Exchanges that matter...

Tim Salo salo at msc.edu
Thu Dec 5 15:43:18 UTC 1996


> Subject: Re: Exchanges that matter... 
> Date: Fri, 29 Nov 1996 11:02:24 -0800
> From: Paul A Vixie <paul at vix.com>
> 	[...]
> ... and they aren't subject to ATM's cell tax ...

I am surprised, (well, maybe not), that you aren't concerned about
the excessive overhead present in FDDI networks...

-tjs

From: salo at msc.edu (Tim Salo)
Date: Tue, 23 Jul 1996 14:50:11 -0500 (CDT)

> Date: Tue, 23 Jul 1996 14:28:27 -0400
> From: Paul Ferguson <pferguso at cisco.com>
> 	[...]
> Recall Jerry Scharf's numbers; they're indicative of the issue.
> 	[...]
> HDLC framing bytes =   3080633605		HDLC efficiency = 97.72
> ATM framing bytes =   3644304857		ATM efficiency = 82.61
> ATM w/snap framing bytes =   3862101043	ATM w/snap efficiency = 77.95

At a certain point, some of these arguments about ATM efficiency sound a bit
like saying FDDI is terrible because 4B/5B encoding is only 80% efficient.

I think a more interesting measure of the value of ATM versus other 
wide-area technologies is some sort of measure of throughput per dollar.






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