Computer Networks MCQ's Question Bank

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Computer Networks MCQ's

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Question Bank of UNIT (1 & 5) with answers... 

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Unit-1
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1. Which processes does TCP, but not UDP,
use?
a. Windowing
b. Acknowledgements
c. Both a and b
d. Destination Port
Answer: Option(c)
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2. SMTP is a protocol used in which layer?
a. Application
b. Network
c. Physical
d. Transport
Answer: Option(a)
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3. Terminators are used in which topology?
a. Bus
b. Star
c. Ring
d. token ring
Answer: Option(a)
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4. In which topology, if a computer’s network
cable is broken, whole network goes down.
a. Ring
b. Star
c. Bus
d. token ring
Answer: Option(c)
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5. For large networks, which topology is used?
a. Bus
b. Tree
c. Ring
d. Mesh
Answer: Option(b)
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6. What is the central device in star topology?
a. STP server
b. Hub/switch
c. PDC
d. Router
Answer: Option(b)
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7. In OSI network architecture, the dialogue
control and token management are
responsibility of
a. session layer
b. network layer
c. transport layer
d. data link layer
Answer: Option(a)
-------------------------------------------
8. In OSI network architecture, the routing is
performed by
a. network layer
b. data link layer
c. transport layer
d. session layer
Answer: Option(a)
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9. Which of the following performs
modulation and demodulation?
a. fiber optics
b. satellite
c. coaxial cable
d. Modem
Answer: Option(d)
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10. The process of converting analog signals
into digital signals so they can be processed by
a receiving computer is referred to as
a. modulation
b. demodulation
c. synchronizing
d. Digitizing
Answer: Option(b)
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11. The protocol data unit (PDU) for the
application layer in the Internet stack is? 
a. Datagram
b. Frame
c. Message
d. Segment
Answer: Option(c)
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12. Which protocol does switch use at the
layer 2 for finding MAC address?
a. ICMP
b. UDP
c. ARP
d. TCP
Answer: Option(c)
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13. Which OSI layer adds a trailer during
encapsulation of data?
a. Layer 3
b. Layer 4
c. Layer 2
d. Layer 5,6,7
Answer: Option(d)
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14. Which of the following term describes
PDU encapsulated at Transport Layer?
a. Frame
b. Packet
c. Data
d. Segment
Answer: Option(d)
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15. Which protocol does HTTP (Hyper Text
Transfer Protocol) - use for transferring web
pages at the Transport layer
a. IP
b. UDP
c. TCP
d. ARP
Answer: Option(c)
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16. There are 10 users plugged into a hub
running 10Mbps half-duplex.and a server
connected to the switch running 10Mbps halfduplex as well. Find the bandwidth does each
host have to the server?
a. 100 kbps
b. 1 Mbps
c. 2 Mbps
d. 10 Mbps
Answer: Option(d)
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17. While transferring files between server and
client, if the transmission rates along the path
is 10Mbps, 20Mbps, 30Mbps, 40Mbps. The
throughput is usually
a. 20Mbps
b. 10Mbps
c. 40Mbps
d. 50Mbps
Answer: Option(b)
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18. Which is the additional layer to OSI model
when compared with TCP IP model?
a. Application layer
b. Presentation layer
c. Session layer
d. Session and Presentation layer
Answer: Option(d)
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19. Maximum data transfer rate of the optical
fiber is……….?
a. 50 kbps
b. 1000 kbps
c. 1000 Mbps
d. None of the these
Answer: Option(c)
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20. A list of protocols used by a system, one
protocol per layer, is called ________
a) protocol architecture
b) protocol stack
c) protocol suite
d) protocol system
Answer: Option(b)
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21. Connector RJ-45 contains?
a. Two pins
b. Four pins
c. Eight pins
d. Ten pins
Answer: Option(c)
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22. Which is not the legitimate transmission
directions listed here?
a. Simplex
b. Half Duplex
c. Full Duplex
d. Double Duplex
Answer: Option(d)
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23. Which layer provides interface between
network support layers and user support
layers?
a. session layer
b. data link layer
c. transport layer
d. network layer
Answer: Option(c)
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24. A set of rules that governs data
communication is called
a. Protocols
b. Standards
c. RFCs
d. Servers
Answer: Option(c)
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25. Which one is not a network topology?
a. Star
b. Ring
c. Bus
d. Peer to Peer
Answer: Option(d)
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26. Full form of OSI
a. open system interconnection
b. operating system interface
c. optical service implementation
d. open service Internet
Answer: Option(a)
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27. Identify the non suitable medium for 802.3
ethernet?
a. A thin coaxial cable
b. A twisted pair cable
c. A microwave link
d. A fiber optical cable
Answer: Option(c)
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28. HTTP stands for?
a. Hyper terminal tracing program
b. Hypertext tracing protocol
c. Hypertext transfer protocol
d. Hypertext transfer program
Answer: Option(c)
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29. Find the best suitable topology for large
businesses which must capable to control and
coordinate the operation of distributed branch
outlets?
a. Ring
b. Local area
c. Hierarchical
d. Star
Answer: Option(d)
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30. Which mode of Communication occurs
between a computer and a keyboard.
a. Automatic
b. Half-duplex
c. Full-duplex
d. Simplex
Answer: Option(d)
-------------------------------------------
31.How many layers are present in the Internet
protocol stack (TCP/IP model)?
a. 5
b. 7
c. 6
d. 10
Answer: Option(a)
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32. The number of layers in ISO OSI reference
model is __________
a. 5
b. 7
c. 6
d. 10
Answer: b
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33.Which of the following layers is an addition
to OSI model when compared with TCP IP
model?
a. Application layer
b. Presentation layer
c. Session layer
d. Session and Presentation layer
Answer: d
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34. Application layer is implemented in _______
a. End system
b. NIC
c. Ethernet
d. Packet transport
Answer: a
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35.Transport layer is implemented in _________
a. End system
b. NIC
c. Ethernet
d. Signal transmission
Answer: a
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36.The functionalities of the presentation layer
include ____________
a. Data compression
b. Data encryption
c. Data description
d. All of the mentioned
Answer: d
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37.Delimiting and synchronization of data
exchange is provided by __________
a. Application layer
b. Session layer
c. Transport layer
d. Link layer
Answer: b
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38. In OSI model, when data is sent from device
A to device B, the 5th layer to receive data at
B is _________
a. Application layer
b. Transport layer
c. Link layer
d. Session layer
Answer: d
-------------------------------------------
39.In TCP IP Model, when data is sent from
device A to device B, the 5th layer to receive
data at B is ____________
a. Application layer
b. Transport layer
c. Link layer
d. Session layer
Answer: a
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40.In the OSI model, as a data packet moves from
the lower to the upper layers, headers are
_______
a. Added
b. Removed
c. Rearranged
d. Randomized
Answer: b
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41.Which of the following statements can be
associated with OSI model?
a. A structured way to discuss and easier
update system components
b. One layer may duplicate lower layer
functionality
c. Functionality at one layer no way
requires information from another
layer
d. It is an application specific network
model
Answer: c
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42. The physical layer is concerned with
___________
a. bit-by-bit delivery
b. process to process delivery
c. application to application delivery
d. port to port delivery
Answer: Option(a)
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43. Which transmission media provides
the highest transmission speed in a
network?
a. coaxial cable
b. twisted pair cable
c. optical fiber
d. electrical cable
Answer: Option(c)
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44. Bits can be sent over guided and
unguided media as analog signal by
___________
a. digital modulation
b. amplitude modulation
c. frequency modulation
d. phase modulation
Answer: Option(a)
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45. The portion of physical layer that
interfaces with the media access
control sublayer is called
___________
a. physical signalling sublayer
b. physical data sublayer
c. physical address sublayer
d. physical transport sublayer
Answer: Option(a)
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46. The physical layer provides
__________
a. mechanical specifications of
electrical connectors and
cables
b. electrical specification of
transmission line signal level
c. specification for IR over
optical fiber
d. all of the mentioned
Answer: Option(d)
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47. In asynchronous serial
communication the physical layer
provides ___________
a. start and stop signalling
b. flow control
c. both start & stop signalling
and flow control
d. only start signalling
Answer: Option(c)
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48. The physical layer is responsible for
_____
a) line coding
b) channel coding
c) modulation
d) all of the mentioned
Answer: Option(d)
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49. The physical layer translates logical
communication requests from the
______ into hardware specific
operations.
