BCA 4TH SEM COMPUTER NETWORK MCQ

1. Physical or logical arrangement of network is __________
a) Topology
b) Routing
c) Networking
d) Control
View Answer

Answer: a
Explanation: Topology in networks is the structure or pattern in which each and every node in the network is connected. There are many topologies in networking like bus, tree, ring, star, mesh, and hybrid topology. There is no particular best topology and a suitable topology can be chosen based on the kind of application of the network .

2. Which network topology requires a central controller or hub?
a) Star
b) Mesh
c) Ring
d) Bus
View Answer

Answer: a
Explanation: In star topology, no computer is connected to another computer directly but all the computers are connected to a central hub. Every message sent from a source computer goes through the hub and the hub then forwards the message only to the intended destination computer.

3. _______ topology requires a multipoint connection.
a) Star
b) Mesh
c) Ring
d) Bus
View Answer

Answer: d
Explanation: In bus topology, there is a single cable to which all the network nodes are connected. So whenever a node tries to send a message or data to other nodes, this data passes through all other nodes in the network through the cable. It is really simple to install but it’s not secure enough to be used in most of the computer network applications.

4. Data communication system spanning states, countries, or the whole world is ________
a) LAN
b) WAN
c) MAN
d) PAN
View Answer

Answer: b
Explanation: WAN is the abbreviation for Wide Area Network. This network extends over a large geographical area. WANs are used to connect cities, states or even countries. A wireless connection is required to build a WAN. The best example of WAN is the Internet.

5. Data communication system within a building or campus is________
a) LAN
b) WAN
c) MAN
d) PAN
View Answer

Answer: a
Explanation: LAN is an abbreviation for Local Area Network. This network interconnects computers in a small area such as schools, offices, residence etc. It is the most versatile kind of data communication system where most of the computer network concepts can be visibly used.

6. WAN stands for __________
a) World area network
b) Wide area network
c) Web area network
d) Web access network
View Answer

Answer: b
Explanation: WAN is the abbreviation for Wide Area Network. This network extends over a large geographical area. These are used to connect cities, states or even countries. They can be connected through leased lines or satellites.

7. In TDM, slots are further divided into __________
a) Seconds
b) Frames
c) Packets
d) Bits
View Answer

Answer: b
Explanation: TDM is the abbreviation for Time division multiplexing. It is technique for combining several low rate channels to a single high rate channel. For a certain time slot, the several channels could use the maximum bandwidth. Each channel is inactive for a period of time too. Some other multiplexing techniques are Frequency division multiplexing and Phase division multiplexing.

8. _____ is the multiplexing technique that shifts each signal to a different carrier frequency.
a) FDM
b) TDM
c) Both FDM & TDM
d) PDM
View Answer

Answer: a

1. The sharing of a medium and its link by two or more devices is called _________
a) Fully duplexing
b) Multiplexing
c) Micropleixng
d) Duplexing
View Answer

Answer: b
Explanation: Multiplexing is a method using which one can send multiples signals through a shared medium at the same time. This helps in using less resources and thus saving the cost of sending messages.

2. Multiplexing is used in _______
a) Packet switching
b) Circuit switching
c) Data switching
d) Packet & Circuit switching
View Answer

Answer: b
Explanation: Circuit switching is a switching method by which one can obtain a physical path between end points. Circuit switching method is also called a connection oriented network. Two nodes must be physically and logically connected to each other to create a circuit switching network.

3. Which multiplexing technique used to transmit digital signals?
a) FDM
b) TDM
c) WDM
d) FDM & WDM
View Answer

Answer: b
Explanation: TDM abbreviation for Time Division Multiplexing is a method used for digital signals. Whereas FDM and WDM abbreviation for Frequency Division Multiplexing, and Wavelength Division Multiplexing, are used for analog signals. TDM is used in applications like ISDN (Integrated Services Digital Network) and PSTN (Public Switched Telephone Network).

4. If there are n signal sources of same data rate, then the TDM link has _______ slots.
a) n
b) n/2
c) n*2
d) 2ⁿ
View Answer

Answer: a
Explanation: In TDM, the total unit of time is divided equally among all the signal sources and each and every source has access to the complete channel bandwidth during its allotted time slot. When the time slot of the source is not active, it remains idle and waits for its slot to begin.

5. If link transmits 4000frames per second, and each slot has 8 bits, the transmission rate of circuit this TDM is _________
a) 32kbps
b) 500bps
c) 500kbps
d) 32bps
View Answer

Answer: a
Explanation: Transmission rate= frame rate * number of bits in a slot.
Given: Frame rate = 4000/sec and number of bits in slot = 8
Thus, Transmission rate = (4000 * 8) bps
= 32000bps
= 32kbps

6. The state when dedicated signals are idle are called __________
a) Death period
b) Poison period
c) Silent period
d) Stop period
View Answer

Answer: c
Explanation: There are instances when connection between two endpoints has been established, but no communication or transfer of messages occurs. This period of time is called silent period. The silent period ends when either of the two endpoints starts the communication.

7. Multiplexing provides _________
a) Efficiency
b) Privacy
c) Anti jamming
d) Both Efficiency & Privacy
View Answer

Answer: d
Explanation: Multiplexing helps us to transfer our messages over a shared channel. This brings up the issue of privacy and efficiency. Fortunately, Multiplexing has high efficiency and high privacy when implemented because in the implementation, the transport layer of the OSI network model handles the function of multiplexing through interfaces called ports which provide the required efficiency and privacy.

8. In TDM, the transmission rate of a multiplexed path is always _______ the sum of the transmission rates of the signal sources.
a) Greater than
b) Lesser than
c) Equal to
d) Equal to or greater than
View Answer

Answer: a
Explanation: In TDM the transmission rate provided by the path that is multiplexed will always be greater than the sum of transmission rates of the single sources. This happens because the transmission rate is provided to each source only for a small period of time.

9. In TDM, slots are further divided into _________
a) Seconds
b) Frames
c) Packets
d) Bits
View Answer

1. Which topology has Multipoint connection:
a)Ring
b)Bus
c)Star
d)Mesh
e.both b and c
Answer b
2.Mesh topology, have devices which are connected via
a)single and multiple links
b)Multipoint link
c)Point to point link
d)No Link
e)None of the above
answer c
3.The topology which requires a central controller or hub is
a)Mesh
b)Star
c)Bus
d)Ring
e)both b and c
answer b
4.LAN has mostly used the topologies
a)Bus
b)ring
c)star
d)both of these
e)None of these
answer d
5.Which topologies have two or more Combination:
a) multigrid
b)Star Topology
c)Bus Topology
d)Ring topology
e)Hybrid
Answer e
6.In a mesh topology, each device has a dedicated topology of

a.Multipoint linking
b.Point to point linking
c.None of Above
d.Both a and b
e.Single and multiple links
answer a
7.Which topology has the highest reliability?
a.Mesh topology
b.Star topology
c.Ring Topology
d.Bus Topology
e.none of these
answer a
8.Star Topology is basically based on a central device __________ ?
a.HUB
b.Switch
c.gates
d.Both a and b
e.none of these
answer d
9. A topology that is responsible for describing the geometric arrangement of components that make up the LAN.
a) Complex
b) Physical
c) Logical
d) Incremental

Answer: b
10. LAN topology describes the possible connections between pairs of networked end-points that can communicate.
a) Complex
b) Physical
c) decrement
d) Incremental
e) Logical

Answer: e
11.In a network, participating computers are referred to as:
a) Clients
b) Servers
c) Nodes
d) CPUs
e) both a and c

Answer: c
12.Tokens are involved in a topology.
a) Star
b) hybrid
c) Bus
d) Daisy Chaining
e) Ring
Answer: e
13. A ______WAN can be developed by using any other transmission facility:
a) Multi-peer
b) peer-to-peer
c) Two-tiered
d) Three-tiered
e) Hybrids

Answer: b
14. The source computer sent the information along with?
a) data
b) module
c) token
d) element
e) both a and b

Answer: c
15. All the hubs of networks have a serially connected system of?
a) Bus
b) Ring
c) multi-peer
d) Star
e) Daisy chains
View Answer

Answer: e

1._______ field in the base header restricts the lifetime of a datagram In IPv6,
A) version
B) next-header
C) hop limit
D) neighbor-advertisement

Answer: C

2. An HLEN value of decimal 10 means _______In IPv4 header
A) 10 bytes of options
B) 40 bytes of options
C) 10 bytes in the header
D) 40 bytes in the header

Answer: D

3. In IPv4, an HLEN value of decimal 10 means _______.
A) 10 bytes of options
B) 40 bytes of options
C) 40 bytes in the header
D) none of the above

Answer: C

4._______ field in the base header and the sender IP address combine to indicate a unique path identifier In IPv6.
A) flow label
B) next header
C) hop limit
D) destination IP address

Answer: A

5. what is the value of the total length field in bytes In IPv4?
A) 428
B) 407
C) 107
D) 427

Answer: A

6.________ term means that IP provides no error checking.
A) reliable delivery
B) connection-oriented delivery
C) best-effort delivery
D) none of the above

Answer: C

7. ________ protocol is the transmission used by the TCP/IP suite.
A) ARP
B) IP
C) RARP
D) none of the above

Answer: B

8. what is the length of the data field given an HLEN value of 12 and the total length is 40,000 In IPv4?
A) 39,988
B) 40,012
C) 40,048
D) 39,952

Answer: D

9.what is needed to determine the number of the last byte of a fragment In IPv4?

A) Identification number
B) Offset number
C) Total length

D) (b) and (c)

Answer: D

10. _______size in the IPv4 header.

