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Path: utzoo!utgpu!water!watmath!clyde!rutgers!sunybcs!kitty!larry
From: larry@kitty.UUCP
Newsgroups: comp.dcom.modems
Subject: Re: Twisted Pair Ethernet
Message-ID: <2250@kitty.UUCP>
Date: Fri, 20-Nov-87 20:35:18 EST
Article-I.D.: kitty.2250
Posted: Fri Nov 20 20:35:18 1987
Date-Received: Sun, 22-Nov-87 12:55:58 EST
References: <2247@kitty.UUCP> <[STL-HOST1.ARPA]Fri,.20.Nov.87.07:29:01.CST.SNELSON>
Organization: Recognition Research Corp., Clarence, NY
Lines: 21
Summary: Shielding T1 circuits...

In article <[STL-HOST1.ARPA]Fri,.20.Nov.87.07:29:01.CST.SNELSON>, SNELSON@STL-HOST1.ARPA writes:
> LETS NOT MIX UP BITS AND HERTZ. ON IN HOUSE T-1 WE MAKE SURE THAT
> THE SEND AND RECEIVE ARE IN SEPARATE CABLE BUNDLES. THEY DON'T
> CROSS TALK TO EACH OTHER THAT WAY.

	There is special outside telephone cable available for T1 use
which divides cable pairs into two major bundles, using a Z-shaped
shield which makes contact with the outer alpeth shield.  Such an
arrangement allows separation of transmit and receive directions.
	However, much of the existing T1 carrier goes through conventional
telephone cables comprising only one overall alpeth shield.  Some attempt
is made to keep transmit and receive pairs in different 25-pair binder
groups, though.
	Crosstalk is not that much of a problem with T1 systems as long as:
(1) the outside cable is in decent shape and moisture-free; and (2) the
outside regenerators are installed at recommended locations.

<>  Larry Lippman @ Recognition Research Corp., Clarence, New York
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