On a Cut-Off Threshold Delay-Loss System with N Types of Traffic for Overload Protection

The cut-off threshold mechanism was traditionally used for overload protection in switching systems but is also valid for today´s packet communications. In such systems, traffic flows are served in a prioritized manner and priorities are assigned to each type of traffic flow by defining the threshold limits for accessing the group of servers. We present an analytical study of a cut-off threshold delay-loss system with N types of input traffic flows instead of restricting the investigation to two or three types of input traffic sources in previous studies. In this paper, we present the generalized formulae in terms of N for characterizing the performance measures, i.e., blocking and waiting probabilities. Specifying and incorporating any value of N, we can obtain the exact formulae for characterization of the system. Also, we discuss an example in which five types (N = 5) of traffic flows are offered to the system for which blocking and waiting probabilities are presented in graphs. These probabilities are calculated by means of the iterative successive over relaxation (SOR) method.