1. What are the SAP addresses in FM radio broadcasting?
SAP addresses are the FM frequencies, like FM 91.4.
2. What is the difference between connectionless communication and connection-oriented communication?Refer to lecture notes and book.
3. Why is there a need to support multi-level addressing?Identify different machines and different applications.
4. What are two reasons for using layered protocols?Refer to lecture notes.
5. Which of the OSI layers handles each of the following: a) Breaking the transmitted bit stream into frames. b) Determining which route through the subnet to use.a) DL layer. b) Network layer.
6. A system has an n-layer protocol hierarchy. Applications generate messages of length M bytes. At each of the layers, an h-byte header is added. What fraction of the network bandwidth is filled with headers?
(n*h)/M
7. When transferring a file between two PCs, (at least) two acknowledgement strategies are possible. First, the file is chopped up into packets, which are individually acknowledged by the receiver, but the file transfer as a whole is not acknowledged. Second, the packets are not acknowledged individually, but the entire file is acknowledged when it arrives. Discuss the two approaches.
Use the first approach when network is not very reliable. It is much easier and efficient to recover packets than the whole file.
8. List two advantages and two disadvantages of having international standards for network protocols.
Advantages: everyone obeys standards, hence user choice of multiple vendors to buy from. Disadvantages: may take a lot of time for companies to agree on standards, it would also be difficult to modify later.
