High middle ages is the answer
Answer and Explanation:
Messages flow across an SDN controller's:
Northbound APIs:
• Messages which help in read/write state of the network and developing flow tables within the
state management layer.
• Notifications for the state-change events.
• The interaction between the controller and network control applications is done through the
northbound interface.
• Network control applications send messages to the controller.
Southbound APIs:
• Messages which help for the up-to-date view of the network's state like message for the
attached link has gone up or down, new devices are joined the network, or indications of the
device is up or down.
• Controller's southbound interface is the communication among the controller and the controlled
devices. Controlled devices are the recipients of the messages sent form the controller.
Im like 90% sure its a container file
