[asterisk-bugs] [Asterisk 0012382]: Add dialtone detection to chan_zap FXO devices

[noreply at bugs.digium.com]

A NOTE has been added to this issue. 
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http://bugs.digium.com/view.php?id=12382 
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Reported By:                one47
Assigned To:                
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Project:                    Asterisk
Issue ID:                   12382
Category:                   Channels/chan_zap
Reproducibility:            N/A
Severity:                   feature
Priority:                   normal
Status:                     new
Asterisk Version:           1.2.25 
SVN Branch (only for SVN checkouts, not tarball releases): N/A 
SVN Revision (number only!):  
Disclaimer on File?:        N/A 
Request Review:              
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Date Submitted:             04-08-2008 09:05 CDT
Last Modified:              04-08-2008 09:08 CDT
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Summary:                    Add dialtone detection to chan_zap FXO devices
Description: 
In the UK, analogue lines can only be hung-up by the caller. If asterisk is
not the caller, then when asterisk hangs up, it may well have no effect,
but asterisk thinks the line is available! This can cause a "special" kind
of glare - This feature was abused as a Phreaking tool for many years...
British telecom insist that this behaviour cannot be disabled.

The only workaround to this that I have been able to come up with is
dialtone detection before dialing. I believe this will also be a popular
feature for people with lines that do not offer an immediate dialtone.

The attached patch adds a new DSP mode of "WAITFORDIALTONE" which will use
the existing dialtone detection code - I have extended it to work for UK
users (progmode=uk in zapata.conf) It also adds a new zapata.conf parameter
of "waitfordialtone" which takes a numeric parameter to specify how long in
ms to wait for a dialtone before giving up and failing the call.
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---------------------------------------------------------------------- 
 one47 - 04-08-08 09:08  
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Note. I particularly dislike the way I have changed the UK frequency
#defines to:

#define HZ_350UK       0
#define HZ_400UK       1
#define HZ_440UK       2

I would welcome a suggestion for a better way to handle that! All other
comments also welcome as C programming is not my strength... 

Issue History 
Date Modified   Username       Field                    Change               
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04-08-08 09:08  one47          Note Added: 0085119                          
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