3.9 Exercises

1. Why do you think a pseudo header was defined in TCP and UDP?

2. Develop the logic for a routine which can be called by a task in a non-preemptive system to hand over control to the scheduler. The handover should occur if there are no events to process and/or if the task has determined that it has consumed enough CPU time.

3. Draw an architectural diagram of a driver implementing a device-dependent layer and a device-independent layer. Outline the functions of each layer.

4. Outline all the protocols required for a TCP/IP end node implementation, and show the interaction between them via a diagram.

5. Provide an example of a callback function and the sequence of operations for its invocation. Also, detail the functionality of the callback function.