Scheduling is an important aspect of Integrated Service Networks (ISNs) and plays a major role in determining the quality of service (QoS) a particular application receives. In this paper, we discuss the main design issues related to scheduling and provide a framework for the analysis of different scheduling algorithms for ISNs.Detailed simulation experiments, using different network parameters, including switch buffer sizes, inter-arrival rates, service rates, and network link capacities, were conducted. Our results show that simple scheduling algorithms, such as FCFS, are not adequate to support real-time QoS when the network load is heavy. The results also show that more complex algorithms may be required to provide an acceptable level of service guarantees.