J277 Component 1 · 1.3 Computer Networks

Network Topologies & Hardware

CSHub

Network Types: LAN vs WAN

LAN — Local Area Network
  • • Covers a small geographic area — one building or site
  • • Examples: school network, office, home
  • • Typically owned and managed by the organisation
  • • Uses switches, routers, WAPs
  • • Fast speeds — usually 100 Mbps to 10 Gbps
WAN — Wide Area Network
  • • Covers a large geographic area — cities, countries, global
  • • Examples: the internet, bank networks across branches
  • • Uses infrastructure owned by third parties (ISPs)
  • • Connects multiple LANs together
  • • Generally slower than LAN; uses leased lines / fibre

Wired vs Wireless Connections

Factor Wired (Ethernet / Fibre) Wireless (Wi-Fi)
SpeedFaster, consistentVariable, can be slower
ReliabilityVery reliable — no interferenceInterference from walls, devices
SecurityMore secure — physical access neededEasier to intercept signals
MobilityDevice must be near a cable portMove freely within range
CostHigher (cabling infrastructure)Lower install cost

Network Hardware

Router

Directs data between different networks — typically connects your LAN to the internet (WAN). Uses IP addresses to determine the best path for data packets.

Switch

Connects devices within a LAN. Unlike a hub, a switch sends data only to the specific device it's addressed to — more efficient and secure. Uses MAC addresses.

NIC

Network Interface Card — hardware inside a device that allows it to connect to a network. Every NIC has a unique MAC address. Can be wired (Ethernet) or wireless.

WAP

Wireless Access Point — allows wireless devices to connect to a wired network. Transmits and receives Wi-Fi signals. Often built into home routers.

Transmission Media
Copper Cable (Ethernet)

Electrical signals. Cheaper. Susceptible to interference (EMI). Max ~100m without repeater.

Fibre Optic

Light pulses through glass/plastic. Much faster. Immune to EMI. More expensive. Used for backbone / internet.

Wi-Fi (Radio Waves)

Radio frequency signals (2.4 GHz or 5 GHz). Wireless flexibility. Affected by walls, interference, distance.

Interactive: Topology Explorer

Click each topology to see its diagram and key details. Use the Animate button to watch a data packet travel through the network.

Factors Affecting Network Performance

BW
Bandwidth

The maximum amount of data that can be transferred per second (measured in Mbps or Gbps). Higher bandwidth = faster network.

INT
Interference

Wireless signals disrupted by physical barriers, other devices, or competing Wi-Fi networks on the same channel.

DEV
Number of Devices

More devices sharing the same network means less bandwidth per device. Heavy traffic can cause congestion and slow speeds.

DST
Distance

Signal weakens over distance (especially wireless). Copper cable degrades over ~100m. Fibre optic can carry signals much further.

Activity: Match the Hardware

Drag each hardware item to its correct description.

Router
Switch
NIC
WAP
Fibre Optic
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Directs data packets between different networks, including connecting a LAN to the internet using IP addresses.
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Connects multiple devices within a LAN and sends data only to the intended device using MAC addresses.
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Hardware component inside a device that gives it a unique MAC address and allows it to join a network.
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Broadcasts Wi-Fi signals so wireless devices can connect to a wired network infrastructure.
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Transmission medium that uses pulses of light rather than electrical signals — immune to interference, very high speed.