## Interoperability and Enterprise Integration With Windows NT Desktops

### Peter J. Auditore

Hummingbird Communications Inc.
Mountain View, CA 94040
Phone: 650-917-7300
Fax: 650-917-7309
Email: petera@cali.hcl.com
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Contents

Introduction

Windows NT and UNIX Realities

Windows NT to Enterprise Enabling Technologies

Windows NT Workstation Overview

Windows NT Workstation Issues and Solutions

Windows NT TCP/IP Applications: PC X Servers

Windows NT, OpenGL and GLX

32 Bit TCP/IP Applications And NFS For Windows NT

The Network File System

Windows NT Server Overview

Windows NT Server Integration Issues and Solutions

Windows NT Administration And The Inet Daemon Server Suite

Migrating UNIX Applications To The Windows NT Platform

Summary

Introduction

Microsoft’s Windows NT workstation and server platforms have rapidly evolved to become robust and stable business computing solutions for the 90’s and beyond. The awesome computing power of today's personal computer desktop, combined with Microsoft's Windows NT, blurs the line between what has been traditionally considered a personal computer and a workstation. Windows NT has rapidly become today’s choice for an enterprise workstation, as well as an important workgroup server platform. Windows NT is like a tsunami, and never before has the computer industry witnessed such rapid adoption of a new technology platform. However, the success of Windows NT has created a great deal of chaos and confusion, particularly in the MultiFinder enterprise marketplace. This has presented a major challenge to network managers and administrators who are integrating Windows NT within the multivendor enterprise internetwork.

Many of the foundation technologies that enable cross platform integration in multivendor enterprise environments were developed by the UNIX community. Successful coexistence of Windows NT systems in the enterprise internetwork is dependent on the implementation of this rich suite of communication technologies. The technologies of the Web were also developed by the "open systems" UNIX community, but although they are operating system and platform independent, at this time they offer limited functionality to enterprise systems managers seeking solutions for integrating Windows NT and legacy systems.

Because today’s enterprise internetwork is multivendor, interoperability—the ability to share information between different computer systems—has become a critical requirement for internetworking software. Interoperability is a major issue with Windows NT, and many network managers have been faced with the stark reality that when an NT node is added to the network it only sees other Microsoft nodes, i.e. Netbeui. Compounding this issue is NT’s limited support for DNS, and the overall lack of TCP/IP utilities and applications. For example there is no support for one of the world’s most powerful and successful multi-vendor internetwork connectivity technologies, the X Window System. The X Window System’s ability to connect to many different types of computers has made it one of the most powerful Windows NT and UNIX integration technologies. To address many Windows NT and UNIX integration issues, organizations have turned to third party vendors of open system standards-based software technologies such as NIS, DNS, TCP/IP applications, and other internetworking software to enable access to enterprise-wide information and applications.

The NT-UNIX comparison has created a great deal of controversy, discussion, and press coverage over the past several years. The UNIX camp would argue that UNIX has a major advantage by being a more mature operating system that supports open systems standards, distributed networking, and has a scaleable architecture. The Windows NT camp touts NT as having easier installation and administration, a familiar and easy-to-use interface, support for a large number of Microsoft Windows applications, and the ability to run on inexpensive PC platforms and microprocessors such as the Intel Pentium. Undoubtedly, the benefits and advantages of each platform will vary depending on their implementation and use as a workstation or server.

Windows NT and UNIX Realities

Until Windows NT achieves the robustness, scalability, clustering, 64-bit processing, and multi-user capabilities of UNIX, it will have limited impact on enterprise UNIX servers that currently deliver mission critical information and applications to enterprise desktops. Organizations have invested billions over the past ten years in developing mission-critical applications on the UNIX-based enterprise servers that now run their businesses. According to International Data Corporation, (IDC) currently 80% of all enterprise servers are UNIX based, and the implementation of UNIX-based enterprise servers is expected to grow at a CAGR of 20% over the next several years. The immediate impact of Windows NT has been primarily on UNIX desktops and workgroup file, print and application servers, not UNIX enterprise servers. Widespread deployment of Windows NT servers, primarily as workgroup servers, is underway and many organizations are implementing Windows NT desktops and controlling application access through NT servers.

