Summary:ASTERISK-02569: [request] Detect dialtone on Zap channels before dialing
Reporter:paradise (paradise)Labels:
Date Opened:2004-10-08 16:05:09Date Closed:2011-06-07 14:05:26
Versions:Frequency of
Description:i'm under the impression that this feature is not available in asterisk.

i use PSTN lines connected to TA750 -> TE405P.
when dialing...if the pstn line is out of order (no dialtone) i get dead air, nothing will happen and * shows that the zap channel is answered.
i know that by adding 'w' to the dialed number we can reduce false alarms. but when the pstn line is really out of order there is no solution.
btw, it's very strange to me when normal modems can detect dialtone but * not.


my suggestion is:
Adding an option to Dial() to detect dialtone before dialing or report the channel as unavailable on failure.

Comments:By: Mark Spencer (markster) 2004-10-08 18:55:58

DSP already has some routines in it to do dialtone detect.

By: paradise (paradise) 2004-10-08 23:57:52

if it exists, why my Dial() command still uses the channels with no dialtone.
any missing configs?
i'm using * 1.0.1

edited on: 10-09-04 08:56

By: Mark Spencer (markster) 2004-10-09 10:13:30

I'm saying there is code in the struct ast_dsp which can already be used to detect U.S. dialtone.  That might be a starting point for any work in this direction.  I think it would need to be a part of the channel driver rather than part of the dial app, i would assume.

By: paradise (paradise) 2004-10-09 13:47:12

I've seen this code before
} else if (pair_there(hz[HZ_350], hz[HZ_440], hz[HZ_480], hz[HZ_620], dsp->genergy)) {
   newstate = TONE_STATE_DIALTONE;

but it's hard to me to find out when * uses this part of code.
it seems that it's used when callprogress is on. am i right?
I would be a good coder if somebody help me to find out what is happening inside.

By: paradise (paradise) 2004-10-09 13:53:23

according to the mentioned code in dsp.c:
Isn't better to use the dialtone specs. from indications.conf instead of hard coding it?

By: paradise (paradise) 2004-10-18 05:07:59

just another question:
does * try to detect dialtone before dialing, if i set callproress=yes
in zapata.conf.

By: twisted (twisted) 2004-11-14 21:06:58.000-0600

Is a patch going to be added for this?  If not, I suggest adding this to the wiki under the wishlist.

By: Russell Bryant (russell) 2004-11-21 01:03:21.000-0600

I'm going to go ahead and close this one for now.

I would recommend posting it to a wishlist on the wiki.  Also, you can stir up some discussion about implementing this on IRC or the mailing lists.  

Feel free to re-open or create a new bug if a patch becomes available.