Yealink SIP-T48G Administrator's Manual page 715

Acoustic Echo Cancellation (AEC) is used to reduce acoustic echo from a voice call to
provide natural full-duplex communication patterns. It also increases the capacity
achieved through silence suppression by preventing echo from traveling across a
network. IP phones employ advanced AEC for hands-free operation. AEC is not
normally required for calls via the handset. In certain situation, where echo is
experienced by the remote party, AEC may be used to reduce/avoid echo when the
user uses the handset.
Note
Utilizing acoustic echo cancellation will introduce a small delay increase into audio path
which might cause a lower voice quality.
Procedure
AEC can be configured using the configuration files or locally.
Configuration File
Local
Details of the Configuration Parameter:
Parameter
voice.echo_cancellation
Description:
Enables or disables the AEC (Acoustic Echo Canceller) feature on the IP phone.
0-Disabled
1-Enabled
Web User Interface:
Settings->Voice->Echo Cancellation->ECHO
<y0000000000xx>.cfg
Web User Interface
Permitted Values
0 or 1
Configuring Audio Features
Configure AEC.
Parameter:
voice.echo_cancellation
Configure AEC.
Navigate to:
http://<phoneIPAddress>/
servlet?p=settings-voice&
q=load
Default
1
695