The objective of this white paper is to provide a general overview of the internetworking technologies available for integrating Windows NT and enterprise computer systems. Our focus is not to compare and contrast the UNIX and Windows NT platforms. The vendor-neutral discussion focuses on solving Windows NT and multi-vendor enterprise integration issues from a workstation and server perspective, and does not engage in the vaporware hyperbole that is often associated with Windows platforms.

Windows NT to Enterprise Enabling Technologies

Windows NT represents a huge business opportunity for internetworking software vendors, as well as UNIX software developers willing to port UNIX applications to the Windows NT platform. A wide variety of enhanced internetwork connectivity products have emerged from third party suppliers, including support for IBM-SNA integration, Internet Browsers, Web servers, NFS clients and servers, PC X servers and OpenGL-GLX. However, most Windows NT third-party internetwork connectivity solutions have been pioneered on UNIX workstations, and internetworking the Windows NT desktop essentially means adding various components of UNIX-based internetworking standards. Interoperability—the ability to share resources and interoperate with heterogeneous computer systems—is perhaps one of Windows NT’s greatest weaknesses. Although the Windows NT workstation and server operating systems have integrated TCP/IP, and now feature robust Web technology integration, aside from NetWare integration utilities they have not been designed to be easily integrated into open systems-based heterogeneous enterprise environments.

The hallmark of the UNIX platform is a highly functional and agreed upon set of open standards enabling interoperability. Third party software vendors have rapidly developed a rich array of integration technologies based on these open industry internetworking standards. There are products available today that provide Windows NT with full POSIX compliance, UNIX shells, UNIX to NT application porting and development tools, TCP/IP application suites, DNS for the Windows NT workstation and server, and even 3-D capable PC X servers. Interestingly, these third party enabling technologies essentially UNIXize the Windows NT platform and address the following areas.

Windows NT and Enterprise Integration Coexistence Areas

- Foundation Communication & Integration Technologies

- TCP/IP—a rich routable protocol suite enabling LAN-WAN-GAN connectivity and information access, the backbone of the Internet.
- Networking and graphical APIs.
- Third Party DNS, UNIX Shell and POSIX compliance.
- World Wide Web technologies, HTTP, HTML and Java.

- Legacy Application and Data Base Access With Emulation Technologies
- Legacy emulation, VT52-VT420, HP 3000-9000.
- TN3270 & TN5250 IBM mainframe and minicomputer emulation
- PC X Windows emulation.
- Microsoft Hydra & Citrix WinFrame (ICA protocol) and (X Windows protocol).

Windows NT and Enterprise Integration Coexistence Areas Continued

- Migration of UNIX Applications to Window NT

- Porting of UNIX applications to NT as native Windows NT applications.
- Porting of UNIX applications to NT as UNIX character applications—maintain UNIX interconnectivity.
- Porting of UNIX applications to NT as X Windows/UNIX application—maintaining X Windows interconnectivity and interclient communications.

- File System Integration

- Implementation of the Network File System clients and servers.
- Implementation of NFS gateway.
- Implementation of SMB server on UNIX (Samba)
- Implementation of UNIX lpr, lpd and lpq.
- Implementation of DCE’s Distributed File System.

- System Management

- Windows NT server DHCP support and Workstation Bootp support
- Implementation of UNIX Inet daemon suite.
- Integration with the Network Information System (NIS).
- Future integration with the Lightweight Directory Access Protocol, (LDAP).

Windows NT can present some significant limitations for organizations integrating Windows NT servers and workstations, especially regarding the assignment of IP addresses, control of networked peripherals, and support for NIS and DNS. For example the Windows Internet Naming Service (WINS) doesn’t recognize UNIX workstations and servers and doesn’t interoperate well with the Domain Naming Service (DNS). A WINS server is a central database that essentially maps NetBIOS names to TCP/IP addresses. If you are integrating Windows NT workstations and servers with UNIX platforms you may need to implement WINS/DNS gateway support, and/or coordinate both DHCP/WINS and some other solution such as DNS or DHCP/DDNS (Dynamic Domain Naming Service). There are several third-party DNS solutions that are easily implemented and reportedly address most of these issues. However, Microsoft recently added Windows NT Internet Information Server version 4.0, which includes a DNS name server, that can be installed, but not configured, through the Network Control Panel.

