Computer Networks · Class 12 · Network Topologies
networksrevision⏱️ 5 min read
Comparing Topologies
There is no best topology — only the best one for a job. Here are all five side by side, and a lab to test the table against.
1Side by side
| Bus | Star | Tree | Ring | Mesh | |
|---|---|---|---|---|---|
| Shape | One shared backbone | Own cable to a central hub | Stars joined to one backbone | Closed loop, one way | Every pair cabled |
| Cables for 6 computers | 7 (backbone + 6) | 6 | 9 (6 + 2 + backbone) | 6 | 15 (6 × 5 ÷ 2) |
| Amount of cable | Least | More than bus | More than star | Moderate | Most by far |
| One cable breaks | Only that computer (backbone: all) | Only that computer | Only that computer (backbone: stars split) | Whole network stops | Nobody cut off |
| Central device fails | No central device | Whole network stops | That star is cut off | No central device | No central device |
| Adding a computer | Easy | Easy, if a hub port is free | Easy | Breaks the ring while you add it | Hard — cable to everyone |
| Finding a fault | Hard | Easy | Moderate | Hard | Easy |
| Cost | Lowest | Moderate | Higher | Moderate | Highest |
Syllabus check
Bus, star and tree are the three the CBSE syllabus names. Ring and mesh are here because many textbooks include them.
Test the table
Pick a shape and a fault. Check each row of the table against what happens.
to
7
separate cables
15 / 15
pairs that can talk
yes
can A reach D?
2Name the topology
Which topology?
Read the description and pick the topology.
1 of 12score 0
Every computer has its own cable running to one hub
3Check yourself
Quick Check
Which topology uses the least cable?
Quick Check
A school wants one network joining three labs, each with its own hub. Which topology fits?