Draw the shape of a network
Somebody trips over a cable in the IT room. Does one PC go offline, or the whole college? It depends on the shape.
You can join six computers in many ways. Put one box in the middle and join every computer to it. Or join every computer to every other one. Each shape works differently when a cable breaks. A network is a group of computers joined together. A topology is the shape of a network.
Key words
| Word | What it means | Example |
|---|---|---|
| Topology | The shape of a network: how its devices are joined. | Star, mesh, tree |
| Network | Computers joined together to share data. | The college network |
| Star | Every device has its own cable to one central device. | An office with one switch |
| Mesh | Devices have many links to other devices, so there are many paths. | The middle of the internet |
| Tree | Stars joined in layers, like the branches of a real tree. | A large college |
| Switch | A box that joins the cables of a network and passes data to the right device. | The box in the network room |
| Physical topology | The real layout of devices and cables. | What you can see |
| VLAN | Virtual LAN. A way to split one switch into separate networks. | Staff and visitors |
| Logical topology | How the data flows from one device to another. | Staff PCs and visitor PCs kept apart |
The cells students fill in are left blank in this preview.
Which shape is it?
Have a go
Which shape is it?
4 questionsHave a go: your answers are marked here and then forgotten. Sign in if you would like your score kept, and to pick up where you left off.Sign in to keep your score
Your answers are marked here and are not kept. A college account keeps every student’s marks.
Benefits and drawbacks
| Topology | Benefits | Drawbacks |
|---|---|---|
| Star | Easy to add a device. One broken cable affects one device. Easy to manage from the centre. | If the central switch fails, the whole network fails. It needs a lot of cable. |
| Mesh | Very reliable: many paths. Data can go around a fault. | Costs a lot. Many cables and ports. Hard to set up and manage. |
| Tree | Grows easily. Each branch can be managed on its own. | If the main switch fails, whole branches lose the network. You must buy more switches. |
The cells students fill in are left blank in this preview.
Try it: links in a full mesh
# In a full mesh, every new device links to every device already there.
devices = 6
links = 0
for new_device in range(1, devices):
links = links + new_device
print(new_device + 1, "devices: links =", links)
# Change 6 to 10. See how fast the links grow.