Test Papers / Previous Question Papers of IGNOU CS68 Computer Networks December 2005

BACHELOR IN COMPUTER APPLICATIONS
Term-End Examination

December, 2005

CS68 (S) : COMPUTER NETWORKS

Time: 3 hours
Maximum Marks: 75

1. (i) What is a computer network ? List the three applications of computer network and explain its features. (4)

(ii) List the four factors that determine whether a network is LAN, MAN or WAN and explain. (4)

(iii) Explain the basic principles of CSMA/CD. How is it different from a Token ring protocol ? (5)

(iv) Suppose transmission channels become virtually error free. Is the data link layer still needed ? (4)

(v) What are piggybacking and pipelining ? What are their advantages ? Discuss. (3)

(vi) Compare bridges with gateways. Explain their functioning using suitable diagram. (6)

(vii) How does an ATM network work ? Explain through an appropriate diagram. (4)

2. (i) Describe the bandwidth limitation of B-channel and D-channel. List the two basic types of ISDN services. Describe channel capacity in B-channel & D-channel and its applications. (9)

(ii) Explain the features of the following routing protocols : (6)
(a) RIP
(b) OSPF

3. (i) Answer the following questions:
(a) Differentiate between broadband and baseband system.
(b) What is DNS and its purpose ? Give any two domain names along with their meanings.
(c) Discuss advantages and disadvantages of transparent bridges.

(ii) How is connection established and released in a transport layer ? Discuss it with a timing diagram. (6)

4. (i) Make a comparison between virtual circuit and datagram. (6)

(ii) Write pseudocode for source routing bridge. (3)

(iii) Differentiate between (6)
(a) Hubs and Switches
(b) Analog data and Digital data

5. (i) Describe the characteristics of physical layer and ATM adaptation layer. Also show the ATM protocol model. (7)

(ii) What is the difference between N-ISDN and B-ISDN ? Discuss five applications of ISDN. (8)