Silence Suppression allows a Cisco IP Phone to detect the absence of audio and does not transmit packets over the network. The sound quality may be slightly degraded but the connection may also use less bandwidth. Silence Suppression is disabled by default.

A software device used to stop the transmission of silent voice traffic over the Internet in order to save bandwidth.

In a telephone conversation, only about 50% of the full duplex connection is used at any given time. This is generally because only one person talks while the other person listens. In addition, voice packets are not sent during interword pauses and natural pauses in the conversation, reducing the required bandwidth by another 10%. Silence suppression frees this 60% of bandwidth on the full duplex link for other voice or data transmissions.