Cambridge IGCSE Computer Science (0478) · lesson 10 of 35 · 25 min
What Is a Network Topology?
A network topology describes how devices (nodes) are physically or logically connected. The choice of topology affects performance, fault tolerance, cost, and ease of management.
Common Topologies
Star Topology — Most Common Today
Modern LANs almost always use a star topology with a central switch. Each device has its own dedicated cable to the switch. If one cable fails, only that device is affected. The switch learns which device is on each port and forwards frames only to the correct destination, reducing collisions and improving performance.
In a star topology, if the central switch fails:
- Only one device is affected
- The whole network goes down
- Half the devices are affected
- Nothing happens
- Answer: 1
All devices connect through the switch; if it fails, all lose connectivity.
Which topology is most fault tolerant?
- Bus
- Star
- Ring
- Mesh
Answer: Mesh
Mesh provides multiple paths between every pair of nodes.
Which topology uses a single shared backbone cable?
- Star
- Ring
- Bus
- Mesh
Answer: Bus
Bus topology uses one shared cable that all devices tap into.
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