A ring-based single-link failure recovery approach in SDN data plane

Software-defined networking (SDN) enables a network to be programmable, which makes it easy for the network to recover from failures. Upon failure, network can revert to operational state through preprogrammed recovery strategies. However, most of existing recovery approaches do not consider storage resource consumption. Nowadays the network scale and the number of flows increase greatly, numerous flow entries are required in case of failures, but the Ternary Content Addressable Memory (TCAM) that stores flow entries is very expensive and capacity-limited. Therefore, it is significant to reduce the consumption of backup resource. In this paper, we propose a ring-based single-link failure recovery approach (RSFR) to achieve failure recovery with less flow entries. A ring is selected from the network to act as a shared backup path, based on the ring, we plan all backup paths and design switches' flow tables to improve the utilization of flow entries required for failure recovery, thus network can recover from failures with less flow entries. Simulation results show that the proposed approach has a better performance in backup resource consumption, and recovery delay is less than 50ms.