This paper gives an overview of research on real-time communication over systems area networks (SANs). Our project is focused on developing real-time services for switched Ethernet networks, keeping the Ethernet and TCP/IP Internet communication standards [1]. Switched Ethernet is extended to allow for periodic real-time traffic using earliest deadline first (EDF) scheduling [1] [2]. We have shown the advantage of supporting special communication patterns apparent in industrial and embedded systems [3]. We have made some implementation that will demonstrate the support of both guaranteed real-time communication and efficient services for parallel and distributed computer systems by an Ethernet switch with added software.