Elastix + FreePBX + NVFax Detection

I seem to have a problem with the fax detection in my PBX. When I turn on fax detection for an inbound route I seem to have a problem. Here’s what the CLI shows.

-- Executing [[email protected]:10] NVFaxDetect("SIP/Gizmo-In-00000006", "4,t") in new stack
-- Executing [[email protected]:1] Set("SIP/Gizmo-In-00000006", "__FROM_DID=talk") in new stack
-- Executing [[email protected]:2] NoOp("SIP/Gizmo-In-00000006", "Received an unknown call with DID set to talk") in new stack
-- Executing [[email protected]:3] Goto("SIP/Gizmo-In-00000006", "s,a2") in new stack
-- Goto (from-trunk,s,2)
-- Executing [[email protected]:2] Answer("SIP/Gizmo-In-00000006", "") in new stack
-- Executing [[email protected]:3] Wait("SIP/Gizmo-In-00000006", "2") in new stack
-- Executing [[email protected]:4] Playback("SIP/Gizmo-In-00000006", "ss-noservice") in new stack

For some reason it changes the DID to talk and then gives me the message about the number not in service. If I disable the fax detection on the inbound route it goes to the IVR like it’s supposed to.

What am I doing wrong? What have I missed?


Digium’s Fax For Asterisk has a free single-channel instance and then you can add on more simultaneous calls for a price. You can “buy online” the free and pay versions.

The FAX detection should happen prior to any of the other call handling. If you have the FAX detection set to DAHDI, try setting to SIP and retry. The general call flow should be to listen for FAX tones for the specified time and then resume following the call handling as defined. (Yes, I use SIP FAX detection on my DAHDI channels.)

Elastix 2.0
FreePBX 2.8

I didn’t realize there was a Digium app. How would I go about setting that up? And does it support fax over SIP and IAX?

Forgot to mention, further investigating showed that if I enabled the fax, but disabled follow-me for that extension it also made it work again. I’m not sure what the follow-me has to do with it. The follow me numbers seem to be ok, nothing that should show a number not in service.

Sorry for this non-answer, but if you’re running freepbx 2.7 or fresher I’d suggest not using NVFaxDetect. When moving from 1.4.x to 1.6.x I couldn’t get it to work at all. We’ve moved to the Digium FAX app and it is really works better than any results we ever had with NVFaxDetect.