Path: utzoo!attcan!lsuc!ncrcan!brian
From: brian@ncrcan.Toronto.NCR.COM (Brian Onn)
Newsgroups: comp.dcom.lans
Subject: Re: ANC connectors
Keywords: testing and alternatives
Message-ID: <920@ncrcan.Toronto.NCR.COM>
Date: 23 Sep 88 05:52:09 GMT
References: <157@ernie.NECAM.COM> <22961@amdcad.AMD.COM>
Reply-To: brian@ncrcan.Toronto.NCR.COM (The Super User)
Organization: NCR Canada Ltd., Mississauga, Ontario
Lines: 26

In article <22961@amdcad.AMD.COM> rpw3@amdcad.UUCP (Rob Warnock) writes:
>In article <157@ernie.NECAM.COM> animal@ernie.NECAM.COM (Alan R. Silverman)
>writes:
>+---------------
>| Connecting two transceivers to a short length of cable can be expensive
>| and a pain in the butt.  A minimum length backbone cable is required.
>| I don't know the length, but its around a hundred or so feet.
>+---------------
>
>This is *NOT* true! There is no minumum length requirement at all! Even the
>2.5 meter transceiver spacing rule is needed only on long cables with dozens
>of transceivers. You can safely put 2-10 (or so) transceivers on as small
>a piece of cable as will fit (say, 6 inches per transceiver). It's done all
>the time.  (Just remember, though, you still need terminators at both ends.)

I'm not disputing the idea of putting transceivers every 6 inches or so,
but what kind of havoc does this wreak on the ethernet?  I thought the 
2.5 meter separation rule was there to prevent/minimize reflections on the
medium?  

Whether or not you get reflections (at some transceiver separation) would
depend (not entirely) upon the wavelength of the signal on the medium,
right?.  So what is the wavelength of a manchester encoded signal at
ethernet speeds?  

Brian.