enterprise Number for 1229 Documentation Use", RFC 5612, August 2009. 1231 [RFC5737] Arkko, J., Cotton, M., and L. Vegoda, "IPv4 Address Blocks 1232 Reserved for Documentation", RFC 5737, January 2010. 1234 [RFC5952] Kawamura, S. and M. Kawashima, "A Recommendation for IPv6 1235 Address Text Representation", RFC 5952, August 2010. 1237 [UNICODE] "The Unicode Consortium, The Unicode Standard, Version 1238 6.2.0, (Mountain View, CA: ISBN 978-1-936213-07-8)", 1239 http://www.unicode.org/versions/Unicode6.2.0/ , 2012. 1241 [W3C.REC-xml-20081126] 1242 Sperberg-McQueen, C., Yergeau, F., Maler, E., Paoli, J., 1243 and T. Bray, "Extensible Markup Language (XML) 1.0 (Fifth 1244 Edition)", World Wide Web Consortium Recommendation REC- 1245 xml-20081126, November 2008, 1246 . 1248 Authors' Addresses 1250 Gonzalo Salgueiro 1251 Cisco Systems 1252 7200-12 Kit Creek Road 1253 Research Triangle Park, NC 27709 1254 US 1256 Email: gsalguei@cisco.com 1258 Vijay Gurbani 1259 Bell Labs, Alcatel-Lucent 1260 1960 Lucent Lane 1261 Rm 9C-533 1262 Naperville, IL 60563 1263 US 1265 Email: vkg@bell-labs.com 1267 Adam Roach 1268 Tekelec 1269 17210 Campbell Rd. 1270 Suite 250 1271 Dallas, TX 75252 1272 US 1274 Email: adam@nostrum.com