The Windows NT Workstation

Windows NT Workstation has been wildly successful, and is now the defacto standard enterprise desktop. As an enterprise desktop solution, the Windows NT-Intel Pentium desktop has an attractive price performance advantage over traditional UNIX workstation desktops. The initial cost of implementing Windows NT-Intel Pentium desktops is significantly less than a UNIX workstation, and the overall cost of ownership (management and administration) is considered to be significantly less. Ultimately, NT applications following the PC model will undoubtedly be less expensive than the current suite of UNIX applications. Additionally, Windows NT has advanced security and administrative capabilities, a consistent user interface between Windows 95 and Windows NT, and enables organizations to leverage their legacy MS-DOS and Windows applications. From an organizational perspective, these are very compelling reasons to implement Windows NT desktops.

Brief Overview of Windows NT Enhancements & Features

- Robust and stable multithreaded 32-bit operating system
- Preemptive multitasking
- Enhanced hardware compatibility (Intel, Alpha, and Intel IA 64)
- The ability to multitask 16-bit MS-DOS and Windows applications on the desktop
- Support for all major network clients and protocols
- Support for SNMP-based network managers (Openview, Polycenter, Unicenter, Netview)
- Support for ISAPI, Java and Active X
- Support for Object-Oriented managers (Tivoli, Novadigm and future OLE)
- DMTF inventory management and software distribution (Systems Management Server)
- Built-in enterprise-wide networking capabilities include:

- IPX
- NetBEUI
- Scaleable TCP/IP
- Support for DHCP, easing management of large TCP/IP networks
- Support for interoperable messaging: SMTP, PROFs, X.400, etc.
- Web browser and IIS HTTP server and MFC ISAPI extensions

- Multiprotocol routing—packet routing between IP, Novell NetWare IPX and NetBIOS networks.
- Support for OpenGLÔ enabling 3-D applications to be developed, ported, run and/or accessed from the NT desktop with the use of third-party solutions and natively.

The following table details some of the most common issues encountered by information managers, and most have been addressed by third party software developers.

Windows NT Workstation Integration Issues and Solutions

Integration Issue | Solution
Access character-based UNIX applications from the NT Desktop. | Implement third-party terminal emulation software on the Windows NT desktop.
Access graphical UNIX applications from NT desktop. | Implement third-party PC X server software on the Windows NT desktop.
Access legacy IBM applications from the NT desktop. | Implement third-party IBM TN3270 &TN5250 emulation software on the NT desktop.
Access files resident on UNIX Network File System servers from NT desktops. | Implement third-party NFS client software on the Windows NT desktop, or NFS gateway.
Share files between NT servers and UNIX servers. | Implement NFS server software on Windows NT servers.
Run UNIX applications on Windows NT servers. | Port UNIX application to Windows NT with X Window System development tools.
Distribute Windows NT applications and Microsoft Windows applications over the organizational Internetwork | Implement Microsoft Hydra, or third-party encapsulation and server distribution technologies on Windows NT servers.
Access 3-D applications from network computers on Windows NT workstations | Implement GLX X Windows extension on the NT workstation along with X server software.
Remotely access UNIX applications via serial and/or telephone lines. | Implement Broadway (X11R6.3) and LBX for high performance remote access.
Control access to network-based peripherals and such as high quality printers and plotters | Turn off Microsoft networking and utilize only TCP/IP based file and print services.
Integrate Windows NT Workstations and Desktops into the Internetwork. | Implement TCP/IP and WINS/DNS gateway on the Windows NT workstation and server.

