RFC 3261
SIP: Session Initiation Protocol
Pages: 269
Proposed Standard
→ Errata
Obsoletes: 2543
Updated by: 3265 3853 4320 4916 5393 5621 5626 5630 5922 5954 6026 6141 6665 6878 7462 7463 8217 8591 8760 8898 8996
Proposed Standard
→ Errata
Obsoletes: 2543
Updated by: 3265 3853 4320 4916 5393 5621 5626 5630 5922 5954 6026 6141 6665 6878 7462 7463 8217 8591 8760 8898 8996
Part 11 of 13 – Pages 213 to 232
24 Examples
In the following examples, we often omit the message body and the corresponding Content-Length and Content-Type header fields for brevity.24.1 Registration
Bob registers on start-up. The message flow is shown in Figure 9. Note that the authentication usually required for registration is not shown for simplicity. biloxi.com Bob's registrar softphone | | | REGISTER F1 | |<---------------| | 200 OK F2 | |--------------->| Figure 9: SIP Registration Example F1 REGISTER Bob -> Registrar REGISTER sip:registrar.biloxi.com SIP/2.0 Via: SIP/2.0/UDP bobspc.biloxi.com:5060;branch=z9hG4bKnashds7 Max-Forwards: 70 To: Bob <sip:bob@biloxi.com> From: Bob <sip:bob@biloxi.com>;tag=456248 Call-ID: 843817637684230@998sdasdh09 CSeq: 1826 REGISTER Contact: <sip:bob@192.0.2.4> Expires: 7200 Content-Length: 0
The registration expires after two hours. The registrar responds with a 200 OK: F2 200 OK Registrar -> Bob SIP/2.0 200 OK Via: SIP/2.0/UDP bobspc.biloxi.com:5060;branch=z9hG4bKnashds7 ;received=192.0.2.4 To: Bob <sip:bob@biloxi.com>;tag=2493k59kd From: Bob <sip:bob@biloxi.com>;tag=456248 Call-ID: 843817637684230@998sdasdh09 CSeq: 1826 REGISTER Contact: <sip:bob@192.0.2.4> Expires: 7200 Content-Length: 024.2 Session Setup
This example contains the full details of the example session setup in Section 4. The message flow is shown in Figure 1. Note that these flows show the minimum required set of header fields - some other header fields such as Allow and Supported would normally be present. F1 INVITE Alice -> atlanta.com proxy INVITE sip:bob@biloxi.com SIP/2.0 Via: SIP/2.0/UDP pc33.atlanta.com;branch=z9hG4bKnashds8 Max-Forwards: 70 To: Bob <sip:bob@biloxi.com> From: Alice <sip:alice@atlanta.com>;tag=1928301774 Call-ID: a84b4c76e66710 CSeq: 314159 INVITE Contact: <sip:alice@pc33.atlanta.com> Content-Type: application/sdp Content-Length: 142 (Alice's SDP not shown)
F2 100 Trying atlanta.com proxy -> Alice SIP/2.0 100 Trying Via: SIP/2.0/UDP pc33.atlanta.com;branch=z9hG4bKnashds8 ;received=192.0.2.1 To: Bob <sip:bob@biloxi.com> From: Alice <sip:alice@atlanta.com>;tag=1928301774 Call-ID: a84b4c76e66710 CSeq: 314159 INVITE Content-Length: 0 F3 INVITE atlanta.com proxy -> biloxi.com proxy INVITE sip:bob@biloxi.com SIP/2.0 Via: SIP/2.0/UDP bigbox3.site3.atlanta.com;branch=z9hG4bK77ef4c2312983.1 Via: SIP/2.0/UDP pc33.atlanta.com;branch=z9hG4bKnashds8 ;received=192.0.2.1 Max-Forwards: 69 To: Bob <sip:bob@biloxi.com> From: Alice <sip:alice@atlanta.com>;tag=1928301774 Call-ID: a84b4c76e66710 CSeq: 314159 INVITE Contact: <sip:alice@pc33.atlanta.com> Content-Type: application/sdp Content-Length: 142 (Alice's SDP not shown) F4 100 Trying biloxi.com proxy -> atlanta.com proxy SIP/2.0 100 Trying Via: SIP/2.0/UDP bigbox3.site3.atlanta.com;branch=z9hG4bK77ef4c2312983.1 ;received=192.0.2.2 Via: SIP/2.0/UDP pc33.atlanta.com;branch=z9hG4bKnashds8 ;received=192.0.2.1 To: Bob <sip:bob@biloxi.com> From: Alice <sip:alice@atlanta.com>;tag=1928301774 Call-ID: a84b4c76e66710 CSeq: 314159 INVITE Content-Length: 0
