MCI [ATM overhead]

Thu Mar 21 08:48:40 UTC 1996

> From: salo at msc.edu (Tim Salo)
> > From: Wolfgang Henke <wolfgang at whnet.com>
> > SONET (Synchronous Optical Network) speeds given in Mbps
> >
> >                 nominal   w/o Sonet  ATM   TCP/IP
> >                           overhead
> >
> > OC-3   STS-3c   155.520     149      122     137   future net backbone
> > 	[...]
>
> I think your 122 Mbps "ATM" number could be a bit confusing, even knowing
> the assumptions you described in earlier mail.  (Also, more bandwidth seems
> to be available to "TCP/IP" than appears to be available from ATM...)
>
I believe that the number is for TCP/IP carrying capacity _without_ ATM.

> One could remove the ATM overhead, but then one has a point-to-point
> link, rather than a link over which data from many sources can be
> multiplexed.
>
Rather, that leaves us with the excellent (very desirable) option of a
link where data from many sources are multiplexed by TCP/IP....

I do not see what ATM buys in this situation.

WSimpson at UMich.edu
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BSimpson at MorningStar.com
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