A network-centric TCP for interactive video delivery networks (VDN)

Interactive video streaming requires very low latency and high throughput. Traditional latency based congestion control algorithm performs poorly in fairness. This results in very poor video quality to adaptive video streaming. Software defined networks (SDN) enables us to solve the problem by designing a network controller in the routers. This paper presents a SDN-centric TCP where sending rate of the network is calculated from the network rather than the host. Routers along the path uses a proportional integral (PI) controller to calculate the sending rate in order to reduce the queuing delay. The routers also divide the available throughput fairly among the flows. The network based controller is found more effective than the sender/receiver based controller in reducing latency and providing fairness. NC-TCP has been designed for interactive video delivery network (VDN) where the interactive video flows compete among themselves. Such differentiated service obviates the need for TCP-friendliness. We have implemented NC-TCP in Linux kernel. We have evaluated NC-TCP in Mininet for an interactive video streaming application. Our experimental results shows that NC-TCP outperforms delay-based congestion control in an interactive VDN.