F5 INVITE biloxi.com proxy -> Bob INVITE sip:bob@192.0.2.4 SIP/2.0 Via: SIP/2.0/UDP server10.biloxi.com;branch=z9hG4bK4b43c2ff8.1 Via: SIP/2.0/UDP bigbox3.site3.atlanta.com;branch=z9hG4bK77ef4c2312983.1 ;received=192.0.2.2 Via: SIP/2.0/UDP pc33.atlanta.com;branch=z9hG4bKnashds8 ;received=192.0.2.1 Max-Forwards: 68 To: Bob <sip:bob@biloxi.com> From: Alice <sip:alice@atlanta.com>;tag=1928301774 Call-ID: a84b4c76e66710 CSeq: 314159 INVITE Contact: <sip:alice@pc33.atlanta.com> Content-Type: application/sdp Content-Length: 142 (Alice's SDP not shown) F6 180 Ringing Bob -> biloxi.com proxy SIP/2.0 180 Ringing Via: SIP/2.0/UDP server10.biloxi.com;branch=z9hG4bK4b43c2ff8.1 ;received=192.0.2.3 Via: SIP/2.0/UDP bigbox3.site3.atlanta.com;branch=z9hG4bK77ef4c2312983.1 ;received=192.0.2.2 Via: SIP/2.0/UDP pc33.atlanta.com;branch=z9hG4bKnashds8 ;received=192.0.2.1 To: Bob <sip:bob@biloxi.com>;tag=a6c85cf From: Alice <sip:alice@atlanta.com>;tag=1928301774 Call-ID: a84b4c76e66710 Contact: <sip:bob@192.0.2.4> CSeq: 314159 INVITE Content-Length: 0 F7 180 Ringing biloxi.com proxy -> atlanta.com proxy SIP/2.0 180 Ringing Via: SIP/2.0/UDP bigbox3.site3.atlanta.com;branch=z9hG4bK77ef4c2312983.1 ;received=192.0.2.2 Via: SIP/2.0/UDP pc33.atlanta.com;branch=z9hG4bKnashds8 ;received=192.0.2.1 To: Bob <sip:bob@biloxi.com>;tag=a6c85cf From: Alice <sip:alice@atlanta.com>;tag=1928301774 Call-ID: a84b4c76e66710 Contact: <sip:bob@192.0.2.4> CSeq: 314159 INVITE Content-Length: 0
F8 180 Ringing atlanta.com proxy -> Alice SIP/2.0 180 Ringing Via: SIP/2.0/UDP pc33.atlanta.com;branch=z9hG4bKnashds8 ;received=192.0.2.1 To: Bob <sip:bob@biloxi.com>;tag=a6c85cf From: Alice <sip:alice@atlanta.com>;tag=1928301774 Call-ID: a84b4c76e66710 Contact: <sip:bob@192.0.2.4> CSeq: 314159 INVITE Content-Length: 0 F9 200 OK Bob -> biloxi.com proxy SIP/2.0 200 OK Via: SIP/2.0/UDP server10.biloxi.com;branch=z9hG4bK4b43c2ff8.1 ;received=192.0.2.3 Via: SIP/2.0/UDP bigbox3.site3.atlanta.com;branch=z9hG4bK77ef4c2312983.1 ;received=192.0.2.2 Via: SIP/2.0/UDP pc33.atlanta.com;branch=z9hG4bKnashds8 ;received=192.0.2.1 To: Bob <sip:bob@biloxi.com>;tag=a6c85cf From: Alice <sip:alice@atlanta.com>;tag=1928301774 Call-ID: a84b4c76e66710 CSeq: 314159 INVITE Contact: <sip:bob@192.0.2.4> Content-Type: application/sdp Content-Length: 131 (Bob's SDP not shown) F10 200 OK biloxi.com proxy -> atlanta.com proxy SIP/2.0 200 OK Via: SIP/2.0/UDP bigbox3.site3.atlanta.com;branch=z9hG4bK77ef4c2312983.1 ;received=192.0.2.2 Via: SIP/2.0/UDP pc33.atlanta.com;branch=z9hG4bKnashds8 ;received=192.0.2.1 To: Bob <sip:bob@biloxi.com>;tag=a6c85cf From: Alice <sip:alice@atlanta.com>;tag=1928301774 Call-ID: a84b4c76e66710 CSeq: 314159 INVITE Contact: <sip:bob@192.0.2.4> Content-Type: application/sdp Content-Length: 131 (Bob's SDP not shown)
F11 200 OK atlanta.com proxy -> Alice SIP/2.0 200 OK Via: SIP/2.0/UDP pc33.atlanta.com;branch=z9hG4bKnashds8 ;received=192.0.2.1 To: Bob <sip:bob@biloxi.com>;tag=a6c85cf From: Alice <sip:alice@atlanta.com>;tag=1928301774 Call-ID: a84b4c76e66710 CSeq: 314159 INVITE Contact: <sip:bob@192.0.2.4> Content-Type: application/sdp Content-Length: 131 (Bob's SDP not shown) F12 ACK Alice -> Bob ACK sip:bob@192.0.2.4 SIP/2.0 Via: SIP/2.0/UDP pc33.atlanta.com;branch=z9hG4bKnashds9 Max-Forwards: 70 To: Bob <sip:bob@biloxi.com>;tag=a6c85cf From: Alice <sip:alice@atlanta.com>;tag=1928301774 Call-ID: a84b4c76e66710 CSeq: 314159 ACK Content-Length: 0 The media session between Alice and Bob is now established. Bob hangs up first. Note that Bob's SIP phone maintains its own CSeq numbering space, which, in this example, begins with 231. Since Bob is making the request, the To and From URIs and tags have been swapped. F13 BYE Bob -> Alice BYE sip:alice@pc33.atlanta.com SIP/2.0 Via: SIP/2.0/UDP 192.0.2.4;branch=z9hG4bKnashds10 Max-Forwards: 70 From: Bob <sip:bob@biloxi.com>;tag=a6c85cf To: Alice <sip:alice@atlanta.com>;tag=1928301774 Call-ID: a84b4c76e66710 CSeq: 231 BYE Content-Length: 0
