Chapter -1
Networking & Telecommunication
1)
What
is communication?
Ans: Communication is sending and receiving information between two or more persons.
It is derived from the Latin word ‘communicare’.
2)
What
is telecommunication?
Ans: Telecommunication is a system of transmission of sounds, images, texts or
data in the form of electronic signals.
3)
What
is data communication?
Ans: Data communication system is the collection of hardware, software and
other devices that allows to exchange data, information and voice between two
or more devices through a wire or radio waves.
4)
Give
any two examples of data communication.
Ans: Any two examples of data
communication are:
a)
E-mail
b)
Chat
5)
Write
down the components of data communication.
Ans: The components of data communication are:
i) Data ii) Sender iii) Medium iv) Receiver v)
Protocol
6)
What
is medium?
Ans: A path through which the sender makes communication to the receiver is
known as medium.
7)
What
is communication protocol?
Ans: A communication protocol is a set of rules by which computers on the
network communicate with each other.
8)
List
the function of protocol.
Ans: The functions of protocol are
a.
Connection
control
b.
Helps
to transfer data either in connectionless or connection oriented.
c.
Sequencing
supports ordered delivery flow control and error control.
9)
Explain
TCP/IP suite.
Ans: The protocol of internet is
TCP/IP.
10) What is data
transmission mode?
Ans: Data transmission mode is the
way of transmission of data from one location to another.
11) Write down the modes of
data transmission.
Ans: The modes of data transmission are:
i) Simplex mode ii)Half duplex mode iii) Full Duplex Mode
12) Define simplex mode with
example.
Ans: The transmission mode in which transmission of data can take place in one
direction only is called simplex mode.
E.g.: Newspaper, Radio and Television.
13) Define half duplex mode
with example.
Ans: The transmission mode in which transmission of data can take place in both
directions but only in one direction at a time is called half duplex mode.
E.g.: Wireless handset and walkie-talkie.
14) What is full duplex
mode? Give example.
Ans: The transmission mode in which data can be transmitted in both the
directions simultaneously is called full duplex mode.
E.g.: Telephone, internet etc.
15) What is bandwidth?
Ans: Bandwidth can be defined as the maximum volume of data that can be
transmitted through a communication system.
16) How can we measure
bandwidth?
Ans: We can measure bandwidth in digital devices by bits per second and in
analogue devices by cycles per second or Hertz (Hz).
17) What is communication or
transmission medium?
Ans: Transmission
medium is a pathway
through which data are transmitted in a network.
18) Write down the types of
communication medium.
Ans: The types of communication medium are:
i) Guided or bounded or wired medium
ii) Unguided or unbounded or wireless medium
19) What is guided medium?
Ans: Guided
transmission medium are the cables that are tangible or have
physical existence and are limited by the physical geography. E.g.: twisted
pair cable, co-axial cable, fibre optics cable, etc.
20) What is unguided medium?
Ans: Unguided transmission medium is the transmission medium in which data signals
flow through the air or space without using any cables. E.g.: radio wave ,
microwave, infrared etc.
21) What is twisted pair
cable?
Ans: A pair of wires twisted with
each other is known as twisted pair cable. A set of four pairs of twisted wires
are bundled to form cable. These are the most common medium for LAN. Wires are
twisted with each other so as to reduce the interference.
Its types are:
a)
Unshielded
Twisted Pair Cable
b)
Twisted
Pair Cable
22) Differentiate between
shielded and unshielded twisted pair.
Ans: The differences between
shielded twisted pair and unshielded twisted pair are:
|
Shielded
twisted pair |
Unshielded twisted
pair |
|
· It is made up of
twisted pair wires with additional shielded and drain wires. |
· It is made up of
twisted pair wires without additional shielded and drain wires. |
|
· D-shell connectors are
used with shielded twisted pair. |
· RJ-45 connector is
commonly used with unshielded twisted pair. |
23) What is co-axial cable?
Ans: A wire with single ended
single reference where the central conductor carries the data signal.
24) What is fiber optics
cable?
Ans: Fiber optics cable is one of
the costlier cables used in data communication which uses light to carry a data
signal through the cable.
25) What are the uses of
fiber optic cable?
Ans: The uses of fiber optic cables
are:
a)
It
is used by many telecommunication companies to transmit telephone signal.
26) What is radio wave
transmission?
Ans: The transmission making use of
radio frequencies is termed as radio
wave transmission.
27) List the advantages of
radio wave transmission.
