Hybrid Incremental Deployment of HSDN Devices

Hybrid-software-defined networks (HSDN) have opened up an enormous range of functionality and benefits for network users and administrators. Many of these functionalities have been extensively studied and addressed over the past few years. However, it is not a panacea as it brings with it many design challenges to get a robust and reliable network. In this paper, we focus on one of the SDN challenges: the incremental deployment of SDN devices in HSDN treated as an optimization problem. In this context, we developed a mixed integer linear programming (MILP) and a genetic algorithm (GA) considering a hybrid deployment scheme that combines current incremental deployment and replaced deployment techniques. The proposed strategy determines which traditional devices will be replaced by SDN devices, which SDN devices will be added to the network changing its topology, and how the traffic will be routed. Consequently, the aim is to minimize the deployment cost, minimize the routing cost and maximize the traffic controlled by the SDN network simultaneously. The experiments show that the proposed hybrid deployment approach is promising compared to current techniques, and the GA is more robust and scalable than the MILP as the traffic volume increases.