Path: utzoo!attcan!uunet!cme-durer!wallace
From: wallace@cme-durer.ARPA (Evan Wallace)
Newsgroups: comp.dcom.lans
Subject: Re: Do you know about TCL?
Summary: multiport xceivers daisy chain limits
Message-ID: <735@morticia.cme-durer.ARPA>
Date: 18 Nov 88 14:50:18 GMT
References: <853@amethyst.ma.arizona.edu>
Organization: National Bureau of Standards, Gaithersburg, MD
Lines: 35

In article <853@amethyst.ma.arizona.edu>, chris@spock (Chris Ott) writes:
> ... You can take
> an output from the first multiport box and plug it into the input of the
> second, effectively giving you seven more connections without another
> tap on the coax. As far as I know, this goes to infinity.
> 

Remember however that the total length of a drop (AUI) cable cannot
exceed 50 meters.  That means from any machine to the trunk cable.
Check with TCL on a limit on the number of boxes that can be daisy
chained, I have heard conflicting reports on this.

I agree with the general tone of the quoted message.  Our TCL multiport
tranceivers have proved reliable and flexible during the four years
we have used them.  

Advantages of the multiport concept have been:

		ease of isolation for debugging purposes
		ease of installation (fewer taps)
		increase in effective cable length (none wasted adding multiple 
			taps for a single room)
		ease of reconfiguration (move box from net to net easily)
		improved overall reliability (taps have been the least reliable
			part of are E'net installations)

Disadvantages:
		?


Evan K. Wallace at the 
National Institute of Standards and Technology (formerly the NBS)

wallace@cme.nbs.gov
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