In a controller-based network, what happens to network decision-making logic?

In a controller-based network, what happens to network decision-making logic?

• A. It remains distributed.
• B. It is moved to the centralized controller.
• C. It is removed entirely.
• D. It runs on edge devices.

Answer: (B)

The decision-making logic is centralized in a controller. In a controller-based network, the control plane—the part that decides how traffic should flow—is moved to a single, centralized controller, while the forwarding devices (switches/routers) merely execute the controller’s instructions. This separation lets the controller have a global view of the network, making it easier to implement policies, optimize paths, and adapt quickly to changes. When the network needs a different route, the controller computes it and pushes new forwarding rules to the devices. The other scenarios don’t fit this model: keeping decisions distributed resembles traditional networks; removing the logic isn’t feasible; and having edge devices run the decision logic would undercut the centralized programmability the setup relies on.

The decision-making logic is centralized in a controller. In a controller-based network, the control plane—the part that decides how traffic should flow—is moved to a single, centralized controller, while the forwarding devices (switches/routers) merely execute the controller’s instructions. This separation lets the controller have a global view of the network, making it easier to implement policies, optimize paths, and adapt quickly to changes. When the network needs a different route, the controller computes it and pushes new forwarding rules to the devices. The other scenarios don’t fit this model: keeping decisions distributed resembles traditional networks; removing the logic isn’t feasible; and having edge devices run the decision logic would undercut the centralized programmability the setup relies on.