CoSwitch: A Cooperative Switching Design for Software Defined Data Center Networking

Software Defined Network (SDN) provides flexibility and agility for customizing the Data Center Network (DCN), which is essential element for the full support of multitenancy. In the current DCN infrastructure, physical switchs are able to support SDN protocols, such as OpenFlow. However, due to the limited resources of embedded CPU and on-chip memory size, physical OpenFlow switch suffers from considerable overhead for handling frequent control plane workload. Worse still, great numbers of mice flows existing in DCN real-life trace generate huge control plane workload, causing the control plane of physical switch to be the serious performance bottleneck. In this paper, based on the performance profiling of virtual and physical switches, we present CoSwitch, a novel switching design for DCN. CoSwitch leverages virtual switch on the server, which has powerful control plane, to cooperate with physical switch, which has high-speed data plane. A close-loop workload balancing mechanism is designed to distribute different kinds of workload into different types of switches in the most efficient way. Through real-life trace experiments on physical testbed, CoSwitch is demonstrated to achieve both scalable control plane and data plane. Without specialized hardware requirement, CoSwitch mitigates the bottlenecks of OpenFlow. Keywords-DCN, SDN/OpenFlow, Mice Flow, Control Plane Workload, Virtual Switch, Physical Switch