Request for Comments: 3485 Ericsson
Category: Standards Track C. Bormann
J. Ott
TZI/Uni Bremen
R. Price
Siemens/Roke Manor
A. B. Roach
dynamicsoft
February 2003
The Session Initiation Protocol (SIP) and Session Description Protocol
(SDP) Static Dictionary for Signaling Compression (SigComp)
Status of this Memo
This document specifies an Internet standards track protocol for the
Internet community, and requests discussion and suggestions for
improvements. Please refer to the current edition of the "Internet
Official Protocol Standards" (STD 1) for the standardization state
and status of this protocol. Distribution of this memo is unlimited.
Copyright Notice
Copyright (C) The Internet Society (2003). All Rights Reserved.
Abstract
The Session Initiation Protocol (SIP) is a text-based protocol for
initiating and managing communication sessions. The protocol can be
compressed by using Signaling Compression (SigComp). Similarly, the
Session Description Protocol (SDP) is a text-based protocol intended
for describing multimedia sessions for the purposes of session
announcement, session invitation, and other forms of multimedia
session initiation. This memo defines the SIP/SDP-specific static
dictionary that SigComp may use in order to achieve higher
efficiency. The dictionary is compression algorithm independent.
Table of Contents
1. Introduction.....................................................2
2. Design considerations............................................3
3. Binary representation of the SIP/SDP dictionary..................5
4. Security Considerations.........................................13
5. IANA Considerations.............................................13
6. Acknowledgements................................................14
7. References......................................................14
7.1 Normative References........................................14
7.2 Informative References......................................14
Appendix A. SIP input strings to the SIP/SDP static dictionary.....17
Appendix B. SDP input strings to the SIP/SDP static dictionary.....26
Authors' Addresses.................................................29
Full Copyright Statement...........................................30
1. Introduction
SIP [3] and SDP [24] are text-based protocols that use the UTF-8
charset (RFC2279 [5]). SIP and SDP were designed for rich bandwidth
links. However, when SIP/SDP is run over narrow bandwidth links,
such as radio interfaces or low speed serial links, the session setup
time increases substantially, compared to an operation over a rich
bandwidth link.
The session setup time can decrease dramatically if the SIP/SDP
signaling is compressed. The signaling compression mechanisms
specified in SigComp [1] provide a multiple compression/decompression
algorithm framework to compress and decompress text-based protocols
such as SIP and SDP.
When compression is used in SIP/SDP, the compression achieves its
maximum rate once a few message exchanges have taken place. This is
due to the fact that the first message the compressor sends to the
decompressor is only partially compressed, as there is not a previous
stored state to compress against. As the goal is to reduce the
session setup time as much as possible, it seems sensible to
investigate a mechanism to boost the compression rate from the first
message.
In this memo we introduce the static dictionary for SIP and SDP. The
dictionary is to be used in conjunction with SIP, SDP and SigComp.
The static SIP/SDP dictionary constitutes a SigComp state that can be
referenced in the first SIP message that the compressor sends out.
2. Design considerations
The static SIP/SDP dictionary is a collection of well-known strings
that appear in most of the SIP and SDP messages. The dictionary is
not a comprehensive list of reserved words, but it includes many of
the strings that appear in SIP and SDP signaling.
The static dictionary is unique and MUST be available in all SigComp
implementations for SIP/SDP. The dictionary is not intended to
evolve as SIP or SDP evolve. It is defined once, and stays as is
forever. This solves the problems of updating, upgrading and finding
out the dictionary that is supported at the remote end when several
versions of the same dictionary coexist.
Appendix A contains the collection of strings that SIP contributed to
the static dictionary. The appendix includes references to the
documents that define those strings.
Appendix B contains the collection of strings that SDP contributed to
the static dictionary. Again, the appendix includes references to
the documents that define those strings.
While these appendices are of an informative nature, Section 3 gives
the normative binary form of the SIP/SDP dictionary. This is the
dictionary that is included in the SigComp implementation. This
dictionary has been formed from the collection of individual
dictionaries given in appendices A and B.
The two input collections are collections of UTF-8 encoded character
strings. In order to facilitate the readability, the appendices
describe them in one table for each collection. In these tables,
each row represents an entry. Each entry contains the string that
actually occurs in the dictionary, its priority (see below), its
offset from the first octet and its length (both in hexadecimal), and
one or more references that elucidate why this string is expected to
occur in SIP/SDP messages. Note: Length in this document always
refers to octets.
The columns in the tables are described as follows:
String: represents the UTF-8 string that is inserted into the
dictionary. Note that the quotes (") are not part of the string
itself. Note also that the notation [CRLF] represents a Carriage
Return character (ASCII code 0x0D) followed by a Line Feed character
(ASCII code 0x0A).
Pr: indicates the priority of this string within the dictionary.
Some compression algorithms, such as DEFLATE, offer an increased
efficiency when the most commonly used strings are located at the
bottom of the dictionary. To facilitate generating a dictionary that
has the most frequently occurring strings further down at the bottom,
we have decided to allocate a priority to each string in the
dictionary. Priorities range from 1 until 5. A low number in the
priority column (e.g., 1) indicates that we believe in a high
probability of finding the string in SIP or SDP messages. A high
number in the priority column (e.g., 5) indicates lower probability
of finding the string in a SIP or SDP message. This is typically the
case for less frequent error codes or optional infrequent tags.
Off: indicates the hexadecimal offset of the entry with respect to
the first octet in the dictionary. Note that several strings in the
collections can share space in the dictionary if they exhibit
suitable common substrings.
Len: the length of the string (in octets, in hexadecimal).
References: contains one or more references to the specification and
the section within the specification where the string is defined.
Note that the strings stored in the dictionary are case sensitive.
(Again, the strings do not comprise the quotes ("), they are just
shown here to increase the readability.) Where the string is a
header field, we also included the colon ":" and the amount of white
space expected to occur. Note that this means that not all messages
that conform to the SIP Augmented BNF, which allows other
combinations (e.g., a white space or horizontal tabulator before the
colon (":") sign), will benefit as much from the dictionary -- the
best increase in compression performance is to be expected for
messages that use the recommended formatting guidelines for SIP.
Some strings appear followed by an equal sign and some others do not.
This depends on whether the string is part of a parameter name or a
parameter value.
In a SIP message, all the SIP headers terminate with a CRLF pair of
characters. As these characters are appended to the end of each SIP
header line, right after the header values, and because the header
values are typically not part of the static SIP dictionary, we cannot
include the terminating CRLF as part of the SIP static dictionary.
Instead, the approach we have taken is to include in each header
field entry the CRLF from the previous line that prefixes every
header field. We have represented CRLF by the notation [CRLF].
Therefore, in generating the actual binary dictionary, an entry in
the dictionary represented as: "[CRLF]From: " has been interpreted as
an entry whose value is CR, LF, the word From, a colon and a
whitespace.
Note that most SIP header field names are included with the full
string from CRLF to the colon-blank pair. However, in certain
situations, when the likelihood of occurrence is not considered high
(as indicated by a priority value of 3 to 5), and when there are
common substrings shared by a number of headers, we have added one
entry with the common substring and several entries with the non-
common substrings remaining. An example is the "Proxy-Authenticate"
and "Proxy-Authorization" headers. There are three entries in the
dictionary: the common substring "[CRLF]Proxy-", and the non-common
substrings "Authenticate: " and "Authorization: ". This allows the
re-use of the non-common substrings by other entries and may save a
number of bytes in the binary form of the dictionary. Note that this
splitting mechanism does not apply with strings that are likely to
occur very often (those whose priority is set to 1 or 2).
SIP responses start with a status code (e.g., "302") and a reason
phrase (e.g., "Moved Temporarily"). The status code is a normative
part, whereas the reason phrase is not normative, it is just a
suggested text. For instance, both "302 Moved Temporarily" and "302
Redirect" are valid beginnings of SIP responses.
