AudioCodes Mediant 3000, User Manual

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Version 6.6 167 Mediant 3000
User's Manual 13. Media
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 procedure below describes how to configure echo cancellation using the Web
interface:

To configure echo cancellation using the Web interface:
1. Configure line echo cancellation:
a. Open the Voice Settings page ( Configuration tab > VoIP menu > Media
submenu > Voice Settings ).
Figure 13-4: Voice Settings Page
b. Set the 'Echo Canceller' field ( EnableEchoCanceller ) to Enable .
2. Enable acoustic echo cancellation for SBC calls:
a. 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
♦
'Max Reference Delay' (AcousticEchoSuppMaxRefDelayx10ms) - defines
the acoustic echo suppressor maximum reference delay
b. Open the IP Profile Settings page (Configuration tab > VoIP menu > Coders and
Profiles submenu > IP Profile Settings), and set the 'Echo Canceller' field to
Acoustic.
c. Enable the Forced Transcoding feature (using the TranscodingMode parameter)
to allow the device to use DSP channels, which are required for acoustic echo
cancellation.
Note: The following additional echo cancellation parameters are configurable only
through the ini file:
•
ECHybridLoss - defines the four-wire to two-wire worst-case Hybrid loss
•
ECNLPMode - defines the echo cancellation Non-Linear Processing
(NLP) mode
•
EchoCancellerAggressiveNLP - enables Aggressive NLP at the first 0.5
second of the call