Performance comparison of QoS routing algorithms applicable to large-scale SDN networks

In Software Defined Networking (SDN) the network control plane is decoupled from the data plane and centralized at programmable controller. One of the advantages of centralized control is possibility to efficiently implement traffic engineering mechanisms, that are still lacking in today's backbone networks due to instability of distributed routing protocols and high management complexity. In this paper, we analysed suitability of different routing algorithms for dynamic setting up of performance guaranteed traffic tunnels in backbone SDN networks. Two routing constraints were considered: bandwidth and path delay. Beside bandwidth rejection ratio, which is commonly used as performance indicator for QoS (Quality of Service) routing algorithms, in the context of SDN low computational time is pointed out as important requirement.