LAN (Local Area Network)

Local Area Networks not only provide the necessary connection between gamers’ computers at LAN parties. They’re now also used in many households, where multiple digital end devices need to access the internet or home printer. But what exactly is a LAN, how is it different from other types of networks and which technologies does it involve?

LAN is the abbreviation for Local Area Network. It refers to networks within a limited area. LANs are typically used in private households or in companies to set up home or corporate networks. This allows the various devices to communicate with each other.

A LAN comprises at least two end devices, but it can also link several thousand devices to one another. If larger distances need to be bridged, however, this is normally achieved using MANs and WANs. A Local Area Network can connect computers, smartphones, printers, scanners, storage devices, servers and other network devices with each other and to the internet. If a printer is only connected to a computer via a USB cable, for example, usually only this PC will be able to access the device. But connecting the printer to the network allows multiple devices in the area to use the printer.

Other terms also crop up in the context of LANs: WANs, WLANs, and MANs may sound similar, but they refer to different types of networks. WLAN stands for Wireless Local Area Network and is also known internationally as Wi-Fi. Here, computers are connected by wireless communication. This is not the case with MANs and WANs. These networks only differ from a LAN in terms of size.

WAN stands for Wide Area Network. This kind of network connects individual LANs or MANs even over large distances. A WAN can cover entire countries or continents. By contrast, a MAN is a Metropolitan Area Network. This type of network is the LAN’s big brother, connecting devices within a city or metropolitan region. MANs mostly use fibre optic technology to connect multiple LANs. A MAN can encompass up to 100 kilometres.

Nowadays, virtually all LANs are realized via Ethernet. In the past, LANs were also implemented using the following technologies which nowadays hardly play a role anymore:

• Token Ring
• DECNET
• FDDI (still used in some cases to connect Ethernet and Token Ring technology)
• ARCNET (outdated but still used in industrial automation)

Ethernet achieves data transmission rates of up to several hundred Gbits/s. The technology uses either twisted pair cable or – the newer method – fibre optic cable. While conventional copper cables can only bridge up to 100 meters, fibre optic cables can stretch over several miles. In order to ensure that the data actually arrives via the cable connections and that data packets don’t block each other, technology such as CSMA/CD is used. In the case of a WLAN in which data packets are transmitted wirelessly, CSMA/CA is utilised.

An Ethernet LAN can be divided into multiple virtual LANs (VLANs) or physical LANs. The virtual structure enables administrators to partition networks without needing to implement major infrastructure changes.

Switches and routers are used to organise Local Area Networks. The hardware acts as an interface and governs the connections between the individual network participants, ensuring the data packets reach their destination. Also, when data is transmitted from a LAN to the internet or information is to be accessed from other networks or data centres, the connection occurs via a router. By contrast, repeaters and hubs which previously performed similar tasks are scarcely used in modern LANs.

Network cables, network sockets, and network patches are also used as physical components when setting up a LAN. They connect the individual end devices and servers with each other and offer network administrators and home admins the ability to neatly install the network in the office or at home.