http://www.rfc-editor.org/rfc/rfc5370.txt
RFC 5370: The Session Initiation Protocol (SIP) Conference Bridge Transcoding Model, G. Camarillo2008-10-01T23:00:00-00:00This document describes how to invoke transcoding services using the conference bridge model. This way of invocation meets the requirements for SIP regarding transcoding services invocation to support deaf, hard of hearing, and speech-impaired individuals. [STANDARDS-TRACK]