Network Controller for Multi-Tenant Isolation

The patent introduces a network controller as an intermediary device that sits between the management plane and the switching elements. This controller abstracts the complexity of managing shared switching elements by providing a centralized control mechanism that handles user isolation, access control lists, and forwarding logic without requiring direct low-level configuration of each component. The controller maintains a global view of the network state and translates high-level management decisions into specific switching element configurations.

The patent segments the control plane into multiple virtual controllers, each responsible for a specific user or tenant. This segmentation allows each user to have their own isolated control instance that manages their forwarding logic and access control lists independently. The virtual controllers communicate with the physical switching elements through a standardized interface, enabling multiple users to share the same physical infrastructure while maintaining logical isolation. Each virtual controller maintains its own view of the network state for its assigned user, preventing cross-user interference.

The network controller implements self-service mechanisms by automatically discovering and maintaining the global network state through interactions with switching elements and management applications. The controller proactively collects topology information, monitors network conditions, and updates its internal state model without requiring manual intervention. This automated state maintenance reduces the knowledge burden on network operators, as the controller handles the complexity of tracking network changes and translating them into appropriate configuration decisions.