Summary:ASTERISK-07831: dsp.c listening for wrong fax frequency ...or.... what does faxdetect=outbound do?
Reporter:Mark Edwards (edwar64896)Labels:
Date Opened:2006-09-28 07:32:11Date Closed:2007-01-15 23:17:18.000-0600
Versions:Frequency of
Description:There is a configuration parameter in /etc/asterisk/zapata.conf:
faxdetect=outgoing (or both).

It is clear that the dsp code (dsp.c) is detecting fax tone (at 1100Hz) however this is fax tone from an 'inbound fax call'. I.e., this is the tone that your fax machine generates when you stick a document in it, dial a number and press send.

When you pick up your phone and dial your girlfriend but get a digit wrong, and you get a fax machine, the fax machine is trying to get you to send data, and it does this initially by generating 2100Hz.

So, if I am making an outgoing call and I end up calling a fax machine what is asterisk supposed to be doing with the fax tone that it is hearing? dsp.c is listening on 1100Hz and should be listening on 2100Hz for this scenario to make sense.

On the other hand, I might just not be understanding what faxdetect=outbound actually does...


dsp.c line 254...

static float fax_freq = 1100.0;

Comments:By: jmls (jmls) 2006-11-01 06:38:41.000-0600

ping anyone ?

By: Joshua C. Colp (jcolp) 2006-11-20 20:30:10.000-0600

I'm closing this out as I doubt there's anyone with the real knowledge to answer the question. I highly suggest you hop on to the mailing lists though and see if you can get an answer from Steve Underwood, the fax pro. Peace!

By: Mark Edwards (edwar64896) 2006-11-20 21:26:02.000-0600

Despite the question appended to the summary, this was a genuine bug report. dsp.c is indeed listening for the wrong fax frequency for outbound calls, and as far as I can see the issue isn't resolved.

If I need to report this issue in a different way, please indicate. I'm not sure that "resolving" the issue by closing the bug report with no action is the right way to go about it.

By: Joshua C. Colp (jcolp) 2006-11-20 21:33:41.000-0600

I'll try to see if I can get someone who perhaps knows this... but you might want to track down Steve Underwood on your own too and see what he has to say.

By: Joshua C. Colp (jcolp) 2007-01-15 23:17:17.000-0600

This bug is going nowhere quickly. I assume you haven't gotten an answer and have moved on, and I have got nothing. If you are able to bring something to light feel free to reopen.