Network topologies

Network topologies

In this blog I will be explaining the five different network topologies. I will add in a diagram, explaining the uses and talking about the limitations. The five different topologies are Star, Mesh, Bus, Tree and Ring.

Star

A star network has its own cable for each device. These cables are normally connected to a switch or a hub. The hub sends all the packets of data to all of the different devices. If a switch was used, it would only send packets of data to the device that needs it. Figure one shows how the star topology works. The information is sent out to the devices. A benefit of the star network is that it is very reliable. If one of the cables or device fails then all of the other devices can still work. Also no data collisions can happen with the data being sent around. A limitation of the star network is that is expensive to install. There is many cables used for this and the cables do cost quite a bit of money. Another limitation would be if the hub went down, the whole system would go down and no one would have a connection to the network.

Figure one: An example of the star network.

Mesh

The mesh topology is a network where each device is connected to each other. This network is normally used for wireless networks as everything is connection. As you see in figure two, everything is connected to everything else. A benefit of mesh would be if one device in the network goes down it can still function properly. This is good if there are many networks in the service. If one of the devices went down, the other people would not get affected. A limitation of the mesh topology would be is that it is very expensive to set up and maintain. This would not be a good choice for a company because it would cost a lot to maintain.

Figure two: An example of the mesh network.

Bus

A bus network works by having all of the devices connects via one cable. Each end of the cable there is a terminator installed. This is to stop the signals reflecting back down the cable. Figure three shows how a bus network works. As you can see all of the devices are connected up to the one cable. A benefit to the bus topology is that is easy to install. If you do not have a lot of money or you want to set up a simple network you could easily set up the bus network. Another benefit for the bus topology is that it is cheap to install. If your business was on a budget you could install the bus network to save money. You need less cable to install so it is cheaper. One limitation to the bus network is that if the cable fails the whole network goes down. If the cable got damaged you would have to get it repaired and then the network would work again. Another limitation would if there were too many people on the network. The more people you have on there, there would be more data collisions. For example, if you have 100 people on the network, there would be many data collisions.

Figure three: An example of the bus network.

Tree

The tree topology is like the star topology and the tree topology. As you can see in figure four, there is a bus topology with two star topologies connected to it. If the main cable failed between the two star topologies, they would not be able to communicate with each other. A benefit of a tree topology is that expansion of the network is easy to do. If you were expanding your company you could easily make it bigger and add on another star topology. Another benefit of the tree topology is that error detection and correction is easy to do. This is good if you have errors in your network or with packets of data being sent around. A limitation of the tree topology is that it relies on the main bus cable. If that cable goes down the whole network could be broken.

Figure four: An example of the tree network.

Ring

In the ring network all of the different devices connected are connected to two other devices. This creates a ring for the data to travel around. All the data that gets sent around in one direction and each device receives each packet. Figure five shows how the ring network works. As you can see all of the devices that are connected in a ring and the data would get passed round. A benefit of the ring system is that the data can be transferred around quickly. This is good because if someone wanted some data in the network, it would not take too long to get there. A limitation would be if there was one problem with the ring the whole server would go down. This would be a problem if you wanted to send some important information to someone then the server goes down.

Figure five: An example of the ring network.

  

References

BBC (2015) Star network topology [Online] Available at: http://www.bbc.co.uk/schools/gcsebitesize/ict/datacomm/networktopsrev3.shtml [Accessed on 20/01/15]

BBC (2015) Ring network topology [Online] Available at: http://www.bbc.co.uk/schools/gcsebitesize/ict/datacomm/networktopsrev2.shtml [Accessed on 20/01/15]

BBC (2015) Bus network topology [Online] Available at: http://www.bbc.co.uk/schools/gcsebitesize/ict/datacomm/networktopsrev1.shtml [Accessed on 20/01/15]

Computer Hope (2015) Tree network topology [Online] Available at: http://www.computerhope.com/jargon/t/treetopo.htm [Accessed on 22/01/15]

Computer Hope (2015) Mesh network topology [Online] Available at: http://www.computerhope.com/jargon/m/mesh.htm [Accessed on 22/01/15]

Images

Figure one: BBC (2015) Star network topology diagram [Online] Available at: http://www.bbc.co.uk/staticarchive/babaaeda24aa3798f67ae3548e58bd94e306f661.gif [Accessed on 20/01/15]

Figure two: Tutorials point (2015) Mesh network topology diagram [Online] Available at: http://www.tutorialspoint.com/data_communication_computer_network/images/mesh_topology.jpg [Accessed on 22/01/15]

Figure three: BBC (2015) Bus network topology diagram [Online] Available at: http://www.bbc.co.uk/staticarchive/9933e41867b45fa9319fa74db5ac7f33b71d44c8.gif [Accessed on 20/01/15]

Figure four: Webopedia (2015) Tree topology diagram [Online] Available at: http://www.webopedia.com/imagesvr_ce/6353/tree_topology.gif [Accessed on 22/01/15]

Figure five: BBC (2015) Ring network topology diagram [Online] Available at: http://www.bbc.co.uk/staticarchive/a5ed94c8c3d50b8e5f859dc5601d4d6a489a64b5.gif [Accessed on 20/01/15]