Royal Latin School

Describe, using diagrams or otherwise, the ring, bus and star network topologies Once you have decided to network a number of computers together, the next decision which needs to be made is which network layout or topology would be the best to use. There are a number of different topologies to choose from, the three most popular being bus, ring and star. You must be able to describe the differences between them, to identify the advantages and disadvantages of each and if possible, provide a drawing to illustrate your written points.

Bus Network

Bus Network Topology This is the simplest one to connect together. A single cable joins all of the workstations, printer, file server and other components together. At each end of the bus is a 'terminator'. This is a piece of hardware which prevents signals bouncing back and forth (echoes).

Adv. Vs Dis-adv. Advantages  Easy to install  Easy to add extra workstations  Uses less cable than a Star network  Best choice for temporary networks Disadvantages  If there is a problem with the central cable, the entire network stops working  If there are a lot of workstations on the network, data can travel slowly.  Data collisions can happen as the network becomes busy  Low security - every workstation can see all of the data in the network  Limited cable length and a maximum number of workstations

Ring Network

Ring Network Topology In a ring network layout, all of the computers are connected to one another in a circle. The data passes from one computer to the next one and then all the way around the ring layout until it reaches the destination computer. Advantages  Transmission of data is fairly simple as it only travels in one direction  No data collisions  Extra computers can be added easily with little effect on performance - although you have to shut down the network to be able to do this.

Ring - Disadvantages Disadvantages  If a single machine is switched off, the network doesn't work  If a cable breaks, the network doesn't work  Data must pass through every computer until it reaches its destination. This can make it slower than other network layouts.  If there are any problems with the network, they can be difficult to identify the cause.

Star Network

In a star network layout, each workstation is connected by its own cable directly to the server. Star networks are usually the layout of choice in schools and offices because they tend to be the most reliable of the topologies. Advantages  Star networks are very reliable. If one connection fails, it does not affect other users  Very few data collisions as each workstation has its own cable to the server  Good security - no workstation can interact with another without going through the server first Disadvantages  The most expensive network layout to install because of the amount of cables needed  Installing the network usually needs experts to set it up  Extra hardware such as hubs and switches may be needed  If the server crashes or stops working then nobody will be able to access their files or use the network.