Modeling of call server occupancy: A case study

The article presents problems of modeling and designing the necessary and adequate capacity of the call server input connections for serving the calls into the system. The main aim of the research work is to find the optimum number of input server connections while minimizing the number of rejected requests according to a specific maximum number of expected calls in a specific time interval, i.e. at a peak hour. Model is based on key segments composing the call and severs system (ordinary, lamer and dummy caller model, Gaussian distribution of calls, mechanisms of accepting and rejecting calls, management of input connection capacity, random call triggering, etc.). Using them in simulator gives a way to find an optimal solution or manually or automatically by automated simulation runs with incrementing/decrementing the number of input connections into the system. The article also presents an automatic analysis of simulation runs and a statistical final report, which includes a conclusion on the results obtained in different scenarios.