[asterisk-bugs] [Asterisk 0014692]: [patch] ISDN-Transfer causes backcall attempt of attendent phone

[Asterisk Bug Tracker]

A NOTE has been added to this issue. 
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https://issues.asterisk.org/view.php?id=14692 
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Reported By:                sodom
Assigned To:                rmudgett
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Project:                    Asterisk
Issue ID:                   14692
Category:                   Channels/chan_misdn
Reproducibility:            always
Severity:                   major
Priority:                   normal
Status:                     assigned
Asterisk Version:           1.4.24 
Regression:                 No 
SVN Branch (only for SVN checkouts, not tarball releases): N/A 
SVN Revision (number only!):  
Request Review:              
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Date Submitted:             2009-03-18 07:57 CDT
Last Modified:              2009-07-10 19:09 CDT
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Summary:                    [patch] ISDN-Transfer causes backcall attempt of
attendent phone
Description: 
If you successfuly transfer a call via ISDN-Transfer the attendant phone
will generate a "ghost" back call for the first phone you spoke to.

e.g.

You got three phones with the number 11 (port 4),15 (port 8) and 13 (port
6).

15 calls 11 -> connection success.
15 presses R-Key -> Hold success, 11 got moh
15 calls 13 -> connection success.
15 simply hook on -> transfer 13->11 success
15 starts ringing again, indicating still established call to 11

as there is nothing left from the connection 15->11 you can run into real
problems. Some phones ring forether as they don't reaslise that the
connection was disconnected. (Most of Siemens DECT-ISDN phones e.g., on
some you can't get rid of the ghost call other the switching the phone
off.)

I analised the problem down and i think it's simply the problem that
asterisk didn't send a ISDN-Relase message for the first connection. It
only send a ISDN-Release message for the second connection, so the
attendant phone simply didn't know that the initial connection was also
released.

I attached a asterisk CLI of the misdn debug lv. 1.

I guess the problem is that asterisk masquerades the second connection
with the first connection. Logicaly only three connection are handling in
asterisk but in real you would need to handle four connections.
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---------------------------------------------------------------------- 
 (0107606) rmudgett (administrator) - 2009-07-10 19:09
 https://issues.asterisk.org/view.php?id=14692#c107606 
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There are several outstanding problems with the chan_misdn transfer feature
that individual fixes would conflict with each other.  Therefore, the
misdn_xfer_v14_r205839.patch file fixes the following issues:

JIRA ABE-1903 - Orphaned held calls left in music-on-hold.
issue https://issues.asterisk.org/view.php?id=14692 - Held calls are not
automatically cleared after transfer.
issue https://issues.asterisk.org/view.php?id=14355 - Crash if attempt to
transfer a call to an application. 

Issue History 
Date Modified    Username       Field                    Change               
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2009-07-10 19:09 rmudgett       Note Added: 0107606                          
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