[asterisk-users] Certain fax types cause problems

[Steve Davies]

Feedback on my testing here.

On 7/10/06, Doug Lytle <support at drdos.info> wrote:
> Steve Davies wrote:
> > Hi,
> >
> > I was wondering whether anyone has any input into the reliability of
> > faxing (over a PRI) using spandsp and rxfax.
> >
> > 99% of times this is a reliable combination - we use it almost
> > exclusively, but there seem to be certain fax devices which have
> > problems talking to us. Most notably fax modems, and a couple of HP
> > multi-function devices.
> >
> SpanDSP does very little or no error checking, when an error is
> encountered, it will fail.

Hmmm... I just switched to iaxmodem on a loopback interface as
documented, and tried both Hylafax and efax. Both seemed to drop out
on any fax larger than 3 pages.

When I switched back to app_rxfax, I could receive any length of fax
once again. It is also easier to integrate Asterisk and rxfax as
asterisk can control where the fax is saved, and what is done to it
based on the call that occurred (eg. CLID and dialled number)

Also, Hylafax is BIG, especially by the time ghostscript and its
prerequisites are installed...

> > Any pointers on how to diagnose or improve this would be appreciated.
> >
> Install HylaFAX and iaxmodem on your Asterisk box.
>

iaxmodem does use an updated version of spandsp - perhaps that is the
source of my problems in this particular case. What I would LOVE is a
version of app_rxfax that works with spandsp-0.0.3 and asterisk 1.0.x
so I could pin this down further - Perhaps I'll have to backport the
"test" version of rxfax myself.

Thanks for the pointers.
Steve