A) 20 to 60 bytes long
B) 20 bytes long
C) 60 bytes long
D) none of the above

Answer: A

11. In IPv6, the decision is based on the _______ field in the base header.
A) hop limit
B) priority
C) next header
D) none of the above

Answer: B

12.which bit value unambiguously identifies the datagram as a fragment In IPv4?
A) Do not bit? 0
B) More bit? 0
C) offset = 1000
D) none of the above

Answer: C

13. Which necessary part of the IPv6 datagram?
A) Base header
B) Extension header
C) Data packet from the upper layer
D) (a) and (c)

Answer: A

14. In IPv4, the total size of the datagram must be less than the _______.
A) MUT
B) MAT
C) MTU
D) none of the above

Answer: C

15.options are inserted between _________ and ___________ data,In IPv6, .
A) base header; extension header
B) base header; upper-layer data
C) base header; frame header
D) none of the above

Answer: B

16. datagram is fragmented into three smaller datagrams An IPv4. Which is true?
A) They do not fragment bit is set to 1 for all datagrams.
B) The more fragment bit is set to 0 for all datagrams.
C) The identification field is the same for all datagrams.
D) The offset field is the same

Answer: C

17. if the fragment offset has a value of 100, it means that _______ In IPv4,
A) datagram has not been fragmented
B) datagram is 100 bytes in size
C) the first byte of the datagram is byte 100
D) the first byte of the datagram is byte 800

Answer: D

18. IP is _________ datagram protocol.
A) an unreliable
B) a connectionless
C) both a and b
D) none of the above

Answer: C

19. IPv6 allows _________ security provisions than IPv4.
A) more
B) less
C) the same level
D) none of the above

Answer: A

20. The formerly IPv4 header field known as the service type field is now called?
A) IETF
B) checksum
C) differentiated services
D) none of the above

Answer: C

21. delivery service such as IPv4.
A) error checking
B) error correction
C) datagram acknowledgment
D) none of the above

Answer: D

22. The IPv4 header size _______.
A) 20 to 60 bytes long
B) 20 bytes long
C) 60 bytes long
D) none of the above

Answer: A

23. Which network layer from the sender to receiver deals with the necessity of a three-way handshake transmission of data?
A) Path determination
B) Forwarding
C) Call Set-up
D) All of the above

Answer: C

24.Transmission purpose is basically a combination of __________
A) group of bits
B) source & destination addresses
C) both a & b
D) none of the above

Answer: C

25.__________crucial role in functions of network layer?
A) Network Service Data Unit (NSDU)
B) Medium Access Control Unit (MACU)
C) Network Address Translation Unit (NATU)
D) None of the above

Answer: A

26._________form of byte assigning strategy is adopted in class B?

A) Network.Node.Node.Node
B) Network.Network.Node.Node
C) Network.Network.Network.Node
D) Network.Node.Node.Node

Answer: B

27. which size of the block depends on classless?

A) Nature & size of an entity
B) Number of addresses
C) Availability of the address space
D) All of the above

Answer: A

28. Which is the ability of a single network to span multiple physical networks?

A) Subnetting
B) Masking
C) Fragmenting
D) Hopping

Answer: A

29. Which field/s of ICMPv6 packet header has minimal integrity levels?

a. Type
b. Code
c. Checksum
d. All of the above

Answer:C

Choose the address of class D is
(A) Unicast
(B) Reserved
(C) Multicast
(D) None of the above

Answer(C) Multicast

Select the wrong class.
(A) CLASS A = 1 to 126
(B) CLASS C = 192 to 220
(C) CLASS B = 128 to 191
(D) CLASS D = 224 to 239

Answer (B) CLASS C = 192 to 220

Select the bits from where the class A address starts.
(A) 110
(B) 10

(D) 1111

Answer (C) 0
MCQ No – 23
Select the bits from where the class B address starts
(A) 0
(B) 110
(C) 10
(D) 1111

Answer (C) 10

Select the bits from where the class C address starts
(A) 0
(B) 10
(C) 110
(D) 1111

Answer (C) 110

Select which one of these is not a class of IP addresses.
(A) Class A
(B) Class F
(C) Class E
(D) Class B

Answer (B) Class F

Select the address of class A, B and C are
(A) Reserved
(B) Multicast
(C) Unicast
(D) None of the above

Answer (C) Unicast

Select the bits from where the class D address starts
(A) 0
(B) 10
(C) 110
(D) 1110

Answer (D) 1110

How many bits are in Version 6 of IP address?
(A) 64 bits
(B) 32 bits
(C) 128 bits
(D) 256 bits

Answer (C) 128 bits

Select the stands for IANA stands.
(A) Internal Associative Numbers Authority
(B) Internal Assigned Numbers Authority
(C) Internet Associative Numbers Authoritative
(D) Internet Assigned Numbers Authority
Answer (D) Internet Assigned Numbers Authority

RIR stands for ________
a) Regional Internal Registries
b) Registries Internet Regional
c) Regional Internet Registries
d) Registries Internal Regional
Answer Regional Internet Registries

Select from the following how many version /s of IP’s are there.
(A) 4 versions
(B) 3 versions
(C) 2 versions
(D) 1 version
Answer (C) 2 versions

Which one are the stands of VLSM?
(A) Version Length Subnet Masking
(B) Version Length Surface Masking
(C) Variable Length Surface Masking
(D) Variable Length Subnet Masking
Answer (D) Variable Length Subnet Masking

Which protocol include in desktops and operating systems.
(A) IPv3 protocol
(B) IPv4 protocol
(C) Both IPv6 and IPv4 protocol
(D) IPv6 protocol
Answer (D) IPv6 protocolIPv6 protocol

Select the field is specified by how the datagram should be handled?
(A) Type of Service
(B) Identification
(C) Header length
(D) Flags

(A) Type of Service
Select the number of bits has assigned to the identification field.
(A) 3
(B) 16
(C) 8
(D) 32

Answer (C) 8

Choose how many bits have assigned to the flag field.
(A) 2
(B) 8
(C) 3
(D) 16

Answer (B) 8

Select the flag value to identify the last fragment?
(A) 1
(B) 0
(C) 2
(D) 11

Answer (B) 0

Select the field that helps to check the rearrangement of the fragments?
(A) identifier
(B) flags
(C) offset
(D) protocols

Answer (C) offset

Select the field in IPv4 datagram is not about to fragmentation
(A) Flags
(B) TOS
(C) Offset
(D) Identifier

(B) TOS

Select the 1st bit In the flags field
(A) do not fragment a bit
(B) reserved for future use
(C) more fragment bit
(D) none of the above

Answer (B) reserved for future use

Select the field that is used to specify by how long an IP packet can reside in-network before it is finished?
(A) Identification
(B) Options
(C) TOS
(D) Time to live

Answer (D) Time to live

Select the field that is used for network testing, debugging, control routing, timing and management.
(A) Identification
(B) Options
(C) Flags
(D) Time to live

Answer (B) Options

classful addressing is replaced with In IPv4 address
(A) Classful advertising
(B) Classful addressing new version
(C) Classless addressing
(D) Classless advertising

Answer (C) Classless addressing
_____ bytes in dotted-decimal notation, in an IP address.
(A) 3
(B) 5
(C) 4
(D) none of the above

Answer (C) 4
Select the minimum header size of an IP packet.
(A) 16 bytes

(B) 20 bytes

(D) 10 bytes
Answer (B) 20 bytes

Select the size of Network bits and Host bits of Class A of IP address.
(A) Network bits 7, Host bits 23

(B) Network bits 8, Host bits 24

(D) Network bits 8, Host bits 23
Answer (C) Network bits 7, Host bits
Select the uses of subnetting.
(A) It speeds up the speed of the network

(B) It divides the network into network classes

(D) None of the above
Answer
(C) It divides one large network into several smaller ones
Select from the following which one is correct about Class B Address of IP address.
(A) Network bit – 18, Host bit – 16

(B) Network bit – 16, Host bit – 14

(D) Network bit – 12, Host bit – 14\

Answer (C) Network bit – 14, Host bit – 16

Select from the following which represents the last address of IP address.
(A) Unicast address

(B) Broadcast address

(D) None of the above

Answer (B) Broadcast address
Select the size of Host bits in Class B of IP address.
(A) 16

(B) 08

(D) 32
Answer (A) 16

Select from the following which one application is not for IP protocol

(A) is connectionless
(B) offer reliable service
(C) offer unreliable service
(D) no error checking
Answer (B) offer reliable service

Choose the header of the datagram in the IPv4 has.
(A) 0 to 20 bytes
(B) 20 to 60 bytes
(C) 20 to 40 bytes
(D) 20 to 80 bytes

Answer (B) 20 to 60 bytes

Select the format of the IP address.

(A) 34 bit

(B) 32 bit

(D) 64 bit
Answer (B) 32 bit
Choose the usable size of Network bits in Class B of IP address.
(A) 04

(B) 14

(D) 16
Answer (D) 16

Select the bits for the IP address.
(A) 24
(B) 128
(C) 64
(D) 32

Answer (D) 32

Select the size of the header If the value of HELEN in an IP packet is 0101.
(A) 20
(B) 5
(C) 40
(D) 60

Answer (A) 20

1. OSI stands for __________
a) open system interconnection
b) operating system interface
c) optical service implementation
d) open service Internet
View Answer

Answer: a
Explanation: OSI is the abbreviation for Open System Interconnection. OSI model provides a structured plan on how applications communicate over a network, which also helps us to have a structured plan for troubleshooting. It is recognized by the ISO as the generalized model for computer network i.e. it can be modified to design any kind of computer network.

2. The number of layers in ISO OSI reference model is __________
a) 4
b) 5
c) 6
d) 7
View Answer

Answer: d
Explanation: In OSI reference model, there are 7 layers namely Application, Presentation, Session, Transport, Network, Data Link and Physical layer. Each layer uses a protocol to perform its designated function, for example, the data link layer uses error detection protocols for error control functions.

3. TCP/IP model does not have ______ layer but OSI model have this layer.
a) session layer
b) transport layer
c) application layer
d) network layer
View Answer

Answer: a
Explanation: In OSI reference model, there are two layers which are not present in TCP/IP model. They are Presentation and Session layer. The functions of Presentation and Session layer in the OSI model are handled by the transport layer itself in TCP/IP.

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4. Which layer is used to link the network support layers and user support layers?
a) session layer
b) data link layer
c) transport layer
d) network layer
View Answer

Answer: c
Explanation: Physical, data link and network layers are network support layers and session, presentation and application layers are user support layers. The transport layer links these layers by segmenting and rearranging the data. It uses protocols like TCP and UDP.

5. Which address is used on the internet for employing the TCP/IP protocols?
a) physical address and logical address
b) port address
c) specific address
d) all of the mentioned
View Answer

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6. TCP/IP model was developed _____ the OSI model.
a) prior to
b) after
c) simultaneous to
d) with no link to
View Answer

Answer: a
Explanation: Several TCP/IP prototypes were developed at multiple research centers between 1978 and 1983, whereas OSI reference model was developed in the year 1984. TCP/IP was developed with the intention to create a model for the Internet while OSI was intended to be a general network model.

