Windows NT server and workstation
Name: Li Shen
Course: COSC 541
Date: March, 2002
Instructor: Prof. Mort Anvari
; Introducing Windows NT
No one can deny that Microsoft's Windows family of products has changed the course of computing. Without the existence of graphical user interfaces (GUI), Microsoft Windows would never have been conceived. However, it is definitely to Microsoft's (and Bill Gate's) credit that Windows has survived a very unstable childhood and grown into the incredibly robust and stable operating system called Windows NT.
o What is Windows NT
In 1988 Bill Gates commissioned the creation of a new operating system. The premise for the design of this new operating system was portability, security, compliance and compatibility, scalability, extensibility, and ease of internationalization.
Table 1. Foundation of Windows NT
Portability The system would need to run on different hardware platforms
with minimal changes.
Security It could be locked down through software, meeting NSA's C2-
Compliance and It would be POSIX-compliant, run existing Windows
compatibility applications, and support open international standards.
Scalability It would support symmetric multiprocessing (SMP).
Extensibility It could be easily expanded on by writing to a well-defined
application programming interface (API).
Ease of It could easily be ported to run in numerous different
internationalization languages and writing systems, with minimal modifications to
o Evolution of Windows NT
Perhaps one of the greatest accomplishments for Windows NT was to get rid of DOS completely. Windows NT contains no DOS code in the operating system. Everything is done through emulation of standard DOS calls. Although there is no DOS, Windows NT is still able to run the vast majority of DOS programs as long as they don't try to directly access the hardware or require special device drivers.
The original version of Windows NT was called 3.1, which indicated its relationship to the Windows 3.1 user interface and its capability to run many Windows 3.1 programs. The internals of Windows NT were written from scratch and centered around a microkernel -style architecture similar to UNIX. This microkernel gave Windows NT preemptive multitasking. Additionally, Windows NT made use of process threads to
support symmetric multiprocessing.
Microkernel is the foundation. There are a number of features and services, including an integrated security subsystem, an abstracted, virtualized hardware interface, robust multiprotocol network support, fault tolerance, integrated GUI management tools, and much more.
When NT was finally released, Microsoft came to market with two different versions, Windows NT 3.1 and Windows NT Advanced Server 3.1. While these two products represented a tremendous achievement, their lack of compatibility with existing Windows programs and their steep hardware requirements prevented them from making significant in-roads in the network operating system environment.
Microsoft released NT 3.5’s releasing incorporated a number of important changes and enhancements, such as multiprotocol remote access services using the point-to-point protocol (PPP), a reduced memory footprint, extensive bug fixes, a rewritten TCP/IP stack, and much more. Additionally, Microsoft renamed the products to Windows NT Workstation and Windows NT Server, which, coupled with a further optimization of the internal architectures, helped to better define the exact role of each product. Now with the 4.0 release of NT, Microsoft has made a concerted effort to make Windows NT the standard by which all others are judged. NT Server 4.0 includes not only the Windows 95 user interface, but a host of other features, such as Network OLE, Internet Information Server (IIS) 2.0, RAS multilink and RAS autodial, Point-to-Point Tunneling Protocol (PPTP), fully integrated DNS and WINS, integrated multiprotocol router, expanded driver support, improved performance, and much more.
; Design Objectives of Windows NT Server
There was a definite set of goals in mind when Microsoft began developing Windows NT. These goals played a fundamental role in making NT the product today, and no discussion of Windows NT could be complete without addressing them.
o Client/Server Operating System
User programs, for example, would usually be the clients. They would request services from the protected subsystems, which in this case would be the servers. The protected subsystem would in turn play the part of a client and request services from other parts of the system.
o Flat, 32-bit Memory Model
DOS was designed as a 16-bit operating system. This meant that memory structures could be addressed 16 bits at a time. Windows NT is a 32-bit operating system. It uses 32-bit addresses to access objects. This results in many advantages, one of which is NT's use of a 32-bit flat memory model as opposed to DOS's 16-bit segmented memory model. The 32-bit flat memory model enables NT to address 4,194,304KB (four gigabytes) of memory.
