The basic architecture consists of a three layer abstraction:
The Driver Application layer is provided by the specific driver implementation and makes use of the communication services.
The NComm layer provides access points for the application, implements functionality associated with transport and network OSI layers, and passes messages from/to the link layer.
The Link Layer provides bus specific functionality (Serial, Http, Udp, Tcp) and access to native driver APIs.
Driver specific customization is accomplished by providing extensions or implementations of commConfig classes, message classes, and message factory classes generated by the NDriver Wizard.
The workbench has a tool which allows to create NDrivers: 
Select NDriver:
This wizard will let you select which protocols your driver will use:
And it will also propose many options to customize your plugin. Here is a table summarizing the options and their result:
The wizard will create these classes with the principal methods to implement with some comments to help you understand their goal.