In the SIP dictionary we have included two entries per response code,
one including only the status code and a space (e.g., "302 ") and
another one including both the status code and the suggested reason
phrase (e.g., "302 Moved Temporarily"). The former can be used when
the SIP response changed the suggested reason phrase to another one.
The latter can be used when the suggested reason phrase is part of
the response. In this way, we accommodate both alternatives. (Note
that in the actual dictionary, both strings occupy the same space in
the string subset, but have two separate entries in the table
subset.)
3. Binary representation of the SIP/SDP dictionary
This section contains the result of combining the SIP and the SDP
dictionaries described in appendices A and B in order to create a
single dictionary that is loaded into SigComp as a state.
The binary SigComp dictionary is comprised of two parts, the
concatenation of which serves as the state value of the state item: A
string subset, which contains all strings in the contributing
collections as a substring (roughly ordered such that strings with
low priority numbers occur at the end), and a table subset, which
contains pairs of length and offset values for all the strings in the
contributing collections. In each of these pairs, the length is
stored as a one-byte value, and the offset is stored as a two-byte
value that has had 1024 added to the offset (this allows direct
referencing from the stored value if the dictionary state has been
loaded at address 1024).
The intention is that all compression algorithms will be able to use
the (or part of the) string subset, and some compression methods,
notably those that are related to the LZ78 family, will also use the
table in order to form an initial set of tokens for that compression
method. The text below therefore gives examples for referencing both
the table subset and the string subset of the dictionary state item.
As defined in section 3.3.3 in the Signaling Compression
specification [1], a SigComp state is characterized by a certain set
of information. For the static SIP/SDP dictionary, the information
in the following Table 1 fully characterizes the state item.
Note that the string subset of the dictionary can be accessed using:
STATE-ACCESS (%ps, 6, 0, 0x0D8C, %sa, 0),
and the table subset can be accessed using:
STATE-ACCESS (%ps, 6, 0x0D8C, 0x0558, %sa, 0),
where %ps points to UDVM memory containing
0xfbe507dfe5e6
and %sa is the desired destination address in UDVM memory (with UDVM
byte copying rules applied).
If only a subset of the dictionary up to a specific priority is
desired (e.g., to save UDVM space), the values for the third and
forth operand in these STATE-ACCESS instructions can be changed to:
Priorities String String Table Table
desired offset length offset length
========== ====== ====== ====== ======
1 only 0x0CB2 0x00DA 0x0D8C 0x003F
1..2 0x0920 0x046C 0x0D8C 0x0147
1..3 0x07B8 0x05D4 0x0D8C 0x01A7
1..4 0x0085 0x0D07 0x0D8C 0x044A
1..5 0x0000 0x0D8C 0x0D8C 0x0558
The state item consists of the following elements:
Name: Value:
===================== ========================
state_identifier 0xfbe507dfe5e6aa5af2abb914ceaa05f99ce61ba5
state_length 0x12E4
state_address 0 (not relevant for the dictionary)
state_instruction 0 (not relevant for the dictionary)
minimum_access_length 6
state_value Representation of the table below.
0000 0d0a 5265 6a65 6374 2d43 6f6e 7461 6374 ..Reject-Contact
0010 3a20 0d0a 4572 726f 722d 496e 666f 3a20 : ..Error-Info:
0020 0d0a 5469 6d65 7374 616d 703a 200d 0a43 ..Timestamp: ..C
0030 616c 6c2d 496e 666f 3a20 0d0a 5265 706c all-Info: ..Repl
0040 792d 546f 3a20 0d0a 5761 726e 696e 673a y-To: ..Warning:
0050 200d 0a53 7562 6a65 6374 3a20 3b68 616e ..Subject: ;han
0060 646c 696e 673d 696d 6167 653b 7075 7270 dling=image;purp
0070 6f73 653d 3b63 6175 7365 3d3b 7465 7874 ose=;cause=;text
0080 3d63 6172 6433 3030 204d 756c 7469 706c =card300 Multipl
0090 6520 4368 6f69 6365 736d 696d 6573 7361 e Choicesmimessa
00A0 6765 2f73 6970 6672 6167 3430 3720 5072 ge/sipfrag407 Pr
00B0 6f78 7920 4175 7468 656e 7469 6361 7469 oxy Authenticati
00C0 6f6e 2052 6571 7569 7265 6469 6765 7374 on Requiredigest
00D0 2d69 6e74 6567 7269 7479 3438 3420 4164 -integrity484 Ad
00E0 6472 6573 7320 496e 636f 6d70 6c65 7465 dress Incomplete
00F0 6c65 7068 6f6e 652d 6576 656e 7473 3439 lephone-events49
0100 3420 5365 6375 7269 7479 2041 6772 6565 4 Security Agree
0110 6d65 6e74 2052 6571 7569 7265 6465 6163 ment Requiredeac
0120 7469 7661 7465 6434 3831 2043 616c 6c2f tivated481 Call/
0130 5472 616e 7361 6374 696f 6e20 446f 6573 Transaction Does
0140 204e 6f74 2045 7869 7374 616c 653d 3530 Not Existale=50
0150 3020 5365 7276 6572 2049 6e74 6572 6e61 0 Server Interna
0160 6c20 4572 726f 726f 6275 7374 2d73 6f72 l Errorobust-sor
0170 7469 6e67 3d34 3136 2055 6e73 7570 706f ting=416 Unsuppo
0180 7274 6564 2055 5249 2053 6368 656d 6572 rted URI Schemer
0190 6765 6e63 7934 3135 2055 6e73 7570 706f gency415 Unsuppo
01A0 7274 6564 204d 6564 6961 2054 7970 656e rted Media Typen
01B0 6469 6e67 3438 3820 4e6f 7420 4163 6365 ding488 Not Acce
01C0 7074 6162 6c65 2048 6572 656a 6563 7465 ptable Herejecte
01D0 6434 3233 2049 6e74 6572 7661 6c20 546f d423 Interval To
01E0 6f20 4272 6965 6672 6f6d 2d74 6167 512e o Briefrom-tagQ.