7. Which layer is responsible for process to process delivery in a general network model?
a) network layer
b) transport layer
c) session layer
d) data link layer
View Answer

Answer: b
Explanation: The role of Transport layer (Layer 4) is to establish a logical end to end connection between two systems in a network. The protocols used in Transport layer is TCP and UDP. The transport layer is responsible for segmentation of the data. It uses ports for the implementation of process-to-process delivery.

8. Which address is used to identify a process on a host by the transport layer?
a) physical address
b) logical address
c) port address
d) specific address
View Answer

Answer: c
Explanation: A port number is a way to identify a specific process to which an Internet or other network message is to be forwarded when it arrives at a server. Some examples of port numbers are port 20 which is used for FTP data, port 22 which is used for SSH remote login ,and port 23 which is used for TELNET.

9. Which layer provides the services to user?
a) application layer
b) session layer
c) presentation layer
d) physical layer
View Answer

Answer: a
Explanation: In networking, a user mainly interacts with application layer to create and send information to other computer or network. Application layer provides the interface between applications and the network. It is the top-most layer in both the TCP/IP and the OSI model.

10. Transmission data rate is decided by ____________
a) network layer
b) physical layer
c) data link layer
d) transport layer
View Answer

Answer: b

d) phase modulation
View Answer

Answer: a
Explanation: In analog modulation, digital low frequency baseband signal (digital bit stream) is transmitted over a higher frequency. Whereas in digital modulation the only difference is that the base band signal is of discrete amplitude level. The bits are represented by only two frequency levels, one for high and one for low.

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4. 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
View Answer

Answer: a
Explanation: The portion of physical layer that interfaces with the medium access control sublayer is Physical Signaling Sublayer. The main function of this layer is character encoding, reception, decoding and performs optional isolation functions. It handles which media connection the signal should be forwarded to physically.

5. 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
View Answer

Answer: d
Explanation: Anything dealing with a network cable or the standards in use – including pins, connectors and the electric current used is dealt in the physical layer (Layer 1). Physical layer deals with bit to bit delivery of the data aided by the various transmission mediums.

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6. 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
View Answer

Answer: c
Explanation: In asynchronous serial communication, the communication is not synchronized by clock signal. Instead of a start and stop signaling and flow control method is followed. Unlike asynchronous serial communication, in synchronous serial communication a clock signal is used for communication, so the start and stop method is not really required.

7. The physical layer is responsible for __________
a) line coding
b) channel coding
c) modulation
d) all of the mentioned
View Answer

Answer: d
Explanation: The physical layer is responsible for line coding, channel coding and modulation that is needed for the transmission of the information. The physical configuration including pins, connectors and the electric current used is dealt in the physical layer based on the requirement of the network application.

8. 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
View Answer

Answer: a
Explanation: Physical layer accepts data or information from the data link layer and converts it into hardware specific operations so as to transfer the message through physical cables. Some examples of the cables used are optical fiber cables, twisted pair cables and co-axial cables.

9. A single channel is shared by multiple signals by ____________
a) analog modulation
b) digital modulation
c) multiplexing
d) phase modulation
View Answer

Answer: c
Explanation: In communication and computer networks, the main goal is to share a scarce resource. This is done by multiplexing, where multiple analog or digital signals are combined into one signal over a shared medium. The multiple kinds of signals are designated by the transport layer which is the layer present on a higher level than the physical layer.

10. Wireless transmission of signals can be done via ___________
a) radio waves
b) microwaves
c) infrared
d) all of the mentioned
View Answer

Answer: d
Explanation: Wireless transmission is carried out by radio waves, microwaves and IR waves. These waves range from 3 Khz to above 300 Ghz and are more suitable for wireless transmission. Radio waves can penetrate through walls and are used in radio communications, microwaves and infrared (IR) waves cannot penetrate through walls and are used for satellite communications and device communications respectively.

1. The data link layer takes the packets from _________ and encapsulates them into frames for transmission.
a) network layer
b) physical layer
c) transport layer
d) application layer
View Answer

Answer: a
Explanation: In computer networks, the data from application layer is sent to transport layer and is converted to segments. These segments are then transferred to the network layer and these are called packets. These packets are then sent to data link layer where they are encapsulated into frames. These frames are then transferred to physical layer where the frames are converted to bits. Error control and flow control data is inserted in the frames at the data link layer.

2. Which of the following tasks is not done by data link layer?
a) framing
b) error control
c) flow control
d) channel coding
View Answer

Answer: d
Explanation: Channel coding is the function of physical layer. Data link layer mainly deals with framing, error control and flow control. Data link layer is the layer where the packets are encapsulated into frames.

3. 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
View Answer

Answer: b
Explanation: Media access control (MAC) deals with transmission of data packets to and from the network-interface card, and also to and from another remotely shared channel. The MAC sublayer also prevents collision using protocols like CSMA/CD.

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4. Header of a frame generally contains ______________
a) synchronization bytes
b) addresses
c) frame identifier
d) all of the mentioned
View Answer

Answer: d
Explanation: In a frame, the header is a part of the data that contains all the required information about the transmission of the file. It contains information like synchronization bytes, addresses, frame identifier etc. It also contains error control information for reducing the errors in the transmitted frames.

5. 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
View Answer

Answer: a
Explanation: The logical link control is a sublayer of data link layer whose main function is to manage traffic, flow and error control. The automatic repeat request error management mechanism is provided by the LLC when an error is found in the received frame at the receiver’s end to inform the sender to re-send the frame.

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6. 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
View Answer

Answer: b
Explanation: When a single bit error occurs in a data, it is called single bit error. When more than a single bit of data is corrupted or has error, it is called burst error. If a single bit error occurs, the bit can be simply repaired by inverting it, but in case of a burst error, the sender has to send the frame again.

7. CRC stands for __________
a) cyclic redundancy check
b) code repeat check
c) code redundancy check
d) cyclic repeat check
View Answer

Answer: a
Explanation: Cyclic redundancy check is a code that is added to a data which helps us to identify any error that occurred during the transmission of the data. CRC is only able to detect errors, not correct them. CRC is inserted in the frame trailer.

8. Which of the following is a data link protocol?
a) ethernet
b) point to point protocol
c) hdlc
d) all of the mentioned
View Answer

Answer: d
Explanation: There are many data link layer protocols. Some of them are SDLC (synchronous data link protocol), HDLC (High level data link control), SLIP (serial line interface protocol), PPP (Point to point protocol) etc. These protocols are used to provide the logical link control function of the Data Link Layer.

9. 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
View Answer

Answer: c
Explanation: In CSMA/CD, it deals with detection of collision after collision has occurred, whereas CSMA/CA deals with preventing collision. CSMA/CD is abbreviation for Carrier Sensing Multiple Access/Collision detection. CSMA/CA is abbreviation for Carrier Sensing Multiple Access/Collision Avoidance. These protocols are used for efficient multiple channel access.

10. 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
View Answer

Answer: a
Explanation: Piggybacking is a technique in which the acknowledgment is temporarily delayed so as to be hooked with the next outgoing data frame. It saves a lot of channel bandwidth as in non-piggybacking system, some bandwidth is reserved for acknowledgement.

1. The network layer is concerned with __________ of data.
a) bits
b) frames
c) packets
d) bytes
View Answer

Answer: c
Explanation: In computer networks, the data from the application layer is sent to the transport layer and is converted to segments. These segments are then transferred to the network layer and these are called packets. These packets are then sent to data link layer where they are encapsulated into frames. These frames are then transferred to physical layer where the frames are converted to bits.

2. Which one of the following is not a function of network layer?
a) routing
b) inter-networking
c) congestion control
d) error control
View Answer

Answer: d
Explanation: In the OSI model, network layer is the third layer and it provides data routing paths for network communications. Error control is a function of the data link layer and the transport layer.

3. 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
View Answer

Answer: c
Explanation: An ip address which is 32 bits long, that means it is of 4 bytes and is composed of a network and host portion and it depends on address class. The size of the host address and network address depends upon the class of the address in classful IP addressing.

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4. 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
View Answer

Answer: b
Explanation: A short VC number also called as VCID (virtual circuit identifier) is a type of identifier which is used to distinguish between several virtual circuits in a connection oriented circuit switched network. Each virtual circuit is used to transfer data over a larger packet switched network.

5. 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
View Answer

Answer: d
Explanation: The routing algorithm is what decides where a packet should go next. There are several routing techniques like shortest path algorithm, static and dynamic routing, decentralized routing, distance vector routing, link state routing, Hierarchical routing etc. The routing algorithms go hand in hand with the operations of all the routers in the networks. The routers are the main participants in these algorithms.

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6. 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
View Answer

Answer: c
Explanation: In multi-destination routing, there is more than one receiver and the route for each destination which is contained in a list of destinations is to be found by the routing algorithm. Multi-destination routing is also used in broadcasting.

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
View Answer

Answer: a
Explanation: Spanning tree protocol (STP) is a network protocol that creates a loop free logical topology for ethernet networks. It is a layer 2 protocol that runs on bridges and switches. The main purpose of STP is to ensure that you do not create loops when you have redundant paths in your network.

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
View Answer

Answer: d
Explanation: The Routing Information Protocol (RIP) is used by the network layer for the function of dynamic routing. Congestion control focuses on the flow of the traffic in the network and uses algorithms like traffic aware routing, admission control and load shedding to deal with congestion.

9. The network layer protocol for internet is __________
a) ethernet
b) internet protocol
c) hypertext transfer protocol
d) file transfer protocol
View Answer

Answer: b
Explanation: There are several protocols used in Network layer. Some of them are IP, ICMP, CLNP, ARP, IPX, HRSP etc. Hypertext transfer protocol is for application layer and ethernet protocol is for data link layer.

10. ICMP is primarily used for __________
a) error and diagnostic functions
b) addressing
c) forwarding
d) routing
View Answer

Answer: a
Explanation: ICMP abbreviation for Internet Control Message Protocol is used by networking devices to send error messages and operational information indicating a host or router cannot be reached. ICMP operates over the IP packet to provide error reporting functionality as IP by itself cannot report errors.

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
View Answer

Answer: a
Explanation: The flow of data in the OSI model flows in following manner Application -> Presentation -> Session -> Transport -> Network -> Data Link -> Physical. Each and every layer has its own set of functions and protocols to ensure efficient network performance.

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
View Answer

Answer: c
Explanation: Both TCP and UDP are transport layer protocol in networking. TCP is an abbreviation for Transmission Control Protocol and UDP is an abbreviation for User Datagram Protocol. TCP is connection oriented whereas UDP is connectionless.

