Improving QoS in real-time internet applications: from best-effort to Software-Defined Networks

Real-Time Online Interactive Applications (ROIA), e.g., multiplayer online games and simulation-based e-learning, are emerging internet applications that make high Quality of Service (QoS) demands on the underlying network. These demands depend on the number of users and the actual application state and, therefore, vary at runtime. Traditional networks have very limited possibilities of influencing the network behaviour to meet the dynamic QoS demands, such that most ROIA use the underlying network on a best-effort basis. The emerging architecture of Software-Defined Networking (SDN) decouples the control and forwarding logic from the network infrastructure, making the network behaviour programmable for applications. This paper analyses ROIA requirements on the underlying network and describes the specification of an SDN Northbound API that allows ROIA applications to specify their dynamic network requirements and to meet them using SDN networks.