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From: craig@bbn.com (Craig Partridge)
Newsgroups: comp.protocols.tcp-ip,comp.dcom.lans
Subject: Re: When is an ethernet full?
Message-ID: <56724@bbn.BBN.COM>
Date: 29 May 90 16:53:31 GMT
Article-I.D.: bbn.56724
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Reply-To: craig@ws6.nnsc.nsf.net.BBN.COM (Craig Partridge)
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> When is an ethernet full?  ....
> According to our Network General sniffer, 
> we constantly maintain about 10-15 percent utilization or (300 - 1000
> packets per second).   How much more traffic can this network support
> before performance falls off measurably?  Any ideas?  

The best place I know of to start answering this question is Boggs,
Mogul and Kent's article in Proc. of SIGCOMM '88 pp. 222-233.  The
gist of that article is that you can drive the Ethernet all the way
to its rated capacity assuming you are careful in the way you lay out
your network, and all your systems have good Ethernet hardware.

In practice of course, many of the systems won't have good Ethernet
hardware (for example, Jacobson's talk at SIGCOMM '88 indicated he'd
found an Ethernet chipset that could only go about 6 Mbits/sec).  So
you need to find some people out there with some good practical experience
about when some of their systems start breaking down, to figure out when
your network will die due to poor hardware/software.

Craig