Topology refers to the layout of connected devices.
The choice of topology is dependent upon
• type and number of equipment being used
• planned applications and rate of data transfers
• required response times
Network topologies are categorized into the following basic types:
Bus networks use a common backbone to connect all devices. A single cable, the backbone, functions as a shared communication medium that devices attach or tap into with an interface connector. A device wanting to communicate with another device on the network sends a broadcast message onto the wire that all other devices see, but only the intended recipient actually accepts and processes the message. Both ends of the network must be terminated with a terminator. Wiring is normally done point to point. A faulty cable or workstation will take the entire LAN down. A faulty cable or workstation will take the entire LAN down.
Fig Bus Network Topology
In a ring network, every device has exactly two neighbors for communication purposes. All messages travel through a ring in the same direction (either "clockwise" or "counterclockwise"). A failure in any cable or device breaks the loop and can take down the entire network.
To implement a ring network, one typically uses FDDI, SONET, or Token Ring technology. Ring topologies are found in some office buildings or school campuses.
A data token is used to grant permission for each computer to communicate.
Fig Ring Network Topology
Many home networks use the star topology. A star network features a central connection point called a "hub" that may be a hub, switch or router. Devices typically connect to the hub with Unshielded Twisted Pair (UTP) Ethernet.
Compared to the bus topology, a star network generally requires more cable, but a failure in any star network cable will only take down...