F14 200 OK Alice -> Bob SIP/2.0 200 OK Via: SIP/2.0/UDP 192.0.2.4;branch=z9hG4bKnashds10 From: Bob <sip:bob@biloxi.com>;tag=a6c85cf To: Alice <sip:alice@atlanta.com>;tag=1928301774 Call-ID: a84b4c76e66710 CSeq: 231 BYE Content-Length: 0 The SIP Call Flows document [40] contains further examples of SIP messages.25 Augmented BNF for the SIP Protocol
All of the mechanisms specified in this document are described in both prose and an augmented Backus-Naur Form (BNF) defined in RFC 2234 [10]. Section 6.1 of RFC 2234 defines a set of core rules that are used by this specification, and not repeated here. Implementers need to be familiar with the notation and content of RFC 2234 in order to understand this specification. Certain basic rules are in uppercase, such as SP, LWS, HTAB, CRLF, DIGIT, ALPHA, etc. Angle brackets are used within definitions to clarify the use of rule names. The use of square brackets is redundant syntactically. It is used as a semantic hint that the specific parameter is optional to use.25.1 Basic Rules
The following rules are used throughout this specification to describe basic parsing constructs. The US-ASCII coded character set is defined by ANSI X3.4-1986. alphanum = ALPHA / DIGIT
Several rules are incorporated from RFC 2396 [5] but are updated to make them compliant with RFC 2234 [10]. These include: reserved = ";" / "/" / "?" / ":" / "@" / "&" / "=" / "+" / "$" / "," unreserved = alphanum / mark mark = "-" / "_" / "." / "!" / "~" / "*" / "'" / "(" / ")" escaped = "%" HEXDIG HEXDIG SIP header field values can be folded onto multiple lines if the continuation line begins with a space or horizontal tab. All linear white space, including folding, has the same semantics as SP. A recipient MAY replace any linear white space with a single SP before interpreting the field value or forwarding the message downstream. This is intended to behave exactly as HTTP/1.1 as described in RFC 2616 [8]. The SWS construct is used when linear white space is optional, generally between tokens and separators. LWS = [*WSP CRLF] 1*WSP ; linear whitespace SWS = [LWS] ; sep whitespace To separate the header name from the rest of value, a colon is used, which, by the above rule, allows whitespace before, but no line break, and whitespace after, including a linebreak. The HCOLON defines this construct. HCOLON = *( SP / HTAB ) ":" SWS The TEXT-UTF8 rule is only used for descriptive field contents and values that are not intended to be interpreted by the message parser. Words of *TEXT-UTF8 contain characters from the UTF-8 charset (RFC 2279 [7]). The TEXT-UTF8-TRIM rule is used for descriptive field contents that are n t quoted strings, where leading and trailing LWS is not meaningful. In this regard, SIP differs from HTTP, which uses the ISO 8859-1 character set. TEXT-UTF8-TRIM = 1*TEXT-UTF8char *(*LWS TEXT-UTF8char) TEXT-UTF8char = %x21-7E / UTF8-NONASCII UTF8-NONASCII = %xC0-DF 1UTF8-CONT / %xE0-EF 2UTF8-CONT / %xF0-F7 3UTF8-CONT / %xF8-Fb 4UTF8-CONT / %xFC-FD 5UTF8-CONT UTF8-CONT = %x80-BF
A CRLF is allowed in the definition of TEXT-UTF8-TRIM only as part of
a header field continuation. It is expected that the folding LWS
will be replaced with a single SP before interpretation of the TEXT-
UTF8-TRIM value.