Windows NT TCP/IP Applications: PC X Server Software

PC X server software is perhaps one of the most powerful integration technologies available to Windows NT users. PC X servers enable NT users to access and display UNIX, VMS, Ultrix and supercomputer applications in windows on the NT desktop. Many early adopters of PC X server technology are migrating to Windows NT and are cashing in on the enormous performance increase and functionality of native 32-bit PC X servers. A number of third party software suppliers offer PC X server products marketed as being optimized for Windows NT. These products do not run as native Windows NT applications (usually they are 32 bit Windows applications) and have limited ability to harness the enhanced functionality and performance features of NT, such as multi-threading. This significantly reduces their overall functionality and reduces their performance.

Multithreading And Preemptive Multitasking

NT’s preemptive multitasking architecture enables native applications to harness multi-threading, significantly improving overall PC X server performance. In contrast to Windows’ non-preemptive multitasking, in which a thread can use the processor as long as it requires, NT’s preemptive multitasking enables the operating system to control multitasking. Windows NT can suspend and/or interrupt a thread if a thread with higher priority emerges. This results in more efficient multitasking thread execution, as well as a more stable operating system. Performance improvements for PC X servers (and all native NT applications) are realized when threads are executed concurrently, enabling multiple threads to work on a single process.

Windows NT Workstation Benefits For PC X Servers

- Stable and robust 32-bit operating system.
- Preemptive multitasking architecture.
- Multithreading at the network layer increases network application performance.
- Integrated TCP/IP.
- Dramatically increased overall X Server performance.
- The end of the 640K RAM DOS memory limitation.
- Multiple protocol stacks can be employed and run concurrently on the NT desktop for enterprise connectivity, including TCP/IP, IPX/SPX, Banyan Vines etc.
- Virtual memory—each application runs in a separate address space.
- Built-in administrative and diagnostic features.
- Monitors 320 workstation statistics: memory, cache and processor.
- Remote access to UNIX applications via serial, telephone and ISDN lines.

Windows NT Workstation, OpenGLÔ And GLX Extension

Windows NT includes native support for Silicon Graphics OpenGL, which allows 3-D applications to be run locally on the NT workstation, allowing the viewing of still and animated 3-D images. Support for OpenGL and the implementation of a third party OpenGL-GLX-X Windows extension enables high powered Silicon Graphics (SGI) and supercomputer-based 3-D applications to be accessed and viewed on the Windows NT desktop. This allows enterprises to leverage their investment in costly 3-D hardware and software by distributing compute intensive 3-D applications over the enterprise internetwork. Powerful 3-D data mining and visualization tools available in applications such as SGI’s MineSetÔ , can now be accessed by Windows NT.

32-Bit TCP/IP Application Suites and NFS for Windows NT

The TCP/IP protocol suite and its associated open industry standards such as the X Window and Network File systems, have become key enabling technologies facilitating the integration of Windows NT and UNIX Systems in enterprise computing environments. Although Microsoft has integrated the TCP/IP stack in Windows 95 and Windows NT operating systems, they have not included many of the TCP/IP applications that networked enterprise desktops require.

Microsoft’s rapid adoption and integration WWW technologies into both NT workstation and desktop has been a major impetus, but NT’s support for the interoperable technologies of today’s enterprise internetwork remains limited. Beyond the basic TCP/IP stack, and NT to Netware integration, Microsoft has included only rudimentary FTP and Telnet clients and most recently a FTPd and Telentd daemons in the latest NT resource kit, and also accessible in the network software section of NT’s control panel.

Third-party NFS products and 32-bit TCP/IP application suites for Windows NT workstation and server have been in development for several years and are now robust stable products. Several vendors offer NFS clients for Windows NT that include a full suite of 32-bit client and server TCP/IP applications. TCP\IP application suites can be organized into four segments as depicted in the bullet chart on the next page. The addition of a third party TCP/IP application suite can significantly bolster the desktop and administrative functionality of both Windows NT server and workstations.

Third-Party TCP/IP Application Suite For Windows NT

- General applications

- Telnet—remote login protocol or virtual terminal.
- FTP—text and binary file transfer.
- Electronic mail client.
- Network News client—provides access to network news groups.
- Internet Relay Chat (IRC) client.
- Web browser—provides access to web servers and usually supports the gopher protocol.

