Windows NT Networking Architecture

Windows NT is a complete operating system with fully integrated networking capabilities. These capabilities differentiate Windows NT from other operating systems such as MS-DOS, OS/2, and UNIX for which network capabilities are installed separately from the core operating system.

Integrated networking support means that Windows NT offers these features:

• Support for both peer-to-peer and client-server networking. All Windows NT computers can act as both network clients and servers, sharing files and printers with other computers and exchanging messages over the network. Windows NT Server also includes features needed for full-scale servers, such as domain management tools.
• The ability to easily add networking software and hardware. The networking software integrated into Windows NT lets you easily add protocol drivers, network card drivers, and other network software. Windows NT includes four transport protocols—IPX/SPX (NWLink), TCP/IP, NBF (Windows NT NetBEUI), and DLC.
• Interoperability with existing networks. Windows NT systems can communicate using a variety of transport protocols and network adapters. It can also communicate over a variety of different vendors' networks.
• Support for distributed applications. Windows NT provides a transparent Remote Procedure Call (RPC) facility. It also supports NetBIOS, Sockets, and the Windows Network (WNet) APIs and named pipes and mailslots, for backward compatibility with LAN Manager installations and applications.
• Remote access to networks. Windows NT Remote Access Service (RAS) clients can dial into any PPP or SLIP server. Windows NT RAS servers support any remote clients using IPX, TCP/IP, or NetBEUI using PPP. For additional information about RAS, see Chapter 9, "Using Remote Access Service."
• Print and File sharing, and AppleTalk® routing for Macintosh® clients.

This chapter describes the Windows NT networking architecture and how it achieves each of these goals. For perspective, the next section provides a brief explanation of two industry-standard models for networking — the Open System Interconnection (OSI) reference model and the Institute of Electrical and Electronic Engineers (IEEE) 802 project model. The remainder of the chapter describes the Windows NT networking components as they relate to the OSI and IEEE models and as they relate to the overall Windows NT architecture.