Local Area Network and LAN Protocols

Local Area Network (LAN) is a data communications network connecting terminals, computers and printers within a building or other geographically limited areas. These devices could be connected through wired cables or wireless links. Ethernet, Token Ring and Wireless LAN using IEEE 802.11 are examples of standard LAN technologies.  

Ethernet is by far the most commonly used LAN technology. Token Ring technology is still used by some companies. FDDI is sometimes used as a backbone LAN interconnecting Ethernet or Token Ring LANs. WLAN using IEEE 802.11 technologies is rapidly becoming the new leading LAN technology for its mobility and easy to use features.

Local Area Network could be interconnected using Wide Area Network (WAN) or Metropolitan Area Network (MAN) technologies. The common WAN technologies include TCP/IP, ATM, Frame Relay etc. The common MAN technologies include SMDS and 10 Gigabit Ethernet.

LANs are traditionally used to connect a group of people who are in the same local area. However, the working group are becoming more geographically distributed in today's working environment. There, virtual LAN (VLAN) technologies are defined for people in different places to share the same networking resource.

Local Area Network protocols are mostly at data link layer (layer 2). IEEE is the leading organization defining most of the LAN protocols.

Protocol Structure - Local Area Network and LAN Protocols