Effective Flow Table Space Management Using Policy-Based Routing Approach in Hybrid SDN Network

Software-defined networking makes forwarding devices easier to manage and provides centralized control. Because of the centralization, a network administrator can programme the devices cheaply. Network administrators make attempts to convert their entire network into SDN-compatible switches. A good balance of SDN and legacy switching functions can lead to a successful network scenario in network architecture. In this study, a hybrid network scenario is provided in which the external boundary forwarding devices of the service provider network are replaced with SDN devices. Still, the other internal forwarding devices continue to operate traditionally. The benefits of both SDN and legacy network design are combined, allowing the network administrator to reap the benefits of both. The network architecture employs a policy-based routing algorithm that takes advantage of free IP addresses from the free IP pool. The technique enables efficient use of available flow table space, which is critical in SDN architecture due to the small flow table size. The algorithm's efficiency is assessed using performance metrics such as network path stretch, throughput, latency delay, and so on, compared to traditional SDN controllers such as OpenDayLight, NOX, and POX. According to the experimental results, the suggested approach outperforms specific similar state-of-the-art techniques in the hybrid SDN domain.