Transfer of Data in ICT

Transfer of Data in ICT systems

About Networks

• Computer Networking is the linking of two or more computing devices together for the purpose of sharing data, communicating, software and peripherals
• Local Area Networks/LAN- self contained within a single building or group of buildingd (for example: A School environemnt)
• Wide Area Networks/WAN- covers a much wider area even worldwide, such as all the offices of a large corporation
• Metropolitan Area network/MAN- Covers large Areas (for example: City)

Disadvantages

• Lack of access
• Technical Knowledge needed
• Cost

Advantages

• Improved communication
• Sharing of resources (Intranets and Extranets)
• Central maintenance and support

Intranet

• This is like a `private internet` for an organisation to communicate within itself, therefore not accesible to the outside world. The intranet is a network of computers that allow sharing of information in a user-friendly fashion

Extranet

• This is a collection of a number of intranets and is spread over the whole company witht he intranets being the branches, for example. An extranet allows a user access to the other intranets it contains as well as the Internet. This allows for communication within and outside the company

Characteristics of a network

Peer to Peer

• When there are mmore than two computers, the hub provides the connectivity
• A peer to peer network could just be twi computers linked together that can share resources, e.g. a printer
• Commonly used in homes

Client Server

• The server has a specialised network operating system to control user rights and to store individual user files
• Client server networks allow centralised control over security and backup
• A client server network uses a server to control it

Examples of Network Topologies

Star Network - Each node in a star network is connected to a central computer that controls the network.

Advantages

• If one cable fails, the other stations are not affected
• Consistent persomance even when the network is being heavily used

Disadvantages

• May be costly to install because of the length of cable required
• Reliance on central host

Bus Network - All devices share a single cable, information can be transmitted in either direction from any PC to another.

Advantages

• Easy and inexpensive to install
• Easy to add more stations

Disadvantages

• The whole network goes down if the main cable…