I’m trying to send fax from Asterisk 13.1-cert2 using res_fax and res_fax_spandsp.
It works fine when sending a single tif file but I would need to be able to send multiple files. E.g. a generic header page followed by a page with more specific content.
I set up a simple test in extensions.conf
exten => s,1,SendFAX(/var/asterisk/linehandler/faxpage1.tif&/var/asterisk/linehandler/faxpage2.tif,d)
exten => s,n,Hangup
And I execute it from Asterisk CLI with the following command (output included)
*CLI> channel originate SIP/f_digium_fax/0709931762 extension s@test_fax
== Using SIP RTP CoS mark 5
– Called f_digium_fax/0709931762
– SIP/f_digium_fax-00000000 is making progress
– SIP/f_digium_fax-00000000 is ringing
– SIP/f_digium_fax-00000000 answered
– Executing [s@test_fax:1] SendFAX(“SIP/f_digium_fax-00000000”, “/var/asterisk/linehandler/faxpage1.tif&/var/asterisk/linehandler/faxpage2.tif,d”) in new stack
– Channel ‘SIP/f_digium_fax-00000000’ sending FAX:
[Feb 15 20:03:51] ERROR[C-00000000]: res_fax.c:1174 fax_session_reserve: Could not locate a FAX technology module with capabilities (SEND,MULTI_DOC)
[Feb 15 20:03:51] ERROR[C-00000000]: res_fax.c:2729 sendfax_exec: Unable to reserve FAX session.
== Spawn extension (test_fax, s, 1) exited non-zero on ‘SIP/f_digium_fax-00000000’
It seems as I’m missing fax capability for MULTI_DOC
*CLI> fax show capabilities
Registered FAX Technology Modules:
Type : Spandsp
Description : Spandsp FAX Driver
Capabilities : SEND RECEIVE T.38 G.711 GATEWAY
1 registered modules
To me it seems as res_fax_spandsp does not support sending multiple documents? Is that correct or am I doing something wrong?
I also tried a different approach in extensions.conf
exten => s,1,SendFAX(/var/asterisk/linehandler/faxpage1.tif,d)
exten => s,1,SendFAX(/var/asterisk/linehandler/faxpage2.tif,d)
exten => s,n,Hangup
I this case the first SendFAX is successfull but the receiving side is hanging up so the negotiation for the second SendFAX failes.
This sounds as a correct behaviour to me. The receiver does not expect a new fax session during the same call.
Should I expect different behaviour in this case?
I found a topic related to this but unfortunatly there were no answers to it.
See res_fax: Errors when sending multiple documents
Based on the above information I don’t know how to proceed. Is there any other FAX module available? res_fax_digium is not supported in Asterisk 13 so I guess thats not an option.
I appreciate all kind of feedback in this matter.
My setup is Asterisk 13.1-cert2 running on Debian (Jessie) OS.
Using SIP from Asterisk to a local Digium G100 gateway with a E1 PRI connection directly to our telecom provider.