Networks and the effects of using them
Internet Service Provider (ISP) a company that provides customers with access to the internet
Router
Routers are used to route data packets from one network to another network, based on IP addresses.
A router stores the addresses of all devices that are connected to it so that it can forward network traffic
to its destination using the quickest route.
Most routers used in homes include a switch and a wireless access point.
Home routers are dynamically allocated an IP address by the internet service provider (ISP).
When a data packet is received at one of its ports, the router inspects the IP address and determines
whether the data packet is meant for its own network or for another, external network. If the data
packet is meant for its own network, then the data packet is routed to the local switch or hub.
Otherwise, the data packet is transmitted to a different router.
network interface cards (NIC)
A network interface card (NIC) is needed to allow a device to connect to a network. An NIC turns binary
data into an electrical signal that allows access to a network. The NIC is usually integrated into the
motherboard on most modern computers
Switch
A switch connects devices on a network. It has ports, each of which can be connected to a device using a
cable.
unlike a hub, a switch stores the MAC addresses of all devices on the network. Each port on the switch
connected to a device will have a matching MAC address
The switch makes sure that data sent from any device gets to the correct device on the network. For
example, when printing a document, a laptop will send data that includes the printer's IP address to the
switch and the switch then sends the data to the connected printer.
Wi-fi
Wi-Fi is a wireless technology used to connect devices to a network. That network can itself then be
connected to the internet, so that devices connected to the Wi-Fi network can connect to the internet.
Wi-Fi is best suited to operating full-scale networks because it offers much faster data transfer rates,
better range and better security.
Bluetooth
Bluetooth is a type of wireless connectivity and devices need to be paired with each other before they
can communicate.
Bluetooth can be used to transfer small files between devices. It is used to connect devices such as
smartphones and laptops to peripherals such as portable speakers, headphones, earphones, keyboards
and mice.
Bluetooth is useful:
» when transferring data between two or more devices which are very close together (less than 30
metres distance)
» when the speed of data transmission is not critical
» for low-bandwidth applications (for example, when sending music files from a mobile phone to a
headset).