Future satellites should be able to support not only circuit switched data communication, such as voice and video traffic, but also bursty traffic based on connectionless data communication generated in (High Speed) LAN. Further they should support the low power stations, such as VSAT-Stations or mobile users. The satellite could be used as a network nodc in Store-and-Forward networks or as a switchboard in a telephone network to reduce round trip dclay in satcllite links. These requirements lead to the dcsign of future on-boardprocessing satellites. While current satellites are designcd for circuit switched data communications, future satellites will be based on hybrid circuit/packet switches or advanced fast packet switches. These will be combined with suitable network management and congestion control techniques to ensure proper availability and dclay characteristics for delay sensitive tnftic.