100BaseFX, also known as 100Base-FX, is a 100-Mbps baseband Fast Ethernet specification. 100BaseFX, a part of 100BaseX defined in the IEEE 802.3 standard, uses 4B/5B block encoding for Fast Ethernet over fiber-optic cabling. The fiber distance that the 100BaseFX can support is: 412m half duplex on Multi Mode fiber, 2km full duplex on Multi Mode fiber, and 15-20km full duplex on Single Mode fiber.
