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From: prindevi@INRIA.INRIA.FR (Philippe-Andre Prindeville)
Newsgroups: comp.protocols.tcp-ip
Subject: Re:  When is a link saturated?
Message-ID: <9101141440.AA18866@inria.inria.fr>
Date: 14 Jan 91 14:40:24 GMT
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I don't think you can simplify the question to this extent.  It
depends on how bursty the traffic patterns are, and what sort
of best/worst/mean case service you want to provide.  The phone
companies use two numbers, for instance, 80% and 95% of the
service expected (or provided).  For instance, they try to
engineer the networks so that levels of quality for 80% and
95% of the calls-placed, packets routed, or whatever exhibit
a certain level of quality.

For datagram traffic, if you look at Delay vs. Throughput on
a graph, you will see that for a linear increase is Throughput,
you start to see much greater increases in Delay.  This might
not be acceptable for interactive uses.

Look at the famous "DEC-bit" paper by Raj Jain, DEC-TR-508
(if memory serves).  It is available upon request from DEC.
Don't send me mail asking how to get it.

-Philip