Database Systems Corp. has developed web-enabled products that satisfy a number of customer needs and requirements. Traditionally, DSC products have operated over direct connect RS232 cable, local or wide area network (LAN or WAN), or modem connection. Since the advent and acceptance of the Internet, DSC now provides several methods for our customers to access their software applications using the World Wide Web. This access can occur either via GUI screens or traditional HTML forms.

There are two methods of connecting Internet users to DSC based applications. The first method is via DSC's THIN CLIENT program which is a Windows based application program running on a PC. The DSC THIN CLIENT can communicate to a DSC application program through the Internet and lets Internet users perform all of the functions available to local users. Another approach is through the DSC Web Designer system. This method provides a framework for accessing a database using HTML.

The advantages of this connection are many, but the most obvious is the reduction or elimination of long distance telephone charges for users who need remote access to applications developed using DSC products. The Internet provides a cost-effective alternative to local or long distance phone service. Of course, Internet users must still subscribe to a local Internet Service Provider ( ISP ). Using the DSC's THIN CLIENT, this access through the Internet is performed in a much more efficient manner than using traditional character mode terminal emulation on the Internet. This will be described in more detail in this document. The other major advantage is the access over the Internet provides users an ability to access Corporate data either via Web browsers or the same GUI screens used locally.

To take advantage of this Internet connection requires that DSC based applications (or at least one piece of this application) reside on a system that is connected via LAN to the web.  Through an ISP, your LAN must be registered on the Internet.  To develop DSC Web Designer HTML forms connected to an application, the user must maintain his own Web Server computer. This server is connected to the LAN to enable Internet users access to application programs residing on any computer connected to this LAN.

A Web Server is a computer system maintained on the LAN. This computer system is accessible by web browsers who request and submit web pages from the site. The LAN is registered on the web through an ISP. Typically these computer systems are Unix or Linux based processors running web service software – the most common being Apache which can be provided by Redhat Software, Inc. for Linux based systems.

The is a key component required to link DSC software and web browsers on the Internet. It serves as the communications link between the Internet and Application Computers running DSC applications. 

DSC Client and the Internet

The DSC THIN CLIENT is a WINDOWS based application program running on a WINDOWS processor which links a user’s desktop with any DSC application program (DSC Server).  This client process provides users with a true GUI presentation of a DSC form or display. The connection between the DSC Client and the DSC application program is through TCP/IP. The Client can communicate with any number of TELEMATION or TRANSACT based application programs. 

The DSC THIN CLIENT need not reside on the same LAN as the application program. The connection could just as easily be through the Internet. Thus the DSC THIN CLIENT could reside on a user’s PC, which when connected to the Internet through its ISP, could link to a remote LAN which is itself registered on the Internet. This functionality is not unique. Any PC terminal emulation that links to remote systems, such as PC TERM, NET TERM, Reflections, etc. can perform the same connection. However, the performance of character by character operations over the Internet is relatively slow.  A significant degradation of performance is noted when attempting this terminal emulation over the web.

The DSC THIN CLIENT, on the other hand, performs PC to application data transmission using message blocks, which is much more efficient, particularly over the Internet.  Thus the execution of an application over the Internet communicating with the DSC THIN CLIENT appears to the user as if the connection is over a LAN rather than the web. Of course, the modem connection speed still plays a significant role in overall performance. The application of this technology is far reaching.  Remote users (salesmen, managers, administrators, etc.) can now have access to their data centers by simply accessing their local ISP, and not be concerned about long distance service or billing charges.  This functionality could be very attractive to organizations with a remote sales force requiring real time order processing and status updating. Call centers can now employ users working from home or remote offices.

Of course, this readily available access to the data center will require the systems administrator to be much more concerned about security and password controlled software access. Any time a LAN is registered on the Internet, there is need to implement a firewall protection scheme to prevent the unauthorized access to this  LAN.

DSC Web Designer

The DSC Web Designer system is a product developed by Database Systems Corp. to give users full web page access to database applications. This product lets developers merge database information with existing web pages. Information can be collected from Web Browsers and distributed back to these users.   These web pages can interact with any DSC based database and application program. There are three software components to this system.

DSC Web Server

The DSC Web Server program resides on your Web Server Computer system. Its primary function is to accept web page information from the Web Server software (i.e. Apache) after a user on the Internet submits a page to your site. It processes this information and transmits it over a network (or Internet) to the DSC Web Master program. The Web Server waits for a response from the DSC Web Master program (in the form of a response web page) and transmits this result page back to the original user on the Internet.

DSC Web Master

The DSC Web Master program can reside on the same system as your application program. It must “reference” the dbase (Database Systems Corp. internal dictionary directory) used by your application programs. The Web Master program does all of the database and application work for you. It is invoked by the DSC Web Server program and interprets the information contained on the submitted web page. This web page was submitted by a user who designated a specific ACTION to occur.

The DSC Web Master accepts this action request, along with the data contained on the web page, and acts upon this request. This could be simply adding a record to a database (Registering), or could involve a more complicated operation involving an EZTRAN program or a TRANSWRITER report. After the operation has been processed, the Web Master will produce a results web page. This could be a simple acknowledgement page, an error page, or a more complex display of information. Once this page has been built, it is transmitted back to the waiting DSC Web Server process.

DSC Web Designer

The DSC Web Designer utility performs the design and development of web pages. This program lets you define input forms for data collection from the Web Browser or lets you merge information from your database with existing web pages for presentation to the user.

The DSC Web Designer web page is a unique, self contained page of information which includes data elements or fields, descriptive text, graphics, and most importantly, ACTION buttons which may be depressed by the web user to perform any number of discreet tasks when the page is submitted. The DSC Web Designer program gives the developer a tool to define both the information contained on each page as well as the actions to be performed by each button. This utility is a WINDOWS based program which must be attached to the dbase where the application screens, programs, and database reside.

The Web Designer can automatically build web pages from application screens or windows. Data from existing databases can be accessed, updated, removed, displayed, and reported. EASYTRAN programs can be executed from the web. Background processes can be initiated and data transmissions (email, faxing, etc.) can be performed. With TELEMATION, agents could be prompted to respond to a Web browser’s request.

The result of each action is the production of a web page which is returned to the web user. Thus, when each action is defined on a page, it must inform the DSC Web Master what page to return to the user. For example, if the action button on a page invokes a report, the resultant page could be the actual report itself (or a page from the report), or simply an acknowledgement of the fact that the report was produced and sent to a printer or other output media.

Since the connection with a web user may be broken at any time (either by the browser or because of a dropped line), each page and action must produce a discreet result. Pages are totally self contained, such that if a web user were to hit the Back Arrow and resubmit this page, the operation could be successfully performed with no prior dependency. This does require the web designer to focus on distinct and discreet functions when developing web page applications. Thus some computer applications do not readily adapt to web operation.

Summary

DSC now offers its customers two methods of enabling their software applications on the Internet. Using the DSC THIN CLIENT, production applications can be accessed by remote users in an efficient manner. Web pages can now be designed or modified using the DSC Web Designer utility as an alternative. Application programs can now be designed to run both on a Local Area Network as well as on the Internet. The user interface can be a traditional WINDOWS GUI presentation or a Web Page based front end.