SDN Controller Adaptive Path Calculation

The SDN controller performs preliminary actions by obtaining flow entry capacity information from switches in advance and calculating threshold values before performing path calculations. This allows the controller to proactively identify and exclude switches that would become overloaded, ensuring that subsequent path calculations automatically avoid problematic switches without adding complexity to the calculation process itself.

The patent applies local quality by treating switches with different flow entry capacities differently. Instead of using a uniform assumption for all switches, the controller obtains specific capacity information for each switch and calculates individualized threshold values. This allows the path calculation to adapt to local conditions at each switch, excluding only those switches that would become overloaded while maintaining others in the calculation.

The patent changes the parameter used in path calculation from a static assumption of infinite capacity to a dynamic threshold value based on actual switch capacity. The controller obtains flow entry capacity information from switches and transforms this into threshold values that are then used to filter switches during path calculation. This parameter change enables adaptive path selection without requiring complex real-time monitoring of actual flow entry usage.

The patent introduces an intermediary mechanism in the form of threshold values that mediate between the SDN controller and the actual switch capacity. Instead of directly monitoring and managing flow entries on switches, the controller uses these calculated thresholds as an intermediary layer to indirectly control and optimize path selection. This intermediary approach simplifies the controller's role while still achieving performance optimization.