APPLICATIONS
Term-End Examination
December, 2007
CS-68 : COMPUTER NETWORKS
Time : 3 hours Maximum Marks : 75
Note : Question number 1 is compulsory. Answer any three questions from the rest.
1. (a)What do you mean by Data Communication ? Write the characteristics on which effectiveness of data communication system depends. (5)
(b) Define point to point network and explain any three topologies for point to point subnet. (4)
(c)Explain different categories of network that is LAN, WAN and MAN. Also write one protocol name used for each type of network.(9)
(d) Define different sublayers of Data Link Layer. Also write the services provided by Data Link Layer.(5)
(e) Name different LAN architectures. (2)
(f) Explain Stop and Wait protocol with the help of a suitable diagram.(5)
2. (a) Differentiate between Hub and Switch.(5)
(b) Explain the function of a modem. What are the modulation techniques used in modems ?(5)
(c) Explain five different traffic control mechanisms in networks. (5)
3. (a) Enlist the differences between Virtual Circuit and Datagram Subnet.(6)
(b) Discuss the need of multiplexing. Also explain upward and downward multiplexing with diagram.(5)
(c) Why does congestion occur in data networks ?(4)
4. (a) Explain the process how ATM protocol works.(5)
(b) Write the advantages of small and fixed size cells.(4)
(c) Define Data rate and Signal rate. An analog signal carries 4 bits per signal. If 1000 signals elements are sent per sec, find the bit rate.(6)
5. (a) Explain Ethernet protocol.(5)
(b) Explain the characteristics of Broadband Coaxial Cable.(5)
(c) Explain the advantages of ISDN.(5)