AudioCodes Mediant 2000 User Manual page 369

SIP User's Manual
Parameter
Web: Echo Canceler
EMS: Echo Canceller Enable
[EnableEchoCanceller]
Web: Max Echo Canceller Length
[MaxEchoCancellerLength]
EMS: Echo Canceller Hybrid Loss
[ECHybridLoss]
[ECNLPMode]
Version 5.8

[2] Enable without Adaptation = A single silence packet is
sent during a silence period (applicable only to G.729).
Note: If the selected coder is G.729, the value of the 'annexb'
parameter of the fmtp attribute in the SDP is determined by
the following rules:

If EnableSilenceCompression is 0: 'annexb=no'.

If EnableSilenceCompression is 1: 'annexb=yes'.

If EnableSilenceCompression is 2 and IsCiscoSCEMode is
0: 'annexb=yes'.

If EnableSilenceCompression is 2 and IsCiscoSCEMode is
1: 'annexb=no'.
Determines whether echo cancellation is enabled and
therefore, echo from voice calls is removed.

[0] Off = Echo Canceler is disabled.

[1] On = Echo Canceler is enabled (default).
Note: This parameter is used to maintain backward
compatibility.
Determines the maximum Echo Canceler Length (in msec),
which is the maximum echo path delay (tail length) for which
the echo canceller is designed to operate:

[0] Default = based on various internal device settings to
attain maximum channel capacity (default)

[11] 64 msec

[22] 128 msec
Notes:

For this parameter to take effect, a device reset is required.

Using 128 msec reduces the channel capacity to 200
channels.

It is unnecessary to configure the parameter
EchoCancellerLength, as it automatically acquires its value
from this parameter.
Sets the four wire to two wire worst-case Hybrid loss, the ratio
between the signal level sent to the hybrid and the echo level
returning from the hybrid.

[0] = 6 dB (default)

[1] = N/A

[2] = 0 dB

[3] = 3 dB
Defines the echo cancellation Non-Linear Processing (NLP)
mode.

[0] = NLP adapts according to echo changes (default).

[1] = Disables NLP.
369
6. Configuration Parameters Reference
Description
October 2009