a. data link layer
b. network layer
c. trasnport layer
d. application layer
Answer: Option(a)
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50. A single channel is shared by multiple
signals by _____
a. analog modulation
b. digital modulation
c. multiplexing
d. phase modulation
 Answer: Option(c)
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51. Wireless transmission of signals can
be done via ___________
a. radio waves
b. microwaves
c. infrared
d. all of the mentioned
Answer: Option(d)
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Unit-II
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1. The two sublayers of a Data Link layer are
a. LLC Logical Link Control Layer
b. MAC Medium Access Control Layer
c. Both A and B
d. Data Layer
Answer: Option(c)
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2. The functions of a Logical Link Layer
(LLC) are
a. Error control
b. Flow control
c. Creating and managing the
communication link between two
devices with the help of the Transport
layer.
d. All the above
Answer: Option(d)
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3. The types of data services offered by an
LLC (Logical Link Control) layer are
a. Connectionless which is fast and
unreliable
b. Connection Oriented which is slow
and reliable
c. Both A and B
d. None
Answer: Option(c)
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4. Choose the Protocols working in the Data
Link Control Layer of OSI model below.
a. ATM (Asynchronous Transfer Mode),
Frame Relay
b. HDLC (High Level Data Link
Control), SDLC (Synchronous Data
Link Control)
c. ARP (Address Resolution Protocol),
IEEE802.3
d. All the above
Answer: Option(d)
-------------------------------------------
5. Which is the protocol that maps varying IP
addresses to the Physical MAC Address of a
machine in a LAN network?
a. ARQ (Automatic Repeat Request)
b. ARP (Address Resolution Protocol)
c. SLIP (Serial Line Internet Protocol)
d. PLIP (Parallel Line Internet Protocol)
Answer: Option(b)
-------------------------------------------
6. Which protocols adopted the standards of
HDLC (High Level Link Control) protocol?
a. X.25 protocol as LAPB (Link Access
Procedure Balanced, V.42 protocol as
LAPM (Link Access Procedure for
Modems)
b. Frame Relay protocol as LAPF (Link
Access Procedure for Frame Relay)
c. ISDN (Integrated Services Digital
Network) protocol as LAPD (Link
Access Procedure on D channel)
d. All the above
Answer: Option(d)
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7. The Dialup connections to access the
internet uses ___ protocol.
a. PPP (Point to Point protocol)
b. X.25 protocol
c. PLIP protocol
d. None
Answer: Option(a)
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8. Automatic repeat request error management
mechanism is provided by ________
a. logical link control sublayer
b. media access control sublayer
c. network interface control sublayer
d. application access control sublayer
Answer: Option(a)
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9. Header of a frame generally contains
a. synchronization bytes
b. addresses
c. frame identifier
d. all of the mentioned
Answer: Option(d)
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10. Which sublayer of the data link layer
performs data link functions that depend upon
the type of medium?
a. logical link control sublayer
b. media access control sublayer
c. network interface control sublayer
d. error control sublayer
Answer: Option(b)
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11. CRC stands for __________
a. cyclic redundancy check
b. code repeat check
c. code redundancy check
d. cyclic repeat check
Answer: Option(a)
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12. When 2 or more bits in a data unit has been
changed during the transmission, the error is
called _____
a. random error
b. burst error
c. inverted error
d. double error
Answer: Option(b)
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13. Which of the following is a data link
protocol?
a. ethernet
b. point to point protocol
c. hdlc
d. all of the mentioned
Answer: Option(d)
-------------------------------------------
14. Which of the following is the multiple
access protocol for channel access control?
a. CSMA/CD
b. CSMA/CA
c. Both CSMA/CD & CSMA/CA
d. HDLC
Answer: Option(c)
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-------------------------------------------
15. The technique of temporarily delaying
outgoing acknowledgements so that they can
be hooked onto the next outgoing data frame is
called ____________
a. piggybacking
b. cyclic redundancy check
c. fletcher’s checksum
d. parity check
Answer: Option(a)
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16. Which of the following uses a very thin
glass or plastic fiber through which pulses of
light travel?
a. Cat 1
b. Optical fiber
c. Twisted pair
d. Coax
Answer: Option(b)
-------------------------------------------
17. When does the station B send a positive
acknowledgement (ACK) to station A in Stop
and Wait protocol?
a. only when no error occurs at the
transmission level
b. when retransmission of old packet in a
novel frame is necessary
c. only when station B receives frame
with errors
d. all of the above
Answer: Option(a)
-------------------------------------------
18. Which consequences are more likely to
occur during the frame transmission in
StopandWait ARQ mechanism?
a. Loss of frame or an acknowledgement
b. Delay in an acknowledgement
c. Normal operation
d. All of the above
Answer: Option(d)
-------------------------------------------
19. Which provision can resolve / overcome
the shortcomings associated with duplication
or failure condition of Stop and Wait
Automatic Repeat Request protocol especially
due to loss of data frames or non reception of
acknowledgement?
a. Provision of sequence number in the
header of message
b. Provision of checksum computation
c. Both a & b
d. None of the above
Answer: Option(a)
-------------------------------------------
20. Which ARQ mechanism deals with the
transmission of only damaged or lost frames
despite the other multiple frames by increasing
the efficiency & its utility in noisy channels?
a. GoBackN ARQ
b. Selective Repeat ARQ
c. StopandWait ARQ
d. All of the above
Answer: Option(b)
-------------------------------------------
21. Which feature of Go Back N ARQ
mechanism possesses an ability to assign the
sliding window in the forward direction?
a. Control Variables
b. Sender Sliding Window
c. Receiver Sliding Window
d. Resending of frames
Answer: Option(b)
-------------------------------------------
22. Which operational mode/s of HDLC
support/s the balanced configuration by
governing point to point link connectivity in
addition to the primary as well as secondary
functions performed by the station?
a. NRM
b. ABM
c. Both a & b
d. None of the above
Answer: Option(b)
-------------------------------------------
23. Which category of HDLC frames
undergoes error and flow control mechanisms
by comprising send and receive sequence
numbers?
a. Uframes
b. Iframes
c. Sframes
d. All of the above
Answer: Option(c)
-------------------------------------------
24. Which type of Sframe in HDLC exhibit the
correspondence of last three bits [N(R)] by
defining the negative acknowledgement
(NAK) number with the code value of '01'?
a. Receive ready
b. Receive not ready
c. Reject
d. Selective Reject
Answer: Option(c)
-------------------------------------------
25. Which among the following represents the
objectives/requirements of Data Link Layer?
a. Frame Synchronization
b. Error & Flow Control
c. Both a & b
d. None of the above
Answer: Option(c)
-------------------------------------------
26. When does the station B send a positive
acknowledgement (ACK) to station A in Stop
and Wait protocol?
a. only when no error occurs at the
transmission level
b. when retransmission of old packet in a
novel frame is necessary
c. only when station B receives frame
with errors
d. all of the above
Answer: Option(a)
-------------------------------------------
27. For pure ALOHA, the maximum channel
utilization is
a. 100%
b. 50%
c. 36%
d. 18%
Answer: Option(d)
-------------------------------------------
28. The program used to determine the round
trip delay between a workstation and a
destination address is
a. Tracert
b. Traceroute
c. Ping
d. Pop
Answer: Option(b)
-------------------------------------------
29. What is the difference between the
Ethernet frame preamble field and the IEEE
802.3 preamble and start of frame Delimiter
fields?
a. 1 byte
b. 1 bit
c. 4 bit
d. 16 bit
Answer: Option(a)
-------------------------------------------
30. Which of the following approaches to
switching share networks resource?
a. Circuit switching
b. Packet switching
c. Both A and B
d. None of these
Answer: Option(b)
-------------------------------------------
31. Determine the maximum length of the
cable (in km) for transmitting data at a rate of
500 Mbps in an Ethernet LAN with frames of
size 10,000 bits. Assume the signal speed in
the cable to be 2,00,000 km/s.
a. 1
b. 2
c. 2.5
d. 5
Answer: Option(b)
-------------------------------------------
32. Let G(x) be the generator polynomial used
for CRC checking. What is the condition that
should be satisfied by G(x) to detect odd
number of bits in error?
a. G(x) contains more than two terms
b. G(x) does not divide 1+x^k, for any k
not exceeding the frame length
c. 1+x is a factor of G(x)
d. G(x) has an odd number of terms
Answer: Option(c)
-------------------------------------------
33. In Ethernet when Manchester encoding is
used, the bit rate is:
a. Half the baud rate.
b. Twice the baud rate.
c. Same as the baud rate.
d. None of the above
Answer: Option(a)
-------------------------------------------
34. In a token ring network the transmission
speed is 10^7 bps and the propagation
speed is 200 metres/micro second. The 1-
bit delay in this network is equivalent to:
a. 500 metres of cable.
b. 200 metres of cable.
c. 20 metres of cable.
d. 50 metres of cable
Answer: Option(c)
-------------------------------------------
35. The message 11001001 is to be transmitted
using the CRC polynomial x^3 + 1 to
protect it from errors. The message that
should be transmitted is:
a. 11001001000
b. 11001001011
c. 11001010
d. 110010010011
Answer: Option(b)
-------------------------------------------
36. The distance between two stations M and N
is L kilometers. All frames are K bits long.
