Computer Networks - Dec 2015

Electronics & Telecom Engineering (Semester 7)

TOTAL MARKS: 100
TOTAL TIME: 3 HOURS (1) Question 1 is compulsory.
(2) Attempt any four from the remaining questions.
(3) Assume data wherever required.
(4) Figures to the right indicate full marks.

Solve any one question from Q1 and Q2

1 (a) Draw OSI reference model and explain functions of data link layer and presentation layer.(7 marks) 1 (b) A channel has data rate of 4kbps and propagation delay of 20ms. Calculate the frame size if the channel efficiency is 50%.(7 marks) 1 (c) What is backbone network? What are its types? Explain with necessary diagrams.(6 marks) 2 (a) Draw TCP/IP protocol suite. List with example addresses present at every layer.(7 marks) 2 (b) Explain flow control in data link layer.(7 marks) 2 (c) Explain Basic service set and Extended service set in WLAN.(6 marks)

Solve any one question from Q3 and Q4

3 (a) Compare IPv4 and Ipv6.(6 marks) 3 (b) List the various protocols giving their significance at network layer.(6 marks) 3 (c) Explain the various classes of IP addressing with their respective ranges. Also list the range of private IP addresses and the standard mask for first three classes of IP addresses.(6 marks) 4 (a) Draw and explain IPv4 frame format.(6 marks) 4 (b) Write short note on DHCP.(6 marks) 4 (c) Give the classification of commonly used Unicast Routing protocols and explain Distance Vector Routing protocol with an appropriate example.(6 marks)

Solve any one question from Q5 and Q6

5 (a) Draw the TCP frame format. Explain the use of flags.(6 marks) 5 (b) Explain the reliability, delay, jitter and bandwidth requirements for the internet applications E-mail and video conferencing.(6 marks) 5 (c) Explain in brief port numbers and socket address.(4 marks) 6 (a) Explain 3 way/step handshaking for connection establishment and 4 step connection termination.(6 marks) 6 (b) Explain the features of Stream Control Transmission Protocol (SCTP).(6 marks) 6 (c) Draw and explain UDP frame format.(4 marks)

Solve any one question from Q7 and Q8

7 (a) What are the main responsibilities of Application Layer? Explain in brief.(6 marks) 7 (b) Explain DNS in Internet.(6 marks) 7 (c) Explain the RSA algorithm. Also explain its limitations.(4 marks) 8 (a) Compare symmetric and asymmetric cipher.(6 marks) 8 (b) Write short note on electronic mail system.(6 marks) 8 (c) Explain the Substitution cipher with its advantages and disadvantages.(4 marks)