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From: rpw3@fortune.UUCP
Newsgroups: net.lan
Subject: Re: IEEE802/Ethernet lossage - (nf)
Message-ID: <3289@fortune.UUCP>
Date: Fri, 11-May-84 23:08:18 EDT
Article-I.D.: fortune.3289
Posted: Fri May 11 23:08:18 1984
Date-Received: Sun, 13-May-84 08:43:49 EDT
Sender: notes@fortune.UUCP
Organization: Fortune Systems, Redwood City, CA
Lines: 25

#R:mit-eddi:-177900:fortune:5900020:000:920
fortune!rpw3    May 11 18:30:00 1984

I posted a fairly long article about this 802.3 vs. Ethernet thing a
while back, but the key is that none of the (currently) Xerox-registered
Ethernet frame types (such as XNS or IP/TCP) are legal values for the
length field. So, 802.3-only boards won't receive data from Ethernet-only
software, but they can share the cable (if you don't mind each XNS or IP
packet potentially bumping an "invalid length field" error count in the
802.3 system). But sophisticated Ethernet systems will be able to talk
to 802.3 systems (both ways) by treating each possible value of the 802.3
length field (46 to 1518) as a valid sub-type of the 802.3 "type".

Ugly, but then again sometimes it's good to remember:

	"Politics is the art of the possible."

;-}

Rob Warnock

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