[Asterisk-Users] Problem with T1 PRI line resetting/dropping calls.

Gary Franczyk gary at de-scribe.com
Fri Jun 4 12:02:03 MST 2004

I searched the archives and nothing seemed to fit the problem.  Most of the
posts I have found say what you said... "this was just discussed", but I
cannot find any good information about the actual discussion.  If you can
send a link to the thread you are talking about, I will check it out.

It is unlikely that it is a load issue.  This sometimes happens in the
middle of the night when there is almost no one using the system.  I haven't
seen a real corelation between the dropped calls and system load.  It does
nothing else.  Not even backups.  The T1 reset seems to come at random

The system only accepts incoming calls... usually only during business
hours, with heavier load during the afternoon.   The disks system is a two
disk raid-1 mirror.

I started a vmstat 1 to file... but I don't know if I have enough disk space
to keep that much output around.  I will try.

-----Original Message-----
From: asterisk-users-admin at lists.digium.com
[mailto:asterisk-users-admin at lists.digium.com]On Behalf Of Andrew
Sent: Friday, June 04, 2004 1:52 PM
To: asterisk-users at lists.digium.com
Subject: Re: [Asterisk-Users] Problem with T1 PRI line
resetting/dropping calls.

On Friday 04 June 2004 13:09, Gary Franczyk wrote:
> I am having a serious problem with my Asterisk system.  Every few days, my
> PRI line resets and drops all calls.  I get these errors in the messages
> log:
> Jun  3 02:41:11 WARNING[11276]: PRI: Read on 39 failed: Unknown error 500

This has been discussed very recently; you might want to check the list
archives.  From what I remember someone is pinning it down to system (CPU?)
load -- error 500 being when the FIFO in the cap card is empty and has no
audio to send.

Is your system doing anything else other than running *?  How many channels?
What's the call *setup* volume like?  (i.e. quiet and then 50 calls get made
at once type of thing)  What is the disk subsystem?

Run 'vmstat -n 1' for a couple hours when the call drops are likely to occur
and log the output somewhere.  Hell, run vmstat -n 1 and leave it spewing to
a log file somewhere and when the calls drop correlate the last few seconds'
worth of this file to the drop and post it...

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