Getting Fax Detection to Work

For a couple of days now, I have been trying to get fax detection working. I’ve been through a vast number of threads (on this site as well as around the Web) just trying to find some definitive information to help me get fax detection to work. But, I really have not found much of anything that has brought any sort of success to my current configuration.

According to a few of the threads I read through, fax detection is supposed to work “straight out of the box”. But it has not been so for myself. Since NVFax is greyed out, the only real option left for us is to use dahdi, or so I figure since we do not have a sip trunk to use. Something I found was that faxdetect=incoming is to be included in chan_dahdi.conf (thought the hint indicates “Dahdi.conf”.

The question is, what could I be missing? I figure that there must be some solution. Personally, I blame my own noobness. Anyone have any thoughts or can someone direct me to the answer? It would be much appreciated.



Pls provide more info about your setup. Are you running the FreePBX distro? How can you not have a SIP trunk?

Typically you would open the “Fax Configuration module”, fill in the information, setup an inbound route with SIP fax detection and point it to a fax enabled extension.

The forum does contain more info.

Thanks for responding. We are running the FreePBX distro, yes. How it is that we don’t have a SIP trunk has largely to do with the fact that we are located in a more rural area where SIP is not really in use, not widely known about, or offered by local telcos. That leaves us relying on analog lines with our phone systems for our customers. Yes, it’s sad. We have been relying on another solution that is far from perfect which involves some external Sipura units. Of course, incoming faxes are more successful than outbound.

I have scanned the forums thoroughly, and I think I’ve gotten the information out of them that I can. I have configured the Fax Configuration Module, and set the inbound route to detect fax. But, it still does not work. I could really use a tested and workable solution for this if such a thing exists.

I have come across two or three unanswered posts that seek a similar solution. I must say that this does not leave me with a great amount of confidence that there actually is a sleeker solution than what we’ve got. But, any ideas would be appreciated. Thanks.

We only use VoIP and inbound fax works great for us but if you are all Analog then I can’t really help. However if you are using ulaw (alaw) in your Asterisk PBX I would guess you shouldn’t have any problems with incoming faxes.

Outgoing faxes usually don’t work on SIP lines but on analog lines I guess it might work.

Faxdetect=incoming is ok in chan_dahdi.conf
Make sure udptl.conf exists

Maybe someone else can chip in?

Were you ever able to get inbound fax reception working? I’ve gone through all the FreePBX fax setup, and while the logfiles indicate that the system is detecting incoming faxes, it never receives one. I’ve been through multiple forums and searched all over the place, but apparently nobody has been able to get this working properly. I’m beginning to wonder if the “free fax” feature is intentionally non-functional, to create enough frustration that people will pay for a support call.

OK, apparently one must slog through the convoluted process of obtaining a license for “Free Fax for Asterisk” as described here:

After enduring that craziness, AsteriskNOW actually received and emailed a fax. Wonder of wonders.

If any developer types are paying attention, can I suggest a couple of things? First, the AsteriskNOW/FreePBX interface offers exactly zero indication that this licensing process is necessary. Nothing useful in the logs or anywhere else I could find. Maybe I missed something in the documentation, but for crying out loud…how about a useful log message if inbound fax detection is enabled but there’s no licensed fax module available to handle faxes? Second, omigosh PLEASE come up with an easier method of licensing and installation. I’m a CLI gearhead, but nobody else around here is. That’s the reason I snagged AsteriskNOW–because it incorporated this great UI that (mostly) eliminated any need to muck around on the command line. If it were just the free version of Fax for Asterisk that required the insanity, well OK, it’s free, whattaya want. But apparently even the “real” version requires the same insanity. Yowza.

Freepbx fax detection works right out of the box of you have the distro. No need to set up Digium ‘free fax’. However if you are using AsteriskNow then you are ranting in the wrong forum as that is a completely different system. It just happens to use the same GUI.

If the “FreePBX” that’s installed by the AsteriskNOW distro isn’t “real” FreePBX, then what is it? As I understand it, FreePBX is a frontend to Asterisk, and both the FreePBX distro and AsteriskNOW install both Asterisk and FreePBX. I say “as I understand it,” because I have yet to stumble across a thread, either in these forums or Asterisk’s, that actually explains the differences. They “just happen to use the same GUI” because FreePBX is the GUI. At least, that’s how I understand it. I’d love for you to shed some light on my ignorance.

What I do know is that when I try to enable inbound faxing in the “FreePBX” frontend (cuz that’s what it says it is), it doesn’t work. Not only that, but it doesn’t give anything close to meaningful errors in the logfiles. Not only that, but neither the FreePBX forums nor the AsteriskNOW forums appear to have any meaningful “how to” on getting inbound faxing to work. I realize it’s free software, no support, yada yada, but to give a pat answer like “it works right out of the box” is almost comical. No, it doesn’t work right out of the box.

Asterisk now doesn’t work out of the box with FreePBX because it is not setup correctly and they don’t update the FreePBX dependencies.

In fact the person that started Asterisknow within Digium works for Schmooze now.

There are many different add ons for Asterisk to support faxing. FreePBX supports many of them.

The FreePBX Distro, a distribution of Asterisk and FreePBX, fully integrated including the many back end dependencies and current does work out of the box.

Thanks, SkykingOH, that’s helpful. I wish I’d known this before I spent so much time fighting with AsteriskNOW. Is there anything that AsteriskNOW does better than FreePBX? I realize I’m on the FreePBX forums here, which might be just a little biased, but I’m wondering why Asterisk doesn’t just point to the FreePBX distro instead of pushing AsteriskNOW with a FreePBX “skin” on it. I figure the reasons are probably part political and part technical.

Political, commercial no so technical.

I have to ask because we spend so much time on it, how did you miss our distro and not include in the evaluation process?

I couldn’t find a good comparison of AsteriskNOW & FreePBX anywhere, needed something fast, and made an assumption that the Asterisk folks would probably have the best Asterisk distro. Reasonable assumption, I think, but apparently wrong.

Yes, we hate the confusion too as everyone winds up back here and frustrated. Without good Linux knowledge it’s difficult to plug all the parts together.

It really was a hard decision to even make a distro at first.

Well, I posted my issues to the AsteriskNOW and FreePBX forums at the same time, and haven’t heard a peep from anyone in the other place. So the issue appears to be settled: FreePBX is the Asterisk distro that actually works, the FreePBX community is helpful, and the FreePBX team is more committed to making a good product better. Now I just have to find the time to make the switch…

Hi all,

I know this thread is a bit old but I have found on this forum and implemented some information regarding getting fax working inbound yet to test outbound as who has a fax machine these days anyway!!!. ( this is the link
many thanks to gwinton)

See below:

In advance SIP settings.
T38 Pass-Through = Yes
Now create a file in /etc/asterisk. Call it udptl.conf.
Ensure the below is in it.
T38FaxUdpEC = t38UDPFEC
T38FaxUdpEC = t38UDPRedundancy
T38FaxMaxDatagram = 400
udptlfecentries = 3
udptlfecspan = 3

I haven’t been able to get the fax detect working as of yet but incoming faxes are working as I am using a alog line for incoming faxes and a SIP trunk for everything else (my SIP provider doesn’t support T38)On the Alog FXO incoming I just set the forward straight to the Fax enabled extension (in my case 8998)which then goes straight to email/emails. If anyone knows how to get the fax detection to work let me know I would be gratefull I keep getting fax Detected but no fax extension even though I set it up in the incoming route (one thing I notice is that when you select a fax extension and then apply it disapears) any ideas anyone as I would like the flexibility to do either. Thanks in advance