When designing a network it is important to consider which topology is best suited to the user requirements. The topology is the construction or layout of the network. Cost of implementation is also an important factor as are the running costs. The question of what the consequences are should a system failure occur, whether it be just a part of the network or total system failure should also be cogitated.
The external communications requirements will also be investigated in this report. Whether a modem should be used or whether a faster system is needed depending on the amount of traffic that is forecast in and out of the company. The number of external connections required is also a ...view middle of the document...
The bus topology is not easy to administer or trouble shoot because there is no central point from which all PCs are connected on an equal basis. There is also a limit to the cable length and number of machines that can be connected. The performance of the network is compromised as more machines are added. If the cable is broken the whole network will fail.
A ring network is similar to a bus network as far as each PC is connected to another and data is read by each machine sequentially. Unlike the bus topology there is no server required as each PC handles its own applications and shares resources over the entire network. The ring topology gives each machine equal priority because there is no central point.
The advantage of such a topology is that each machine has equal chance of transmitting data. Another advantage is that there is minimal impact on performance as more machines are added.
The disadvantage of adding more machines to the network is that it can be difficult to add machines to the network because there is no central point from which to connect them. The ring has therefore got to be broken in order to achieve this. Another disadvantage is that if one machine goes down it could cause the whole network to fail.
The mesh topology is the most secure of all topologies. It is a variation of the bus topology except the machines are connected in a daisy chain fashion, as opposed to being connected sequentially along a single line. Each machine is also capable of transmitting, receiving and routing data as there is also a central point to which the machines are connected. The main advantage of this is that if a cable somewhere on the network is broken, the network will not completely fail.
The main disadvantage of this topology is the expense of the extra cabling required as opposed to the other topologies.
The star topology is emerging as the most common network layout for LANs (Local Area Networks). This is probably because it is the most flexible topology. It is very easy to add and remove machines from a network of this type without having very much effect on performance. There is a central server or switching hub from where all of the machines are connected.
One of the advantages of a star network is that a low specification twisted pair cable is all that is required for connection between the individual machines and the central hub. This is because data flow is relatively low between PC and hub. Unlike the other topologies, each PC has exclusive use of the cable that is used to connect it to the network. Another advantage of this layout is that a fault on one of the PCs will not affect the rest of the network. Maintenance of a topology of this type is also relatively inexpensive and not as problematic as other topologies.
This topology does have some disadvantages. A star network requires more cable than other topologies such as ring or bus. It can however be argued...