Switch-Centric Byzantine Fault Tolerance Mechanism in Distributed Software Defined Networks

Supporting byzantine fault tolerance (BFT) in distributed software-defined networks (SDNs) may lead to increased consensus delay and traffic load since all messages should be verified and multicasted among controllers. To address this problem, we propose a switch-centric byzantine fault tolerant (SC-BFT) mechanism, in which key BFT functions (e.g., message authentication and comparison) are implemented at the programmable switches. Thus, SC-BFT can accelerate the consensus procedure and mitigate the communication overhead. We implemented SC-BFT at BMv2 using P4. Analytical and simulation results show that SC-BFT provides 80% reduced response time compared to conventional BFT consensus mechanisms with significantly reduced communication overhead.