Flow Diffusion Algorithms Based on Local and Semi-Local Information for Folded Clos Networks

Folded Clos networks (FCNs) are often employed as a topology for data center networks. When an FCN is applied to a data center network, traffic congestion on links must be avoided to enable high throughput data transmission. To avoid congestion, flows need to be uniformly diffused between the links. Therefore, this paper investigates two algorithms that nearly uniformly spread flows in FCNs. The first algorithm is executable with information that is locally obtainable at the source of a flow. This method is further divided into two versions. One version reroutes some existing flows, while the other does not perform rerouting. The second algorithm runs with semi-local information, which can be obtained via communication between the source and the destination switches. The processing overhead for these algorithms is small because global information is unnecessary. The paper evaluates the presented algorithms and conventional random routing. The result clearly shows the advantage of the presented algorithms.