A Simple Multipath OpenFlow Controller using topology-based algorithm for Multipath TCP

Multipath TCP, or MPTCP, is a widely-researched mechanism that allows a single application-level connection to be split to more than one TCP stream, and consequently more than one network interface, as opposed to the traditional TCP/IP model. Being a transport layer protocol, MPTCP can easily interact between the application using it and the network supporting it. However, MPTCP does not have control of its own route. Default IP routing behavior generally takes all traffic through the shortest or best-metric path. However, this behavior may actually cause paths to collide with each other, creating contention for bandwidth in a number of edges. This can result in a bottleneck which limits the throughput of the network. Therefore, a multipath routing mechanism is necessary to ensure smooth operation of MPTCP. We created smoc, a Simple Multipath OpenFlow Controller, that uses only topology information of the network to avoid collision where possible. Evaluation of smoc in a virtual local-area and a physical wide-area SDNs showed favorable results as smoc provided better performance than simple or spanning-tree routing mechanisms.