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
View Answer

Answer: a
Explanation: UDP is an alternative for TCP and it is used for those purposes where speed matters most whereas loss of data is not a problem. UDP is connectionless whereas TCP is connection oriented.

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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
View Answer

Answer: d
Explanation: TCP provides reliable and ordered delivery of a stream of bytes between hosts communicating via an IP network. Major internet applications like www, email, file transfer etc rely on TCP. TCP is connection oriented and it is optimized for accurate delivery rather than timely delivery.

5. An endpoint of an inter-process communication flow across a computer network is called __________
a) socket
b) pipe
c) port
d) machine
View Answer

Answer: a
Explanation: Socket is one end point in a two way communication link in the network. TCP layer can identify the application that data is destined to be sent by using the port number that is bound to socket.

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6. Socket-style API for windows is called ____________
a) wsock
b) winsock
c) wins
d) sockwi
View Answer

Answer: b
Explanation: Winsock is a programming interface which deals with input output requests for internet applications in windows OS. It defines how windows network software should access network services.

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
View Answer

Answer: a
Explanation: The datagram congestion control is a transport layer protocol which deals with reliable connection setup, teardown, congestion control, explicit congestion notification, and feature negotiation. It is used in modern day systems where there are really high chances of congestion. The protocol was last updated in the year 2008.

8. A _____ is a TCP name for a transport service access point.
a) port
b) pipe
c) node
d) protocol
View Answer

Answer: a
Explanation: Just as the IP address identifies the computer, the network port identifies the application or service running on the computer. A port number is 16 bits. The combination of IP address preceded with the port number is called the socket address.

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
View Answer

Answer: b
Explanation: Transport layer is 4th layer in TCP/IP model and OSI reference model. It deals with logical communication between process. It is responsible for delivering a message between network host.

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
View Answer

Answer: a
Explanation: The Stream Control Transmission Protocol (SCTP) is a transport layer protocol used in networking system where streams of data are to be continuously transmitted between two connected network nodes. Some of the other transport layer protocols are RDP, RUDP, TCP, DCCP, UDP etc.

1. Physical or logical arrangement of network is __________
a) Topology
b) Routing
c) Networking
d) Control
View Answer

2. Which network topology requires a central controller or hub?
a) Star
b) Mesh
c) Ring
d) Bus
View Answer

3. _______ topology requires a multipoint connection.
a) Star
b) Mesh
c) Ring
d) Bus
View Answer

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4. Data communication system spanning states, countries, or the whole world is ________
a) LAN
b) WAN
c) MAN
d) PAN
View Answer

5. Data communication system within a building or campus is________
a) LAN
b) WAN
c) MAN
d) PAN
View Answer

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6. WAN stands for __________
a) World area network
b) Wide area network
c) Web area network
d) Web access network
View Answer

7. In TDM, slots are further divided into __________
a) Seconds
b) Frames
c) Packets
d) Bits
View Answer

8. _____ is the multiplexing technique that shifts each signal to a different carrier frequency.
a) FDM
b) TDM
c) Both FDM & TDM
d) PDM
View Answer

Answer: a
Explanation: FDM is an abbreviation for Frequency Division Multiplexing. This technique is used when the bandwidth of the channel is greater than the combined bandwidth of all the signals which are to be transmitted. The channel is active at all times unless a collision occurs with another channel trying to use the same frequency. Some other multiplexing techniques are Time division multiplexing and Phase division multiplexing.

1. The sharing of a medium and its link by two or more devices is called _________
a) Fully duplexing
b) Multiplexing
c) Micropleixng
d) Duplexing
View Answer

2. Multiplexing is used in _______
a) Packet switching
b) Circuit switching
c) Data switching
d) Packet & Circuit switching
View Answer

3. Which multiplexing technique used to transmit digital signals?
a) FDM
b) TDM
c) WDM
d) FDM & WDM
View Answer

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4. If there are n signal sources of same data rate, then the TDM link has _______ slots.
a) n
b) n/2
c) n*2
d) 2ⁿ
View Answer

5. If link transmits 4000frames per second, and each slot has 8 bits, the transmission rate of circuit this TDM is _________
a) 32kbps
b) 500bps
c) 500kbps
d) 32bps
View Answer

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6. The state when dedicated signals are idle are called __________
a) Death period
b) Poison period
c) Silent period
d) Stop period
View Answer

7. Multiplexing provides _________
a) Efficiency
b) Privacy
c) Anti jamming
d) Both Efficiency & Privacy
View Answer

9. In TDM, slots are further divided into _________
a) Seconds
b) Frames
c) Packets
d) Bits
View Answer

1. _____________ allows LAN users to share computer programs and data.
a) Communication server
b) Print server
c) File server
d) Network
View Answer

Answer: c
Explanation: A file server allows LAN users to share computer programs and data. It uses the File Transfer Protocol to provide this feature on ports 20 and 21. The file server works as a medium for the transfer.

2. With respect to physical media, STP cables stands for _________
a) Shielded Twisted Pair Cable
b) Spanning Tree Protocol Cable
c) Static Transport Protocol Cable
d) Shielded Two Power Cable
View Answer

Answer: a
Explanation: For physical media, STP cable stands for Shielded twisted pair cable. 100 Mbps is the max data capacity of STP cable and its default connector is RJ45. It is popularly used in LANs due to its ease of maintenance and installation.

3. A standalone program that has been modified to work on a LAN by including concurrency controls such as file and record locking is an example of ___________
a) LAN intrinsic software
b) LAN aware software
c) Groupware
d) LAN ignorant software
View Answer

Answer: a
Explanation: A standalone program that has been modified to work on a LAN by including concurrency controls such as file and record locking is an example of LAN intrinsic software. They are used to give better functionality of the program and the applications working over it to the users of the LAN.

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4. The __________ portion of LAN management software restricts access, records user activities and audit data, etc.
a) Configuration management
b) Security management
c) Performance management
d) Recovery management
View Answer

Answer: b
Explanation: The Security management portion of LAN management software restricts access, records user activities, and audit data. It is responsible for controlling access to the network based on predefined policy. The security management ensures authentication, confidentiality, and integrity in the LAN.

5. What is the max length of the Shielded twisted pair cable?
a) 100 ft
b) 200 ft
c) 100 m
d) 200 m
View Answer

Answer: c
Explanation: The max the Shielded twisted pair cable is 100 meters. If the length exceeds 100 meters, the loss of signals flowing through the cable would be really high. Thus, STP cable is more suitable for smaller networks like LANs.

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6. What is the max data transfer rate of STP cables?
a) 10 Mbps
b) 100 Mbps
c) 1000 Mbps
d) 10000 Mbps
View Answer

Answer: b
Explanation: 100 Mbps is the max data transfer rate that can be handled by STP cables, and its default connector is RJ-45. 100 Mbps is a feasible data transfer rate for small networks like LANs.

7. Which connector does the STP cable use?
a) BNC
b) RJ-11
c) RJ-45
d) RJ-69
View Answer

Answer: c
Explanation: RJ-45 is used for STP cable. 100 Mbps is the max data transfer rate that can be handled by STP. RJ-45 is popularly used to connect to modern-day routers, computer network cards, and other network devices.

8. What is the central device in star topology?
a) STP server
b) Hub/switch
c) PDC
d) Router
View Answer

Answer: b
Explanation: In star topology, no computer is connected to another computer directly but all the computers are connected to a central switch or hub. Every message sent from a source computer goes through the switch or hub and the switch or hub then forwards the message only to the intended destination computer.

9. What is the max data transfer rate for optical fiber cable?
a) 10 Mbps
b) 100 Mbps
c) 1000 Mbps
d) 10000 Mbps
View Answer

Answer: d
Explanation: Fiber channel speeds have been increasing over the years. 10000 Mbps is the max data transfer rate for optical fiber cables. It is said to be the fastest among the other kinds of cables like STP cables and co-axial cables. People are now using optical fiber cables instead of STP cables for LANs due to their fast data transfer capability.

10. Which of the following architecture uses the CSMA/CD access method?
a) ARC net
b) Ethernet
c) Router
d) STP server
View Answer

Answer: b
Explanation: Collision detection is not possible in Ethernet without extensions. Collision detection techniques for multiple access like CSMA/CD are used to detect collisions in the Ethernet architecture.

1. Which of this is not a guided media?
a) Fiber optical cable
b) Coaxial cable
c) Wireless LAN
d) Copper wire
View Answer

Answer: c
Explanation: Wireless LAN is unguided media.

2. UTP is commonly used in __________
a) DSL
b) FTTP
c) HTTP
d) None of the mentioned
View Answer

Answer: a
Explanation: Unshielded twisted pair(UTP) is commonly used in home access.

3. Coaxial cable consists of _______ concentric copper conductors.
a) 1
b) 2
c) 3
d) 4
View Answer

Answer: b
Explanation: Coaxial cable has an inner conductor surrounded by a insulating layer, which is surrounded by a conducting shield. Coaxial cable is used to carry high frequency signals with low losses.

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4. Fiber optics posses following properties __________
a) Immune electromagnetic interference
b) Very less signal attenuation
c) Very hard to tap
d) All of the mentioned
View Answer

Answer: d
Explanation: In fibre optics the transmission of information is in the form of light or photons. Due to all above properties mentioned in options fibre optics can be submerged in water and are used at more risk environments.

5. If an Optical Carrier is represented as OC-n, generally the link speed equals(in Mbps) __________
a) n*39.8
b) n*51.8
c) 2n*51.8
d) None of the mentioned
View Answer

Answer: b
Explanation: The base unit of transmission rates in optical fibre is 51.8 Mbits/s. So an optical carrier represented as OC-n has n*51.8 Mbits/s transmission speed. For eg. OC-3 has 3*51.8 Mbits/s speed.

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6. Terrestrial radio channels are broadly classifed into _____ groups.
a) 2
b) 3
c) 4
d) 1
View Answer

Answer: b
Explanation: The three types are those that operate over very short distance, those that operate in local areas, those that operate in the wide area.

7. Radio channels are attractive medium because __________
a) Can penetrate walls
b) Connectivity can be given to mobile user
c) Can carry signals for long distance
d) All of the mentioned
View Answer

Answer: d
Explanation: Radio channels can penetrate walls, can be used to provide connectivity to mobile users and can also carry signals for long distances.

8. Geostationary satellites ___________
a) Are placed at a fixed point above the earth
b) Rotate the earth about a fixed axis
c) Rotate the earth about a varying axis
d) All of the mentioned
View Answer

Answer: a
Explanation: They are placed in orbit at 36,000km above Earth’s surface.

