Path: utzoo!utgpu!jarvis.csri.toronto.edu!cs.utexas.edu!yale!umich!pmsmam!pmsmam.uucp!wwm
From: wwm@pmsmam.uucp (Bill Meahan)
Newsgroups: comp.dcom.lans
Subject: Re: Broadband backbone
Message-ID: <1990Feb26.205700.14936@pmsmam.uucp>
Date: 26 Feb 90 20:57:00 GMT
Sender: wwm@pmsmam.uucp (Bill Meahan)
Distribution: na
Organization: Ford Motor Co EFHD Ypsilanti Plant, Ypsilanti MI
Lines: 41

Sorry for positing this to the net but my reply by e-mail bounced.
Besides, others may be interested.

In article <6574@cps3xx.UUCP> you write:
>
>We are looking to connect a group of a dozen or so Netware based servers
>through an existing 75 ohm cable (about 270 Mhz Bandwith I think).  We
>already run several video channels through it.  The system runs almost
>everywhere on our campus.  To rewire would be really expensive.  An
>Arcnet or MAP style protocal might work really well in this situation
>(first impression.)  We have people with the experience to deal with
>RF-modems, but I don't know what kind of Network adaptors (for the 
>internal bridge in the server) or what style modems would work the best.
>What kind of bandwidth would this take up?
>
>Could someone that has done this before please share some of their
>experiences?
>
>Thanks
>Keith
>delong@frith.egr.msu.edu
>Delta College

At our site, we are running a broadband backbone with a combination of
CCTV, Allen-Braley VistaLAN/1, PC-Net and a TCP/IP 'ethernet on broadband'
channel using Chipcom modems.  The Chipcom set uses a pair of 12-MHz channels
(similar to the other nets) with a 'head-end' remodulator to create a psuedo
loop for the 'ethernet'.  AUI cables from the 14 workstations/minis on the
ethernet simply plug into the Chipcom units (which are available in 
1,2,4 or 8-port versions) as if plugging into a MAU.  Once group of
4 systems in the same room all plug into the same 8-port Chipcom and traffic
from one local unit to the next doesn't even go out onto the broadband!

So far, it;s been working for about 8 months without a hitch.

Good luck!
-- 
Bill Meahan			Starter Motor Engineering
				Ford Motor Electrical & Fuel Handling Div.
(313)484-9320			Ypsilanti Plant
uunet!sharkey!umich!pmsmam!wwm	128 Factory St.