Networks

A computer that is not connected to a network

An arrangement(or group or setup) of two or more computers that are connected together for the purpose of sharing resources and/or data.

A network of physical objects that use sensors, actuators, embedded systems and wireless technology such as WiFi, Bluetooth and Zigbee, to collect and exchange data, with minimal or no human interaction.

Voice of Internet Protocol

Local Area Network Example: - School network

Wide Area Network Example: - Bank network

Wireless Local Area Network Example: - Hand held scanners

A computer connected to a network used to coordinate(store and share) vast amounts of data.

The time it takes for a message to transfer (ms). Also known as ping.

• An interconnected network or network of networks. • Most networks are part of the internet. • Consists of multiple cables or links that connect countries together, and can be though of as the backbone.

• Breaking down a large amount of data into small packets, each packet is independent of one another. • Each packet is tagged (has a header) with the recipient and source IP, checksum and a sequence number for the packets to be put back in order at the destination and checksum

A computer connected to a network used to coordinate(store and share) vast amounts of data.

A Network Topology is the arrangement with which computer systems or network devices are connected to each other.

In a bus topology, all nodes in the network are connected directly to a central cable that runs up and down the network. Advantages: - Cheap since little cabling needed - It still works if a node fails - Easy to add extra devices Disadvantages: - If the central cable is damaged the network stops working - More devices, slower since more collisions - All nodes can access all traffic can be security risk

In a ring topology network, each node is connected to two other devices.

In a star topology, all nodes indirectly connect to each other through one or more switches. The switch acts as a central point through which all communications are passed. Advantages: - Still works if a node fails - Damaged cable doesn’t stop the network from working - Data traffic only sent to intended recipient, secure - Easy to add extra nodes Disadvantages: - If central node fails, network stops working - Network capacity depends on central node’s capacity - Many cables, expensive and difficult to set up

In a mesh topology, there is no central connection point. Instead, each node is connected to at least one other node. Advantages: - Very fault tolerant, if a connection fails, message is re-routed - Nodes can be added/removed without having take network offline - Very scalable - Very high performance, each node is connected to many other nodes Disadvantages: - Many cables, difficult and expensive to set up

Manages communication on the network. Can have a built-in wireless access point (WAP).

• Transmission Control Protocol • Responsible for delivering data to a given address (packet switching) • Transport layer

Modulator/Demodulator

• Hyper Text Transfer Protocol • Application layer

• Simple Mail Transfer Protocol • Application layer

• Internet protocol • Responsible for obtaining the address to which data is sent. • Internet layer

• Layered protocol stack (Application layer, Transport layer, Internet layer, Link layer) • Collection of protocols • It sets how data should be formatted and transmitted across networks