How cat 5 cable work

• Ethernet Cat 5 cables have eight wires (four pairs).
• But under 10BaseT and 100BaseT standards (10 Mbps and 100 Mbps, respectively) only four (two pairs) of these wires are actually used.
• One pair is used for transmitting data and the other pair is used for receiving data.

• Cat5 cables can be work on either "straight-through" or "crossover."

Straight-through

• In a "straight-through" set-up for both plugs and sockets, pins 1 and 2 are used to transmit signals and pins 3 and 6 are for receiving signals.
• This wiring set-up is used for connecting computers to other network devices such as hubs or switches.

Crossover

• In a "crossover" set-up the assignations are reversed so that the transmitting plug pins connect to the receiving socket pins.
• This is used for connecting computers directly with one another.
• Cat 5 cable sockets can also be set up for internal crossover to receive "straight-through" cables.