[asterisk-bugs] [Asterisk 0013716]: [patch] Prevent false answer of channel when going off-hook

[Asterisk Bug Tracker]

A NOTE has been added to this issue. 
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http://bugs.digium.com/view.php?id=13716 
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Reported By:                alecdavis
Assigned To:                
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Project:                    Asterisk
Issue ID:                   13716
Category:                   Channels/chan_dahdi
Reproducibility:            always
Severity:                   minor
Priority:                   normal
Status:                     new
Asterisk Version:           1.6.0 
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:             2008-10-16 04:58 CDT
Last Modified:              2008-10-16 05:13 CDT
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Summary:                    [patch] Prevent false answer of channel when going
off-hook
Description: 
With answeronpolarityswitch=no asterisk answers channel soon after dialout
has started, or perhaps just finished. Causing Ringing for the caller to
stop, then silence for a while as the call is setup, then telco ringing is
heard and call proceedes as normal.
 
With answeronpolarityswitch=yes asterisk answers channel as soon as the
line goes off-hook. The user hears a very short Ring from Asterisk, long
silence as digits are dialled out and call is setup, then finally telco
ring is heard.
This is caused in our case because the line does a polarity reversal when
going off hook.

I have modifed wctdm.c that adds polarityignore in 3 sections of the code,
strcut fxo, wctdm_voicedaa_check_hook and wctdm_hooksig.

I'll upload for your comment, but welcome any advice if there is a better
way.
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---------------------------------------------------------------------- 
 (0093813) alecdavis (reporter) - 2008-10-16 05:13
 http://bugs.digium.com/view.php?id=13716#c93813 
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Commented version of debug log. should have done this orignally.
If the polarity reversal (2nd event) wasn't ingored (3rd event), asterisk
would have ansered the call.

debug enabled in wctdm: events from /var/log/debug
<================Start Call=======================================>
Oct 16 22:17:31 astrid kernel: [3841192.791833] Setting FXO hook state 2
to (09), PolIgnore to (1)
<================Problem OFF HOOK line Reversal===================>
Oct 16 22:17:31 astrid kernel: [3841192.960332] 738779686 Polarity
Reversed (-1 -> 1)
Oct 16 22:17:31 astrid kernel: [3841192.960332] But ignored
Oct 16 22:17:31 astrid kernel: [3841193.233037] Setting FXO hook state 1
to (09), PolIgnore to (0)
<================Caller Answers===================================>
Oct 16 22:17:42 astrid kernel: [3841208.904764] 738782530 Polarity
Reversed (1 -> -1)
<================End Call==========================================>
Oct 16 22:17:52 astrid kernel: [3841222.734810] Setting FXO hook state 0
to (08), PolIgnore to (0)
Oct 16 22:17:52 astrid kernel: [3841222.734810] check hook; HOOK On, chan
2
<===============4 Line revesals to ensure hangup===================>
Oct 16 22:17:53 astrid kernel: [3841224.287608] 738785210 Polarity
Reversed (-1 -> 1)
Oct 16 22:17:54 astrid kernel: [3841225.713786] 738785470 Polarity
Reversed (1 -> -1)
Oct 16 22:17:56 astrid kernel: [3841228.723299] 738786010 Polarity
Reversed (-1 -> 1)
Oct 16 22:17:57 astrid kernel: [3841230.185637] 738786274 Polarity
Reversed (1 -> -1) 

Issue History 
Date Modified    Username       Field                    Change               
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2008-10-16 05:13 alecdavis      Note Added: 0093813                          
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