Abstract
Software Defined Network (SDN) is a new network architecture, which provides its flexible control in order to satisfy the various requirement. This paper shows overview and applications of OpenFlow technology, which is a standard interface designed for SDN. We first explain a standardized OpenFlow switch and protocol specification, and then show its application for datacenter networks. At last, we introduce Trema, which is a framework for developing OpenFlow contollers, and RISE, which is a nation-wide OpenFlow testbed network.