- Diagnostic tools

- Finger—provides information on which users are active on a server.
- Ping—determines whether a computer is connected to the network.
- Traceroute—traces the path of data packets across networks, and is especially useful for troubleshooting routing difficulties.
- NSLookup—name service lookup for a specific computer or network domain, can also be used for DNS queries.

- Administrative utilities

- Inet daemon—adds UNIX server suite functionality to NT workstation and server.
- Cookie—utility to return a quotation.
- DHCP—enables dynamic IP addressing.
- UNIX "R"commands—enable users to run commands from Windows NT for quick and easy access to remote network computers.
- Talk—utility that communicates between computers over the network.
- Exports—displays remote NFS file systems available for mounting.
- Wiki—Paging utility enables messages to be sent directly to a paging system.
- Rpcinfo—list remote procedure call processes running on a remote server.
- Whois—query utility enables lookup of users from network data base.
- TAR Backup utility—allows users to easily transfer entire directories and their contents to an archive file.
- Basic scripting language—with APIs for FTP and Telnet, providing mechanism for sophisticated application development and task automation.

- Advanced applications

- Network File System client—access to NFS file servers, CD-ROM drives and network printers.
- PC X server—connectivity to graphical X Windows based UNIX applications.
- TN3270 client—IBM 3090 connectivity.
- TN5250 client—IBM AS400 connectivity.
- Terminal emulation—providing VT320, VT340, HP, Wyse, SCO ANSI connectivity.

The Network File System

Why NFS for Windows NT? File system interoperability. The Windows NT and Windows 95 file systems support a wide variety of file systems such as FAT, VFAT, NTFS, HPFS and CDFS, and are compatible with a wide range of PC networking products that are primarily designed for small workgroup LANs. However, Windows NTFS has not been designed to interoperate with different computer platforms and file systems, and is not well suited for integration into large multivendor enterprise computing environments. NFS is an established open standard for interoperable file services in many enterprise environments.

The Windows NT server platform is well suited to functioning as an NFS server. NT’s integrated TCP/IP facilitates NFS network communications, and NT’s high performance 32-bit multithreaded operating system enables the servicing of multiple file and print services simultaneously. The quality and type of Windows NT, however, can drastically impact NFS functionality, scalability and performance.

Key Third Party NFS Feature and Functionality Enhancements

- Kernel mode implementation vs. user mode
- Implementation as a Windows NT Service
- NFS client tuning option.
- Support for Windows NT NTFS, FAT, HPFS and CDFS
- Support for the Windows NT security system
- Tools for mapping UNIX user/group IDs to NT users and groups
- Support for Symmetric Multiprocessing (SMP)
- Support for NFS Version 3, and WebNFS
- Support for 32-bit file locking
- Support for Universal Naming Convention (UNC)
- Support for Sun Microsystem’s Network Information System (NIS)

High performance NFS products for Windows NT are implemented as a Windows NT service, and are implemented at the kernel level. NT NFS implementations that execute, or load in the system kernel space take full advantage of NT’s multithreaded design, and deliver higher performance than user mode implementations. Multithreaded NFS server implementations enable the NFS servers to service the file requests of multiple users concurrently, and support server scalability by taking advantage of symmetric multiprocessing through distribution of file read and write requests to multiple processors.

NFS client and server support for NIS can simplify the management of user names, passwords, host names group and user IDs through the central enterprise NIS databases.

The Windows NT Server

Microsoft is supporting third party middleware solutions that provide Windows NT servers with a multi-user capability that enable Windows and Windows NT applications to be distributed over a network via proprietary protocols. Consistently overlooked, however, is the reality that Windows NT has not been designed to be, or is, a multiuser operating system. This limits Windows NT’s functionality as an enterprise server, and has delegated its role in enterprise computing environments to the workgroup area.

