[asterisk-bugs] [Asterisk 0016010]: Call abort after wrong behaviour of VNAK transmission

[Asterisk Bug Tracker]

A NOTE has been added to this issue. 
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https://issues.asterisk.org/view.php?id=16010 
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Reported By:                ffloimair
Assigned To:                
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Project:                    Asterisk
Issue ID:                   16010
Category:                   Channels/chan_iax2
Reproducibility:            sometimes
Severity:                   major
Priority:                   normal
Status:                     acknowledged
Asterisk Version:           1.4.26.2 
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:             2009-10-02 03:22 CDT
Last Modified:              2009-10-27 04:39 CDT
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Summary:                    Call abort after wrong behaviour of VNAK
transmission
Description: 
Asterisk sends VNAK to signal a retransmission of a packet. After
retransmission the request is sent again and again... Abort of the call is
the result after a few retries.
Overall, asterisk very often sends VNAK after receiving LAGRQ and PING
consecutively. Why does asterisk know that packet 2 after 1 is missing if
there was no packet 3 so far (numbers referring to ascending sequence
numbers in IAX Header)? This is confusing since the RFC states the below
text requiring to retransmit all frames with a higher sequence number than
the one received with the VNAK.

Please see the attached pcap file.

There was no significant output in the asterisk console, so I do not post
this as of now. If required I can post this later.

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Relationships       ID      Summary
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duplicate of        0016055 Loss of IAX calls after strange VNAK be...
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 (0112796) tkarl (reporter) - 2009-10-27 04:39
 https://issues.asterisk.org/view.php?id=16010#c112796 
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I think I have the same problem in one of my projects in Spain, where I
have an IAX trunk set up.
The asterisk drops all conversations to this trunk after some time with
the verbose notice "Max retries exceeded to host...". 
It seem like this is happening more often when I have multiple
conversations at the same time. When I set up only 2 or 3 conversation I
have to keep those conversations for hours to reproduce this problem. When
I have more than 16 conversations it is very likely that the problem occurs
after a few minutes.
After sniffing the network traffic, I recognized that before the error
message is printed, more VNAKs are present so I found the issue and saw the
same wrong VNAK behavior.
I don’t think it is necessary to provide my Wireshark trace at this
point of time; if you need any more information I will do my best to
provide all required data.
Unfortunately my customer is getting a little bit nervous so it would be
great to have a time schedule of when this issue will be processed. Thanks
a lot. 

Issue History 
Date Modified    Username       Field                    Change               
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2009-10-27 04:39 tkarl          Note Added: 0112796                          
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