A Combination Tree-Based Method for Link Failure Protection in Hybrid Sdn Networks

Software-Defined Networks (SDNs) have emerged as significant frameworks for enhancing network flexibility. Currently, the migration from legacy IP networks to pure SDNs promotes the development of hybrid SDNs. However, the inevitable link failures will damage the network reliability. Therefore, this paper focuses on upgrading the legacy routers to SDN switches with minimal deployment overhead for protecting against all link failures. First, we propose a Combination Tree-based SDN candidate selection method, which constructs the node selection relationship through link reliability and employs pruning strategies to enhance search efficiency. Through experiments on multiple network topologies, the results demonstrate that our proposed algorithm can effectively reduce the number of required SDN switches compared to existing approaches while ensuring the same protection effect. Additionally, the advantage becomes more significant as network connectivity increases, which shows that this method can better utilize network connectivity to achieve efficient SDN deployment.