Computer Networking
Introduction to computer networking
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Computer network is a collection of computers that are interconnected for the purpose of sharing
data and resources.
Connections between computers are either using cables or wireless.
Advantages of computer networking
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Easy data sharing Network drive is used to store and share data.
 So need to store data on each computer.
Easy access to data Data stored on local devices may be lost with no backup.
 Storing data on network area solves this problem.
Cost effectiveness Can share hardware devices like printer, modem, scanners over a network. This reduces cost.
No need to keep hard copies of document Over a network we share soft copies of documents.
Types of computer networks
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Personal Area Network (PAN)
Local Area Network (LAN)
Metropolitan Area Network (MAN)
Wide Area Network (WAN)
Personal Area Network (PAN)
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Interconnection of personal devices like laptop, mobile phone, smart phone, etc.
Local Area Network (LAN)
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group of computers connected with each other in small places such as school, hospital,
apartment etc.
Metropolitan Area Network (MAN)
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Larger than LAN
Multiple buildings of large companies, school campuses, cities or towns
Wide Area Network (WAN)
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No geographic limit.
Connect computers and other devices located at distant places.
Example- Internet.
Network Topologies
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It refers to ways in which different devices are arranged- either physically or logically.
Physical topology is physical arrangement of devices and cables.
Logical topology is the way the information flows between various components in a network.
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Each computer is connected to a main cable. Cable is called backbone.
One of the computer acts as server. Server process the request and sends data to other
devices.
Advantages- easy to connect, less expensive because less cable is needed, if node breaks
network is not affected.
Disadvantages- if cable breaks network fails, difficult to repair.
Bus
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Star
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Ring
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Each computer is connected to central server called hub.
Advantages- set up cost is low, easy to add new nodes to the network, failure between
computer and hub does not affect the network.
Disadvantages- if hub fails whole network will fail, more cable is needed so it is expensive.
Mesh
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Computers connected in ring structure. Data travels in one direction until it reaches
destination.
Advantages- easy to detect faults, can handle large amount of data over long distances.
Disadvantages- difficult to add a new device to network, if a computer fails whole network
will fail, wiring is costly.
Each device connected to every other device.
Advantages- if a system fails network is not affected, can handle large amount of data,
security is high.
Disadvantages- high cabling cost, installation and reconfiguring is difficult.
5.
Tree
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Only one connection between two nodes.
Also called star-bus topology.
Central hub or root node is at top. It is connected to one or two nodes below it.
Advantages- more devices can be added, if a computer fails only its nodes will shut down but
network wont fail.
Disadvantages- cabling cost, if central node fails network will shut down, maintenance is
difficult.