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From: wsmith@umn-cs.CS.UMN.EDU (Warren Smith [Randy])
Newsgroups: comp.dcom.lans
Subject: Re: Ethernet over twisted pair: a summary of the "whys"
Message-ID: <17401@umn-cs.CS.UMN.EDU>
Date: 1 Dec 89 00:41:19 GMT
References: <4686@blake.acs.washington.edu> <249@cfa.HARVARD.EDU>
Reply-To: wsmith@umn-cs.cs.umn.edu (Warren Smith [Randy])
Organization: CSci Dept., University of Minnesota, Mpls.
Lines: 36

In article <249@cfa.HARVARD.EDU> sward@cfa.HARVARD.EDU (Steve Ward, CF) writes:
>There is a major reason we find twisted pair ethernet attractive at our
>site:  network bandwidth management and conservation in the face of
>growing numbers of remote file server/multiple client workstation
>groups.
[text deleted]
>.....  Enter twisted pair:  Aha!  Now each node, no matter its
>location, get connected to a central wiring hub.  At wiring hub clusters
>of machines, independent of physical location, can be placed on the same
>segment which can be bridge isolated.

At the risk of beating this subject to death, I would like to point out
that you can use the exact same configuration using thinnet.  Run one
thinnet to each device and connect them all to standard thinnet multiport
repeaters.  There are even some advantages to doing it this way:

 1) longer distance per run
 2) lower cost - the twisted pair equipment is alot more expensive
    when your devices have built in thinnet xcvrs (as most now do)
    You can but an 8 port thinnet multiport for <$2K and 4 port <$1.4K
 3) more noise immunity/less RF
 4) you can daisy chain off another device if a quickie install is needed

Of course, there are disadvantages to thinnet as well.  Two that are
relevant to the star topology are:

 1) thinnet multiports are rather stupid about disconnecting screwed up
    segments, which can result in a hung network.
 2) thinnet patch panels/closet hardware/wall plates/etc are harder to come
    by and more expensive than telco type stuff.

Randy
-- 
Randy Smith
wsmith@umn-cs.cs.umn.edu
...!rutgers!umn-cs!wsmith