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Reg No.: Name:

APJ ABDUL KALAM TECHNOLOGICAL UNIVERSITY
FIRST/THIRD SEMESTER MCA DEGREE EXAMINATION, JULY 2018

Course Code: RLMCA 201
Course Name: COMPUTER NETWORKS

Max. Marks: 60 Duration: 3 Hours
PART A
Answer all questions, each carries 3 marks Marks
1 What is meant by a protocol? Enlist the three elements of protocol. (3)
2 What is the purpose of conditional GET message in HTTP? (3)
3 What is meant by handshaking? Which protocol implements handshaking (3)
mechanism?
4 What is subnet masking? Enlist the default mask used in classful addressing. (3)
5 What is the difference between a hub and a switch? (3)
6 List out all the services offered by the link layer. (3)
7 How mobility is ensured in the same IP subnet? (3)
8 How can collisions be avoided in the presence of hidden terminals? (3)
PART B
Answer six questions, one full question from each module and carries 6 marks
Module I
9 a) What are the different layers of Internet model? (4) b) Which are the new layers
implemented by the OSI reference model? Quote its (2) functionality.
OR
10 a) What are the components of basic communication system? (3) b) What is meant by
QoS? How it is implemented? (3)
Module II
11 a) What is the difference between persistent HTTP with pipelining and persistent (3)
HTTP without pipelining? Which among these is default connection in HTTP 1.1
b) Mention the difference between recursive and iterative queries in DNS. (3) OR
12 a) Why does email application use Mail Access Protocol even when SMTP is (2) already

implemented for mail sending?
b) What is the purpose of using MIME in e-mail application? (4)

Module III
13 Demonstrate the following flow control mechanisms with suitable example-Go- (6)
Back-N and Selective Repeat.
OR
14 a) Describe the UDP segment Structure with diagram. (3) b) How is congestion
control handled by TCP? (3)
Module ۷

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