[asterisk-users] Strange network issue

[Hans Witvliet]

On Fri, 2011-07-22 at 10:58 -0700, Dave Platt wrote:
> > They've got a bunch of Grandstreams that seem to be rock solid... until 
> > 7:00pm.  At 7:00, some of the phones become unavailable, and stay down.  Call 
> > quality is solid almost all the time.  But right at 7:00, things go bad.  Only 
> > some of the phone lines go down and they stay down until the phone is 
> > rebooted.
> > 
> > I'm not even sure what to look for when I go to the site.  Any ideas?
> 
> I'd look to see if there are any electrical circuits (lights,
> fans, etc.) which are on a timer of some sort, and are automatically
> powered off at 7 PM.
> 
> If somebody mistakenly plugged a piece of network kit into such a
> circuit, it would lose power at that time, and your network might
> end up being partitioned, or routing (switch or IP-level) might
> change abruptly.
> 

Hi,

Even if there is no equipment you own controlled by a timer, you still
can suffer from it.

Some power companies have different rates for power you use during
daytime or at night.
So even if _you_ don't have equipment on a timer, your neighbours might
have. Something like electrical boilers or so, or other "heavy
equipment". Switching them on/off can cause huge spikes on the
electrical wires.

A couple of neigbours at work have their own micro-power-generators.
About one in ten times, when they start delevering power to the grid,
all of our test-systems go down. Only the systems behind the
re-generated UPS (that removes spikes from the powerlines) are protected
against them.

So nasty litte spikes are harder to detect/tracedown than a full
blackout.

hw