on Wednesday, August 1, 2012

NetWork Topology
Star Topology
            In a star network all computers and other communications devices are connected to a central point such as a hub, file server or a host computer.

Ring Topology
                 In a Ring network all communications devices are connected in a continuous ring. Messages are passed around the ring until they reach the right destination.

Bus Topology
               In a bus network communications devices are connected to a common channel. There is no central computer and the communications devices transmit messages to the other devices.
Mesh Topology

 







Networks

Network
                 A network is a collection of entities that exchange information or goods.A few examples of networks are railway system, nervous system of animals, telephone system.

Computer Network
               A network consists of two or more computers that are linked in order to share resources (such as printers and CD-ROMs),exchange files, or allow electronic communication.The computers on a network may be linked through cables, telephone lines, radio waves, satellites, or infrared light beams.
            A communications network is a system of interconnected computers, and communication devices that can communicate with one another and share resoureces. At the most elementary level, a computer network consists of two computers connected with each other by a cable to allow them to share data.A device connected to a network is called a node.A node may be a device such as a computer, a printer, workstation etc.

Local Area Network (LAN) - 
                   LANs are networks usually confined to a geographic area, such as a single building or a college campus. LANs can be small, linking as few as three computers, but often link hundreds of computers.





Metropolitan Area Network (MAN) –
                  MAN is basically a bigger version of a LAN and normally uses similar technology. It might cover a group of near by corporate offices or a city and might be either private or public.


Wide Area Network (WAN) –
                 Often a network is located in multiple physical places. Wide area networking combines multiple LANs that are geographically separate. This is accomplished by connecting the different LANs using services such as dedicated leased phone lines, dial-up phone lines (both synchronous and asynchronous), satellite links, and data packet carrier services.