Resilience of SDNs based On active and passive replication mechanisms

Software-Defined Networking is a new paradigm that allows the development of innovative network management applications and provides a new way to look for the resolution of problems which exist throughout the Internet today. In order to simplify the task of managing the network most of SDN architectures uses a centralized network management approach. However, such approach raises, among other problems, the issue of a single point of failure, that can compromise the proper functioning of the network. A proven method to achieve a higher level of network resilience is to use a replication technique. The aim of this work is to investigate: (1) how different replication techniques relate to each other, (2) how each one performs on the task of providing resilience to a SDN, and (3) which technique is the most suitable for different scenarios. Replication techniques are mainly classified in two types: passive and active replication. In the case of passive replication, the client connects with only one controller that processes the requests and updates the other controllers. In active replication, the client connects with multiple controllers that process the request. Our results show that replication is a suitable way to increase resilience in a SDN and to build these services for networks using SDN is straightforward and much less complex.