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NETWORKINGBSIT 4 / CHS TTH 12:30 2 / 202#NETWORKA collection of computing devices that are connected in various ways in order to communicate and share resources

Consist of 2 or more nodes that are linked via various methods to enable communication

#2NODE / HOSTrefers to any device on a network

DATA TRANSFER RATEThe speed with which data is moved from one place on a network to another key issue in computer networks#SOURCErefers to a node in a network which sends messagea.k.a SENDER or TRANSMITTER

RECEIVERrefers to the node that receives the messagea.k.a DESTINATION#A path where communication signals passes or goes through to reach is destinationChannels can be via physical means (i.e. cables, wires, etc.) or using wireless technology (infrared, microwave, satellites).

Any communications channel has a direction associated with itCommunications Channels#Communications ChannelsTransmitterReceiverSimplex ChannelCHANNEL TYPESTransmitterReceiverReceiverTransmitterHalf-Duplex ChannelTransmitterReceiverReceiverTransmitterFull-Duplex Channel#SimplexA channel whose direction of transmission is unchanging

For example, a radio station is a simplex channel because it always transmits the signal to its listeners and never allows them to transmit back.

#Half-Duplex single physical channel in which the direction may be reversed. Messages may flow in two directions, but never at the same time, in a half-duplex system. In a telephone call, one party speaks while the other listens. After a pause, the other party speaks and the first party listens. Speaking simultaneously results in garbled sound that cannot be understood.

#Full Duplex allows simultaneous message exchange in both directions. It really consists of two simplex channels, a forward channel and a reverse channel, linking the same points. The transmission rate of the reverse channel may be slower if it is used only for flow control of the forward channel.

#Any questions?End of Lecture.#