Future high speed networks will carry traffic from a variety of applications, including distributed computing/database applications. The primary motivation to use high speed networks for this application class is to achieve very low latencies, and more importantly, to obtain guarantees on the delay bounds at the application level. This project will investigate application level performance in high speed networks for this application class. The objectives of this research are to (1) characterize traffic from this application class using actual traces, (2) determine application-level QoS requirements for this application class, (3) translate the end-to-end application-level QoS requirements to network level per node QoS (for instance, cell-level QoS for switching nodes in ATM networks), and (4) assess the effectiveness of existing techniques (both at the network as well as the application level) to guarantee QoS requirements for this application class. Analytical and simulation techniques assisted by measurements will be used in this research. The significance of this research will be its contributions to the fundamental understanding of the interaction between distributed computing/database applications and high speed networking architectures and protocols.