100BASE-TX

100BASE-TX is the predominant form of Fast Ethernet, providing 100 Mbit/s Ethernet.

100BASE-TX runs over two pairs of wires in category 5 cable. Like 10BASE-T, the proper pairs are the orange and green pairs (canonical second and third pairs) in the TIA-568B wiring standard.

In TIA-568B, wires are in the order 1, 2, 3, 6, 5, 4, 7, 8 on the modular jack on each end. The colour-order would be orange/white, orange, green/white, blue, blue/white, green, brown/white, brown:

RJ-45 Wiring (EIA/TIA-568B)

Pin	Pair	Wire	Color
1	2	1	white/orange
2	2	2	orange/white
3	3	1	white/green
4	1	2	blue/white
5	1	1	white/blue
6	3	2	green/white
7	4	1	white/brown
8	4	2	brown/white

Each segment can have a maximum distance of 100 metres. Capable of 100 Mbit/s throughput (200 Mbit/s in full-duplex configurations). See IEEE 802.3 for more details.

The configuration of 100BASE-TX networks is very similar to 10BASE-T. When used to build a local area network, the devices on the network (computers, printers etc.) are typically connected to a hub or switch, creating a star network. Alternatively it is possible to connect two devices directly using a cross-over cable.

See also

• 100BASE-FX
• RJ-45
• 25-pair color code
• MLT-3 Encoding

References