In the world of telecommunication systems various set ups that can optimize the efficiency and productivity of a company’s network and operating system; these setups are called topologies. For the purposes of this discussion, the author will cover the following types of topologies and the advantages and disadvantages of each; these are mesh, bus, ring, and star topologies. The differences in Ethernet, Token Ring, and FDDI and wireless will be addressed. Another topic that will be covered is what level of the OSI model does the Transmission Control Protocol/Internet Protocol (TCP/IP) function.
Hopefully, at the end of this discussion the reader will have a better insight into the benefits that the proper topology can have on a corporation’s network.
Mesh – A mesh topology network allows for extreme redundancy and reliability. This type of topology connects all the computers in the network to each other with individual cabling. This way if one cable falters the others can pick up the traffic of the down cable without making the network hiccup.
The main advantages to having a mesh topology are the reliability factor and the independence that it affords the PCs to operate within the network. However, the big disadvantage of the mesh network is the cost and time to install the network because of all the wiring involved.
Bus – Bus topology, (aka – linear bus) is the most elementary and common method of networking computers. It allows for the computers to be connected to the network on a single cable called a trunk or backbone. Some of the advantages to having a bus network are the ease of installation and future upgrades to the network. This setup works best in an environment where the network is small and high bandwidths are not required. The use of a single cable keeps the cost of this topology extremely low. The disadvantages to this topology are that if a problem with the one wire the whole network is halted. As more equipment is added to the network performance is diminished as this network is slower than the other topologies to begin with.
Ring – A ring topology connects PCs on one cable that is circular and no terminated ends as the bus topology. The process in which data is transferred around the ring is called token passing and only one token in a network. The token travels to each PC in the ring until it finds one with information to transmit. The advantages to this type of network are that all the PCs have access to the network to send and receive data. Ring topology also allows for future growth of the network and can handle a heavy work load. The disadvantages are if one PC goes down the whole network will too and any revisions to the network can affect the network as well.
Star – Star topology employees the use of a hub to send information from a PC to the rest of the network. This setup is reminiscent of the IBM days when most PCs were hooked up to a centralized mainframe computer. The hub acts as a conduit for sending and receiving signals from individual PCs. Some of the advantages that a star topology offers are centralized resources and management along with better performance because the passing of data packets and device communication is more efficient. Whereas, the disadvantages are that the entire system is dependent upon the centralized hub and the size and performance of the network is directly related to the hub’s functionality. Lastly, the installation of this type of network is labor intensive.
Ethernet – The Ethernet is a local area network protocol that defines and manifests its specifications in the bottom two layers of the OSI model. Ethernet uses a bus or star topology and can handle speeds of up to 1000 Mbps. The Ethernet was also the catalyst for which the IEEE 802.3 standard was built on. Some of the advantages that the Ethernet has to offer are the design is easy to implement because the cabling is put together with T adapters and not other physical devices are needed and the cost is economical. Along with that because of the design of the cabling noise reduction is optimal. Some of the Ethernet’s disadvantages are reconfiguration is complex, and the setup is fault resistant. If an issues should arise within the Ethernet is problem can be hard to isolate and some of the cabling needed for the network is extremely specific.
Token Ring – A Token Ring network is connected in a circle however; the actual nodes are attached to a centralized component called a media access unit in a star topology. The creation of a token begins once a node initially logs into the network and travels continuously in the same directions looking to gather data from other nodes in the network. In comparison to the Ethernet, a Token Ring network is more costly and intricate however; Token Ring is far more dependable. Some of the advantages to the Token Ring network are if a part of the network goes down that part is isolated and does not affect the rest of the network and the PCs have the same time on the network. On the other hand, the installation is expensive because of the cabling and hookups.
FIDDI – A Fiber Distributed Data Interface (FIDDI) network is another version of a ring network. The network similar to a Token Ring network; minus the hub. FIDDI frequently employed as a backbone network meaning that it attaches to other networks and utilizes a more robust token passing method. The main advantage to the FIDDI network is that it has two directional rotating rings to ensure uninterrupted communications on the network. If for some reason the main ring is shut down then the auxiliary ring takes over and changes data direction until the main ring was back up and running. The disadvantage is most time the cost for this network setup is extremely high.
Wireless – The main advantages of having a wireless network are the unlimited mobility it gives its users and complete absence of cabling. In addition, the cost to set up a wireless network is extremely low because not a great deal of physical devices is needed. The installation is relatively pain free because one does not have to plan around components and a feature call application transparency allows software on a wired network automatically to function in a wireless environment. In contrast, the disadvantages are the network is highly vulnerable on a continuous basis; data transfer is directly dependent on the signal strength; and the available bandwidth is limited.
Levels of the OSI model TCP/IP functions in – The Transmission Control Protocol/Internet Protocol is an Internet protocol. TCP/IP can also be used in private networks. This protocol has two layers – the TPC breaks down data into smaller packets – and the IP makes sure the packet is routed to the correct destination. – TCP – is used in the Transport layer of the OSI model to allow source and destination host to converse by breaking down information into smaller packets then sending them over the Internet. – IP – used in the Network layer of the OSI model to make sure the IP are going where intended and where official packet format is define.
In conclusion, as one can see several options available for setting up a network based up on the needs and nature of a company’s business. With expert analysis and planning and implementation, the chosen network design can heap plenty of rewards and increase a company’s bottom line exponentially.