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From: bruce@ccavax.camb.com
Newsgroups: comp.dcom.lans
Subject: <None>
Message-ID: <34972.273c6f33@ccavax.camb.com>
Date: 11 Nov 90 01:20:51 GMT
References: <1522@ariadne.csi.forth.GR>
Distribution: comp
Organization: Cambridge Computer Associates, Inc.
Lines: 20

In article <1522@ariadne.csi.forth.GR>, nicolas@csi.forth.gr (Nicolas Chrissakis) writes:
>                  ||||
>                  |||| <------- 4 wires (600 meters) under a road.
>                  ||||
>                  ||||
> I will like to connect the 2 Ethernet segments with these 4 wires.
> 
> Any suggestions?
> I do not want to put a baseband modem at 128 Kbits/sec to have a connection.

If the twisted pairs are suitable, a vanilla T1 ckt at 1.544mhz could go over
that. In Europe you folks use something near 2.048, but I don't know about
the cable driving. Here we get about 6000 feet between repeaters. We also
use T1C that is 2 x T1, but there are near end crosstalk problems where
your 2 pairs would get in trouble near each end (ear in mouth disease).

You then need a vanilla remote bridge or possibly router pair.

Since your distance is so short compared to 6000', that maybe you can find 
something less common to drive them nearer 10mhz. Good luck.