1. A local telephone network is an example of a _______ network.
a) Packet switched
b) Circuit switched
c) Bit switched
d) Line switched
View Answer

Answer: b
Explanation: Circuit switching is connection oriented switching technique, whereas in the case of packet switching, it is connectionless. Circuit switching is implemented in the Physical layer, whereas packet switching is implemented in the Network layer. Internet too is based on the concept of circuit switching.

2. Most packet switches use this principle ____________
a) Stop and wait
b) Store and forward
c) Store and wait
d) Stop and forward
View Answer

Answer: b
Explanation: The packet switch will not transmit the first bit to outbound link until it receives the entire packet. If the entire packet is not received and the time-out period expires, the packet switch will inform the sender to resend the part of packet or the entire packet based on the algorithm being used.

3. If there are N routers from source to destination, the total end to end delay in sending packet P(L-> number of bits in the packet R-> transmission rate) is equal to ______________
a) N
b) (N*L)/R
c) (2N*L)/R
d) L/R
View Answer

Answer: b
Explanation: The equation to find the end to end delay when no. of bits, transmission rate and no. of routers is given by (N*L)/R. The total end to end delay, that is, nodal delay is the sum of all, the processing delay, queuing delay, transmission delay and propagation delay.

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4. What are the Methods to move data through a network of links and switches?
a) Packet switching and Line switching
b) Circuit switching and Line switching
c) Line switching and bit switching
d) Packet switching and Circuit switching
View Answer

Answer: d
Explanation: Packet switching and Circuit switching are two different types of switching methods used to connect the multiple communicating devices with one another. Packet switching is used in conventional LAN systems and circuit switching is used in telephonic systems.

5. The required resources for communication between end systems are reserved for the duration of the session between end systems in ________ method.
a) Packet switching
b) Circuit switching
c) Line switching
d) Frequency switching
View Answer

Answer: b
Explanation: In circuit switching, a physical path between the sender and receiver is established. This path is maintained until the connection is needed. Circuit switching is implemented in the Physical layer and is used in telephonic systems.

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6. As the resources are reserved between two communicating end systems in circuit switching, ___________ is achieved.
a) authentication
b) guaranteed constant rate
c) reliability
d) store and forward
View Answer

Answer: b
Explanation: Circuit switching is connection oriented and is always implemented in the physical layer. Once a path is set, all transmission occurs through the same path. It is used since the early times in telephonic systems.

7. In _________ systems, resources are allocated on demand.
a) packet switching
b) circuit switching
c) line switching
d) frequency switching
View Answer

Answer: a
Explanation: In packet switching, the bits are received in out of order and need to be assembled at the receiver end, whereas in the case of Circuit switching, all the bits are received in order. All transmissions may not occur through the same path in case of packet switching.

8. Which of the following is not an application layer service?
a) Network virtual terminal
b) File transfer, access, and management
c) Mail service
d) Error control
View Answer

Answer: d
Explanation: Application layer is the topmost layer in the OSI model. Network virtual terminal, mail service, file transfer, access and management are all services of the application layer. It uses protocols like HTTP, FTP, and DNS etc. to provide these services.

1. Which is not a application layer protocol?
a) HTTP
b) SMTP
c) FTP
d) TCP
View Answer

Answer: d
Explanation: TCP is transport layer protocol.

2. The packet of information at the application layer is called __________
a) Packet
b) Message
c) Segment
d) Frame
View Answer

Answer: b
Explanation: For Application, Presentation and Session layers there is no data format for message. Message is message as such in these three layers. But when it comes to Transport, Network, Data and Physical layer they have data in format of segments, packets, frames and bits respectively.

3. Which one of the following is an architecture paradigms?
a) Peer to peer
b) Client-server
c) HTTP
d) Both Peer-to-Peer & Client-Server
View Answer

Answer: d
Explanation: HTTP is a protocol

4. Application developer has permission to decide the following on transport layer side
a) Transport layer protocol
b) Maximum buffer size
c) Both Transport layer protocol and Maximum buffer size
d) None of the mentioned
View Answer

Answer: c
Explanation: Application layer provides the interface between applications and the network. So application developer can decide what transport layer to use and what should be its maximum buffer size.

5. Application layer offers _______ service.
a) End to end
b) Process to process
c) Both End to end and Process to process
d) None of the mentioned
View Answer

Answer: a
Explanation: End to End service is provided in the application layer. Whereas process to process service is provided at the transport layer.

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6. E-mail is _________
a) Loss-tolerant application
b) Bandwidth-sensitive application
c) Elastic application
d) None of the mentioned
View Answer

Answer: c
Explanation: Because it can work with available throughput.

7. Pick the odd one out.
a) File transfer
b) File download
c) E-mail
d) Interactive games
View Answer

Answer: d
Explanation: File transfer, File download and Email are services provided by the application layer and there are message and data oriented.

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 mentioned
View Answer

Answer: d
Explanation: The services provided by the application layer are network virtual terminal, file transfer, access and management, mail services, directory services, various file and data operations.

9. To deliver a message to the correct application program running on a host, the _______ address must be consulted.
a) IP
b) MAC
c) Port
d) None of the mentioned
View Answer

Answer: c
Explanation: IP address lets you know where the network is located. Whereas MAC address is a unique address for every device. Port address identifies a process or service you want to carry on.

10. Which is a time-sensitive service?
a) File transfer
b) File download
c) E-mail
d) Internet telephony
View Answer

Answer: d
Explanation: Internet telephony is Loss-tolerant other applications are not.

11. Transport services available to applications in one or another form _________
a) Reliable data transfer
b) Timing
c) Security
d) All of the mentioned
View Answer

Answer: d
Explanation: The transport services that are provided to application are reliable data transfer, security and timing. These are very important for proper end to end services.

12. Electronic mail uses which Application layer protocol?
a) SMTP
b) HTTP
c) FTP
d) SIP
View Answer

Answer: a
Explanation: Email uses various protocols like SMTP, IMAP and POP. The most prominent one used in application layer is SMTP.

statement regarding FTP.
a) FTP stands for File Transfer Protocol
b) FTP uses two parallel TCP connections
c) FTP sends its control information in-band
d) FTP sends exactly one file over the data connection
View Answer

Answer: c
Explanation: FTP is out-of-band because the data connection is done separately through port 20 and control connection is done separately through port 21.

5. If 5 files are transferred from server A to client B in the same session. The number of TCP connections between A and B is _______
a) 5
b) 10
c) 2
d) 6
View Answer

Answer: d
Explanation: The client would first initiate the TCP control connection through port 21. Then for every file transfer, a separate connection would be made through port 20. Now, since we have five files to be transferred, 1 control connection + 5 data connections = 6 total TCP connections.

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6. FTP server _____________
a) Maintains state information
b) Is stateless
c) Has single TCP connection for a file transfer
d) Has UDP connection for file transfer
View Answer

Answer: a
Explanation: FTP server maintains state information of every control connection to keep track of the active and inactive connections in the session. This helps the server decide which connection to terminate, in case the connection is inactive for too long.

7. The commands, from client to server, and replies, from server to client, are sent across the control connection in ________ bit ASCII format.
a) 8
b) 7
c) 3
d) 5
View Answer

Answer: b
Explanation: FTP was designed to transmit commands only in English characters that are possible with just 7 bits in ASCII. Even the media has to be converted to ASCII before transmission.

8. Find the FTP reply whose message is wrongly matched.
a) 331 – Username OK, password required
b) 425 – Can’t open data connection
c) 452 – Error writing file
d) 452 – Can’t open data connection
View Answer

Answer: d
Explanation: The correct response code for the message “Can’t open data connection” is 425. Response code 452 is sent usually when the connection is suddenly closed.

9. The data transfer mode of FTP, in which all the fragmenting has to be done by TCP is ________
a) Stream mode
b) Block mode
c) Compressed mode
d) Message mode
View Answer

Answer: a
Explanation: Stream mode is the default mode of FTP, in which the TCP transforms/fragments the data into segments, and then after the transmission is completed, converts it back to stream of bytes.

10. The password is sent to the server using ________ command.
a) PASSWD
b) PASS
c) PASSWORD
d) PWORD
View Answer

Answer: b
Explanation: The PASS command, preceded by the username, completes the user’s identification for access control in an FTP session. Without the valid password, the user won’t be able to initiate the FTP connection.

1. The entire hostname has a maximum of ___________
a) 255 characters
b) 127 characters
c) 63 characters
d) 31 characters
View Answer

Answer: a
Explanation: An entire hostname can have a maximum of 255 characters. Although each label must be from 1 to 63 characters long. Host name is actually a label that is given to a device in a network.

2. A DNS client is called _________
a) DNS updater
b) DNS resolver
c) DNS handler
d) none of the mentioned
View Answer

Answer: b
Explanation: DNS client also known as DNS resolver also known as DNS lookup helps to resolve DNS requests using an external DNS server.

3. Servers handle requests for other domains _______
a) directly
b) by contacting remote DNS server
c) it is not possible
d) none of the mentioned
View Answer

Answer: b
Explanation: Whenever a request is received at server from other domains, it handles this situation by contacting remote DNS server.

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4. DNS database contains _______
a) name server records
b) hostname-to-address records
c) hostname aliases
d) all of the mentioned
View Answer

Answer: d
Explanation: Domain Name system not only deals with mapping IP addresses with the hostname but also deals with exchange of information in the server.

5. If a server has no clue about where to find the address for a hostname then _______
a) server asks to the root server
b) server asks to its adjcent server
c) request is not processed
d) none of the mentioned
View Answer

Answer: a
Explanation: Root name servers are actually very important and critical as they are the first step in translating human readable hostnames into IP addresses for carrying out communication.

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6. Which one of the following allows client to update their DNS entry as their IP address change?
a) dynamic DNS
b) mail transfer agent
c) authoritative name server
d) none of the mentioned
View Answer

Answer: a
Explanation: Dynamic DNS or in short DDNS or DynDNS helps in automatically updating a name server in the DNS. This does not require manual editing.

7. Wildcard domain names start with label _______
a) @
b) *
c) &
d) #
View Answer

Answer: b
Explanation: A wildcard DNS record matches requests to a non existent domain name. This wildcard DNS record is specified by using asterisk “*” as the starting of a domain name.

8. The right to use a domain name is delegated by domain name registers which are accredited by _______
a) internet architecture board
b) internet society
c) internet research task force
d) internet corporation for assigned names and numbers
View Answer

Answer: d
Explanation: The ICANN (Internet Corporation for Assigned Names and Numbers) deals with IP address space allocation, protocol identifier assignment, generic and country code Top Level domain name system management (gTLD and ccTLD).

