COM165
BA118PDRM
2018677234
COMPUTER NETWORK
Purpose
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The purpose of a computer network is that of sharing resources and
data between computer systems and other devices.
Introduction
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Computer network is a telecommunication channel using which we
can share data with other computers or devices, connected to the
same network. It is also called Data Network. The best example of
computer network is Internet. A network must be able to meet certain
criteria which is performance, reliability and scalability.
Body
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Computer Networks: Performance
Transit time
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Response time
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It is the time taken to travel a message
from one device to another.
It is defined as the time elapsed
between enquiry and response.
Computer Networks: Reliability
It decides the frequency at which network failure take place. More the
failures are, less is the network's reliability.
Computer Networks: Security
It refers to the protection of data from any unauthorized user or
access. While travelling through network, data passes many layers of
network, and data can be traced if attempted. Hence security is also a
very important characteristic for Networks.
Properties of a Good Network
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Interpersonal Communication
We can communicate with each other efficiently and easily.
Example: emails, chat rooms, video conferencing, all of these
are possible because of computer networks.
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Resources can be shared
We can share physical resources by making them available on
a network such as printers, scanners and other devices.
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Sharing files, data
Authorized users are allowed to share the files on the same
network.
Basic Communication Model
A Communication model is used to exchange data between two
parties. For example: communication between a computer, server and
telephone (through modem).
COM165
BA118PDRM
2018677234
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Communication Model: Source
Data to be transmitted is generated by this device, example:
telephones, personal computers and other devices.
Communication Model: Transmitter
The data generated by the source system is not directly
transmitted in the form its generated. The transmitter
transforms and encodes the data in such a form to produce
electromagnetic waves or signals.
Communication Model: Transmission System
A transmission system can be a single transmission line or a
complex network connecting source and destination.
Communication Model: Receiver
Receiver accepts the signal from the transmission system and
converts it into a form which is easily managed by the
destination device.
Communication Model: Destination
Destination receives the incoming data from the receiver.
Data Communication
The exchange of data between two devices through a transmission
medium is called Data Communication. The data is exchanged in the
form of 0's and 1's. The transmission medium used is wired cable. For
data communication to occur, the communication device must be a
part of a communication system. Data Communication has two types Local and Remote.
Local
Local communication takes place when the communicating devices
are in the same geographical area, same building, or face-to-face.
Remote
Remote communication takes place over a distance i.e. the devices
are farther. The effectiveness of a data communication can be
measured through the following features
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Delivery
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Timeliness
Accuracy
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:
Delivery should be done to the correct
destination.
Delivery should be on time.
Data delivered should be accurate.
COM165
BA118PDRM
2018677234
Components of Data Communication
1. Message
2. Sender
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3. Receiver
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4. Medium
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5. Protocol
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It is the information to be delivered.
Sender is the person who is sending the
message.
Receiver is the person to whom the
message is being sent to.
It is the medium through which the
message is sent. For example: A
Modem.
These are some set of rules which
govern data communication.
Types of Computer Network
LAN (Local Area Network)
This is designed for small areas or work units such as an office, group
of buildings. These are preferred as they are easy to design and
troubleshoot. Personal computers and workstations are generally
preferred to have a LAN network
MAN (Metro political Area Network)
It is a bigger version of LAN and generally covers more area of
operation. When it covers a very large topographical area it means it
generally connects different LAN. MAN is extremely efficient for fast
communication, but they need a huge setup cost with more wires and
cables.
WAN (Wide Area Network)
It is easy to understand with the name itself. It can be a private or
public network. It has the potential to cover the entire country
Networking Devices
Conclusions
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Hub
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Switch
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Modem
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Router
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Bridge
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Repeater
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It is used to connect multiple network hosts and
even use for data transfer.
switch is responsible to filter and forward
the details.
the signal between digital data and analog
signal.
It is a device that helps in routing traffic from
one to another network.
It connects two subnetworks being a part of the
same network.
It is an electronic device primarily designed to
amplify the signals.
There are many different types of computer networks in the world
today. The options range from wired to wireless. The technology we
have today is truly amazing and will only continue to grow and connect
people from all over the world.