Design of virtual gateway in virtual software defined networks

Network virtualization is a technique that abstracts the underlying physical infrastructures into multiple isolated networks. Currently, network virtualization based on Software-Defined Networking (SDN) has attracted interests from industry and academia to utilize limited network resources by using benefits of SDN. SDN has useful features such as programmability, flexibility, and agility. In order to virtualize networks in SDN, a network hypervisor intercepts and modifies OpenFlow messages so that it provisions multiple virtual networks, virtual Software-Defined Networks (vSDNs). However, existing SDN-based network hypervisors do not provide an easy-to-use method to connect a created vSDN with external networks. It limits the usefulness of vSDNs. To resolve this problem, we propose a virtual gateway for external connectivity in vSDN. The proposed virtual gateway is implemented using ONOS virtualization subsystem. The virtual gateway is able to provide external connectivity and other useful network functions such as firewall, traffic shaping, and load-balancing. To demonstrate the feasibility of virtual gateway, we evaluate round trip time and deployment time to show a connectivity and overhead of the virtual gateway deployment.