Summary:ASTERISK-02136: fax detect does not detect fax from Brother Intellafax 4100
Reporter:frank (frank)Labels:
Date Opened:2004-07-28 17:59:35Date Closed:2011-06-07 14:10:28
Versions:Frequency of
Environment:Attachments:( 0) brook-CAS.gsm
( 1) bufford.alaw.gz
( 2) recordtest0.alaw.gz
( 3) snl.alaw.gz
( 4) snl-CAS.gsm
Description:using the fax detect feature, a Brother Intellafax 4100 is not detected as a fax call.


a te405p was connected to the telco.  call comes in on the telco channels.  call is picked up by *.  the Brother is making its normal tones.  * never recognizes it as a fax and does not trigger sending the call to the defined fax extension.

i then called back in on that same channe and DID number from a different fax machine and it was properly detected as a fax.
Comments:By: twisted (twisted) 2004-08-02 21:21:42

please check your configuration for faxdetect= in zapata.conf for the appropriate channels.  

which direction is your faxdetect= line set to?   Also, if swapping the fax machine helped, it could possibly be the fax machine itself, and not asterisk.

Is this coming in from the outside?  if so, are the two machines on different pstn lines?  regardless of the channel they come in on the te405, if they're on two different analog lines on the PSTN, there are too many factors to accurately troubleshoot this.

Please check/confirm/answer these statements to continute this bug.

By: frank (frank) 2004-08-03 06:35:25

for the all channels that are coming from the pstn, we have faxdetect=incoming.
this works for us for many other fax machines so far.

listening to the fax machine in question on the phone, it sounds as though the CNG tones are a little different than some of the others that just make the beep kind of sound.

this fax machine is calling from some place on the PSTN, through the pstn, into the te405, out of another one of the pri ports on the 405 to a pri-fax card.

so, there is only really one fax machine involved and we have a pri-fax card attached to the te405.  the sending fax machine is on an analog line directly attached to the telco pstn (centrex line).

i can have this fax machine send you a fax for testing as well.

it appears as though the CNG tones of this fax machine are confusing faxdetect.

By: twisted (twisted) 2004-08-03 15:56:00

if you could find me on irc, i'm in #asterisk or #asterisk-bugs as twisted.

By: Olle Johansson (oej) 2004-08-08 15:06:50

Please report according to instructions. (See bugs.digium.com)
* What version of Asterisk?
* On what platform?

By: frank (frank) 2004-08-08 16:06:06

tested with CVS from 7/17/04.
compiled on RH8
using TE405p for connection to telco with a t1 b8zs/esf

zapata.conf lines of interest
channel => 1-6

By: frank (frank) 2004-08-10 11:53:42

twised, as discussed i have captured the fax "tones" from this machine with record().  i am uploading it as brook-CAS.gsm

By: frank (frank) 2004-08-10 11:57:34

i am uploading another gsm from a fax machine's tones that was not detected by faxdetect.  i do not know the make/model of this one yet. but will post it as soon as i find out.

i am uploading it as snl-CAS.gsm

By: frank (frank) 2004-08-11 13:05:59

the snl-CAS file is from a Brother Intelli 2800

By: Brian West (bkw918) 2004-08-11 23:10:23

Fax detect doesn't work with all fax machines.

By: Ryan Courtnage (rcourtna) 2004-08-16 20:29:58

Reminder sent to bkw918


> "Fax detect doesn't work with all fax machines."

Why is this bug closed then?  (Unless it's designed not to work with all fax machines)

By: frank (frank) 2004-12-06 17:38:12.000-0600

more information from author of faxdetect feature, steve underwood.

By: frank (frank) 2004-12-06 17:38:51.000-0600

from steve underwood...

The dominant frequency in these samples is 1100Hz, so the sound is kind
of coming through. Its amplitude keeps pumping up and down, though.
Putting it through the GSM compressor doesn't help with identifying what
exactly is happening. The two machines seem to be doing similar, but
slightly different things.

Can you make an uncompressed recording from these machines, and one from
a good machine for comparison?


By: frank (frank) 2004-12-06 17:46:32.000-0600

recordtest0.alaw is from the fax machine that works fine.
bufford.alas is from the "Brook" fax machine noted before.
snl.alaw is from the Brother Intelli 2800 noted before.

now that this information is posted and recorded, I suppose you can/will re-close the bug.

By: Olle Johansson (oej) 2004-12-19 07:47:06.000-0600

Closed on request by reporter.

By: frank (frank) 2004-12-19 09:04:44.000-0600

Reminder sent to oej


i did not suggest that you close this bug.  it is still a bug. my comment was that i suspected you would close the bug since that is what was done before... even though this is still a bug.  i think the resaon give before for closing this bug report was "Fax detect doesn't work with all fax machines."  

perhaps this behavior is by design.  but i felt it was a bug.

if it is not a bug and by design, could we document which fax machines this feature is designed not to work with?