X-Mailer: ELM [version 2.3 PL11]
Newsgroups: bit.listserv.novell
Date:         Mon, 27 Jul 1992 18:58:08 CDT
Reply-To:     Novell LAN Interest Group <NOVELL@SUVM.BITNET>
From:         rfranken@CS.UMR.EDU
Subject:      Re: ? on Token Ring Distance Work-around
X-To:         NOVELL@suvm.acs.syr.EDU
              "DUNES%SJSUVM1.BITNET@SUVM.SYR.EDU" at Jul 27, 92 7:03 am

>
> Help!  Our campus support staff gives us a different story every time
> we ask for recommendations.  We have already ordered pieces for our LAN
> and have  5 nodes that are > 320 feet away.  These people will be phased
> into the LAN in December.  We are using Type 3 twisted pair wire.  Can
> someone suggest a way to connect all these people ( 4 of whom are in
> one office)?
>
> We were originally told that we could put a MAU near the 4 people, and
> use IBM coax or fiber to connect that MAU to our current MAU.  Now we
> are being told to get a separate fileserver for these 4 folks, and
> spend $9,000 to connect them to a router to allow them to use our LAN.
>
> Is there a more cost effective way to incorporate the 4 people onto our
> LAN?  (The other 1 person is within 320 feet of these 4).
>
> Please respond directly to me and I will summarize.
>
> P.S. we are using Novell 3.11, 486-50 fileserver, 4/16 switchable TR cards
> over unshielded twisted pair wiring.  (We could use shielded twisted pair
> for our 5 more remote users since their stations all require new wiring
> to be installed).
>
> Thanks for any assistance.
>
> Mike Dunefsky                Internet:  DUNES@SJSUVM1.SJSU.CSN.EDU
> Systems Analyst              Bitnet:    DUNES@SJSUVM1.BITNET
> San Jose State University
>
I don't remember off the top of my head what all the TR distance limitations
are (and I'm not at work so I can't look them up), but if Shielded Twisted
Pair will work, then thats one solution; otherwise, it looks like Coax or
Fiber (IMHO, Coax is not the way to go, unless you already have Coax run
to the location, it which case it would be cheaper than pulling new
fiber).

The following would apply to STP, Coax, or Fiber:

Since most of the cost of cabeling is (usually) the labor cost of getting
it put in, you could just get one cable per person.  This is probably the
way to go for STP; however, for fiber, you would then need four pairs of
Fiber to Copper converters.

A MAU for these people is another possibility - you would then need two
connections between the two sites (one for ring-in, another for
ring-out).  (Of course, you caould run the ring in a "C" by not bringing
back the Ring-Out, but I don't reccommend that).

A third possibility is to extend a single lobe port out to these people.  Two
ways here - one is to buy a "ring quadrupler" which is a device designer for
this purpose - it has one port that connects to a MAU port, (and provides
the 5V phantom voltage as necessary), and has four user ports on it.  This
would then require one connection (STP (if the distance is OK) or fiber)
back to the main site.  A second way (if you are going fiber) is to connect
a lobe port on a MAU at the main site to a lobe port on a MAU at the remote
site.  This won't work on STP because neither site would provide the five
volts to open the relay at the other site, but many fiber converters can
be configured to provide the five volts.

My reccommendation -- (IMHO) if the distance is OK for STP runs (I don't
think 320 ft is close enough, but it may be) then run 4 STP cables (or
more, if you anticipate future users....).  If STP is too long, then I
would use Fiber.  The best way is a ring-in ring-out connection (which
would require two fiber pairs and two pairs of fiber<->copper converters).
Remeber, the labor of pulling fiber is the same for 2 fibers or four ... If
money is very important, then use a lobe-lobe type connection over one
fiber pair (then you only need 1 pair of fiber<->copper converters).

One last thought ... if 320 ft it too long for STP according to the Token-Ring
spec, it may work anyway; and the temptation may be to use it.  I currently
administer (along with other people) two out-of-spec rings.  They work fine
normally, but when they go down, they are much harder to troubleshoot.  I
reccommend staying within spec.

          - Brett   (rfranken@cs.umr.edu ... not speaking for umr!)
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