Here I am giving you question paper for B.E Information Technology course offered by Anna university in a word file attached with it so you can get it easily.

Anna University B.E Information Technology paper

ANNA UNIVERSITY – TIRUNELVELI

QUESTION PAPER CODE: E 095

B.E/B.Tech DEGREE EXAMINATIONS, NOVEMBER/DECEMBER 2009

FIFTH SEMESTER

CSE
CS1302 – COMPUTER NETWORKS
(REGULATIONS 2007)
(COMMON TO IT)
PART – A
1. Which of the OSI layers handles each of the following
(a) Dividing the transmitted bit streams into frames
(b) Determining which route through the subnet to use
2. What are the advantages of wireless media over wired media?
3. Compare the performance of 1 – persistent and non-persistent CSMA protocols in terms of channel utilization under varying loads.
4. What is the level of reliability provided by the simple parity scheme in error detection?
5. Datagram organization of the network is similar to that of the services offered by the postal department. Justify this statement.
6. What is the significance of the IP addresses of the format 127.x.y.z?
7. Reliability is not required for a data communication. Even then transport layer is required in TCP/IP networks. Why?
8. What types of applications prefer UDP rather than TCP?
9. What are the limitations of symmetric cryptosystems?
10. Differentiate between FTP and TFTP protocols.

PART – B
11. (a) (i) Illustrate the functioning of an optical fiber transmission system in terms of the emitter, fiber and detector.(8)
(ii) Describe the functioning of a microwave based communication system (4)
(iii) Discuss the advantages and disadvantages of microwaves over radio waves (4)
Or
(b) (i) Mention the design principles that were applied in arriving the seven- layer model of the ISO/OSI reference model. (6)
(ii) Explain the seven layers of the ISO/OSI reference model in detail with a neat diagram. (10)

12. (a) (i) A bit stream 10011101 is transmitted using the standard CRC method. The generator polynomial is x3 +1. Show the actual bit string transmitted. Suppose the third bit from the left is inverted during transmission. Show that this error is detected at the receiver’s end. (8)
(ii) Explain the following framing techniques with examples:
(1) Character count (2)
(2) Flag byte with byte stuffing (2)
(3) Starting and ending flags , with bit stuffing (2)
(4) Physical layer coding violations (2)
Or
(b) (i) Discuss the limitations of stop and wait protocol (4)
(ii) Explain the window maintenance at the sender and receiver in the sliding window protocol. (6)
(iii) Compare and contrast the go back –n and selective repeat variants of the sliding window protocol. (6)
13. (a) (i) Explain the distance vector routing protocol with an example(10)
(ii) Mention the advantages and disadvantages of distance vector routing protocol (6)
Or
(b) (i) Explain the link state routing algorithm with an example. (10)
(ii) Mention the advantages and disadvantages of link state routing protocol. (6)
14. (a) (i) Suppose that TCP congestion is set to 18KB and a timeout occurs. How big will the window be if the next four transmission bursts are all successful? Assume that the maximum segment size is 1KB(4)
(ii) Consider the effect of using a slow start on a line with a 10 msec round trip time and no congestion. The receiver window is 24KB and the maximum segment size is 2 KB. How long does it take before the first full window can be sent? (6)
(iii)Explain the improvement suggested by Karn in deciding the time out period in TCP. (6)
Or
(b) (i) If the TCP round-trip time,RTT,is currently 30 msec and the following acknowledgements come in after 26,32 and 24 msec,respectively what is the new RTT estimate using the Jacobson’s algorithm? Use a = 0.9. (6)
(ii) A TCP machine is sending full windows of 65,535 bytes over a 1-Gbps channel that has a 10 msec one-way delay. What is the maximum throughput available? What is the line efficiency? (4)
(iii) Explain the three way handshake protocol used by TCP to establish the connection (6)
15.(a) (i) Explain the process of establishing the connection with the web server, fetching a web page and displaying it using HTTP (8)
(ii) Discuss the SMTP protocol by describing a typical client server interaction (8)
Or
(b) Explain the principles, organization and provided services of DNS in detail (16)