Network

Other topologies

Star bus topology

The Sta bus is the combination of the bus and star topology. In a star bus topology, there are several star

Topology networks linked together with linear bus trunks. If one computer develops a fault, it will not affect the rest of network, If a hub develops a fault, All computers on that hub will be disabled.

        Hub                                   Hub                               Hub

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Figure1.7 Star Bus network

Star ring Topology

The star ring is a combination of ring and topologies. The hubs in a star are connected in a star pattern by the main hub.

Access Methods

The set of rules defining how a computer puts data onto the network cable and retrieves data from the cable.

Is called an access method. Access methods prevent simultaneous access to the cable by ensuring that only one computer can put the data on the network cable methods keep the transmission of network data orderly process.

The three main access methods are:

    • Carrier- Sense Multiple Access.

    •   With Collision Detection

    • With Collision Avoidance

    • Token Passing

    • Demand Priority

Carrier-sense Multiple Access with Collision detection

In the Carrier-sense Multiple Access with Collision Detection (CSMA/CD) Method. Each computer on the network senses any single passing on the cable.   The computer can only transmit if the cable is free. If two or more computer sends data at exactly the same time. It will result in data collision. When a collision occurs, the two computers involved stop transmitting and then attempt to re-transmit after a certain period of time. The collision...