20
the echo cancellation delay (the time between when an interface sends out a signal and when to the
interface receives an echo) to 33 ms and the echo cancellation coverage to 16 ms.
Figure 8 Echo
Configuring the echo cancellation function
Step Command Remarks
1. Enter system view.
system-view N/A
2. Enter voice interface view.
subscriber-line line-number N/A
3. Enable the echo cancellation
function.
echo-canceler enable
By default, this function is enabled.
4. Configure the echo
cancellation delay.
echo-canceler delay milliseconds The default is 0 milliseconds.
5. Configure the echo
cancellation coverage.
echo-canceler tail-length
milliseconds
The default is 128 milliseconds.
Adjusting echo cancellation parameters
Table 1 describes how to adjust echo cancellation parameters for different symptoms.
Table 1 Adjusting echo cancellation parameters
S
m
tom Parameters ad
usted
Effect
A user hears echoes or loud
background noises from the peer
when speaking.
Speed up the convergence of
comfortable noise amplitudes.
Too fast convergence might make
noises uncomfortable.
There are loud environment noises.
Increase the maximum amplitude
of comfortable noises.
Too large amplitude might make
noises uncomfortable.
A user hears echoes when
speaking.
Enlarge the mixture proportion
control factor of comfortable
noises.
Too high a control factor leads to
audio discontinuity.
There are echoes when both
parties speak at the same time.
Enlarge the two-way judgment
threshold.
Too high a judgment threshold
slows down the convergence of the
filter factor.
To adjust echo cancellation parameters:
Step Command Remarks
1. Enter system view.
system-view N/A
