[asterisk-bugs] [Asterisk 0016755]: E1 PRI channel 'glare', where asterisk hangups up the inbound call from network.

[Asterisk Bug Tracker]

A NOTE has been added to this issue. 
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https://issues.asterisk.org/view.php?id=16755 
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Reported By:                alecdavis
Assigned To:                
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Project:                    Asterisk
Issue ID:                   16755
Category:                   Channels/chan_dahdi
Reproducibility:            random
Severity:                   minor
Priority:                   normal
Status:                     acknowledged
Asterisk Version:           SVN 
JIRA:                       SWP-842 
Regression:                 No 
Reviewboard Link:            
SVN Branch (only for SVN checkouts, not tarball releases): 1.6.1 
SVN Revision (number only!): 243988 
Request Review:              
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Date Submitted:             2010-02-02 13:24 CST
Last Modified:              2010-02-03 22:53 CST
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Summary:                    E1 PRI channel 'glare', where asterisk hangups up
the inbound call from network.
Description: 
randomly we are experiencing an ISDN 'glare'.

Captures caught so far have been our IVR dialing back out to the PSTN, at
exactly the same time an incoming network call arrives.

The issue is, asterisk hangs up on the inbound call from the network, that
has the channel set to exclusive, where the outbound call has only
requested a preferred channel, which later is assigned to another channel
in the SETUP ACKNOLEDGE.

Looks like we have outbound precedence in a 'glare' situation, when really
the inbound call is probably more important.
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 (0117689) alecdavis (manager) - 2010-02-03 22:53
 https://issues.asterisk.org/view.php?id=16755#c117689 
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Followed a call senario where the caller hangups first.<pre>
SWITCH                       ASTERISK
SETUP CR=1 CH=31       --->
     .... Normal setup ...
DISCONNECT CR=1 CH=31  --->
                       <---   RELEASE CR=1
                              insert mysql record.
                              (theory spend some time...)
RELEASECOMPLETE CR=1   --->

SETUP CR=2 CH=31       --->
                              CR2 not new call
                       <---   Channel not available
                              destroy previous call CR=1

Theory: Yet to catch one, but ready :)

The issue is, if the CDR recording takes too long, the switch sends a new
call with the same channel, but asterisk hasn't yet cleared down the
previous call internally, it will fail, as a call still exist on that
channel??? Well not really.

If the CDR was updated before the RELEASE was sent to the switch, then the
chances of missing (or processing out of order) the received RELEASE
COMPLETE and destory the channel may be minimised before the next SETUP
comes in.</pre> 

Issue History 
Date Modified    Username       Field                    Change               
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2010-02-03 22:53 alecdavis      Note Added: 0117689                          
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