Realizing the Quality of Service (QoS) in Software-Defined Networking (SDN) based Cloud infrastructure

Software-Defined Networking (SDN) is a new network paradigm that virtualizes network infrastructure by decoupling the control and data plane logic of traditional network devices, creating a dynamic, flexible, automated and manageable architecture. SDN is implemented through a protocol known as OpenFlow that lets administrators select the path through which data will flow through a network. Network-wide data flow control gives administrators the power to define network flows that match the connectivity requirements of end stations and address the specific needs of discrete user communities. For example, an administrator might select network bandwidth, path latency or other criteria as the optimal communication path for a specific data flow. We have implemented a system called QoS Controller, Q-Ctrl, for programmatically attaining users´ required QoS constraints in a SDN based Cloud infrastructure. Q-Ctrl system is able to execute in a virtual overlay network via open vSwitch (OVS), physical network infrastructure equipped with SDN Controller, or simulated SDN environment via Mininet. In this paper, we detail i) the design and implementation of Q-Ctrl system, ii) how the network QoS for virtual machines are maintained through Q-Ctrl, and iii) a case-study on how a video streaming application leverages the Q-Ctrl system to achieve QoS in an SDN based Cloud infrastructure.