Fiber Distributed Data Interface is a media access (transmission) control-level protocol with token-ring architecture, a communication bandwidth of 100 Mbps and supported on a fiber network medium. To provide required ArcInfo communications, the workstation network communications software must include TCP/IP and NFS communication protocols, which the UNIX operating system provides. Packaging of TCP/IP communications for FDDI transmission is supported by a network interface card at the sending and receiving station, and this packaging is transparent to ArcInfo applications and data.