One of the goals of Windows NT's designers was to tightly integrate network protocols and services with the base operating system. Portability to a variety of processors (including RISC and Alpha chips) and scalability, which is made possible through symmetric multiprocessing, make Windows NT Server a desirable superserver platform for developing scalable network-server applications and services.
Packaged with Windows NT and Windows NT Server are several built-in networking protocols and APIs. Windows NT protocols include IPX/SPX, TCP/IP, and NetBEUI. Windows NT Server includes these three protocols, as well as AppleTalk. Supported networking APIs include NetBIOS, DCE RPC (Distributed Computing Environment remote procedure call), and Windows Sockets (Win-Sock).
The figure ``Windows NT Networking'' illustrates
the relationships among the base networking components in Windows NT. NDIS (Network Driver Interface Specification) enables network protocols to run unmodified over different types of network hardware and media. The transports reside at the next level. All the transport protocols share a common TDI (Transport Device Interface), which provides a kernel-mode interface and user-mode programming interfaces for Windows NT's file and print components.
Another design goal for Windows NT networking was to provide an architecture on which interfaces and protocols can be strategically layered and extended. As the figure ``API Layering'' shows, the strategic interface and protocol layers include WinSock, DCE RPC, and Remote OLE.
Currently, a client/server application can choose to talk directly to WinSock or DCE RPC. In the future, Microsoft plans to add the ability to remotely call OLE objects.
Distributed object technology, such as Remote OLE, will enable developers of distributed applications to
divest themselves of knowledge of communications tasks. Remote OLE is built on top of DCE RPC, utilizing such DCE elements as NDR (Network Data Representation) for data marshaling, authenticated packets, and encrypted sessions.
Figure: API Layering
Windows NT-based client/server applications can talk directly to WinSock, DCE RPC, or, in the future, Remote OLE.
Figure: Windows NT Networking
In the Windows NT networking architecture, NDIS allows protocols to run unmodified over a variety of network hardware and media. TDI provides a kernel-level interface.
Windows NT Network Architecture
