A Real-Time Transport Protocol (RTP) Header Extension for Client-to- Mixer Audio Level Indication

Document Type Replaced Internet-Draft (individual)
Authors Jonathan Lennox  , Emil Ivov  , Enrico Marocco 
Last updated 2011-03-03 (latest revision 2010-07-11)
Replaced by RFC 6464
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This Internet-Draft is no longer active. A copy of the expired Internet-Draft can be found at


This document defines a mechanism by which packets of Real-Time Transport Protocol (RTP) audio streams can indicate, in an RTP header extension, the audio level of the audio sample carried in the RTP packet. In large conferences, this can reduce the load on an audio mixer or other middlebox which wants to forward only a few of the loudest audio streams, without requiring it to decode and measure every stream that is received.


Jonathan Lennox (jonathan@vidyo.com)
Emil Ivov (emcho@sip-communicator.org)
Enrico Marocco (enrico.marocco@telecomitalia.it)

(Note: The e-mail addresses provided for the authors of this Internet-Draft may no longer be valid.)