Yealink SIP-T38G

Configuring Audio Features
179
Comfort Noise Generation (CNG) is used to generate background noise for voice
communications during periods of silence that occur during the conversation. It is part of
the silence suppression or VAD handling for VoIP technology. CNG, in conjunction with
VAD algorithms, quickly determines when periods of silence occur and inserts artificial
noise until voice activity resumes. The insertion of artificial noise gives the illusion of a
constant transmission stream, so that background sound is consistent throughout the
call and the listener does not think the line has released. The purpose of VAD and CNG
is to maintain an acceptable perceived QoS while simultaneously keeping transmission
costs and bandwidth usage as low as possible.
Procedure
CNG can be configured using the configuration files or locally.
Configuration File
<y0000000000xx>.cfg
Configure the CNG feature.
For more information, refer to
Comfort Noise Generation on
page 303.
Local
Web User Interface
Configure the CNG feature.
Navigate to:
http://<phoneIPAddress>/cgi-bi
n/cgiServer.exx?page=Phone-V
oice.htm
To configure CNG via web user interface:
1. Click on Phone->Voice.
2. Select the desired value from the pull-down list of CNG.
3. Click Confirm to accept the change.