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From: mikel@berlioz.nsc.com (Michael G. Lohmeyer)
Subject: Re: Ethernet with higher data rates ?
Message-ID: <1991May7.221729.17399@berlioz.nsc.com>
Sender: news@berlioz.nsc.com
Organization: National Semiconductor Corporation
References: <heibe.673604290@forst>
Distribution: comp
Date: Tue, 7 May 1991 22:17:29 GMT

In article <heibe.673604290@forst> heibe@forst.informatik.rwth-aachen.de (Bernd Heinrichs) writes:
>Perhaps this is not a realizable idea. But I think in some environments it
>would make sense to use the existing Ethernet installations running with
>higher data, e.g. up to 100 Mbit/s, instead of the expensive FDDI.
>My problem is, that I do not know, if it is physically possible to run 50-
>or 75-ohm coaxial cables at such high data rates. Of course the cable
>length must be shortened and the minimum packet length has to exceed
>64 bytes.
>
>I would be very pleased when som people can tell me, such data rates are
>realizable or not.

     As was said in another posting in reply to the one above, the CSMA/CD 
protocols do not seem to lend well to 100 MBits/sec.  I don't know enough
about CSMA/CD to say one way or the other about that, but I do know that the
current ethernet IC's do not operate up to 100MBits/sec even if you
wanted them to.  So in order to make ethernet go faster, it would take
new chip designs to make it work.  All the current ICs for ethernet are 
based on 10MBit/sec, and hence, are not designed to work very far outside
that spec.

Mike
-------------
Mike Lohmeyer				mikel@berlioz.nsc.com
National Semiconductor Corporation
(408) 721-8075

