NetBEUI

Overview of Windows 2000 NetBEUI

NetBIOS Extended User Interface (NetBEUI) was one of the earliest protocols available for use on networks composed of personal computers. It was designed around the Network Basic Input/Output System (NetBIOS) interface as a small, efficient protocol for use in department-sized local area networks (LANs) of 20 to 200 computers, which would not need to be routed to other subnets. At present, NetBEUI is used almost exclusively on small, non-routed networks composed of computers running a variety of operating systems, including: Microsoft® Windows NT® Server 3.5 and later, Microsoft® Windows NT® Workstation version 3.5 and later, Microsoft® LAN Manager, Microsoft® Windows® for Workgroups, Microsoft® Windows® version 3.1, Microsoft® Windows® 95, Microsoft® Windows® 98, Microsoft® Windows NT® version 3.1, and LAN Manager for UNIX, as well as IBM PCLAN and LAN Server.

Windows 2000–based NetBEUI, known as NetBIOS Frame (NBF), implements the NetBEUI version 3.0 specification. NBF is the underlying implementation of the NetBEUI protocol installed on a computer running Windows 2000. It provides compatibility with existing LANs using the NetBEUI protocol, and is compatible with the NetBEUI protocol driver included with previous versions of Microsoft networking products. In addition, NBF:

Uses the Windows 2000–based Transport Driver Interface (TDI), which provides an emulator for interpretation of NetBIOS network commands.
Uses the Windows 2000–based Network Device Interface Specification (NDIS) with improved transport support and a full 32-bit asynchronous interface.
Uses memory dynamically to provide automatic memory tuning.
Supports dial-up client communications with a remote access server.
Provides connection-oriented and connectionless communication services.
Removes the NetBIOS session number limit.

The following definitions are provided to clarify terms used later in this chapter:

Network Basic Input/Output System (NetBIOS) is software developed by IBM; provides the interface between a computer's operating system, the I/O bus, and the network; a de-facto network standard.
NetBIOS Extended User Interface (NetBEUI) is the original personal computer networking protocol and interface designed by IBM for their LAN Manager server. NetBEUI implements the OSI LLC2 protocol and has a limitation of 254 session connections.
Windows 2000 NetBEUI 3.0, also known as NetBIOS Frame Format Protocol (NBFP), is the Microsoft implementation of the IBM NetBEUI protocol. It eliminates the previous NetBEUI limitation of 254 sessions to a server and uses the Microsoft TDI layer as an interface to NetBIOS.