TCP Throughput Achieved by a Folded Clos Network Controlled by Different Flow Diffusion Algorithms

Abstract

A folded Clos network (FCN) is the topology often used for data center networks. Its performance depends on the flow diffusion algorithm executed at the input/output switches. Several algorithms that diffuse flows more equally between links than conventional random routing have been proposed in the past. It is expected that those algorithms prevent the TCP (transmission control protocol) throughput from decreasing due to traffic congestion. However, it is unclear whether these flow diffusion algorithms are significantly effective for avoiding throughput degradation of a TCP flow compared with conventional random routing. This paper investigates the effectiveness of flow diffusion algorithms for TCP throughput through packet-level computer simulation. The results confirm that flow diffusion algorithms can efficiently reduce the number of TCP flows, the throughputs of which are degraded.