The effect of different packet size in a time-token protocol network that supports real-time applications

The Fibre Distributed Data Interface (FDDI) has become a standard for the new generation real-time systems. The correctness of such systems not only depends on the result of the computation and the error-free delivery of the message, it also depends on the time the result is generated and delivered. Messages missing their deadlines are usually of little use to the system. A miss in deadline may result from a degrade in performance to a disaster. The time-token protocol in the FDDl network allocates portions of network bandwidth to the stations (nodes) in the network for transmission. However, there are no standard rules on how to divide the bandwidth among the stations. This paper studies the "normalized proportional allocation scheme" proposed by Wei Zhao and looks into the effect of different packet size towards network utilization and in meeting real-time requirements.