01F0 3835 3035 2056 6572 7369 6f6e 204e 6f74 8505 Version Not
0200 2053 7570 706f 7274 6564 3430 3320 466f Supported403 Fo
0210 7262 6964 6465 6e6f 6e2d 7572 6765 6e74 rbiddenon-urgent
0220 3432 3920 5072 6f76 6964 6520 5265 6665 429 Provide Refe
0230 7272 6f72 2049 6465 6e74 6974 7934 3230 rror Identity420
0240 2042 6164 2045 7874 656e 7369 6f6e 6f72 Bad Extensionor
0250 6573 6f75 7263 650d 0a61 3d6b 6579 2d6d esource..a=key-m
0260 676d 743a 6d69 6b65 794f 5054 494f 4e53 gmt:mikeyOPTIONS
0270 204c 616e 6775 6167 653a 2035 3034 2053 Language: 504 S
0280 6572 7665 7220 5469 6d65 2d6f 7574 6f2d erver Time-outo-
0290 7461 670d 0a41 7574 6865 6e74 6963 6174 tag..Authenticat
02A0 696f 6e2d 496e 666f 3a20 4465 6320 3338 ion-Info: Dec 38
02B0 3020 416c 7465 726e 6174 6976 6520 5365 0 Alternative Se
02C0 7276 6963 6535 3033 2053 6572 7669 6365 rvice503 Service
02D0 2055 6e61 7661 696c 6162 6c65 3432 3120 Unavailable421
02E0 4578 7465 6e73 696f 6e20 5265 7175 6972 Extension Requir
02F0 6564 3430 3520 4d65 7468 6f64 204e 6f74 ed405 Method Not
0300 2041 6c6c 6f77 6564 3438 3720 5265 7175 Allowed487 Requ
0310 6573 7420 5465 726d 696e 6174 6564 6175 est Terminatedau
0320 7468 2d69 6e74 6572 6c65 6176 696e 673d th-interleaving=
0330 0d0a 6d3d 6170 706c 6963 6174 696f 6e20 ..m=application
0340 4175 6720 3531 3320 4d65 7373 6167 6520 Aug 513 Message
0350 546f 6f20 4c61 7267 6536 3837 2044 6961 Too Large687 Dia
0360 6c6f 6720 5465 726d 696e 6174 6564 3330 log Terminated30
0370 3220 4d6f 7665 6420 5465 6d70 6f72 6172 2 Moved Temporar
0380 696c 7933 3031 204d 6f76 6564 2050 6572 ily301 Moved Per
0390 6d61 6e65 6e74 6c79 6d75 6c74 6970 6172 manentlymultipar
03A0 742f 7369 676e 6564 0d0a 5265 7472 792d t/signed..Retry-
03B0 4166 7465 723a 2047 4d54 6875 2c20 3430 After: GMThu, 40
03C0 3220 5061 796d 656e 7420 5265 7175 6972 2 Payment Requir
03D0 6564 0d0a 613d 6f72 6965 6e74 3a6c 616e ed..a=orient:lan
03E0 6473 6361 7065 3430 3020 4261 6420 5265 dscape400 Bad Re
03F0 7175 6573 7472 7565 3439 3120 5265 7175 questrue491 Requ
0400 6573 7420 5065 6e64 696e 6735 3031 204e est Pending501 N
0410 6f74 2049 6d70 6c65 6d65 6e74 6564 3430 ot Implemented40
0420 3620 4e6f 7420 4163 6365 7074 6162 6c65 6 Not Acceptable
0430 3630 3620 4e6f 7420 4163 6365 7074 6162 606 Not Acceptab
0440 6c65 0d0a 613d 7479 7065 3a62 726f 6164 le..a=type:broad
0450 6361 7374 6f6e 6534 3933 2055 6e64 6563 castone493 Undec
0460 6970 6865 7261 626c 650d 0a4d 494d 452d ipherable..MIME-
0470 5665 7273 696f 6e3a 204d 6179 2034 3832 Version: May 482
0480 204c 6f6f 7020 4465 7465 6374 6564 0d0a Loop Detected..
0490 4f72 6761 6e69 7a61 7469 6f6e 3a20 4a75 Organization: Ju
04A0 6e20 6d6f 6465 2d63 6861 6e67 652d 6e65 n mode-change-ne
04B0 6967 6862 6f72 3d63 7269 7469 6361 6c65 ighbor=criticale
04C0 7274 6370 2d66 6234 3839 2042 6164 2045 rtcp-fb489 Bad E
04D0 7665 6e74 6c73 0d0a 556e 7375 7070 6f72 ventls..Unsuppor
04E0 7465 643a 204a 616e 2035 3032 2042 6164 ted: Jan 502 Bad
04F0 2047 6174 6577 6179 6d6f 6465 2d63 6861 Gatewaymode-cha
0500 6e67 652d 7065 7269 6f64 3d0d 0a61 3d6f nge-period=..a=o
0510 7269 656e 743a 7365 6173 6361 7065 0d0a rient:seascape..
0520 613d 7479 7065 3a6d 6f64 6572 6174 6564 a=type:moderated
0530 3430 3420 4e6f 7420 466f 756e 6433 3035 404 Not Found305
0540 2055 7365 2050 726f 7879 0d0a 613d 7479 Use Proxy..a=ty
0550 7065 3a72 6563 766f 6e6c 790d 0a61 3d74 pe:recvonly..a=t
0560 7970 653a 6d65 6574 696e 670d 0a6b 3d70 ype:meeting..k=p
0570 726f 6d70 743a 0d0a 5265 6665 7272 6564 rompt:..Referred
0580 2d42 793a 200d 0a49 6e2d 5265 706c 792d -By: ..In-Reply-
0590 546f 3a20 5452 5545 6e63 6f64 696e 673a To: TRUEncoding:
05A0 2031 3832 2051 7565 7565 6441 7574 6865 182 QueuedAuthe
05B0 6e74 6963 6174 653a 200d 0a55 7365 722d nticate: ..User-
05C0 4167 656e 743a 200d 0a61 3d66 7261 6d65 Agent: ..a=frame
05D0 7261 7465 3a0d 0a41 6c65 7274 2d49 6e66 rate:..Alert-Inf
05E0 6f3a 2043 414e 4345 4c20 0d0a 613d 6d61 o: CANCEL ..a=ma
05F0 7870 7469 6d65 3a3b 7265 7472 792d 6166 xptime:;retry-af
0600 7465 723d 7561 6368 616e 6e65 6c73 3d34 ter=uachannels=4
0610 3130 2047 6f6e 650d 0a52 6566 6572 2d54 10 Gone..Refer-T
0620 6f3a 200d 0a50 7269 6f72 6974 793a 200d o: ..Priority: .
0630 0a6d 3d63 6f6e 7472 6f6c 200d 0a61 3d71 .m=control ..a=q
0640 7561 6c69 7479 3a0d 0a61 3d73 6470 6c61 uality:..a=sdpla
0650 6e67 3a0d 0a61 3d63 6861 7273 6574 3a0d ng:..a=charset:.
0660 0a52 6570 6c61 6365 733a 2052 4546 4552 .Replaces: REFER
0670 2069 7073 6563 2d69 6b65 3b74 7261 6e73 ipsec-ike;trans
0680 706f 7274 3d0d 0a61 3d6b 6579 7764 733a port=..a=keywds:
0690 0d0a 6b3d 6261 7365 3634 3a3b 7265 6672 ..k=base64:;refr
06A0 6573 6865 723d 0d0a 613d 7074 696d 653a esher=..a=ptime:
06B0 0d0a 6b3d 636c 6561 723a 3b72 6563 6569 ..k=clear:;recei
06C0 7665 643d 3b64 7572 6174 696f 6e3d 0d0a ved=;duration=..
06D0 4163 6365 7074 3a20 0d0a 613d 6772 6f75 Accept: ..a=grou
06E0 703a 4641 4c53 453a 2049 4e46 4f20 0d0a p:FALSE: INFO ..
06F0 4163 6365 7074 2d0d 0a61 3d6c 616e 673a Accept-..a=lang:
0700 0d0a 6d3d 6461 7461 206d 6f64 652d 7365 ..m=data mode-se
0710 743d 0d0a 613d 746f 6f6c 3a54 4c53 756e t=..a=tool:TLSun
0720 2c20 0d0a 4461 7465 3a20 0d0a 613d 6361 , ..Date: ..a=ca
0730 743a 0d0a 6b3d 7572 693a 0d0a 5072 6f78 t:..k=uri:..Prox
0740 792d 3b72 6561 736f 6e3d 3b6d 6574 686f y-;reason=;metho
0750 643d 0d0a 613d 6d69 643a 3b6d 6164 6472 d=..a=mid:;maddr
0760 3d6f 7061 7175 653d 0d0a 4d69 6e2d 3b61 =opaque=..Min-;a
0770 6c67 3d4d 6f6e 2c20 5475 652c 2057 6564 lg=Mon, Tue, Wed
0780 2c20 4672 692c 2053 6174 2c20 3b74 746c , Fri, Sat, ;ttl
0790 3d61 7574 733d 0d0a 723d 0d0a 7a3d 0d0a =auts=..r=..z=..
07A0 653d 3b69 643d 0d0a 693d 6372 633d 0d0a e=;id=..i=crc=..
