RTP Payload Format for a 64 kbit/s Transparent Call
realtime transport protocol
This document describes how to carry 64 kbit/s channel data transparently in RTP packets, using a pseudo-codec called "Clearmode". It also serves as registration for a related MIME type called "audio/clearmode". "Clearmode" is a basic feature of VoIP Media Gateways. [STANDARDS-TRACK]