Products and the Internet
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
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.
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 Client and the Internet
The DSC THIN CLIENT is a WINDOWS based application
program running on a WINDOWS processor which links a users 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
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 users
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 browsers 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.
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.