The propagation delay per kilometer is t
seconds. Let R bits/second be the channel
capacity. Assuming that processing delay is
negligible, the minimum number of bits for
the sequence number field in a frame for
maximum utilization, when the sliding
window protocol used is:
a. A
b. B
c. C
d. D
Answer: Option(c)
-------------------------------------------
37. A bit-stuffing based framing protocol uses
an 8-bit delimiter pattern of 01111110. If the
output bit-string after stuffing is
01111100101, then the input bit-string is
a. 0111110100
b. 0111110101
c. 0111111101
d. 0111111111
Answer: Option(b)
-------------------------------------------
38. Station A uses 32 byte packets to transmit
messages to Station B using a sliding
window protocol. The round trip delay
between A and B is 80 milliseconds and the
bottleneck bandwidth on the path between A
and B is 128 kbps. What is the optimal
window size that A should use?
a. 20
b. 40
c. 160
d. 320
 Answer: Option(b)
-------------------------------------------
39. Suppose the round trip propagation delay for
a 10 Mbps Ethernet having 48-bit jamming
signal is 46.4 ms. The minimum frame size
is
a. 94
b. 416
c. 464
d. 512
Answer: Option(c)
-------------------------------------------
40. How many 8-bit characters can be
transmitted per second over a 9600 baud
serial communication link using
asynchronous mode of transmission with
one start bit, eight data bits, two stop bits,
and one parity bit ?
a. 600
b. 800
c. 876
d. 1200
Answer: Option(b)
-------------------------------------------
41. Consider a CSMA/CD network that transmits data at a rate of 100 Mbps (108 bits per second) over a 1 km (kilometre) cable with no repeaters. If the minimum frame size required for this network is 1250 bytes, what is the signal speed (km/sec) in the cable?
a. 8000
b. 10000
c. 16000
d. 20000
Answer: Option(d)
-------------------------------------------
42. Which one of the following statements is FALSE?
a. Packet switching leads to better
utilization of bandwidth resources than
circuit switching.
b. Packet switching results in less
variation in delay than circuit
switching.
c. Packet switching requires more per
packet processing than circuit
switching
d. Packet switching can lead to
reordering unlike in circuit switching
Answer: Option(b)
-------------------------------------------
43. Which of the following statements is TRUE
about CSMA/CD
a. IEEE 802.11 wireless LAN
runs CSMA/CD protocol
b. Ethernet is not based on
CSMA/CD protocol
c. CSMA/CD is not suitable for
a high propagation delay
network like satellite network
d. There is no contention in a
CSMA/CD network
Answer: Option(c)
-------------------------------------------
44. A sender uses the Stop-and-Wait ARQ
protocol for reliable transmission of frames.
Frames are of size 1000 bytes and the
transmission rate at the sender is 80 Kbps
(1Kbps = 1000 bits/second). Size of an
acknowledgement is 100 bytes and the
transmission rate at the receiver is 8 Kbps.
The one-way propagation delay is 100
milliseconds. Assuming no frame is lost, the
sender throughput is __________
bytes/second.
a. 2500
b. 2000
c. 1500
d. 500
Answer: Option(a)
-------------------------------------------
45. In an Ethernet local area network, which one
of the following statements is TRUE ?
a. A station stops to sense the channel
once it starts transmitting a frame.
b. The purpose of the jamming signal is
to pad the frames that are smaller than
the minimum frame size.
c. A station continues to transmit the
packet even after the collision is
detected.
d. The exponential backoff mechanism
reduces the probability of collision
on retransmissions
Answer: Option(d)
-------------------------------------------
46. How many bytes of data can be sent in 15
seconds over a serial link with baud rate of
9600 in asynchronous mode with odd parity
and two stop bits in the frame?
a. 10,000 bytes
b. 12,000 bytes
c. 15,000 bytes
d. 27,000 bytes
Answer: Option(b)
-------------------------------------------
47. The minimum frame size required for a
CSMA/CD based computer network
running at 1 Gbps on a 200m cable with a
link speed of 2 × 108m/s is
a. 125 bytes
b. 250 bytes
c. 500 bytes
d. None of these
Answer: Option(b)
-------------------------------------------
48. Suppose that the one-way propagation delay
for a 100 Mbps Ethernet having 48-bit
jamming signal is 1.04 micro-seconds. The
minimum frame size in bits is:
a. 112
b. 160
c. 208
d. 256
Answer: Option(d)
-------------------------------------------
49. Which of the following statement is False
about the efficiency of the given channel?
a. If we want to send big packets on the
channel, then Stop and Wait is good
choice.
b. If length of packet increases,
efficiency of channel also increases.
c. Distance between sender and
receiver is directly proportional to
efficiency of channel.
d. Efficient might be less if capacity of
channel is high
Answer: Option(c)
-------------------------------------------
50. Consider a link with packet loss probability
of 0.2. What is the expected number of
transmissions it would take to transfer 200
packets given that the stop and wait protocol
is used?
a. 125
b. 250
c. 225
d. 150
Answer: Option(b)
-------------------------------------------
51. Which of the following devices takes data
sent from one network device and forwards
it to the destination node based on MAC
address ?
a. Hub
b. Modem
c. Switch
d. Gateway
Answer: Option(c)
-------------------------------------------
52. In Ethernet CSMA/CD, the special bit
sequence transmitted by media access
management to handle collision is called
a. Preamble
b. Postamble
c. Jam
d. None of the above
Answer: Option(c)
-------------------------------------------
53. Let C be a binary linear code with minimum
distance 2t + 1 then it can correct upto _____
bits of error.
a. t + 1
b. t
c. t - 2
d. t / 2
Answer: Option(b)
-------------------------------------------
54. In CRC if the data unit is 100111001 and the
divisor is 1011 then what is dividend at the
receiver?
a. 100111001101
b. 100111001011
c. 100111001
d. 100111001110
Answer: Option(b)
-------------------------------------------
55. A certain population of ALOHA users
manages to generate 70 request/sec. If the
time is slotted in units of 50 msec, then
channel load would be
a. 4.25
b. 3.5
c. 350
d. 450
Answer: Option(b)
-------------------------------------------
56. Match the following
a. (1)
b. (2)
c. (3)
d. (4)
Answer: Option(a)
-------------------------------------------
57. If the frame to be transmitted is 1101011011
and the CRC polynomial to be used for
generating checksum is x
4+ x + 1, then what
is the transmitted frame?
a. 11010110111011
b. 11010110111101
c. 11010110111110
d. 11010110111001
Answer: Option(c)
-------------------------------------------
58. What will be the efficiency of a Stop and
Wait protocol, if the transmission time for a
frame is 20ns and the propagation time is
30ns?
a. 20%
b. 25%
c. 40%
d. 66%
Answer: Option(b)
-------------------------------------------
59. Bit stuffing refers to
a. inserting a 0 in user stream
to differentiate it with a flag
b. inserting a 0 in flag stream to
avoid ambiguity
c. appending a nipple to the flag
sequence
d. appending a nipple to the use
data stream
Answer: Option(a)
-------------------------------------------
60. _______ can detect burst error of length less
than or equal to degree of the polynomial
and detects burst errors that affect odd
number of bits.
a. Hamming Code
b. CRC
c. VRC
d. None of the above
Answer: Option(b)
-------------------------------------------
Unit-III
-------------------------------------------
1. The network layer is concerned with
__________ of data.
a. bits
b. frames
c. packets
d. bytes
Answer: Option(c)
-------------------------------------------
2. Which one of the following is not a function
of network layer?
a. routing
b. inter-networking
c. congestion control
d. error control
Answer: Option(d)
-------------------------------------------
3. In virtual circuit network each packet
contains ___________
a. full source and destination address
b. a short VC number
c. only source address
d. only destination address
Answer: Option(b)
-------------------------------------------
4. Which of the following is not correct in
relation to multi-destination routing?
a. is same as broadcast routing
b. contains the list of all destinations
c. data is not sent by packets
d. there are multiple receivers
Answer: Option(c)
-------------------------------------------
5. A 4 byte IP address consists of __________
a. only network address
b. only host address
c. network address & host address
d. network address & MAC address
Answer: Option(c)
-------------------------------------------
6. Which of the following routing algorithms
can be used for network layer design?
a. shortest path algorithm
b. distance vector routing
c. link state routing
d. all of the mentioned
Answer: Option(b)
-------------------------------------------
7. A subset of a network that includes all the
routers but contains no loops is called
________
a. spanning tree
b. spider structure
c. spider tree
d. special tree
Answer: Option(a)
-------------------------------------------
8. Which one of the following algorithm is not
used for congestion control?