Hexadecimal numeric characters are used in several protocol elements.
Some elements (authentication) force hex alphas to be lower case.
LHEX = DIGIT / %x61-66 ;lowercase a-f
Many SIP header field values consist of words separated by LWS or
special characters. Unless otherwise stated, tokens are case-
insensitive. These special characters MUST be in a quoted string to
be used within a parameter value. The word construct is used in
Call-ID to allow most separators to be used.
token = 1*(alphanum / "-" / "." / "!" / "%" / "*"
/ "_" / "+" / "`" / "'" / "~" )
separators = "(" / ")" / "<" / ">" / "@" /
"," / ";" / ":" / "\" / DQUOTE /
"/" / "[" / "]" / "?" / "=" /
"{" / "}" / SP / HTAB
word = 1*(alphanum / "-" / "." / "!" / "%" / "*" /
"_" / "+" / "`" / "'" / "~" /
"(" / ")" / "<" / ">" /
":" / "\" / DQUOTE /
"/" / "[" / "]" / "?" /
"{" / "}" )
When tokens are used or separators are used between elements,
whitespace is often allowed before or after these characters:
STAR = SWS "*" SWS ; asterisk
SLASH = SWS "/" SWS ; slash
EQUAL = SWS "=" SWS ; equal
LPAREN = SWS "(" SWS ; left parenthesis
RPAREN = SWS ")" SWS ; right parenthesis
RAQUOT = ">" SWS ; right angle quote
LAQUOT = SWS "<"; left angle quote
COMMA = SWS "," SWS ; comma
SEMI = SWS ";" SWS ; semicolon
COLON = SWS ":" SWS ; colon
LDQUOT = SWS DQUOTE; open double quotation mark
RDQUOT = DQUOTE SWS ; close double quotation mark
Comments can be included in some SIP header fields by surrounding the
comment text with parentheses. Comments are only allowed in fields
containing "comment" as part of their field value definition. In all
other fields, parentheses are considered part of the field value.
comment = LPAREN *(ctext / quoted-pair / comment) RPAREN
ctext = %x21-27 / %x2A-5B / %x5D-7E / UTF8-NONASCII
/ LWS
ctext includes all chars except left and right parens and backslash.
A string of text is parsed as a single word if it is quoted using
double-quote marks. In quoted strings, quotation marks (") and
backslashes (\) need to be escaped.
quoted-string = SWS DQUOTE *(qdtext / quoted-pair ) DQUOTE
qdtext = LWS / %x21 / %x23-5B / %x5D-7E
/ UTF8-NONASCII
The backslash character ("\") MAY be used as a single-character
quoting mechanism only within quoted-string and comment constructs.
Unlike HTTP/1.1, the characters CR and LF cannot be escaped by this
mechanism to avoid conflict with line folding and header separation.
