INT20CN Computer Networks

Tutorial #2

1. What is a protocol? How does the use of the word "protocol" in computer networking differ from its meaning in other contexts?

2. What is a protocol data unit (PDU)?

3. What tasks are performed by the transport service module (or layer)? Name at least two.

4. What is the major function of the network service module (or layer)?

5. In the example from the lecture (slide 6), the transport service layer (or module) split the application data unit into two TPDUs. Give reasons why it might do this.

6. In the lecture, it was claimed (slide 6) that the network service module did not have to guarantee reliable delivery of packets. Why not?

7. Harder: Is it possible that the network layer could additionally split a TPDU into two or more NPDUs? Give reasons why it might do this, and suggest the likely format of the resulting NPDUs.

Extra Notes