Sending Messages

An application sends a SIP message by using the sip_sendmsg() function with the connection object and any message specific flags. The message formatting layer adds a Content-Length header and a line that contains only a Carriage Return/Line Feed (CRLF) character to the message and delivers the packet to the next layer. The message formatting layer copies all of the SIP message's headers and contents into a contiguous buffer before delivering the message to the application's send function. The connection manager provides the send function.