Simulated Perfromance of a Ring-Switched Data Network

The digital data-transmission network studied takes the form of interconnected loops or rings of users. The present report describes a simulation study of a single ring of users undertaken for the dual purpose of observing and evaluating such quantities as message delay, buffer occupancy, and busy-idle periods, and of comparing previous analytical work concerning message delay with values obtained from simulation. The study focused on homogeneous users although other user populations are discussed. Other aspects examined, though not in as great detail, are effects of quantization of message segments, line utilization, and system capture by competing communities of users. Principal conclusions reached can be stated as follows. 1) Under quite reasonable conditions, user-induced message delay is small for moderate line loads. 2) Simulated delays and theoretical estimates of message delays are in good agreement over a wide range of line loads.