Abstract. Many simulation-based performance studies of interconnection networks are carried out using synthetic workloads under the assumption of independent traffic sources. We show that this assumption, although useful for some traffic patterns, can lead to deceptive performance results for loads beyond saturation. Network throughput varies so much amongst the network nodes that average throughput does not reflect anymore network performance as a whole. We propose the utilization of burst synchronized traffic sources that better reflect the coupled behavior of parallel applications at high loads. A performance study of a restrictive injection mechanism is used to illustrate the different results obtained using independent and non-independent traffic sources.