RFC 3389 RTP Payload for Comfort

This document describes a RTP [1] payload format for transporting comfort noise. The payload format is based on Appendix II of ITU-T Recommendation G.711 [8] which defines a comfort noise payload format (or bit-stream) for ITU-T G.711 [2] use in packet-based multimedia communication systems. The payload format is generic and may also be used with other audio codecs without built-in Discontinuous Transmission (DTX) capability such as ITU-T Recommendations G.726 [3], G.727 [4], G.728 [5], and G.722 [6]. The payload format provides a minimum interoperability specification for communication of comfort noise parameters. The comfort noise analysis and synthesis as well as the Voice Activity Detection (VAD) and DTX algorithms are unspecified and left implementation-specific.