T.38 Fax Error when using fax_spandsp.so

Community-based Support for users of Free Fax For Asterisk

T.38 Fax Error when using fax_spandsp.so

Postby mgaertne » Tue Feb 26, 2013 6:56 am

Dear Community,
I'm currently setting up a new PBX on basis of a asterisk 1.8.20.1.
Currently I'm struggling with Fax receiption and I did not find any information about my particular problem.
The scenaria:
Asterisk has a SIP-trunk to a provider. Trunk is up and running.
SIP.conf is:
t38pt_udptl = yes,redundancy
faxdetect = yes
[trunk-tl]
type=peer
host=toplink-voice.de
context=Kassel
username=XXXXXXXXXXX
secret=XXXXXXXXXX
qualify=yes
nat=yes
fromuser=D1004701000
outboundproxy=toplink-voice.de
fromdomain=toplink-voice.de

In the extensions I do have:
[macro-fax]
exten => s,1,Set(FAXFILE=/var/spool/asterisk/fax${CALLEDFAX}/${UNIQUEID})
exten => s,n,Set(EXTMAIL=${ARG1})
exten => s,n,Set(EXTNAME=${ARG2})
exten => s,n,ReceiveFAX(${FAXFILE}.tif)
;exten => s,n,rxfax(${FAXFILE}.tif)
exten => s,n,NoOP(/var/lib/asterisk/scripts/mailfax "${CALLERID(num)}" "${CALLEDFAX}" "${EXTNAME}" "${EXTMAIL}" "${FAXFILE}" "${EXTCOMPANY}")
exten => s,n,System(/var/lib/asterisk/scripts/mailfax "${CALLERID(num)}" "${CALLEDFAX}" "${EXTNAME}" "${EXTMAIL}" "${FAXFILE}.tif" "${EXTCOMPANY}")

[Kassel]
exten => fax,1,Macro(fax,"ABCD@mydomain.tld","Mathias")
exten => fax,n,Hangup()
exten => _FAX_NUM,1,Macro(fax,"ABCD@mydomain.tld","Mathias")

I now try to send a FAX via Analog -> ISDN -> Provider ISDN2SIP-GW
towards the Asterisk PBX.
It fails. Here's the verbose output:
== Using SIP RTP CoS mark 5
== Using UDPTL CoS mark 5
-- Executing [XXXX] Macro("SIP/trunk-tl-00000008", "fax,"ABCD@mydomain.tld","Mathias"") in new stack
-- Executing [s@macro-fax:1] Set("SIP/trunk-tl-00000008", "FAXFILE=/var/spool/asterisk/fax//1361876931.13") in new stack
-- Executing [s@macro-fax:2] Set("SIP/trunk-tl-00000008", "EXTMAIL="ABCD@mydomain.tld"") in new stack
-- Executing [s@macro-fax:3] Set("SIP/trunk-tl-00000008", "EXTNAME="Mathias"") in new stack
-- Executing [s@macro-fax:4] ReceiveFAX("SIP/trunk-tl-00000008", "/var/spool/asterisk/fax//1361876931.13.tif") in new stack
-- Channel 'SIP/trunk-tl-00000008' receiving FAX '/var/spool/asterisk/fax//1361876931.13.tif'
== Redirecting 'SIP/trunk-tl-00000008' to fax extension due to CNG detection
asterisk*CLI> [Feb 26 12:08:54] ERROR[15023] res_fax.c: error reading frame while generating CED tone on SIP/trunk-tl-00000008
[Feb 26 12:08:54] ERROR[15023]: res_fax.c:1443 receivefax_t38_init: error reading frame while generating CED tone on SIP/trunk-tl-00000008
asterisk*CLI> [Feb 26 12:08:54] ERROR[15023] res_fax.c: error initializing channel 'SIP/trunk-tl-00000008' in T.38 mode
[Feb 26 12:08:54] ERROR[15023]: res_fax.c:1764 receivefax_exec: error initializing channel 'SIP/trunk-tl-00000008' in T.38 mode
== Spawn extension (Kassel, fax, 1) exited non-zero on 'SIP/trunk-tl-00000008' in macro 'fax'

AS you can see, the error is 15023, error reading frame while generating CED tone.
I have no clue to what to look for.

Any ideas?
This piece is the last hurdle to switch completely onto SIP-Trunks (currently an ISDN PBX is running)
Mathias
mgaertne
Newsterisk
 
Posts: 1
Joined: Tue Feb 26, 2013 6:41 am

Re: T.38 Fax Error when using fax_spandsp.so

Postby abw1oim » Sat Feb 28, 2015 2:02 pm

Hi,

interesting problem what I'm not facing using the same provider (TOPLINK).

Are the udptl-Ports opened in the firewallk and directed to the Asterisk-machine ?
What's happening when You try to use a dedicated number for fax-receiving (instead of faxdetect ?)

And: the T38-params shoild probably be t38pt_udptl = yes,redundancy,maxdatagram=400 - but this shouldn't be the culpritz for this error.
Olaf Winkler
Asterisk- & Database-Solutions
abw1oim
Oldsterisk
 
Posts: 358
Joined: Fri Aug 05, 2011 1:00 am
Location: Germany


Return to Fax For Asterisk

Who is online

Users browsing this forum: No registered users and 1 guest