07B0 753d 3b71 3d75 6173 3431 3420 5265 7175 u=;q=uas414 Requ
07C0 6573 742d 5552 4920 546f 6f20 4c6f 6e67 est-URI Too Long
07D0 6976 6575 7072 6976 6163 7975 6470 7265 iveuprivacyudpre
07E0 6665 7236 3030 2042 7573 7920 4576 6572 fer600 Busy Ever
07F0 7977 6865 7265 7175 6972 6564 3438 3020 ywherequired480
0800 5465 6d70 6f72 6172 696c 7920 556e 6176 Temporarily Unav
0810 6169 6c61 626c 650d 0a61 3d74 7970 653a ailable..a=type:
0820 482e 3333 3230 3220 4163 6365 7074 6564 H.33202 Accepted
0830 0d0a 5365 7373 696f 6e2d 4578 7069 7265 ..Session-Expire
0840 733a 200d 0a53 7562 7363 7269 7074 696f s: ..Subscriptio
0850 6e2d 5374 6174 653a 204e 6f76 200d 0a53 n-State: Nov ..S
0860 6572 7669 6365 2d52 6f75 7465 3a20 5365 ervice-Route: Se
0870 7020 0d0a 416c 6c6f 772d 4576 656e 7473 p ..Allow-Events
0880 3a20 4665 6220 0d0a 613d 696e 6163 7469 : Feb ..a=inacti
0890 7665 5254 502f 5341 5650 2052 5450 2f41 veRTP/SAVP RTP/A
08A0 5650 4620 416e 6f6e 796d 6f75 7369 7073 VPF Anonymousips
08B0 3a0d 0a61 3d74 7970 653a 7465 7374 656c :..a=type:testel
08C0 3a4d 4553 5341 4745 200d 0a61 3d72 6563 :MESSAGE ..a=rec
08D0 766f 6e6c 790d 0a61 3d73 656e 646f 6e6c vonly..a=sendonl
08E0 790d 0a63 3d49 4e20 4950 3420 0d0a 5265 y..c=IN IP4 ..Re
08F0 6173 6f6e 3a20 0d0a 416c 6c6f 773a 200d ason: ..Allow: .
0900 0a45 7665 6e74 3a20 0d0a 5061 7468 3a20 .Event: ..Path:
0910 3b75 7365 723d 0d0a 623d 4153 2043 5420 ;user=..b=AS CT
0920 0d0a 5757 572d 4175 7468 656e 7469 6361 ..WWW-Authentica
0930 7465 3a20 4469 6765 7374 200d 0a61 3d73 te: Digest ..a=s
0940 656e 6472 6563 7669 6465 6f63 7465 742d endrecvideoctet-
0950 616c 6967 6e3d 6170 706c 6963 6174 696f align=applicatio
0960 6e2f 7364 7061 7468 6561 6465 7273 7061 n/sdpatheaderspa
0970 7574 683d 0d0a 613d 6f72 6965 6e74 3a70 uth=..a=orient:p
0980 6f72 7472 6169 7469 6d65 6f75 7474 722d ortraitimeouttr-
0990 696e 7469 636f 6e63 3d34 3833 2054 6f6f inticonc=483 Too
09A0 204d 616e 7920 486f 7073 6c69 6e66 6f70 Many Hopslinfop
09B0 7469 6f6e 616c 676f 7269 7468 6d3d 3630 tionalgorithm=60
09C0 3420 446f 6573 204e 6f74 2045 7869 7374 4 Does Not Exist
09D0 2041 6e79 7768 6572 6573 706f 6e73 653d Anywheresponse=
09E0 0d0a 0d0a 5265 7175 6573 742d 4469 7370 ....Request-Disp
09F0 6f73 6974 696f 6e3a 204d 4435 3830 2050 osition: MD580 P
0A00 7265 636f 6e64 6974 696f 6e20 4661 696c recondition Fail
0A10 7572 6570 6c61 6365 7334 3232 2053 6573 ureplaces422 Ses
0A20 7369 6f6e 2049 6e74 6572 7661 6c20 546f sion Interval To
0A30 6f20 536d 616c 6c6f 6361 6c31 3831 2043 o Smallocal181 C
0A40 616c 6c20 4973 2042 6569 6e67 2046 6f72 all Is Being For
0A50 7761 7264 6564 6f6d 6169 6e3d 6661 696c wardedomain=fail
0A60 7572 656e 6465 7265 616c 6d3d 5355 4253 urenderealm=SUBS
0A70 4352 4942 4520 7072 6563 6f6e 6469 7469 CRIBE preconditi
0A80 6f6e 6f72 6d61 6c69 7073 6563 2d6d 616e onormalipsec-man
0A90 6461 746f 7279 3431 3320 5265 7175 6573 datory413 Reques
0AA0 7420 456e 7469 7479 2054 6f6f 204c 6172 t Entity Too Lar
0AB0 6765 3265 3138 3320 5365 7373 696f 6e20 ge2e183 Session
0AC0 5072 6f67 7265 7373 6374 7034 3836 2042 Progressctp486 B
0AD0 7573 7920 4865 7265 6d6f 7465 726d 696e usy Heremotermin
0AE0 6174 6564 414b 4176 312d 4d44 352d 7365 atedAKAv1-MD5-se
0AF0 7373 696f 6e6f 6e65 0d0a 4175 7468 6f72 ssionone..Author
0B00 697a 6174 696f 6e3a 2036 3033 2044 6563 ization: 603 Dec
0B10 6c69 6e65 7874 6e6f 6e63 653d 3438 3520 linextnonce=485
0B20 416d 6269 6775 6f75 7365 726e 616d 653d Ambiguousername=
0B30 6175 6469 6f0d 0a43 6f6e 7465 6e74 2d54 audio..Content-T
0B40 7970 653a 204d 6172 200d 0a52 6563 6f72 ype: Mar ..Recor
0B50 642d 526f 7574 653a 204a 756c 2034 3031 d-Route: Jul 401
0B60 2055 6e61 7574 686f 7269 7a65 640d 0a52 Unauthorized..R
0B70 6571 7569 7265 3a20 0d0a 743d 3020 302e equire: ..t=0 0.
