Add Fax capabilities in Asterisk >=13

AsteriskRecomplieWithSpanDspBeginning with Asterisk 13 Digium will no longer make available the res_fax_digium module (FFA or commercial versione): if you want fax capabilities you should use the res_fax_spandsp module.

Yes, I know, it is possible to use IAX modem, but sometimes I prefer use T.38 protocolo to receive fax, and only res_fax_spandsp can support this protocol. I’ll show hot to install res_fax_spandsp in a working IncrediblePbx 13 inst.

1) Download last spandsp snapshot from to /usr/src: in my case spandsp-20160212.tar.gz
2) Uncompress tgz file
3) Compile and install spandsp

sudo make install

4) Add the spandsp Library to system library paths

nano /etc/

Add the next line, save & close


5) Reboot the system and check the boot log
6) Recompile Asterisk

cd /usr/src/asterisk-13*
make menuselect

Check that in Resource Modules spandsp enabled, and recompile asterisk

make install

7) Reboot the system and check the boot and Asterisk log
8) You can verify that spandsp is working with Asterisk by issuing the following command from the Asterisk CLI

module show like

Asterisk Docs – Spandsp