In this paper, the effect of communication networks to the distributed simulation has been studied. A cellular network application is simulated on a network of workstations, where an ordinary 10 Mbps. Ethernet LAN has been used as the communication network. The effect of distribution is analysed by using the well known concept of critical path analysis, which requires event traces from real simulations and information about event processing times as well as about their mutual relationships. In order to capture the effect of conservative synchronization, the event traces are collected from parallel simulations instead of sequential. By using event traces and execution times, critical paths are calculated for different numbers of workstations. The use of different configurations reveals the effect of distribution, as well as the scalability of the problem in the distributed environment. The critical path analysis reveals that the cellular network application is quite suitable for distributed simulation when conservative synchronization is used. Good approximations for the execution time can be achieved if the problem is suitably partitioned into different workstations.