Network Topology

The term “topology” in networking refers to the configuration of cables, computers, and peripherals. The six common used topologies in networking are: bus, star, ring, mesh, tree, and hybrid. The three major topologies that I will be discussing further in detail are: bus, star, and ring topology. Bus topology is probably considered the easiest of the network topologies. In a bus topology, the devices are connected to a central cable called the bus. The bus cable carries the transmitted message along the cable. When the message arrives at each workstation, the computer checks the destination address contained in the message to see if it matches its own. If it matches the address, the message is transmitted along the cable and is visible to all computers connected to that cable. Bus topologies are easy to implement, and low cost. However, there are some disadvantages to this method. There are limits on cable lengths, and the amount of workstations that can be hooked up. The speed of the network is affected with the increase of workstations. If a cable fails it affects all workstations, and it can be difficult to locate which cable failed. Star topology is the most commonly used topology used in the computer networking world. They can be implemented in homes, offices, or buildings. All the devices are connected to a hub or switch. A hub is a specialized type of hardware that receives data transmissions and routes them to the proper destination. Star topologies are easy to install, easy to diagnose problems, and it is a centralized network. If the hub fails then the network will ultimately shutdown, uses a significant amount of cable, and hubs are more expensive. In ring topologies every computer or device has two adjacent neighbors for communication which creates a ring. All messages travel through the ring in the same direction (clockwise or counterclockwise). A station which wants to transmit waits for the token to arrive. A token is a short message that is circulated around the ring; it is passed from station to station. The message is originated from the controller or master station which inserts it onto the ring. When the token arrives, the station changes it from a token to a connector message, and adds its message. There are many advantages to having a star topology. The first being when there is a cable failure it only affects limited users because the administrator can route data around the failing node. Another advantage is that with the increase of workstations performance only diminishes slightly. However, the connections can be difficult to install, and they are also fairly expensive