Fast Ethernet
In computer networking, Fast Ethernet is a collective term for a number of Ethernet standards that carry traffic at the nominal rate of 100 Mbit/s (the original Ethernet speed was 10 Mbit/s). Of the Fast Ethernet standards, 100BASE-TX is by far the most common.
Fast Ethernet was introduced in 1995 as the IEEE 802.3u standard and remained the fastest version of Ethernet for three years before it was superseded by the Gigabit Ethernet.
General design
Fast Ethernet is an extension of the 10-megabit Ethernet standard. It runs on UTP data or optical fiber cable in a star wired bus topology, similar to 10BASE-T where all cables are attached to a hub. Fast Ethernet provides compatibility with existing 10BASE-T systems, enabling plug-and-play upgrades from 10BASE-T. Fast Ethernet is sometimes referred to as 100BASE-X, where "X" is a placeholder for the FX and TX variants. The standard specifies the use of CSMA/CD for media access control, although in practice all modern networks use Ethernet switches and operate in full-duplex mode.
