Increasing Resilience of OpenFlow WANs Using Multipath Communication

Software-Defined Networking (SDN)/OpenFlow is recently recognized as an emerging technology for network virtualization and programmability. In an OpenFlow network, forwarding (data) planes (i.e., OpenFlow switches) are distributed and remotely controlled by a so-called network controller, which centralizes the network´s control functions. The centralized control model of SDN has been proven to be applicable in various deployments ranging from datacenter, campus networks to wide area networks (WANs). In the OpenFlow-based networks, the communication channel between the network controller and switches, which is defined in the scope of OpenFlow specification, plays the most important role. In this paper, we argue that in the state-of-the-art specification establishing one path between a switch and controller potentially decreases the resilience of OpenFlow WANs. Therefore, we propose to use multiple paths for each switch-controller communication and discuss applicable multipath technologies.