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Re: Slightly OT: Redundant CPE Switching for DS3

  • From: Jay Hennigan
  • Date: Thu Dec 22 15:01:43 2005

[email protected] wrote:

On Thu, Dec 22, 2005 at 12:21:55PM -0700, John Neiberger wrote:

I'm curious to find out if there is a device that would allow a single
DS3 to terminate on two different routers, and switch from the primary
to the backup router if the primary were to fail. I've seen this for
T1 circuits but I can't find anything for DS3.
I'd bet you could make something workable with a DPDT coaxial relay,
driving it from alarm contacts or a relay output of whatever
monitoring system you might already have. The tricky part would
probably be appropriately defining "failure" in order to get it to
automatically switch at the right time without causing more problems than you started with.
One probably could. More often than not it seems that the mechanism used to provide protection against hardware failure becomes more fragile than the hardware you're protecting. I've had far more issues caused by PIX failover going screwy than I've seen failed PIXen as a mild example.

Can the relay and associated hardware, cables, power supply and logic be guaranteed to be substantially more reliable than the router? If not, why bother?

Sometimes all of your eggs in one basket is the most sensible choice as long as you have a stainless steel basket.

Jay Hennigan - CCIE #7880 - Network Administration - [email protected]
NetLojix Communications, Inc. -
WestNet: Connecting you to the planet. 805 884-6323