North American Network Operators Group
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Re: Why do we use facilities with EPO's?

  • From: Warren Kumari
  • Date: Wed Jul 25 18:32:01 2007


On Jul 25, 2007, at 3:35 PM, Patrick W. Gilmore wrote:


On Jul 25, 2007, at 2:03 PM, Tuc at T-B-O-H.NET wrote:

If they can be avoided, why do we put up with them? Do we really
want our colo in downtown San Francisco bad enough to take the risk
of having a single point of failure? How can we, as engineers, ask
questions about how many generators, how much fuel, and yet take
for granted that there is one button on the wall that makes it all
turn off? Is it simply that having colo in the middle of the city
is so convenient that it overrides the increased cost and the reduced
redundancy that are necessitated by that location?

You forgot the default "Single Point of Failure" in anything..

HUMANS.

The earth is a SPoF. Let's put DCs on the moon.

Besides, safety always overrides convenience. And I don't think that is a bad trade off.

Me neither...

Having multiple redundant sites (and a well designed network between them) is almost always going to be better than a single, wildly redundant site. No matter how much redundancy you build into a single site, you cannot (realistically) engineer away things like floods, etc. Planning your redundancy and testing it though is very important...

Random anecdote (from a friend, I don't know if it true or not):
Back in the day (before cheap international circuits), a very large financial in New York needed connectivity to some branches in Europe, so they bought some capacity on a satellite transponder and built their own ground-station (not cheap) fairly close to NY. They then realized that the needed a redundant ground station in case the first one failed or something similar, so the built a second ground- station, just outside Jersey City....

One of the satellite connectivity failure modes is... rain fade.....

W



--
TTFN,
patrick



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