[Asterisk-Users] spandsp, rxfax, TDM400/zaptel, missed frames, any help?

[Ben Fried]

I'm doing this from memory, so there may be errors. I'm using a at h 2.2
as a base, though I'd added a bunch of RPMs for things like fonts
along the way.

Install hylafax  - if you a at h, there's a CentOS RPM for hylafax you
can use. I believe I had to install some (obvious) dependencies, but
they were straightforward and easy to do with yum; then I had to make
some symlinks for the ghostscript fontss and one or two other things;
the hylafax setup tells you where it looks for stuff and if it found
it or not.

Building iaxmodem is a tiny bit  tricky; it uses a different version
of spandsp from what a at h's build of rxfax and txfax uses, which causes
asterisk to crash if it had loaded rxfax and txfax, and it also and
overwrites the install location of what came with a at h. I had to remove
the dso's for rxfax and txfax after installing iaxmodem and restart
asterisk, and all was fine.

I made some trivial changes to the default iaxmodem configuration,
which I don't think were significant (told it to use ulaw, but it
seems to negotiate to the slinear codec  anyway).

Run iaxmodem on the same machine running Asterisk. I had to change the
iax.conf [general] stanza to bandwidth=high and tos=reliability, and
to add allow=slinear

In the a at h AMP console, add an iax extension. It has to have a numeric
extension identifier. Make that be the "peername" filed of the
iaxmodem config. In the AMP console, specify that extension 300 (or
whatever extension # you made iaxmodem) is the handler for faxes.

Run faxgetty on ttyIAX with the configuration that came with iaxmodem.

At this point, you can test to see if things are working or not. Send
yourself some faxes.  /var/spool/hylafax/log has a separate log file
for each inbound or outbound fax; you can tail them and the asterisk
logs to see what's going on. I get a lot of HDLC errors but they all
seem benign. If everything works, the inbound faxes will be delivered
as PDF to whoever the recipient of FaxMaster mail. sendfax sends
faxes; it also leaves logs in /var/spool/hylafax/log.

Once you're sure everything's working, make sure everything will come
back on startup.

I added the following two lines to a at h's /etc/rc3.d/S99local:
/usr/local/bin/iaxmodem ttyIAX > /var/log/iaxmodem.stdout 2>
/var/log/iaxmodem.stderr &
/usr/sbin/faxgetty ttyIAX &

Using inittab seems like a more elegant approach: it will respawn
processes that exit unexpectedly and this won't, but it wasn't clear
to me that I could have lines in inittab that I knew were executed
after S99local.

IMHO, iaxmodem and hylafax should be standard parts of a at h, and are
far preferable to rxfax and txfax. Aside from the virtue of working
where the asterisk builtins don't, hylafax is a far more mature,
complete, and feature-rich fax engine, with a strong community around
it.

Good luck.

Ben

On 1/17/06, Philip Edelbrock <phil at netroedge.com> wrote:
>
>
> Ben Fried wrote:
> > Just to be clear, I have inbound and outbound faxes working with my
> > TDM400, by going the iaxmodem and hylafax route. No need for a
> > separate modem or an x100p card.
> >
> > Be
> >
>
> Ah, that's interesting.  Can you provide some details on how you set it up?
>
>
> Phil
>