[ILUG] [OT] ethernet repeaters

Paul Jakma paul at clubi.ie
Fri Mar 8 12:38:47 GMT 2002


On Fri, 8 Mar 2002, Niall O Broin wrote:

> There's a limit there in the number of switches you can have - I think it's
> four, but I could be wrong. How long is really long ?

iirc, the old 5-4 rule: no more than 5 segments and 4 repeaters
between any 2 nodes on the ethernet.

also, iirc, with 10BaseT each segment is limited to 85M, well, 100M,
(eg if using crossover) as it presumes a hub's internal wiring
consumes the equivalent of 15M worth of cable in noise, etc.. (though
a switch probably does not have those issues and possibly could be
100M).

i presume 100BaseT is pretty similar.

> Yes, that's the definitive answer - up to 10km fairly handily, and longer
> possible. Cost of cable, installation, and magic boxes at each end of the
> cable will be a tad more than Wesley's ganged switches answer though.

or why not use 10Base5? 5 segments of 500M each with 4 repeaters =
2.5Km achievable.

should be a lot cheaper than fibre. (but hard to find perhaps.)

> Niall

regards,
-- 
Paul Jakma	paul at clubi.ie	paul at jakma.org	Key ID: 64A2FF6A
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