Ans: The advantages of
radio wave transmission are
a)
It
offers mobility.
b)
It
offers ease of communication over different terrain.
c)
It
offers freedom from land acquisition rights that are required for laying
repairing cables.
d)
It
provides cheaper than digging trenches for laying cables and maintaining
repeaters and cables if cables get broken by a variety of causes.
28) What is microwave
transmission?
Ans: The transmission which
involves sending signals from one microwave station to another is called microwave transmission.
29) What are the advantages
and disadvantages of microwave transmission?
Ans: The advantages of
microwave transmission are
a.
They
have the ability to communicate over oceans.
b.
It
offers ease of communication over difficult terrain.
The disadvantages of microwave
transmission are
a.
It
is an insecure communication.
b.
It
is susceptible to weather effects like rain, thunder storms etc.
30)
Differentiate
between radio wave and microwave communication media.
Ans: The differences between radio wave and microwave are as
follows:
|
Radio
wave |
Microwave |
|
· It is a form of
wireless communications in which signals are sent through radio frequency
waves. |
· It is a form of
wireless communication in which data signals are sent through pulses of
electromagnetic energy. |
|
· It provides low
bandwidth for data communication. |
· It provides higher
bandwidth for data communication. |
31) What is infrared
transmission?
Ans: Infrared transmissions are
just below visible transmission light which allows high speed data
transmission.
32) What is computer
network?
Ans: A group of interconnected computers through transmission media in order to
communicate and share resources like hardware, data and software.
33) Write down any four
advantages of computer network.
Ans: Any four advantages of computer network are as follows:
i) The computers on a network can share hardware devices like printer, hard
disk, scanner etc.
ii) File can be transferred from one computer to another in a network.
iii) Computers on the network can communicate with each other.
iv) Software packages can be shared between network connected computers.
34) Write any 4
disadvantages of computer network.
Ans: Any 4 disadvantages of
computer network are as follows:
i) The sharing of information may leak the privacy of other clients.
ii) If any computer system in a network gets affected by computer virus, there
is a big chance of spreading computer viruses on other computers on the
network.
iii) Computers on the network have to depend on the server computer for the
recourses.
iv) Data and information may be stolen by computer hackers if the security of
network is not reliable.
35) Computer Network reduces
expenses of an office. Justify this statement with an example.
Ans: Computer Network reduces
expenses of an office because computer on a network share different hardware
devices like printers, scanners, hard disk etc. And sharing those hardware
devicAes will reduces the expense of an office. For example if there are twenty
computers in an office, now for printing the data there is no need to buy
twenty printers individually rather than simple network the computer and
connect the printer on the network which helps in sharing of the one printer
among twenty computers which reduces the cost of buying nineteen printers
individually.
36) Computer Network reduces
operation cost. Justify.
Ans: Computer network reduces
operation cost because it takes short time to deliver information and communication
is also very cheap.
37) List the different
services of computer network. [
38) Mention the reasons of
keeping computers on the network.
Ans: The reasons of
keeping computers on the network are
a)
To
share hardware devices like printers, scanners, hard disks etc.
b)
To
share data, information and programs.
c)
To
communicate with each other.
39) Computer network makes
the world a small place. Justify.
Ans: Computer network makes the
world small place. It is true because in computer network we can know about the
events and things place outside or inside the country sitting within a room.
And we also can communicate with our relatives who are far away from us or has
gone to abroad for job or study. Therefore, computer network makes the world a
small place.
40) What are the hardware
and software components of a computer network?
Ans: The hardware
components of a network are:
a)
Computer
system (Server or Workstation)
b)
Network
connectors
c)
Network
cables
d)
NIC
e)
MODEM
The software components
of computer network are:
a)
Network
protocol
b)
Network
operating system
41) What is network
operating system?
Ans: Network operating system is a set of computer program that manages the
resources on network.
42) Give any four examples
of network operating system.
Ans: Any four examples of network
operating system are:
·
Novell
network
·
Microsoft
Windows NT
·
Linux
·
Unix
43) List the main goals of
computer network.
Ans: The main goals of computer network are
a.
Resource
sharing
b.
Reliability
c.
Communication
medium
d.
Access
to remote database
e.
Easy
data transfer
44) Define hardware
components.
Ans: Physical parts and devices
used to connect computers in the network environment are called hardware
components.
45) What is server?
