I have recently upgraded my Asterisk from 1.4x.x to 1.8.7.1. This successfully broke Digium’s Fax for Asterisk until I downloaded the appropriate updated files for 1.8. These have now been installed and fax show capabilities results as follows:
Type : DIGIUM
Description : Digium FAX Driver
Capabilities : SEND RECEIVE T.38 G.711 MULTI-DOC
However, the behaviour of the fax extensions and inbound fax routes seems to have changed - (or maybe I never fully understood it).
My machine and OS is as follows: (Centos 5)
# uname -a
Linux pbx.check-flight.com. 2.6.18-238.19.1.el5 #1 SMP Fri Jul 15 07:32:29 EDT 2011 i686 i686 i386 GNU/Linux
# getconf LONG_BIT
32
I have carefully followed all of the installation guidance given in the Digium Fax for Asterisk Admin Manual, including running the benchfax utility and selecting the correct version of the files for my particular OS and machine and modifying the /etc/asterisk/modules.conf files to include:
noload => app_fax.so
noload => res_fax_spandsp.so
(this being to avoid conflicts with the previously installed SpanDSP library)
I now have two apparent problems, which may well be inter-related…
1) SIP Extensions:
Given a SIP extension, (in my case 300), I have enabled Fax and given an email address. Now as I recall previously, (under Asterisk 1.4), the extension would continue to operate as a regular extension inasmuch I could call it from any other extension, the phone would ring and a conversation could take place. However if I sent a fax to that extension, then it would detect the fax tones and receive it instead of putting the call through to the phone. This no longer happens. All calls go straight to fax and the phone never rings. As I can’t find a decent description of the intended behaviour (the only hint being “Enable this user to receive faxes”), I’m not sure if this behaviour is intended under Asterisk 1.8 or not. I just seem to recall there was some kind of tone detection before.
Even then, all faxes sent to the extension fail: (The fax test source is Zoiper communicator registered as another SIP extension and sending a TIFF file. Zoiper is supposed to be T38 aware - but I can’t get this working from a “regular” fax machine either).
pbx*CLI> fax show stats
FAX Statistics:
Current Sessions : 0
Reserved Sessions : 0
Transmit Attempts : 0
Receive Attempts : 5
Completed FAXes : 0
Failed FAXes : 5
Digium G.711
Licensed Channels : 1
Max Concurrent : 0
Success : 0
Switched to T.38 : 0
Canceled : 0
No FAX : 0
Partial : 0
Negotiation Failed : 0
Train Failure : 0
Protocol Error : 0
IO Partial : 0
IO Fail : 0
Digium T.38
Licensed Channels : 1
Max Concurrent : 1
Success : 0
Canceled : 0
No FAX : 3
Partial : 0
Negotiation Failed : 0
Train Failure : 2
Protocol Error : 0
IO Partial : 0
IO Fail : 0
2) Inbound Routes
Under the inbound routes, I have a “Fax Detect” option. “Yes” means that Asterisk will try to determine if the inbound call is either a fax or a voice call. I then have three further options under “Fax Detection Type”.
a) DAHDI (which I presume does not apply to me as I have no POTS hardware attached)
b) SIP (T38) - which I have selected
c) NV Fax Detect (which requires NV Fax Detect to be installed and recognised by Asterisk) This is greyed out and various articles I have read imply that NV Fax Detect is not compatible with Asterisk 1.8 and I think this is part of the app-fax.so module that is set to ‘noload’ (see above) to avoid conflicts with the Digium modules.
Basically, either with ‘SIP’ or ‘DAHDI’ detection selected, this just doesn’t work for inbound SIP faxes. Incoming fax calls are never recognised and the calls always drop through the to standard destination selected for that route.
It may well be that my SIP provider does not support T38 for the inbound trunk, but even so, under Asterisk 1.4 and NV Fax Detect, inbound faxes were correctly recognised and processed under G.711 capabilities. This now appears to be broken with the lack of NV Fax Detect.
Does anyone have any ideas how I can solve this?