Path: utzoo!attcan!uunet!husc6!rutgers!mailrus!cornell!batcomputer!lynch
From: lynch@batcomputer.tn.cornell.edu (Tim Lynch)
Newsgroups: comp.protocols.appletalk
Subject: Re: lengthening Atalk network
Summary: be careful in how you string it all together...
Message-ID: <7231@batcomputer.tn.cornell.edu>
Date: 21 Jan 89 15:01:04 GMT
References: <Added.AXox94y00Ui34RaU8M@andrew.cmu.edu> <303@lloyd.camex.uucp>
Organization: Theory Center, Cornell U., Ithaca NY
Lines: 61

>
> I have never used Faralon's star controller, but I am pretty sure that
> each `arm' of the star can have many Macintoshs AppleTalked onto it.
> Just do the regular daisy-chain routine.  You are not forced to use a
> pure star wiring scheme, it can be a hybrid design.
> 

True, but be careful.  Stick with the guidelines as presented in the
Farallon literature.  Each arm of the Star Controller is seen as an
appletalk net, though you will no doubt run into problems with
congestion long before you come up against the physical limit on
number of machines.  We have.

The wiring must not be pure star, but, again, read Farallon's doc's.
For example, one run of our star controller, located at one end of
the building, goes to our administrative wing at the other end.  There
the twisted pair daisy-chains to about 8 Mac's and printers _and_
continues up a floor to several more Macs.  In addition to this leg,
we've got another leg running into an adjacent room with two mac's.
Note that from one of the Mac's in the admin wing, we simply daisy
chain via the PhoneNet blocks to some other macs. We've done this
at several locations throughout the net and haven't had any problems
with it.  Well, let me rephrase that, we can't attribute any problems
we've had to this configuration.  My little diagram shows just one
of the twelve legs of the star controller:

                             (short run to room adjacent to Star C)
Star Controller ] ----------------------------------------------- 
                   |                                     |      |
                   |                                    Mac    Mac
                   |
                   |---- LW 
                   |
                   |---- Mac
(admin wing)       |  
                   |   ( not all machines shown)
                   |
                   |---- Mac ---- Mac ---- LW
                   |
                   | 
                   |
                   |
                   |      (second floor)
                   ------------------------
                          |               |
                          |               |
                         Mac             Mac


We've got a good size net (~40 Macs, half dozen laserwriters, half
dozen PC's, a star controller, bridges, and a Kinetic box) running
Appleshare.  We've run everything over twisted pair originally strung
thoughtout the department buildings to support async terminals tied
to the departmental machine.  In tracing any one pair of wires from the
Star Controller to a Mac "flock" or "gaggle", say the Admin wing, you
would find that the wires originally went through "punch down" blocks.
These are the quick-connect things the phone company used in the old
Centrex systems.  I say all this because if you intend to make use of
pre-existing wiring -- DON'T GO THROUGH PUNCH DOWN BLOCKS !!!  We've
had to go through our entire net, pulling wires free of the punch-down
blocks and soldering them directly.  Really cleaned things up though.