LAN:
In an industry,commercial organization or an office which has several computers in a building or a campus,need may arise to transmit data between computers.in such a situation a high-speed interconnecting network called local area network(LAN) is needed to interconnect the computers so that they can communicate with each other.There are various ways for interconnecting computers such as star,common-bus,ring type LAN,and so on.In a star type LAN there is a central controller that coordinates all communication between computers on the LAN.The common-bus type LAN also known as Ethernet,dose not have any central controller.Rather,the control of the bus is spread among all the computers connected to the common-bus.The common-bus is spread among all the computers connected to the common-bus.The common-bus is simply a wire usually a co-axial cable to which any number of computers can be easily connected.Any computer can take over the bus to transmit data.Two computers are not allowed to transmit data at the same time.Also,in the ring type LAN,the control is distributed among all of the computers on the network.A binary code called token is passed around the ring from workstation.All workstation are linked to form a continuous loop.A computer which wants to transmit data must possess the token.It takes the token form the bus,to prevent any other computer from transmitting.After the transmission is completed,it puts the token on the ring so that another computer which has to transmit data can receive it.
LANs are classified according to their data transfer speed,as:high speed,medium-speed and low-speed LANs. In high-speed lANs data are transmitted at the rate of 20 millon bits per second (MBps).such LANs are designed to link mainframe computers.In medium-speed LANs data are transmitted at the rate of 3-20 Mbps.such LANs are suitable to link smaller mainframes,minis and PCs.Example of a medium-speed LAN is Ethernet.Its speed is 10 Mbps.Low-speed LANs transmitted data at 3 Mbps.They are suitable to link PCs and other workstations.
WAN: when computers/terminals are spread over a wide area,they can e connected through public or private communication system.This type of network is called wide area network(WAN).Internet is also a kind of WAN.
In an industry,commercial organization or an office which has several computers in a building or a campus,need may arise to transmit data between computers.in such a situation a high-speed interconnecting network called local area network(LAN) is needed to interconnect the computers so that they can communicate with each other.There are various ways for interconnecting computers such as star,common-bus,ring type LAN,and so on.In a star type LAN there is a central controller that coordinates all communication between computers on the LAN.The common-bus type LAN also known as Ethernet,dose not have any central controller.Rather,the control of the bus is spread among all the computers connected to the common-bus.The common-bus is spread among all the computers connected to the common-bus.The common-bus is simply a wire usually a co-axial cable to which any number of computers can be easily connected.Any computer can take over the bus to transmit data.Two computers are not allowed to transmit data at the same time.Also,in the ring type LAN,the control is distributed among all of the computers on the network.A binary code called token is passed around the ring from workstation.All workstation are linked to form a continuous loop.A computer which wants to transmit data must possess the token.It takes the token form the bus,to prevent any other computer from transmitting.After the transmission is completed,it puts the token on the ring so that another computer which has to transmit data can receive it.
LANs are classified according to their data transfer speed,as:high speed,medium-speed and low-speed LANs. In high-speed lANs data are transmitted at the rate of 20 millon bits per second (MBps).such LANs are designed to link mainframe computers.In medium-speed LANs data are transmitted at the rate of 3-20 Mbps.such LANs are suitable to link smaller mainframes,minis and PCs.Example of a medium-speed LAN is Ethernet.Its speed is 10 Mbps.Low-speed LANs transmitted data at 3 Mbps.They are suitable to link PCs and other workstations.
WAN: when computers/terminals are spread over a wide area,they can e connected through public or private communication system.This type of network is called wide area network(WAN).Internet is also a kind of WAN.
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| example of LAN |
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