Overview of WinFrame Web Computing

Web Computing consists of three components:

• The WinFrame application server.
  
  
• A Web server, such as Microsoft Internet Information Server.
  
  
• The WinFrame Web client modules (WFICAx.EXE, NPICAx.DLL, and WFICA.OCX), which need to be installed on each PC that has a Web browser. Some Web browsers come with the Citrix ICA extensions already installed, some can be ICA-enabled by clicking on a Web page hot link to install the ICA extensions, and some require that a user perform several steps to become ICA-enabled. (These features are covered later in this chapter.)

One important distinction that sets WinFrame Web Computing apart from the traditional Common Gateway Interface (CGI) and newer Java and JavaScript models is that the Web server does not execute any additional software to support WinFrame Web Computing. The Web server contains files (HTML scripts or Web pages that can incorporate ICA hot links in the form of ICA file references) that can be downloaded to the Web browser for processing. The Web browser downloads and executes the Web page HTML script, which might contain references to ICA files.

If an embedded ICA file reference is encountered, the Web browser downloads and passes the ICA file to WFICA.OCX (Microsoft Internet Explorer) or NPICAx.DLL (Netscape Navigator), which in turn passes the ICA file to WFICAx.EXE. The WFICAx.EXE application then initiates a session on the WinFrame server using the information contained in the ICA file and the application definition to launch the desired application. The application can pass video, keyboard, and mouse data between the session on the WinFrame server and the Web browser.

ICA files can be generated on the WinFrame server by using the Write ICA File option from the Application Configuration utility or, in Microsoft Windows 95 or Microsoft Windows NT version 4.0, by using the ICA File Editor utility supplied with your Win-Frame server for use with these platforms. For more information about the ICA File Editor utility, see your WinFrame documentation.