The Hierarchical Star Topology consists of all the computers in a specific network being connected to a single main point, like a server or hub, which in turn, would be located in an equipment room or centralize location. With the Star topology, hubs are used to facilitate the topology. The drawback to this is, there is about a 20%- 30% waste in unused ports and a company is paying for more ports that is can or will use. Another drawback to this topology is the entire network is reliant on the hub. If it were to fail, the entire network becomes inoperable. In addition to that, there is also potentially a problem if one of the workstations goes down. It can cause interference in the Star topology and cause the entire network to fail. The Star topology, in its basic design, doesn't account for redundancy or diversity, which can make this design very dangerous for business applications. Some of the advantages of the Star topology is it gives a much better signal because all the information isn't shared to every device. You can also add and subtract new devices to the network by simply plugging into or unplugging a device from the hub and monitoring the network is simplified because everything is centralized. The Bus Topology is the simplest network topology. Ethernet is an common example of Bus topology. Once a main network line is laid, all peripherals on the network talk on the same line and listen for each other's communication. One drawback to this topology is at each end of the network cable, there must be a terminator to absorb the signal and keep it from creating excess noise. Furthermore, if there is ever any form of cut or disturbance in the network line, the entire network fails. Coaxial cable was generally used when installing Bus topology. It was referred to as thin-net and was not the easiest product to work with. The more devices you add to this network, the efficiency of the signal goes down. Advantages of the Bus topology is it is very inexpensive to install and very easy to install and extend, if need be. Compared to other topologies, it too uses a lot less materials for a basic install. The Ring Topology is laid out in a continuous circle. There is no end or hub used when using this topology. Each computer, one at a time, receives a "token" to transmit data and when it is done, it then passes the token to the next device in the circle till it makes it back to the first device. This topology is very difficult to install and because of its circular design, makes adding new devices rather difficult. If any of the devices goes down, like other topologies I discussed, it too will affect the network and cause it not to function. In addition, network cards designed to run a ring topology, are very expensive. The advantages of the ring topology are few. Even with a large load of data on the network, the performance is not affected like it would on a bus topology. Adding a device, does not affect the networks performance and finally, each device, has equal access to any and all resources on the network.

Works Cited
Woodward, A. O. (2012). Cabling: The Complete guide to copper and fiber-optic networking. Wiley Custom Learning Solutions. www.ianswer4u.com. (n.d.). Retrieved from http://www.ianswer4u.com/2011/05/star-topology-advantages-and.html#axzz2HWdI928e