asterisk users - Jan 2007 - OT: Asterisk 1.2.X, IAXModem 0.2.0 + HylaFAX+ 5.0.3 interop probl em

When I have HylaFAX answer a call redirected to the fax extension in
Asterisk when it detects CNG, Asterisk hangs up:

Jan 30 14:32:59 VERBOSE[1098]:     -- IAX2/ttyIAX0552/12 is ringing
Jan 30 14:32:59 VERBOSE[1098]:     -- IAX2/ttyIAX0552/12 answered Zap/23-1
Jan 30 14:32:59 DEBUG[1098]: Ooh, voice format changed to 8
Jan 30 14:33:01 VERBOSE[1098]:     -- Channel 0/23, span 1 got hangup
Jan 30 14:33:01 DEBUG[1098]: Didn't get a frame from channel: Zap/23-1
Jan 30 14:33:01 DEBUG[1098]: Bridge stops bridging channels Zap/23-1 and
IAX2/ttyIAX0552/12
Jan 30 14:33:01 DEBUG[1098]: We're hanging up IAX2/ttyIAX0552/12 now...
Jan 30 14:33:01 VERBOSE[1098]:     -- Hungup 'IAX2/ttyIAX0552/12'
Jan 30 14:33:01 DEBUG[1098]: Exiting with DIALSTATUS=ANSWER.

When I direct-dial HylaFAX with a handset, HylaFAX answers, I hear it's tone
from IAXmodem, and Asterisk does NOT hang up. 

alaw and slin codecs do the same thing. 

fax extension:

exten => fax,1,Dial(IAX2/ttyIAX0552/${DNID})

direct extension:

exten => 0552,1,Dial(IAX2/ttyIAX0552/${DNID})

Anybody got a hint?

Colin Anderson wrote:
>When I have HylaFAX answer a call redirected to the fax extension in
>Asterisk when it detects CNG, Asterisk hangs up:
>
>Jan 30 14:32:59 VERBOSE[1098]:     -- IAX2/ttyIAX0552/12 is ringing
>Jan 30 14:32:59 VERBOSE[1098]:     -- IAX2/ttyIAX0552/12 answered Zap/23-1
>Jan 30 14:32:59 DEBUG[1098]: Ooh, voice format changed to 8
>Jan 30 14:33:01 VERBOSE[1098]:     -- Channel 0/23, span 1 got hangup
>Jan 30 14:33:01 DEBUG[1098]: Didn't get a frame from channel: Zap/23-1
>Jan 30 14:33:01 DEBUG[1098]: Bridge stops bridging channels Zap/23-1 and
>IAX2/ttyIAX0552/12
>Jan 30 14:33:01 DEBUG[1098]: We're hanging up IAX2/ttyIAX0552/12 now...
>Jan 30 14:33:01 VERBOSE[1098]:     -- Hungup 'IAX2/ttyIAX0552/12'
>Jan 30 14:33:01 DEBUG[1098]: Exiting with DIALSTATUS=ANSWER.
>
>When I direct-dial HylaFAX with a handset, HylaFAX answers, I hear it's
tone
>from IAXmodem, and Asterisk does NOT hang up. 
>
>alaw and slin codecs do the same thing. 
>
>fax extension:
>
>exten => fax,1,Dial(IAX2/ttyIAX0552/${DNID})
>
>direct extension:
>
>exten => 0552,1,Dial(IAX2/ttyIAX0552/${DNID})
>
>Anybody got a hint?
>
I cannot help but think that the fax detection has something to do with 
this.

Remember that fax detection does not even start until after the call is 
answered in the first place.  So you must answer the call in the 
dialplan - even if you just then play a ringing sound in the background 
for a few seconds, before then directing the call on into the dialplan.

My guess is that something within Asterisk is not working right when a 
call is answered by iaxmodem and then faxdetect determines that it's a 
fax and then attempts to send it to the "fax" extension - only to find
that it's the same place, really, but now iaxmodem thinks that it is 
busy with the call that faxdetect just stole from it.

Faxdetect is a precarious feature - use it sparingly, use it cautiously.

Lee.