Topologies

Topologies

1. Bus

   • The computer systems are connected to a single cable (bus)
   • Has terminator on each end to ensure that network functions correctly
   • How
     • The bus carries packets along the cable
     • The packets arrive at each computer system it checks the destination address contained
     • if the address does not match the computer system ignores the packet
     • The address of the computer system matchces that contained in the pack, it processes the data
   • Disadvantages
     • Difficult to troubleshoot the bus
     • limited cable length and number station
     • if there is a problem with the main cable or connection the whole network is down
     • low security
     • Data collisions are more likely, which causes the network to slow down
   • Advantages
     • Easy to implement and add more compute systems to the network
     • Quick to set up- well suited for temporary netwroks
     • Cost effective - cheap - less cabling

2. Ring

   • Packets are sent being passed from one computer system to the next until they arrive at their destination
   • Advantages
     • Data is quickly transferred withwout a bootle neck
     • the transmition of packets are simple is simple as packets travel in one direction
     • Nodes have little impact on bandwidth
   • Disadcantages
     • if a system fails the ring is broken
     • if the cable is broken the network goes down
     • difficult to troubleshoot
     • To add a node all other nodes must be shut down

3. Star

   • Each computer system is connected to a central node (hub)
   • Disadvantages
     • Expensive to install - more cabling required
     • Extra hardware required, such as a hub
   • Advantages
     • Good performance/fast
     • Easy to set up
     • possible to add more computer systems without taking the network down
     • any non centralised failure will have very little effect on the network
     • Good security
     • minimal network collisions