Multimedia transmission over software defined networks

Abstract

The transmission of video traffic on computer networks requires rapid route adaptation. On traditional networks, switching protocols, such as the Rapid Spanning Tree Protocol, are not fast enough to prevent visible video degradation when a route needs to change at the MAC layer. Also, manual intervention may be required from the network administrator to configure all the affected network devices. Since most of the traditional network devices use closed configuration protocols, proprietary hardware and Ethernet Switching standards, it was required to find a way to modify the network programmatically using software. Software Defined Networking (SDN) satisfies this requirement. This project proposes a testbed using SDN to control the flow of multimedia transmission. Devices on the network communicate with the SDN controller, where all the network decisions take place. Requests by the devices are then passed to the intended switch as flow entries, using the OpenFlow protocol. The testbed simulates adaptive video streaming, by transmitting two video streams with different resolution on two different multicast addresses. The receiving hosts receive only the requested stream, depending on a request from the controller, the host or from the network device to which the host is attached, and depending on traffic conditions. The testbed demonstrates how using SDN, the packet header and the flow of a stream can be modified automatically in response to network conditions. This is shown when a video stream using a unicast address is received by a standby PC when the link to the host is clown. The project shows that through SDN, network traffic can be modified programmatically and relatively fast without any user or administrator intervention. Additionally, it confirms the importance of simulation software in developing SDN applications. Simulation software offers development cost reduction and the possibility to use the same code as on real network.