FICON (for Fiber Connectivity) is a high-speed input/output (I/O) interface for mainframe computer connections to storage devices. As part of IBM's S/390 server, FICON channels increase I/O capacity through the combination of a new architecture and faster physical link rates to make them up to eight times as efficient as ESCON (Enterprise System Connection), IBM's previous fiber optic channel standard.
FICON channel features include:
- A mapping layer based on the ANSI standard Fibre Channel-Physical and Signaling Interface (FC-PH), which specifies the signal, cabling, and transmission speeds
- 100 Mbps bi-directional link rates at distances of up to twenty kilometers, compared to the 3Mbps rate of ESCON channels at distances of up to three kilometers.
- More flexibility in terms of network layout, because of the greater distances
- Compatibility with any installed channel types on any S/390 G5 server
- Bridge feature, which enables support of existing ESCON control units
- Requires only one channel address
- Support for full-duplex data transfers, which enables simultaneous reading and writing of data over a single link
- Multiplexing, which enables small data transfers to be transmitted with larger ones, rather than having to wait until the larger transaction is finished