Re: [asterisk-users] Too Few Fax Detections

2011-01-07 Thread Tom Rymes

On Jan 6, 2011, at 8:56 AM, Kevin P. Fleming wrote:

 On 01/05/2011 08:12 PM, Thomas Rymes wrote:
 OK, after my last message about fax detection, I feel a bit better informed 
 and able to press forward. I started looking into this because I was getting 
 lots of false positive fax detection errors in the logs with faxdetect=both 
 set in chan_dahdi.conf.
 
 Anyhow, I do not currently use fax detection, and we have a dedicated Fax 
 DID on our PRI, so setting faxdetect=no works fine. Having said that, I 
 would like to sort it out as I may want to use fax detection in the future. 
 Unfortunately, I seem to be having odd results. I set faxdetect=incoming 
 last night and restarted dahdi and asterisk. Since that time, we have 
 received 17 faxes, but I only have three fax detections in my asterisk log, 
 so far as I can tell:
 
 # grep -i fax /var/log/asterisk/full
 [Jan  5 05:53:39] NOTICE[6686] chan_dahdi.c: Fax detected, but no fax 
 extension
 [Jan  5 10:24:27] NOTICE[11834] chan_dahdi.c: Fax detected, but no fax 
 extension
 [Jan  5 11:48:52] NOTICE[13804] chan_dahdi.c: Fax detected, but no fax 
 extension
 
 All three calls listed are indeed fax calls, and since there is no fax 
 extension in that context, the call just proceeds along as if nothing 
 happened (which is appropriate).
 
 My question is this: If I have received 17 faxes since enabling fax 
 detection, shouldn't I see ~17 entries in the log?
 
 How are you delivering the inbound FAX calls to your FAX machine? If you are 
 sending them back out a DAHDI channel (to an FXS port on an analog card, for 
 example), then as soon as the two channels are bridged the audio never comes 
 up to Asterisk (under normal circumstances), it stays in DAHDI, so the 
 Asterisk DSP can't detect the CNG tone. If the FAX machine answers the 
 incoming call fairly quickly, there may not be any opportunity for the CNG to 
 be detected. In addition, you may not be even receiving any audio from the 
 calling FAX machine until you answer the incoming channel (depending on your 
 PRI provider).
 
 If you want to have the best chance to detect each incoming FAX using the 
 Asterisk DSP, you'll have to answer the incoming channel as soon as it hits 
 the dialplan, then wait 3 or 4 seconds, then send the call onwards to your 
 actual FAX machine. FAX detection is really expected to be used on calls that 
 would otherwise be answered by a non-FAX endpoint (IVR, voicemail, user with 
 a phone, etc.)

That does make sense: the incoming calls are directed to a FreePBX ring group 
consisting of three IAXModems handled by HylaFAX, and I am fairly certain that 
they answer the call nearly instantaneously. 

I do realize that the detection is really intended for non-dedicated lines; I'm 
just trying to ensure it works before I start using it. 

Thanks for the response.

Tom
--
_
-- Bandwidth and Colocation Provided by http://www.api-digital.com --
New to Asterisk? Join us for a live introductory webinar every Thurs:
   http://www.asterisk.org/hello

asterisk-users mailing list
To UNSUBSCRIBE or update options visit:
   http://lists.digium.com/mailman/listinfo/asterisk-users


[asterisk-users] Too Few Fax Detections

2011-01-06 Thread Thomas Rymes
OK, after my last message about fax detection, I feel a bit better informed and 
able to press forward. I started looking into this because I was getting lots 
of false positive fax detection errors in the logs with faxdetect=both set in 
chan_dahdi.conf.

