http://www.microsoft.com/BackOffice/reading/deacones.htm (PC Press Internet CD, 03/1996)IBM Internet Journal
Focusing On Internetworking Solutions For IBM Host-Based Enterprises
By Paul Morse
As with any progressive organization, Deaconess Health System Corp. of St. Louis is aggressively pursuing client/server, distributed processing with a fervor. Deaconess has become a major healthcare provider in the St. Louis metropolitan area by defining a comprehensive, multifaceted mission that focuses on high quality, managed primary care with extensive employee participation.
A high rate of growth has resulted in an organization with more than 3,200 employees and $330 million in annual revenues. This rapid growth, led by a definite mission, has created the computing need for a uniform and flexible development and networking environment that can easily accommodate future growth while meeting the needs of current users.
The physical user environment at Deaconess consists of two hospitals, an administration building, a warehouse complex and 24 additional locations comprised of physicians' offices, medical labs, medical centers and clinics. The main buildings - two hospitals, warehouse and administration - are connected with multiple T1 links running the enterprise Ethernet. Remote offices maintain connection with the Ethernet through 384Kb Frame Relay (FR) links.
The remote physicians' offices range from one physician with a PC to offices with 33 physicians and 54 PCs. All these locations employ a variety of networking protocols, such as Novell IPX/SPX, Microsoft NetBEUI, TCP/IP and AppleTalk. The campus computing environment consists of a DEC VAX in both the main laboratory and radiology, a RISC System/6000 (RS/6000) in the phar-macy, an NCR Tower running a home health system and an Intel platform for a MUMPS-based application set.
The Prognosis, Open
"Our mission and computing environment must blend to support our involvement in the evolution of the healthcare model," says Bob Bowman, CIO for Deaconess. To that end, Deaconess is in the process of rightsizing from an AT&T GIS (NCR) mainframe and has enlisted a service provider that offers a CICS-based Hospital Information System on an IBM/370 architecture MVS/ESA mainframe in another state. Due to the rightsizing, providing 3270 access to the mainframe applications by a rapidly growing number of end users was the initial challenge faced by I/S. Several solutions for providing 3270 access to the remote mainframe were considered.
The ultimate solution would be required to support the mission and be able to accommodate any future growth enabled by mergers or acquisitions. This would mean that any unforeseen network protocols would have to be easily incorporated into the general computing paradigm with minimal cost.
End users were first offered access through 3270 terminals and their associated 3174 control units. This method of mainframe access was quickly rejected and is best summed up by Chuck Fleisher, Applications and Systems Development director, "We felt strongly that our mission would not be optimally supported by maintaining a computing status quo. Our computing future required intelligent desktop devices that provide flexible options in both front-end application development and networking protocols."
To that end, Deaconess chose PCs with Microsoft Windows NT Workstation and Windows For Workgroups connecting to Windows NT Servers throughout the enterprise. Because of the need to connect to both mainframe 3270-based applications and Virtual Terminal (VT) applications, Deaconess chose RUMBA OFFICE from Wall Data (Redmond, WA) as their desktop terminal emulator. RUMBA allows multiple, simultaneous session access to the mainframe, and RS/6000 and DEC VAX applications.
Microsoft SNA Server provides the LAN-to-SNA connectivity for access of mainframe applications. Several competitive solutions were considered besides traditional 3270 terminal access.
Microsoft SNA Server was the clear winner for a variety of compelling reasons. "No other SNA gateway gave us the security, reliability, flexibility and expansion potential of Microsoft SNA Server," comments Robert Hodge, director of Networks and Telecommunications. "One solution we evaluated consistently locked up and had to be recycled up to twice a day," continues Hodge. "SNA Server has been running without a problem for over six months. If we have configuration questions, the Microsoft Technical Support staff is very helpful and knowledgeable." Deaconess has opted for support directly from Microsoft via the Microsoft Premier support option.
Figure 1 illustrates the connectivity concept being used by Deaconess. A single desktop platform has access to applications on the IBM mainframe, Windows NT Servers, RS/6000 and DEC VAX. The Extended High-Level Language API (EHLLAPI) capabilities of the RUMBA emulator provide the ability to copy and paste data from remote, on-screen applications to desktop and Windows NT Server applications. In an environment where patient case histories can be extensive, the ability to easily copy specific information between applications increases productivity by reducing the duplicity of keyboard input.
What Is Microsoft SNA Server?
