1.3

• Share files • Share peripherals • Access files from any computer on the network • Servers control security, software updates and data backup • Communication with others

• Covers a small geographical area • Hardware owned by organisation using it • Wired with UTP cable, fibre optic or wireless with Wi-Fi

• Covers a larger geographical area • Infrastructure between LANs leased from telecommunication companies who own and manage it • Connected with telephone lines, fibre optic cables, satellite links

• Increased security risks to data • Malware and viruses are able to spread very easily • If server fails, computers connected to it may not work • Computer may run slowly due lots of data travelling on the network

• Bandwidth • Number of users • Type of transmission media used • Error rate • Latency • Interference

• Causes network to slow down if there is insufficient bandwidth for the data

• Amount of data that can be sent and received successfully in a given time • Measured in bits per second

• Wired bandwidth > wireless • Fibre optic cables bandwidth > copper cable • Due to less interference

• Signals are slowed down due to other factors • e.g. physical factors: a wall • e.g. the interaction of signals from different devices • e.g. appliances such as microwaves may emit signals that interfere with signals sent out by routers

• Number of errors that occur while data is transferred • The higher the error rate, the more frequent data must be resent before arriving correctly

• Wireless: range, environmental factors • Wired: grade of material, length of cable

• Delay from transmitting data to receiving it • Caused by bottlenecks in the network infrastructure (e.g. hardware operates at different speeds thus unable to direct traffic effectively)

• Controls access and security to a shared file store • Manages Internet access • Manages printing jobs • Provides email services • Runs data backup

• Makes requests to the server for data

• All peers are equal • Serve their own files to each other • Usually have own printers • Responsible for own security and backup

• A single computing device not connected to any other device on a network

• Easier to manage security • Easier to backup all shared data • Easier to install software updates to all computers

• Expensive to set up and maintain • Requires IT specialists • Server is a single point of failure • Users lose access if server fails

• Easy to maintain • No special staff required • Not dependent on a single computer • Cheaper • No expensive hardware required

• Less secure • Need to manage own backups • Difficult to maintain well ordered file store

• A hardware component that allows a device to connect to a wired/wireless network • Has a unique MAC address that allows it to be identified on a LAN

• Allows wireless-enabled devices to connect to the network without cables • Convenient • Less bandwidth than wired • Security is a concern

• Sends data between computers on a LAN • Uses MAC address to send data to its destination device • Segments the network by forwarding traffic to the correct device

• Hardware used to connect networks • Sends data between networks • A LAN is required to network a WAN • Uses IP addresses on a device to route traffic to other routers