o Reliability Through Protected Memory Model
In Windows NT's memory model all processes get their own 32-bit address space. This 4GB space is divided in half, and the application can only really use the lower 2GB of space. The upper 2GB is for interfacing with other parts of the system. In this way, every process effectively thinks it is the only thing running. There is no way for a process to read or write outside of its own memory space, either accidentally, or intentionally. This has two very positive results. First, it prevents ninety percent of the system crashes that occurred in Windows 3.x. Second, it provides security for each process. o Preemptive Multitasking
There are two major types of operating system multitasking: cooperative and preemptive. The most common form on personal computers is cooperative multitasking, which is used by Windows 3.x and Apple's Mac OS.
The most common foundation for preemptive multitasking is a micro-kernel design, such as Windows NT and UNIX. With preemptive multitasking, the micro-kernel always maintains control of the system. It gives processes specific slices of time in which to run. At the end of that allotted time, the micro-kernel preempts the running process, and
passes control to the next process.
Intel has spent lots of money and come up with some very creative chip designs to prove the nay-sayers wrong and help keep the x86 family alive. The Pentium Pro processor is just the latest example of their ingenuity. However, ultimately, as the programs themselves become more and more portable, the need for hardware compatibility with the older architecture diminishes.
The ultimate design, then, would be a portable operating system which could be quickly and easily moved to new chip architectures as they became available. Recognizing the importance of this, and hedging their bets about the future of the Intel x86 microprocessor family, Microsoft made portability one of the original design goals in Windows NT.
As it relates to Windows NT, scalability is used to refer to NT's capability to take full advantage of multiple processors in a single system. The key to scalability in Windows NT is symmetric multiprocessing (SMP). The SMP design in Windows NT Server enables you to run it on system with from 1 to 32 processors with up to four gigabytes of memory. NT dynamically assigns system and application threads for execution on different processors. The internal operations of Windows NT are designed to take full advantage of SMP systems.
Scalability, however, is not limited by the design of the operating system alone. Both the application software and hardware play a key role in determining the benefits of SMP. If an application is not designed to make effective use of the SMP environment, you might not gain worthwhile performance improvements by using SMP hardware. Likewise, the quality of the SMP hardware can greatly affect the performance of your system. o Personality/Compatibility
Personality is the key to compatibility. Most operating systems, such as DOS, are limited to a single personality. DOS can only run DOS programs. However, Windows NT was designed to support multiple simultaneous personalities. When Microsoft first began working on NT, they planned that it would support the OS/2 Presentation Manager interface as its primary personality. However, as the project continued, and the success of Windows grew, the Windows interface became the primary personality. In addition, Windows NT supports a POSIX personality, an OS/2 personality, and a DOS/Windows personality. Additional personalities, such as a full UNIX personality can easily be added. o Localization
Microsoft recognizes the value and importance of products that integrate into the global marketplace. Windows NT is available in localized versions for Brazilian, Chinese, Danish, Dutch, Finnish, French, German, Italian, Japanese, Korean, Norwegian, Portuguese, Russian, Spanish, and Swedish. In each of these versions, Microsoft has taken efforts to ensure that NT not only communicates in the particular language, but also employs standard idiom, uses correct punctuation in lists, dates, time, and numerical and currency output.
To enforce system security, NT has a robust security model that permeates every level of the operating system. This is unlike the flimsy security provided on other operating systems (including Windows 95), which is merely an easily broken wrapper on top of the operating system.
In order for Windows NT to be accepted as an enterprise workstation and server product, it was important to enable it to gracefully handle abnormal conditions. This is the essence
of fault-tolerance. Windows NT has many features that provide varying levels of fault-tolerance for the system. Included in NT's list of fault-tolerant features are NT's journal-based, recoverable file system (NTFS), disk mirroring and disk stripping with parity (RAID 1 and RAID 5), disk sector sparing, and support for an uninterruptible power supply (UPS).
; Network Operating Systems
Windows NT is both an operating system and a network operating system. With LAN Manager, OS/2 was the operating system and LAN Manager was the network operating system. This integration of the OS and the NOS has proved to be a formidable combination in Windows NT.
o What is a Network Operating System?
