Comparison of Routing Algorithms with Static and Dynamic Link Cost in SDN

There are several routing algorithms that can be used in the context of Software Defined Networking (SDN), where a logically centralized controller obtains the global view of the network and network state information, makes the routing decisions, and installs them to the switches in the selected paths. Comparing the performance of the existing routing algorithms under realistic simulation scenarios and understanding the factors that impact their performance are very important for their adaption in practice. Accordingly, we implemented several existing routing algorithms using RYU SDN controller and evaluated their performance on Mininet emulator. We considered three categories of Routing Algorithms with Static Link Cost (RA-SLC), Dynamic Link Cost (RA-DLC), and Dynamic Link cost with Minimum Interference (RA-DLCMI) under both the idealistic case assuming the availability of accurate network state information (NSI) and the practical case where the NSI is collected periodically and has some inaccuracy. Our experimental results showed that both RA-DLC and RA-DLCMI outperformed RA-SLC in terms of throughput and the number of accepted flows while there was no significant difference between RA-DLC and RA-DLCMI. We also observed that periodic collections caused inaccuracies in NSI and negatively affected the performance of all algorithms.