Path: utzoo!utgpu!jarvis.csri.toronto.edu!cs.utexas.edu!wuarchive!brutus.cs.uiuc.edu!zaphod.mps.ohio-state.edu!sunybcs!nsscb!njc
From: njc@nsscb.UUCP (Neil Cherry)
Newsgroups: comp.dcom.lans
Subject: Re: 10BaseT questions
Message-ID: <1252@nsscb.UUCP>
Date: 21 Feb 90 17:59:56 GMT
References: <6049@orca.wv.tek.com> <1393@disk.UUCP> <27060@cup.portal.com> <9317@portia.Stanford.EDU>
Reply-To: njc@nsscb.UUCP (Neil Cherry (STARGRP))
Organization: AT&T NSSC  S. Plainfield, NJ
Lines: 16

In article <9317@portia.Stanford.EDU> morgan@jessica.Stanford.EDU (RL "Bob" Morgan) writes:
>
>> Looking AT the connector end with the little tabby' thing pointed
>> down, the first pair is pin 1 and 2, the second pair is pin 3 and 6.
>Can anyone explain why the designers chose such a non-intuitive set of
>pins?  Naively one might think that the use of the standard pairs (eg,
>1 and 8 for one pair, 2 and 7 for another) would make more sense.
> - RL "Bob" Morgan

Actually it is a very intuitive design! Consider this plug a RJ-11 into a
RJ-45 jack. notice that the 2 center pins 4 and 5 ARE center (used for house
phones) then 3 and 6 are the 2nd house wires when the jacks were redesigned
for business  they added 2 outter wires to get our present setup. The amazing
part is that the twisted pair was originally use for 3kz bandwidth voice and
now it runs 10MHZ data.
NJC