Local Area Network (LAN) allows computers and devices within a limited geographic area like a home, office, or small group of buildings to share resources. A LAN connects desktops, laptops, printers, servers and other devices together wired or wirelessly so users can share files, applications, and peripherals. Common LAN technologies include Ethernet, Token Ring, and FDDI. LANs improve collaboration and productivity by allowing seamless file sharing, network access to applications, and more.

1. Working of Local Area Network
( LAN )
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2. Local Area Network (LAN)
• A Local Area Network (LAN) is best defined in terms of
the purpose it is meant to serve rather then in terms of
how its works
• LAN is a digital communication system capable of
interconnecting all the computers and terminals with in a
limited area such as an office building or factory or a
campus and share memory of the central computer
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3. Fig.1 3

4. Local Area Network (LAN)
Fig.2 4

5. Local Area Network (LAN)
• Computers in a LAN can communicate over twisted pairs
coaxial or fiber optic cables
• Twisted pairs provide the lowest rate of data transmission
but have the advantage that they are already installed in
may office buildings
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6. Local Area Network (LAN) Cables & Connectors
Fig.3 6

7. Local Area Network (LAN)
The two main purposes of the LAN are
• To link the computers within an organization or campus
so that may share expensive peripheral devices, for
example high speed printers or magnetic disks holding
the data base
• To allow these computers to communicate with each
other
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8. Local Area Network (LAN) in a Campus
Fig.4 8

9. A Local Area Network (LAN) connected by a
HUB
Fig.5 9

10. A complex Local Area Network (LAN)
Fig.6 10

11. A minimum Configuration of Local Area
Network (LAN)
Fig.7 11

12. LAN Network Interface Card (NIC)
• A network card, network adapter, LAN Adapter or NIC
(network interface card) is a piece of computer hardware
designed to allow computers to communicate over a
computer network
• It is both an OSI layer1 (physical layer) and layer 2 (data
link layer) device, as it provides physical access to a
networking medium and provides a low-level addressing
system through the use of Medium Access Control
(MAC) addresses
• It allows users to connect to each other either by using
cables or wirelessly
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13. A Giga Bit Local Area Network (LAN) Card
Fig.8 13

14. A Local Area Network (LAN) with a Switch
Fig.9 14

15. Local Area Network (LAN) Cables
Fig.10 9EC606A.34 15

16. Local Area Network (LAN) Structural Cables
Fig.11 9EC606A.34 16

17. Local Area Network (LAN)
• LAN server has applications and data storage that are shared
in common by multiple computer users
• A local area network may serve as few as two or three users)
or as many as thousands of users
• Major local area network technologies are:
Ethernet, Token ring, FDDI (used to serve thousands of
users)
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18. Local Area Network (LAN)
• Ethernet is by far the most commonly used LAN
technology
• A number of corporations use the Token Ring
technology
• FDDI (Fibre Distributed Data Interface is sometimes
used as a backbone LAN interconnecting Ethernet or
Token Ring LANs
• Another LAN technology, ARCNET, once the most
commonly installed LAN technology, is still used in the
industrial automation industry
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19. Local Area Network (LAN)
• A group of application programs can be kept on the LAN
server
• Users who need an application frequently can download it
once and then run it from their local hard disk
• Users can order printing and other services as needed
through applications run on the LAN server
• A user can share files with others at the LAN server, read
and write access is maintained by a LAN administrator
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20. Local Area Network (LAN)
• A LAN server may also be used as a Web server if
safeguards are taken to secure internal applications and
data from outside access
• In some situations, a wireless LAN may be preferable to a
wired LAN because it is cheaper to install and maintain
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21. A wireless Local Area Network (LAN)
Fig.12 21

22. Summary
In this class, you have learnt about
• Local Area Network (LAN)
• Components of LAN
• Working of LAN
• LAN technologies
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23. QUIZ
1. The most commonly used LAN technology to
connect to thousands of users is
a) Token ring
b) Ethernet
c) FDDI
d) ARCNET
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24. QUIZ
2. A LAN spans with in a geographical area of about
a) Within a room
b) Within a building
c) Within a campus of few Km
d) All the above
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25. Frequently Asked Questions
1. Define Local Area Network (LAN)
2. Explain the working of LAN
3. List the features of LAN
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