Topology

Topology

1. BUS Network

   • Advantages
     • Cheap to operate for large numbers of computers, as less cable is used
     • The attachment of devices is straightforward and the cable can be extended, if necessary, to additional segments
   • Disadvantages
     • They are not the most reliable of networks
     • If there is a fault in the line then all of the machines go off

2. RING Network

   • Advantages
     • There is no dependence on a central computer as data transmission around the network is supposed by all of the devices in the ring
     • Very high transmission rates are possible
     • Routing between devices is relatively simple because messages normally travel in one direction only around the ring
     • The transmission facility is shared equally around the ring
   • Disadvantages
     • The system depends on the reliability of the whole ring and the repeaters- if one node breaks down, transmission between any of the devices in the ring is disrupted
     • It may be difficult to extend the length of the ring because the physical installation of any new cable must ensure that the ring topology is preserved

3. STAR Network

   • Advantages
     • Security is higher as no workstation can interact with any other without going through the central computer
     • Each spoke in the star is independent of the rest and a fault in the link will not affect the others
     • It is not easy to add new stations
     • The data transmission speeds used can vary from one link to another
     • Backup data can be done centrally
   • Disadvantages
     • The network is vulnerable to hub failures, which affects all users
     • For a LAN, the network may be costly to install because of the length of a cable needed
     • For a WAN, the control of communications in the network requires expensive technology

4. Client Server Network

   • Advantages
     • Speed of transfer as only part of the files need be spent by dedicated servers
     • All users work on the same piece of data
     • The running and maintenance is done by specialist, users don't need this knowledge
     • Security is centralised through user access and passwords, and files are stored centrally
     • Back-up of files are done for all files are done for all files regularly and centrally
   • Disadvantages
     • Entirely dependant on the server, the system is down if the server has a fault
     • A more costly system to run, with expensive equipment, needing a specialist network administrator
     • Software is more expensive as it is dedicated to network use.