Link Failure Emulation with Dijkstra and Bellman-Ford Algorithm in Software Defined Network Architecture (Case Study: Telkom University Topology)

In Telkom University, the topology used does not have backup link for campus internal network in case of link failure because the topology is still based on interVLAN where each switch only has one path to switch core. Data packets cannot be delivered from source to destination if there is a link failure on the path. Based on the problem, it is proposed a new architecture which is Software Defined Network (SDN) that can overcome the link failure by configuring the controller in order to move to alternative links that have been provided with OpenFlow. This architecture separates the control plane and data plane, so it is centralized and programmable. To look for alternative links when a link failure occurs, the shortest path algorithm is Dijkstra and Bellman-Ford algorithms. The test parameters performed in this research are functionality to determine whether the two algorithms can determine the path or not, and convergence time to find out how long it takes to form the path from source to destination. Scenario of the test is done before and after the link failure occurs by using Ryu as controller and Mininet as emulator. Based on the results of the tests conducted, it was found that Dijkstra and Bellman-Ford algorithm can be applied well on link failure emulation in accordance with the scenario and topology used in the test. In addition to convergence time parameters obtained that Dijkstra algorithm is superior compared to Bellman-Ford algorithm. The difference gained in both scenarios has a value that is not so great the difference.