One cable breaks and the lights go out
In a small office, a cable is cut by a builder. In one office only one computer goes offline. In another, every computer loses its connection.
The difference is the shape of the layout. Choosing the right shape decides how much a fault costs.
By the end of this lesson
Note
I can match a layout to a situation and say what happens to it when a cable or device fails.
Key words
| Word | What it means |
|---|---|
| Network | devices joined so they can share data |
| Topology | the shape of a network |
| Physical topology | how the devices and cables are laid out |
| Logical topology | the path the data follows |
| Node | any device on a network |
| Single point of failure | one part that stops everything if it breaks |
| Backbone | the main cable that other cables join |
The cells students fill in are left blank in this preview.
Starter: what you already know
Have a go
Starter: what you already know
3 questionsYour answers are marked here and are not kept. A college account keeps every student’s marks.
Shape you see, path data takes
The physical topology is how you could draw the cables and devices on a plan of the building. The logical topology is the way data really travels.
They can differ. A Wi-Fi network has devices scattered around a room. Data still goes from each device to the access point, so logically it is a star.
Four layouts
In a star, every node has its own cable to a switch in the middle. In a bus, all nodes share one backbone cable. In a ring, each node joins its two neighbours and data goes round. In a mesh, nodes have many links, so data can take more than one path.
Read the diagram
Have a go
Read the diagram
3 questionsYour answers are marked here and are not kept. A college account keeps every student’s marks.