A 64 node Clos network has been simulated using the commercial OPNET simulation package [9]. A model of the DS link and the STC104 switch has been developed within the Macramé project for this simulator. Results from simulation and measurement have been compared and are shown in Figure 9, which shows the latency distribution for 64 byte packets and random traffic at 50% load. The majority of packets pass through the network without being queued, corresponding to the peak at 12 s. It can be seen that the agreement between simulation and measurement is very good.
Figure 9: Simulated and measured latency distributions for a 64 node Clos network
Figure 8: Network throughput versus packet transmission overhead for a 128 node
Clos network