[Asterisk-Users] Echo on Zaptel FXO :(

[Phil Quinney]

Comments inline:

On 8 Jan 2005, at 22:02, Ian Chilton wrote:

> Hi All,
>
> I've got an MD3200 modem which is working as a Zaptel FXO interface for
> Asterisk (X100P clone I believe). It seems to work, but on incoming or
> outgoing calls I can hear the other party ok but when I speak, I hear
> my voice echo back at me (quite quietly but it's distracting!) on
> everything I say. The other party doesn't seem to hear the echo - they
> just say I sound a bit quiet.
>
> Someone suggested I play with the rxgain and txgain but this didn't  
> seem
> to help. Is there anything I can do? - or is it a problem with my fxo
> card or zaptel cards in general?
>
> I'm running Asterisk 1.0.2-2 on Debain Linux (with zaptel 1.0.0-2) and
> i've got the modem connected to an NTL phone line in the UK. Here is my
> config's:
>
> /etc/zaptel.conf:
>
Change  fxsls to fxsks for the UK

> fxsls=1
> loadzone=uk
> defaultzone=uk
>
>
> /etc/zapata.conf:
>
> [channels]
>   context=incoming_pstn

Also change fxsls here to fxsks

>   signalling=fxs_ls
>   usecallerid=yes
>   echocancel=yes
>   echocancelwhenbridged=yes
>   echotraining=yes
>   rxgain=0.0
>   txgain=0.0

I find rxgain=2.0, txgain=2.0 to be the sweet spots for my UK setup.  
The aim is to get the monitor bars in ztmonitor to be at about half way  
when talking.

>   channel => 1
>
--Snip--

Please also note that the X100/1P cards are not suitable for use in the  
UK. They work on the American systems where the impedance is different  
to the UK. Google for more info.

You may find that asterisk reports the Zap channel as being in a  
strange ringing state: Add busydetect=no callprogress=no to solve this  
(I found that I could not get the devices to answer the line without  
these set: either on my BT line or NTL line.

Hope this helps,

Phil.

------------------------------------------------------------------------ 
--------------------------
Phil Quinney
IT Consultant - Any-Ideas