Sun Microsystems Netra T4 AC100 Service And System Reference Manual page 277

100BASE-T Also known as Fast Ethernet, an Ethernet technology that supports a data
transfer rate of 100 megabits per second over special grades of twisted-pair
wiring. 100BASE-T uses the same protocol as 10BASE-T. There are three
subsets of the 100BASE-T technology: 100BASE-TX defines digital transmission
over two pairs of shielded twisted-pair wire. 100BASE-T4 defines digital
transmission over four pairs of unshielded twisted-pair wire. 100BASE-TX
defines digital transmission over fiber-optic cable.
Glossary 5