Performance Studies of Multiple-Packet Multistage Cube Networks and Comparison to Circuit Switching

This paper extends the modeling and analysis of packet switched multistage cube intercoimection networks to include the use of multiple-packet message formats. A multiplepacket message format is needed within an interconnection network when the message to be transmitted exceeds the network's packet size. The packet offset time is introduced and used to gauge the transmission rate differential between the network interchange boxes and the system PEs. Based on assumed network and system operating characteristics, optimum network performance offset values are given. A methodology for evaluating the relative performance of circuit and packet switching transmission modes is developed. For an assumed set of network and system parameters, results indicate that, in contrast to inter-computer networks, the performance of packet switching networks is better than that of circuit switching networks for long message lengths.