What is a Topology?
A network topology is the arrangement (layout) of devices and connections in a computer network.
You need to be able to discuss the pros and cons, and label:
- Star network topology
- Mesh network topology
- Partial-mesh network topology
Star Network Topology
- All devices are connected directly to a central network switch.
- The switch sends data only to where it is needed
- Star is the most popular wired network topology
In an exam, you may be expected to draw a star network. Remember to label each device, including the network switch at the centre.
Advantages
- If one connection fails, only one device is affected
- Consistent performance, even when the network traffic is heavy
Disadvantages
- Central point of failure — if the network switch fails, the whole network fails
- Expensive — requires a network switch and lots of Ethernet cable
Mesh Network Topology
- Every device (node) is connected to every other device
- No central connection point
- Can be wired or wireless
Advantages
- Very resilient. If a connection fails, data a routed along other connections
- Fast — data can be split across many routes to avoid busier connections
- Can cover large distances
Disadvantages
- Very complex to set up and maintain
- Wired mesh networks require lots of cabling and networking hardware, although wireless mesh networks overcome this
Partial Mesh Network Topology
In a partial mesh network, nodes have several connections to other nodes, but not necessarily to all other nodes. This overcomes some of the complexity and cost of a full mesh network whilst still providing a high level of resiliance and speed.