Linksys AUTOSENSING WORKGROUP SWITCH EZXS55W - Manual (Page 9)

Straight-Through Twisted Pair Wiring
Crossed-Over Twisted Pair Wiring
11
EtherFast 10/100 Autosensing Switches
Types of Ethernet Cabling
Twisted-pair cabling comes in various grades, or categories. Category 5 is
required for Fast Ethernet, and is also the most reliable and most commonly
used type of cabling.
You can buy Category 5 UTP (Unshielded Twisted Pair) cabling in pre-
crimped lengths, or you can crimp your own. Crimping your own cabling can
result in faulty connections if the RJ-45 tips are not secured properly.
Precrimped Category 5 ethernet cabling is available at most computer retail
stores.
The most common type of Category 5 cabling used is UTP, or “unshielded
twisted pair.” STP, or “shielded twisted pair,” wiring is only necessary for
network environments exposed to excessive amounts of electromagnetic inter-
ference, or EMI. These environments include areas with high sources of elec-
trical power, air conditioning, generators, and radio signals. STP cabling is
also used for wiring outdoors.
In a straight-through cable, wires 1, 2, 3 and 6 at one end of the cable are
still wires 1, 2, 3, and 6 at the other end. In a crossover cable, the pairs are
reversed so that wire 1 becomes 3 at the other end of the cable, 2 becomes 6,
and so forth.
In building your Fast Ethernet network, it is highly recommended to use only
straight through cabling. Use crossed over cabling as a last resort when there
are no uplink ports available.
To determine which wire is wire 1, hold the RJ-45 connector with the spring
clip facing towards the ground and the copper connectors pointing away from
you, with the wires exposed upwards to your view. The first wire on the far
left is wire 1. You can also refer to the illustrations and charts of the internal
wiring on page 11.
10
Instant EtherFast ® Series