quoted-pair = "\" (%x00-09 / %x0B-0C
/ %x0E-7F)
SIP-URI = "sip:" [ userinfo ] hostport
uri-parameters [ headers ]
SIPS-URI = "sips:" [ userinfo ] hostport
uri-parameters [ headers ]
userinfo = ( user / telephone-subscriber ) [ ":" password ] "@"
user = 1*( unreserved / escaped / user-unreserved )
user-unreserved = "&" / "=" / "+" / "$" / "," / ";" / "?" / "/"
password = *( unreserved / escaped /
"&" / "=" / "+" / "$" / "," )
hostport = host [ ":" port ]
host = hostname / IPv4address / IPv6reference
hostname = *( domainlabel "." ) toplabel [ "." ]
domainlabel = alphanum
/ alphanum *( alphanum / "-" ) alphanum
toplabel = ALPHA / ALPHA *( alphanum / "-" ) alphanum
IPv4address = 1*3DIGIT "." 1*3DIGIT "." 1*3DIGIT "." 1*3DIGIT IPv6reference = "[" IPv6address "]" IPv6address = hexpart [ ":" IPv4address ] hexpart = hexseq / hexseq "::" [ hexseq ] / "::" [ hexseq ] hexseq = hex4 *( ":" hex4) hex4 = 1*4HEXDIG port = 1*DIGIT The BNF for telephone-subscriber can be found in RFC 2806 [9]. Note, however, that any characters allowed there that are not allowed in the user part of the SIP URI MUST be escaped. uri-parameters = *( ";" uri-parameter) uri-parameter = transport-param / user-param / method-param / ttl-param / maddr-param / lr-param / other-param transport-param = "transport=" ( "udp" / "tcp" / "sctp" / "tls" / other-transport) other-transport = token user-param = "user=" ( "phone" / "ip" / other-user) other-user = token method-param = "method=" Method ttl-param = "ttl=" ttl maddr-param = "maddr=" host lr-param = "lr" other-param = pname [ "=" pvalue ] pname = 1*paramchar pvalue = 1*paramchar paramchar = param-unreserved / unreserved / escaped param-unreserved = "[" / "]" / "/" / ":" / "&" / "+" / "$" headers = "?" header *( "&" header ) header = hname "=" hvalue hname = 1*( hnv-unreserved / unreserved / escaped ) hvalue = *( hnv-unreserved / unreserved / escaped ) hnv-unreserved = "[" / "]" / "/" / "?" / ":" / "+" / "$" SIP-message = Request / Response Request = Request-Line *( message-header ) CRLF [ message-body ] Request-Line = Method SP Request-URI SP SIP-Version CRLF Request-URI = SIP-URI / SIPS-URI / absoluteURI absoluteURI = scheme ":" ( hier-part / opaque-part ) hier-part = ( net-path / abs-path ) [ "?" query ] net-path = "//" authority [ abs-path ] abs-path = "/" path-segments
opaque-part = uric-no-slash *uric
uric = reserved / unreserved / escaped
uric-no-slash = unreserved / escaped / ";" / "?" / ":" / "@"
/ "&" / "=" / "+" / "$" / ","
path-segments = segment *( "/" segment )
segment = *pchar *( ";" param )
param = *pchar
pchar = unreserved / escaped /
":" / "@" / "&" / "=" / "+" / "$" / ","
scheme = ALPHA *( ALPHA / DIGIT / "+" / "-" / "." )
authority = srvr / reg-name
srvr = [ [ userinfo "@" ] hostport ]
reg-name = 1*( unreserved / escaped / "$" / ","
/ ";" / ":" / "@" / "&" / "=" / "+" )
query = *uric
SIP-Version = "SIP" "/" 1*DIGIT "." 1*DIGIT
message-header = (Accept
/ Accept-Encoding
/ Accept-Language
/ Alert-Info
/ Allow
/ Authentication-Info
/ Authorization
/ Call-ID
/ Call-Info
/ Contact
/ Content-Disposition
/ Content-Encoding
/ Content-Language
/ Content-Length
/ Content-Type
/ CSeq
/ Date
/ Error-Info
/ Expires
/ From
/ In-Reply-To
/ Max-Forwards
/ MIME-Version
/ Min-Expires
/ Organization
/ Priority
/ Proxy-Authenticate
/ Proxy-Authorization
/ Proxy-Require
/ Record-Route
/ Reply-To
/ Require
/ Retry-After
/ Route
/ Server
/ Subject
/ Supported
/ Timestamp
/ To
/ Unsupported
/ User-Agent
/ Via
/ Warning
/ WWW-Authenticate
/ extension-header) CRLF
