Topic: SIP fax detection in SAIL

[karld]

Is it possible to do incoming fax detection on voip trunks with sail?  I would really like to start moving our systems away from
trixbox, but lack of NVFax (so far as I can tell) is causing me some grief.


Any hope?

[kb-ohnemus]

In short: You can use hylafax and iaxmodem (softmodem for asterisk) and then define as many fax-extensions as you like.

[SARK devs]

SAIL will detect FAX on analogue lines.  It suffers froim the same problems as asterisk generally does in this role but it does kind-of work.  DDI FAX over PRI works pretty good.  We normally ship the DDI directly to a hardfax via an SPA2102.

I know nothing of hylafax.  Never tried it, so anyone who does have experience please feel free to pitch in.  Isn't there another version/fork of hyla which is supposed to be easier to install?

Also if someone wants to get it running with SAIL and needs any hacking done then we'll help if we can.  If there's one thing we can always do here, its fix perfectly good code to the point where it breaks. 


Best

S
 

[karld]

Thanks for the replies!

What would be ideal is something like FreePBX does.  It uses an asterisk module called nvfax to detect an incoming fax on a sip or iax trunk then sends it to an email address as a pdf.  I believe that asterisk can be recompiled to include app_nv_* but that's about as far as my knowledge goes.  What's great about this is that we can use one DID for voice and fax and not have anything print out.

Can something like this be hacked into SAIL?  Maybe a custom app to run incoming calls against nvfax?

So fair SAIL/SME has been far more reliable for us than trixbox, and this is the only feature keeping us from converting en mass.

[SARK devs]

We've had a look at this.

Here's what we know.

Hylafax is pretty well understood in SME but only at the hardware FAX modem level. Nobody considered multiple FAX DiDs because it was done before anyone had the idea to shove asterisk onto the SME platform.  However, the modifications needed to support DiD FAX are not particularly complex.

IAXmodem is needed to form the bridge between Asterisk and Hylafax.  We downloaded this and compiled it on one of our VM SME dev images this afternoon without problems.

This means that ordinary FAX DiDs can be accomodated without change to the SAIL AGI or generators.  For now, a simple custom app can do the IAX dial to Hyla thru IAXmodem and be driven directly from the inbound DiD trunk.

If you want dual-purpose DiDs (that can switch between FAX and Voice), then we will have to compile the app_nv stuff and either create a little rpm for it or  provide it as a binary. 

Now, we don't have hard FAX here at Selintra because we use hosted FAX-to-Email through our PSTN Carrier.  If you wish us to do this integration (and it sounds like a useful thing to do), then we will need some volunteers to help us test.  Preferably you will already have some experience of running Hyla.

S

[Franco]

Count me in for the tests!
I'm already a Hylafax user and never really tried this approach.
I have a FXS module on SAIL with the external modem connected to it. Hylafax sends me the fax via email.
We send the fax signal to this line when it comes via PSTN, and for the remote locations I buy a DiD number (US, Italy and Brazil) just for the faxes (less than $5 a month) and direct to this extension.

[domainwizard]

happy to help out on the tests as well,

i have 80+ virtual faxes running on hyla and iaxmodem, on a single use server which works consistantly as long as it it connected to asterix via a lan as any dropped packets, or latency makes it uber flakey.
by way of experience it would seem that if one wishes to recieve faxes, a dedicated box is probably a preferrable approach. when it works it works very well,  i have found with hyla it is best not to delete an iax modem as it seems to scramble all the accounts. an existing account can be reassigned to another inbound did without problems though.

detection of "accidental" faxes sent to dids assigned to sail would be a nice add on, and those calls routed to a dedicated fax box.

[SARK devs]

OK guys,

We've put up a new release of sail (-622) on the download site...

www.selintra.co.uk/sail/sail-2.2.1/

Among other things it contains the first bit of the FAX stuff you've asked for.  It will automatically install IAXmodem and add a getty for it (ttyIAX).   We've also done the necessary legwork to have smeserver automatically start IAXmodem at each reboot. 

We've also added a new pseudo SIP device called iaxmodem.  This means you can create an extension in SAIL and it will generate the necessary IAX.conf entries for IAXmodem.   This way, you can pipe DDI faxes straight to the IAXmodem extension. 

The Hylafax install we used was the smeserver-hylafax rpm.  It does all the work to properly install Hyla into the SME environment.  If you intend to run Hyla on a  separate machine then obviously you don't need this step.

The only other thing we did was to add a ttyIAX0 device to hyla. 

We haven't run any faxes through the setup but we can dial the IAXmodem extension and get FAX tones back from Hyla which suggests that it is ready to go.

Please let us know how you get on and also what additional tailoring you need.

This is obviously very new and a bit rough around the edges at the moment but rather than try to deliver the whole thing we thought a stepwise approach might be better.  If this is OK then we can look at adding NVfaxdetect and the rest.

Kind Regards

S