A globally optimised multipath routing algorithm using SDN

Abstract

The Software Defined Network (SDN) model promises the delivery of a network architecture capable of handling the demands of current and future applications more efficiently than the current distributed network architecture. SDN gains this ability by moving to a logically centralised control plane. The centralised network controller has up to date information on both the network topology and the flows using the network. In this work we use the information already available at the network controller to create a globally optimised Per-Packet multipath routing algorithm. An optimal Per-Packet multipath routing algorithm may split a flow unequally between different paths. Current SDN capable hardware is not able to split flows in an unequal fashion while still remaining scalable. To overcome this limitation, we also propose a stochastic flow splitting mechanism capable of dividing a flow into any number of fractional components while offering better scalability than current methods. To analyse the performance of our proposed system, the GEANT network topology is used. Under heavy traffic load, our system shows a 90% improvement in a flow's received throughput when compared to OSPF and ECMP.