Network Hardware

AQA 4.7.1 — Network hardware

Retrieval: the previous lesson described LANs and WANs in outline. This lesson opens up the actual physical devices that make a network like that work — and what each one specifically does.

Key vocabulary

Switch — connects devices within one LAN, directing each piece of data only to the specific device it's addressed to.
Router — connects separate networks together (e.g. a home LAN to the wider Internet), directing traffic between them.
Wireless Access Point (WAP) — lets wireless devices join a network without a physical cable.
Network Interface Card (NIC) — the hardware inside a device that lets it connect to a network at all.

Understand — different devices solve different problems

A switch solves the problem of many devices on one network needing to reach each other efficiently — it learns which device is on which cable and sends data directly there, rather than blasting every message to every device. A router solves a completely different problem: getting data between separate networks that wouldn't otherwise know how to reach each other at all — most commonly, a home or school's own LAN and the vast WAN that is the Internet.

Visualise — a small organisation's network

 [Laptop]      [Laptop]         [Wireless
    │  (cable)    │  (cable)     phone/tablet]
    └──────┬──────┘                   │
         Switch ─────────────────  WAP
              │
            Router ─────────────── Internet

Devices on cables connect to the switch; wireless devices connect via the WAP (which itself usually plugs into the switch); the router is the single gateway out to the wider Internet.

Apply to scenario — network diagnosis

A user reports: "I can open files shared on other computers in the office, and print to the shared printer, but I can't load any websites at all." Using the diagram above, which single device is the most likely point of failure, and why?

(The router. Being able to reach other devices and the shared printer on the same LAN shows the switch and local cabling are working correctly — the failure is specifically with traffic leaving the LAN for the wider Internet, which is exactly the router's job.)

Compare — client-server vs peer-to-peer

	Client-server	Peer-to-peer
Structure	A central server provides resources/services; clients request them	Every device is equal, sharing resources directly with each other
Management	Centralised — easier to control security, backups, permissions	Decentralised — no single point of control
Cost	Requires dedicated server hardware and expertise to maintain	Cheaper to set up — no dedicated server needed
Reliability	If the server fails, dependent services may become unavailable for everyone	No single point of failure, but harder to guarantee data is backed up consistently

Recommend — matching hardware and structure to need

A small design studio of 4 freelancers sharing files casually, with no dedicated IT staff, is well suited to a simple peer-to-peer setup — the cost and complexity of a dedicated server isn't justified by their needs. A school managing hundreds of student accounts, shared coursework storage, and centrally-enforced security policies needs the centralised control a client-server structure provides — peer-to-peer would make consistent security and backups far harder to guarantee across so many devices.

Common mistake

Confusing the roles of a switch and a router: a switch connects devices within the same network; a router connects separate networks to each other. A home "router" bought from a shop is usually actually doing both jobs in one box, which is exactly why the distinction gets blurred in everyday language.

Challenge

A small office reports that their network is slow specifically when many people are on video calls at once, but fine otherwise. Using the ideas in this lesson, suggest one hardware-related factor (beyond simply "the network is slow") that could specifically explain this pattern, and justify your reasoning.

Looking ahead: the next lesson (Protocols and Standards) covers the rules that let devices communicate reliably — this hardware is what those rules actually run on.

Learn