Adding a Telephone Field to the SDP Session Structure

The sdp_add_phone() function adds the PHONE (p=) SDP field to the session structure that is specified by the value of the session parameter (sdp_session_t) using the phone parameter.

Return Values: The sdp_add_phone() function returns 0 when the function completes successfully. When mandatory parameters are not present, the function returns EINVAL. When memory allocation fails, the function returns ENOMEM. The value of errno does not change in the event of an error.