0B80 302e 302e 300d 0a53 6572 7665 723a 2052 0.0.0..Server: R
0B90 4547 4953 5445 5220 0d0a 633d 494e 2049 EGISTER ..c=IN I
0BA0 5036 2031 3830 2052 696e 6769 6e67 3130 P6 180 Ringing10
0BB0 3020 5472 7969 6e67 763d 300d 0a6f 3d55 0 Tryingv=0..o=U
0BC0 5044 4154 4520 4e4f 5449 4659 200d 0a53 PDATE NOTIFY ..S
0BD0 7570 706f 7274 6564 3a20 756e 6b6e 6f77 upported: unknow
0BE0 6e41 4d52 5450 2f41 5650 200d 0a50 7269 nAMRTP/AVP ..Pri
0BF0 7661 6379 3a20 0d0a 5365 6375 7269 7479 vacy: ..Security
0C00 2d0d 0a45 7870 6972 6573 3a20 0d0a 613d -..Expires: ..a=
0C10 7274 706d 6170 3a0d 0a6d 3d76 6964 656f rtpmap:..m=video
0C20 200d 0a6d 3d61 7564 696f 200d 0a73 3d20 ..m=audio ..s=
0C30 6661 6c73 650d 0a61 3d63 6f6e 663a 3b65 false..a=conf:;e
0C40 7870 6972 6573 3d0d 0a52 6f75 7465 3a20 xpires=..Route:
0C50 0d0a 613d 666d 7470 3a0d 0a61 3d63 7572 ..a=fmtp:..a=cur
0C60 723a 436c 6965 6e74 3a20 5665 7269 6679 r:Client: Verify
0C70 3a20 0d0a 613d 6465 733a 0d0a 5241 636b : ..a=des:..RAck
0C80 3a20 0d0a 5253 6571 3a20 4259 4520 636e : ..RSeq: BYE cn
0C90 6f6e 6365 3d31 3030 7265 6c75 7269 3d71 once=100reluri=q
0CA0 6f70 3d54 4350 5544 5071 6f73 786d 6c3b op=TCPUDPqosxml;
0CB0 6c72 0d0a 5669 613a 2053 4950 2f32 2e30 lr..Via: SIP/2.0
0CC0 2f54 4350 2034 3038 2052 6571 7565 7374 /TCP 408 Request
0CD0 2054 696d 656f 7574 696d 6572 7073 6970 Timeoutimerpsip
0CE0 3a0d 0a43 6f6e 7465 6e74 2d4c 656e 6774 :..Content-Lengt
0CF0 683a 204f 6374 200d 0a56 6961 3a20 5349 h: Oct ..Via: SI
0D00 502f 322e 302f 5544 5020 3b63 6f6d 703d P/2.0/UDP ;comp=
0D10 7369 6763 6f6d 7072 6f62 6174 696f 6e61 sigcomprobationa
0D20 636b 3b62 7261 6e63 683d 7a39 6847 3462 ck;branch=z9hG4b
0D30 4b0d 0a4d 6178 2d46 6f72 7761 7264 733a K..Max-Forwards:
0D40 2041 7072 2053 4354 5052 4143 4b20 494e Apr SCTPRACK IN
0D50 5649 5445 200d 0a43 616c 6c2d 4944 3a20 VITE ..Call-ID:
0D60 0d0a 436f 6e74 6163 743a 2032 3030 204f ..Contact: 200 O
0D70 4b0d 0a46 726f 6d3a 200d 0a43 5365 713a K..From: ..CSeq:
0D80 200d 0a54 6f3a 203b 7461 673d 0410 dd10 ..To: ;tag=....
0D90 1131 0d11 0a07 10b9 0c10 fe12 10e1 0611 .1..............
0DA0 4e07 114e 0311 4a04 114a 0710 b208 1179 N..N..J..J.....y
0DB0 0611 810f 1122 0b11 5506 116b 0b11 6013 ....."..U..k..`.
0DC0 10b2 0811 7105 1187 1310 f709 0e8d 080d ....q...........
0DD0 ae0c 10b9 0710 8e03 0d96 0310 8a04 108a ................
0DE0 090d d70a 0f12 080f 8f09 0f8f 080d 6c06 ..............l.
0DF0 0e66 090e 6c0a 0e6c 060f c607 0fc6 0511 .f..l..l........
0E00 4806 1148 060f bf07 0fbf 070e 5506 0f16 H..H........U...
0E10 040e f403 0eb1 0310 a609 1050 0310 a30a ...........P....
0E20 0db4 050e 3606 0ed6 030d f911 0ef8 040c ....6...........
0E30 d908 0eea 0409 5303 0a4b 040e e410 0f35 ......S..K.....5
0E40 090e e408 0d3f 030f e10b 1001 0310 ac06 .....?..........
0E50 1095 0c0e 760b 0feb 0a0f ae05 102b 0410 ....v........+..
0E60 2b08 107a 100f 4907 0fb8 0910 3e0b 100c +..z..I.....>...
0E70 070f 780b 0f6d 0910 4708 1082 0b0f f608 ..x..m..G.......
0E80 1062 080f 8708 106a 040f 780d 0fcd 080d .b.....j..x.....
0E90 ae10 0f5d 0b0f 9814 0d20 1b0d 2004 0de0 ...]..... .. ...
0EA0 140e b40b 0fa3 0b07 340f 0d56 040e f403 ........4..V....
0EB0 10af 070d 3409 0f27 0410 9b04 109f 0910 ....4..'........
0EC0 5908 1072 0910 350a 1021 0a10 1708 0fe3 Y..r..5..!......
0ED0 0310 a905 0cac 040c bd07 0cc1 080c c109 ................
0EE0 0cf6 100c 720c 0c86 040d 640c 0cd5 090c ....r.....d.....
0EF0 ff1b 0bfc 110c 5d13 0c30 090c a40c 0c24 ......]..0.....$
0F00 0c0d 3b03 0d1a 030d 1d16 0c43 090c 9209 ..;........C....
0F10 0c9b 0d0e cb04 0d16 060d 1005 04f2 0b0c ................
0F20 e105 0bde 0a0c ec13 0be3 070b d408 0d08 ................
0F30 0c0c c909 0c3a 040a e50c 0a23 080b 3a0e .....:.....#..:.
0F40 09ab 0f0e fa09 0f6f 0c0a 170f 0976 0c0a .......o.....v..
0F50 5f17 0de2 0f07 a80a 0f85 0f08 d60e 09b9 _...............
0F60 0b0a 7a03 0bdb 0308 c104 0ec7 0308 d302 ..z.............
0F70 048d 080b 4a05 0b8c 070b 6106 0548 0407 ....J.....a..H..
0F80 f405 1030 0407 1e08 071e 050b 9110 04ca ...0............
0F90 090a 7109 0e87 0504 9805 0b6e 0b04 9b0f ..q........n....
0FA0 049b 0704 9b03 04a3 0704 a310 0798 0907 ................
0FB0 9805 0b73 050b 7805 0b7d 0507 b905 0b82 ...s..x..}......
0FC0 050b 8705 0b1d 0508 e405 0c81 050f 4405 ..............D.
0FD0 1140 0508 7805 089d 050f 5805 073f 050c .@..x.....X..?..
0FE0 6d05 10f2 050c 5805 06a9 0407 b609 058c m.....X.........
0FF0 0606 1a06 0e81 0a06 160a 0ac4 070b 5a0a ..............Z.
1000 0aba 030b 1b04 1145 060c 8c07 05ad 0a0e .......E........
1010 da08 0b42 0d09 f70b 051c 0911 1608 05c9 ...B............
1020 070d 8606 0bcf 0a06 4d04 0ba2 0606 8d08 ........M.......
1030 05e6 080e 110b 0a9b 030a 0403 0bb5 0510 ................
1040 d704 0994 050a e203 0bb2 060d 6704 0d11 ............g...
1050 0808 b71b 0e3b 0a09 a114 0485 1507 8315 .....;..........
1060 076e 0d09 3d17 06ae 0f07 e614 07be 0d06 .n..=...........
1070 0a0d 0930 1606 f212 081e 2104 aa13 10c5 ...0......!.....
1080 080a 0f1c 0e96 180b b81a 0595 1a05 7511 ..............u.
1090 063d 1606 dc1e 0e19 1605 d11d 0620 2305 .=........... #.
10A0 2711 087d 110d 9916 04da 0d0f 1c16 0708 '..}............
10B0 1705 b40d 08c7 1307 f812 0857 1f04 fe19 ...........W....
10C0 054e 1308 0b0f 08e9 1706 c513 067b 1905 .N...........{..
10D0 f115 0744 180d fb0b 0f09 1b0d be12 0830 ...D...........0
10E0 1507 5904 0ba6 040b ae04 0b9e 040b 9604 ..Y.............
10F0 0b9a 0a0a b00b 0a90 080b 320b 096b 080b ..........2..k..
1100 2a0b 0a85 090b 120a 0aa6 0d09 ea13 0d74 *..............t
1110 1407 d213 090b 1208 4210 095b 1209 1e0d ........B..[....
1120 0cb1 0e0c 1711 094a 0c0a 530c 0a47 090a .......J..S..G..
1130 f70e 09c7 0c0a 3b07 0669 0806 6906 09e3 ......;..i..i...
1140 080b 520a 0ad8 1206 570d 0657 0709 e304 ..R.....W..W....
