VAD - Explained in simple terms

WHAT IS THIS VAD ?

In Voice over IP (VOIP), voice activation detection (VAD) is a software application that allows a data network carrying voice traffic over the Internet to detect the absence of audio and conserve bandwidth by preventing the transmission of "silent packets" over the network. Most conversations include about 50% silence; VAD (also called "silence suppression") can be enabled to monitor signals for voice activity so that when silence is detected for a specified amount of time, the application informs the Packet Voice Protocol and prevents the encoder output from being transported across the network.

Voice activation detection can also be used to forward idle noise characteristics (sometimes called ambient or comfort noise) to a remote IP telephone or gateway. The universal standard for digitized voice, 64 Kbps, is a constant bit rate whether the speaker is actively speaking, is pausing between thoughts, or is totally silent. Without idle noise giving the illusion of a constant transmission stream during silence suppression, the listener would be likely to think the line had gone dead.

This feature is fully available on the Huawei SBC SE2300, SE2600 & SE2900 as No Media-Stream detection &  media-bypass features. 

*** No media stream detection is a function which enables the SE2600 to send a BYE message to the UE and the core server after detecting that no media stream is available in one direction or both directions of a session for a period which is longer than the maximum allowable period. The core server tears down the session immediately after receiving the BYE message, improving the accuracy of subscriber charging.