Transparent Asynchronous Transmitter/Receiver Interface 4-byte/5-byte An encoding scheme used for Fiber Distributed Data Interface (FDDI) LANs as well as for Asynchronous Transfer Mode (ATM). Supports speeds of up to 100 Mbps over multimode fiber. TAXI is the chipset that generates 4B/5B encoding on multimode fiber. See also 4B/5B local fiber.