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Networks and the effects of using them (Modems (Modulator (A computer'…
Networks and the effects of using them
Modems
Modem means 'modulator demodulator' and is a device that converts a computer's digital signal into an analogue signals for transmission over an existing telephone line.
Modulator
A computer's digital sign into an analogue signal for transmission over an existing telephone line.
Demodulator
To enable the computer to process the data
Dial-up modems operate at transmission speeds of about 60 kilobits.
Modern broadband or ADSL (asymmetric digital subscriber line) modems operate at up to 100 Megabits.
Hubs
Hubs are hardware devices that can have a number of devices or computers connected to them.
Its main task is to take any data packet received at one of its ports and broadcast it to every computer in the network.
They are often used to connect together a number of devices to form a LAN.
Switches
Switches are similar to hubs but are much more efficient in the way that they distribute data packets.
They connect a number of devices or computers together to form a LAN.
Each device or computer on a network has a media access control (MAC).
Bridge
Bridges are devices that connect one LAN to another LAN that uses the same protocol.
They are often used to connect together different parts of a LAN so that they can function as a single LAN.
Bridges tend to be used to interconnected LANs since sending out every data packet to all possible destinations would quickly flood larger networks with unnecessary traffic.
Router
Routers inspect the data packets sent to it from any computer on any of the networks connected to it.
Routers enable data packets to be routed between the different networks, for example, to join a LAN to a wide area network (WAN).
Since every computer on the same network has the same part of an internet protocol (IP) address, the router is able to send the data packet to the appropriate switch and it will then be delivered using the MAC destination address.