nanog mailing list archives

Re: Greener grass on the other side of the fence


From: David Lesher <wb8foz () nrk com>
Date: Mon, 29 Jun 1998 08:33:08 -0400 (EDT)


I'm not sure the telephone network is really that robust.  Think about
the SS7 network and a world with 50,000 CLEC's.  Like most things, you
don't want to really know what's in the sausage.  Some systems are designed
with a high degree of control, so everything works correctly.  But they
often have the property of catastrophic failure when any part fails to
work perfectly, such as the cascading failures of the western power grid
last year.

Years ago, it WAS that robust. Virtually not central control. The
switches were internally redundant [axe off part of a #1 crossbar
switch; like a worm the rest keeps wiggling...], trunking was
almost too simple to break in increments greater than one, etc.

But we've traded dumb redundancy for speed and efficiency. And
we've paid for that. It struck me that the Martin Luther King Day
ATT voice crash [?1991?] was chillingly parallel to this year's
frame outage -- both went down on DoS from Sorcerer's Apprentice
worth of maintenance messages.



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Unless the host (that isn't close).........................pob 1433
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