[asterisk-bugs] [Asterisk 0011875]: Default (sample setting) of channel group selection will cause glare on analog circuits

[noreply at bugs.digium.com]

The following issue has been ASSIGNED. 
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http://bugs.digium.com/view.php?id=11875 
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Reported By:                JimVanM
Assigned To:                qwell
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Project:                    Asterisk
Issue ID:                   11875
Category:                   Documentation
Reproducibility:            always
Severity:                   text
Priority:                   normal
Status:                     assigned
Asterisk Version:           1.4.17 
SVN Branch (only for SVN checkouts, not tarball releases): N/A 
SVN Revision (number only!):  
Disclaimer on File?:        N/A 
Request Review:              
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Date Submitted:             01-29-2008 19:49 CST
Last Modified:              01-30-2008 09:32 CST
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Summary:                    Default (sample setting) of channel group selection
will cause glare on analog circuits
Description: 
In the extensions.conf file, the example relating to channel groups should
not show 'g2'. but rather 'G2'.

Having outgoing channels select in the same order as incoming channels
will greatly increase the chances of glare occurring. Instead, selecting
highest-numbered channels in the pool for outgoing (the carrier usually
starts with lowest-number for incoming) will virtually eliminate the
chances of glare, except on very busy sites.

Let's say we have 8 analog lines. The default example suggests selecting
channels like this (g):

incoming-->1<-- outgoing
           2
           3
           4
           5
           6
           7
           8

To reduce the chance of glare, best practice (the default in any
traditional PBX) is to select highest-numbered lines for outgoing calls.
Like this (G):

incoming-->1
           2
           3
           4
           5
           6
           7
           8<-- outgoing

Not a big change, but it'll make a big difference to folks using analog
lines, who wouldn't tend to think about glare.

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---------------------------------------------------------------------- 
 svnbot - 01-30-08 09:32  
---------------------------------------------------------------------- 
Repository: asterisk
Revision: 101220

_U  trunk/
U   trunk/configs/extensions.conf.sample

------------------------------------------------------------------------
r101220 | qwell | 2008-01-30 09:32:37 -0600 (Wed, 30 Jan 2008) | 14 lines

Merged revisions 101219 via svnmerge from 
https://origsvn.digium.com/svn/asterisk/branches/1.4

(closes issue http://bugs.digium.com/view.php?id=11875)
........
r101219 | qwell | 2008-01-30 09:34:37 -0600 (Wed, 30 Jan 2008) | 5 lines

Change default config to use descending channel order of groups, rather
than ascending.
Fixes a potential source of confusion in glare-type situations.

Issue 11875, reported by JimVanM.

........

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http://svn.digium.com/view/asterisk?view=rev&revision=101220 

Issue History 
Date Modified   Username       Field                    Change               
====================================================================== 
01-30-08 09:32  svnbot         Checkin                                      
01-30-08 09:32  svnbot         Note Added: 0081425                          
01-30-08 09:32  svnbot         Status                   new => assigned     
01-30-08 09:32  svnbot         Assigned To               => qwell           
======================================================================