Access to communication networks is increasing rapidly. The increase access to these networks results in delays and at times loss of data. At times of peak traffic or when trunks or nodes are down, very important customers\u27 communications requirements are not met. One way to combat this problem is to prioritize the network and provide different levels of grade of service (GOS) for each priority. Call preemption provides an effective method of obtaining different levels of GOS. This research seeks to design the best circuit switch communications network preemption model for the DoD by analyzing previously developed preemption algorithms. Four simulation network models are developed. The grades of service per priority are obtained as the network capacity decreases and as the calls generated in node 0 increases. The analysis of preemption network models is based on the grade of service, average number of preemptions, and average network bandwidth. The networks are simulated under the same input parameters. The analysis showed that preemption can significantly lower the grade of service for high priority customers in a congested network. The best configuration preemption model depends on the bandwidth flexibility of the network and the goals of the communications network organization