[Asterisk-Users] TDM400P bad echo problem, tried lots of things

[Carey O'Shea]

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.