Types of networks: PAN, LAN, MAN and WAN
Networks are named by how much ground they cover. Zoom out from the phone, watch and earbuds around you (a PAN) to your home (a LAN), a school campus (a CAN), a city fibre ring (a MAN) and the long links between cities (a WAN). Then see why the internet is the biggest WAN, and how a VPN builds a private network on top of it.
5 quick questions
Pick an answer to see why. Your score saves with your progress.
01Your phone, smartwatch and wireless earbuds talk to each other over Bluetooth. What kind of network is that?
A PAN covers a few metres around one person. Bluetooth reaches about 10 m, which is the right size.
02What is a WLAN?
W stands for wireless. It still covers a home or office like any LAN; only the links are radio instead of cables.
03Signals in fibre travel at about two-thirds of the speed of light. Roughly how long does a signal take to cross 1,000 km of fibre?
Two-thirds of light speed is about 200 km per millisecond, so 1,000 km takes about 5 ms one way, and a round trip about 10 ms.
04Which of these is usually true of a WAN, but not of your home LAN?
You own your LAN. Long-distance links belong to carriers, the big telecom companies, and are rented by the organisations that use them.
05How does a VPN make a laptop at home act as if it were on the office network in another city?
A VPN is a virtual network: its links are tunnels through another network, here the internet, rather than cables of its own.
Glossary
- PAN
- Personal area network: a few devices around one person, joined by Bluetooth or USB. About 10 m across.
- LAN
- Local area network: the devices in one home, office or building, on equipment the owner runs, joined by Ethernet or Wi-Fi.
- WLAN
- Wireless LAN: a LAN whose links are radio, such as Wi-Fi.
- CAN
- Campus area network: the LANs of several buildings, such as a school or company site, joined by the organisation's own fibre.
- MAN
- Metropolitan area network: a network across a city, such as a provider's fibre ring, tens of kilometres wide.
- WAN
- Wide area network: links between cities and countries, usually leased from carriers. The internet is the biggest one.
- Carrier
- A large telecom company that owns long-distance links and rents capacity on them to others.
- VPN
- Virtual private network: a private network built from encrypted tunnels through a shared network such as the internet.
Notes and sources
- The sizes are typical, not hard limits: names describe roughly how much ground a network covers. A Bluetooth class 2 radio reaches about 10 m; Ethernet over copper (IEEE 802.3, 1000BASE-T) is specified up to 100 m per cable.
- Signal times use the same rule of thumb as the "Bits on the wire" lesson: about two-thirds of the speed of light, 200 km per millisecond, so 1,000 km takes about 5.0 ms. Real paths are longer than a straight line and add waiting in routers.
- Who owns the links is the big practical difference: you own your PAN and LAN, an organisation its campus, while city and long-distance links are rented from providers and carriers.
- 192.168.1.0/24 and 10.20.0.0/16 are private ranges (RFC 1918); 203.0.113.5 and 198.51.100.0/24 are RFC 5737 documentation addresses. Distances are illustrative.
- A VPN is one example of a virtual network: its links are tunnels through another network rather than cables of its own (RFC 4026). The tunnel's outer packets cross the internet like any others.
- IEEE 802 LAN/MAN Standards Committee
- IEEE Std 802-2014: Overview and Architecture (LANs and MANs)
- IEEE 802.3 Ethernet Working Group
- IEEE 802.11 Wireless LAN (Wi-Fi) Working Group
- IEEE 802.15 Wireless Personal Area Network Working Group
- Bluetooth Core Specification (Bluetooth SIG)
- RFC 4026: Provider Provisioned VPN Terminology
- RFC 4301: Security Architecture for IP (IPsec)
- RFC 1930: Autonomous systems (the networks that make up the internet)
- RFC 1918: Private address ranges
- RFC 5737: IPv4 address blocks reserved for documentation
Quiz Unlocks after the last step.