Ans: A computer on a network that
allows a user to use it as a workstation and provides facilities of sharing its
resources to other computers on the network is dedicated server. A computer
that controls and provides hardware and software resources to other computers
on the network is called non-dedicated server.
46) Define dedicated and
non-dedicated server.
Ans: A server is the main computer
that provides services, data and other resources to the other computers in the
network environment. Network operating software used by server are Novell
Netware, Linux, Unix etc.
47) What is workstation?
Ans: Workstation is a computer network that utilizes network resources. Network
operating software used by workstation are Windows 98, Windows XP etc.
48) What is node?
Ans: Each computer or device of network is called node.
49) Define LAN.
Ans: A LAN is a network of
computers that are relatively near to each other and are connected in a way
that enables them to communicate by using cables and small wireless devices.
50) Define MAN.
Ans: A MAN is a network of computer
is computers which are spread over a metropolitan area such as within a city.
51) Define WAN.
Ans: A WAN is a network system of
connecting two or more computers generally across a wide geographical area such
as cities, districts, and countries.
52) Write down the
differences between LAN and MAN.
Ans:
|
LAN |
MAN |
|
It
is a network which covers small area i.e. within a room, building, or short
distance. |
It
is a network which covers an entire city or a big area. |
|
It
is controlled by a single organization. |
It
is controlled by single or group of organization. |
|
It
uses private connection media. |
It
uses private or public connection media. |
|
E.g.:
network in a school, college or cyber café. |
E.g.:
interconnection between different branches on same branch |
53) Write down the
differences between MAN and WAN.
Ans:
|
MAN |
WAN |
|
It
is a network which covers an entire city. |
It
is a network that covers large area or whole world. |
|
E.g.:
interconnection between different branches on same branch |
Eg.
Internet |
54) Write down any three
features of LAN.
Ans: Any three features of LAN are:
i) The diameter is not more than a few kilometres.
ii) LAN offers bandwidth of 10-100 Mbps.
iii) It is controlled by single organization.
55) Write down the features
of MAN.
Ans: The features of MAN are:
i) It covers a larger geographical area than LAN and connects larger number of
computer.
ii) It is owned by single or multiple organizations.
iii) It uses cable or wireless communication media to connect computers.
iv) It offers a number of network services compatible with bandwidth from 128
kbps to 1 Gbps.
56) Write down the features
of WAN.
Ans: The features of WAN are:
i) It is not restricted to a geographical location. It covers whole world.
ii) It uses satellite links or microwave system to connect several LANs and
MANs
iii) It is owned by multiple organizations.
iv) Data transmission in WAN is
slower than LANs and WANs
57) A WAN is composed of
LANs and MANs. Justify.
Ans: A WAN is composed of LANs and
MANs, it is true because big organization or offices may have branches within
different zones of Nepal or outside Nepal. The branches may have different LANs
and the computers on one branch may be connected with computers of other
branches through telephone lines or unbounded media. i.e. MAN. So, a WAN is
composed of LANs and MANs.
58) WANs are different
from LANs. Explain.
Ans: WANs are different from LANs
because WAN covers a larger geographical area whereas LAN covers very small
area. WAN is owned by multiple organizations whereas LAN is owned by single
organization. WAN uses public connections mediums such as telephone lines,
wireless technology etc.
59) What is network topology?
Ans: The arrangement or connection pattern of computers or nodes and other devices
of the network is called network topology.
60) List the three basic
topologies.
Ans: The three basic topologies are
a)
Bus
Topology
b)
Ring
Topology
c)
Star
Topology
61) What is bus topology?
Ans: The network topology in which computers and other devices are arranged in
linear format is called bus topology.
62) What is ring topology?
Ans: The network topology in which
computers are connected in the shape of a circle without any end points is
called ring topology.
63) What is star topology?
Ans: The network topology in which
all computers or other devices are connected through a central device through a
central device called hub or switch is called star topology.
64) What are the advantages
and disadvantages of ring topology?
Ans: The advantages of ring topology are :
i) It is easy it set up and configure.
ii) Each computer gets equal opportunity to access the network resources.
iii) It supports high data transmission rate.
iv) Performs better than a star
topology under heavy network load.
The disadvantages of ring topology are :
i)Failure of any cable or single computers may affect the entire network.
ii) It is difficult to detect the errors.
iii) Adding/removing the devices affect the entire network.
iv) Much slower than an Ethernet
network under normal load.
65) What are the advantages
and disadvantages of star topology?