1150 0ae9 1007 3009 0b00 0c0a 2f05 0ae9 050a ....0...../.....
1160 6b06 0a6b 0a0a ce09 0aee 030b db07 0f7e k..k...........~
1170 0a09 970a 0671 0e09 d517 0693 070e 5c07 .....q........\.
1180 0fda 0a0f 350d 0dec 0a09 970a 0671 080b ....5........q..
1190 220f 0985 060b 680c 0d4a 090b 0913 08f8 ".....h..J......
11A0 1508 a204 0baa 0f05 660d 0723 090a 060b ........f..#....
11B0 0d4a 0f04 ee06 04f8 0409 2b04 0853 0708 .J........+..S..
11C0 c003 111f 0411 1e07 0d8c 0307 3404 10db ............4...
11D0 0307 3603 0da9 0d04 200b 0451 0c04 3a04 ..6..... ..Q..:.
11E0 0bb8 040c 2404 0595 0404 7c04 0575 0404 ....$.....|..u..
11F0 8504 096b 0406 3d06 047b 0406 dc04 0783 ...k..=..{......
1200 040e 1912 0400 1008 8e10 0869 0e04 120d ...........i....
1210 042d 0310 b904 05d1 0407 6e04 0620 0704 .-........n.. ..
1220 7404 0bfc 0a04 5c04 0527 0409 3d04 087d t.....\..'..=..}
1230 040f ae04 0d99 0406 ae04 04da 0904 0908 ................
1240 1122 040f 1c04 07e6 040e cb05 08bd 0407 ."..............
1250 0804 0fa3 0406 5704 05b4 040f 5d04 08c7 ......W.....]...
1260 080b f404 07f8 0407 3004 07be 0408 5705 ........0.....W.
1270 0d46 0404 fe04 060a 0405 4e04 0e3b 0408 .F........N..;..
1280 0b04 0930 0408 e905 05ee 0406 c504 06f2 ...0............
1290 0406 7b04 09a1 0405 f104 081e 0407 4404 ..{...........D.
12A0 0bdd 040d fb04 04aa 040b e307 0eee 040f ................
12B0 0904 0eb4 040d be04 10c5 0408 3005 0f30 ............0..0
12C0 0407 5904 0a0f 060e 6104 0481 040d ab04 ..Y.....a.......
12D0 0d93 0411 6b04 0e96 0504 6609 046b 0b04 ....k.....f..k..
12E0 4604 0ce1 F...
Table 1: binary representation of the static SIP/SDP
dictionary for SigComp
4. Security Considerations
The security considerations of [1] apply. This memo does not
introduce any known additional security risk.
5. IANA Considerations
None.
6. Acknowledgements
The authors would like to thank Lars-Erik Jonsson, Zhigang C. Liu and
Jonathan Rosenberg for their valuable comments.
7. References
7.1 Normative References
[1] Price, R., Bormann, C., Christoffersson, J., Hannu, H., Liu, Z.
and J. Rosenberg, "Signaling Compression (SigComp)", RFC3320,
January 2003.
[2] Bradner, S., "Key words for use in RFCs to indicate requirement
levels", BCP 14, RFC2119, March 1997.
7.2 Informative References
[3] Rosenberg, J., Schulzrinne, H., Camarillo, G., Johnston, A.,
Peterson, J., Sparks, R., Handley, M. and E. Schooler, "SIP:
Session Initiation Protocol", RFC3261, June 2002.
[4] Garcia-Martin, M., "3rd-Generation Partnership Project (3GPP)
Release 5 requirements on the Session Initiation Protocol
(SIP)", Work in Progress.
[5] Yergeau, F., "UTF-8, a transformation format of ISO 10646", RFC
2279, January 1998.
[6] Franks, J., Hallam-Baker, P., Hostetler, J., Lawrence, S.,
Leach, P., Luotonen, A. and L. Stewart, "HTTP Authentication:
Basic and Digest Access Authentication", RFC2617, June 1999.
[7] Vaha-Sipila, A., "URLs for telephone calls", RFC2806, April
2000.
[8] Donovan, S., "The SIP INFO Method", RFC2976, October 2000.
[9] Roach, A. B., "Session Initiation Protocol (SIP)-Specific Event
Notification", RFC3265, June 2002.
[10] Rosenberg, J. and H. Schulzrinne, "Reliability of Provisional
Responses in Session Initiation Protocol (SIP)", RFC3262, June
2002.
[11] Rosenberg, J., "The Session Initiation Protocol UPDATE Method",
RFC3311, October 2002.
[12] Camarillo, G., Ed., Marshall, W., Ed. and J. Rosenberg,
"Integration of Resource Management and Session Initiation
Protocol (SIP)", RFC3312, October 2002.
[13] Sparks, R., "The SIP Refer Method", Work in Progress.
[14] Mahy, R., Biggs, B. and R. Dean, "The Session Initiation
Protocol (SIP) "Replaces" Header", Work in Progress.
[15] Sparks, R., "Internet Media Type message/sipfrag", RFC3420,
November 2002.
[16] Willis, D. and B. Hoeneisen, "Session Initiation Protocol (SIP)
Extension Header Field for Registering Non-Adjacent Contacts",
RFC3327, December 2002.
[17] Schulzrinne, H., Oran, D. and G. Camarillo, "The Reason Header
Field for the Session Initiation Protocol (SIP)", RFC3326,
December 2002.
[18] Donovan, S., and J. Rosenberg, "Session Timers in the Session
Initiation Protocol (SIP)", Work in Progress.
[19] Niemi, A., Arkko, J. and V. Torvinen , "Hypertext Transfer
Protocol (HTTP) Digest Authentication Using Authentication and
Key Agreement (AKA)", RFC3310, September 2002.
[20] Arkko, J., Torvinen, V., Camarillo, G., Niemi A. and T. Haukka,
"Security Mechanism Agreement for the Session Initiation
Protocol (SIP)", RFC3329, January 2003.
[21] Campbell, B., Rosenberg, J., Schulzrinne, H., Huitema, C. and
D. Gurle, "Session Initiation Protocol (SIP) Extension for
Instant Messaging", RFC3428, December 2002.
[22] Schulzrinne, H. and J. Rosenberg, "Session Initiation Protocol
(SIP) Caller Preferences and Callee Capabilities", Work in
Progress.
[23] Camarillo, G., "Compressing the Session Initiation Protocol
(SIP)", RFC3486, February 2003.
[24] Handley, M., Jacobson, V. and C. Perkins, "SDP: Session
Description Protocol", Work in Progress.
[25] Sjoberg, J., Westerlund, M., Lakaniemi, A. and Q. Xie, "Real-
Time Transport Protocol payload format and file storage format
for the Adaptive Multi-Rate (AMR) and Adaptive Multi-Rate
Wideband (AMR-WB) audio codecs", RFC3267, June 2002.
[26] Camarillo, G., Eriksson, G., Holler, J. and H. Schulzrinne,
"Grouping of Media Lines in the Session Description Protocol
(SDP)", RFC3388, December 2002.
[27] Schulzrinne, H. and S. Petrack, "RTP Payload for DTMF Digits,
Telephony Tones and Telephony Signals", RFC2833, May 2000.
[28] Arkko, J., Carrara, E., Lindholm, F., Naslund, M. and K.
Norrman, "Key Management Extensions for SDP and RTSP", Work in
Progress.
[29] Arkko, J., Carrara, E., Lindholm, F., Naslund, M. and K.
Norrman, "MIKEY: Multimedia Internet KEYing", Work in
Progress.
[30] Baugher, M., Blom, R., Carrara, E., McGrew, D., Naslund, M.,
Norrman, K. and D. Oran, "The Secure Real Time Transport
Protocol", Work in Progress.
