3. INTRODUCTION
A computer network or simply a
network is a collection of computers
and other hardware components
interconnected by communication
channels that allow sharing of
resources and information.
Computer network and technologies
that make communication between
networked computers possible
continue to drive computer hardware,
software and peripheral industries.
4. Cont…
The scope of communication has
been increasing significantly in the
knowledge era.
The expansion of related industries is
mirrored by growth in the numbers
and types of people using networks,
from the researcher to the home user.
5. Meaning and Definition
A Network can be defined as a group of
computers and other devices connected
in some ways so as to be able to
exchange the data.
“A combination of computer hardware,
cabling, network devices, and computer
software used together to allow
computers to communicate with each
other”.
The computers on a network may be
linked through cables, telephone lines,
radio waves, satellites or infrared rays
6. Need of Networking
File sharing: Networking of computers
helps the network users to share data
files.
Hardware sharing: Users can share
devices such as printers, scanners, CD-
ROM drives, hard drives, etc. Without
computer networks, device sharing is not
possible.
Application sharing: Applications can be
shared over the network, and this allows
implementing client/server applications.
7. Cont..
User communication: Networks allow
users to communicate using e-mail,
newsgroups, and video conferencing etc.
Network gaming: A lot of network games
are available, which allow multi-users to
play from different locations.
Voice over IP (VoIP): Voice over Internet
Protocol (IP) is a revolutionary change in
telecommunication which allows to send
telephone calls (voice, data) using the
standard Internet Protocol.
8. Types of Networks
◦ Personal Area Network(PAN)
◦ Storage Area Network (SAN)
◦ System Area Network (SAN)
◦ Local Area Network (LAN)
◦ Metropolitan Area Network (MAN)
◦ Wide area Network (WAN)
◦ Wi-Fi Wireless Connection
9. Personal Area Network (PAN)
A PAN is a network that is used for
communicating among computers and
computer devices (including telephones)
in close proximity of around a few meters
within a room.
It can be used for communicating
between the devices themselves, or for
connecting to a larger network such as
the Internet.
A personal Area network can be wired or
Wireless.
10. Cont…
PAN is a computer network used for
communication among computer
devices, including telephones and
digital assistants in proximity to an
Individual’s body.
Ex: Send Documents to the printer in
the office upstairs.
11. Storage Area Network (SAN)
A Storage Area Network connects
multiple servers and storage devices on
a single network.
A storage area network is any high
performance network whose primary
purpose is to enable storage devices to
communicate with computer systems
and with each other.
Many organizations operate perfectly
viable SANs that carry occasional
administrative and other application
traffic.
12. Cont…
Uses of SAN Network
Better disk utilization
Better availability of applications
A good solution for multiple
applications
To make the better usage of serves
A better recovery for a single
application
13. Cont…
Limitations
Precautions must be taken to prevent
unintentional access to the storage
devices.
Data corruption caused by unintended
access to the storage.
14. System Area Network
It Connects high performance computer
with high speed connections on a Cluster
Configuration.
It is also known as Cluster Area Network
Provides a reliable, connection-oriented
transfer between two endpoints.
provide very high-speed, low latency
access to information that is stored in
single or multiple databases.
15. System area networks (SAN) are high-
performance, connection-oriented
networks that link computer clusters.
16. System Area Networks deliver very
high bandwidth (more than 1
GB/second) with very low latency.
A SAN is typically used to interconnect
nodes within a distributed computer
system, such as a cluster.
SANs provide bulk data transfer
through a Remote Direct Memory
Access (RDMA) mechanism.
17. Local Area Network (LAN)
A LAN is a network that is used for
communicating among computer
devices, usually within an office,
building or home.
LAN enables the sharing of resources
such as files or hardware devices that
may be needed by multiple users.
It is limited in size, typically spanning a
few hundred meters, and no more
than a mile.
18. cont…
The speed ranges from 10 Mbps to 10
Gbps
Requires little wiring, typically a single
cable connecting to each device.
Lower cost compared to other
connections.
