Path: utzoo!utgpu!water!watmath!clyde!att!pacbell!lll-tis!helios.ee.lbl.gov!nosc!tetra!budden
From: budden@tetra.NOSC.MIL (Rex A. Buddenberg)
Newsgroups: comp.protocols.tcp-ip
Subject: Friendliness vs performance
Message-ID: <697@tetra.NOSC.MIL>
Date: 25 Aug 88 00:58:46 GMT
References: <8808232225.AA05793@ucbvax.Berkeley.EDU>
Reply-To: budden@tetra.nosc.mil.UUCP (Rex A. Buddenberg)
Organization: USCG Headquarters, Washington DC
Lines: 34

For Dave Crocker.

I would recast the question more in terms of capacity/throughput
traded off against robustness/fault tolerance/survivability.  Fair?

Most users tend to underestimate the real fault tolerance needs.
Once a network is put in place, it attracts applications like ants
to a picnic.  Before you can spell TCP/IP, the network has become
so critical that it's failure becomes intolerable.  I'm familiar
with a few horror stories like one about a bank that lost its 
funds transfer net for several hours.  The interest charges on the
cash it had to borrow to keep afloat ranged into 8 figures.

I have three very clear requirements where workstations and sensors
on a LAN is clearly the best way to go.  In all three cases, network
loading is very modest -- one ridiculously so: in terms of dozens
of bytes per day [!!].  But fault tolerance -- immunity against either
damage or component failure -- is vital to all three.

The curious technological development is that in the LAN world,
this isn't a trade off.  The only fault tolerant LAN architecture
out there readily available is doubly linked rings.  Discounting
Proteon's proprietary products, this leaves FDDI -- somewhat
higher performance than ether...

Fault tolerance is a lot like paychecks -- most of us rather take
them for granted.  They come every couple weeks -- especially for
us folks whose paychecks are provided by the taxpayers.  And like
LAN service -- expected to be there when we want to use it.  Watch
the fracas when your taken for granted paycheck or LAN fails.
I'd suggest a caveat for a vendor: fault tolerance may not gain
you lots of customers, but lack of it can lose a bunch.

Rex Buddenberg