The ever increasing demand for bandwidth in computer networking hasled us from the 3Mbps Ethernet of 1976 to todays 1Gbps Ethernet. Thisevolution in Ethernet bandwidth has presented the network vendors withan increasing range of challenges when producing high capacityEthernet switches.
In this thesis we look at the problems related to throughput,scalability and fairness when designing switching fabrics suitable forGigabit Ethernet switches. We study three different topologies, theButterfly, the Double Butterfly and the Hierarchical Clos togetherwith several routing strategies in our quest to find a viablesolution. The study is performed using two IEEE-1355 based test-bedsto build the actual topologies and do measurements.
We draw the conclusion that the Butterfly is the topology that has thebest price/performance ratio while the Double Butterfly is the winnerwhen price is not an issue. Universal routing is necessary to achievefairness in the network. This combined with grouped adaptive routinggives us high throughput without sacrificing fairness. Finally, overcapacity in the network means a lot for the performance anddrastically reduces the differences between the different routingschemes. When a high level of link utilization is necessary a highdegree of over capacity should be considered.