a. traffic aware routing
b. admission control
c. load shedding
d. routing information protocol
Answer: Option(d)
-------------------------------------------
9. ICMP is primarily used for __________
a. error and diagnostic functions
b. addressing
c. forwarding
d. routing
Answer: Option(a)
-------------------------------------------
10. The network layer contains which
hardware device?
a. Routers, Bridges
b. Bridges only
c. Bridges and switches
d. Routers, Bridges and Switches
Answer: Option(d)
-------------------------------------------
11. Network layer protocol exits in _________
a. Host
b. Switches
c. Packets
d. Bridges
Answer: Option(a)
-------------------------------------------
12. What are the common protocols associated
with the network layer?
a. Address Resolution Protocol
b. Reverse Address Resolution Protocol
c. Internet protocol
d. Neighbour Discovery Protocol
Answer: Option(c)
-------------------------------------------
13. The network layer responds to request
from which layer?
a. Transport layer
b. Data layer
c. Application layer
d. Session layer
Answer: Option(a)
-------------------------------------------
14. The network layer issues request to which
layer?
a. Transport layer
b. Data layer
c. Application layer
d. Session layer
Answer: Option(b)
-------------------------------------------
15. What are called routers?
a. The devices that operates at session layer
b. The devices that operates at data layer
c. The devices that operates at application layer
d. The devices that operates at network
Answer: Option(d)
-------------------------------------------
16. ICMP stands for __________
a. Internet Coordinate Message Protocol
b. Internet Control Message Protocol
c. Interconnect Control Message Protocol
d. Interconnect Coordinate Message Protocol
Answer: Option(b)
-------------------------------------------
17. Packets will be transferred in how many
types?
a. 5 types
b. 4 types
c. 2 types
d. 3 types
Answer: Option(d)
-------------------------------------------
18. RIP stands for ________
a. Reduced Information Protocol
b. Routing Internet Protocol
c. Routing Information Protocol
d. Reduced Internet Protocol
Answer: Option(c)
-------------------------------------------
19. DDP stands for _________
a. Datagram Delivery Protocol
b. Device Delivery Protocol
c. Datagram Device Protocol
d. Device Datagram Protocol
Answer: Option(a)
-------------------------------------------
20. Which level is the network layer in the OSI model?
a. Third level
b. Fourth level
c. Second level
d. Fifth layer
Answer: Option(a)
-------------------------------------------
21. Which of the following is correct IPv4
address?
a. 124.201.3.1.52
b. 01.200.128.123
c. 300.142.210.64
d. 128.64.0.0
Answer: Option(d)
-------------------------------------------
22. How many versions available of IP?
a. 6 version
b. 4 version
c. 2 version
d. 1 version
Answer: Option(c)
-------------------------------------------
23. The term IPv4 stands for?
a. Internet Protocol Version 4
b. Internet Programming Version 4
c. International Programming Version 4
d. None of these
Answer: Option(a)
-------------------------------------------
24. Which of the following IP address class is
Multicast?
a. Class A
b. Class B
c. Class C
d. Class D
Answer: Option(d)
-------------------------------------------
25. Which form of byte assigning strategy is
adopted in class B type of network
corresponding to IP addresses?
a. Network.Node.Node.Node
b. Network.Network.Node.Node
c. Network.Network.Network.Node
d. Network.Node.Node.Node
Answer: Option(b)
-------------------------------------------
26. On which factors do the size of block
depends in classless addressing?
a. Nature & size of an entity
b. Number of addresses
c. Availability of the address space
d. All of the above
Answer: Option(a)
-------------------------------------------
27. The ability of a single network to span
multiple physical networks is known as
______
a. Subnetting
b. Masking
c. Fragmenting
d. Hopping
Answer: Option(a)
-------------------------------------------
28. Which field/s of ICMPv6 packet header
has/have a provision of minimal integrity level
concerning to verification for ICMP
messages?
a. Type
b. Code
c. Checksum
d. All of the above
Answer: Option(c)
-------------------------------------------
29. Which among the below stated datagram
discard code fields in ICMP is/are generated if
a router fails to forward a packet due to
administrative filtering?
a. Source Route Failed
b. Communication Administratively
Prohibited
c. Host Precedence Violation
d. Precedence Cut-off in Effect
Answer: Option(b)
-------------------------------------------
30. What are the problems involved in an IP
Fragmentation Process?
A. Loss of any fragment results in
rejection of all datagrams
B. Management of buffer space is
essential to handle reassembly process
C. No necessity of initializing the timer
after the reception of initial fragment
D. Multiple attempts can be made to
recover ICMP error message due to
connection-oriented IP service
a. A & B
b. C & D
c. B& C
d. A & D
Answer: Option(a)
-------------------------------------------
31. In an IPv4 datagram, the M bit is 0, the
value of HLEN is 10, the value of total length
is 400 and the fragment offset value is 300.
The position of the datagram, the sequence
numbers of the first and the last bytes of the
payload, respectively are
a. Last fragment, 2400 and 2789
b. First fragment, 2400 and 2759
c. Last fragment, 2400 and 2759
d. Middle fragment, 300 and 689
Answer: Option(c)
-------------------------------------------
32. Consider a source computer(S) transmitting
a file of size 106 bits to a destination computer
(D)over a network of two routers (R1 and R2)
and three links(L1, L2, and L3). L1connects S
to R1; L2 connects R1 to R2; and L3 connects
R2 to D. Let each link be of length 100 km.
Assume signals travel over each link at a speed
of 108 meters per second. Assume that the link
bandwidth on each link is 1Mbps. Let the file
be broken down into 1000 packets each of size
1000 bits. Find the total sum of transmission
and propagation delays in transmitting the file
from S to D?
a. 1005 ms
b. 1010 ms
c. 3000 ms
d. 3003 ms
Answer: Option(a)
-------------------------------------------
33. One of the header fields in an IP datagram
is the Time to Live (TTL) field. Which of the
following statements best explains the need for
this field?
a. It can be used to prioritize packets
b. It can be used to reduce delays
c. It can be used to optimize throughput
d. It can be used to prevent packet
looping
Answer: Option(d)
-------------------------------------------
34. For which one of the following reasons
does Internet Protocol (IP) use the time-tolive (TTL) field in the IP datagram header?
a. Ensure packets reach destination
within that time
b. Discard packets that reach later than
that time
c. Prevent packets from looping
indefinitely
d. Limit the time for which a packet gets
queued in intermediate routers.
Answer: Option(c)
-------------------------------------------
35. Which of the following statements is
TRUE?
a. Both Ethernet frame and IP packet
include checksum fields
b. Ethernet frame includes a checksum
field and IP packet includes a CRC
field
c. Ethernet frame includes a CRC
field and IP packet includes a
checksum field
d. Both Ethernet frame and IP packet
include CRC fields
Answer: Option(c)
-------------------------------------------
36. Which of the following assertions is
FALSE about the Internet Protocol (IP)?
a. It is possible for a computer to have
multiple IP addresses
b. IP packets from the same source to the
same destination can take different
routes in the network
c. IP ensures that a packet is discarded if
it is unable to reach its destination
within a given number of hops
d. The packet source cannot set the
route of an outgoing packets; the
route is determined only by the
routing tables in the routers on the
way
Answer: Option(d)
-------------------------------------------
37. An organization is granted the block
130.34.12.64/26. It needs to have 4 subnets.
Which of the following is not an address of
this organization?
a. 130.34.12.124
b. 130.34.12.89
c. 130.34.12.70
d. 130.34.12.132
Answer: Option(d)
-------------------------------------------
38. An IP datagram of size 1000 bytes arrives
at a router. The router has to forward this
packet on a link whose MTU (maximum
transmission unit) is 100 bytes. Assume that
the size of the IP header is 20 bytes. The
number of fragments that the IP datagram will
be divided into for transmission is :
a. 10
b. 50
c. 12
d. 13
Answer: Option(d)
-------------------------------------------
39. In an IPv4 datagram, the M bit is 0, the
value of HLEN is 10, the value of total length
is 400 and the fragment offset value is 300.
