Slightly OT: Redundant CPE Switching for DS3

Thu Dec 22 19:59:54 UTC 2005

will at loopfree.net 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 - jay at west.net
NetLojix Communications, Inc.  -  http://www.netlojix.com/
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