1.3.1 - Networks and Topologies

A group of interconnected computers or electronic devices for the purpose of communication.

They allow file sharing, hardware sharing, communication, levels of access, user monitoring, centralised security

Costly, susceptible to hacking, spread of malware and management requirements

Local Area Network

A network that is geographically confined to one building or site. It uses the builidng’s own infrastructure and cables to communicate Examples of LANs are small businesses, homes and schools

Wide Area Network

A network that is spread over a large geographical area. It can be spread across the country or even the world They use third party hardware and cabling to communicate e.g. satellites and the Internet

• Number of devices • Bandwidth • Number of transmission errors

The amount of data that can be transferred over a set amount of time. Businesses would have a higher bandwidth than homes as it has to be shared across more devices

The more devices on a network, the higher chance there is of collisions due to transmission errors. There are also more devices sharing the same bandwidth This means it will take longer to transfer a message or data. This reduces netowrk performance

Wireless access point

WAP creates its own wireless network, which devices connect to. This increases the range of the wireless network. The WAP then sends the wireless traffic it receives on to the main wired network.

Sends data by the fastest route between networks and uses an IP address to direct network traffic internally. Also sends local data to the internet

Network interface controllers/cards

A NIC provides a way of connecting to a network. It can either be built in such as in PC’s or it can be a wireless NIC such as in phones or tablets

Record which computers are connected to their corresponding ports. It then uses the mac addresses to send data to a specific device

They carry data signals from one computer to another. They are either wired cables such as copper and fibre optic or wireless such as Bluetooth

• Client server networks • Peer to peer networks

A server is able to manage and store files. They also control the network. A client doesn’t store any data or control the network and it relies on the server for data.

• Central storage of files - users can acces from any computer and single up to date versions of files - easier to keep track of files as they are edited • Central management (unlike peer to peer) which allows for central security, backups and software • Servers are dedicated machines left on all the time - data can always be accessed as it is never purposefully off

• Costly - both in hardware requirements and as specialist employees needed • Single server can only support a finite number of clients

• Limited consequences if a device fails - no central server • Cheaper hardware as servers are expensive • Easy to add new devices - no specialist set up or maintenance

File servers, web servers, mail servers

A collection of interconnected computer networks. It isn’t the same thing as the World Wide Web as this is only a service the Internet hosts