Rajiv Gandhi Proudyogiki Vishwavidyalaya 2008-3rd Sem M.C.A Computer Aplications .(ester) ,., - Question Paper

MCA-305
M.C.A.(Third Semester) EXAMINATION,Dec.,2008
COMPUTER NETWORKS
(MCA-305)
Time : 3 Hours
Maximum Marks : 100
Minimum Pass Marks : 40

Note : There are 5 Units. Attempt 1 ques. from every Unit. All ques. carry equal marks.

Unit - I
1.(a) elaborate the advantages and disadvantages of fiber optics over copper wire ?
(b) Differentiate ranging from the subsequent :
(i) OPCM and PCM
(ii) FDM and TDM
(c) elaborate the major functions of the Data Link layer of ISO-OSI reference model ?
Or
(a) elaborate the reasons for using layered protocols ?
(b) If the bit rate of a signal is 2000 bps, how many bits can be transmitted in one m sec, ?
(c) Show that the efficiency of slotted ALOHA is double of pure ALOHA.

Unit - II
2.(a) The message 11010110111110 arrivals using generator polynomial x4 + x + 1. discuss whether it
is accurate or not.
(b) Write down the procedure of one-bit sliding window protocol. Also discuss what will happen
when 2 users begin transmitting the message to every other simultaneously.
Or
(a) Generate the Hamming codeword of the dataword : 10110001.
(b) Using 4-bit sequence number, what is the maximum size of the send and receive windows for
every of the subsequent protocols ?
(i) Stop-and-wait
(ii) Go-Back-N
(iii) Selective-Repeat

Unit - III
3.(a) Differentiate ranging from bridges and gateways.
(b) discuss token ring MAC sublayer data frame format.
(c) define the principle of operation of the subsequent MAC method as used in LANs :
(i) CSMA/CD
(ii) Control Token
Or
(a) define the IEEE 802.4 standard protocol and its frame format.
(b) discuss the subsequent :
(i) FDDI
(ii) DGOB

Unit - IV
4.(a) By using Dijkstra algorithm, calculate the shortest path ranging from the node a and d in the
subsequent graph :

(b) discuss the subsequent :
(i) The optimality principle
(ii) Multicasting

Or
(a) explain the Link state routing with suitable example.
(b) discuss the token bucket algorithm.
(c) Differentiate ranging from TCP and UDP.

Unit - V
5.(a) discuss cipher block chaining and chipher feedback mode. Which 1 is more efficient and how?
(b) Using e = 13, d = 37 and n = 77 in the RSA algorithm, encrypt the message "Good" using the
values of 00 to 25 for letters A to Z.
Or
(a) elaborate all the possible number combination of inputs in a 7-by-3, S-box ? What is the
possible number of outputs ?
(b) discuss the subsequent :
(i) DNS
(ii) Digital signature

b    7    c

4 h

Attachment: rajiv-gandhi-proudyogiki-vishwavidyalaya-2008-m-c-a-computer-aplications-4194-1.JPG

Earning:   Approval pending.