1 Working of Local Area Network ( LAN )

2 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 Local Area Network (LAN)

3 Fig.1

4 Local Area Network (LAN) Fig.2

5 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 Local Area Network (LAN)

6 Local Area Network (LAN) Cables & Connectors Fig.3

7 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 Local Area Network (LAN)

8 Local Area Network (LAN) in a Campus Fig.4

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

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

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

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

13 A Giga Bit Local Area Network (LAN) Card Fig.8

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

9EC606A.3415 Local Area Network (LAN) Cables Fig.10

9EC606A.3416 Local Area Network (LAN) Structural Cables Fig.11

17 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) Local Area Network (LAN)

18 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 Local Area Network (LAN)

19 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 Local Area Network (LAN)

20 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 Local Area Network (LAN)

21 A wireless Local Area Network (LAN) Fig.12

22 Summary In this class, you have learnt about Local Area Network (LAN) Components of LAN Working of LAN LAN technologies

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

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

25 Frequently Asked Questions 1.Define Local Area Network (LAN) 2.Explain the working of LAN 3.List the features of LAN