Types of LAN Network

LAN stands for Local Area Network (as opposed to WAN, or Wide Area Network), which commonly refers to how a connection to the Internet is made. LANs are used to connect computers that are geographically close together, whether inside a room or inside a building. This allows people to share files and printers, play computer games together and even send music to a stereo system or videos to a television.

The Basic LAN

The basic type of LAN is connected by Ethernet cables to a router or hub (modern routers usually integrate hubs). A router allows all computers connected to it to access a high-speed modem connected to the router. Each computer has an IP (Internet Protocol) address, but a computer on the other side of the Internet will only see the router's IP address. This, and a router's built-in firewall, creates a safer environment for accessing the Internet. (Firewalls are used to filter out unauthorized access to the network.)

Wired LAN Speeds and Connections

A wired connection has two common connection standards: 100BASE-T and 1000BASE-T. The first one transfers data at up to 100 megabits per second (Mb/s), and the second one transmits at 1000 Mb/s or 1 gigabit per second (Gb/s). The second one is also known as Gigabit Ethernet. Most modern motherboards integrate this into their circuitry, rather than requiring the user to obtain an Ethernet card. Ethernet cables can run hundreds of feet without losing signal quality.

Wireless LAN

Another standard in the mix is wireless Ethernet. This allows you to cut out cables altogether. You can transmit data through walls, floors and ceilings without having to drill holes. It is handier for people who use laptops and other mobile devices, since they can just turn on the device and have access to the network without plugging everything in. However, the transfer speeds are not as fast. The fastest protocol, 802.11n, moves data at up to 300 Mb/s. Wireless Ethernet is also susceptible to interference from devices such as a microwave or cordless phone.

Wireless Encryption

Furthermore, wireless Ethernet also requires encryption. Without it, anyone close enough to the wireless router can capture and read all the data going back and forth. For this reason, a wireless Ethernet user will want to use WPA2 encryption. Unfortunately, it is possible to break into a WPA2 network by using a brute force attack. This method uses software that sends a constant stream of password guessing to the router until it finds the right one. A wireless network administrator should use a password that is difficult to guess.

Corporate LANs

Wired LAN connections are capable of even higher speeds, although these are usually limited to corporate environments. 10 Gigabit Ethernet enters the picture here, as does Fibre Channel, which is popular in Hollywood's digital post-production facilities dealing with editing and special effects.

References

• 802.11n guide
• Ethernet explained