SNA Server is an SNA gateway based on a client/server architecture that provides SNA services for LAN-based PCs running a variety of network protocols. The server can be configured as a PU2.0, PU2.1, APPN Low-Entry Networking (LEN) node or supporting Down Stream Physical Units (DSPUs). LU services provided are LU0, 1, 2, 3 and 6.2. SNA API support is comprehensive with the inclusion of APPC, CPI-C, LUA, EHLLAPI and Common Service Verbs (CSVs) for interaction with host-based NetView. SNA Server allows for comprehensive, bidirectional SNA access while maintaining LAN protocol transport independence.
All popular PC operating systems are supported including Windows NT Workstation, Windows For Workgroups, MS-DOS, OS/2, UNIX and Macintosh. Multiple network protocols including Novell IPX/SPX, TCP/IP, Banyan VINES IP, Named Pipes, AppleTalk and Remote Access Services (RAS) are also supported. By being tightly integrated with the Windows NT Server architecture, SNA Server provides many industry-unique benefits for enterprise-wide, LAN-to-mainframe connectivity. Three of these major benefits, security, administration/ configuration and load balancing, were key selection criteria for Deaconess.
An Extra Level Of Security
As mentioned, SNA Server is tightly integrated with Windows NT Server. Windows NT Server is compliant with U.S. government-defined C-2 level security. SNA Server can be configured to take advantage of this Windows NT Server security feature. Every workstation that needs access to SNA Server must pass security on the Windows NT Server before it has access to any of the SNA services provided by SNA Server. After a user has been authorized for access to server applications, they will then be subjected to standard IBM host security. This extra level of authorization minimizes the possibility of unauthorized access to host resources.
SNA Server Administration And Configuration
Once the host LU names and types (LU0, 1, 2, 3 and 6.2) are designated by the host administrator, SNA Server can be easily configured and maintained via the advanced GUI capabilities of SNA Server and Windows NT Server. SNA Server's tools are designed to allow easy installation, configuration, and management of host and user connections. The GUI interfaces for setup, administration and tracing are a series of dialog boxes and configuration windows that allow an administrator to quickly set up physical connection types, LU pools and even trace activities within SNA Server.
The LU pool configuration provides drag-and-drop configuration ease for assigning LUs for users and groups. Further, SNA Server has seamless access to Windows NT tools such as the Performance Monitor, Event Viewer, User Manager and Control Panel. All these functions may be viewed and managed from one location, allowing administrators to set up and control up to 50 SNA Servers in a single domain.
SNA Server is capable of supporting a variety of physical server-to-mainframe connections. Direct channel attachment, Synchronous Data Link Control (SDLC), X.25, DFT or 802.2/Logical Link Control (LLC) are possible methods of connecting SNA Server to a mainframe. As Figure 1 illustrates, Deaconess has chosen to use Ethernet or the 802.2/LLC option as the physical transport. A series of dialog boxes within SNA Server administration tool allowed easy setup of their Ethernet connection to the mainframe. As a testament to the true ease-of-use of SNA Server, the setup and configuration of one primary and five backup SNA Servers took Deaconess administrators only one day.
High Availability
Due to the continuous examination of quality as required by their overall mission, Deaconess I/S has established a requirement for high availability of host computing resources. Since they are using a service provider at the other end of a T1 link, Deaconess has to ensure on their end that users always have an available path onto the Tl. SNA Server meets that requirement by allowing on-demand connection redundancy and load balancing between servers. In the configuration, a primary and backup SNA Server can be specified. If the primary server fails or is otherwise busy, the backup server will automatically be used. This feature is once again made possible by the integration with Windows NT Server.
In a multiple SNA Server environment, each server knows through periodic update broadcasts which services are available on each SNA Server. In the event of a primary SNA Server failure, the client automatically locates an available SNA Server and a new connection can be established. This capability is used by Deaconess through the configuration of six redundant SNA Servers. The chance of all six servers being unavailable at the same time is minuscule.
Enterprise-Wide LAN Platform
Through standardization on Microsoft Windows NT Server 3.5, Windows NT Workstation, Windows For Workgroups and SNA Server, Deaconess provides a stable and flexible enterprise-wide computing platform on which to develop and deploy new applications. The future of end-user applications at Deaconess includes a front-end application that hides the back-end data sources from users.
Microsoft Visual Basic, C++ and SQL Server are being used in combination to facilitate that effort and provide a consistent user interface for accessing multiple data sources. For Deaconess, Microsoft delivered a complete LAN computing solution that includes integrated client and server operating systems, comprehensive applications and development tools, and a high-performance SNA access solution. This combination is just what the doctor ordered for moving their computing infrastructure into the future.
ABOUT THE AUTHOR
Paul Morse is president of Connect TeXnologies, 39270 Paseo Padre Parkway, Suite 127, Fremont, CA 94538, (510) 249-9415 or on the Internet at: PJMorse@Delphi.com.
