Conveying Tones in the Session Initiation Protocol (SIP)
Cisco Systems
One of the major applications of the Session Initiation Protocol (SIP) is in Internet telephony. In this context it is often useful or convenient for a SIP entity to request another SIP User Agent generate some type of tone, without generating this tone as part of a session. This document describes how SIP can be used without modification to carry such tones and explores issues relating to their use. Finally this document defines a new MIME type which is useful for conveying computer generated tones.