----- Original Message -----
Sent: Monday, January 23, 2006 12:13
AM
Subject: Re: [Asterisk-Users] Reducing
echo on FXS port
Hello Giovanni and
everybody,
Thanks a lot for your
suggestion.
Unfortunately, that does not help. With
READ_SIZE=16, I got vibrating voice on the speaker phone. With READ_SIZE=80,
the voice came back to normal and the echo is more reduced but still
noticeable. I finally changed it back to 160 as it seems to affect a lot of
things in chan_zap.
I am sorry that I didn't properly explain
the setup I have. I think this issue happens because I use wireless handset.
Here is my actual setup:
--------------- out
------------
| |
<--- | |
Wireless
handset <--> Base phone <--> FXS (TDM400P) <--> | ZAP
Channel | | Asterisk |
(Mic
muted)
| |
---> |
|
--------------- in
------------
^
Monitor()
The delay between the original voice
going out from asterisk to the phone, and its echo coming back to asterisk is
about 104 ms, assuming that Monitor() application wrote both files at exactly
the same time. How did I find that? I loaded the "in" and "out" files created
by Monitor() application into Audacity (audacity.sourceforge.net). I could not
find any other method to find this delay. Does anyone know a better and more
accurate method?
When I did the same thing using X-Lite
with below setup:
--------------- out
------------
| |
<--- | |
PC
(X-Lite) <--> | SIP Channel | | Asterisk
|
(Mic muted)
| |
---> |
|
--------------- in
------------
^
Monitor()
There is no sound at all on the "in" file
created by Monitor() application, indicating that there is no echo at all as
the microphone on X-Lite was muted.
Since the echo on FXS is consistent,
there must be a way to eliminate it. The question is how? I think it can not
be done only by changing the configuration parameters related to echo,
especially with this huge delay.
Do you have any other
suggestions?
Cheers,
Anto