A Class of Candidate Selection Algorithms for Hybrid IP/SDN to Tolerate Single Bidirectional Link Failures with Budget Constraints

In hybrid Internet Protocol(IP)/Software Defined Network (SDN) only few of the IP nodes are replaced with SDN switches to reduce cost and implementation complexity. These SDN switches are called as candidate switches. In this paper, we study the performance of hybrid IP/SDN network to tolerate bidirectional link failures. We first obtain the candidate switches using two candidate selection algorithms (CSAs) referred to as Greedy CSA and Minimum CSA. Next, we study Greedy and Minimum CSAs by considering only one shortest path between any two nodes in the network. Later, we extend these CSAs by considering all shortest paths between all nodes in the network. Moreover, we address the problem of deploying additional candidate switches if the constraints on budget (Number of candidate switches) are relaxed. The performance of the considered CSAs are evaluated in terms of average repair path length and maximum link utilization on various real world network topologies.