Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!mailrus!ames!sgi!ian@lassen.wpd.sgi.com
From: ian@lassen.wpd.sgi.com (Ian Clements)
Newsgroups: comp.protocols.tcp-ip
Subject: Re: Thick or Thin
Summary: cost, cheaper?
Message-ID: <42457@sgi.sgi.com>
Date: 3 Oct 89 16:23:02 GMT
References: <8910022022.AA09420@aqua.whoi.edu>
Sender: ian@lassen.wpd.sgi.com
Organization: Silicon Graphics, Inc., Mountain View, CA
Lines: 35

In article <8910022022.AA09420@aqua.whoi.edu>, mep@AQUA.WHOI.EDU (Michael E. Pare) writes:
> 
> ...This can be the least costly to install if the twisted pairs
> (just one using 3COM's system, or two for Synoptics or eventually the 
> 10BASET standard) are already available.  

 I disagree.  Remember that you need one transceiver for each workstation
regardless of whether or not you use thick, thin or twisted pair (assuming that
no workstation already has a thinnet xcvr installed).  I'm calling the xcvr
costs a wash even though there is a $50 difference between thin and twisted
pair (thin being least expensive and twisted pair most expensive).  So we can 
assume that all that is being compared is transmission medium and associated 
equipment, correct?  
 
 Following that assumption, the cost to acquire backbone cable for thick
or thin costs $1.25/ft and $.29/ft respectivly.  Twisted pair cable costs 
$.05/ft.  The twisted pair cable it self is much cheaper however, to make 
the whole thing work you need this box (commonly refered to as an Active 
star repeater) that can cost somewhere around 8k for more than 10 connections.

 Admittedly, once the twisted pair system is up and running, maintenance,
additions and other changes are far easier to deal with.  One can almost 
always install more twisted pair cable than either thick or thin backbone
and drop cables for the same costs.  Here at SGI for example, every office and
cube gets a 4 port data block.  From that block you can have Ethernet, 
PhoneNET (AppleTalk) and serial connections.

 Then of course there is the issue of the 10BASET spec which is to be 
released soon.  What does that mean to those of us with large twisted pair
installations?


	Cheers,

	Ian