[31] Ott, J., Wenger, S., Fukunaga, S., Sato, N., Burmeister, C.,
and Rey, J., "Extended RTP Profile for RTCP-based feedback
(RTP/AVPF)", Work in Progress.
[32] Rosenberg, J. and H. Schulzrinne, "An Offer/Answer Model with
Session Description Protocol (SDP)", RFC3264, June 2002.
[33] Peterson, J., "A Privacy Mechanism for the Session Initiation
Protocol (SIP)", RFC3323, November 2002.
[34] Sparks, R., "The Referred-By mechanism", Work in Progress.
[35] Willis, D. and B. Hoeneisen, "Session Initiation Protocol
Extension Header Field for Service Route Discovery During
Registration", Work in Progress.
Appendix A. SIP input strings to the SIP/SDP static dictionary
For reference, this section lists the SIP input strings that were
used in generating the dictionary, as well as a priority value, the
offset of the string in the generated dictionary, the length of the
string, and one or more references into the referenced documents that
motivate the presence of this string. Note that the notation
"[CRLF]" stands for a sequence of two bytes with the values 0x0d and
0x0a, respectively.
The priority value is used for determining the position of the string
in the dictionary. Lower priority values (higher priorities) cause
the string to occur at a later position in the dictionary, making it
more efficient to reference the string in certain compression
algorithms. Hence, lower priority values were assigned to strings
more likely to occur.
String Pr Off Len References
===================================== == ==== ==== ==========
"sip:" 1 0CDD 0004 [3] 19.1.1
"sips:" 3 08AC 0005 [3] 19.1.1
"tel:" 3 08BD 0004 [7] 2.2
"SIP/2.0" 1 0CB9 0007 [3] 25.1
"SIP/2.0/UDP " 1 0CFE 000C [3] 25.1
"SIP/2.0/TCP " 2 0CB9 000C [3] 25.1
"INVITE" 1 0D4E 0006 [3] 25.1
"INVITE " 1 0D4E 0007 [3] 25.1
"ACK" 1 0D4A 0003 [3] 25.1
"ACK " 1 0D4A 0004 [3] 25.1
"OPTIONS" 4 0269 0007 [3] 25.1
"OPTIONS " 4 0269 0008 [3] 25.1
"BYE" 2 0C8A 0003 [3] 25.1
"BYE " 2 0C8A 0004 [3] 25.1
"CANCEL" 4 05E3 0006 [3] 25.1
"CANCEL " 4 05E3 0007 [3] 25.1
"REGISTER" 2 0B8F 0008 [3] 25.1
"REGISTER " 2 0B8F 0009 [3] 25.1
"INFO" 4 06E9 0004 [8] 2
"INFO " 4 06E9 0005 [8] 2
"SUBSCRIBE" 2 0A6C 0009 [9] 8.1.1
"SUBSCRIBE " 2 0A6C 000A [9] 8.1.1
"NOTIFY" 2 0BC6 0006 [9] 8.1.2
"NOTIFY " 2 0BC6 0007 [9] 8.1.2
"PRACK" 2 0D48 0005 [10] 6
"PRACK " 2 0D48 0006 [10] 6
"UPDATE" 2 0BBF 0006 [11] 7, 10
"UPDATE " 2 0BBF 0007 [11] 7, 10
"REFER" 4 066B 0005 [13] 2.1, 7
"REFER " 4 066B 0006 [13] 2.1, 7
"MESSAGE" 3 08C1 0007 [21] 9
"MESSAGE " 3 08C1 0008 [21] 9
"[CRLF]Accept: " 4 06CE 000A [3] 20.1
"[CRLF]Accept-" 4 06EE 0009 [22] 5,
[3] 20.2, 20.3
"Contact: " 5 0009 0009 [22] 5
"Encoding: " 4 0597 000A [3] 20.2,
[3] 20.12
"Language: " 4 0271 000A [3] 20.3,
[3] 20.13
"[CRLF]Alert-Info: " 4 05D5 000E [3] 20.4
"[CRLF]Allow: " 3 08F6 0009 [3] 20.5
"[CRLF]Allow-Events: " 3 0872 0010 [9] 8.2.1
"[CRLF]Authentication-Info: " 4 0293 0017 [3] 20.6
"[CRLF]Authorization: " 2 0AF8 0011 [3] 20.7
"[CRLF]Call-ID: " 1 0D55 000B [3] 20.8
"[CRLF]Call-Info: " 5 002D 000D [3] 20.9
"[CRLF]Contact: " 1 0D60 000B [3] 20.10
"[CRLF]Content-" 4 0B35 000A [3] 20.11,
20.12, 20.13, [3] 20.14,
20.15
"Disposition: " 4 09EC 000D [3] 20.11
"Encoding: " 4 0597 000A [3] 20.2,
[3] 20.12
"Language: " 4 0271 000A [3] 20.3,
[3] 20.13
"[CRLF]Content-Length: " 1 0CE1 0012 [3] 20.14
"[CRLF]Content-Type: " 2 0B35 0010 [3] 20.15
"[CRLF]CSeq: " 1 0D79 0008 [3] 20.16
"[CRLF]Date: " 4 0722 0008 [3] 20.17
"[CRLF]Error-Info: " 5 0012 000E [3] 20.18
"[CRLF]Event: " 3 08FF 0009 [9] 8.2.1
"[CRLF]Expires: " 2 0C01 000B [3] 20.19
"[CRLF]From: " 1 0D71 0008 [3] 20.20
"[CRLF]In-Reply-To: " 4 0585 000F [3] 20.21
"[CRLF]Max-Forwards: " 1 0D31 0010 [3] 20.22
"[CRLF]Min-" 4 0768 0006 [3] 20.23,
[18] 5
"Expires: " 4 083A 0009 [3] 20.23
"SE: " 4 06E5 0004 [18] 5
"[CRLF]MIME-Version: " 5 0469 0010 [3] 20.24
"[CRLF]Organization: " 5 048E 0010 [3] 20.25
"[CRLF]Path: " 3 0908 0008 [16] 3
"[CRLF]Priority: " 4 0623 000C [3] 20.26
"[CRLF]Privacy: " 2 0BEB 000B [33] 4.2
"[CRLF]Proxy-" 4 073A 0008 [3] 20.27,
20.28, 20.29
"Authenticate: " 4 05AB 000E [3] 20.27
"Authorization: " 4 0AFA 000F [3] 20.28
"Require: " 4 0B6F 0009 [3] 20.29
"[CRLF]RAck: " 2 0C7A 0008 [10] 7.2
"[CRLF]Reason: " 3 08EC 000A [17] 2
"[CRLF]Record-Route: " 2 0B49 0010 [3] 20.30
"[CRLF]Refer-To: " 4 0617 000C [13] 2.1, 7
"[CRLF]Referred-By: " 4 0576 000F [34] 9
"[CRLF]Reject-Contact: " 5 0000 0012 [22] 5
"[CRLF]Replaces: " 4 065F 000C [14] 3.1
"[CRLF]Reply-To: " 5 003A 000C [3] 20.31
"[CRLF]Request-Disposition: " 4 09E2 0017 [22] 5
