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

[Andrew Kohlsmith]

On Friday 04 June 2004 15:02, Gary Franczyk wrote:
> 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.

http://lists.digium.com/pipermail/asterisk-users/2004-June/049407.html

> 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 times.

Middle of the night as in... around 4:40am or so?

> 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.

hardware RAID or software RAID, and is it IDE?

Processes which hold interrupts too long can cause this, and among those kinds 
of things is IDE block-master DMA.  I don't know if you can get away with 
reducing the PCI latency timer in the BIOS; linux usually overwrites these 
settings anyway, but you might have some luck.

Red Alarms aren't generated with high load, nor a latent PCI system; I would 
have the telco check out the lines (or have a T1 monitor installed to watch 
it for you while it's live) -- I think you've got bigger issues, but I don't 
think the Error 500s are related to the RAs.

-A.