1.3.3 Networks

The name given to two or more computers connected together with the ability to transmit data between each other.

-spread over a small geographical area or single site

-spread over a large geographical area

All the terminals (devices) are connected to a backbone cable, the ends of which are plugged into a terminator

• relatively inexpensive to set up - doesn’t require any additional hardware

• if backbone cable fails, the entire network gets disconnected as traffic increases, performance decreases • all computers can see the data transmission

Uses a central node, often a switch, to direct data through the network. Every device on the network is connected to the switch

• performance is consistent even with heavy network traffic • if one cable fails, only that station is affected • easy to add new stations

• expensive due to switch and cabling - if the central switch fails the rest of the network fails

every node is connected to every other node. Mesh topologies are most commonly found with wireless technology such as Wi-fi

• if using a wireless network, there is no cabling cost • as the number of nodes increases, the reliability and speed of the network gets better • nodes are automatically incorporated • nodes don’t go through a central switch, improving speed

• if using a wireless network, devices with wireless capability (which increases cost) must be purchased • if using a wired network, a large quantity of cable is required compared to other topologies like bus and star • maintaining the network is difficult

is a set of rules defining how two computers communicate with each other. Protocols are standard so that all devices have a designated method of communicating with each other, regardless of manufacturer

Hyper Text Transfer Protocol - used for page rendering

used for the transmission of files over networks

A stack of networking protocols that work together passing packets during communication.

A network of networks which allows computers on opposite sides of the globe to communicate with each other.

• specifies the protocol that needs to be used. I.e. if application is a web browser then it would select the HTTPS protocol

• establishes an end-to-end connection between the source and the recipient computer • it splits data up into packets with their packet numbers

• Adds the source and destination IP addresses - Routers use the IP addresses and sockets to forward the packets to the specified destination

Adds the MAC address identifying the Network Interface Cards of the source and destination computers

Used to name and organise internet resources. Domain names are much easier to remember than IP addresses, making it easier for users to quickly search for web pages

Segments of data.

• sender and recipients IP addresses • protocol being used • order of the packets • time to live ( tells packet when to expire so is not travelling forever)