Recent advances in computer networking have introduced a new technology paradigm for future communication,
the Software Defined Networks (SDN). A central software program, called SDN controller, manages the overall
network behavior. Into SDN the control and data planes are decoupled, network intelligence is logically centralized.
The controller can add, update, and delete flow entries, both reactively in response to packets and proactively with
predefined rules. In addition, SDN enables fast reaction to security threats, granular traffic filtering, and dynamic
security policies deployment.