Network topologies are ways in which the elements of a network are mapped, physical and logical arrangements of network nodes (www.technopedia.com) . A node as defined by (compnetworking.about.com/od/itinformatontechnology/def_node) as any device connected to a computer network for example printers and cell phones . The three topologies that are going to being discussion are the bus topology, ring topology and the star topology. The bus topology consists of all the stations connected to a single cable with terminators at the end of each end. The cable is known as a trunk or back bone cable as shown in the diagram and it connects to every computer or workstation, printer and are all connected in one line. All the transmissions must pass through each device before reaching final destination.
Photo credits: www.bukisa.com/bus_topology_images.com
The terminal acts as a source for absorbing signals when they reach the end of the cable as it travel along the back bone cable. This means the bus topology does not have signal bounce, thus information is retained within the network. It is a preferable network topology because it has been found to be easy to connect to the different nodes because of its single line characteristic which makes setting up not complicated and easy to repair be there any fault found. As compared to other topologies like the star and the mesh system it requires less cable and is ideal to small networks that plan to stay small. In as much as it maybe ideal because it represents what most organization would want – cutting down costs or incurrence of few costs, it also can be a hindrance to flow of businesses. A failure of a device does not necessarily affect the others but the failure information does affect the whole system, thereby shutting it down. The inability of one device affecting other devices makes error detection hard because network is represented as flawless .It also recquires two terminals which need to fixed at each end of network and has a limited size because of the cable length this leads to a great disadvantage as to how many nodes can be connected on one bus. The ring topology is when a host machine is connected to two other computers and not more and the structure is in a circular like form. The flow of information flows in that same way. If information has to travel from one machine to another which is not directly connected to it, it still has to pass through all the other devices before reaching the final destination and in this case a new device can be added to the ring by adding a cable.
Photo credits: www.itiinfopoint.com
Although the ring system is not usually used by organizations the upside of it is that there is no central server that is needed since information exchanged between two nodes will still be communicated to the other entire nodes at the same time. Devices can be added because the ring topology can handle load unlike the bus network, at the same time devices can also be removed. The travelling of the data is high speed and it is less costly to set up compared to a star topology. Most organizations do not adapt to it because the failure of a node affects the whole network because one is connected to two other nodes which are also connected to a pair. This means there always have to be system check ups and repairs for all the nodes in the connection. There might not be a limit as to how many nodes are connected but as the number increases the slower the speed of the flow of information because the information still has to pass through all the nodes that are in the network, therefore it can be concluded that a change made either by adding or removing always affects the rest of the connected nodes. The last topology is the star topology which is in such arrangement that all nodes are individually connected to a central point for example a switch, and they are connected in a star-like setup the central being in the middle, (Dr. Dheeraj Sanghi, Computer Networks CS425). The hub is where the signals are transmitted and received. Organizations with the telephone system use this network system. This is the kind of topology I would recommend the organization to use.
Photo credits : http://www.buzzle.com/articles/advantages-and-disadvantages-of-different-network-topologies. Every device has a separate connection and information does not have to pass through all the connected devices to be finally received. This indicates the speed through which information is passed. Errors can be attended to early because they are detected easier because of the isolation of the different devices from each other, and save organization from incurring losses by prolonging repairing process. If the organization is a bank it will also be ideal because a failure of a devices does not affect the others therefore normal business activities can still continue. Businesses operating on a large scale are at an advantage. The addition and removal of other nodes can be done without having to switch off other devices like the ring topology network. Although the draw back on this kind of topology network is that it is dependent on the central hub and if that one fails the whole system of connected devices will shutdown, which could be an expensive event to an organization ,it still stands out from other network topologies as it combats the disadvantages associated with them.
Novell.com/primeir/prim02- Advantages of bus topology
Compnetworking.about.com/od/informationtechnology/def_node- definition of a node Computerhope.com/jargon/r/ringtopo/html- computerhope/dictionary/>R-definition Dr. Dheeraj Sanghi, computer networks (CS425) – star topology definition Wordpress.com.2010.02.04, Presentation on type of topology and networks by P.Agrawal,Reva Institute Of Technology And Management ,web page last updated May 19,2013 www.smallbusinesschron.com –Article by Andy Walton ,University of Leeds, advantages and disadvantages of different topologies www.buzzle.com – advantages and disadvantages of network topologies www.punarvasitechnologies.com – Goals for implementing computer networking in running of business business Management ,a Contemporary Compilation, First Edition - C.Nieuwenhuizen (ed),T.F.J Oosthuizen page 303- definition of business organization www.technopedia.com –definition/computernetworks.