What is 100Base-TX?

Computer EngineeringComputer NetworkMCA

100BASE-TX is the technical name of Fast Ethernet over twisted pair cables. It is a predominant form of Fast Ethernet carrying data traffic at 100 Mbps (Mega bits per second) in local area networks (LAN). It was launched as the IEEE 802.3u standard in 1995. Here, 100 is the maximum throughput, i.e. 100 Mbps, BASE denoted use of baseband transmission, and TX denotes use of twisted pair cables in Fast Ethernet.


  • This has either two pairs of unshielded twisted pairs (UTP) category 5 wires or two shielded twisted pairs (STP) type 1 wires.

  • One of these pairs transmits frames from hub to the device and the other pair transmits from device to hub, thus providing full-duplex communication.

  • Each network segment can have maximum length of 100m (328ft).

  • It has a data rate of 125 Mbps.

    The maximum fundamental frequency obtained is 31.25 MHz.

  • It uses MLT-3 encoding and decoding scheme along with 4B/5B block coding. 4B/5B block coding imparts spectrum shaping and DC equalization.

  • A cable connects only two nodes. Resulting in point-to-point connection topology. For connecting more than two nodes, a coupling element in used.

Updated on 05-Aug-2019 11:39:06