The position of the datagram, the sequence
numbers of the first and the last bytes of the
payload, respectively are
a. Last fragment, 2400 and 2789
b. First fragment, 2400 and 2759
c. Last fragment, 2400 and 2759
d. Middle fragment, 300 and 689
Answer: Option(c)
-------------------------------------------
40. Dynamic routing protocol enable routers to
a. Dynamically discover and maintain
routes
b. Distribute routing updates to other
routers
c. Reach agreement with other routers
about the network topology
d. All of the above
Answer: Option(d)
-------------------------------------------
41. When a host on network A sends a message
to a host on network B, which address does
the router look at?
a. Port
b. IP
c. Physical
d. Subnet mask
Answer: Option(b)
-------------------------------------------
42. For n devices in a network, ________
number of duplex-mode links are required
for a mesh topology.
a. n(n + 1)
b. n (n – 1)
c. n(n + 1)/2
d. n(n – 1)/2
Answer: Option(d)
-------------------------------------------
43. __________ is a bit-oriented protocol for
communication over point-to-point and
multipoint links.
a. Stop-and-wait
b. HDLC
c. Sliding window
d. Go-back-N
Answer: Option(c)
-------------------------------------------
44. In Challenge-Response authentication the
claimant ________.
a. Proves that she knows the secret
without revealing it
b. Proves that she doesn’t know the
secret
c. Reveals the secret
d. Gives a challenge
Answer: Option(a)
-------------------------------------------
45. An organization is granted the block
130.34.12.64/26. It needs to have 4 subnets.
Which of the following is not an address of
this organization?
a. 130.34.12.124
b. 130.34.12.89
c. 130.34.12.70
d. 130.34.12.132
Answer: Option(d)
-------------------------------------------
46. A pure ALOHA Network transmits 200 bit
frames using a shared channel with 200
Kbps bandwidth. If the system (all stations
put together) produces 500 frames per
second, then the throughput of the system is
______.
a. 0.384
b. 0.184
c. 0.286
d. 0.58
Answer: Option(b)
-------------------------------------------
47. IPv6 does not support which of the
following addressing modes?
a. unicast addressing
b. multicast addressing
c. broadcast addressing
d. anycast addressing
Answer: Option(c)
-------------------------------------------
48. What is IP class and number of subnetworks if the subnet mask is 255.224.0.0?
a. Class A, 3
b. Class A, 8
c. Class B, 3
d. Class B, 32
Answer: Option(b)
-------------------------------------------
49. Which of the following is not a congestion
policy at network layer?
a. Flow Control Policy
b. Packet Discard Policy
c. Packet Lifetime Management Policy
d. Routing Algorithm
Answer: Option(a)
-------------------------------------------
50. A network with bandwidth of 10 Mbps can
pass only an average of 15,000 frames per
minute with each frame carrying an average
of 8,000 bits. What is the throughput of this
network?
a. 2 Mbps
b. 60 Mbps
c. 120 Mbps
d. 10 Mbps
Answer: Option(a)
-------------------------------------------
51. Dynamic routing protocol enable routers to
a. Dynamically discover and maintain
routes
b. Distribute routing updates to other
routers
c. Reach agreement with other routers
about the network topology
d. All of the above
Answer: Option(d)
-------------------------------------------
52. The address of a class B host is to be split
into subnets with a 6-bit subnet number.
What is the maximum number of subnets
and the maximum number of hosts in each
subnet?
a. 62 subnets and 262142 hosts.
b. 64 subnets and 262142 hosts.
c. 62 subnets and 1022 hosts.
d. 64 subnets and 1024 hosts
Answer: Option(c)
-------------------------------------------
53. A network with bandwidth of 10 Mbps can
pass only an average of 12,000 frames per
minute with each frame carrying an average
of 10,000 bits. What is the throughput of
this network ?
a. 1 Mbps
b. 2 Mbps
c. 10 Mbps
d. 12 Mbps
Answer: Option(b)
-------------------------------------------
54. Suppose transmission rate of a channel is
32 kbps. If there are ‘8’ routes from source
to destination and each packet p contains
8000 bits. Total end to end delay in sending
packet P is _____.
a. 2 sec
b. 3 sec
c. 4 sec
d. 1 sec
Answer: Option(a)
-------------------------------------------
55. Which of the following routing technique /
techniques is / are used in distributed
systems ?
A. Fixed Routing
B. Virtual Routing
C. Dynamic Routing
a. A Only
b. A and B only
c. C only
d. All A,B,C
Answer: Option(a)
-------------------------------------------
56. Consider the given network implementation
scenario. For the given classful NID
199.10.20.0/24, the requirement is to create
13 subnets. With given details, find the
range of first and last valid IP in 15th
subnet.
a. 199.10.20.208 to 199.10.20.222
b. 199.10.20.225 to 199.10.20.238
c. 199.10.20.193 to 199.10.20.206
d. Not of these
Answer: Option(b)
-------------------------------------------
57. __________ do not take their decisions on
measurements or estimates of the current
traffic and topology.
a. Static algorithms
b. Adaptive algorithms
c. Non - adaptive algorithms
d. Recursive algorithms
Answer: Option(c)
-------------------------------------------
58. A subnet has been assigned a subnet mask
of 255.255.255.192. What is the maximum
number of hosts that can belong to this
subnet?
a. 14
b. 30
c. 62
d. 126
Answer: Option(c)
-------------------------------------------
59. In the TCP/IP protocol suite, which one of
the following is NOT part of the IP header?
a. Fragment Offset
b. Source IP address
c. Destination IP address
d. Destination port number
Answer: Option(d)
-------------------------------------------
60. In the network 200.10.11.144/27, the fourth
octet (in decimal) of the last IP address of
the network which can be assigned to a host
is ________
a. 158
b. 255
c. 222
d. 223
Answer: Option(a)
-------------------------------------------
61. Which one of the following fields of an IP
header is NOT modified by a typical IP
router?
a. Checksum
b. Source address
c. Time to Live (TTL)
d. Length
Answer: Option(b)
-------------------------------------------
62. If a Company require 60 hosts then What is
the best possible subnet mask?
a. 255.255.255.0
b. 255.255.255.192
c. 255.255.225.224
d. 225.225.255.240
Answer: Option(b)
-------------------------------------------
63. The address resolution protocol (ARP) is
used for
a. Finding the IP address from the DNS
b. Finding the IP address of the default
gateway
c. Finding the IP address that
corresponds to a MAC address
d. Finding the MAC address that
corresponds to an IP address
Answer: Option(d)
-------------------------------------------
COMPUTER NETWORKS 2020-21
23 University Academy
Unit-IV
1. Transport layer aggregates data from
different applications into a single stream
before passing it to ____________
a. network layer
b. data link layer
c. application layer
d. physical layer
Answer: Option(a)
-------------------------------------------
2. Which of the following are transport layer
protocols used in networking?
a. TCP and FTP
b. UDP and HTTP
c. TCP and UDP
d. HTTP and FTP
Answer: Option(c)
-------------------------------------------
3. User datagram protocol is called
connectionless because _____________
a. all UDP packets are treated
independently by transport layer
b. it sends data as a stream of related
packets
c. it is received in the same order as sent
order
d. it sends data very quickly
Answer: Option(a)
-------------------------------------------
4. Transmission control protocol ___________
a. is a connection-oriented protocol
b. uses a three way handshake to
establish a connection
c. receives data from application as a
single stream
d. all of the mentioned
Answer: Option(d)
-------------------------------------------
5. Socket-style API for windows is called
____________
a. wsock
b. winsock
c. wins
d. sockwi
Answer: Option(d)
-------------------------------------------
6. An endpoint of an inter-process
communication flow across a computer
network is called
a. socket
b. pipe
c. port
d. machine
Answer: Option(a)
-------------------------------------------
7. Which one of the following is a version of
UDP with congestion control?
a. datagram congestion control
protocol
b. stream control transmission protocol
c. structured stream transport
d. user congestion control protocol
Answer: Option(a)
-------------------------------------------
8. A _____ is a TCP name for a transport
service access point.
a. port
b. pipe
c. node
d. protocol
Answer: Option(a)
-------------------------------------------
9. Transport layer protocols deals with _____
a. application to application
communication
b. process to process communication
c. node to node communication
d. man to man communication
Answer: Option(b)
-------------------------------------------
10. Which of the following is a transport layer
protocol?
a. stream control transmission
protocol
b. internet control message protocol
c. neighbor discovery protocol
d. dynamic host configuration protocol
Answer: Option(a)
-------------------------------------------
11. What are the functions of the transport
layer?
a. Multiplexing/ Demultiplexing
b. Connection less Services
c. Connection oriented service
d. Congestion control
Answer: Option(a)
-------------------------------------------
12. Which services are provided by transport
layer?
a. Error control
b. Connection service
c. Connection less service
d. Congestion control
Answer: Option(a)
-------------------------------------------
13. TCP and UDP are called ________
a. Application protocols
b. Session protocols
c. Transport protocols
d. Network protocols
Answer: Option(c)
-------------------------------------------
14. Security based connection is provided by
which layer?
a. Network layer
b. Session layer
c. Application layer
d. Transport layer
Answer: Option(d)
-------------------------------------------
15. TCP is the standard protocol with std no?
a. 5
b. 4
c. 7
d. 3
Answer: Option(c)
-------------------------------------------
16. Using which method in transport layer data
integrity can be ensured?
