M.C.A. DEGREE EXAMINATION, NOVEMBER/DECEMBER 2017.
Third Semester
Paper IV COMPUTER NETWORKS
2 90234-A
Time 3 Hours Max. Marks 70
SECTION — A
Answer any FIVE of the following. 6 30 Marks)
Each question carries 6 marks.
1. Differentiate Packet Switching and Circuit-Switching with an example.
2. Illustrate the structure of Electronic Mail.
3. Discuss about Congestion control in detail.
4. Explain about Wireless Lan MAC sub layers
5. For n devices in a network, what is the number of cable links required for a mesh,
ring, bus and star topology?
6. How does error detection and correction techniques are helpful in networks?
7. Explain TCP header in detail.
8. How does HTTP and SMTP are similar?
SECTION — B
Answer any questions from each Unit. 10 40 Marks)
Each question carries 10 marks.
UNIT I
9. Explain in detail about Electronic Mail System.
Or
10. Consider a scenario of network delay-one packet one hop: Suppose that a user at
one end of Canada sends a l-Mbit file to a remote server on the other end over a
data link operating at 64 kbps. Assume that we are using a fiber optic link with a
propagation rate of the speed of light, approximately 3*108 m/sec, and that the
distance is 4800 km. Ignore any processing or queuing delays. What is the overall
network delay, i.e. time to transmit the file?

UNIT II
11. Analyse how Multiplexing and Demultiplexing work. Exemplify.
Or
12. Justify how TCP protocol is used in establishing a reliable data transfer?
UNIT III
13. Illustrate the functionality of the router. Explain in detail about hierarchical
routing.
Or
14. Explain various network service models. Also illustrate the routing process in the
internet.
UNIT IV
15. Explain in detail about ATM Logical Connections and ATM Cells.
Or
16. How do you manage network systems? Discuss about SMPV1 protocol.