INVITEm = %x49.4E.56.49.54.45 ; INVITE in caps
ACKm = %x41.43.4B ; ACK in caps
OPTIONSm = %x4F.50.54.49.4F.4E.53 ; OPTIONS in caps
BYEm = %x42.59.45 ; BYE in caps
CANCELm = %x43.41.4E.43.45.4C ; CANCEL in caps
REGISTERm = %x52.45.47.49.53.54.45.52 ; REGISTER in caps
Method = INVITEm / ACKm / OPTIONSm / BYEm
/ CANCELm / REGISTERm
/ extension-method
extension-method = token
Response = Status-Line
*( message-header )
CRLF
[ message-body ]
Status-Line = SIP-Version SP Status-Code SP Reason-Phrase CRLF
Status-Code = Informational
/ Redirection
/ Success
/ Client-Error
/ Server-Error
/ Global-Failure
/ extension-code
extension-code = 3DIGIT
Reason-Phrase = *(reserved / unreserved / escaped
/ UTF8-NONASCII / UTF8-CONT / SP / HTAB)
Informational = "100" ; Trying
/ "180" ; Ringing
/ "181" ; Call Is Being Forwarded
/ "182" ; Queued
/ "183" ; Session Progress
Success = "200" ; OK
Redirection = "300" ; Multiple Choices
/ "301" ; Moved Permanently
/ "302" ; Moved Temporarily
/ "305" ; Use Proxy
/ "380" ; Alternative Service
Client-Error = "400" ; Bad Request
/ "401" ; Unauthorized
/ "402" ; Payment Required
/ "403" ; Forbidden
/ "404" ; Not Found
/ "405" ; Method Not Allowed
/ "406" ; Not Acceptable
/ "407" ; Proxy Authentication Required
/ "408" ; Request Timeout
/ "410" ; Gone
/ "413" ; Request Entity Too Large
/ "414" ; Request-URI Too Large
/ "415" ; Unsupported Media Type
/ "416" ; Unsupported URI Scheme
/ "420" ; Bad Extension
/ "421" ; Extension Required
/ "423" ; Interval Too Brief
/ "480" ; Temporarily not available
/ "481" ; Call Leg/Transaction Does Not Exist
/ "482" ; Loop Detected
/ "483" ; Too Many Hops
/ "484" ; Address Incomplete
/ "485" ; Ambiguous
/ "486" ; Busy Here
/ "487" ; Request Terminated
/ "488" ; Not Acceptable Here
/ "491" ; Request Pending
/ "493" ; Undecipherable
Server-Error = "500" ; Internal Server Error
/ "501" ; Not Implemented
/ "502" ; Bad Gateway
/ "503" ; Service Unavailable
/ "504" ; Server Time-out
/ "505" ; SIP Version not supported
/ "513" ; Message Too Large
Global-Failure = "600" ; Busy Everywhere
/ "603" ; Decline
/ "604" ; Does not exist anywhere
/ "606" ; Not Acceptable
Accept = "Accept" HCOLON
[ accept-range *(COMMA accept-range) ]
accept-range = media-range *(SEMI accept-param)
media-range = ( "*/*"
/ ( m-type SLASH "*" )
/ ( m-type SLASH m-subtype )
) *( SEMI m-parameter )
accept-param = ("q" EQUAL qvalue) / generic-param
qvalue = ( "0" [ "." 0*3DIGIT ] )
/ ( "1" [ "." 0*3("0") ] )
generic-param = token [ EQUAL gen-value ]
gen-value = token / host / quoted-string
Accept-Encoding = "Accept-Encoding" HCOLON
[ encoding *(COMMA encoding) ]
encoding = codings *(SEMI accept-param)
codings = content-coding / "*"
content-coding = token
Accept-Language = "Accept-Language" HCOLON
[ language *(COMMA language) ]
language = language-range *(SEMI accept-param)
language-range = ( ( 1*8ALPHA *( "-" 1*8ALPHA ) ) / "*" )
Alert-Info = "Alert-Info" HCOLON alert-param *(COMMA alert-param)
alert-param = LAQUOT absoluteURI RAQUOT *( SEMI generic-param )
Allow = "Allow" HCOLON [Method *(COMMA Method)]
Authorization = "Authorization" HCOLON credentials
credentials = ("Digest" LWS digest-response)
/ other-response
digest-response = dig-resp *(COMMA dig-resp)
dig-resp = username / realm / nonce / digest-uri
/ dresponse / algorithm / cnonce
/ opaque / message-qop
/ nonce-count / auth-param
username = "username" EQUAL username-value
username-value = quoted-string
digest-uri = "uri" EQUAL LDQUOT digest-uri-value RDQUOT