Windows NT is a multi-console operating system that can be kludged to deliver multiuser capability only by adding Windows Terminal Server, Citrix’s WinFrame and ICA protocol, and/or Insignia, and X Windows protocol technology to Windows NT servers. Although this approach provides an excellent means of delivering Windows applications to non-Windows desktops, a multiuser Windows NT implementation requires a significant hardware investment, and a dedicated server with a minimum of 128 MB of RAM per ten users. Presently, the majority of enterprise desktops accessing Windows applications via this approach appear to be non-Windows desktops, UNIX workstation, Macintosh and X terminals.

The Windows NT server’s scalability has also been reported to be limited, and the limited support for symmetrical multiprocessing significantly impacts its success as a direct competitor to UNIX database servers. Windows NT Version 5, a 64 bit, object-oriented server version, is projected to be available in 1999, and will feature global naming services, server clustering and 64-bit application support. A wide spectrum of third party software products significantly enhance the Windows NT server’s functionality and include capabilities such as:

- Provide Windows NT servers with a multiuser capability.
- Enable distribution of Windows NT applications over a network.
- Development of 3-D X Window applications with GLX and Xlib.
- Distribute 3-D applications over the network.
- Add NFS server software for enterprise-wide file system sharing.
- Add UNIX style INET daemon functionality.
- Add UNIX system commands.
- Add UNIX shell capability and full POSIX compliance.

Again, third party software developers have addressed many of the NT server enterprise integration issues; the table below identifies some common integration issues and their solutions

Windows NT Server Integration Issues and Solutions

Integration Issue | Solution
Integrate NT servers with the enterprise internetwork. | Implement WINS/DNS gateway or third-party DNS and NT 4.0 IIS
Enable NT servers to share files with multi-vendor workstations and servers.. | Implement third-party NFS server software, NFS Gateways, or SMB server freeware.
Provide NT servers with a multi-user capability. | Implement Windows Terminal Server, or third-party Citrix based WinFrame and/or Insignia-Tektronix technology.
Distribute NT and Windows applications to other Windows Desktops. | Implement Windows Terminal Server, or third-party Citrix based WinFrame and other multi-user technologies.
Distribute NT and Windows applications to non-Windows desktops UNIX, Macintosh and X terminals.. | Implement Windows Terminal Server, or third-party X Windows encapsulation technology (Insignia, or Tektronix on Windows NT servers.
Run UNIX applications on Windows NT servers. | Port UNIX applications to NT servers with X Window System development tools.
Enhance Windows NT administration and internetwork functionality. | Implement third-party Inet daemon, NFS server and UNIX scripting on Windows NT server.
Control access to network-based peripherals such as high printer and plotters | Turn off Microsoft networking and utilize only TCP/IP based file and print services.
Add UNIX system commands. | Implement third-party system commands.
Add UNIX Shell and POSIX compliance to Windows NT server. | Implement third-party UNIX shell and POSIX functionality.

Windows NT Administration And The Inet Daemon Server Suite

Administration of Window NT workstations and servers has also become a major issue with many network managers. Although Microsoft’s RAS and SMS provide a highly functional suite of services, their administrative functionality is limited when compared with UNIX systems. Many enterprise customers who have implemented Microsoft networking also have been surprised to find that they cannot control Windows users’ access to network-based peripherals such as high-end plotters and printers. To regain control of peripherals, and provide interoperable file and print services, enterprise administrators have implemented third-party TCP/IP application suites that include the NFS.

Enterprise system administrators are addressing some of the administration limitations of Windows NT by implementing the UNIX Inet daemon suite. Some TCP/IP products for Windows NT have been optimized by incorporating several important aspects of UNIX, such as the Inet daemon. The Inet daemon server suite was created to improve the efficiency of UNIX and TCP/IP by reducing the number of processes activated during system startup, many of which are not continuously required.

Inetd (the InterNET service Daemon) continuously runs as an active process waiting for client connection requests. Upon receiving the request, Inetd starts up the appropriate server daemon (telnetd, FTPd, etc), thereby conserving server and/or workstation resources. Complete Inetd server suites are only provided by a few developers of TCP/IP application suites for the Windows NT workstation and server. A full Inet daemon server suite provides the Windows NT platform with the full functionality of a UNIX workstation, enabling the PC desktop or server to provide client/server TCP/IP functions. This facilitates peer-to-peer connectivity among NT workstations and workgroups using TCP/IP applications.

