Stands for NetBIOS Extended User Interface, a networking protocol developed by IBM and Microsoft in 1985 that is used for workgroup-size local area networks (LANs) with up to 200 stations. NetBEUI is an extension of the NetBIOS protocol.
NetBEUI was the primary protocol for LAN Manager and Windows for Workgroups. It is a fast and efficient protocol with low overhead that supports both connection-oriented communication (such as communication for mapping drives using the Net Use command and starting services remotely using the Net Start command) and connectionless communication (such as communication for sending datagrams, registering NetBIOS names, and performing NetBIOS name resolution).
NetBEUI is also self-tuning and implements flow control and error detection. It defines a framing mechanism at the transport layer and implements the LLC2 protocol of the Open Systems Interconnection (OSI) reference model for networking.
NetBEUI is supported by all Microsoft Windows network operating systems; its implementation on Windows NT is called the NetBEUI Frame (NBF) protocol.
NetBEUI relies more heavily on broadcast packets than do the TCP/IP and NWLink IPX/SPX-Compatible Transport protocols; you should therefore use it only on smaller networks sized for workgroups. Because NetBEUI is a single-part naming scheme, it is a nonroutable protocol and is generally unsuitable for wide area networks (WANs).