a. Checksum
b. Repetition codes
c. Cyclic redundancy checks
d. Error correcting codes
Answer: Option(a)
-------------------------------------------
17. Buffer overrun can be reduced by using
what?
a. Traffic control
b. Flow control
c. Byte orientation
d. Data integrity
Answer: Option(b)
-------------------------------------------
18. Transport layer can identify the symptoms
of overload nodes using _________
a. Flow control
b. Traffic control
c. Byte orientation
d. Data integrity
Answer: Option(b)
-------------------------------------------
19. Transport layer is which layer in OSI
model?
a. Fourth layer
b. Third layer
c. Second layer
d. Fifth layer\
Answer: Option(a)
-------------------------------------------
20. Congestion control can control traffic entry
into a telecommunications network, so to
avoid _________
a. Congestive connection
b. Connection collapse
c. Congestive collapse
d. Collapse congestive
Answer: Option(c)
-------------------------------------------
21. FCP stands for _________
a. Fiber Channel Protocol
b. Field Channel Protocol
c. Fast Channel Protocol
d. Fiber Carrying Protocol
Answer: Option(a)
-------------------------------------------
22. UDP packets are called as _________
a. Segments
b. Checksum
c. Frames
d. Datagrams
Answer: Option(d)
-------------------------------------------
23._________ does not provide reliable end to
end communication.
a. TCP
b. UDP
c. Both TCP and UDP
d. Neither TCP nor UDP
Answer: Option(b)
-------------------------------------------
24. ARQ stands for __________
a. Automatic Repeat Request
b. Automatic Request Repeat
c. Application Repeat Request
d. Application Request Repeat
Answer: Option(a)
-------------------------------------------
25. The transport layer protocols used for real
time multimedia, file transfer, DNS and email,
respectively are:
a. TCP, UDP, UDP and TCP
b. UDP, TCP, TCP and UDP
c. UDP, TCP, UDP and TCP
d. TCP, UDP, TCP and UDP
Answer: Option(c)
-------------------------------------------
26. Which of the following transport layer
protocols is used to support electronic mail?
a. SMTP
b. IP
c. TCP
d. UDP
Answer: Option(c)
-------------------------------------------
27. Consider an instance of TCP’s Additive
Increase Multiplicative Decrease (AIMD)
algorithm where the window size at the start of
the slow start phase is 2 MSS and the
threshold at the start of the first transmission is
8 MSS. Assume that a timeout occurs during
the fifth transmission. Find the congestion
window size at the end of the tenth
transmission.
a. 8 MSS
b. 14 MSS
c. 7 MSS
d. 12 MSS
Answer: Option(c)
-------------------------------------------
28. A layer-4 firewall (a device that can look
at all protocol headers up to the transport
layer) CANNOT
a. block entire HTTP traffic during
9:00PM and 5 :0OAM
b. block all ICMP traffic
c. stop incoming traffic from a specific
IP address but allow outgoing traffic
to the same IP address
d. block TCP traffic from a specific
user on a multi-user system during
9:00PM and 5:00AM
Answer: Option(d)
-------------------------------------------
29. Which of the following system calls results
in the sending of SYN packets?
a. socket
b. bind
c. listen
d. connect
Answer: Option(d)
-------------------------------------------
30. In the slow start phase of the TCP
congestion control algorithm, the size of the
congestion window
a. does not increase
b. increases linearly
c. increases quadratically
d. increases exponentially
Answer: Option(d)
-------------------------------------------
31. Which one of the following uses UDP as
the transport protocol?
a. HTTP
b. Telnet
c. DNS
d. SMTP
Answer: Option(c)
-------------------------------------------
32. the maximum window size for data
transmission using the selective reject
protocol with n-bit frame sequence
numbers is:
a. 2^n
b. 2^(n-1)
c. 2^n – 1
d. 2^(n-2)
Answer: Option(b)
-------------------------------------------
33. Which of the following is NOT true about
User Datagram Protocol in transport layer?
a. Works well in unidirectional
communication, suitable for broadcast
information.
b. It does three way handshake before
sending datagrams
c. It provides datagrams, suitable for
modeling other protocols such as in IP
tunneling or Remote Procedure Call
and the Network File System
d. The lack of retransmission delays
makes it suitable for real-time
applications
Answer: Option(b)
-------------------------------------------
34. Identify the correct order in which a server
process must invoke the function calls
accept, bind, listen, and recv according to
UNIX socket API
a. listen, accept, bind recv
b. bind, listen, accept, recv
c. bind, accept, listen, recv
d. accept, listen, bind, recv
Answer: Option(b)
-------------------------------------------
35. Consider the following statements.
I. TCP connections are full duplex.
II. TCP has no option for selective
acknowledgment
III. TCP connections are message
streams.
a. Only I is correct
b. Only I and II are correct
c. Only II and III are correct
d. All of I, II and III are correct
Answer: Option(a)
-------------------------------------------
36. Generally TCP is reliable and UDP is not
reliable. DNS which has to be reliable uses
UDP because
a. UDP is slower
b. DNS servers has to keep connections
c. DNS requests are generally very
small and fit well within UDP
segments
d. None of these
Answer: Option(c)
-------------------------------------------
37. Suppose there are n stations in a slotted
LAN. Each station attempts to transmit
with a probability P in each time slot. The
probability that only one station transmits
in a given slot is _______.
a. nP(1 – P)n – 1
b. nP
c. P(1 – P)n – 1
d. n
P
(1 – P)n – 1
Answer: Option(a)
-------------------------------------------
38. What is the maximum size of data that the
application layer can pass on to the TCP
layer below?
a. Any size
b. 216 bytes - size of TCP header
c. 216 bytes
d. 1500
Answer: Option(a)
-------------------------------------------
39. An ACK number of 1000 in TCP always
means that
a. 999 bytes have been successfully
received
b. 1000 bytes have been successfully
received
c. 1001 bytes have been successfully
received
d. None of the above
Answer: Option(d)
-------------------------------------------
40. Suppose you are browsing the world wide
web using a web browser and trying to
access the web servers. What is the
underlying protocol and port number that
are being used?
a. UDP, 80
b. TCP, 80
c. TCP, 25
d. UDP, 25
Answer: Option(b)
-------------------------------------------
41. If link transmits 4000 frames per second
and each slot has 8 bits, the transmission
rate of circuit of this TDM is ______.
a. 64 Kbps
b. 32 Mbps
c. 32 Kbps
d. 64 MbpS
Answer: Option(c)
-------------------------------------------
42. Which algorithm is used to shape the bursty
traffic into a fixed rate traffic by averaging
the data rate?
a. solid bucket algorithm
b. spanning tree algorithm
c. hocken helm algorithm
d. leaky bucket algorithm
Answer: Option(d)
-------------------------------------------
43. Four channels are multiplexed using TDM.
If each channel sends 100 bytes/second and
we multiplex 1 byte per channel, then the
bit rate for the link is __________.
a. 400 bps
b. 800 bps
c. 1600 bps
d. 3200 bps
Answer: Option(d)
-------------------------------------------
44. A device is sending out data at the rate of
2000 bps. How long does it take to send a
file of 1,00,000 characters ?
a. 50
b. 200
c. 400
d. 800
Answer: Option(c)
-------------------------------------------
45. The TCP sliding window
a. can be used to control the flow of
information
b. always occurs when the field value is
0
c. always occurs when the field value is
1
d. occurs horizontally
Answer: Option(a)
-------------------------------------------
46. The maximum payload of a TCP segment
is:
a. 65,535
b. 65,515
c. 65,495
d. 65,475
Answer: Option(c)
-------------------------------------------
47. Silly Window Syndrome is related to
a. Error during transmission
b. File transfer protocol
c. Degrade in TCP performance
d. Interface problem
Answer: Option(c)
-------------------------------------------
48. SSL is not responsible for
a. Mutual authentication of client &
server
b. Secret communication
c. Data Integrity protection
d. Error detection and correction
Answer: Option(d)
-------------------------------------------
49. Which of the following is not a field in
TCP header?
a. Sequence number
b. Fragment offset
c. Checksum
d. Window size
Answer: Option(b)
-------------------------------------------
50. To guarantee correction of upto t errors, the
minimum Hamming distance d min in a
block code must be ________.
a. t+1
b. t−2
c. 2t−1
d. 2t+1
Answer: Option(d)
-------------------------------------------
Unit-V
-------------------------------------------
1. The ____ layer is the network dialog
controller.
a. network
b. transport
c. session
d. presentation
Answer: Option(c)
-------------------------------------------
2. The ____ layer establishes, maintains, and
synchronizes the interaction between
communicating systems.
