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From: sunny@sun.uucp (Sunny Kirsten)
Newsgroups: net.lan
Subject: Re: cheapernet?
Message-ID: <1259@sun.uucp>
Date: Wed, 13-Jun-84 02:40:18 EDT
Article-I.D.: sun.1259
Posted: Wed Jun 13 02:40:18 1984
Date-Received: Thu, 14-Jun-84 00:44:47 EDT
References: <4725@amd70.UUCP>
Organization: Sun Microsystems, Inc.
Lines: 40

Greetings, fans of cheapernet:

	*A* form of cheapernet is espoused quite successfully by 3Com.
Wheras Ethernet is your big half inch inflexible expensive cable conceived in
the early days of Xerox' Ethernet (back in the 3MHz days, remember?), where
the idea was to pre-wire a building with the cable, and provide transceivers
built into the wall, so that each office would have a couple "information
outlets", the now Dec-Intel-Xerox standard transceiver/controller interface,
Cheapernet is composed of thinner, cheaper flexible cable (RG-58/AU), and the
concept of building Ethernet transceivers (cheaper smaller VLSI ones) into
equipment (a la 3Com's IE for the *ugh* IBM PC) so that no one has to pay
big bucks for "real" transceivers.  If this is done correctly, as by 3Com,
there is direct plug compatibility with "real" Ethernet.  Typically, in this
world, connectors are BNC rather than the traditional Ethernet connectors.
The only drawback of this situation, is that the thinner Ether is more "lossy",
so that you can only go half the distance of cable before you need a repeater.
If you're interested in 3Com's cheapernet, contact them at (415)961-9602,
POB7390, Mtn. View, CA 94039.  Tell 'em Sunny sent ya'.

	Another form of cheaper net (cheapernet *might* be trademarked?)
is to drop the operational frequency down from 10Mhz to around 1Mhz, go
INcompatible with "real" ethernet (bad idea) and get your cost down with
cheaper lower frequency transceivers, maybe also cost reduction with VLSI.

	What do I think of cheapernet?  If it's compatible with "real"
Ethernet, as 3Com's is, I think it's better than Ethernet, and I expect this
new standard (cheap thin flexible cable hooked up with BNC) to replace, in
the long run, the expensive thick inflexible tapped-transceiver version.
The nice thing about this approach is total compatibility with Ethernet both
electrically and logically, so you can extend your ethernet across the street
with Ungermann-Bass/Seicor/Fiberlan's fiber-optic (and expensive) Ethernet,
and run cheap cables and transceivers within buildings.  You get a big building,
and you'll need some repeaters, especially since you'll use more footage of
cheapernet, actually running by EACH node, rather than lots of expensive
multiconductor transceiver cable dropping from transceivers placed at the
site of the thick cable.  (Xerox' repeaters work fine on cheapernet, by my
actual experience).  With the advent of VLSI ethernet controllers, the main
cost remains in the transceiver.  When THAT finally goes VLSI, Ethernet will
*truly* be cheap.  But don't hold your breath yet...analog isn't trivial.
[ucbvax,decvax,ihnp4]!sun!sunny	(Sunny Kirsten of Sun Microsystems)