asterisk users - Jun 2004 - tdm (and x100p?) echo - fix is coming!

Good news!

FYI, worked with Mark this afternoon to test changes needed to reduce
or eliminate echo involving pstn calls on the new tdm fxo card (bug
#1902).

Three simple source code changes (testing-only at this point) resulted 
in zero detectable echo on all incoming and outgoing tdm pstn calls,
even in the first second or two. I've not noticed any unusual side 
effects at all. Since the changes were only to chan_zap.c, I'll have 
to guess it will improve the historic x100p echo issues as well, and 
probably other zap channels also.

The changes were associated with the echo cancel routines, but as a
non-programmer, I'm not sure what these changes really do (other than
the end result).

If these changes prove to be successfull, then Mark is going to make
them configurable options somewhere. Got'a love it.

Rich

Beside of problem of CallerID not working in several countries, what
specially I still don't know if it's a X100P's limitation or Zap
driver
limitation, the major problem with this devices is no doubt the echo.
If you guys can solve this with tdms and x100ps, it's gonna be a big
step.


On Wed, 23 Jun 2004, Rich Adamson wrote:
> Good news!
>
> FYI, worked with Mark this afternoon to test changes needed to reduce
> or eliminate echo involving pstn calls on the new tdm fxo card (bug
> #1902).
>
> Three simple source code changes (testing-only at this point) resulted
> in zero detectable echo on all incoming and outgoing tdm pstn calls,
> even in the first second or two. I've not noticed any unusual side
> effects at all. Since the changes were only to chan_zap.c, I'll have
> to guess it will improve the historic x100p echo issues as well, and
> probably other zap channels also.
>
> The changes were associated with the echo cancel routines, but as a
> non-programmer, I'm not sure what these changes really do (other than
> the end result).
>
> If these changes prove to be successfull, then Mark is going to make
> them configurable options somewhere. Got'a love it.
>
> Rich
>
>
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> > Per the doc in the configs samples, you have to implement
> echotraining=800 (instead of
> > "yes") to take advantage of the new code from yesterday.
> 
> Was this in the new samples from the CVS?
Yes. I did a full Head checkout this morning, and the comments
were included in the /usr/src/asterisk/configs/zapata.conf.samples
(or something like that).

Rich