RTP Silence Suppression ?
Endpoints sending audio as an RTP stream are not required to send packets during silent periods. The capability to stop sending RTP packets during silent periods is known as “Silence Suppression” or VAD (Voice Activity Detection). Whether to use Silence Suppression is usually a configuration option on endpoints. When processing a stream of RTP packets, here is what RFC 3389 has to say about detecting Silence Suppression: Echo Cancellation Echo cancellation is the process of removing echo from a voice communication in order to improve the voice call quality. Echo cancellation is often needed because speech compression techniques and packet processing delays generate echo. There are 2 types of echo: acoustic echo and hybrid echo. Echo cancellation not only improves quality but it also reduces bandwidth consumption because of its silence suppression technique.