9. The domain name system is maintained by _______
a) distributed database system
b) a single server
c) a single computer
d) none of the mentioned
View Answer

Answer: a
Explanation: A domain name system is maintained by a distributed database system. It is a collection of multiple, logically interrelated databases distributed over a computer network.

10. Which one of the following is not true?
a) multiple hostnames may correspond to a single IP address
b) a single hostname may correspond to many IP addresses
c) a single hostname may correspond to a single IP address
d) none of the mentioned
View Answer

Answer: c
Explanation: It need not be that a single hostname will correspond to a ip address. For example facebook.com and fb.com both correspond to same ip address. So there can be multiple hostnames for a single ip address.

1. DHCP (dynamic host configuration protocol) provides __________ to the client.
a) IP address
b) MAC address
c) Url
d) None of the mentioned
View Answer

Answer: a
Explanation: We use DHCP to allow the hosts to acquire their ip addresses dynamically which is better than visiting each and every host on the network and configure all of this information manually.

2. DHCP is used for ________
a) IPv6
b) IPv4
c) Both IPv6 and IPv4
d) None of the mentioned
View Answer

Answer: c
Explanation: DHCP is used for both IPv4 and IPv6 addressing. With DHCP you get to let the hosts know about the change dynamically, and hosts update their info themselves.

3. The DHCP server _________
a) maintains a database of available IP addresses
b) maintains the information about client configuration parameters
c) grants a IP address when receives a request from a client
d) all of the mentioned
View Answer

Answer: d
Explanation: Whenever a DHCP server gets a request from a client it responds with a DHCP offer containing IP address being offered, network mask offered, the amount of time that the client can use and keep it, the ip address of the DHCP server making this offer.

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4. IP assigned for a client by DHCP server is
a) for a limited period
b) for an unlimited period
c) not time dependent
d) none of the mentioned
View Answer

Answer: a
Explanation: The IP address offered to a client is only for a limited period of time. There is actually a certain amount of time that the client can use and keep this IP address.

5. DHCP uses UDP port _________ for sending data to the server.
a) 66
b) 67
c) 68
d) 69
View Answer

Answer: b
Explanation: 67 is the UDP port number that is used as the destination port of a server. Whereas UDP port number 68 is used by the client.

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6. The DHCP server can provide the _______ of the IP addresses.
a) dynamic allocation
b) automatic allocation
c) static allocation
d) all of the mentioned
View Answer

Answer: d
Explanation: When a host acquires multiple offers of IP addresses from different DHCP servers, the host will broadcast a dhcp request identifying the server whose offer has been accepted.

7. DHCP client and servers on the same subnet communicate via _________
a) UDP broadcast
b) UDP unicast
c) TCP broadcast
d) TCP unicast
View Answer

Answer: a
Explanation: DHCP actually employs a connectionless service, which is provided by UDP, since TCP is connection oriented. It is implemented with two UDP port numbers 67 and 68 for its operations.

8. After obtaining the IP address, to prevent the IP conflict the client may use _________
a) internet relay chat
b) broader gateway protocol
c) address resolution protocol
d) none of the mentioned
View Answer

Answer: c
Explanation: ARP abbreviation for address resolution protocol is used for mapping IP addresses to MAC addresses that are present in the local network.

9. What is DHCP snooping?
a) techniques applied to ensure the security of an existing DHCP infrastructure
b) encryption of the DHCP server requests
c) algorithm for DHCP
d) none of the mentioned
View Answer

Answer: a
Explanation: DHCP snooping is a security feature that is used in OS of a network in the layer 2. This technology prevents unauthorized DHCP servers offering IP addresses to DHCP clients.

10. If DHCP snooping is configured on a LAN switch, then clients having specific ______ can access the network.
a) MAC address
b) IP address
c) Both MAC address and IP address
d) None of the mentioned
View Answer

Answer: c
Explanation: The DHCP snooping is done to prevent unauthorized IP addresses being offered by unauthorized servers. This features allows only specific mac addresses and IP addresses to access the network.

1. IPSec is designed to provide security at the _________
a) Transport layer
b) Network layer
c) Application layer
d) Session layer
View Answer

Answer: b
Explanation: IPSec is a set of protocols used to provide authentication, data integrity and confidentiality between two machines in an IP network. In the TCP/IP model, it provides security at the IP layer i.e. the network layer.

2. In tunnel mode, IPSec protects the ______
a) Entire IP packet
b) IP header
c) IP payload
d) IP trailer
View Answer

3. Which component is included in IP security?
a) Authentication Header (AH)
b) Encapsulating Security Payload (ESP)
c) Internet key Exchange (IKE)
d) All of the mentioned
View Answer

Answer: d
Explanation: AH ensures that there is no retransmission of data from an unauthorized source, and protects against data tampering. ESP provides with content protection and ensures that there is integrity and confidentiality for the message. IKE is used to make sure that only the intended sender and receiver can access the message.

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4. WPA2 is used for security in _______
a) Ethernet
b) Bluetooth
c) Wi-Fi
d) Email
View Answer

Answer: c
Explanation: WPA2 or WiFi Protected Access 2 is a security protocol used to provide users and firms with strong data security and protection for their wireless networks (WiFi) to give them confidence that only authorized users can access their network.

5. An attempt to make a computer resource unavailable to its intended users is called ______
a) Denial-of-service attack
b) Virus attack
c) Worms attack
d) Botnet process
View Answer

Answer: a
Explanation: In a Denial of Service attack, the attacker won’t let the victims access the network by using a certain method that ensures that an essential network resource is unavailable to the victim. The methods that the attacker can use are vulnerability attack, bandwidth flooding and connection flooding.

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6. Extensible authentication protocol is authentication framework frequently used in ______
a) Wired personal area network
b) Wireless networks
c) Wired local area network
d) Wired metropolitan area network
View Answer

Answer: b
Explanation: The Extensible Authentication Protocol (EAP) is an authentication protocol used to connect a network node to the Internet. It designed through extending the methods used by the Point-to-Point Protocol for authentication.

7. Pretty good privacy (PGP) is used in ______
a) Browser security
b) Email security
c) FTP security
d) WiFi security
View Answer

Answer: b
Explanation: PGP is an encryption method used in e-mail security to encrypt and decrypt the content of an e-mail transmitted over the internet. It makes sure that the message cannot be stolen by other unauthorized users.

8. PGP encrypts data by using a block cipher called ______
a) International data encryption algorithm
b) Private data encryption algorithm
c) Internet data encryption algorithm
d) Local data encryption algorithm
View Answer

Answer: a
Explanation: The IDEA was designed in 1991 by Xuejia Lai and James Massey. Before IDEA, PGP used the cipher method BassOmatic.

9. When a DNS server accepts and uses incorrect information from a host that has no authority giving that information, then it is called _________
a) DNS lookup
b) DNS hijacking
c) DNS spoofing
d) DNS authorizing
View Answer

Answer: c
Explanation: In DNS spoofing, also known as DNS cache poisoning, an attacker gets the valid credentials from a victim by spoofing the intended resource, and tricking the victim to give his/her valid authorization credentials.

1. A ___________ is an extension of an enterprise’s private intranet across a public network such as the internet, creating a secure private connection.
a) VNP
b) VPN
c) VSN
d) VSPN
View Answer

Answer: b
Explanation: VPN provides enhanced security and online anonymity to users on the internet. It is also used to unblock websites that are unavailable in certain regions.

2. When were VPNs introduced into the commercial world?
a) Early 80’s
b) Late 80’s
c) Early 90’s
d) Late 90’s
View Answer

Answer: d
Explanation: VPNs were first introduced in the year 1996. Then as the internet started to get popularized, the need for connection security increased. VPN was a great solution to this, and that’s when VPNs were implemented in the commercial world.

3. What protocol is NOT used in the operation of a VPN?
a) PPTP
b) IPsec
c) YMUM
d) L2TP
View Answer

Answer: c
Explanation: PPTP is a tunneling protocol which was initially used for the creation of VPNs. IPSec is used in encrypting the traffic flowing in the VPN. L2TP is used to tunnel all the L2 traffic on the VPN.

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4. Which of the following statements is NOT true concerning VPNs?
a) Financially rewarding compared to leased lines
b) Allows remote workers to access corporate data
c) Allows LAN-to-LAN connectivity over public networks
d) Is the backbone of the Internet
View Answer

Answer: d
Explanation: VPNs are not the backbone of the Internet as they are just a method to create private intranets on the internet. They are used for enhancing the connection security for the users.

5. Traffic in a VPN is NOT ____________
a) Invisible from public networks
b) Logically separated from other traffic
c) Accessible from unauthorized public networks
d) Restricted to a single protocol in IPsec
View Answer

Answer: c
Explanation: Traffic in a VPN is not accessible from any unauthorized public networks because it is secured with the masking IP address. This provides the benefit of access to blocked resources to the users.

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6. VPNs are financially speaking __________
a) Always more expensive than leased lines
b) Always cheaper than leased lines
c) Usually cheaper than leased lines
d) Usually more expensive than leased lines
View Answer

Answer: c
Explanation: The services of a VPN are cheaper for moderate to large scale institutional networks than the services of leased lines. Though for a small scale network, it does not prove to be as beneficial as the costs are not reduced to a great degree as compared to leased lines.

7. Which layer 3 protocols can be transmitted over an L2TP VPN?
a) Only IP
b) Only IPX
c) Only ICMP
d) IP and IPX
View Answer

Answer: d
Explanation: L2TP stands for Layer 2 Tunneling Protocol. It is used to tunnel all the L2 traffic on an IP network and is able to transmit network layer’s IP and IPX protocol data.

8. ESP (Encapsulating Security Protocol) is defined in which of the following standards?
a) IPsec
b) PPTP
c) PPP
d) L2TP
View Answer

Answer: a
Explanation: ESP is a security component of IPSec. ESP provides content protection and ensures that there is integrity and confidentiality of the message. The other security components of IPSec are Authentication Header and Internet Key Exchange.

9. L2F was developed by which company?
a) Microsoft
b) Cisco
c) Blizzard Entertainment
d) IETF
View Answer

Answer: b
Explanation: L2F stands for Layer 2 Forwarding protocol. It was designed by Cisco to tunnel PPP traffic, helping create VPNs over the internet.

