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

[Asterisk Bug Tracker]

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/NewFeature
Reproducibility:            N/A
Severity:                   feature
Priority:                   normal
Status:                     ready for testing
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:             2008-04-08 09:05 CDT
Last Modified:              2008-09-19 09:46 CDT
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Summary:                    [patch] 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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 (0092700) fleed (reporter) - 2008-09-19 09:46
 http://bugs.digium.com/view.php?id=12382#c92700 
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This is brilliant, I've been waiting for this patch for a while now, so I
can get dialing to work correctly on my sluggish-dialtone line. 

I've had to make a slight change to it so that it would work with the type
of dialtone we use here in Brazil. It is 425Hz for dialtone and the same
425Hz for ringing, though interrupted. So I added DSP_TONE_STATE_RINGING to
the trigger, with its own count. The default count of 10 chunks seems to be
working okay so far. I also added one line so that the dialtone waiting
time is displayed in 'zap show channel '. 
Thanks a lot! 

Issue History 
Date Modified    Username       Field                    Change               
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2008-09-19 09:46 fleed          Note Added: 0092700                          
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