Variability of queue length and waiting times in a system with general service times

An essential issue in telecommunication network design and performance analysis involves determining how variability in arrivals and service affects system congestion. In particular, focus is placed on queue length, which corresponds to the number of waiting packets, and on delay, which is the main factor influencing flow performance. To ensure a given level quality of service, it is important to know these values before transmission or processing. The article demonstrates the impact of observation time on the estimated mean number of packets in the system, as well as on the mean packet waiting time in the queue, for a queueing system with a general service time. The results obtained for two different service time distributions, with constant and variable coefficients of variation, were compared with each other and with theoretical values.