2100 Hz is the ANS tone from the receiving side of the fax call. That's what I detect on my outbound calls. On Thu, Apr 14, 2011 at 12:57 PM, romon.zaman <romon.zaman@gmail.com> wrote:

hello MC, you are right.. before this published here, you help me to get a solution.

actually, my fax machine was not sending standard fax tone. but it worked with actual tone frequency.

so, if someone ever face this problem, recommendation is to get pcap file and extract audio file from RTP with wireshark and analyze audio with audicity to get exact frequency of tone.

and when u use tone_detect with exact tone frequency, it will work perfectly.

thanks for your help

----- Original Message ----- *From:* Michael Collins <msc@freeswitch.org> *To:* FreeSWITCH Users Help <freeswitch-users@lists.freeswitch.org> *Sent:* Thursday, April 14, 2011 10:43 PM *Subject:* Re: [Freeswitch-users] fax tone detection failed

On Wed, Apr 13, 2011 at 5:16 AM, romon.zaman <romon.zaman@gmail.com>wrote:

...

hi,

i am trying to detect fax tone on outgoing calls. here is my javascript code

+++++++++++++++++++++++

session1 = new Session("{ignore_early_media=false}sofia/gateway/flowroute/"+argv[0]+"");

session1.execute("tone_detect", "fax 1100 r +30000 set 'fax_tone_detected=true' 1"); msleep(argv[1]); session1.hangup();

++++++++++++++++++++++++

i checked pcap file and using wireshark , i can hear sone tone on rtp audio playback.

but freeswitch cant detect that..

is there any other solution to find out specific tone like fax??

thanks in advance

Was this the one we talked about yesterday where your fax machine was really spitting out a tone around 2096Hz?

-MC

__________ Information from ESET Smart Security, version of virus signature database 6041 (20110414) __________

The message was checked by ESET Smart Security.

http://www.eset.com

_______________________________________________ FreeSWITCH-users mailing list FreeSWITCH-users@lists.freeswitch.org http://lists.freeswitch.org/mailman/listinfo/freeswitch-users UNSUBSCRIBE:http://lists.freeswitch.org/mailman/options/freeswitch-users http://www.freeswitch.org

This would be awesome because (as you say) you can't count on the receiving machine sending the 2100Hz tone... On Thu, Apr 14, 2011 at 1:58 PM, Steve Underwood <steveu@coppice.org> wrote:

On 04/15/2011 01:32 AM, Christopher Rienzo wrote:

...

2100 Hz is the ANS tone from the receiving side of the fax call. That's what I detect on my outbound calls. An answering machine sends 2100Hz, but its very unreliable to rely on hearing it. In spandsp there is a module which does a much more thorough job of detecting a FAX machine. It will accept the V.21 preamble, which normally follows the 2100Hz tone, as a substitute for the 2100Hz itself. That way a call which starts passing audio a bit late (which they often do) still results in proper FAX detection. We need to expose that functionality in FreeSwitch, but have not done so yet.

Steve

-- Kristian Kielhofner

On 04/15/2011 12:43 AM, Michael Collins wrote:

On Wed, Apr 13, 2011 at 5:16 AM, romon.zaman <romon.zaman@gmail.com <mailto:romon.zaman@gmail.com>> wrote:

hi,

i am trying to detect fax tone on outgoing calls. here is my javascript code

+++++++++++++++++++++++

session1 = new Session("{ignore_early_media=false}sofia/gateway/flowroute/"+argv[0]+"");

session1.execute("tone_detect", "fax 1100 r +30000 set 'fax_tone_detected=true' 1"); msleep(argv[1]); session1.hangup();

++++++++++++++++++++++++

i checked pcap file and using wireshark , i can hear sone tone on rtp audio playback.

but freeswitch cant detect that..

is there any other solution to find out specific tone like fax??

thanks in advance

Was this the one we talked about yesterday where your fax machine was really spitting out a tone around 2096Hz?

Of course it spits out around 2096Hz. An answering FAX machine sends a burst of 2100Hz tone, and then V.21 preamble. Its the calling machine which sends 1100Hz. Steve