asterisk users - Jun 2006 - TDM400P bad echo problem, tried lots of things

I have a bad echo problem on my TDM400P with one FXO module installed.

I have tried a few things, such as:

* setting rxgain and txgain to 0
* setting echocancelwhenbridged to no / yes
* settting echocancel to 64 / no / yes
* setting echocanceltraining to 800 / no / yes
* MG2 echo cancellation
* MARK2 echo cancellation
* KB1 echo cancellation
* AGGRESSIVE_SUPPRESSOR option of MARK2

Each time restarting Asterisk, then opening the Zap channel, and then
speaking...only to hear my self played back almost instantly. 

None of these options changed the echo for me, it always sounded the
same -- except for the AGGRESSIVE_SUPPRESSOR option, in which every time
I spoke it made the other end a very low volume, so much that I couldn't
hear the other end (ie: not useful).

I don't have this problem with pure IP calls, it's only with my TDM400P
and FXO that I have this echo problem. This means my headset and IP
phones are fine (of course).

So, what else can I try? :-)

Any ideas why this is so consistent and persistent? Maybe it's something
to do with my phone cable or something of that nature (hmm?)?

Any input appreciated.

Thanks,
Carey O'Shea.

Try these settings in zapata.conf:

echocancel=64
echotraining=800
echocancelwhenbridged=yes
rxgain=3.2
txgain=-3.2

with default KB1 echo canceller in zconfig.h

This setup was working fairly okay for me for about a year or so.

Also, notice that at the first seconds of the call you may hear some 
echo, but then it disappears. I just trained myself to ignore this first 
seconds echo. =)

Please give the list information regarding the phone that you use with 
*. This maybe a cheap phone problem, as well.

Andrei (MPI)

Carey O'Shea wrote:
> I have a bad echo problem on my TDM400P with one FXO module installed.
>
> I have tried a few things, such as:
>
> * setting rxgain and txgain to 0
> * setting echocancelwhenbridged to no / yes
> * settting echocancel to 64 / no / yes
> * setting echocanceltraining to 800 / no / yes
> * MG2 echo cancellation
> * MARK2 echo cancellation
> * KB1 echo cancellation
> * AGGRESSIVE_SUPPRESSOR option of MARK2
>
> Each time restarting Asterisk, then opening the Zap channel, and then
> speaking...only to hear my self played back almost instantly. 
>
> None of these options changed the echo for me, it always sounded the
> same -- except for the AGGRESSIVE_SUPPRESSOR option, in which every time
> I spoke it made the other end a very low volume, so much that I
couldn't
> hear the other end (ie: not useful).
>
> I don't have this problem with pure IP calls, it's only with my
TDM400P
> and FXO that I have this echo problem. This means my headset and IP
> phones are fine (of course).
>
> So, what else can I try? :-)
>
> Any ideas why this is so consistent and persistent? Maybe it's
something
> to do with my phone cable or something of that nature (hmm?)?
>
> Any input appreciated.
>
> Thanks,
> Carey O'Shea.
>
>
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>
>

I was having this issue - though a DSL filter was the root cause.
Here is what I did to erradicate echo:
Upgrade to newest zaptel/libpri.
cd  /usr/src/
mv zaptel zaptel.old
mv libpri libpri.old
svn checkout http://svn.digium.com/svn/zaptel/trunk zaptel
svn checkout http://svn.digium.com/svn/libpri/trunk libpri

cd zaptel
|# cd zaptel
# make clean; make install; make config
# cd ../libpri
# make clean; make install
|
cat /etc/fxotune.conf
cd zaptel
amportal stop
./fxotune -d -b <fxoport ie 1,2,3,or 4>
./fxotune -d -b <fxoport> -w 1004
./fxotune -i 5 -t 1
./fxotune -d -b <fxoport> -w 1004
./fxotune -i 5
./fxotune -s
amportal start
cat /etc/fxotune.conf

This assumes you're using asterisk management portal or freepbx.

Good luck.

JD
Carey O'Shea wrote:
> I have a bad echo problem on my TDM400P with one FXO module installed.
>
> I have tried a few things, such as:
>
> * setting rxgain and txgain to 0
> * setting echocancelwhenbridged to no / yes
> * settting echocancel to 64 / no / yes
> * setting echocanceltraining to 800 / no / yes
> * MG2 echo cancellation
> * MARK2 echo cancellation
> * KB1 echo cancellation
> * AGGRESSIVE_SUPPRESSOR option of MARK2
>
> Each time restarting Asterisk, then opening the Zap channel, and then
> speaking...only to hear my self played back almost instantly. 
>
> None of these options changed the echo for me, it always sounded the
> same -- except for the AGGRESSIVE_SUPPRESSOR option, in which every time
> I spoke it made the other end a very low volume, so much that I
couldn't
> hear the other end (ie: not useful).
>
> I don't have this problem with pure IP calls, it's only with my
TDM400P
> and FXO that I have this echo problem. This means my headset and IP
> phones are fine (of course).
>
> So, what else can I try? :-)
>
> Any ideas why this is so consistent and persistent? Maybe it's
something
> to do with my phone cable or something of that nature (hmm?)?
>
> Any input appreciated.
>
> Thanks,
> Carey O'Shea.
>
>
> _______________________________________________
> --Bandwidth and Colocation provided by Easynews.com --
>
> Asterisk-Users mailing list
> To UNSUBSCRIBE or update options visit:
>    http://lists.digium.com/mailman/listinfo/asterisk-users
>   
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Try fxotune.  That's the first thing you should have used.

Matthew Fredrickson

On Jun 20, 2006, at 11:55 AM, Carey O'Shea wrote:
> I have a bad echo problem on my TDM400P with one FXO module installed.
>
> I have tried a few things, such as:
>
> * setting rxgain and txgain to 0
> * setting echocancelwhenbridged to no / yes
> * settting echocancel to 64 / no / yes
> * setting echocanceltraining to 800 / no / yes
> * MG2 echo cancellation
> * MARK2 echo cancellation
> * KB1 echo cancellation
> * AGGRESSIVE_SUPPRESSOR option of MARK2
>
> Each time restarting Asterisk, then opening the Zap channel, and then
> speaking...only to hear my self played back almost instantly.
>
> None of these options changed the echo for me, it always sounded the
> same -- except for the AGGRESSIVE_SUPPRESSOR option, in which every 
> time
> I spoke it made the other end a very low volume, so much that I 
> couldn't
> hear the other end (ie: not useful).
>
> I don't have this problem with pure IP calls, it's only with my
TDM400P
> and FXO that I have this echo problem. This means my headset and IP
> phones are fine (of course).
>
> So, what else can I try? :-)
>
> Any ideas why this is so consistent and persistent? Maybe it's 
> something
> to do with my phone cable or something of that nature (hmm?)?
>
> Any input appreciated.
>
> Thanks,
> Carey O'Shea.
>
>
> _______________________________________________
> --Bandwidth and Colocation provided by Easynews.com --
>
> Asterisk-Users mailing list
> To UNSUBSCRIBE or update options visit:
>    http://lists.digium.com/mailman/listinfo/asterisk-users