Path: utzoo!utgpu!news-server.csri.toronto.edu!rutgers!apple!agate!ucbvax!INRIA.INRIA.FR!Yves.Devillers
From: Yves.Devillers@INRIA.INRIA.FR (Yves Devillers)
Newsgroups: comp.protocols.tcp-ip
Subject: Re: When is a link saturated?
Message-ID: <9101160118.AA11954@inria.inria.fr>
Date: 16 Jan 91 01:18:19 GMT
References: <9101160029.AA09554@inria.inria.fr>
Sender: daemon@ucbvax.BERKELEY.EDU
Organization: The Internet
Lines: 37


 In your previous mail you wrote:

   	Tsui noted that priority queuing is especially useful in international
   	networks, where bandwidth is often most expensive.

   Wow!  That is a new one on me.  Can someone explain how ordering
   packets (but not discarding) can save bandwidth?  Assuming that
   the number of retransmissions aren't influenced, but merely that
   interactive applications observe smaller round-trip times, the
   total throughput should be the same...

   I must be missing something obvious.  Can someone enlighten me
   (and possibly others)?

-->aren't you missing the fact that when interactive users get poor reactions
they complain about the network being overloaded but don't get satisfied
(satisfaction being higher bandwidth to allow better interactions) since
those lines are so expensive that noone has money for them

On the other side giving better priority to interactive traffic ("re-ordering")
makes:
1- interactive users happy (better responsiveness)
2- network manager happy (no extra penny spent)
3- bulk traffic ftp fans unhappy

The total throughput is *globally* the same, not *individually* :-)

 Yves

 ----------------------------------------------------------------
 Yves Devillers
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