Access Points, Modems and Cabling in the Lab
What gets us on the Internet from the classroom?
- Explain the role of a wireless access point (AP)
- Describe what a modem does
- Trace a packet from a phone to a public website
Overview
The final pieces of the LAN puzzle are the wireless access point and the modem. Together with the switch and router they let a mobile phone in the classroom reach Wikipedia halfway around the world.
Wireless access point
An AP is essentially a wireless switch — it bridges radio-Wi-Fi devices to the wired LAN. In a school, several APs can share the same SSID so students walking between rooms stay connected.
Modem
A modem MOdulates and DEModulates — turning digital signals from your LAN into a signal that fits the ISP's medium (DSL, cable, fibre, 4G). At school it is often built into the same box as the router.
End-to-end example
Phone → AP (Wi-Fi) → Switch (Ethernet) → Router (routes to WAN) → Modem (talks to ISP) → ISP network → Internet → target server. Reverse for the reply. All in a fraction of a second.
Connect a Phone
- Extend the previous lab: add a router, connect it to the switch, and enable Wi-Fi.
- Join the Wi-Fi from a phone. Ping a PC and confirm connectivity.
- Draw the full topology and label every device.
- What is an SSID?
Reveal answer
The name broadcast by a Wi-Fi network.
- What does a modem do?
Reveal answer
Converts LAN signals into a form the ISP's medium can carry, and back.
- Which device bridges Wi-Fi to a wired LAN?
Reveal answer
A wireless access point (AP).
Rename a home Wi-Fi hotspot's SSID. Explain why you should never use your full name or address in it.