Switched Ethernet is a dominating technology in local area networks, and a strong contender in system area networks.
This thesis describes measurements on switched Ethernets, in the context of high speed system area networks with real time requirements. One such system is the ATLAS level 2 trigger, which formed the basis of the measurements. Further on the thesis describes the design, implementation and results from a simulation model of the measured devices.
In general the results indicate that switched Ethernet provides a service close to the ideal for this switch architecture. The devices were found to be near non-blocking and it was possible to prevent packet loss with Ethernet flow control. Some performance anomalies were found, and the thesis emphasises that validation tests are needed in this application since it is beyond normal usage patterns for these commodity products.
A simulation model of the network was developed. It was possible to obtain a quite accurate model of the latency distributions. Packet loss proved to be difficult to model accurately. The lack of a head of line blocking prevention mechanism in the model is thought to be the reason for the packet loss inaccuracies.