Design of a NFV Traffic Engineering Middlebox for Efficient Link Failure Detection and Recovery in SDN Core Networks

Due to the increasing demand for critical services and industrial applications, Software Defined Networking (SDN) has become the most ideal and efficient solution for core networks. This is due to the central intelligence, programmability and simplified network management offered by SDN. However, the unpredictable nature of network environments in terms of node or link failures, makes core networks vulnerable to service disruption. Several techniques were proposed to cope with single or multiple link failures in SDN networks, but they present major drawbacks in terms of delay in the detection and recovery of failed links, or a significant overhead at the controller incurred from constantly processing control packets from the switches to detect failures. This paper proposes to introduce a dedicated traffic engineering Middlebox for link failure detection and backup path computation. The introduction of the Middlebox requires rethinking the architecture of SDN and shifting the link failure detection and backup computation functions to the Middlebox. The Middlebox employs the Bidirectional Forwarding Decision (BFD) routing protocol for fast link failure detection and uses Dijkstra's Open Shortest Path First (OSPF) and the Bellman-Ford algorithms to compute the shortest recovery path with the highest available bandwidth. The proposed solution was extensively tested in the Mininet platform. The results of the experiments were compared to that of the conventional SDN LLDP-based technique. The results show that the proposed Middlebox significantly performs better and achieves faster link failure detection than LLDP. We also observed faster link failure recovery, improved link downtime, and reduced controller overhead.