10. Which layer of the OSI reference model does PPTP work at?
a) Layer 1
b) Layer 2
c) Layer 3
d) Layer 4
View Answer

Answer: b
Explanation: PPTP stands for Point-to-Point Tunneling Protocol. PPTP is a tunneling protocol that was primitively used to create VPNs. It is no longer used for VPNs due to the lack of security it provides.

11. Which layer of the OSI reference model does IPsec work at?
a) Layer 1
b) Layer 2
c) Layer 3
d) Layer 4
View Answer

Answer: c
Explanation: IPSec is a set of protocols used to provide authentication, data integrity and confidentiality between two machines in an IP network. It operates in the network layer.

1. Telnet protocol is used to establish a connection to __________
a) TCP port number 21
b) TCP port number 22
c) TCP port number 23
d) TCP port number 25
View Answer

Answer: c
Explanation: TCP port 21 is used for FTP, TCP port 22 is used for SSH and TCP port 25 is used for SMTP. Telnet provides access to a command line interface on a remote computer using the TCP port number 23.

2. Which one of the following is not true?
a) telnet defines a network virtual terminal (NVT) standard
b) client programs interact with NVT
c) server translates NVT operations
d) client can transfer files using to remote server using NVT
View Answer

Answer: d
Explanation: The client can use the NVT only to interact with the programs already present on the remote server, not to transfer files to it. To transfer files, an FTP connection has to be used.

3. All telnet operations are sent as ________
a) 4 bits
b) 8 bits
c) 16 bits
d) 32 bits
View Answer

Answer: b
Explanation: Telnet provides a bi-directional, 8-bit byte oriented communications facility through which operations are sent as 8-bit bytes for the server to interpret.

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4. AbsoluteTelnet is a telnet client for _______ Operating system.
a) windows
b) linux
c) mac
d) ubuntu
View Answer

Answer: a
Explanation: AbsoluteTelnet was originally released in 1999. It was developed by Brian Pence of Celestial Software.

5. The decimal code of Interpret as Command (IAC) character is _______
a) 252
b) 253
c) 254
d) 255
View Answer

Answer: d
Explanation: If we want that a character be interpreted by the client instead of server, we use the IAC character. If IAC is followed by any other code than IAC, the client interprets it as a character.

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6. Which of the following is true for character mode operation of telnet implementation?
a) each character typed is sent by the client to the server
b) each character typed is discarded by the server
c) each character typed is aggregated into a word and then sent to the server
d) each character type is aggregated into a line and then sent to the server
View Answer

Answer: a
Explanation: In character mode, each character that the user is typing is immediately sent to the server which then interprets it only after the complete operation command is received.

7. In which mode of telnet, the client echoes the character on the screen but does not send it until a whole line is completed?
a) default mode
b) character mode
c) server mode
d) command mode
View Answer

Answer: a
Explanation: In the default mode, the client does not send each character typed by the user to the server, thus saving the amount of packet transmissions required for executing each operation. But the server has to remain idle until the client sends the completed line wasting a lot of time.

8. Which one of the following is not correct?
a) telnet is a general purpose client-server program
b) telnet lets user access an application on a remote computer
c) telnet can also be used for file transfer
d) telnet can be used for remote login
View Answer

Answer: c
Explanation: File Transfer Protocol is used for file transfer. Telnet provides access to the command-line interface on a remote host.

1. Which of the following is false with respect to TCP?
a) Connection-oriented
b) Process-to-process
c) Transport layer protocol
d) Unreliable
View Answer

Answer: d
Explanation: TCP is a transport layer protocol that provides reliable and ordered delivery of a stream of bytes between hosts communicating via an IP network.

2. In TCP, sending and receiving data is done as _______
a) Stream of bytes
b) Sequence of characters
c) Lines of data
d) Packets
View Answer

Answer: a
Explanation: TCP provides stream oriented delivery between hosts communicating via an IP network and there are no message boundaries. TCP can concatenate data from a number of send () commands into one stream of data and still transmit it reliably.

3. TCP process may not write and read data at the same speed. So we need __________ for storage.
a) Packets
b) Buffers
c) Segments
d) Stacks
View Answer

Answer: b
Explanation: A TCP receiver has a receive buffer that is used to store the unprocessed incoming packets in case the sender is sending packets faster than the processing rate of the received packets.

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4. TCP groups a number of bytes together into a packet called _______
a) Packet
b) Buffer
c) Segment
d) Stack
View Answer

Answer: c
Explanation: A segment may be collection of data from many send () statements. TCP transmits each segment as a stream of bytes.

5. Communication offered by TCP is ________
a) Full-duplex
b) Half-duplex
c) Semi-duplex
d) Byte by byte
View Answer

Answer: a
Explanation: Data can flow both the directions at the same time during a TCP communication hence, it is full-duplex. This is the reason why TCP is used in systems that require full-duplex operation such as e-mail systems.

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6. To achieve reliable transport in TCP, ___________ is used to check the safe and sound arrival of data.
a) Packet
b) Buffer
c) Segment
d) Acknowledgment
View Answer

Answer: d
Explanation: Acknowledgment mechanism is used to check the safe and sound arrival of data. The sender actively checks for acknowledgement from the receiver and once a specific time period has passed, it retransmits the data.

7. In segment header, sequence number and acknowledgement number fields refer to _______
a) Byte number
b) Buffer number
c) Segment number
d) Acknowledgment
View Answer

Answer: a
Explanation: As TCP has to ensure ordered delivery of packets, sequence number and acknowledgement number are used to identify the byte number of the packet in the stream of bytes being transmitted.

8. Suppose a TCP connection is transferring a file of 1000 bytes. The first byte is numbered 10001. What is the sequence number of the segment if all data is sent in only one segment?
a) 10000
b) 10001
c) 12001
d) 11001
View Answer

Answer: b
Explanation: The sequence number given to first byte of a segment, with respect to its order among the previous segments, is the sequence number of that segment.

9. Bytes of data being transferred in each connection are numbered by TCP. These numbers start with a _________
a) Fixed number
b) Random sequence of 0’s and 1’s
c) One
d) Sequence of zero’s and one’s
View Answer

Answer: d
Explanation: One might expect the sequence number of the first byte in the stream to be 0, or 1. But that does not happen in TCP, Instead, the sender has to choose an Initial Sequence Number (ISN), which is basically a random 32 bit sequence of 0’s and 1’s, during the connection handshake.

10. The value of acknowledgement field in a segment defines _______
a) sequence number of the byte received previously
b) total number of bytes to receive
c) sequence number of the next byte to be received
d) sequence of zeros and ones
View Answer

Answer: c
Explanation: The acknowledgement field in a segment defines the sequence number of the byte which is to be received next i.e. sequence number of byte that the sender should transmit next.

1. Which of the following is false with respect to UDP?
a) Connection-oriented
b) Unreliable
c) Transport layer protocol
d) Low overhead
View Answer

Answer: a
Explanation: UDP is an unreliable, connectionless transport layer protocol that provides message-based data transmission. TCP is an example of connection-oriented protocols.

2. Return value of the UDP port “Chargen” is _______
a) String of characters
b) String of integers
c) Array of characters with integers
d) Array of zero’s and one’s
View Answer

Answer: a
Explanation: Using Chargen with UDP on port 19, the server sends a UDP datagram containing a random number of characters every time it receives a datagram from the connecting host. The number of characters is between 0 and 512.

3. Beyond IP, UDP provides additional services such as _______
a) Routing and switching
b) Sending and receiving of packets
c) Multiplexing and demultiplexing
d) Demultiplexing and error checking
View Answer

Answer: d
Explanation: De-multiplexing is the delivering of received segments to the correct application layer processes at the recipients end using UDP. Error checking is done through checksum in UDP.

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4. What is the main advantage of UDP?
a) More overload
b) Reliable
c) Low overhead
d) Fast
View Answer

Answer: c
Explanation: As UDP does not provide assurance of delivery of packet, reliability and other services, the overhead taken to provide these services is reduced in UDP’s operation. Thus, UDP provides low overhead, and higher speed.

5. Port number used by Network Time Protocol (NTP) with UDP is ________
a) 161
b) 123
c) 162
d) 124
View Answer

Answer: b
Explanation: The Network Time Protocol is a clock synchronization network protocol implemented by using UDP port number 123 to send and receive time stamps.

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6. What is the header size of a UDP packet?
a) 8 bytes
b) 8 bits
c) 16 bytes
d) 124 bytes
View Answer

Answer: a
Explanation: The fixed size of the UDP packet header is 8 bytes. It contains four two-byte fields: Source port address, Destination port address, Length of packet, and checksum.

7. The port number is “ephemeral port number”, if the source host is _______
a) NTP
b) Echo
c) Server
d) Client
View Answer

Answer: d
Explanation: Port numbers from 1025 to 5000 are used as ephemeral port numbers in Windows Operating System. Ephemeral port numbers are short-lived port numbers which can be used for clients in a UDP system where there are temporary clients all the time.

8. “Total length” field in UDP packet header is the length of _________
a) Only UDP header
b) Only data
c) Only checksum
d) UDP header plus data
View Answer

Answer: d
Explanation: Total length is the 16 bit field which contains the length of UDP header and the data. The maximum value of the Total length field and the maximum size of a UDP datagram is 65,535 bytes (8 byte header + 65,527 bytes of data).

9. Which is the correct expression for the length of UDP datagram?
a) UDP length = IP length – IP header’s length
b) UDP length = UDP length – UDP header’s length
c) UDP length = IP length + IP header’s length
d) UDP length = UDP length + UDP header’s length
View Answer

Answer: a
Explanation: A user datagram is encapsulated in an IP datagram. There is a field in the IP header that defines the total length of the IP packet. There is another field in the IP header that defines the length of the header. So if we subtract the length of the IP header that is encapsulated in the IP packet, we get the length of UDP datagram.

10. The ______ field is used to detect errors over the entire user datagram.
a) udp header
b) checksum
c) source port
d) destination port
View Answer

Answer: b
Explanation: Checksum field is used to detect errors over the entire user datagram. Though it is not as efficient as CRC which is used in TCP, it gets the job done for the UDP datagram as UDP doesn’t have to ensure the delivery of the packet.

