In a star topology, all computers are connected through one central device known as a hub or a switch, as illustrated in Figure 1. Each workstation has a cable that goes from the network card to the hub device. One of the major benefits of a star topology is that a break in the cable causes only the workstation that is connected to the cable to go down, not the entire network, as with a bus topology. Star topologies are very popular topologies in today’s networking environments.
Figure 1: Star Topology
ADVANTAGES OF A STAR TOPOLOGY:
One advantage of a star topology is scalability and ease of adding another system to the network. If you need to add another workstation to the network with a star topology, you simply connect that system to an unused port on the hub. Another benefit is the fact that if there is a break in the cable it affects only the system that is connected to that cable. Figure 1-7 shows a hub with a few ports available. Centralizing network components can make an administrator’s life much easier in the long run. Centralized management and monitoring of network traffic can be vital to network success. With a star configuration, it is also easy to add or change configurations because all of the connections come to a central point.
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| Figure 2: Hub |
DISADVANTAGES OF A STAR TOPOLOGY:
On the flip side, if the hub fails in a star topology, the entire network comes down, so we still have a central point of failure. But this is a much easier problem to troubleshoot than trying to find a cable break with a bus topology. Another disadvantage of a star topology is cost. To connect each workstation to the network, you will need to ensure that there is a hub with an available port, and you will need to ensure you have a cable to go from the workstation to the hub. Today, the cost is increasingly less of a disadvantage because of the low prices of devices such as hubs and switches.