Consistent route update in software-defined networks

This paper addresses the flow table update consistency issue that exists in the Software Defined Networking (SDN) enabled networks. We propose a simple flow table update mechanism that provides consistency with zero packet loss guarantee. Our proposed flow table update mechanism does not require any packet modification by leveraging the usage of existing SDN technology. In our proposal, the switch update sequence is the key factor. Switches affected by the update procedure are classified into different categories according to their forwarding behavior. A specific update sequence is defined according to the dependency among different switches categories. The performance of our proposal has been examined by an algorithm level simulation and an OpenFlow-based system level testbed.