100BaseX Ethernet Standard
The 100BaseX (Fast Ethernet) standard is an extension of the existing Ethernet standard. It runs on UTP Category 5 data grade cable and uses CSMA/CD in a star wired bus topology, similar to 10BaseT where all cables are attached to a hub.
100BaseX incorporates three media specifications:
- 100BaseTX (2-pair Category 5 UTP or STP)
- 100BaseT4 (4-pair Category 3, 4 or 5 UTP)
- 100BaseFX (2-strand fibre optic cable)
The TX indicates that the two of the four pairs in the cable are used, whereas T4 means that all four are being used and the FX means that the cable is two strand fibre-optic.