SDN Policy Control for Dynamic Application Service Chains

The patent introduces an SDN controller as an intermediary component that bridges the gap between the data plane (packet forwarding) and control plane (policy control). The SDN controller receives service chain information from PCRF, translates it into forwarding rules, and distributes these rules to network devices. This intermediary architecture enables virtualization and flexibility while maintaining simplified policy management through centralized control.

The patent implements dynamic service chain selection and forwarding rule generation based on real-time context information. The PCRF determines application service chains dynamically according to subscriber attributes, application types, and network conditions. The SDN controller then dynamically translates these service chains into forwarding rules and updates network devices in real-time, enabling the network to adapt flexibly to changing service requirements while maintaining stable operation through automated control.

The patent performs deep packet inspection and service chain determination in advance through the PCRF before traffic actually flows through the network. The PCRF proactively analyzes application traffic, identifies service requirements, and determines the appropriate service chain based on context information. This preliminary action allows the SDN controller to pre-compute and distribute forwarding rules to network devices, so that during actual traffic forwarding, no time-consuming inspection is needed - packets are simply routed according to pre-established rules, significantly reducing processing time.