[Asterisk-Users] Upgrading 1.0.9 to 1.2 beta

[Tom Rymes]

On Nov 13, 2005, at 8:36 AM, Chris Bagnall wrote:

> Hello all,
>
> I'm contemplating upgrading a client's asterisk system from 1.0.9  
> to 1.2
> beta to take advantage of some of the new echo cancellers in the later
> zaptel packages. Problem is, I'll be doing it without physical  
> access to the
> box and without being able to personally test the new echo  
> cancellation for
> them, so I'll be relying on information they provide me with.
>
> Their setup involves a Rev. I TDM400 card with 3 FXO modules  
> connected to
> standard BT analogue lines. They've been complaining about echo for  
> some
> time, despite the multitude of options I've tried in zapata.conf to  
> limit
> the echo problem.
>
> Here are the current zapata.conf settings:
> echocancel=yes
> echocancelwhenbridged=yes
> echotraining=800
> rxgain=12.0
> txgain=8.0
>
> (rxgain and txgain calculated by running ztmonitor on a number of  
> different
> calls over a period of a few days, aiming to keep the levels in the  
> middle)

Chris,

Before you upgrade to 1.2 and potentially break a lot of things, have  
you followed the instructions available at <http://www.voip-info.org/ 
wiki/view/Asterisk+zapata+gain+adjustment> to adjust the rxgain and  
txgain? I can't say without testing the machine, but those levels  
look extremely high to me , and might be exacerbating, if not causing  
the echo problem. Try to adjust the gains quantitatively using  
milliwatt lines first before you go the upgrade route.

Tom