Computer Networks - Jun 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.

Answer any one question from Q1 and Q2

1 (a) Draw ISO-OSI model and explain in brief function of each layer.(8 marks) 1 (b) Compare Coaxial Cable, Twisted pair cable and Fibre optic cables.(6 marks) 1 (c) Explain in brief physical address, network address and port number.(4 marks) 10 (a) Draw TCP header. Explain function of each field.(6 marks) 10 (b) How congestion affects network performance? Also explain the difference between flow control and congestion control.(6 marks) 10 (c) What is socket address? Explain.(4 marks)

Answer any one question from Q11 and Q12

11 (a) Explain Telnet and FTP in detail with respect to server and client communication.(8 marks) 11 (b) What is DNS? Explain the components of DNS system.(6 marks) 11 (c) What is the function of SMTP and POP-3 protocols in E-mail system?(4 marks) 12 (a) Distinguish between public key and private key algorithm. State the advantages of RSA algorithm.(8 marks) 12 (b) What are the main responsibilities of Application layer? Explain in brief.(6 marks) 12 (c) What is URL and what are its components?(4 marks) 2 (a) Draw and explain typical cable TV system. How cable video signal and internet data can be send over the same cable.(8 marks) 2 (b) What is DSL? Explain any two types of DSL.(6 marks) 2 (c) Compare circuit switching and packet switching network.(4 marks)

Answer any one question from Q3 and Q4

3 (a) Explain Go Back-N ARQ and Selective Repeat ARQ protocol.(6 marks) 3 (b) What is framing concept in Data Link Layer? Explain in details.(6 marks) 3 (c) How does token ring LAN operate?(4 marks) 4 (a) Explain the following:
i) 1-persistent CSMA
ii) Non-persistent CSMA
iii) P-persistent CSMA(6 marks) 4 (b) Draw HDLC frame format. Write function of each field.(8 marks) 4 (c) Compare the data rates for standard Ethernet, Fast Ethernet, Gigabit Ethernet and Ten-Gigabit Ethernet.(2 marks)

Answer any one question from Q5 and Q6

5 (a) What is VLAN? How does it work? Explain with necessary diagram.(6 marks) 5 (b) What is Frame Relay? Explain the different frame formats used in frame relay.(10 marks) 6 (a) Write short notes on:
i) Gateway
ii) Hub
iii) Routers(6 marks) 6 (b) Explain the functions of different layers in Bluetooth. Also explain the different types of frame formats used in Baseband Layer.(10 marks)

Answer any one question from Q7 and Q8

7 (a) What services are provided by network layer to transport layer?(6 marks) 7 (b) Briefly define subnetting. How do the subnet mask differ from a default mask in classful addressing?(6 marks) 7 (c) Why is ARP request broadcast but ARP reply unicast?(4 marks) 8 (a) Show the format of typical IP datagram header and explain.(6 marks) 8 (b) What are different static routing algorithms? Explain any one in detail.(6 marks) 8 (c) What is DHCP? How does it work?(4 marks)

Answer any one question from Q9 and 10

9 (a) Explain the different Quality of Service parameters. Also write about transport layer service primitives.(6 marks) 9 (b) Explain connection establishment and connection releasing with respect to transport layer.(6 marks) 9 (c) What are the duties of transport layer? List the services provided by transport layer to upper layers.(4 marks)