Bus topology is a network setup where all computers (nodes) are connected to a single central cable called the backbone or bus. Think of it like a main road (bus cable) and houses (PCs) connected along the road.
How it Works
- All devices share one communication cable.
- When a PC sends data, the signal travels both directions along the bus.
- Every PC receives the data, but only the intended device accepts it.
- Terminators are placed at both ends of the cable to stop signal reflection.
The Terminator
A terminator is used at both ends so that signals do not bounce back and create network errors.
â ī¸ Critical: Backbone Failure
If the backbone cable is cut or damaged at any point, the entire network goes down immediately. All communication stops because there's no alternative path for data. This is the biggest weakness of bus topology!
Data Flow Example
Suppose PC1 sends data to PC4:
- PC1 puts data on the bus cable.
- The signal travels across all PCs (PC2, PC3).
- Only PC4 reads the data; others ignore it.
Advantages
- â Simple and easy to set up.
- â Requires less cable than star or mesh.
- â Good for small networks.
Limitations
- â If the main cable fails, entire network goes down.
- â Only one device can send data at a time.
- â Adding many PCs decreases speed.
Why Bus Topology Is Rare Today
Modern networks use Star Topology with switches because bus topology is slower, unreliable for large networks, and hard to troubleshoot.