Download DU (University of Delhi) B-Tech 3rd Semester 1567 Data Communication and Computer Networks Question Paper

Download DU (University of Delhi) B-Tech (Bachelor of Technology) 3rd Semester 1567 Data Communication and Computer Networks Question Paper

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Roll No.
S. No. onuestion Paper 7 : 1567
Unique Paper Code : 2341302 . F-3
Name of the Paper : Data Communication and Computer Networks
' Name of the Course : B.Tech. in Computer Science
Semester : III
- Duration :3 Hours A ? Maximum Marks : 75
(Write your Roll No. on the top immediately on receipt of this question paper.)
Attempt all the questions.
1. ? Write the iayer in 081 Model perform the fellowing functions : ' ? 2
(a) Route ~(ietermination 3
(6) Flow control
(C) ' Mechanical and electrical interfece ,
(d) ' Reliable proeess-to-prooeesidata.trmsportation
? (e) Reassembly of data packets-
(f) ? Error?rcorrection and retransmission.
~ 2. Explain the following: 3
' (1) Does the'Nyqui-st th?eorem bit rate agree with'the intuitivel-bit 'rate described?in baseband
transmissiOn? . ? ?- ' z 3
PTO.

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(2)
(3)
(4)
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The signal-to-noise ratio is often given in decibels. Assume that SNRdB = 36 and the
channel bandwidth is 2 MHz. Calculate the theoretical channel. 3
An analog signal carries 4 bits per signal element. If 1000 signal elements are sent per
second, ?nd'the bit rate. . 2
Differentiate between binary PSK and Quadrature PSK. . 4
Biie?ydescribe the following :
' (a)
(b)
(C)
' (a)
(b)
- (6.).
Three phases required for the actual communication in a circuit-switched'network. 3
If there are no setup or teardown phases, how are the packets routed to their destinations
in a datagram network ? ? , I - 3
Draw the pulse diagram for the bit stream 10111000101] for the following ehcoding?
technique: .? h ?. ? 2 6
. (i) NRZ-L
(ii) Manchester ?
(iii) Di??eiential'Mancvhcster. .7
How do multiple senders share the common transmissiohmedia inra network. List three
techniques commonly used for this purpgslem _ J i _ . . 2+3
Explain bridgejouter and gateway.. ' , , , . I ? 3
Suppose a?eomputer is moved from one building to another within acatm?us Does the
physical address need to change ? Does the IP address need to change ?2 Does it make
' a difference. if the computer is a laptop ? Justify your answer. 3

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(a)
(b)
(C)
(3)
Explain header ?eld in IP protocol with diagram.
1567
4
'An organization has been assigned the network address : 140.25.0.0 and it needs to
.create a set of subnets that support upto? 25 hosts on each subnet. What is the subnet
mask you would use to do this ?
3
What is the maximum possible number of such subnets in the given network ? The use
of special address must be avoided.
'2
What is the difference between a connection-oriented service and a connectionless
service ? For eachof the following tell whether, it might be a connection oriented service,
a connectionless service, both or neither :
(I)
(ii)
(iii)
(a) ?
(b)
-(1)_? FTP
Connection establishmient ?
Data transmission
.Conhectjon release.
Write the port number of the. following protocols :
(iz') HTTP .
(ii!) TELNET
(iv) VSMTP.
What is DNS and how it resolves IP Address from URL ?-
2+3
Rite.

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8.
,1567
Write short notes on any six of the following :
(1 )
(2)
(3)
(4)
(5)
(6)
(7)
(8.)
(9) -
( 4
ARQ
Selective repeat ARQ
TDM
FSK
Hamming code
CRC
Packet switching
Exponential back of algorithm
(Coaxial Cable Standards.
1567
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