"[CRLF]Require: " 2 0B6D 000B [3] 20.32
"[CRLF]Retry-After: " 4 03A8 000F [3] 20.33
"[CRLF]Route: " 2 0C47 0009 [3] 20.34
"[CRLF]RSeq: " 2 0C82 0008 [10] 7.1
"[CRLF]Security-" 2 0BF6 000B [20] 3.3
"Client: " 2 0C62 0008 [20] 3.3
"Server: " 2 0B87 0008 [20] 3.3
"Verify: " 2 0C6A 0008 [20] 3.3
"[CRLF]Server: " 4 0B85 000A [3] 20.35
"[CRLF]Service-Route: " 3 085D 0011 [35]
"[CRLF]Session-Expires: " 3 0830 0013 [18] 4
"[CRLF]Subject: " 5 0051 000B [3] 20.36
"[CRLF]Subscription-State: " 3 0843 0016 [9] 8.2.3
"[CRLF]Supported: " 2 0BCD 000D [3] 20.37
"[CRLF]Timestamp: " 5 0020 000D [3] 20.38
"[CRLF]To: " 1 0D81 0006 [3] 20.39
"[CRLF]Unsupported: " 4 04D6 000F [3] 20.40
"[CRLF]User-Agent: " 4 05B9 000E [3] 20.41
"[CRLF]Via: " 1 0CB2 0007 [3] 20.42
"[CRLF]Via: SIP/2.0/UDP " 1 0CF7 0013 [3] 20.42
"[CRLF]Via: SIP/2.0/TCP " 1 0CB2 0013 [3] 20.42
"[CRLF]Warning: " 5 0046 000B [3] 20.43
"[CRLF]WWW-Authenticate: " 2 0920 0014 [3] 20.44
"[CRLF]WWW-Authenticate: Digest " 2 0920 001B [3] 20.44
"[CRLF][CRLF]" 2 09E0 0004 [3] 7
";transport=" 4 067A 000B [3] 25.1
"udp" 4 07DB 0003 [3] 25.1,
[24] A, [3] 25.1, [24] A
"tcp" 4 04C1 0003 [3] 25.1
"sctp" 4 0AC7 0004 [3] 25.1
"tls" 4 04D3 0003 [3] 25.1,
[20] 3.3
";user=" 3 0910 0006 [3] 25.1
"phone" 3 00F2 0005 [3] 25.1
"ip" 4 008D 0002 [3] 25.1
";method=" 4 074A 0008 [3] 25.1
";ttl=" 4 078C 0005 [3] 25.1
";lr" 2 0CAF 0003 [3] 25.1
"Digest " 2 0934 0007 [6] 3.2.1,
3.2.2
"username=" 2 0B27 0009 [6] 3.2.2
"uri=" 2 0C9B 0004 [6] 3.2.2
"qop=" 2 0C9F 0004 [6] 3.2.1,
3.2.2
"cnonce=" 2 0C8E 0007 [6] 3.2.2
"nc=" 2 0996 0003 [6] 3.2.2
"response=" 2 09D7 0009 [6] 3.2.2
"nextnonce=" 2 0B12 000A [6] 3.2.3
"rspauth=" 2 096C 0008 [6] 3.2.3
"realm=" 2 0A66 0006 [6] 3.2.1
"domain=" 2 0A55 0007 [6] 3.2.1
"nonce=" 2 0B16 0006 [6] 3.2.1
"opaque=" 4 0761 0007 [6] 3.2.1
"stale=" 4 0148 0006 [6] 3.2.1
"true" 4 03F4 0004 [6] 3.2.1
"false" 4 0C30 0005 [6] 3.2.1
"algorithm=" 2 09B4 000A [6] 3.2.1,
[19] 3.1
"MD5" 2 09F9 0003 [6] 3.2.1,
[19] 3.1
"MD5-sess" 2 0AEA 0008 [6] 3.2.1,
[19] 3.1
"auth" 4 031E 0004 [6] 3.2.1
"auth-int" 4 031E 0008 [6] 3.2.1
"AKAv" 2 0AE4 0004 [19] 3.1, 6
"AKAv1-MD5" 2 0AE4 0009 [19] 3.1, 6
"auts=" 4 0791 0005 [19] 3.4
"digest-integrity" 4 00CA 0010 [20] 3.3
"ipsec-ike" 4 0671 0009 [20] 3.3
"ipsec-man" 4 0A87 0009 [20] 3.3
"smime" 4 0098 0005 [20] 3.3
";alg=" 4 076E 0005 [20] 3.3
";purpose=" 5 006B 0009 [3] 20.9
"icon" 5 0993 0004 [3] 20.9, 20.11
"info" 5 09AB 0004 [3] 20.9
"card" 5 0081 0004 [3] 20.9
";expires=" 2 0C3E 0009 [3] 25.1,
[9] 8.4
"render" 5 0A61 0006 [3] 20.11
"session" 5 0AEE 0007 [3] 20.11,
[33] 4.2
"alert" 5 04BD 0005 [3] 20.11
";handling=" 5 005C 000A [3] 20.11
"optional" 2 09AE 0008 [3] 20.11,
[12] 4, [3] 20.11, [12] 4
"required" 5 07F4 0008 [3] 20.11
"text" 5 007C 0004 [3] 25.1
"image" 5 0066 0005 [3] 25.1
"audio" 5 0B30 0005 [3] 25.1
"video" 5 0946 0005 [3] 25.1
"application" 2 0334 000B [3] 25.1
"application/sdp" 2 0956 000F [3] 25.1
"message/sip" 4 009B 000B [3] 27.5
"message/sipfrag" 4 009B 000F [15] 2
"message" 4 009B 0007 [3] 27.5,
[15] 2
"sip" 4 00A3 0003 [3] 27.5
"sipfrag" 4 00A3 0007 [15] 2
"multipart/signed" 4 0398 0010 [3] 23.3
"multipart" 4 0398 0009 [3] 25.1, 7.4.1
"sdp" 2 064B 0003
"xml" 2 0CAC 0003
"Mon, " 4 0773 0005 [3] 25.1
"Tue, " 4 0778 0005 [3] 25.1
"Wed, " 4 077D 0005 [3] 25.1
"Thu, " 4 03B9 0005 [3] 25.1
"Fri, " 4 0782 0005 [3] 25.1
"Sat, " 4 0787 0005 [3] 25.1
"Sun, " 4 071D 0005 [3] 25.1
" Jan " 4 04E4 0005 [3] 25.1
" Feb " 4 0881 0005 [3] 25.1
" Mar " 4 0B44 0005 [3] 25.1
" Apr " 4 0D40 0005 [3] 25.1
" May " 4 0478 0005 [3] 25.1
" Jun " 4 049D 0005 [3] 25.1
" Jul " 4 0B58 0005 [3] 25.1
" Aug " 4 033F 0005 [3] 25.1
" Sep " 4 086D 0005 [3] 25.1
" Oct " 4 0CF2 0005 [3] 25.1
" Nov " 4 0858 0005 [3] 25.1
" Dec " 4 02A9 0005 [3] 25.1
" GMT" 4 03B6 0004 [3] 25.1
";tag=" 1 0D87 0005 [3] 25.1
"emergency" 4 018C 0009 [3] 20.26
"urgent" 4 021A 0006 [3] 20.26
"normal" 4 0A81 0006 [3] 20.26
"non-urgent" 4 0216 000A [3] 20.26
";duration=" 4 06C4 000A [3] 20.33
";maddr=" 4 075A 0007 [3] 20.42
";received=" 4 06BA 000A [3] 20.42
";branch=" 5 0D22 0008 [3] 20.42
";branch=z9hG4bK" 1 0D22 000F [3] 8.1.1.7
"SIP" 5 0CB9 0003 [3] 25.1,
[17] 2
"UDP" 2 0CA6 0003 [3] 20.42
"TCP" 2 0CA3 0003 [3] 20.42
"TLS" 4 071B 0003 [3] 20.42
"SCTP" 4 0D45 0004 [3] 20.42
"active" 4 088C 0006 [9] 8.4
"pending" 4 01AD 0007 [9] 8.4
"terminated" 4 0ADA 000A [9] 8.4
";reason=" 4 0742 0008 [9] 8.4
";retry-after=" 4 05F7 000D [9] 8.4
"deactivated" 4 011C 000B [9] 8.4
"probation" 4 0D16 0009 [9] 8.4
"rejected" 4 01C9 0008 [9] 8.4