a. network
b. transport
c. session
d. presentation
Answer: Option(c)
-------------------------------------------
3. The session layer lies between the
______layer and the presentation layer.
a. network
b. transport
c. data link
d. application
Answer: Option(b)
-------------------------------------------
4. The _____ layer lies between the session
layer and he application layer.
a. network
b. transport
c. data link
d. presentation
Answer: Option(d)
-------------------------------------------
5. The _____ layer uses data compression to
reduce the number of bits to be transmitted.
a. presentation
b. network
c. data link
d. application
Answer: Option(a)
-------------------------------------------
6. The functionalities of the presentation layer
include ____________
a. Data compression
b. Data encryption
c. Data description
d. All of the mentioned
Answer: Option(d)
-------------------------------------------
7. Encryption and decryption are functions of
which layer?
a. transport
b. session
c. application
d. presentation
Answer: Option(d)
-------------------------------------------
8. Which of the following layers of the OSI
reference model is concerned with the syntax
of data exchanged between application
entities?
a. Presentation layer
b. Application layer
c. Transportation layer
d. Session layer
Answer: Option(a)
-------------------------------------------
9. In respect of OSI model, LANs implement
a. lower two layers
b. all seven layers
c. upper five layers
d. None of the above
Answer: Option(b)
-------------------------------------------
10. In OSI model, which of the following layer
transforms information from machine format
into that understandable by user
a. application
b. session
c. presentation
d. physical
Answer: Option(c)
-------------------------------------------
11. Which network component/s is/are
involved in the Presentation layer of an OSI
model?
a. Gateway
b. Multiplexer & Oscilloscope
c. Amplifier & Hub
d. All of the above
Answer: Option(a)
-------------------------------------------
12. Which OSI layer assumes responsibility
for managing network connections between
applications?
a. Network layer
b. Data link layer
c. Application layer
d. Session layer
Answer: Option(d)
-------------------------------------------
13. The _______ layer ensures interoperability
between communicating devices through
transformation of data into a mutually agreed
upon format.
a. network
b. presentation
c. transport
d. data link
Answer: Option(b)
-------------------------------------------
14. In OSI model, when data is sent from
device A to device B, the 5th layer to receive
data at B is _________
a. Application layer
b. Transport layer
c. Link layer
d. Session layer
Answer: Option(d)
-------------------------------------------
15. Delimiting and synchronization of data
exchange is provided by __________
a. Application layer
b. Session layer
c. Transport layer
d. Link layer
Answer: Option(b)
-------------------------------------------
16. Which of the following layers is an
addition to OSI model when compared with
TCP IP model?
a. Application layer
b. Presentation layer
c. Session layer
d. Session and Presentation layer
Answer: Option(d)
-------------------------------------------
17. In the OSI model, as a data packet moves
from the lower to the upper layers, headers are
a. Added
b. Removed
c. Rearranged
d. Randomized
Answer: Option(b)
-------------------------------------------
18. Which of the following statements can be
associated with OSI model?
a. A structured way to discuss and easier
update system components
b. One layer may duplicate lower layer
functionality
c. Functionality at one layer no way
requires information from another
layer
d. It is an application specific network
model
Answer: Option(b)
-------------------------------------------
19. In OSI model, session layer is responsible
for
a. Recovery
b. Check pointing
c. Both a and b
d. None of the above
Answer: Option(c)
-------------------------------------------
20. In which layer of OSI client send request
to the server?
a. Application layer
b. Presentation layer
c. Session layer
d. Transport layer
Answer: Option(c)
-------------------------------------------
21. What is the main function of Session layer
in OSI model?
a. Defines how data is formatted
between the devices
b. Made physical connection between
server and client
c. Both a and b
d. None of the above
Answer: Option(a)
-------------------------------------------
22. Sometimes, Session layer is also called
______ layer
a. Virtual layer
b. Port layer
c. Segmentation layer
d. Process layer
Answer: Option(b)
-------------------------------------------
23. In which layer of OSI session is first check
and then data is transmitted
a. Application layer
b. Presentation layer
c. Session layer
d. Transport layer
Answer: Option(c)
-------------------------------------------
24. Which of the following is the session layer
protocol or service?
a. SPDY
b. NetBIOS
c. PPTP
d. SAP
Answer: Option(c)
-------------------------------------------
25. TELNET, FTP, SMTP, Protocols fall in
the following layer of OSI reference
model?
a. Transport layer
b. Internet layer
c. Network layer
d. Application layer
Answer: Option(d)
-------------------------------------------
26. Which of the following is an application
layer service?
a. Remote log-in
b. File transfer and access
c. Mail service
d. All of the above
Answer: Option(d)
-------------------------------------------
27. Which DNS client maps an address to a
name or a name to an address especially
when required by a host?
a. Resolver
b. Mapper
c. Primary Server
d. Secondary Server
Answer: Option(a)
-------------------------------------------
28. Which application-level protocol plays a
crucial role in carrying out the data
definition and manipulation in addition to
X-500 features?
a. TCP
b. LDAP
c. FTP
d. None of the above
Answer: Option(b)
-------------------------------------------
29. Which intermediaries are more likely to
get involved during the transfer function
of an e-mail system?
a. Storage and forwarding of e-mail for
certain addresses
b. Act as gateways to other e-mail or
messaging systems
c. Both a & b
d. None of the above
Answer: Option(c)
-------------------------------------------
30. Which among the below specified
illustrations belongs to the category of
GUI based user agents?
a. mail
b. pine
c. Outlook & Netscape
d. All of the above
Answer: Option(c)
-------------------------------------------
31. Which phase/s of POP3 allow/s an user
agent to retrieve the messages as well as
to mark the messages for deletion
purpose?
a. Authorization Phase
b. Transaction Phase
c. Update Phase
d. All of the above
Answer: Option(b)
-------------------------------------------
32. Consider the assertions given below.
Which among them prove to be beneficial
for Persistent HTTP connections?
A. Reduction in latency over the subsequent requests
B. Pipeline-oriented connection over the
requests and responses
C. Increase in number of packets due to
TCP opens
D. Prevention in opening and closing of
some TCP connections
a. A & B
b. C & D
c. A & C
d. B & B
Answer: Option(a)
-------------------------------------------
33. Which URL method of HTTP performs
similar function as that of PUT method
only with an exception of request
comprising a list of differences that
exhibit the necessity to get implemented
in the existing file?
a. POST
b. GET
c. PATCH
d. OPTION
Answer: Option(c)
-------------------------------------------
34. Which language in WWW specifies a
web's way by describing threedimensional objects?
a. HTML
b. VRML
c. XML
d. UML
 Answer: Option(b)
-------------------------------------------
35. Which field of cookie in WWW
represents the server's directory structure
by identifying the utilization of part
associated with server's file tree?
a. Domain
b. Path
c. Content
d. Secure
Answer: Option(b)
-------------------------------------------
36. Which among the below mentioned
protocols provides a mechanism of
acquiring an IP address without manual
intervention in addition to plug and play
type of networking?
a. BOOTP
b. DHCP
c. Both a & b
d. None of the above
Answer: Option(b)
-------------------------------------------
37. Which of the following layers of the OSI
model is responsible for user interaction?
a.Layer 4
b.Layer 5
c.Layer 6
d.Layer 7
Answer: Option(d)
-------------------------------------------
38. What occurs in the session layer?
a.Data compression and encryption
b.MAC address are handled
c.binary to decimal conversion
d.sessions are created
Answer: Option(d)
-------------------------------------------
39. Which of the following is/are the
important applications of the application
layer?
a.Electronic mail
b.World Wide Web
c.USENET
d.All of the above
Answer: Option(d)
-------------------------------------------
40. The TCP/IP …………corresponds to the
combined session, presentation, and
application layers of the OSI model.
a.session layer
b.presentation layer
c.application layer
d.None of the above
 Answer: Option(c)
-------------------------------------------
41. The ……… protocol is based on end-toend delivery.
a. SMTP
b. TCP
c. IP
d. SCTP
Answer: Option(a)
-------------------------------------------
42. The well-known port of the SMTP server
is …….
a. 110
b. 25
c. 50
d. 20
Answer: Option(b)
-------------------------------------------
43. In the SMTP header field_____ is a
summary of the message being sent which
is specified by the sender.
a. Reply-to
b. Return-path
c. Subject
d. From
Answer: Option(c)
-------------------------------------------
44. In the SMTP herder field_____ is added
by the final transport system that delivers
the mail.
a. Reply-to
b. Return-path
c. Subject
d. From
Answer: Option(b)
-------------------------------------------
45. In SMTP mail transaction flow, the
sender SMTP establishes a TCP
connection with the destination SMTP
and then waits for the server to send a
……….
a. 220 service ready message
b. 421 service not available message
c. Both of the above
d. None of the above
Answer: Option(c)
-------------------------------------------
46. In the MIME header field____describes
how the object within the body is to be
interpreted.
