implementing an infrastructure framework

by John Holmwood
<[email protected]>

John Holmwood is an infrastructure architect at NOVA Gas Transmission Ltd. He has been a member of the Calgary UNIX User's Group since 1991 serving on its board of directors from 1992 through 1994. This is his first year as a USENIX member.

From 1995 until 1997, NOVA Gas Transmission Ltd. (NGTL), a natural gas transmission utility, attempted to build a service-based corporate-distributed computing infrastructure based on Open System Standards. By 1997, they admitted that the attempt had failed. NGTL's information technology group is divided into multiple departments, each responsible for a specific aspect of the computing infrastructure. Each department selected the best products within the restrictions of Open System Standards that met its specific business needs. Unfortunately, the products could not be combined to provide an integrated infrastructure that supported the business.

NGTL Environments

NGTL is the natural gas transmission provider within the province of Alberta, Canada. Physically, its computing infrastructure is made up of a head office in Calgary, Alberta, five regional centers connected to Calgary by a frame relay wide area network, and 11 field offices connected to the regional centers by 56KB wide area networks. The company has 3,000 employees, 2,000 at the Calgary site and the rest spread around the province at the field offices and regional centers. Each employee has a workstation that will be running Microsoft NT by the end of 1997. The Calgary site has a data center where the majority of the company's servers are located. It contains a mainframe and approximately 120 UNIX servers from a variety of vendors. Each regional center and field office will contain Windows NT servers to support the workstations.

NGTL's computing infrastructure is made up of two environments: a desktop environment, and a distributed computing environment. Figure 1 shows this infrastructure with the support services.

What's Wrong with Standards

Unfortunately, specifying the standards to which the support services must conform does not ensure that products can be combined to form an integrated framework. This is because standards don't normally define everything about a product. Each company producing a product believes that it must be able to distinguish its product from its competitors.

Consider the PC hardware market. Because the hardware is essentially defined by standards, formal or de facto, the manufacturers must compete with price and quality as the distinguishing characteristics between products. Vendors in other areas of the computing industry do not want to be in this position. Therefore, although the standards define how the various components should interact, each product is slightly different, and products from different vendors will not interface seamlessly. The purchaser is left with the task of making the products work together to provide a consistent infrastructure.

One solution to this problem is to minimize the number of vendors from whom you purchase products. In the ideal world, you could get all of the products you need from one vendor. In fact, this is exactly what each vendor promises. NGTL approached the two vendors with whom it does the most business and asked them to describe their support services framework and how they could provide the services NGTL needed.

Figure 1: NGTL Infrastructure

Microsoft's Framework

Microsoft holds the dominant position in desktop computing. Its roots are in the personal computing world. In recent years, it has been expanding into enterprise computing; however, its background has resulted in its approaching the enterprise computing space from the point of view of someone using a desktop computer and asking what services are required to support this desktop.

Microsoft's marketing strategy is reminiscent of IBM's strategy of the early 1980s. It produces an integrated line of services that can support small- to medium-sized enterprises. (See <http://www.microsoft.com/vbasic/docs/buscomp.htm>.) The services work very well in a Microsoft-only environment. Part of its strategy appears to be to provide functionality only by combining multiple Microsoft services. Examples of this include the need to deploy SQL Server in order to use SMS or the need for Exchange in order to utilize the workgroup features of Outlook. One result of this portion of Microsoft's strategy is that once Microsoft products get a foothold in your organization, the need for additional Microsoft products seems to proliferate.

For companies with a heterogeneous computing infrastructure, Microsoft's strategy results in either duplicate support services, one set for Microsoft products and a second set for everything else, or a custom interface between the Microsoft products and everything else.

IBM's Framework

IBM is a major player in the enterprise computing environment, particularly with large organizations (those with 1,000 or more users). It approaches the enterprise computing space from the viewpoint of servers and the services they provide. With the Open Blueprint architecture (See <http://www.software.ibm.com/openblue>), IBM has embraced the Open System Standards model for enterprise computing. As could be expected, IBM provides products for almost all of the components in its Open Blueprint. Where IBM doesn't have a product, it specifies third-party products that work seamlessly within the environment. Furthermore, the IBM products work across a range of operating systems, including not only all of IBM's, but also Microsoft's Windows NT and most of the popular versions of UNIX.

The Open Blueprint architecture provides its seamless integration by layering services on top of the operating systems. For example, it uses The Open Group's DCE as the basis of its distributed computing services. This adds significant cost to the infrastructure. Additionally, it doesn't do a good job of integrating the enterprise computing environment with the desktop computing environment dominated by Microsoft. The Open Blueprint's solution is to use World Wide Web-based technologies: HTML and Java.

What NGTL Is Doing

After reviewing the responses from these vendors, NGTL determined that neither vendor could supply all of the support services required. Figure 2 shows a graphical depiction of NGTL's analysis of the vendors' responses.

An application running on a single computer (whether desktop or mainframe), has more of its support services provided by the operating system than does a distributed application. The result is an ellipse of required support services. As the figure shows, Microsoft provides solutions at the desktop end of the ellipse, and IBM provides solutions at the mainframe end. The section in the middle, where the two frameworks overlap, is where the customer must make choices and develop custom interfaces.

NGTL created an Infrastructure Framework by blending the two vendor frameworks with products already selected for its support services (e.g., Oracle, Entrust, Dazel, etc.). Each vendor's framework addresses one of NGTL's computing environments. The Microsoft framework addresses the desktop environment. The IBM Open Blueprint addresses the distributed computing environment.

Real-World Example

Theory is nice, but to understand how it is being applied, let's look at a real example. NGTL is replacing its mainframe-based groupware system. The system includes email, group scheduling, public folders, and a rudimentary task list. The NGTL framework indicates that the desktop portion of the new system must fit into the Microsoft framework. NGTL has chosen Microsoft Outlook for this component. It integrates smoothly with the productivity applications in the desktop environment and uses the Microsoft protocols for interprocess communications to interact with other applications on the desktop computer. The framework indicates that the messaging backbone that Outlook attaches to should fit into the IBM Open Blueprint framework. This is where problems arise. In order to provide the functionality of the system being replaced, Outlook requires Microsoft Exchange as its messaging backbone. With any other messaging backbone product, Outlook can act only as a personal rather than group scheduler and cannot provide the public folder functions.

Figure 2: NGTL Framework

Bowing to the inevitable, NGTL is deploying Exchange as its messaging backbone. However, it is being deployed in a manner consistent with the IBM Open Blueprint environment. Each Exchange server is being equipped with the Exchange Internet Gateway product. This allows all other applications and services to access the backbone using the IETF SMTP protocol specified by the IBM framework. Each employee's mail address is specified using the SMTP rather than the X.400 protocol. Internally, Exchange uses the X.400 protocol, but it is hidden away from both the users and the other applications and services.

Messaging is the first and probably simplest integration effort that NGTL has undertaken. Integrating Windows NT into a distributed environment based upon the Open Group's DCE and DFS will be a larger challenge.