[asterisk-bugs] [Asterisk 0018395]: C should not receive request call again after C cancel if B blind transfer using atxfer call C

Asterisk Bug Tracker noreply at bugs.digium.com
Tue Jan 18 12:04:44 CST 2011


A NOTE has been added to this issue. 
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https://issues.asterisk.org/view.php?id=18395 
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Reported By:                shihchuan
Assigned To:                rmudgett
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Project:                    Asterisk
Issue ID:                   18395
Category:                   Features
Reproducibility:            always
Severity:                   major
Priority:                   normal
Status:                     assigned
Asterisk Version:           1.8.0 
JIRA:                        
Regression:                 No 
Reviewboard Link:            
SVN Branch (only for SVN checkouts, not tarball releases): N/A 
SVN Revision (number only!):  
Request Review:              
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Date Submitted:             2010-11-29 04:31 CST
Last Modified:              2011-01-18 12:04 CST
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Summary:                    C should not receive request call again after C
cancel if B blind transfer using atxfer call C
Description: 
call limit of B is 2
1. A call B, B answered
2. B *97(atxfer) call C, C rining (no aswer)
3. B hangup 
4. C cancel 
5. B receive request call (It's ok)

call limit of B is 1
1. A call B, B answered
2. B *97(atxfer) call C, C rining (no aswer)
3. B hangup 
4. C cancel call
5. C receive request call again, C ringing (behavior isn't reasonable)
6. C cancel call again 
7. C receive request call again, C ringing (behavior isn't reasonable)

Because B reached call limit, C receive request call again.
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Relationships       ID      Summary
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related to          0017273 atxfer *2 channel dahdi FXS no hangup
related to          0017999 Issues with DTMF triggered attended tra...
====================================================================== 

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 (0130621) svnbot (reporter) - 2011-01-18 12:04
 https://issues.asterisk.org/view.php?id=18395#c130621 
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Repository: asterisk
Revision: 302172

U   branches/1.4/res/res_features.c

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r302172 | rmudgett | 2011-01-18 12:04:37 -0600 (Tue, 18 Jan 2011) | 88
lines

Issues with DTMF triggered attended transfers.

Issue https://issues.asterisk.org/view.php?id=17999
1) A calls B. B answers.
2) B using DTMF dial *2 (code in features.conf for attended transfer).
3) A hears MOH. B dial number C
4) C ringing. A hears MOH.
5) B hangup. A still hears MOH. C ringing.
6) A hangup. C still ringing until "atxfernoanswertimeout" expires.
For v1.4 C will ring forever until C answers the dead line. (Issue
https://issues.asterisk.org/view.php?id=17096)

Problem: When A and B hangup, C is still ringing.

Issue https://issues.asterisk.org/view.php?id=18395
SIP call limit of B is 1
1. A call B, B answered
2. B *2(atxfer) call C
3. B hangup, C ringing
4. Timeout waiting for C to answer
5. Recall to B fails because B has reached its call limit.

Because B reached its call limit, it cannot do anything until the transfer
it started completes.

Issue https://issues.asterisk.org/view.php?id=17273
Same scenario as issue 18395 but party B is an FXS port.  Party B cannot
do anything until the transfer it started completes.  If B goes back off
hook before C answers, B hears ringback instead of the expected dialtone.

**********
Note for the issue https://issues.asterisk.org/view.php?id=17273 and
https://issues.asterisk.org/view.php?id=18395 fix:

DTMF attended transfer works within the channel bridge.  Unfortunately,
when either party A or B in the channel bridge hangs up, that channel is
not completely hung up until the transfer completes.  This is a real
problem depending upon the channel technology involved.

For chan_dahdi, the channel is crippled until the hangup is complete.
Either the channel is not useable (analog) or the protocol disconnect
messages are held up (PRI/BRI/SS7) and the media is not released.

For chan_sip, a call limit of one is going to block that endpoint from any
further calls until the hangup is complete.

For party A this is a minor problem.  The party A channel will only be in
this condition while party B is dialing and when party B and C are
conferring.  The conversation between party B and C is expected to be a
short one.  Party B is either asking a question of party C or announcing
party A.  Also party A does not have much incentive to hangup at this
point.

For party B this can be a major problem during a blonde transfer.  (A
blonde transfer is our term for an attended transfer that is converted
into a blind transfer.  :)) Party B could be the operator.  When party B
hangs up, he assumes that he is out of the original call entirely.  The
party B channel will be in this condition while party C is ringing, while
attempting to recall party B, and while waiting between call attempts.

WARNING:
The ATXFER_NULL_TECH conditional is a hack to fix the problem.  It will
replace the party B channel technology with a NULL channel driver to
complete hanging up the party B channel technology.  The consequences of
this code is that the 'h' extension will not be able to access any channel
technology specific information like SIP statistics for the call.

ATXFER_NULL_TECH is not defined by default.
**********

(closes issue https://issues.asterisk.org/view.php?id=17999)
Reported by: iskatel
Tested by: rmudgett
JIRA SWP-2246

(closes issue https://issues.asterisk.org/view.php?id=17096)
Reported by: gelo
Tested by: rmudgett
JIRA SWP-1192

(closes issue https://issues.asterisk.org/view.php?id=18395)
Reported by: shihchuan
Tested by: rmudgett

(closes issue https://issues.asterisk.org/view.php?id=17273)
Reported by: grecco
Tested by: rmudgett

Review: https://reviewboard.asterisk.org/r/1047/

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http://svn.digium.com/view/asterisk?view=rev&revision=302172 

Issue History 
Date Modified    Username       Field                    Change               
====================================================================== 
2011-01-18 12:04 svnbot         Checkin                                      
2011-01-18 12:04 svnbot         Note Added: 0130621                          
======================================================================




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