a. content-type
b. content-transfer-encoding
c. content-description
d. content-id
Answer: Option(a)
-------------------------------------------
47. In the MIME header field, ____describes
how the object within the body was
encoded in order that it be included in the
message using a mail-safe form.
a. content-type
b. content-transfer-encoding
c. content-description
d. content-id
Answer: Option(b)
-------------------------------------------
48. In a/an ………… of DNS resolver, the
queried name server can return the best
answer it currently has back to the DNS
resolver.
a. Recursive queries
b. Iterative queries
c. Reverse queries
d. Inverse queries
Answer: Option(b)
-------------------------------------------
49. The TCP/IP _______ layer is equivalent
to the combined session, presentation, and
application layers of the OSI model.
a.data link
b.network
c.physical
d.application
Answer: Option(d)
-------------------------------------------
50. In TCP IP Model, when data is sent from
device A to device B, the 5th layer to
receive data at B is ____________
a.Application layer
b.Transport layer
c.Link layer
d.Session layer
Answer: Option(a)
-------------------------------------------
51. Which layer provides the services to user?
a.application layer
b.session layer
c.presentation layer
d.physical layer
Answer: Option(a)
-------------------------------------------
52. Application layer protocol defines ____
a.types of messages exchanged
b.message format, syntax and semantics
c.rules for when and how processes send
and respond to messages
d.all of the mentioned
Answer: Option(d)
-------------------------------------------
53. Which one of the following allows a user
at one site to establish a connection to
another site and then pass keystrokes
from local host to remote host?
a.HTTP
b.FTP
c.Telnet
d.TCP
Answer: Option(c)
-------------------------------------------
54. The ASCII encoding of binary data is
called
a. base 64 encoding
b. base 32 encoding
c. base 16 encoding
d. base 8 encoding
Answer: Option(a)
-------------------------------------------
55. Consider different activities related to
email:
m1: Send an email from a mail client to a mail
server
m2: Download an email from mailbox server
to a mail client
m3: Checking email in a web browser
Which is the application level protocol used in
each activity?
a. m1: HTTP m2: SMTP m3: POP
b. m1: SMTP m2: FTP m3: HTTP
c. m1: SMTP m2: POP m3: HTTP
d. m1: POP m2: SMTP m3: IMAP
Answer: Option(c)
-------------------------------------------
56. Identify the correct order in which the
following actions take place in an
interaction between a web browser and a
web server.
1. The web browser requests a
webpage using HTTP.
2. The web browser establishes a TCP
connection with the web server.
3. The web server sends the requested
webpage using HTTP.
4. The web browser resolves the
domain name using DNS.
a. 4,2,1,3
b. 1,2,3,4
c. 4,1,2,3
d. 2,4,1,3
Answer: Option(a)
-------------------------------------------
57. In one of the pairs of protocols given below, both the protocols can use multiple TCP connections between the same client and the server. Which one is that?
a. HTTP, FTP
b. HTTP, TELNET
c. FTP, SMTP
d. HTTP, SMTP
Answer: Option(a)
-------------------------------------------
58. Which one of the following statements is
NOT correct about HTTP cookies?
a. A cookies is a piece of code that has
the potential to compromise the
security of an Internet user
b. A cookie gains entry to the user’s
work area through an HTTP header
c. A cookie has an expiry date and time
d. Cookies can be used to track the
browsing pattern of a user at a
particular site
Answer: Option(a)
-------------------------------------------
59. Which of the following is/are example(s)
of stateful application layer protocols?
(i) HTTP
(ii) FTP
(iii) TCP
(iv) POP3
a. (i) and (ii) only
b. (ii) and (iii) only
c. (ii) and (iv) only
d. (iv) only
Answer: Option(c)
-------------------------------------------
60. Which of the following protocol is used
for transferring electronic mail messages
from one machine to another?
a. TELNET
b. FTP
c. SNMP
d. SMTP
Answer: Option(d)
-------------------------------------------
61. Which of the following protocols is used
by email server to maintain a central
repository that can be accessed from any
machine ?
a. POP3
b. IMAP
c. SMTP
d. DMSP
Answer: Option(b)
-------------------------------------------
62. A packet filtering firewall can
a. deny certain users from accessing a
service
b. block worms and viruses from
entering the network
c. disallow some files from being
accessed through FTP
d. block some hosts from accessing the
network
Answer: Option(d)
-------------------------------------------
63. Which of the following protocols is an
application layer protocol that establishes,
manages and terminates multimedia
sessions ?
a. Session Maintenance Protocol
b. Real - time Streaming Protocol
c. Real - time Transport Control Protocol
d. Session Initiation Protocol
Answer: Option(d)
-------------------------------------------
64. What is the size of the ‘total length’ field
in IPv4 datagram?
a. 4 bit
b. 8 bit
c. 16 bit
d. 32 bit
Answer: Option(c)
-------------------------------------------
65. What is one advantage of setting up a
DMZ(Demilitarized Zone) with two
firewalls?
a. You can control where traffic goes
in the three networks
b. You can do stateful packet filtering
c. You can do load balancing
d. Improve network performance
Answer: Option(a)

-------------------------------------------


-------------------------------------------
Practice Set-1
-------------------------------------------
1. The computer network is
A) Network computer with cable
B) Network computer without cable
C) Both of the above
D) None of the above
Answer: Option(C)
-------------------------------------------
2. FDDI used which type of physical
topology?
A) Bus
B) Ring
C) Star
D) Tree
Answer: Option(B)
-------------------------------------------
3. FTP stands for
A) File transfer protocol
B) File transmission protocol
C) Form transfer protocol
D) Form transmission protocol
Answer: Option(A)
-------------------------------------------
4. Ethernet system uses which of the
following technology.
A) Bus
B) Ring
C) Star
D) Tree
Answer: Option(A)
-------------------------------------------
5. Which of the following are the network
services?
A) File service
B) Print service
C) Database service
D) All of the above
Answer: Option(D)
-------------------------------------------
6. If all devices are connected to a central
hub, then topology is called
A) Bus Topology
B) Ring Topology
C) Star Topology
D) Tree Topology
Answer: Option(C)
-------------------------------------------
7. FDDI stands for
A) Fiber Distributed Data Interface
B) Fiber Data Distributed Interface
C) Fiber Dual Distributed Interface
D) Fiber Distributed Data Interface
Answer: Option(A)
-------------------------------------------
8. Which of the following is an application
layer service?
A) Network virtual terminal
B) File transfer, access and management
C) Mail service
D) All of the above
Answer: Option(C)
-------------------------------------------
9. Which is the main function of transport
layer?
A) Node to node delivery
B) End to end delivery
C) Synchronization
d) Updating and maintaining routing tables
Answer: Option(B)
-------------------------------------------
10. The..............layer change bits onto
electromagnetic signals.
A) Physical
B) Transport
C) Data Link
D) Presentation
Answer: Option(A)
-------------------------------------------
11. In mesh topology, relationship between
one device and another is ..............
A) Primary to peer
B) Peer to primary
C) Primary to secondary
D) Peer to Peer
Answer: Option(D)
-------------------------------------------
12. The performance of data communications
network depends on ..............
A) Number of users
B) The hardware and software
C) The transmission
D) All of the above
Answer: Option(D)
-------------------------------------------
13. Find out the OSI layer, which performs
token management.
A) Network Layer
B) Transport Layer
C) Session Layer
D) Presentation Layer
Answer: Option(C)
-------------------------------------------
14. The name of the protocol which provides
virtual terminal in TCP/IP model is.
A) Telnet
B) SMTP
C) HTTP
Answer: Option(A)
-------------------------------------------
15. The layer one of the OSI model is
A) Physical layer
B) Link layer
C) Router layer
D) Broadcast layer
Answer: Option(A)
-------------------------------------------
16. What is the name of the network
topology in which there are bidirectional links between eachpossible
node?
A) Ring
B) Star
C) Tree
D) Mesh
Answer: Option(D)
-------------------------------------------
17. What is the commonly used unit for
measuring the speed of data
transmission?
A) Bytes per second
B) Baud
C) Bits per second
D) Both B and C
Answer: Option(B)
-------------------------------------------
18. Which of the communication modes
support two way traffic but in only once
direction of a time?
A) Simplex
B) Half-duplex
C) Three - quarter's duplex
D) Full duplex
Answer: Option(B)
-------------------------------------------
19. The loss in signal power as light travels
down the fiber is called .............
A) Attenuation
B) Propagation
C) Scattering
D) Interruption
Answer: Option(A)
-------------------------------------------
20. Which of the following TCP/IP protocols
is used for transferring files form one
machine to another.
A) FTP
B) SNMP
C) SMTP
D) RPC
Answer: Option(A)
-------------------------------------------



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