LANLocal Area NetworkBy Amal Wali 10DD

Contents Terms Advantages Disadvantages Cabled LAN, 3 types Essential hardware LAN topologies 3 structures of topologies Bus topology Star topology Wireless LAN WAN Data transmission Bibliography

Terms

Network: It is a collection of hardware components that are interconnected allowing information to be shared.

Standalone: It is a computer that does not require a network to function.

LAN: Local Area Network. Is a computer network that interconnects computers in a limited area, such as home, school or the library.

WAN: Wide Area Network. Is a telecommunication network that covers a wide area.

Clients: An application or system that accesses a service provided by a server.

Client/ Server Network: Involves numerous clients connecting to a single, central server.

Peer to peer network: Computer network in which each computer can act as a client or server for the other computers in the network.

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Advantages

Costly hardware can be shared. Network software is cheaper than purchasing individual

packages. Same files can accessed by all users. Messages can be sent between clients. Single internet connection can be shared by clients.

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Disadvantages

Expensive to set up and maintain. Viruses can spread to all computers in the network. More prone to hacking due to multiple points of access. If it is a star network, if the file server goes down, the

whole network will go down.

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3 types of Cabled LAN

Cabled LAN is not wireless, but requires wires. 1. Twisted pair: copper wires twisted into pairs.2. Coaxial cable: consist of copper or aluminum wire

surrounded by an insulating layer. 3. ITU-T G.hn: uses existing home wiring to create high

speed LAN.

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Essential hardware for a computer to be connected to LAN

Hub/Switch- interconnected multiple devices to LAN. Router- distribute shared internet access from WAN to

LAN. NIC (Network Interface Card) Cabling

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LAN topologies

LAN topologies is the layout pattern of interconnections of the numerous fundamentals of a computer network.

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3 Structures of Topologies

1. Bus Topology: use a common backbone to connect all devices.

2. Ring Topology: has two neighbors for communication purposes.

3. Star Topology: a central connection point named a “hub node” that may be network hub, switch or router.

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Bus Topology

1- Best suited for small networks. 2- Easy to handle and use.

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Star topology

Advantages:1- Easy to connect new devices. 2- Centralized management, helps monitor the network. 3- Failure of one nod does not affect the rest of the network. Disadvantages:1- If the central device fails, the rest of the network goes down. 2- The overall cost of the network is increased due to the use of hubs, a router or switch as a central device. 3- Performance and the number of nodes that can be added to the network all depend on the capacity of the central device.

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Wireless LAN

WLAN links two or more devices with a delivery method which is usually OFDM radio or spread-spectrum, and usually provides a connection through an access point to the wider internet. This gives the user to move around freely within the local coverage area and still be connected to the network. Norman Abramson created the first wireless computer connection network. WLAN is usually used instead of LAN because of its ease.

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WAN

Wide Area Network is a telecommunication network that covers a broad area. Businesses and governments use WANs to relay data among employees, clients, buyers, and suppliers from various different regions. WAN has made it possible for companies to communicate internally in methods which did not exist before. A user of WAN must subscribe to a service through a telecommunication provider. 

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Data Transmission 

Data transmission is the physical transfer of data over a point-to-point channel. Examples would include copper wires, optical fibers, wireless communication and storage media. The data is represented as an electromagnetic signal, such as an electrical voltage, radiowave, microwave or infrared signal. Digital communications is the transfer of discrete messages. These messages are either represented by a sequence of pulses by means of line code, or by using a digital modulation method. Data transmitted may be digital messages coming from a data source, or it may be an Analog signal such as a phone call or a video signal. The source of coding and decoding is carried out by codec equipment. 

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Bibliography

http://education.mu/forum/index.php?topic=306.0\ http://en.wikipedia.org/wiki/Computer_network#Wired_technologies http://www.facs.org/informatics/krusch.pdf http://www.google.ae/#hl=en&q=lan+topology&tbs=dfn:1&tbo=u&

sa=X&ei=8DaiT66OOs_PiAKJo-SLBw&ved=0CB0QkQ4&bav=on.2,or.r_gc.r_pw.r_qf.,cf.osb&fp=1592ac683e79e5a4&biw=1280&bih=923

http://compnetworking.about.com/od/networkdesign/a/topologies.htm

http://in.answers.yahoo.com/question/index?qid=20091015004612AAYDuar

http://www.ianswer4u.com/2011/05/star-topology-advantages-and.html#axzz1u5DpKSoA

http://en.wikipedia.org/wiki/Wireless_LAN http://en.wikipedia.org/wiki/Wide_area_network http://en.wikipedia.org/wiki/Data_transmission

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