Inetd can provide a valuable management utility enabling network managers and administrators to Telnet into an NT workstation or server, and/or to execute remote operations or scripts. The value and functionality of Inetd is often underestimated and overlooked because it is a background service, and is seamlessly integrated into the UNIX operating system along with the TCP/IP protocol suite.

Inet Daemon - TCP/IP Server Suite And Functions

Finger server Services client inquiries as to who is logged on

FTP server Supports FTP client file transfer

Gopher server Supports gopher client searches and menus

LDP server Supports PC client UNIX Line Printer Requests

New Talk server Supports (New Talk) UNIX chat facility

Bootp server Supports remote TCP/IP configurations

RSH server Supports requests to execute command on a

remote system

Talk server Supports user (Old Talk) UNIX Chat facility

Telnet server Services Telnet client (virtual terminal) sessions

TFTP server Provides file transfer for diskless workstations

Trival name server Services host to IP address translations

(name resolution)

Time server Synchronizes client time with other NFS servers

HTTP server Enables broadcasting of Web pages

Exec Server Provides remote execution services

Login server Provides remote login services

Timed server Provides time of the day

Migrating UNIX and VMS Applications To Windows NT

Many UNIX applications have been ported to the Windows NT platform, and many are on the way as companies begin to take advantage of the opportunities in the emerging NT market, and migrate mission critical applications to the NT platform. A major issue encountered by many developer is NT’s lack of support for networking and graphical API’s such as the X Window system. NT’s support for Silicon Graphic’s OpenGL library and APIs for 3-D graphics, however, enables high-end 3-D applications to be ported from UNIX. Windows NT does not currently include the X Window system, OpenGL’s X Windows extension , GLX, and/or the Motif GUI that are required by graphical UNIX-based applications.

Application porting time is dependent on the application, platform, and the method of porting. There are several approaches to developing and/or porting applications from the UNIX platform to Windows NT, but, each operating system is substantially different and this leads to unavoidable difficulties in mapping system calls . The approaches cited below entail varying degrees of difficulty depending on the type of application ported. However, many developers have found that the complexity of the porting process can be significantly reduced by adding UNIX system calls, libraries and utilities to NT platform.

Application Development and Porting Approaches

- Redevelop UNIX application as a native NT application.
- Port UNIX application as a character-based native NT application.
- Port UNIX application as a character-based NT/UNIX application with UNIX system calls.
- Port UNIX application as a X Windows-based NT application.

In general a well behaved X Windows application (X client) can usually be ported in one day. UNIX applications that are platform specific (HP, IBM, SUN, DEC, SGI) or involve interclient communications significantly complicate the porting process and may require redesign of the application. Several third-party developers offer UNIX & VMS -Windows NT porting and development toolkits, and most include X display server software. However, some vendors employ proprietary APIs. Most of these products support the Microsoft Win32 SDK or Visual C/++ compiler, Borland’s C compiler, and the Watcom C compiler environment.

Summary

Integration of computing technologies into today’s multi-vendor enterprise internetwork is a challenging proposition even for the best network administrators and experts. Windows NT can significantly increase this challenge depending on the nature of the enterprise environment. The heterogeneous nature of current internetwork topology is a reality that is often overlooked by information managers when selecting technology for solving business problems. Integration difficulties are often compounded by vendors who claim to fully support open standards technologies, but really go only part of the way. In contrast to what some might insist, there is no one right or all inclusive technology solution that comprehensively addresses all the issues for every computing environment. Enterprise computing environments are not black and white, and every enterprise computing environment has its own unique requirements and inherent issues, whether it be a desktop, workgroup server, enterprise server, or a middleware environment.

Windows NT is rapidly becoming an important computing platform for many of our customers, and Hummingbird is committed to developing innovative open standards-based technologies that ease the coexistence of Windows NT and the enterprise internetwork. Although the dynamic nature of the computer industry may obsolete some this information before it is published, much of it has been compiled during customer visits. Hummingbird hopes that this white paper will assist you in the decision making and integration processes.