AudioCodes Mediant 4000 SBC, User Manual

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CHAPTER 15 Media
Mediant 4000 SBC | User's Manual
The device also supports acoustic echo cancellation for SBC calls. These echoes are composed of
undesirable acoustical reflections (non-linear) of the received signal (i.e., from the speaker) which
find their way from multiple reflections such as walls and windows into the transmitted signal (i.e.,
microphone). Therefore, the party at the far end hears his / her echo. The device removes these
echoes and sends only the near-end’s desired speech signal to the network (i.e., to the far-end
party). The echo is composed of a linear part and a nonlinear part. However, in the Acoustic Echo
Canceler, a substantial part of the echo is non-linear echo. To support this feature, the Forced
Transcoding feature must be enabled so that the device uses DSPs.
The following procedure describes how to configure echo cancellation through the Web interface:
➢
To configure echo cancellation:
1. Configure line echo cancellation:
a. Open the Voice Settings page ( Setup menu > Signaling & Media tab > Media folder >
Voice Settings ).
b. From the 'Echo Canceller' drop-down list ( EnableEchoCanceller ), select Enable .
2. Enable acoustic echo cancellation for SBC calls:
a. Open the Voice Settings page (Setup menu > Signaling & Media tab > Media folder >
Voice Settings).
b. Under the Network Echo Suppressor group:
c. In the Voice Settings page, configure the following parameters:
◆
'Network Echo Suppressor Enable' (AcousticEchoSuppressorSupport) - enables the
network Acoustic Echo Suppressor
◆
'Echo Canceller Type' (EchoCancellerType) - defines the echo canceller type
◆
'Attenuation Intensity' (AcousticEchoSuppAttenuationIntensity) - defines the acoustic
echo suppressor signals identified as echo attenuation intensity
◆
'Max ERL Threshold' (AcousticEchoSuppMaxERLThreshold) - defines the acoustic
echo suppressor maximum ratio between signal level and returned echo from the
phone
◆
'Min Reference Delay' (AcousticEchoSuppMinRefDelayx10ms) - defines the acoustic
echo suppressor minimum reference delay
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