Anyhow, I do not currently use fax detection, and we have a dedicated Fax DID 
on our PRI, so setting faxdetect=no works fine. Having said that, I would like 
to sort it out as I may want to use fax detection in the future. Unfortunately, 
I seem to be having odd results. I set faxdetect=incoming last night and 
restarted dahdi and asterisk. Since that time, we have received 17 faxes, but I 
only have three fax detections in my asterisk log, so far as I can tell:

# grep -i fax /var/log/asterisk/full
[Jan  5 05:53:39] NOTICE[6686] chan_dahdi.c: Fax detected, but no fax extension
[Jan  5 10:24:27] NOTICE[11834] chan_dahdi.c: Fax detected, but no fax extension
[Jan  5 11:48:52] NOTICE[13804] chan_dahdi.c: Fax detected, but no fax extension

All three calls listed are indeed fax calls, and since there is no fax 
extension in that context, the call just proceeds along as if nothing happened 
(which is appropriate). 

My question is this: If I have received 17 faxes since enabling fax detection, 
shouldn't I see ~17 entries in the log?

Assuming the answer to that question is yes, what might be causing the system 
to not detect faxes on the other 14 calls?

Many thanks,

Tom
--
_
-- Bandwidth and Colocation Provided by http://www.api-digital.com --
New to Asterisk? Join us for a live introductory webinar every Thurs:
   http://www.asterisk.org/hello

asterisk-users mailing list
To UNSUBSCRIBE or update options visit:
   http://lists.digium.com/mailman/listinfo/asterisk-users


Re: [asterisk-users] Too Few Fax Detections

2011-01-06 Thread Kevin P. Fleming

On 01/05/2011 08:12 PM, Thomas Rymes wrote:

OK, after my last message about fax detection, I feel a bit better informed and 
able to press forward. I started looking into this because I was getting lots 
of false positive fax detection errors in the logs with faxdetect=both set in 
chan_dahdi.conf.

Anyhow, I do not currently use fax detection, and we have a dedicated Fax DID 
on our PRI, so setting faxdetect=no works fine. Having said that, I would like 
to sort it out as I may want to use fax detection in the future. Unfortunately, 
I seem to be having odd results. I set faxdetect=incoming last night and 
restarted dahdi and asterisk. Since that time, we have received 17 faxes, but I 
only have three fax detections in my asterisk log, so far as I can tell:

# grep -i fax /var/log/asterisk/full
[Jan  5 05:53:39] NOTICE[6686] chan_dahdi.c: Fax detected, but no fax extension
[Jan  5 10:24:27] NOTICE[11834] chan_dahdi.c: Fax detected, but no fax extension
[Jan  5 11:48:52] NOTICE[13804] chan_dahdi.c: Fax detected, but no fax extension

All three calls listed are indeed fax calls, and since there is no fax 
extension in that context, the call just proceeds along as if nothing happened 
(which is appropriate).

My question is this: If I have received 17 faxes since enabling fax detection, 
shouldn't I see ~17 entries in the log?


How are you delivering the inbound FAX calls to your FAX machine? If you 
are sending them back out a DAHDI channel (to an FXS port on an analog 
card, for example), then as soon as the two channels are bridged the 
audio never comes up to Asterisk (under normal circumstances), it stays 
in DAHDI, so the Asterisk DSP can't detect the CNG tone. If the FAX 
machine answers the incoming call fairly quickly, there may not be any 
opportunity for the CNG to be detected. In addition, you may not be even 
receiving any audio from the calling FAX machine until you answer the 
incoming channel (depending on your PRI provider).


If you want to have the best chance to detect each incoming FAX using 
the Asterisk DSP, you'll have to answer the incoming channel as soon as 
it hits the dialplan, then wait 3 or 4 seconds, then send the call 
onwards to your actual FAX machine. FAX detection is really expected to 
be used on calls that would otherwise be answered by a non-FAX endpoint 
(IVR, voicemail, user with a phone, etc.)


--
Kevin P. Fleming
Digium, Inc. | Director of Software Technologies
445 Jan Davis Drive NW - Huntsville, AL 35806 - USA
skype: kpfleming | jabber: kflem...@digium.com
Check us out at www.digium.com  www.asterisk.org

--
_
-- Bandwidth and Colocation Provided by http://www.api-digital.com --
New to Asterisk? Join us for a live introductory webinar every Thurs:
  http://www.asterisk.org/hello

asterisk-users mailing list
To UNSUBSCRIBE or update options visit:
  http://lists.digium.com/mailman/listinfo/asterisk-users