FreePBX 2.9 and Asterisk 1.8 with Fax in SpanDSP mode

I’m writing in regards to my ticket

Situation - Asterisk 1.8.x.x, compiled with app_fax module instead of res_fax + res_fax_spandsp. So, ReceiveFax and SendFax applications are present in system and system is able to send and receive faxes. But, during initial fax configuration, FreePBX Fax module is incorrectly detecting Asterisk fax module configuration, which causes it to try to check if res_fax_spandsp is loaded, even though it already has ReceiveFax application found. That results in context [ext-fax] NOT being generated at all.

It happens here:, line 198:

$response = $astman->send_request('Command', array('Command' => $module_show_command.'res_fax_spandsp')); $fax['spandsp'] = preg_match('/[1-9] modules loaded/', $response['data']) ? true : false;

But, you can’t build Asterisk 1.8 with app_fax without disabling res_fax and res_fax_spandsp, which depends on res_fax!

From Asterisk’s make menuselect:
app_fax Simple FAX Application Depends on: spandsp(E) Conflicts with: res_fax(M)

So, after that line in I just added $fax['spandsp'] = true; and system started to work without any issues!

I believe this one should be fixed, somehow system needs to know that if app_fax is present - it shouldn’t try to check if res_fax or res_fax_spandsp loaded.

Well FreePBX is only setup with the Fax module to support res_fax with either res_fax_digium or res_fax_spandsp.

Please move to res_fax and app_fax has been deprecated from my understanding and there is not support in FreePBX for it anymore.

That’s kinda strange, why it detects that fax subsystem is present and stops saying “No fax modules detected”? And app_fax is not deprecated, it’s supported by Asterisk, you just need to choose which one you want to build, that’s it. And I really don’t like res_fax because it requires license key to be entered for every PBX, and we deploy a lot of PBXs so it’s not convenient at all! So I’d like to see FreePBX supporting app_fax, because it’s not a third party module of any kind, it’s still in Asterisk

Or wait, my mistake, res_fax_spandsp doesn’t require license, it was res_fax_digium which required one. Thanks!

Dear Lt_Flash,
I have a box where I loaded Digium’s FFA. I have FFA and two purchased licenses on another box that works fine, but I don’t want to use FFA because I am having troubles.

I want to use the FreePBX Fax in and out through the Recordings interface, but I am having trouble making SpanDSP work.

In /etc/asterisk/modules.conf I have this:

;noload =>
;noload =>
noload =>

I can use an Extension Recordings interface to navigate to a file and send it, but on the other end they are not receiving fax. Fax answer on an Extension where I have Fax Enable checked and the Inbound Route set to Detect Fax and send to a Fax Enabled Extension.

Could you point me in the right direction? A Little nudge?

I wish there was a comprehensive guide to making fax work with FreePBX!

Thanks, and Merry Christmas

Unfortunately there is no guide. You did not mention how you built your system so you have to look through the logs and figure out what is going on.

The easiest way to get a working system is to install the FreePBX distro. We have done the hard work for you. Asterisk and SpanDSP are preconfigured.