The IESG has approved the following document: - 'The Session Initiation Protocol (SIP) Conference Bridge Transcoding Model ' <draft-ietf-sipping-transc-conf-03.txt> as a Proposed Standard This document is the product of the Session Initiation Proposal Investigation Working Group. The IESG contact persons are Jon Peterson and Cullen Jennings. A URL of this Internet-Draft is: http://www.ietf.org/internet-drafts/draft-ietf-sipping-transc-conf-03.txt Technical Summary This 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. The Framework for Transcoding with SIP describes how two SIP UAs (User Agents) can discover imcompatibilities that prevent them from establishing a session (e.g., lack of support for a common codec or for a common media type). When such incompatibilities are found, the UAs need to invoke transcoding services to successfully establish the session. The transcoding framework introduces two models to invoke transcoding services: the 3pcc (third-party call control) model and the conference bridge model. This document specifies the conference bridge model. In the conference bridge model for transcoding invocation, a transcoding server that provides a particular transcoding service (e.g., speech-to-text) behaves as a B2BUA (Back-to-Back User Agent) between both UAs and is identified by a URI. The UAs do not exchange any traffic (signalling or media) directly between them Working Group Summary This document was developed in the SIPPING working group, in large part to address requirements raised by related work dealing with conferencing for the hearing-impaired. The document was initially presented as an individual contribution, was adopted by the WG, and went through several iterations as a working group document before being formally reviewed in a working-group last call and developing a consensus on publication. Protocol Quality This document was reviewed for the IESG by Jon Peterson. There are believed to be several implementations of this approach either in-use or demonstrated at interoperability events. _______________________________________________ IETF-Announce@ietf.org https://www1.ietf.org/mailman/listinfo/ietf-announce
