A network topology describes how devices are arranged and connected in a network. In IB Computer Science, students are expected to understand common network topologies, compare their advantages and disadvantages, and explain why a particular topology is suitable for a given scenario.
The most important topologies for IB students are star, mesh, and hybrid.
What Is a Network Topology?
A network topology defines:
- How devices are physically or logically connected
- How data flows between devices
- How faults affect the network
Topology choice affects:
- Performance
- Reliability
- Cost
- Scalability
IB exam questions often test application of topology knowledge, not just definitions.
Star Topology
In a star topology, all devices are connected to a central device, usually a switch.
How It Works
- Each device has a direct connection to the central switch
- All data passes through the central device
Advantages
- Easy to install and manage
- Failure of one cable does not affect others
- Simple fault detection
- High performance in small to medium networks
Disadvantages
- Central device is a single point of failure
- Requires more cabling than some topologies
In IB exams, star topology is commonly linked to:
- School networks
- Office LANs
Mesh Topology
In a mesh topology, devices are connected to multiple other devices.
How It Works
- Data can take multiple paths to reach its destination
- Full mesh connects every device to every other device
Advantages
- Very high reliability
- No single point of failure
- Data can be rerouted if a connection fails
Disadvantages
- Expensive to install
- Complex to manage
- Requires a large amount of cabling
Mesh topology is often associated with:
- Critical systems
- Military or emergency networks
Hybrid Topology
A hybrid topology combines two or more different topologies.
How It Works
- Different sections of a network use different topologies
- These sections are connected together
Advantages
- Flexible and scalable
- Can be customised to meet specific needs
- Combines strengths of multiple topologies
Disadvantages
- More complex design
- Higher cost
- Requires careful planning
Hybrid topologies are common in:
- Large organisations
- Enterprise networks
- Campuses
Comparing Star, Mesh, and Hybrid Topologies
Strong IB answers compare topologies clearly:
- Star: simple, centralised, easy to manage
- Mesh: highly reliable, expensive, complex
- Hybrid: flexible, scalable, complex
Students should link topology choice to requirements.
How Topologies Appear in IB Exams
IB questions may ask students to:
- Identify a suitable topology for a scenario
- Explain advantages and disadvantages
- Compare two topologies
- Discuss reliability and fault tolerance
Justifying choices earns higher marks.
Common Student Mistakes
Students often:
- Forget the central device in star topology
- Confuse mesh with peer-to-peer networks
- Describe hybrid too vaguely
- Ignore cost and scalability
Precision matters.
Final Thoughts
Network topologies determine how data flows, how reliable a network is, and how easy it is to manage. Star, mesh, and hybrid topologies each solve different problems, and understanding their trade-offs is essential for IB Computer Science success.
