problem 1:
Coaxial cable is a two-wire transmission system, what is the advantage of connecting the outer conductor to ground?

problem 2:
Describe the two layers: LLC & MAC, and how are they different from what is available in the TCP/IP protocol? Why do we need these two extra layers for a LAN?

problem 3:
Suppose that data are stored on a 1.4-Mbyte floppy diskettes that weight 30 g each. Suppose that an airliner carries 10,000 kg of those floppies at a speed of 1000 km/h over a distance of 5000 km. What is the data transmission rate in bits per second of this system ?

problem4:
What is the main difference between TCP and UDP ?

problem 5:
Imagine that you have trained your dog to carry a box of three data storage tapes. (When your disk fills up, you consider that an emergency). These tapes each contain 7 gigabytes. The dog can travel to your side, wherever you may be, at 18 km/hour. For what range of distances does the dog have a higher data rate than 155 Mbps ATM line ?

problem 6
When transferring a file between two computers, (at least) two acknowledgment strategies are possible. In the first one, the file is chopped up into packets , which are individually acknowledged by the receiver, but the file transfer as a whole is not acknowledged. In the second strategy, the packets are not acknowledged individually, but the entire file is acknowledged when it arrives. Discuss the two approaches.