[asterisk-bugs] [DAHDI-linux 0015268]: REJ S frame not handled properly

[Asterisk Bug Tracker]

The following issue has been UPDATED. 
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https://issues.asterisk.org/view.php?id=15268 
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Reported By:                tjardick
Assigned To:                sruffell
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Project:                    DAHDI-linux
Issue ID:                   15268
Category:                   wct4xxp
Reproducibility:            always
Severity:                   major
Priority:                   normal
Status:                     assigned
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Date Submitted:             2009-06-04 05:17 CDT
Last Modified:              2009-08-25 18:05 CDT
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Summary:                    REJ S frame not handled properly
Description: 
Production on a 4 port E1 card starts and after about 30 minutes we start
to have problems of receiving cause 34 Circuit or channel unavailable.
 
When analysing the wireshark tracing on the D-channel and looking at the
moment the problems starts, we see the following L2 (LAPD) issue:
 
-          The asterisk sometimes does not retransmit I frames after
receiving a REJ S frame.
-          The network expects retransmission and in the meanwhile
continues to send regular RR S frames with the same R counter
-          The asterisk – nicely - doesn’t send more  than the allowed
7 unacknowledged I frames
-          The asterisk – less nicely - then starts repeating the 7th
one regularly.
-          If the network resends a REJ S frame, retransmission occurs
correctly.
 
As the REJ frame was not handled correctly – or could just have been
lost – wouldn’t it be smarter to retransmit the first unacknowledged I
frame instead of the last one ?  That behavior should meet the expectation
of the network even if the REJ frame was not received or handled.
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Issue History 
Date Modified    Username       Field                    Change               
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2009-08-25 18:05 tilghman       Category                 Channels/chan_dahdi =>
wct4xxp
2009-08-25 18:05 tilghman       version                  1.4.24 =>           
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