Answer:
1.
Role of communication layer:
-it has the responsibility of transferring information among network controlled devices.
-it provides up to date view of the state of the network to SDN controller which shows that a new device has being added to the network as well as the link that was attached being non-existent.
2.
Role of network wide state management layer:
-it is responsible for the controller having the network's state information
-it also helps in the making of ultimate control decisions.
c
role of network control application layer:
- It is responsible for the reading and also the writing of the state of the network as well as flow tables which are in the layer of state management.
- It also notifies of changes such as state-event change. this helps to take actions with regards to the event notification.