Final answer:
A controller communicates with the data plane through Southbound APIs such as NET CONF and Open Flow; D) Southbound APIs is the correct answer.
Step-by-step explanation:
Southbound APIs allows the end-user to gain better control over the network and promotes the efficiency level of the SDN controller to evolve based on real-time demands and needs. Op Flex, Open Flow, and REST CONF are examples of southbound APIs used in networking.
A controller communicates with the data plane by using Southbound APIs such as NET CONF, Open Flow, OpFlex, or One PK. Therefore, the correct answer to this question is D) Southbound APIs (Application Programming Interfaces).Southbound APIs are the interfaces that connect the control plane to the data plane within a network architecture, enabling controllers to manage network devices and traffic.
Protocols like NET CONF provide mechanisms for installing, manipulating, and deleting the configuration of network devices, while Open Flow allows the path of network packets through the network to be determined. These tools are essential for Software Defined Networking (SDN), where the control plane is decoupled from the data plane for more flexible network management.