On transport daemons for small collaborative applications over wide-area networks

A number of science applications employing collaborative computations require transport methods that guarantee end- to-end performance at the application level. Throughputs achieved by the traditional transport methods are limited to single default best-effort IP paths, which are often insufficient for the application tasks. In this paper, we present a measurement-based approach that utilizes application-level daemons at the collaborating sites to enhance the transport performance by utilizing multiple quickest paths. This method is based on a linear approximation of the effective bandwidth, and is computationally efficient and analytically tractable under fairly general conditions. We implemented and tested this method at Internet nodes, and the experimental results show significant performance improvements over the default TCP.