Improving the performance of cooperating TCP connections

Many applications use multiple concurrent TCP connections. In such cases, both the application and the network benefit from the collection of TCP connections cooperating rather than competing with each other for scarce resources (e.g., router buffers). This paper shows how the performance of an application that uses multiple concurrent TCP connections can be improved by forcing all the connections through rate controllers that shape the TCP traffic. The rate controller limits the bandwidth used by any connection, allows information about bandwidth and contention to be shared among connections, and breaks up packet trains. Simulation results show that rate control improves the performance of single-client/multiple-server connections in a LAN (parallel file system case) by 15-100%, and multiple-connections/single-server connections in a WAN by up to 50%.