Network Navigator

Network Navigator 🧭

A **network** is two or more devices connected so they can share data and resources. To navigate this topic you need four things: the **types** of network, the **protocols** that run on them, the **layered model** they're organised into, and how they're kept **secure**. Let's chart it.

Networks come in sizes

Networks are grouped by the **area** they cover: • **PAN** (Personal Area Network) — tiny, one person's own devices, e.g. earbuds paired to a phone over Bluetooth. • **LAN** (Local Area Network) — a single site like a home, school or office; the organisation usually owns all the hardware. • **WAN** (Wide Area Network) — spread over a large geographic area, connecting LANs together. The internet is the biggest WAN of all; its infrastructure is usually leased from third parties.

Match the scale

Name that network

A school connects all the computers across its one building so they can share a printer and files. What type of network is that?

• LAN
• WAN
• PAN

Wired vs wireless 📶

The same LAN can connect devices with cables (**wired**, e.g. Ethernet) or over radio (**wireless**, e.g. Wi-Fi): • **Wired** — usually **faster** and more **reliable**, and more **secure** (you need physical access to plug in). But no mobility and cabling costs. • **Wireless** — **mobility** and easy to add devices, but typically **slower**, prone to interference, and **easier to intercept**.

Why choose wired?

Pick the TWO genuine advantages of a **wired** connection over wireless.

• Usually faster and more reliable
• Harder to intercept — needs physical access
• Lets devices move around freely
• Needs no cabling to install

What is a protocol? 📜

A **protocol** is a set of **rules** governing how devices communicate — so devices made by different manufacturers can still understand each other. The roster you must know: **TCP**, **IP**, **HTTP**, **HTTPS**, **SMTP** and **IMAP**.

One line each 🏷️

Learn a one-line purpose for every protocol — examiners want precision: • **TCP** — splits data into **packets** and reassembles them, ensuring reliable delivery. • **IP** — **addresses** and **routes** packets across networks. • **HTTP** — requesting and sending **web pages**. • **HTTPS** — HTTP **plus encryption** (secure web pages). • **SMTP** — **sending** email. • **IMAP** — **retrieving** email from a mail server.

Match the protocol

The exam favourite

HTTPS is used for secure websites. What does it add to plain HTTP?

• Encryption
• Faster page loading
• Support for images and video
• The ability to send email

TCP and IP team up

TCP breaks the data into _____ and reassembles them at the other end; IP then _____ each one to the right destination.

A stack of layers 🥞

Rather than one giant tangle of rules, networking is split into the **4-layer TCP/IP model** — four layers, each with one job. From the top (closest to your app) down to the hardware: **Application → Transport → Internet → Link.**

What each layer does 🗂️

Each layer owns part of the journey, and each protocol lives at one layer: • **Application** — where network programs and their protocols run: **HTTP, HTTPS, SMTP, IMAP**. • **Transport** — splits data into packets and reassembles them: **TCP**. • **Internet** — addresses and routes packets between networks: **IP**. • **Link** — the physical hardware and connection carrying the data on the local network.

Stack the layers

An interactive activity.

Which layer?

Locate the protocol

At which layer of the TCP/IP model does the **IP** protocol operate?

• Internet layer
• Transport layer
• Application layer
• Link layer

Why bother layering? 🎯

This is a classic grade-9 question. Layering helps because: • **Interchangeable** — each layer is self-contained, so you can change one (swap Wi-Fi for Ethernet at the Link layer) without touching the others. • **Simpler to develop and troubleshoot** — a problem can be traced to one layer, and each layer can be built and tested on its own.

Keeping it secure 🛡️

Finally, four ways networks are protected: • **Authentication** — proving who you are (e.g. a username and password). • **Encryption** — scrambling data so it is useless if intercepted. • **Firewall** — filters traffic entering and leaving, blocking unauthorised access. • **MAC address filtering** — only lets known, listed devices onto the network.

Match the safeguard