Network hardware
From stand-alone computers to a LAN
A stand-alone computer isn't connected to any others. To join some into a LAN, each needs a way to connect, something to connect to, and something to carry the data between them.
| Hardware | What it does |
|---|---|
| NIC (network interface controller or card) | Built into every networked device. It lets the device connect to a network, by cable or wirelessly, and has the device's unique MAC address |
| Switch | Connects the devices in a LAN. It sends data only to the device it's meant for, using MAC addresses |
| Wireless access point (WAP) | Lets devices join a wired network wirelessly, using Wi-Fi |
| Router | Sends data between different networks, such as from a LAN to the internet, using IP addresses |
| Transmission media | The cables or radio waves the data travels through |
Key terms
Transmission media
The transmission media are what the data travels through between devices.
| Medium | How data travels | Strengths | Weaknesses |
|---|---|---|---|
| Copper cable (Ethernet cable) | As electrical signals | Cheap; easy to fit | Slower over long distances; can pick up interference |
| Fibre-optic cable | As pulses of light | Very fast, over long distances; no electrical interference | More expensive |
| Radio waves (wireless) | Through the air | No cables, so devices can move around | Slower; weakened by walls and distance; can be intercepted |
Fibre-optic cables carry the internet's data between cities and under the oceans. Copper cables and radio waves are common in homes and offices.
Key terms
Your router at home
The box called a 'router' at home usually does several jobs in one:
- a router, sending data between your home LAN and the internet;
- a switch, with a few sockets for Ethernet cables;
- a wireless access point, so phones and laptops can connect by Wi-Fi;
- a modem, which connects to the internet service provider's line.
In a school or office, these are usually separate devices, as many more computers have to be connected.
Common mistake
A switch connects devices within one network; a router connects different networks. Don't mix them up.