In 1998, the company managed the allocation and provisioning of services for its customer base with an Open VMS based system, which maintains an inventory of all of its available data communications facilities. This system allows a customer service representative to view all facilities allocated to a customer, as well as enter and manage the process of adding, changing, and removing services for each account. As new orders are entered, the system automatically allocates available equipment and trunks, generating and tracking work orders for installation personnel. Switching facilities are automatically reprogrammed to meet the needs of these orders. Ultimately, a regular transmittal file provides details of each customer's services for billing purposes.
Sector7 has a five-step blueprint process for moving applications from VMS / OpenVMS to Solaris. The first step was an assessment. During the assessment, Sector7 personnel performed an in-depth situational analysis of the existing system. The impact of the critical nature of this 24x7 real time application was considered. X.25, TCP/IP, and DECnet communication links were evaluated. The impact of missing and outdated sources was considered.
Subsequent to the situational analysis, Sector7 worked with the client company to develop a migration approach to fit both tactical and strategic business needs. Sector7 can provide solutions ranging from low risk migration of existing systems and data to completely re-engineered applications using Business Logic Extraction (BLE) methodologies. Migration requires making the minimum changes necessary to allow the code to function in the new environment. Issues addressed include text translation, non-portable code, and hardware differences. This approach is extremely low risk, and may include follow-on efforts to improve both original design and system performance. Re-engineering using BLE requires extracting the business logic from the code to take full advantage of features found in the new system, reusing code where possible, and rewriting it where necessary. Better use of system features and more maintainable code usually result from this process. Often, BLE is selected when organizations have set specific product standards.
The solution selected by the client was a migration, with transformation of the application logic from PASCAL to "C". As an obsolete language, few programmers are now available to maintain the original application programs, resulting in significantly increased expense. Sector7 has tools, which automatically transform PASCAL source files to C, greatly reducing the chance for errors in recoding manually while reducing the time and cost investment in the migration. VX/Pascal provides system library calls which permit "C" programs to easily support various features unique to PASCAL, including DEC (now HP) extensions to the language standard.
In order to avoid costly reprogramming of many operating system specific library calls, the client chose Sector7's VX/RT library, which provides support for most VMS / OpenVMS functions, including SYS$(), LIB$(), and other common routines. Key to this decision was support for both Open VMS style logical names and the SYS$QIO() input/output interface, extensively used by Telstra. VX/SMG provided a Linux-based package solution for the user interface, while VX/RMS provided support for the various file formats used by VMS / OpenVMS, including Fortran-style file formatting used by many PASCAL interfaces.
Much of the application logic of the application is involved with communicating directly to telecommunications facilities. VMS / OpenVMS X.25 communications facility, PSI, is widely used by the application. Sector7's Vx/X25 package provided a seamless interface to Solaris' X25Connect product, which has a completely different programming interface.
All of the client's extensive investment in DCL (Digital Command Language) scripts was preserved though use of VX/DCL, Sector7's implementation of the VMS / OpenVMS command language and environment on Linux. VX/DCL's interface to traditional Linux command shells provide a means to develop new functionality in the native Linux environment. VX/BATCH, used in conjunction with VX/DCL, implemented the complex batch scheduling needs required for implementation of the application.
This successful project allowed the client to retain its valuable investment in software engineering while transitioning to an environment better able to meet its growing needs. Migration costs were offset by reduced maintenance and personnel expenses, resulting from modern equipment and programming environment.
