Yealink SIP-T54S Administrator's Manual page 909

Procedure
CNG can be configured using the following methods.
Central Provisioning
(Configuration File)
Web User Interface
Details of the Configuration Parameter:
Parameter
voice.cng
Description:
Enables or disables the CNG (Comfortable Noise Generation) feature on the IP phone.
0-Disabled
1-Enabled
Web User Interface:
Settings->Voice->Echo Cancellation->CNG
Phone User Interface:
None
To configure CNG via web user interface:
Click on Settings->Voice.
1.
Select the desired value from the pull-down list of CNG.
2.
<y0000000000xx>.cfg
Permitted Values
0 or 1
Configuring Audio Features
Configure CNG.
Parameter:
voice.cng
Configure CNG.
Navigate to:
http://<phoneIPAddress>/servlet?
p=settings-voice&q=load
Default
1
883