Topologies

Topologies

1. Bus Topology

   • All devices are attached to a common connection medium, known as the backbone
   • Many devices can be attached to the backbone e.g. servers, printers or a router (if the computers need to connect to the internet)
   • At the end of the backbone is a terminator, which marks the end of the network
   • Advantages
     • Very cheap (very little cables needed)
     • Easy to add or remove computers
   • Disadvantages
     • Failure in the main cable will cause the failure of the network
     • The network can be significantly slowed by high network traffic

2. Star Topology

   • All devices are connected to a single central device e.g. a switch or a hub
   • Advantages
     • If one cable fails, only the device attached to it is isolated from the network
     • Faults are easy to find
     • It is easy to add extra devices
     • The system is secure, as data is only sent to devices that need the data
   • Disadvantages
     • very expensive (needs lots of cable)

3. Ring Topology

   • Each device is connected to two other devices
   • Advantages
     • No collisions, as there is typically only one batch of data allowed on the network
     • Very high rates of transmission are possible
   • Disadvantages
     • Failure of a single cable can bring down the entire network
     • Failure of a single device can bring down the entire network
     • Security is not ensures, as data passes through other devices en route to its final destination