AMIETE
– CS/IT (OLD SCHEME)
Code: AC12 / AT10 Subject: DATA
COMMUNICATION & NETWORKS
Time: 3 Hours
Max. Marks: 100
NOTE: There are 9 Questions in all.
· Question 1
is compulsory and carries 20 marks. Answer to Q.1 must be written in the space
provided for it in the answer book supplied and nowhere else.
· Out of the
remaining EIGHT Questions answer any FIVE Questions. Each question carries 16
marks.
· Any
required data not explicitly given, may be suitably assumed and stated.
Q.1 Choose the correct or the best alternative
in the following: (2
10)
a.
Which of the following medium cannot be used for star or bus topology?
(A) twisted pair cable (B) coaxial cable
(C)
optical fibre (D) none of the above
b. The data link layer is concerned with the
(A)
Bit transmission function (B)
Packet transmission function
(C) Re-transmission delay (D) Encryption of data
c. In
to how many bands, with a width of 8 mts a coaxial cable, with bandwidth, 300
MHz, be spitted up if the bandwidth of the guard band is 1 MHz.
(A)
30 (B) more than 30
(C) less than 30 (D)
any number
d. If
a number of nodes collides, they back off without transmitting their packets
and try again after a suitable time. This is known as
(A)
end to end propagation
delay
(B) re-transmission delay
(C) phase delay
(D) collision consensus enforcement
e. Which
of the following is a form of peer to peer communication?
(A) Virtual circuit (B) Virtual
circuit
(C) Packet
switching (D)
System network architecture
f. Error
detection and recovery facilities are two main functions of:
(A)
physical layer (B) data link layer
(C) network layer (D) transport layer
g. The
PC network has
(A)
CSMA/CD (B)
MA
(C) CSMA (D) none of the above
h. A
token with no addressing information is known as:
(A)
explicit token (B) empty token
(C) implicit token (D) logical token
i. Additional
nodes can be placed on a bus by adding extra segments connected by a type of
signal amplifier known as:
(A) repeater (B) modem
(C) multiplexer (D) server
j. Standard
Ethernet cable is known as...............base...................
(A) 100, 5 (B)
20,150
(C) 10, 5 (D)
10,100
Answer any FIVE Questions out of EIGHT Questions.
Each question carries 16 marks.
Q.2 a. Draw the block diagram of a General Data
Communication model and explain the function of each block. (6)
b. Differentiate
between OSI reference model and TCP/IP reference model. (6)
c. Explain
any two application layer protocols. (4)
Q.3 a. Explain properties of the following media:-
(i) Coaxial cable
(ii) Optical fiber
(iii) Radio transmission (6)
b. Consider
a 10 Mbps single segment Ethernet LAN having a cable length of 500 meters and a
mean frame length of 500 bytes. Assuming the speed of signal propagation to be
2.0105 km/sec and an
average of e=2.72 contention slots per contention interval. Determine the
channel efficiency. (6)
c. Explain FDDI and its features. (4)
Q.4 a. A signal has four data levels with pulse
duration of 1 ms. Calculate the pulse rate and bit rate. (8)
b. Define Line Coding and explain various
characteristics of Line Coding. (8)
Q.5 a. Write various applications of Frequency
Division Multiplexing. (4)
b. Explain working operation of TDM-T1 carrier
system. (4)
c.
Draw the
architecture of cellular telephone networks. Explain various components. (8)
Q.6 a. The
codeword is received as 1100 1001 01011.Check whether there are errors in the
received codeword, if the divisor is 10101. (The divisor corresponds to the
generator polynomial) (8)
b. Draw
a basic block diagram of ARQ and explain Selective Repeat ARQ method. (8)
Q.7 a. An ATM network uses a token bucket scheme for
traffic shaping. A new token is put in to bucket every 5µs. What is the maximum
sustainable net data rate (excluding the header bits). (5)
b. Compare Transparent and Source Routing LAN
bridges. (6)
c. Explain Quality of Service
parameters in ATM networks. (5)
Q.8 a. Find the sub-network address and the host id
for the following: (8)
|
S.no |
IP address |
MASK |
|
(a) |
120.14.22.16 |
255.255.128.0 |
|
(b) |
140.11.36.22 |
255.255.255.0 |
|
(c) |
141.181.14.16 |
255.255.224.0 |
|
(d) |
200.34.22.156 |
255.255.255.240 |
b. Define
Centralized control of MAC and also discuss the advantages and disadvantages of
Centralized control method of Medium Access Control. (8)
Q.9 a. Compare Virtual Circuit and Datagram subnets
on various parameters. (5)
b. What
is the need of minimum frame size? If frame size is 64 bytes then calculate the
loss of bandwidth for 100 Mbps Ethernet Network? (5)
c. Explain the following:-
(i) MPLS
(ii) Session control protocols (6)