Network Types & Topologies
Network Types by Scale
Network type is mainly about the size and purpose of the network. In theory answers, use the scenario language: personal devices, one site, or geographically separated sites.
| Type | Scale | Example | When to choose it |
|---|---|---|---|
| PAN | Personal area | Phone connected to wireless earbuds or a smartwatch. | Very short range around one person. |
| LAN | One local site | A home, classroom, library or school campus network. | Devices are in the same building or site and need shared resources. |
| WAN | Large geographic area | A company network connecting Perth and Sydney offices. The internet is a WAN. | Separate sites need to communicate over long distances. |
Real scenario
A school building with computers, printers and access points is a LAN. A student's phone connected to earbuds is a PAN. A school connecting its campus to cloud services or another campus uses a WAN connection.
Network Models
Client/server
A central server provides services, files, authentication, applications or storage to client devices.
Best fit
- School or business networks with many users.
- Central backups, user accounts and permissions are needed.
- Data must be managed consistently.
Weakness: server failure or poor configuration can affect many users.
Peer-to-peer
Devices share directly with each other without a dedicated central server.
Best fit
- Small informal networks.
- Low-cost sharing between a few devices.
- Temporary collaboration where central management is not required.
Weakness: harder to secure, back up and manage as the network grows.
Topologies
A topology describes how devices are arranged or connected. The main exam skill is to describe the effect of a failure and justify which topology suits the scenario.
Star
PC | PC-Switch-PC | Printer
Each device connects to a central switch or hub.
- Easy to add or remove devices.
- A single device failure usually affects only that device.
- Central switch failure can stop the network.
Bus
PC--PC--PC--Printer ================== single backbone cable
Devices connect to one main backbone cable.
- Simple and low cost for very small old networks.
- Backbone failure affects the whole network.
- Performance drops as more devices share the cable.
Ring
PC ---- PC | | PC ---- PC
Devices connect in a closed loop, often with data travelling around the ring.
- Can provide orderly data movement.
- A break can disrupt communication unless redundancy is built in.
- Less common in simple modern classroom networks.
Choosing a Topology
Scenario: A small school computer room needs 24 computers connected to a printer and internet access. The technician wants the network to be easy to expand and easy to troubleshoot.
Best answer: A star topology is suitable because each device connects to a central switch. It is easy to add or remove devices, and if one computer cable fails the rest of the network can continue. The weakness is that the central switch is a single point of failure, so the school should protect it and keep a spare or plan for replacement.
Possible Theory Questions and Model Answers
Question 1
Compare a LAN and a WAN.
Model answer: A LAN covers a small local area such as a school or office and is usually managed by one organisation. A WAN covers a much larger geographic area and connects separate LANs, such as offices in different cities or access to the internet.
Question 2
Why is client/server usually better than peer-to-peer for a school?
Model answer: Client/server is better because accounts, permissions, files and backups can be managed centrally. This is important in a school with many users and shared resources. Peer-to-peer is cheaper and simpler, but it becomes harder to secure and manage as the number of devices grows.
Question 3
State one advantage and one disadvantage of a star topology.
Model answer: One advantage is that a single device or cable failure usually affects only that device. One disadvantage is that if the central switch fails, many or all devices connected to it lose network access.