[asterisk-bugs] [DAHDI-linux 0009096]: [patch] DTMF CID without polarity reversal implementation in wctdm for Denmark, Brazil, etc

[Asterisk Bug Tracker]

A NOTE has been added to this issue. 
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https://issues.asterisk.org/view.php?id=9096 
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Reported By:                fleed
Assigned To:                sruffell
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Project:                    DAHDI-linux
Issue ID:                   9096
Category:                   NewFeature
Reproducibility:            always
Severity:                   minor
Priority:                   normal
Status:                     ready for testing
Target Version:             2.2.0
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Date Submitted:             2007-02-18 19:02 CST
Last Modified:              2009-08-31 09:26 CDT
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Summary:                    [patch] DTMF CID without polarity reversal
implementation in wctdm for Denmark, Brazil, etc
Description: 
Caller id signaling in Denmark, Brazil and other places is done through
DTMF tones before the first ring, without polarity reversal to indicate the
start of incoming data. Currently wctdm can only detect dtmf callerid if
there is a polarity reversal before the dtmf digits, so it's not working in
some countries.

This uses the idea reported in bug id 9 for wcfxo, but implements it in
wctdm. It fakes a polarity reversal so that the code already in chan_zap
can take that and pass it through the dtmf bit.

To use, patch and build the zaptel part, load the module with option
dtmf=1. Then use the following in zapata.conf:
callerid=asreceived
usecallerid=yes
cidsignalling=dtmf
hidecallerid=no
cidstart=polarity

Works fine in Brazil, on a Telemar line.

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Relationships       ID      Summary
----------------------------------------------------------------------
related to          0000009 [patch] DTMF CLIP not supported by Aste...
related to          0012658 [patch] DTMF issues on Zap
related to          0009201 Problem with caller ID detection when D...
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 (0109850) dbailey (administrator) - 2009-08-31 09:26
 https://issues.asterisk.org/view.php?id=9096#c109850 
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dditions to chan_dahdi.conf in order to use the 9690_chan_dahdi-trunk
patch

; causes monitor loop to look for dtmf energy on the incoming channel to
initate
; cid acquisition
cidstart=dtmf

; The energy level used to trigger dtmf cid acquisition.   This number is
; compared to the average over a packet of audio of the absolute values of
16
; bit signed linear samples. The default is set to 256.  The choice of 256
is
; arbitrary.  The value you should select should be high enough to prevent
false
; detections while low enough to insure that no dtmf spills are missed.

dtmfcidlevel=256 

Issue History 
Date Modified    Username       Field                    Change               
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2009-08-31 09:26 dbailey        Note Added: 0109850                          
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