LAN may be wired or wireless.
Every LAN uses a set of rules that
19. Cont…
Advantages of LAN
Speed
Cost
Security
Email
Resource Sharing
Disadvantages of LAN
Expensive to install
Requires administrative install
File server may file
Cables may break
20. Metropolitan Network (MAN)
A MAN is a large computer network
that usually spans a city or a large
campus.
A MAN is optimized for a larger
geographical area than a LAN,
ranging from several blocks of
buildings to entire cities.
A MAN might be owned and operated
by a single organization, but it usually
will be used by many individuals and
organizations.
21. Cont…
High speed network to allow sharing
of regional resources.
It covers an area of between 5 and 50
km diameter.
Ex: Telephone Company network
22. Advantages of MAN network
MAN are that it provides a good
backbone for a large network and
provides greater access to WANs.
A Man usually encompasses several
blocks of a city or an entire city.
23. Disadvantages of MAN
More cable required for a man
connection from one place to another.
The larger the network becomes
difficult to manage.
It is difficult to make the system
secure from hackers and industrial
and geographical regions.
24. Wide Area Network
Multiple LAN’s are connected together
using devices such as bridges, routers
or gateways which enable them to
share the data.
The world’s most popular WAN is the
internet.
25. Advantages of WAN
Cover large Geographical area.
Shares software and resources with
connecting various workstations.
Shares information/data over large
areas.
Messages can be sent very quickly to
anyone else on the network.
26. Disadvantages of WAN
Comparatively Expensive.
Need a good firewall protection to
restrict from outsiders.
Security is a real issue when many
different people have the ability to use
information.
Information may not meet local needs
or interests.
27. Wireless Technology
Wireless technology has helped to
simplify networking by enabling
multiple computer users to
simultaneously share resources in a
home or business without additional or
Intrusive wiring.
These resources might include a
broadband Internet connection,
network printers, data files, and even
streaming audio and video.
28. Advantages of Wi-Fi
Advantages of WIFI
Convenience: The wireless nature of such
networks allows users to access network
resources from nearly any convenient
location within their primary networking
environment.
Mobility: With the emergence of public
wireless networks, users can access the
internet even outside their normal work
environment.
Productivity: Users connected to a wireless
network can maintain a nearly constant
affiliation with their desired network as they
move from place to place.
29. Cont…
Deployment: Initial setup of an
infrastructure-based wireless network
requires little more than a single
access point.
Expandability: Wireless networks can
serve a suddenly-increased number of
clients with the existing equipment.
30. Disadvantages of Wi-Fi
Security: To combat this consideration,
wireless networks may choose to
utilize some of the various encryption
technologies available.
Range: The typical range of a
common network with standard
equipment is on the order of tens of
meters.
31. Cont…
Reliability: Like any radio frequency
transmission, wireless networking
signals are subject to a wide variety of
interference, as well as complex
propagation effects that are beyond the
control of the network administrator.
Speed: The speed on most wireless
networks (typically 1-54 Mbps) is far
slower than even the slowest common
wired networks (100Mbps up to several
Gbps).
32. Applications of Networks
Information sharing: The depth of
knowledge and experience from a
group of people can be staggering.
Networking will provide many
opportunities to ask questions and
receive feedback.
Connections: information-sharing, joint
ventures, partnerships, and even
needs for services.
33. Cont…
Promotion: Whether promoting yourself
or your organization, having a large
network may assist you in moving your
career forward, promoting a new product
launch, or driving new members to your
organization.
Credibility: Improving your reputation
and finding support are also benefits of
networking. If you are successful at
networking, you might get a reputation
for being a person people will want to
talk to and get to know.
34. Cont…
Self Esteem: Making new friends and
socializing is an important aspect of
our human nature. Developing new
relationships leads to higher self
esteem and confidence.
35. Conclusion
The best known computer network is
the internet. Computer network
support applications such asaccess to
the world wide web, shared use of
application and storage servers,
printers, and fax machines, use of
email and instant messaging
applications and so on…