An openflow testbed for the investigation of software defined networking

Abstract

Enterprise wireless networks need to support different protocols to provide a wide range of services to the end user. Video streaming is one such popular service that is continuously in demand by wireless users. Wireless vendors offer solutions for video steaming services, but these solutions are proprietary, leading to a vendor lock-in, where the administrator cannot do much to improve or adapt to particular network needs. This inevitably leads to a restriction in flexibility. This thesis proposes a testbed using Software Defined Networking (SDN) to test video streaming on a wireless network setup using the OpenFlow (OF) protocol. In this environment, we analysed the effect that handover has on data packets travelling from one host to another through a wireless network. Specifically, we looked at the throughput and packet drops when User Datagram Protocol (UDP) packets are transmitted. Our testbed also shows the effects of handover when streaming a multicast video, particularly when the multicast video is streamed over a wireless connection. Reactive and Proactive switching, two switching mechanisms supported by OpenFlow arc compared on this testbed. Results proved that Proactive switching exhibited fewer packet drops than Reactive switching. This resulted in better data reception by the wireless client and also proved that a multicast stream over wireless is achievable, providing a good quality video transmission to the wireless client. Using OpenFlow protocol, we also propose a setup able to provide reliability in terms of connection and a better video streaming reception. This setup implements the concept of bi-casting, where a client is equipped with a secondary wireless network. Through different OpenFlow flows we manage to increase the throughput and cater for any handovers which the client may perform. In relation to the testbed setup, we also discuss the process of using script agents on the Access Points to notify the OpenFlow controller with the current location of the wireless client. Through the use of SNMP, flows are set up in our network so that clients are able to communicate with each other using the SDN architecture. Our results show that OpenFlow is indeed a protocol using the SDN architecture. Our results show that OpenFlow is indeed a protocol capable of changing the concept of networking through packet manipulation and through the ability to write applications that better serve our network.