[asterisk-bugs] [LibPRI 0016909]: [patch] pritimer's in chan_dahdi.conf not honoured

[Asterisk Bug Tracker]

A NOTE has been added to this issue. 
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https://issues.asterisk.org/view.php?id=16909 
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Reported By:                alecdavis
Assigned To:                
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Project:                    LibPRI
Issue ID:                   16909
Category:                   Channels/chan_dahdi
Reproducibility:            always
Severity:                   minor
Priority:                   normal
Status:                     new
Asterisk Version:           SVN 
JIRA:                        
SVN Branch (only for SVN checkouts, not tarball releases): 1.6.1 
SVN Revision (number only!): 248954 
Disclaimer on File?:        N/A 
Request Review:              
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Date Submitted:             2010-02-26 02:53 CST
Last Modified:              2010-03-01 20:58 CST
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Summary:                    [patch] pritimer's in chan_dahdi.conf not honoured
Description: 
configuring pritimer=>k,3 in chan_dahdi.conf is overwritten by libpri's
pri_default_timers, which defaults 'k' timer back to 7.

required to prevent pri lockups under heavy conditions where switch
doesn't like so many unacknowledge i-frames.
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Relationships       ID      Summary
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related to          0002518 Provide configurable timers for PRI's
related to          0016790 [patch] !! Got reject for frame 41, ret...
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 (0118734) alecdavis (manager) - 2010-03-01 20:58
 https://issues.asterisk.org/view.php?id=16909#c118734 
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clarification from Q.921:
Although the default is 1 for BRI, it doesn't stipulate that it's the
maximum, but I agree, better to be safe than sorry, although it does say
'shall not exceed 127'.

5.9.5 Maximum number of outstanding I frames (k)
The maximum number (k) of sequentially numbered I frames that may be
outstanding (that is,
unacknowledged) at any given time is a system parameter which shall not
exceed 127, for extended
(modulo 128) operation.
– For an SAP supporting basic access (16 kbit/s) signalling, the default
value shall be 1.
– For an SAP supporting primary rate (64 kbit/s) signalling, the default
value shall be 7.
– For an SAP supporting basic access (16 kbit/s) packet information, the
default value shall
be 3.
– For an SAP supporting primary rate (64 kbit/s) packet information, the
default value shall be
7.
NOTE – In certain digital sections (e.g. involving satellites), for the
64 kbit/s D-channel, the value of k may
not be large enough to assure efficient operation. To accommodate such
configurations, it is recommended
that user and network equipment allow selection of alternative values of
k, or implement the data link layer
parameter negotiation procedures of Appendix IV. 

Issue History 
Date Modified    Username       Field                    Change               
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2010-03-01 20:58 alecdavis      Note Added: 0118734                          
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