What plugs into the other end?
You pull a cable through a ceiling and fit a socket. The job is not done. The cable is only useful when something is plugged into it.
A phone, a camera, a switch, a server, a wireless point. An installer must know what each device needs: the kind of port, the power and the place.
Key words
| Word | What it means |
|---|---|
| Network | devices joined so they can share data |
| Firewall | a device that allows or blocks traffic by rules |
| Router | a device that passes data between networks |
| Switch | a device that sends each frame only to the right port |
| Modem | a device that turns data into signals for a phone or cable line |
| WAP | wireless access point: it joins Wi-Fi devices to the cabled network |
| Media converter | a box that changes one cable type to another |
| SFP | small form-factor pluggable: a small module that slides into a switch port |
| PoE | power over Ethernet: power sent down the data cable |
| VoIP | voice over IP: phone calls sent as data |
| Ethernet | the common way to join wired devices in an office |
| IP address | an address for a device on a network |
| MAC address | the address built into a NIC |
| Endpoint | a device at the end of a link, such as a phone or camera |
The cells students fill in are left blank in this preview.
By the end of this lesson
Note
I can name the devices in a cabled installation and say what each one does.
Starter: what you know
Have a go
Starter: what you know
3 questionsYour answers are marked here and are not kept. A college account keeps every student’s marks.
Devices that move and guard data
| Device | What it does | Where it sits |
|---|---|---|
| Firewall | Allows or blocks traffic by rules | Between the site and the internet |
| Router | Passes data between networks by IP address | At the edge, and between subnets |
| Switch | Sends each frame to the right port by MAC address | In a rack, one for each floor or room |
| Hub | Repeats every signal to every port | Old kit. Rarely installed now |
| Bridge | Joins two parts of a network | Between two segments |
| Modem | Turns data into signals for a phone or cable line | Where the provider's line arrives |
The cells students fill in are left blank in this preview.
SFP ports on a switch
Some switches have a socket for an SFP module. The module sets the cable type. A copper module takes a twisted pair. A fibre module takes a fibre pair.
The same switch can serve a short copper run or a long fibre run. You only change the module.
Devices at the edge
| Device | What it does | What the installer checks |
|---|---|---|
| Wireless access point (WAP) | Joins Wi-Fi devices to the cabled network | A cable run to it, often with PoE |
| Wireless range extender | Repeats a Wi-Fi signal to cover more space | Where the signal is still strong |
| Media converter | Changes copper to fibre or fibre to copper | Both cable types, and power |
| VoIP endpoint | A desk phone that sends calls as data | A socket, and PoE |
| CCTV camera | Sends video over the cable | A socket, PoE and the cable length |
| Server | Gives a service such as files or email | A fast cable, power and cooling |
| Network interface | The NIC inside a device that joins the cable | A matching port and speed |
The cells students fill in are left blank in this preview.
The cabling is part of the kit
Cable and its fittings are listed beside the active devices. The best switch is no use on a poor cable. A run that is too long, a plug that does not fit or a cable that cannot carry PoE will stop the device working.