Abstract:Software defined networking may need to frequently update their data planes to optimize network performance due to flow dynamics or traffic load transfer. Most existing strategies first determine a target route configuration based on the current network flow status. Then, flows in the network are updated to the target route configuration. However, since the low operation speed of ternary content addressable memory (TCAM) for flow tables update, route updates usually gets long delay. Moreover, route updates delay will get longer in a large or topology frequently changed network. According to recent works, most flows have short durations and the total flows intensity may vary after a certain time period. Hence, the new route configuration may be inefficient if the route update delay takes too long. In this study, the real time route update for SDN is addressed and a delay satisfied route selection and updating scheme (DSRSU) is proposed. Different from most existing studies, DSRSU jointly considers the flow route selection in the control plane and route update scheduling in the date plane to reduce the route update delay. More specially, only a subset of flows is chosen for route updates in route selection. To further improve the update speed, an update dependency graph is established to explore the scheduling order of the flows during update scheduling. Simulation results demonstrate DSRSU can largely reduce the route update delay compared with previous route update strategies while maintaining a similar route performance.