From owner-freebsd-hackers  Sat May 25 11:49:39 1996
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Date: Sat, 25 May 1996 11:48:34 -0700
From: Andrew McRae <amcrae@cisco.com>
Message-Id: <199605251848.LAA08805@doberman.cisco.com>
To: dennis@etinc.com
Subject: Re: The view from here (was Re: ISDN Compression Load on CPU)
Cc: hackers@freebsd.org
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>As for hot swap, we've been selling cards for 8 years and i can
>count on one hand the number of boards that died in a box in
>the first 3 years in the field . Virtually all of the failures are some
>lightning
>event that trashed an unprotected machine or some banana
>pulling the card out while it was on (perhaps hoping for "hot
>swap"). It just doesnt happen enough to justify the price, unless
>your cards are flakey or run too hot.

By far and away the reason that cards are hot swapped in
cisco boxes is because configuration changes can
occur frequently in some environments, new interfaces are
added, interfaces are moved to new or existing boxes etc.
Imagine an ISP who, everytime a new customer came online, had
to shutdown his router to install new line cards; some do, but
a lot prefer to maintain high uptime.
It is fairly rare to hot swap cards because of failure.

cheer,
AMc