This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5). The bottleneck for the transferring data at very high speeds often turns out to be the end-system performance. In the absence of definitive knowledge about the workload at the receiving end-system, the sender's transmission rate often overshoots the critical bottleneck rate of the receiver. This typically results in oscillations between the extremes and poor performance. To optimize the performance of the transport protocols and achieve the important flow control functionality, it is important to estimate the receiving end-system effective bottleneck rate. In this project we will use modeling and active analysis of the end-system to estimate this rate. We will develop queueing network models for representing the different multicore and multiprocessor end-systems running different types of workloads. We will develop a software tool to be integrated with existing transport protocols. We will carry out experimental analysis for different types of end-systems with different configurations and workloads. We will apply and extend methods that have been proposed to address the limitations of queueing network models for performance analysis of computer systems with bursty workloads and correlated service times. The software tool will be made available to the research community to analyze and optimize distributed applications and systems. The research project will provide a framework to train graduate and undergraduate students in both analytical and experimental methods, and develop knowledge and intuition about next generation computer systems and distributed applications.
