1226 SIP Messages

 

Both types of messages consist of a start-line, one or more header fields, an

   empty line indicating the end of the header fields, and an optional

   message-body.

 

         generic-message  =  start-line

                             *message-header

                             CRLF

                             [ message-body ]

         start-line       =  Request-Line / Status-Line

 

   The start-line, each message-header line, and the empty line MUST be

   terminated by a carriage-return line-feed sequence (CRLF).  Note that

   the empty line MUST be present even if the message-body is not.空行结束

7.1 Requests

   SIP requests are distinguished by having a Request-Line for a start-

   line.  A Request-Line contains a method name, a Request-URI, and the

   protocol version separated by a single space (SP) character.

 

   The Request-Line ends with CRLF.  No CR or LF are allowed except in

   the end-of-line CRLF sequence.  No linear whitespace (LWS) is allowed

   in any of the elements.

 

         Request-Line  =  Method SP Request-URI SP SIP-Version CRLF

      Method: This specification defines six methods: REGISTER for

           registering contact information, INVITE, ACK, and CANCEL for

           setting up sessions, BYE for terminating sessions, and

           OPTIONS for querying servers about their capabilities.  SIP

           extensions, documented in standards track RFCs, may define

           additional methods.

 

      Request-URI: The Request-URI is a SIP or SIPS URI as described in

           Section 19.1 or a general URI (RFC 2396 [5]).  It indicates

           the user or service to which this request is being addressed.

           The Request-URI MUST NOT contain unescaped spaces or control

           characters and MUST NOT be enclosed in "<>".