Re: [asterisk-users] modem through Zaptel/Digium?

On Jan 17, 2008 1:28 PM, Jeremy Mann <jmann@txhmg.com> wrote:

Is it bridging the Zap channels?  We have asterisk doing FXO-FXS modem calls working fine, the key is making sure the channels are bridging and EC is NOT turning on.  If you have anything preventing that the modem calls won't work.

-----Original Message-----
From: asterisk-users-bounces@lists.digium.com [mailto: asterisk-users-bounces@lists.digium.com] On Behalf Of Dave Fullerton
Sent: Thursday, January 17, 2008 12:05 PM
To: Asterisk Users Mailing List - Non-Commercial Discussion
Subject: Re: [asterisk-users] modem through Zaptel/Digium?

Greg Woods wrote:
> This is just a low priority curiosity question because I have a usable
> workaround.
>
> I have  Digium card that uses the Zaptel driver (can't get to my home
> machine right now to get the exact model, but it probably doesn't
> matter). It's a card with one POTS line and three extension hookups. I'm
> using Asterisk 1.4 and Zaptel 1.4.7 .
>
> One of the extension ports is connected to a modem on another computer.
> This is a FAX modem that works well; I have * programmed to detect
> incoming faxes and route them to this modem, and it works seamlessly. I
> can also send outbound faxes with no problem.
>
> The curiosity is that this modem does not work for dialup unless I
> bypass the * server and connect it directly to the wallplate, then it
> works fine. I don't see why it would be able to detect carrier and
> negotiate with a fax machine through * and Zaptel, but not with a dialup
> server.
>
> --Greg

I think asterisk has the ability to detect fax tones and disable echo
cancellation for those calls. I don't know if that is the case with a
regular modem call. I'd check to make sure that echo cancellation is
disabled on the extension the modem is plugged into. The only other idea
is to try connecting at a lower speed (I would think this would happen
automatically though).

-Dave

Try setting the modem to 9600 baud.  It will probably work.

Thanks,
Steve Totaro