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FWD: RE: Network cabling

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>From System ....: UUCP
>From Conference : EMail
MessageID ......: <1108.716T2850T13544805tom@carrott.org>
Originally from : Tom Parker <tom@carrott.org>
Originally to ..: deiban-firewall@lists.debian.org <deiban-firewall@lists.debian.org>
Subject ........: RE: Network cabling

Antropov Anton <dicobraz@mail.ru> wrote:

>Well, as you know UTP has radius of approx. 100 meters.

There is a wiring length, which depends either on the attenuation of the
wiring, or the maximum segment size.

The maximum segment size refers to the maximum size of a collision domain.
Basically if a node at one extreme of the collision domain sends the smallest
possible packet, and a node at the other extreme sends the a packet just
before the first packet arrives, then the second packet must reach the first
node before it finishes sending it's packet. If this doesn't happend then CDMA
doesn't work.

The attenuation length can be overcome with dumb repeaters. The maximum
segments size only with a more intellegent device. Exactly what, I'm not sure,
but I think most switches will do. A hub won't.

Optical fibre is preferable between buildings as it eliminates the possibility
of an electrical problem in one building destroying stuff in another via the
network. Think lightening. I don't know how important this is in practice.

Tom Parker - tom@carrott.org
           - http://www.carrott.org

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