Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!rutgers!aramis.rutgers.edu!geneva.rutgers.edu!hedrick From: hedrick@geneva.rutgers.edu (Charles Hedrick) Newsgroups: comp.dcom.lans Subject: Re: Ethernet max length problems Keywords: repeaters? ethernet too long Message-ID:Date: 25 Sep 89 17:28:19 GMT References: <634@elan.elan.com> Organization: Rutgers Univ., New Brunswick, N.J. Lines: 25 To: jlo@elan.com The answers people have been giving you are right as far as they go, but have not mentioned something. Most typically large thin-net installations are done in relatively small pieces, using a thin-net multiport repeater to connect them. The problem with thin-net is that you daisy-chain it, so that if somebody disconnects one machine it affects every other machine down the line. It's rather hard to maintain a network that has 100 machines daisy-chained. So the idea is that you daisy-chain small groups of machines that are fairly close together, and then use a multiport repeater to connect the groups. A multiport takes something like 8 segments of thinnet and one of thicknet. If your systems are fairly close together, you may be able to use just a single multiport repeater. If you have a larger installation, you install a thicknet as a "backbone", and then have several multiport repeaters connected by the thicknet backbone. I'm sure you can get a conventional repeater (i.e. a thing that connects two segments) for thin-net, but normally what you find for thin-net are multiport repeaters. Just about all the standard Ethernet vendors make them: We tend to use Cabletron, but DEC certainly makes them (DEMPR), and I'm sure 3Com and all the other Ethernet vendors do as well. At some point you'll want to use a bridge or router rather than just a repeater. Do that when you have enough traffic that you don't really want all the machines on the same network.