An Effective Flow-Rule-Reducing Algorithm for Flow Tables in Software-Defined Networks
Ming-Hua Cheng, Wen-Shyang Hwang, Yan‐Jing Wu, Cheng‐Han Lin, Jhen-Siang Syu · 2020
The flow table of an OpenFlow switch plays a crucial role in software-defined networks (SDNs), which have novel network architecture. To achieve fast lookup in flow tables, the OpenFlow switch uses ternary content-addressable memory to design flow tables. However, this memory has limited capacity for flow tables and some flow rules may be redundant, which can cause a congestion problem in flow tables. The congestion problem also influences the performance of the entire network. This paper proposes an effective flow-rule-reduction (EFRR) algorithm for reducing the number of flow rules for an OpenFlow switch and improving the performance of an SDN. The proposed EFRR algorithm favorably trades-off computation time and compression rate and reduces the number of flow rules efficiently. According to simulation results obtained using a Mininet controller, the EFRR algorithm results in a higher compression rate and a shorter computation time.