Foreign Related Study Star Topology

Star Topology

http://networking-communications.knoji.com/star-topology/

In star topology, multiple devices are connected to a central connection point known as hub or switch. Devices are attached to the hub by using either copper cables or fiber optic cables. Star networks provide a cost-effective method for sharing information between different users. Star topology can be used in airline reservation counters and small business offices where employees want an access to common applications and files.

Basic Structure of Star Topology

Each device is connected point-to-point to a central device which is either a hub or switch. Hub manages and controls all the functions of the network. It also acts as a multi port repeater for the data flow. Hub is used to connect segments of LAN and contains multiple ports. Hubs can be passive or active. Passive hubs are used as a connection point which routes all the traffic towards the devices. It does not amplify or regenerate the signals.

They amply take all of the packets they receive on a single port and broadcast them across all ports. Active hub contains electronic circuits that regenerate and retransmit the information. Active hubs actually do somethirng other than simply rebroadcast data. Generally, they have all of the features of passive hubs, with the added feature of actually watching the data being sent out. Active hubs take a larger role in Ethernet communications by implementing a technology called store and forward where the hubs actually look at the data they are transmitting before sending it. Also it repairs certain "damaged" packets.

Data is passed through the hub before reaching the destination. For example, device A wants to transmit data to device B. Device A first sends data to the hub. If the hub is passive, it rebroadcasts the data to all the devices in star network, including the device A. Each device has to read the address specified in data to determine if the data is intended for that device....