Path: utzoo!attcan!uunet!husc6!bloom-beacon!apple!claris!clay
From: clay@claris.UUCP (Clay A. Maeckel)
Newsgroups: comp.dcom.lans
Subject: Re: Running a LAN off the existing RJ-45 phone lines
Keywords: Ethernet twisted pair 3Com
Message-ID: <5906@claris.UUCP>
Date: 10 Oct 88 14:24:55 GMT
References: <1238@umbc3.UMD.EDU> <25288@bu-cs.BU.EDU>
Reply-To: clay@claris.UUCP (Clay A. Maeckel)
Organization: Claris Corporation, Mountain View CA
Lines: 34

In article <25288@bu-cs.BU.EDU> kwe@buit13.bu.edu (Kent England) writes:
>In article <1238@umbc3.UMD.EDU> dipto@umbc3.umd.edu (Dipto Chakravarty) writes:
>>I need some wisdom and/or recommendation on selecting a LAN that will 
>>be able to use the existing 4-conductor phone lines in the office as 
>>unshielded twisted pairs.
>
>	Finally, there is Ethernet 10BaseT.  It isn't a standard yet,
>but it will be and it will work.  It is very uncertain how well it
>will work over all installations, but if you tailor your twisted pair
>to minimize crosstalk, etc you will find that unshielded twisted pair
>Ethernet will do the job very well.  The nice thing about Ethernet is
>that TCP/IP has been running on Ethernet for years and your protocol
>problems are nonexistent.
>

At Claris we have been running quite nicely with 3Com's PairTamers. Just
put this small box on each end of a single twisted-pair and you can run
RG-58 coax out both boxes. We have run DECNet, TCP/IP, XNS, and AppleTalk
across these guys. The ethernet part of our network is shaped somewhat
like a star with 3Com's MultiConnect Repeater at the center, going to
twisted pair, coming out with coax 150 to 300 feet away from the repeater,
and chaining 1 to 4 Macs.  We are also using 3Com Ethernet boards in our
Macs.  There was a problem of mixing Sun's and Mac's at the end of run,
but putting the two Sun's at the end of their own run solved those problems.

We don't have many PC's and none with Ethernet cards but the network should
work just as well with those machines.  BTW: what is Ethernet 10BaseT, is
that the 2 twisted-pair (somewhat) standard?


-- 
 Clay Maeckel         *   UUCP: {ames,apple,portal,sun,voder}!claris!clay
 (I know nothing!)    *   Arpanet: claris!clay@ames.arc.nasa.gov
 Claris Corporation   *   AppleLink: Maeckel1   *   CompuServe: 73057,255