MFUC: Mitigating Transient Congestion for Multi-flow Updating in SDN

Abstract Through the logically centralized control plane, software-defined network (SDN) provides giant convenience for the design of the network strategies, like load balancing, fault recovery, etc. However, when deploying those strategies on the data plane, transient link congestions may occur since the updating process among the distributed switches is asynchronous. To address this issue, we propose a congestion-aware mechanism for multi-flow updating in SDN. We first obtain the real-time traffic size of each flow to be updated through the link monitoring model. Then we use the congestion-aware algorithm to find the potential congested link and construct the dynamic dependency graph of the updating process, to generate the final updating sequence. Finally, the meter table is configured to limit the flow of crucial predecessor nodes that may have congestion deadlocks to mitigate the transient congestion.