A network operating system has traditionally been a method for describing the methods and protocols used by network clients when communicating with a network server. The most common transactions involved here are file and print services. This is a very simplified description, but it demonstrates the typical mentality used when designing these systems. Effectively, the NOS is centered at the server or servers. Most of Microsoft's network-related products have obscured the line between operating system and network operating system. Windows NT is definitely no exception to this. ; Windows NT Workstation Versus Windows NT
Windows NT Workstation was designed as a robust, 32-bit multithreaded, multitasking operating system that was capable of running high-end engineering or mission-critical client/server applications.
Windows NT Server became the cornerstone of Microsoft’s enterprise-class network
operating system. Windows NT Server was designed to provide file, print, and application services to diverse clients.
Features Common to both Windows NT Server and Windows NT
Windows NT Workstation and Windows NT Server are both built using the same core technologies, resulting in products with more similarities than differences. Some of the features common to both Windows NT products are
; High-performance client/server platform
; Network foundation
; GUI management tools
; NetWare integration
; Robust TCP/IP services
; Remote access service
; Integrated C2-level security
; Built-in backup
; Advanced file systems
o High-performance Client/Server Platform
The Windows NT platform was designed to provide a powerful operating system platform capable of scaling from the simplest file and print services network, to the largest enterprise network providing file and print services to thousands of users, as well as advanced messaging and application services.
o Network Foundation
The core networking components are virtually identical between NT Server and NT Workstation. Networking was built into the Windows NT from the beginning; it is one of the fundamental elements of the NT architecture.
Both NT Server and NT Workstation provide standard TCP/IP utilities, including Telnet and FTP clients. Additionally, an FTP Server service can be installed to provide TCP/IP-based file transfer between NT and UNIX hosts or any other system with an FTP client. o GUI Management Tools
Windows NT includes a full set of powerful GUI tools for administering most parts of the operating system. These tools include
1) User Manager: This utility allows you to create and manage user
accounts and groups, as well as user rights, and system-wide password and
2) Server Manager: The Server Manager is a GUI utility used for checking
and controlling many server-related functions of an NT system. It can be
used to check the status, start, pause, or stop services. It can also be used
to obtain a list of currently logged-on users, including what files they have
open. You can also use the Server Manager to send broadcast messages to
3) Disk Manager: Disk Manager is used to create and format disk partitions, as well
as set up advanced disk partitioning, including volume sets, striped sets, and
mirrored sets. This utility is installed on all Windows NT systems and can be used
only to configure local drive systems.
4) Performance Monitor: This is a very powerful application in Windows NT.
Although NT is very good at dynamic performance tuning, it is not able to do
everything on its own. Performance Monitor enables you to graphically view
hundreds of performance counters to ensure that your system is operating at its
peak. You can use Performance Monitor to view the performance counters in real
time, log counters for later reference, or even send administrative alerts or run
external programs when certain thresholds are met. Performance Monitor is
installed on all Windows NT systems.
5) Event Viewer: The Event Viewer enables you to view the system log, application
log and security log. These logs keep you informed of the status of various system
events, and, if you are auditing security-related events, the Event Viewer can be
used to keep track of these as well.
6) RAS Admin: This administrative utility is installed as a component of the
Remote Access Service (RAS), which enables users to use a modem, or other
supported communications device, to connect to the network as a standard
7) DHCP Manager: Use the DHCP Manager program to administer the DHCP
Server service, which enables DHCP-enabled network clients to dynamically
obtain TCP/IP configuration information at startup.
8) WINS Manager: The WINS Manager is used for managing the WINS Server
service, which provides NetBIOS name registration and resolution services on a
o NetWare Integration
Microsoft has gone to great lengths to ensure that Windows NT integrates well with other desktop operating systems and network operating systems. Making both NT Workstation and NT Server fit seamlessly into a NetWare environment was a high priority. o Robust TCP/IP Services
Recognizing the importance of TCP/IP, Microsoft expended great effort to ensure that the TCP/IP implementation in Windows NT was robust and as fast as possible. The results are a highly optimized, 32-bit stack, the core of which is similar in its Windows for Workgroups 3.11, Windows 95, and Windows NT implementations. In addition to focusing on the speed of the stack, Microsoft has tried to provide TCP/IP-based services to make the stack more functional.
o Remote Access Service
The Remote Access Service (RAS) in Windows NT is a very robust tool for creating WAN connections to support today’s advanced client/server computing environments. RAS enables remote users to gain dialin access to the network using the NetBEUI, IPX, or TCP/IP protocols. RAS uses the point-to-point protocol (PPP) to support network connections over standard modems, ISDN, and X.25 WAN links.
