WINDOWS NT Network Architecture Amy, Mei-Hsuan Lu CML/CSIE/NTU August 19, 1998

2 Outline Introduction Major Networking Componennts Open Network Architecture Distributed Applications Corporation-Wide Networking and Distributed Security

3 Introduction Goal Interoperate with existing versions of LAN Manager running on other operating systems Allow applications to access non-Microsoft file systems on networks other than LAN Manager without modifying their code Provide the proper facilities to construct distributed applications, such as Microsoft SQL Server, transaction processing applications, and so forth

4 Introduction History File-locking and record-locking in MS-DOS 3.1 FAT file system (1984) Microsoft Networks (MS-NET)  Redirector - accepts and sends a requests to a remote server  Server Message Block (SMB) protocol - formatting messages  Network Server - a dedicated software on the remote computer  Uniform Naming Convention (UNC)

5 Introduction OSI Model and Windows NT Networking Components Fig 9-2

6 Major Network Components Simplified Client-Side View of Network I/O Fig 9-3

7 Major Network Components Simplified Server-Side View of Network I/O Fig 9-4

8 Major Network Components Network APIs Win32 I/O API Win32 network (Wnet) API Win32 named pipe and mailslot APIs  mailslot provides one-to-many and many-to-one communication mechanisms NetBIOS API  backward compatibility Windows Sockets API Remote procedure call (RPC) facility  run time library and compiler

9 Major Network Components Difference Routes to the Network Fig 9-5

10 Major Network Components Redirector Access remote files, named pipes, and printers Provides a “file system” that behaves like a local file system (responsible for recovery) implements the SMB protocols (works with existing MS-NET, allows access to MS-DOS, Windows, and OS/2) - An Enhanced Version Device Object : \Device\Redirector Asynchronous I/O mode

11 Major Network Components Redirector (Cnot.) Transport driver interface (TDI) : used by director to transmit SMBs to the various transport drivers loaded into Windows NT Virtual channel

12 Major Network Components Server A Server receives and processes requests from redirectors Implements as a file system driver 100 percent compatible with existing MS- NET and LAN manager SMB protocols Asynchronous I/O mode

13 Major Network Components Name Resolution Fig 9-7 Fig 9-8

14 Open Architecture Provides access to non-Microsoft systems for resource connection and network browsing and for remote file and device I/O through a common Win32 API (the Wnet API) Allows multiple network transport protocol drivers to be loaded at the same time and allows redirectors to call a single, common interface to access them Supplies an interface and environment (NDIS) for network card drivers to access Windows NT transport drivers and to gain protability to future MS-DOS systems

15 Open Architecture User-Mode Access to Remote File Systems Multiple provider router (MPR)  a DLL that determines which network to access when an application uses the Win32 WNET API for browsing remote file systems Multiple UNC provider (MUC)  a driver that determines which network to access when an application uses the Win32 I/O API to open remote files

16 Open Architecture Multiple Provider Software Fig 9-9

17 Open Architecture Multiple UNC Provider (MUP) Fig 9-11

18 Open Architecture Transport Protocols Transport protocols are implemented as drivers, like redirectors and servers Transport driver interface (TDI) - allows redirectors and servers to remain independent from transports TDI supports both connection-based and connectionless transmission

19 Open Architecture Transport Driver Interface Fig 9-13

20 Open Architecture Transport Protocols NetBEUI (NetBIOS Extended User Interface) TCP/IP (Transmission Control Protocol/Internet Protocol) - operates in a STREAMS compatible environment IPX/SPX (Internet Packet Exchange/ Sequenced Packet Exchange) DECnet transport AppleTalk XNS (Xerox Network Systems)

21 Open Architecture NDIS Fig 9-14

22 Distributed Application Environment An extension of the client/server model  In local client/server model, the two processes use a message-passing facility called local procedure call (LPC) to communicate across their address space Windows NT is not a distributed operating systems

23 Distributed Application Environment OS Support A way to create and run parts of an application on both local and remote computers Application-level mechanisms for passing information between local and remote processes Support for network operations, including transport facilities

24 Distributed Application Environment Remote Procedure Call (RPC) Some of the procedure libraries in an RPC application execute on remote computers, wearers others execute locally Provides a procedural view of networked operations rather than a transport-centered view stub procedures - takes the parameters passed to it and marshals them for transmission across the networks

25 Distributed Application Environment Remote Procedure Call (RPC) Fig 9-15 Fig 9-16

26 Distributed Application Environment RPC Run Time Fig 9-17

27 Distributed Application Environment Remote Procedure Call (RPC) RPC runtime procedures  locate the remote computers  determine which transport mechanisms to use  send requests using local transport software Microsoft Interface Definition Language (MIDL) compiler RPC runtime uses a generic RPC transport provider interface to talk to a transport protocol

28 Distributed Application Environment Remote Procedure Call (RPC) Conforms to the RPC standard defined by the Open Software Foundation (OSF) in its distributed computing environment (DCE) specification

29 Distributed Application Environment Named Pipes Implemented in Windows NT by the Named pipe file system driver Named pipes, like files, are represented as file objects in Windows NT and operates under the same security mechanisms as other NT executive objects Operates on an I/O-centered model for sending streams of data from one process to another

30 Distributed Application Environment Client-Side Named Pipe Processing Fig 9-18

31 Corporation-Wide Networking And Distributed Security Windows NT stores account names and passwords in a database called the Security Accounts Manager (SAM) database Network Domains Trust Relationship/Trusted Domain Relationship

32 Corporation-Wide Networking And Distributed Security Fig 9-19

33 Corporation-Wide Networking And Distributed Security Fig 9-20

34 Corporation-Wide Networking And Distributed Security Fig 9-21