LAN design question: which physical topology typically provides the greatest flexibility for adding, moving, or replacing devices and cabling in practice?
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ABus networks
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BRing networks
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CStar networks
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DCircuit-switched (T-switched) networks
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ENone of the above
Answer
Correct Answer: Star networks
Explanation
Introduction: Physical topology affects how easy it is to expand or reconfigure a local area network. Flexibility means minimal disruption when adding or relocating devices, straightforward troubleshooting, and limited impact from a single link failure. This question asks which topology generally offers the best flexibility for wiring changes in modern LANs.
Given Data / Assumptions:
- Focus is on physical cabling and ease of change management.
- Common topologies considered: bus, ring, and star.
- Assume typical Ethernet implementations (e.g., twisted-pair to a switch).
Concept / Approach: In a star topology, each device connects via a dedicated cable to a central hub/switch. Adding or moving a device usually involves terminating a new cable at the patch panel and switch—no interruption to other links. In a bus topology (thin coax), inserting a new node requires cutting into the shared cable and carefully maintaining impedance/terminations, risking downtime for the entire segment. In a ring, breaking the ring impacts all nodes unless special MAUs or protections are used. Thus, star provides the greatest practical flexibility and fault isolation.
Step-by-Step Solution:
Compare per-node cabling: star uses independent home runs; bus/ring share a path.Assess change impact: star changes affect only the link being worked on.Assess fault isolation: star localizes failures to a single port/cable.Select star networks as the most flexible topology.Verification / Alternative check: Modern enterprise and home Ethernet overwhelmingly use a star (switched) topology; structured cabling standards are built around this model, confirming its flexibility and maintainability.
Why Other Options Are Wrong:
- Bus: difficult expansions; a single fault can drop the whole segment.
- Ring: link changes interrupt the loop; specialized hardware needed for resilience.
- Circuit-switched (T-switched): describes WAN service type, not a LAN physical topology choice.
- None of the above: incorrect because star is correct.
Common Pitfalls: Assuming “fewer cables” equals “more flexible”; in practice, manageability and fault isolation dominate, favoring star.
Final Answer: Star networks.