Network Technologies 📡

Bus network

computers are connected to a main cable known as the 'backbone' where data can travel along both directions

Advantages of a bus network

• Very easy to install, just needs attached to the backbone/ bus

• Cheaper than other topologies as less cabling, suitable for smaller networks

Disadvantages of a bus network

• If main cable fails or gets damaged, the whole network will fail

• As more workstations are connected, the performance and efficiency becomes slower

• Less secure than star as all traffic transmits through main cable, compromised if intercepted

Purpose of a terminator

to stop signals reflecting back down the bus, preventing data collisions

Star network

Computers are connected by their own cable to a file server

Advantages of a star network

• another computer can be added by attaching it’s cable to the file server

• if a cable breaks, only one computer fails

• Rarely slows down as no data collisions can occur

Disadvantages of a star network

• All data on the network must pass through the file server

• if the file server fails the entire network fails

• File servers are expensive

Other names for file server

central node, nexus or hub

Ring network

Each computer is directly connected to two other adjacent computers to form a ring and all data travels in one direction, visiting each computer

Advantages of a ring network

• transfer data quickly as there won't be any data collisions

• cheap as no need for file server

Disadvantages of a ring network

• To add a new computer the cable is disrupted and the entire network fails

• no central or controlling computer

• data has to visit every machine before intended destination

Network

Consists of a number of computers linked using a cable or wireless technology

LAN

Local Area Network spread over a small geographical area e.g a building

WAN

Wide Area Network spread over large geographical area on global scale requiring telecommunications to link and communicate

Advantages of networks

• Users can save their work on file server and retrieve it on any computer within the network

• Expensive hardware can be shared e.g printers

• Files on file server can be shared throughout the organisation

• Installing software and updates onto the file server allows all computers to access it quickly

Disadvantages of networks

• The set-up costs can be expensive as additional hardware has to be purchased

• A software virus can spread quickly across the network, affecting all users and data

• When a large number of users are logged on, access speeds can be slow

• Specialist staff is often required to maintain security and perforance

World Wide Web

an application that uses the internet

Internet

WAN of websites, each with their own unique address (URL)

What is the internet made up of?

Consists of web pages developed using a web authoring language such as HTML that need a communications protocol (HTTP) to access

Intranet

Similar to internet but is managed by an organisation and only authorised users, with a username/ password, can access

Internet of things IoT

The impact of the internet on how we live and work, any device that can communicate using Wi-Fi technology is included

Network interface card

electronic circuit board built into a computer with a port to allow a network cable to be attached

do all computers use network interface cards?

portable devices such as laptops are supplied with a standard wireless interface card (WNIC)

Need for network interface cards

allows it to be connected to a network and communicate with file server/ other computers

Network cables

generally made of copper and data travels along the cables to and from the file server

Need for network cables

physically connects a computer to a network

Switch (or switched hub)

connection point to organise communication between computers and file server, checking destination of data received and forwarding to intended computer

Need for switches

allows a large number of computers on a network to be connected and communicate with one another

Router

sophisticated switch hub acting as gateway between networks by either cable or wireless e.g LAN connected to internet

Need for routers

monitors traffic (data) as it passes through and finds the most appropriate route to its destination using IP addresses, can also limit access to sites

wifi

Wi-Fi connections use radio waves and a wireless router. Devices with built-in wireless adapters can connect to a network

advantages of wifi

no need for cabling

disadvantages of wifi

limited distance on how far the signal can travel and strength

bluetooth

Uses short-range wireless technology to connect two devices together

advantages of bluetooth

since the devices communicate directly there is no need to have a router

disadvantages of bluetooth

for devices to begin transferring data between each other they have to be synchronised or ‘paired’

optical fibre

bundle of glass strands, each carrying a data signal as pulses of light, so many can be sent at once

advantages of optical fibre

using glass means signals cannot be interfered making it very secure

disadvantages of optical fibre

it requires the use of repeaters for data to travel over large distances

4G

capable of high speed data access and high quality video streaming on a global scale

5G

5G is more reliable and has greater speeds

advantages of 4G/5G

fully supports wireless world wide web with little or no limitations

disadvantages of 4G/5G

it uses a lot of battery