Client/Server Apps

Thin Client computing has become the vision of the future for application software to user’s desktops. “Thin Client” refers to a small, self-contained program that resides on the user’s (client) computer that displays screens and processes only keyboard and screen input. It is directly linked to the “real” program that is running at a remote location....on a powerful server. The two programs operate by exchanging information. The client tells the server what mouse and keyboard actions the user has performed. The server tells the client what to display to the user. This type of software design has many advantages over the early method of software distribution and usage:

• The software and data are installed just once on a centralized server. There are no large installation tasks on the client system…just a simple single file executable program.
• The database is held on a high speed, secure file server with a quality backup plan in place.
• When updates are released there is no distribution; only the server files need to be changed.
• The program is available from many locations available to the user. No need to manage multiple installations and mirrored databases.
• Access to the software can be easily controlled, both at startup and at the lowest procedure access level.
• In any company, configuration and management strategies for departmental usage are trivialized and client hardware requirements are vastly simplified.

There are many, many more advantages that come to light when a specific business model or need is analyzed. Uses from application hosting/rental, WAN program distribution, and support for field personnel are all within the realm of what Universal Systems Solutions offers.

1) One is the actual Program application which “is” the program that contains the full functionality. These are the EXE and DLL files that can run as a standalone desktop application -or- can reside and run on a server running either Microsoft Internet Information Server or an Application Server. This executable communicates with the database, gathers data for all displayed windows, takes care of updates, and formats the reports.

2) The second program is the “Client” application which is also a Windows executable program. This program contains the logic remote User Interface system. As a Windows program it has full access to normal Windows controls and resources such as local printers. When the Client application is started it contacts the server via HTTP protocol and requests that the server run a particular application. The server then starts a new “instance” of the program and provides the client with an identifier so that it can be uniquely identified for future communication with the same instance of the server application. The server application will send the client encrypted, compressed data that tells it the full structure of all windows to display and what data to display in the controls. The client is simply an intelligent assistant that receives instructions from the server to render and manage a user interface. The user operates the program as presented by the client EXACTLY as they would be running the program locally. The Client and Server subsystems handle all user interactions and window updates throughout the session and for all aspects of the application running on the server. Once the application instance on the server is started and it opens a window, the Client then opens an identical window and controls. (NOTE:..The server does not display the window locally on the server for others to view but only to the client.) To the end user it appears that a normal Windows program executes...the only difference being a small green/yellow/red “LED” control on the title bar which indicates when the client is communicating with the server. Typically when a new window is displayed the client and server exchange between 1,000 to 9,000 bytes of data. Thereafter only instructions to update data are exchanged, usually less than one kilobyte per exchange (and most of the time less than 200 bytes!). The Client does not use constant communication streams like other remote client products, helping to keep bandwidth requirements down and server activity to a minimum. This small communications overhead results in a snappy and fast interface for the end user. The client application itself is a one-time download of a single EXE file of as little as 500KB, and may be used for as many sessions or applications as the end user has access to.

If the Client user selects to print a report, the report is formatted and created as a WMF file on the server and sent to the client application. The client application then displays a preview and prints the metafile to the local printer. This means the exact report that is designed for the application is what the client gets....a superior solution to browser-based report layout capabilities. As the client continues to open windows, manipulate controls, or create reports, these actions are executed on the server. Encrypted & compressed communications convey the results to the end user and send new data or commands back to the server. When the end user shuts down the application, both the client program and the instance on the server are terminated. If the end user loses a connection, the server application is terminated when it reaches a timeout value.

Download and Try Our CLIENT/SERVER Demo. You can Add / Change / Delete / Print records you want. This is a Demo Only to the Public.

Instruction!
When downloaded, open the ZIP file and extract the "alconnect55.exe" file to a temp directory. To start the program, simply open Windows Explore and find your "alconnect55.exe file. Double click on the "alconnect55.exe" file and connect to our remote program. The alconnect55.exe will connect after 5 seconds automatically if you do not press the connect button. This will not change or harm anything on your computer.

Client Requirements: An Internet Connection. Also, "WININET.DLL" file must reside on your computer. If you have Internet Explorer loaded, this file should already be loaded. If you are a client behind a network firewall, you must be able to pass TCP throught port 12300 (UN-assigned). We use this port for our demo. Enjoy our demo and let us know what you think.

Click Here to Download Client Online Now (Size: 1,341 kb)

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