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Step Command Remarks
3. Configure the interval
between off-hook and dialing
the first digit.
timer first-dial seconds
The default is 10 seconds.
This command applies only to FXO
and FXS interfaces.
4. Configure the maximum
interval for dialing the next
digit.
timer dial-interval seconds The default is 10 seconds.
5. Configure the maximum
duration for playing ringback
tones.
timer ring-back seconds The default is 60 seconds.
6. Configure the dial delay time.
delay start-dial seconds
The default is 1 second.
This command applies to only FXO
and FXS interfaces.
7. Configure the hookflash time
range.
timer hookflash-detect
hookflash-range
By default, the hookflash time
range is 50 to 180 milliseconds;
that is, if an on-hook condition lasts
for a period that falls within the
hookflash time range, it is
considered a hookflash.
This command applies to only FXS
interfaces.
8. Configure the maximum
duration the terminating
device waits for the first digit.
timer wait-digit { seconds |
infinity }
The default is 5 seconds.
This command applies to only E&M
interfaces.
Configuring the comfortable noise function
You can configure this feature to generate comfortable background noise to replace the silent gaps
during a conversation.
To configure the comfortable noise 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 comfortable noise
function.
cng-on By default, this function is enabled.
Configuring echo cancellation
An echo is the audible leak-through of your own voice into your own receive path. When the voice of a
user leaks into the receive path, it is an echo. The echo cancellation function can alleviate the echo
problem.
The time when an echo occurs and the size of the echo are relatively fixed. As shown in Figure 8, ther
e
is a voice signal at time 0, and an echo occurs after about 40 milliseconds (ms). To cancel this echo, set