Ans: The advantages of star topology are :
i) Easy to set up and configure.
ii) Failure of single computer or cable doesn’t affect the entire network.
iii) It is easy to find the fault.
iv) It is easy to extend to network by attaching new devices to the central
devices.
The disadvantages of star topology are:
i) It requires more cable in comparison of bus topology so it is more costly.
ii) Failure of central devices (hub or switch) break down the whole system.
66) What are the advantages
and disadvantages of bus topology?
Ans: The advantages of bus topology
are:
a)
It
is easy to set up computers and other devices in bus topology, because all the
devices are connected through a single wire.
b)
It
requires fewer cable media, so it is cheaper than other topologies.
c)
It
is easy to add new node to the network.
d)
Failure
of one workstation does not affect other computers on the network.
The disadvantages of
disadvantages are:
a)
The
whole network system collapses if the cable or backbone is damaged.
b)
The
network slows down if additional computers are connected.
c)
The
limited length of the cable in a network may restrict to connect the
workstation or devices.
d)
It
is difficult to find fault in this network topology.
67) What is network
architecture?
Ans: The arrangement of the
computers on the network which is based on the computing model is called
network architecture.
Its
types are
a)
Client
/ Server Network
b)
Peer
to Peer Network
68) What do you mean by
centralized computing network.
Ans: A centralized computing
network is a network in which a central host computer performs data processing
and storage on behalf of clients.
69) What is client/server
network?
Ans: Client/ server network is a type of network architecture that consist of
at least one server and one or more workstations.
70) What is peer-to-peer
network?
Ans: A peer to peer network is a group of computers that function as both
client and server.
71) Differentiate between
client/server network and peer-to-peer network.
Ans:
|
Client/Server network |
Peer-to-peer network |
|
It
consists of at least one server and one or more client. |
It
is a group of computers which function both as server and workstation. |
|
It
provides high security of data and other resources. |
It
provides no reliable security and might put data under risk. |
72) Write down the
disadvantages of client server.
Ans: The disadvantages are:
i) It is more expensive than peer-to-peer.
ii) A well-trained network administration is required to manage network.
73) Write down the
disadvantages of peer-to-peer.
Ans: The disadvantages are
i) The expansion of network is limited.
ii) It tends to slow down with network load.
74) What is router?
Ans: A router is an intelligent network device which connects multiple networks
that uses the same protocol and forwards data packets from one network to
another.
75) What is NIC?
Ans: A Network Interface Card (NIC) is the adapter through which the computer
is connected to the network.
76) Write down the function
of NIC.
Ans: The function of NIC is to
convert data into electronic signals and transfer them through cables and
vice-versa.
77) What is cable?
Ans: Cables are commonly used media of physical channel for transmitting data
between computers in network.
78) What is connector?
Ans: Connector is an interface between
the NIC of the computer and the cable that passes data between computers in
network.
79) Write down the main
function of NIC?
Ans: The main function of NIC is to act as the interface to connect the
computer to network and control the flow of data in computer network.
80) What is hub?
Ans: A hub is a network device that joins multiple computers or other network
devices together to form a segment of computer network.
81) What is switch?
Ans: A switch is a network device that connects computers, network devices and
LAN segments.
82) How is hub different
from switch?
Ans: A hub is different from switch
because a switch inspects data packets as they are received and can determine
source and destination device of that packets but hub broadcasts the electric
signals.
83) What is gateway?
Ans: Gateway is a dedicated server that connects two networks having dissimilar
communication protocols.
84) What is repeater?
Ans: Repeater is a device that amplifies the incoming signals, creates a copy
of it and transmits the signal on network.
85) What is MODEM?
Ans: MODEM is a device which is
used to transfer the data of one computer to another computer using telephone
lines.
86) What is the role of
MODEM in data transmission?
Ans: The role of MODEM in data
transmission is that it transfers data from one computer to another through
telephone line. It also converts the digital signal into analog and vice versa.
87) Write down the importance
of MODEM.
Ans: The importance of MODEM are:
·
Access
internet
·
Perform
modulation and demodulation process
·
Transfer
data from one computer to another through telephone line
88) What is modulation?
Ans: The process of translating
digital signals of a computer to analog signals, which are then transmitted
across the standard telephone lines, is known as modulation.
89) What is demodulation?
Ans: The process of translating
analog signals from a phone line and converts then into digital signals for the
computer is known as demodulation.
90) What is device driver?
Ans: Device driver is a program
that controls the functionality of the hardware device.
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