Path: utzoo!attcan!uunet!cs.utexas.edu!tut.cis.ohio-state.edu!ucbvax!D1.DARTMOUTH.EDU!c11234
From: c11234@D1.DARTMOUTH.EDU (Stan Dunten)
Newsgroups: comp.protocols.appletalk
Subject: Passive Stars
Message-ID: <8904111700.AA15637@dartvax.dartmouth.edu>
Date: 11 Apr 89 19:58:00 GMT
Sender: daemon@ucbvax.BERKELEY.EDU
Organization: The Internet
Lines: 12

We have about 4000 LocalTalk ports connected in about 400 passive stars and
found the following to work:

1. We limit the length of each leg of the star to about 100'.
2. We limit the total wire in a star to about 1000'.
3. Then we put a 20-30 ohm terminating resistor at the center of the star,
   none at the points.

Why does this work? My guess is that the wire lengths are so much shorter
than a LocalTalk bit on the wire that it acts more like a capacitor than a
transmission line. The resistor reduces the time constant to less than a
bit time.