Network Topologies
The physical or logical layout of a network.
Star Topology
All devices connect directly to a central node (usually a switch or hub).
Advantages
- Resilient: An isolated failure (one broken cable) does not take down the whole network; only that device loses connection.
- Scalable: Very easy to add new devices without disrupting the network.
- Performance: Because each device has its own dedicated connection to the switch, there are fewer data collisions.
Mesh Topology
Devices are connected to multiple other devices, providing redundant pathways.
Advantages
- Extreme Reliability: If one node or connection physically breaks, data simply routes around the broken path.
- No Central Point of Failure: There is no single central switch that can take down the whole network if it breaks.
- Extended Range: Nodes can act as repeaters to push the signal further (e.g. smart home mesh Wi-Fi).
Examiner's Eye
When explicitly asked for a disadvantage of the Star Topology, you must use the precise phrase "central point of failure". While a broken cable only affects one PC, if the central central switch itself loses power or drops, the entire network fails instantly.
Check Your Understanding
1. You are managing a Star Topology. One of the Ethernet cables connecting a user's laptop to the switch is cleanly severed by a closing door. What happens to the network?
2. What is the single biggest disadvantage and vulnerability of a Star Topology?
3. Why might an organisation intentionally choose a full Mesh Topology despite it being significantly more expensive to cable than a Star Topology?
Stretch & Challenge (AO2 Application)
Written Exam Scenario (AO2/AO3)
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