Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!ames!hc!pprg.unm.edu!unmvax!charon!ariel.unm.edu!dd
From: dd@ariel.unm.edu
Newsgroups: comp.dcom.lans
Subject: Request For Opinions:  Optical Fiber Physical Topologies
Message-ID: <4824@charon.unm.edu>
Date: 12 Apr 89 14:33:48 GMT
Sender: root@charon.unm.edu
Reply-To: dd@ariel.unm.edu
Organization: University of New Mexico, Albuquerque, NM
Lines: 37



At UNM, our network is organized as a backbone network (broadband, with
each active 6 MHz channel functioning as a 5 Mbps CSMA/CD "Ethernet
like" data channel), serving as in inter-building transport for
Ethernets.  The Ethernets are "glued" to a particular broadband channel
in a MAC filtered fashion - no flames please, TCP/IP isn't everywhere
it should be yet, and we have a very cooperative user community.

As we move into distributed image processing (expected to occur in the
next 2~3 years), I need a better backbone.  Also, the cost of extending
our private CATV system is now (finally!) higher than the cost of
extending an optical fiber backbone.  And there are other advantages
(which you all know more about than I do, in all likelyhood).  So fiber
it is.  And of course, the "right" way to go is to install an FDDI
compatible wiring plant, and drive it with FDDI-non-compliant
electronics, temporarily.

FDDI is logically a token ring system, but the wiring plant may
optionally be "star-shaped", i.e., go out to a building, and come back
to a "wiring center", and go out to the next building, and come back
in,... and so forth, ad nauseum.

My question, addressed to anyone who has a solid argument, but
particularily to folks who might have installed an FDDI compatible
wiring plant is:  What is the best way to go?  Should I build a ring,
or a star-shaped ring, or a ring of rings, or a ring of stars, or
what?  I realize that the ultimate decision will depend on the
particulars of our campus, but if anyone can think of factors that I
ought to consider, please let me know.

Thank you all for your help!

Don Doerner				dd@ariel.unm.edu
University of New Mexico CIRT
2701 Campus Blvd, NE
Albuquerque, NM, 87131			(505) 277-8036