[asterisk-bugs] [DAHDI-linux 0014104]: [patch] Generate VMWI line reversal from FXS module to light LED on newer 'non intellegent phone'

[Asterisk Bug Tracker]

A NOTE has been added to this issue. 
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http://bugs.digium.com/view.php?id=14104 
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Reported By:                alecdavis
Assigned To:                dbailey
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Project:                    DAHDI-linux
Issue ID:                   14104
Category:                   wctdm
Reproducibility:            always
Severity:                   feature
Priority:                   normal
Status:                     assigned
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Date Submitted:             2008-12-18 02:36 CST
Last Modified:              2009-01-08 11:05 CST
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Summary:                    [patch] Generate VMWI line reversal from FXS module
to light LED on newer 'non intellegent phone'
Description: 
Added initial fundamental support to manipulate FXS line to generate
Message Waiting Indication. Still supports sending FSK as has been
supported for years.

Discovered undocumented parameter 'mwisendtype' in chan_dahdi.conf which
can only be 'rpas' Ring Pulse Alert Signal at the moment.

Intention is to use this field with parameters as follows;
   'fsk' or undefined for exisiting FSK only support.
   'none' no FSK spill heard every second time you go off hook.
   'rpas' for existing support ring pulse before FSK
   'lrev' line reversed while messages exist
   'hvdc' high voltage, 90Vdc idle voltage
   'hvac' high voltage neon generation, Following Silicb AN33

Alec


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 (0097208) dbailey (administrator) - 2009-01-08 11:05
 http://bugs.digium.com/view.php?id=14104#c97208 
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I had not really thought through the situation where there could be
multiple
line reversal situations.  It certainly could be a problem though I have a
hard
time thinking that a phone would be configured for line reversal MWI and
use
line reversal alert signaling for Caller ID.

If the for some reason someone wanted this situation, what would occur
when a
message is already pending and a line reversal alert is requested?  I
would assume
that the event of the line reversal transition is what is actually desired
for the alert signal. 
Therefore I would implement it so that the polarity would transition back
to nominal polarity in
this situation.  (An exclusive Or'ing of all the conditions.) 

Or do we just say you can't do that and say the two modes are
incompatible. 

Issue History 
Date Modified    Username       Field                    Change               
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2009-01-08 11:05 dbailey        Note Added: 0097208                          
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