RAS is fully integrated with the NT security database so that users can use their standard NT user account and password for authentication. If a greater degree of security is necessary, RAS can take advantage of third-party security hosts.
o Integrated C2-Level Security
When Microsoft designed Windows NT, they concentrated on making it secure. Because NT was intended for use in enterprise environments, it was vital that NT be able to prevent unauthorized access to business-critical information. Microsoft deemed that designing the system to meet and exceed the U.S. National Security Agency’s criteria for C2-level secure systems would result in a product that would satisfy the needs of the commercial sector as well. Additionally, by going through the lengthy C2 certification procedure, Microsoft would have a certifiable security metric that could be used to demonstrate the security of their system.
o Built-In Backup
Security is important for protecting data from accidental or intentional mishandling; however, regular backups are important for protecting your data from other kinds of problems. Recognizing this, Microsoft includes a full-featured, graphical tape backup utility with Windows NT. This utility, called NT Backup, was made for Microsoft by Arcada Software and is very similar to Arcada’s commercial software package, Backup
NT Backup can take advantage of any tape device supported by Windows NT. It can perform typical backup operations, including normal, copy, incremental, differential, and daily. With NT Backup you can have a backup set span multiple tapes, or include multiple backup sets on one tape.
o Advanced File Systems
Windows NT supports two major files systems:
; NT File System (NTFS)
; File Allocation Table (FAT)
To build a truly robust operating system, you must make sure that all components of the system are up to the task. So when designing Windows NT, Microsoft’s engineers chose to develop a new file system that fit in line with NT’s goals: performance, stability, scalability, and reliability. The result was NTFS.
NTFS is an advanced file system that uses journaling—a concept similar to logging— to
provide recoverability. In face, the transaction-processing concepts used in NTFS combined with its relational database model, make NTFS look more like a high-
performance database than a traditional file system. To provide improved speed, NTFS was built on a "lazy-write" model, rather than the "careful-write" model that is used by the traditional FAT file system.
NTFS is the only file system in Windows NT that supports file-level security permissions. This is done through an access control list (ACL), which contains the details of exactly what users are granted permissions to a resource and what level of permissions they have been granted.
In addition, NTFS supports many other advanced features including:
; Long filename support
; Support for software-level sector sparing for fault tolerance
; Support for international filenames through the use of Unicode
; File-level compression through the use of an attribute bit
; Support for multiple data forks in a file, which is necessary for supporting
Windows NT supports FAT primarily to provide backward compatibility. However, the FAT implementation in NT differs somewhat from the implementation in DOS. One difference is that Windows NT allows for long filenames—up to 255 characters.
There are many disadvantages of using FAT under NT. For example, FAT does not give you the recoverability provided by NTFS. Additionally, FAT does not support ACLs, so you cannot assign security permissions to individual files or directories. There are times in NT where you must use the FAT file system. For instance FAT is the only file system support on floppy drives. Also, because of their design, the boot partition on RISC computers running NT must be FAT.
There are some things in FAT’s favor though. Because of overhead involved in keeping the journal log under NTFS, there are situations in which FAT might be faster for writing information.
; Windows NT networking
Windows NT has taken networking to heart and built networking in as an integrated part of the operating system. You still have a choice on drivers and services, but there is a standard interface between the operating system and the network that all vendors are writing to. Also, because Windows NT is a 32-bit operating system that supports better memory management and multitasking, it is much easier to implement network drivers and services. This is especially true of those network services such as FTP servers, which have to continuously monitor the network in background to see if there are any requests for information from other computers on the network.