digest-uri-value = rquest-uri ; Equal to request-uri as specified
by HTTP/1.1
message-qop = "qop" EQUAL qop-value
cnonce = "cnonce" EQUAL cnonce-value
cnonce-value = nonce-value
nonce-count = "nc" EQUAL nc-value
nc-value = 8LHEX
dresponse = "response" EQUAL request-digest
request-digest = LDQUOT 32LHEX RDQUOT
auth-param = auth-param-name EQUAL
( token / quoted-string )
auth-param-name = token
other-response = auth-scheme LWS auth-param
*(COMMA auth-param)
auth-scheme = token
Authentication-Info = "Authentication-Info" HCOLON ainfo
*(COMMA ainfo)
ainfo = nextnonce / message-qop
/ response-auth / cnonce
/ nonce-count
nextnonce = "nextnonce" EQUAL nonce-value
response-auth = "rspauth" EQUAL response-digest
response-digest = LDQUOT *LHEX RDQUOT
Call-ID = ( "Call-ID" / "i" ) HCOLON callid
callid = word [ "@" word ]
Call-Info = "Call-Info" HCOLON info *(COMMA info)
info = LAQUOT absoluteURI RAQUOT *( SEMI info-param)
info-param = ( "purpose" EQUAL ( "icon" / "info"
/ "card" / token ) ) / generic-param
Contact = ("Contact" / "m" ) HCOLON
( STAR / (contact-param *(COMMA contact-param)))
contact-param = (name-addr / addr-spec) *(SEMI contact-params)
name-addr = [ display-name ] LAQUOT addr-spec RAQUOT
addr-spec = SIP-URI / SIPS-URI / absoluteURI
display-name = *(token LWS)/ quoted-string
contact-params = c-p-q / c-p-expires
/ contact-extension
c-p-q = "q" EQUAL qvalue
c-p-expires = "expires" EQUAL delta-seconds
contact-extension = generic-param
delta-seconds = 1*DIGIT
Content-Disposition = "Content-Disposition" HCOLON
disp-type *( SEMI disp-param )
disp-type = "render" / "session" / "icon" / "alert"
/ disp-extension-token
disp-param = handling-param / generic-param
handling-param = "handling" EQUAL
( "optional" / "required"
/ other-handling )
other-handling = token
disp-extension-token = token
Content-Encoding = ( "Content-Encoding" / "e" ) HCOLON
content-coding *(COMMA content-coding)
Content-Language = "Content-Language" HCOLON
language-tag *(COMMA language-tag)
language-tag = primary-tag *( "-" subtag )
primary-tag = 1*8ALPHA
subtag = 1*8ALPHA
Content-Length = ( "Content-Length" / "l" ) HCOLON 1*DIGIT
Content-Type = ( "Content-Type" / "c" ) HCOLON media-type
media-type = m-type SLASH m-subtype *(SEMI m-parameter)
m-type = discrete-type / composite-type
discrete-type = "text" / "image" / "audio" / "video"
/ "application" / extension-token
composite-type = "message" / "multipart" / extension-token
extension-token = ietf-token / x-token
ietf-token = token
x-token = "x-" token
m-subtype = extension-token / iana-token
iana-token = token
m-parameter = m-attribute EQUAL m-value
m-attribute = token
m-value = token / quoted-string
CSeq = "CSeq" HCOLON 1*DIGIT LWS Method
Date = "Date" HCOLON SIP-date
SIP-date = rfc1123-date
rfc1123-date = wkday "," SP date1 SP time SP "GMT"
date1 = 2DIGIT SP month SP 4DIGIT
; day month year (e.g., 02 Jun 1982)
time = 2DIGIT ":" 2DIGIT ":" 2DIGIT
; 00:00:00 - 23:59:59
wkday = "Mon" / "Tue" / "Wed"
/ "Thu" / "Fri" / "Sat" / "Sun"
month = "Jan" / "Feb" / "Mar" / "Apr"
/ "May" / "Jun" / "Jul" / "Aug"
/ "Sep" / "Oct" / "Nov" / "Dec"
Error-Info = "Error-Info" HCOLON error-uri *(COMMA error-uri)
