Path: chuka.playstation.co.uk!scea!greg_labrec@interactive.sony.com
From: Charles Henrich <henrich@msu.edu>
Newsgroups: scea.yaroze.freetalk
Subject: Re: Audio breakup in the auditorium
Date: Sat, 30 Aug 1997 12:57:01 -0400
Organization: SCEA News Server
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Wayne K. Werner wrote:

> MS defaults to 1500 bytes for MTU and 8KB for the rwin.  These values
> severly hamper internet access thru a modem.  The "natural" size of an
> internet MTU is 576 bytes.  40 bytes of this packet is header info, leaving
> 536 for data.  The rwin should be a multiple of 536.

There is no such thing as a "natural" internet packet, in fact you will 
find the vast majority of any bulk data transfers are always 1500, to
limit the header overhead associated with each packet. 
> 
> You will be astounded at how much faster your downloads are, with no
> changes in ISP or modem speed.  I have been using these settings for a
> month or so now, and I have been experiencing great audio quality in the
> auditorium.  I do get some breakup, but mostly I get clear, coherent audio.

Im curious as to how you measure this, downloads should be *slower* with
a
smaller MTU.  When you decrease the MTU size, you are adding extra bytes
you must both send and receive (ack for each packet, as well as header
data in each received packet, increasing the overall data stream size.)

What shrinking the MTU size WILL do for you is make interactive response
during high bandwidth usage feel better.  Your keypresses get more
chances
at being sent off when your system is generating a new packet more
frequently
than at 1500.  However download/upload times will suffer..  It may be
that
placeware is doing all sorts of little transmissions during a
presentation,
and as they queue up behind large data load, it gets nasty.  Then again
maybe Windows networking sucks for beans, and it doesnt deal with 
large packet sizes well.

-Crh

       Charles Henrich     Michigan State University     henrich@msu.edu

                         http://pilot.msu.edu/~henrich