Star Topology

In the star topology, all computers and other network devices connect to a central device called a hub or switch. Each connected device requires a single cable to be connected to the hub, creating a point-to-point connection between the device and the hub.

Using a separate cable to connect to the hub allows the network to be expanded without disruption to the network. A break in any single cable will not cause the entire network to fail. Figure 1.5 provides an example of a star topology.

Figure 1.5. Star topology.

The star topology is the most widely implemented network design in use today, but it is not without its shortcomings. Because all devices connect to a centralized hub, this creates a single point of failure for the network. If the hub fails, any device connected to it will not be able to access the network. Because of the number of cables required and the need for network devices, the cost of a star network is often higher than other topologies. Table 1.4 summarizes the advantages and disadvantages of the star topology.

Table 1.4. Advantages and Disadvantages of the Star Topology



Star networks are easily expanded without disruption to the network.

Requires more cable than most of the other topologies.

Cable failure affects only a single user.

A central connecting device allows for a single point of failure.

Easy to troubleshoot and isolate problems.

More difficult than other topologies to implement.