A comprehensive analysis on control plane deployment in SDN: In-band versus out-of-band solutions

Nowadays Software-Defined Networks paradigm becomes more popular in computer networking society, so that it is applied in various networked environments. Although the literature has articulated several benefits of this approach in terms of improved flexibility and performance, the major question of how connectivity between control and data planes in regard to dedicated or shared links between these planes has not received much attention. Diversity of SDN applications leads to complicating the selection of In-Band or Out-of-Band control plane strategies. In this paper, a comprehensive comparison between these two state-of-the-art strategies is investigated. First, several involving factors based on previous works are addressed. Then some experimental evaluations in regard to other important metrics are carried out using Mininet emulator. Analyses show that selecting the best control plane deployment strategy depends on various key parameters such as deployment feasibility, costs, security considerations, link failure challenges, network bootstrapping time and other experimental considerations.