The café with the old Wi-Fi
A café has used the same Wi-Fi password for eight years. The Wi-Fi box is old. It only offers an old security setting.
A customer in the corner has been reading the café's traffic for a week. It took him ten minutes to get in.
The setting matters. In this lesson you meet three technologies: PPP, SDN and WPA.
Key words
| Word | What it means |
|---|---|
| Protocol | an agreed set of rules for how devices talk to each other |
| PPP | the point-to-point protocol: rules for a direct link between two devices |
| Authentication | proving who you are, for example with a password |
| SDN | software-defined networking: one program controls many network devices |
| Controller | the central program in SDN that tells the devices what to do |
| Automation | getting a computer to do a repeated task |
| WPA | Wi-Fi protected access: rules that protect a Wi-Fi network |
| Encryption | scrambling data so only the right key can read it |
| Network | computers and devices joined together so they can share data |
| Router | a device that passes packets between networks |
| IP address | a number that names a device on a network |
| Packet | a small piece of data sent over a network |
The cells students fill in are left blank in this preview.
By the end of this lesson
Note
I can describe PPP and SDN, and compare WPA 1, WPA 2 and WPA 3.
Starter
Have a go
Starter
3 questionsYour answers are marked here and are not kept. A college account keeps every student’s marks.
PPP: a direct link
The point-to-point protocol (PPP) sets up a direct link between two devices. Think of a phone call between two people, not a group chat.
PPP checks who is calling, using a username and password. It can give the caller an IP address. It also finds damaged data.
Many broadband lines still use a version called PPPoE. Your router logs in to your internet provider with PPP.
SDN: one brain for many devices
A normal switch or router decides for itself where data goes. In a big network, you must set up each box one by one.
Software-defined networking (SDN) splits the thinking from the moving. A central controller makes the decisions. The devices only forward packets as they are told.
The gain is automation. One change at the controller reaches hundreds of devices in seconds.
Quick check
Have a go
Quick check
3 questionsYour answers are marked here and are not kept. A college account keeps every student’s marks.