Minimizing downtimes: Using dynamic reconfiguration and state management in SDN

Software-Defined Networks (SDN) are constantly evolving and so is their software. One of the key advantages of SDN over traditional networks is the ability to rapidly develop and deploy new features. However, updating them often requires restarting the SDN controller and causes network downtime. In addition to such planned updates, unforeseen, accidental downtime is also a risk for SDN networks. While commercialized SDN controllers are adding mechanisms to deal with both planned and accidental downtime, they still are not competitive with conventional approaches, which typically use redundant hardware and special software to address these problems. In this paper we investigate how these two challenges to SDN can be addressed with dynamic reconfiguration and show how the state of the network can be managed by reconfiguration. Finally, we present a proof-of-concept implementation of our approach.