Lightweight and Fast Coordinated Update Algorithm for Hybrid SDN Networks

Abstract

Hybrid software-defined networking (SDN) networks are intermediates between traditional networks and SDN networks. However, since the hybrid control planes are structurally different from the single control plane, updating the hybrid SDN networks lacks effective techniques. In this paper, by utilizing the segment routing (SR) mechanism to update hybrid SDN networks and formalize the application of SR during updates, we propose a cooperative consistency update algorithm that can coordinate SR, two-phase commit techniques. The algorithm is capable of preserving consistency with low overhead and excellent applicability. When a network requires updating, the algorithm leverages the SR mechanism to stitch a new path using the available path segments; thus, flows can use the new path immediately. If the update cannot be completed with the SR mechanism alone, the algorithm can utilize the two-phase commit technique to update the nodes through duplication. Notably, our experiments based on real topologies indicate that, compared to prior techniques, the proposed algorithm can greatly reduce the TCAM overhead.