Abstract: A simulator for simulating the performance of an intelligent is described. The simulator includes. a module for simulating any IN-typical event sequences (traffic simulator) according to the rules of traffic theory, and a module for the event-oriented simulation of the service control point (SCP simulator) using process models, The simulator also includes. an arrangement for exchanging data between the modules; an arrangement entering and storing the network configuration, communication service specification, and other simulation parameters, and for transferring them to the correct modules; and an arrangement outputting and/or storing the simulated data. Modules are also provided for simulating the SS7 signaling system, taking into account the functionalities of service relay points SRP and overload protection mechanisms within the IN. The simulation modules communicate in a file mode using transfer files or are linked in an online mode by a shared organization program: the online simulator.