A star network consists of one central switch, hub or concentrator , which acts as a conduit (pipe) to transmit messages. The hub and leaf nodes, and the transmission lines between them, form a graph with the topology of a star.
| Data on a star network passes through the hub, switch, or concentrator before continuing to its destination. The hub, switch, or concentrator manages and controls all functions of the network. This configuration is common with twisted pair cable. However, it can also be used with coaxial cable or optical fibre cable. |
Advantages
- Benefits from centralization / central control: Centralization allows the inspection of traffic,analysis of the traffic and detection of suspicious behavior. (and control through mechanisms like FIREWALL etc)
- Easy Isolation of devices: Each device is inherently isolated by the link that connects it to the hub. This makes the isolation of individual devices straightforward and amounts to disconnecting each device from the others. This isolation also prevents any non-centralized failure from affecting the network.(e.g. VIRUS infected device )
- More reliable: Fault detection and isolation of faulty node is easy. Each link or device can be probed individually.
- Simplicity/ simple protocols: This topology is easy to understand, establish, and navigate. There is no need of complex routing or message passing protocols.
- Easy to expand and manage (add new node)
Connecting additional devices to the hub or , increasing its capacity, increases the size of the network very easily.
- Better performance: star topology prevents the passing of data packets through an excessive number of nodes. Although this topology places a huge overhead on the central hub, with adequate capacity, the hub can handle very high utilization by one device without affecting others.
- No disruptions to the network when connecting or removing devices.
Disadvantages
- Long cable length required since each node connected all the way to central node
- Relatively expensive (long cable length , installation and maintenance , extra hardware – Hub / switch increase cost).
- Central Node dependency– High dependence of the system on the functioning of the central hub
Failure of the central hub renders the network inoperable
The performance and scalability of the network depends on the capabilities of the hub
- Network size is limited by the number of connections that can be made to the hub
Star Topology Conclusion A Star Network Topology is best suited for smaller networks and works efficiently when there is limited number of nodes. One has to ensure that the hub or the central node is always working and extra security features should be added to the hub because it is the heart of the network.