UNIT 2

1. Guided media is also known as_______.
A. bound media
B. guided media
C. unguided media
D. none of the above

Answer A. bound media

2. How many forms in twisted pair cable?
A. 2
B. 4
C. 3
D. non

Answer A. 2

3. UTP stands for…
A. unshielded transport pair cable
B. unshielded twisted pair cable
C. unshielded transmission pair cable
D. unshielded twisted pair control

Answer B. unshielded twisted pair cable

4. What is the frequency range of UTP cable?
A. 100Hz to 5MHz
B. 100MHz to 5MHz
C. 100Hz to 5Hz
D. 1000Hz to 5MHz

Answer A. 100Hz to 5MHz

5. What are the disadvantages of UTP cable?
A. costly
B. easy to use
C. flexible
D. easy to install

Answer A. costly

6. STP stands for…
A. shielded twisted pair cable
B. shielded twisted pair connectors
C. shielded transport pair cable
D. shielded transport pair connectors

Answer A. shielded twisted pair cable

7. Which of the following cable come into guided media?
A. coaxial cable
B. twisted pair cable
C. fiber optic cable
D. all of the above

Answer D. all of the above

8. Which of the following cable doesn’t come into guided media?
A. coaxial cable
B. twisted pair cable
C. fiber optic cable
D. microwave

Answer D. microwave

9. Which of the following waves come into unguided media?
A. microwave
B. infrared wave
C. radio wave
D. all of the above

Answer D. all of the above

10. Which of the following waves do not come into unguided media?
A. microwave
B. infrared wave
C. radio wave
D. laser

Answer D. laser

11. What is the frequency range of the coaxial cable?
A. 100KHz to 500MHz
B. 100MHz to 500MHz
C. 1000KHz to 500MHz
D. 10MHz to 50MHz

Answer A. 100KHz to 500MHz

12. How many types of coaxial cable?
A. 2
B. 3
C. 4
D. 5

Answer A. 2

13. which of the following are coaxial cable-layers?
A. thinnet
B. thicknet
C. copper
D. A and B both

Answer D. A and B both

14. Thicknet can carry signal for_____meters.
A. 500m
B. 1000m
C. 100m
D. 200m

Answer A. 500m

15. How many connectors are used for coaxial cable?
A. 3
B. 5
C. 4
D. 2

Answer C. 4

16. Which of the following connectors dosen’t come into
coaxial cable connectors?
A. barrel
B. BNC
C. T-connectors
D. UTP

Answer D. UTP

17. BNC stands for…
A. Bayonet network connector
B. Bayonet network cable
C. Barrel network cable
D. nono of the above

Answer A. Bayonet network connector

18. BNC connectors are used to connect_____or_____with the NIC.
A. RG-58, RG-48
B. RG-62, RG-58
C. RG-58, RG-62
D. RJ-48 , RJ-49

Answer C. RG-58 , RG-62

19. BNC connectors is generally used in____and____topology.
A. bus, ring
B. tree, mesh
C. star, bus
D. mesh,bus

Answer C. star,bus

20. In the single fibers the core is__to__microns.
A. 9,15
B. 8,10
C. 4,6
D. 10,13

Answer B. 8,10

21. How many thicknesses of flexible coaxial cable?
A. 0.25 inch
B. 12 m
C. 15 m
D. 1.25 inch

Answer A. 0.25 inch

22. Which cable is used for thicknet coaxial cable?
A. RG-8
B. RG-9
C. RG-11
D. All of the above

Answer D. All of the above

23. How many components of fiber optic communication?
A. 3
B. 2
C. 4
D. 5

Answer A. 3

24. The waves are ranging between 1 and 300 GHz are called______.
A. infrared
B. microwave
C. laser
D. redio wave

Answer B. microwave

25. which of the following components are fiber optic communication?
A. light source
B. transmission medium
C. detector
D. all of the above

Answer D. all of the above

26. microwaves are_____.
A. unidirectional
B. directional
C. indirect
D. direct

Answer A. unidirectional

27. which of the following is not an application of microwaves?
A. cellular phones
B. satellite network
C. wireless clocks
D. wireless lans

Answer C. wireless clocks

28. Electromagnetic waves having frequencies from 300GHz to 400THz are called_____.
A. microwave
B. infrared wave
C. laser
D. radio wave

Answer B. infrared wave

29. Infrared waves are useful for_______.
A. high range communication
B. short-range frequency
C. short-range communication
D. long range communication

Answer C. short range communication

30. Infrared waves are useless for______.
A. long-range communication
B. short-range communication
C. A and B
D. non of thje above

Answer A. long range communication

31. The remote controls used on television, VCRs Based on______.
A. laser we’ve
B. microwave
C. radio wave
D. infrared wave

Answer D. infrared wave

32. LASER stands for…
A. light amplification by simuleted mission of radiation
B. light amplification by stimulated emission of radiation
C. long amplification by stimulated emission of radiation
D. none of the above

Answer C. long amplification by stimuleted emission of radiation

33. On a LAN, laser light technology is similar to_____technlogy.
A. infrared
B. microwave
C. laser
D. redio wave

Answer A. infrared

34. L in laser stands for…
A. laser
B. light
C. long
D. limited

Answer B. light

35. ______consist of 2 conductors twisted round each other.
A. fiber-optic cable
B. coaxial cable
C. microwave cable
D. twisted-pair cable

Answer D. twisted-pair cable

36. Category 5 UTP cables______category 1 cables.
A. transmit data at higher rates than
B. transmit data at lower rates then
C. have less twisted per foot then
D. non of the above

Answer A. transmit data at higher rates than

37. The most frequently used UTP connector is_____.
A. category 5 connector
B. EIA 232
C. RJ45
D. JR45

Answer C. RJ45

38. UTP is popular in LAN technology due to its_____.
A. flexibility
B. low cost
C. ease of installation
D. all of the above

Answer D. all of the above

39. The outer metallic sheath in coaxial cable functions as______.
A. a shield against noise
B. a second conductor
C. A and B
D. a unshield against noise

Answer C. A and B

40. The most popular connector used with_____cable is the BNC.
A. twisted-pair
B. shielded twisted-pair
C. coaxial
D. fiber-optic

Answer C. coaxial

41. The core of an optical fiber is_____.
A. glass
B. plastic
C. metal
D. A and B

Answer D. A and B

42. light travels at______in a vacuum.
A. 300,000km/s
B. 300,000miles/s
C. 300,000m/s
D. 186,000m/s

Answer A. 300,000km/s

43. Light travels at______in the atmosphere.
A. less than 186,000 miles/s
B. greater than 186,000 miles/s
C. 186,000 miles/s
D. 186,000m/s

Answer A. less than 186,000 miles/s

44. The angle of_____is measured with respect to the vertical axis.
A. incidence
B. reflection
C. refraction
D. all of the above

Answer D. all of the above

45. As a beam of light goes from the air into a body of water, its speed_____.
A. increases
B. decreases
C. remains the same
D. doubles

Answer B. decreases

46. There is no reflection until the angle of incidence is greater than the____angle.
A. horizontal
B. refractive
C. critical
D. vertical

Answer C. critical

45. when the angle of____is 90 degrees the angle of____is equal to the critical angle.
A. incidence; refraction
B. refraction; incidence
C. refraction; reflection
D. reflection; refraction

Answer . C. refraction; reflection

46. In which propagation mode is the core a uniform single-density?
A. multimode step-index
B. multimode graded-index
C. single mode
D. A and C

Answer . D. A and C

47. In which propagation mode the core of varying density is?
A. multimode step-index
B. multimode graded-index
C. single mode
D. A and B

Answer B. multimode graded-index

48. A beam of light is least distorted in a_____fiber.
A. multimode step-index
B. multimode graded-index
C. single-mode step-index
D. A and B

Answer C. single mode step-index

49. The____surrounds the_____in a fiber-optic cable.
A. fiber;cladding
B. core; fiber
C. core;claddind
D. cladding;core

Answer D. cladding;core

50. _____cable is not susceptible to most noise that is electrical.
A. twisted-pair
B. shielded twisted-pair
C. coaxial
D. fiber-optic

Answer D. fiber-optic

UNIT 3

1. WDM stands for?
a) Wave division multiplexing
b) Wavelength division multiplexing
c) Wavelength dependent multiplexing
d) Wave dependent multiplexing
View Answer

Answer: b
Explanation: It stands for Wavelength division multiplexing. It has same general architecture as FDM. FDM is frequency division multiplexing.

2. In TDM, the samples occupy adjacent time slots.
a) True
b) False
View Answer

Answer: a
Explanation: The statement is true. The TDM technique is based on sampling and they occupy adjacent slots and are transmitted in a sequence.

3. In this type of multiplexing time slots are preassigned to sources and fixed.
a) TDM
b) Synchronous TDM
c) Asynchronous TDM
d) FDM
View Answer

Answer: b
Explanation: TDM is time division multiplexing. Data rate of medium exceeds data rate of digital signal to be transmitted.

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4. Controlling the frequency is referred as _________
a) frequency modulation
b) hertz modulation
c) amplitude modulation
d) phase modulation
View Answer

Answer: a
Explanation: It is referred to as frequency modulation. When there is a change in frequency, it is referred to as frequency modulation.

5. A technique that can be a solution to the problem of synchronizing data sources.
a) framing
b) data link control
c) full link control
d) pulse stuffing
View Answer

Answer: d
Explanation: Pulse stuffing is a technique that can be a solution to the problem of synchronizing data sources. In pulse stuffing, the outgoing data rate is higher than sum of incoming rates.

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6. For voice, each channel contains a ___ word of digitized data.
a) 2
b) 1
c) 0
d) 4
View Answer

Answer: b
Explanation: In digital carrier systems, for voice each channel contains one word of digitized data. The data rate is 1.544 Mbps. Five out of six frames have 8 bit PCM samples.

7. Many time slots are wasted in __________
a) TDM
b) Synchronous TDM
c) Asynchronous TDM
d) FDM
View Answer

Answer: b
Explanation: In Synchronous TDM, many time slots are wasted. Other techniques can help overcome this problem.

8. A technique that allocates time slots dynamically.
a) TDM
b) WDM
c) Dynamic TDM
d) Statistical TDM
View Answer

Answer: d
Explanation: Statistical TDM assigns time slots dynamically. They are allocated based on demand. Multiplexer scans input lines and collects data until the frame is full.

9. A system in which two channels are dedicated to transfer data.
a) TV
b) Cable
c) Modem
d) Cable modem
View Answer

Answer: d
Explanation: A cable modem has two dedicated channels from cable TV provider dedicated to data transfer. One in each direction.

10. In this technique, there is a link between subscriber and network and a local loop.
a) SSDL
b) DSDL
c) ASDL
d) TSDL
View Answer

Answer: c

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