error-uri = LAQUOT absoluteURI RAQUOT *( SEMI generic-param ) Expires = "Expires" HCOLON delta-seconds From = ( "From" / "f" ) HCOLON from-spec from-spec = ( name-addr / addr-spec ) *( SEMI from-param ) from-param = tag-param / generic-param tag-param = "tag" EQUAL token In-Reply-To = "In-Reply-To" HCOLON callid *(COMMA callid) Max-Forwards = "Max-Forwards" HCOLON 1*DIGIT MIME-Version = "MIME-Version" HCOLON 1*DIGIT "." 1*DIGIT Min-Expires = "Min-Expires" HCOLON delta-seconds Organization = "Organization" HCOLON [TEXT-UTF8-TRIM] Priority = "Priority" HCOLON priority-value priority-value = "emergency" / "urgent" / "normal" / "non-urgent" / other-priority other-priority = token Proxy-Authenticate = "Proxy-Authenticate" HCOLON challenge challenge = ("Digest" LWS digest-cln *(COMMA digest-cln)) / other-challenge other-challenge = auth-scheme LWS auth-param *(COMMA auth-param) digest-cln = realm / domain / nonce / opaque / stale / algorithm / qop-options / auth-param realm = "realm" EQUAL realm-value realm-value = quoted-string domain = "domain" EQUAL LDQUOT URI *( 1*SP URI ) RDQUOT URI = absoluteURI / abs-path nonce = "nonce" EQUAL nonce-value nonce-value = quoted-string opaque = "opaque" EQUAL quoted-string stale = "stale" EQUAL ( "true" / "false" ) algorithm = "algorithm" EQUAL ( "MD5" / "MD5-sess" / token ) qop-options = "qop" EQUAL LDQUOT qop-value *("," qop-value) RDQUOT qop-value = "auth" / "auth-int" / token Proxy-Authorization = "Proxy-Authorization" HCOLON credentials
Proxy-Require = "Proxy-Require" HCOLON option-tag *(COMMA option-tag) option-tag = token Record-Route = "Record-Route" HCOLON rec-route *(COMMA rec-route) rec-route = name-addr *( SEMI rr-param ) rr-param = generic-param Reply-To = "Reply-To" HCOLON rplyto-spec rplyto-spec = ( name-addr / addr-spec ) *( SEMI rplyto-param ) rplyto-param = generic-param Require = "Require" HCOLON option-tag *(COMMA option-tag) Retry-After = "Retry-After" HCOLON delta-seconds [ comment ] *( SEMI retry-param ) retry-param = ("duration" EQUAL delta-seconds) / generic-param Route = "Route" HCOLON route-param *(COMMA route-param) route-param = name-addr *( SEMI rr-param ) Server = "Server" HCOLON server-val *(LWS server-val) server-val = product / comment product = token [SLASH product-version] product-version = token Subject = ( "Subject" / "s" ) HCOLON [TEXT-UTF8-TRIM] Supported = ( "Supported" / "k" ) HCOLON [option-tag *(COMMA option-tag)] Timestamp = "Timestamp" HCOLON 1*(DIGIT) [ "." *(DIGIT) ] [ LWS delay ] delay = *(DIGIT) [ "." *(DIGIT) ] To = ( "To" / "t" ) HCOLON ( name-addr / addr-spec ) *( SEMI to-param ) to-param = tag-param / generic-param Unsupported = "Unsupported" HCOLON option-tag *(COMMA option-tag) User-Agent = "User-Agent" HCOLON server-val *(LWS server-val)
Via = ( "Via" / "v" ) HCOLON via-parm *(COMMA via-parm) via-parm = sent-protocol LWS sent-by *( SEMI via-params ) via-params = via-ttl / via-maddr / via-received / via-branch / via-extension via-ttl = "ttl" EQUAL ttl via-maddr = "maddr" EQUAL host via-received = "received" EQUAL (IPv4address / IPv6address) via-branch = "branch" EQUAL token via-extension = generic-param sent-protocol = protocol-name SLASH protocol-version SLASH transport protocol-name = "SIP" / token protocol-version = token transport = "UDP" / "TCP" / "TLS" / "SCTP" / other-transport sent-by = host [ COLON port ] ttl = 1*3DIGIT ; 0 to 255 Warning = "Warning" HCOLON warning-value *(COMMA warning-value) warning-value = warn-code SP warn-agent SP warn-text warn-code = 3DIGIT warn-agent = hostport / pseudonym ; the name or pseudonym of the server adding ; the Warning header, for use in debugging warn-text = quoted-string pseudonym = token WWW-Authenticate = "WWW-Authenticate" HCOLON challenge extension-header = header-name HCOLON header-value header-name = token header-value = *(TEXT-UTF8char / UTF8-CONT / LWS) message-body = *OCTET
(page 232 continued on part 12)