A Multipath Flow Routing Approach for Increasing Throughput in the Internet

In the current Internet, hotspots arise because traffic tends to be routed along shortest hop paths sharing common links, leading to congestion on these links and underutilization on others. Current routing protocols are not able to exploit the path redundancy that exists in the Internet. To improve overall throughput and network utilization, we propose a multipath flow routing overlay system, coupled with network sensors that provide realtime information about overlay links, to distribute traffic more efficiently over the network. In particular, we focus on improving the throughput performance of large file transfers over TCP/IP-based internets. Files are dynamically split into multiple flows, which are then distributed over the network by the multipath flow routing overlay. We have implemented such a routing overlay using the Click modular software router and studied its performance on the Emulab network emulation testbed. We present performance results, which show that the multipath routing overlay can dramatically increase TCP throughput under a variety of network scenarios.