Communication Technologies Grade 12
Internet access technologies, network hardware, remote access, VPNs, encryption and security services.
Internet Access Technologies
| Technology | Description | Speed |
|---|---|---|
| ADSL | Uses telephone copper lines; download faster than upload | Moderate (up to ~20 Mbps) |
| Fibre | Light signals through fibre optic cables; very fast and stable | Very fast (100 Mbps–1 Gbps+) |
| WiMAX | Long-range wireless broadband; used in rural/remote areas | Moderate |
| 4G/LTE | Mobile data network; widely available | 5–100 Mbps |
| 5G | Newest mobile network; very low latency; supports IoT, VR, autonomous vehicles | 50 Mbps–10 Gbps |
Network Hardware Summary
| Device | Function |
|---|---|
| Switch | Connects devices in a LAN; sends data only to the intended device |
| Router | Connects networks; routes data between them; assigns IP addresses |
| Modem | Converts digital ↔ analogue; connects to ISP |
| All-in-one | Home devices that combine modem + router + switch + Wi-Fi access point |
| NIC | Hardware in each device that connects it to the network |
Remote Access
Accessing a device or network from another physical location.
- LAN remote access: access shared folders from another PC in the same building
- Internet remote access: access home/work files from anywhere (Google Drive, remote desktop)
VPN — Virtual Private Network
Creates an encrypted tunnel over the Internet, allowing secure remote access to a private network.
- Hides your IP address and location
- All data is encrypted — safe on public Wi-Fi
- Used by companies for remote workers to securely access internal systems
Encryption & Security
| Concept | Description |
|---|---|
| Encryption | Converts readable data into unreadable code. Only someone with the correct key can decrypt it. |
| SSL/TLS | Protocol securing communication between browser and server (HTTPS). Uses public/private key pairs. |
| Digital certificate | Issued by a trusted Certificate Authority. Verifies the website is legitimate. |
| Firewall | Filters incoming and outgoing traffic based on security rules |
| MFA | Multi-Factor Authentication — requires password + second factor (OTP, fingerprint) |
| OTP | One-Time PIN — valid for one login only; prevents replay attacks |
BitTorrent (Peer-to-Peer Sharing)
A protocol that splits large files into pieces shared between many users simultaneously.
- Benefits: very fast for large files, efficient bandwidth use
- Risks: often used for illegal (pirated) content; potential malware; your IP is visible
- Legal uses: Linux distribution downloads, game updates, large software releases