Twisted-pair cabling, also known as
10BaseT, is ideal for small, medium, or large networks that need
flexibility and the capacity to expand as the number of network
users grows. I highly recommend using 10BaseT cabling for
its amazing flexibility and reliability.
In a twisted-pair network, each PC has a
twisted-pair cable that runs to a centralized hub. Twisted-pair
is generally more reliable than thin coax networks because the
hub is capable of correcting data errors and improving the
network's overall transmission speed and reliability. Also known
as uplinking, hubs can be chained
together for even greater expansion.
There are different grades, or categories,
of twisted-pair cabling. Category 5 is the most reliable and
widely compatible. It runs easily with 10Mbps or networks, and
is required for Fast Ethernet. You can buy Category 5 cabling
that is pre-made, or you can cut & crimp your own.
Category 5 cables can be purchased or
crimped as either straight-through or crossed. A Category 5
cable has 8 thin, color-coded wires inside that run from one end
of the cable to the other. Only wires 1, 2, 3, and 6 are used by
Ethernet networks for communication. Although only four wires
are used, if the cable has 8 wires, all the wires have to be
connected in both jacks.
cables are used for
connecting computers to a hub. Crossed
cables are used for connecting a hub to another hub,
there is an exception: some hubs have a built-in uplink port
that is crossed internally, which allows you to uplink hubs
together with a straight cable instead.
In a straight-through
cable, also known as a patch cable,
wires 1, 2, 3, and 6 at one end of the cable are also wires 1,
2, 3, and 6 at the other end. In a crossed cable, the order of
the wires change from one end to the other: wire 1 becomes 3,
and 2 becomes 6.
To figure out which wire is wire number 1,
hold the cable so that the end of the plastic RJ-45 tip, (the
part that goes into a wall jack first), is facing away from you.
Flip the clip so that the copper side faces up, (the springy
clip will now be parallel to the floor). When looking down on
the coppers, wire 1 will be on the far left.