Real-Time Services in Myrinet Based Clusters of PCs

High performance modular switch-based interconnection networks have become popular for both embedded computer systems and clusters of PCs/ workstations. However, these networks have typically no, or only limited, support for real-time communication. Applications like computerized visualization and multimedia streaming need support from the network to guarantee bandwidth and latency. In this thesis, a method is presented of how to get guaranteed hard realtime services for periodic tra c in a wide range of switched networks, which is veri ed by analysis and experiments on Myrinet where important parameters have been characterized. The solution does not require any additional hardware or modi cation of the switches, i.e., it is purely based on software implementation in the end notes. The solution includes reservation of network links and bandwidth sharing using Time Division Multiple Access (TDMA). With reservation of network links and TDMA, blockage is avoided in the network and the worst case latency for a packet is kept short. Nor does any deadlock occur, which makes the system very stable without any constraints on the topology.