This selection offers a comprehensive look at using MetaFrame to access resources via the web.
In This Chapter:
Citrix MetaFrame provides the ability to access one or more MetaFrame published applications through a Web browser interface.
Application Launching and Embedding
Citrix provides two ways of accessing a Web-enabled application—either by launching the application in a separate window or by embedding it within the confines of the Web page. Collectively, this is known as Application Launching and Embedding (ALE).
Citrix NFuse: Program Neighborhood for the Web
NFuse is the collective name for a number of components that work together to deliver Program Neighborhood application set support to users through a Web browser interface.
Citrix ICA Web Client Configuration
Two different categories of ICA Web clients exist: the Web browser "helper" applications and the ALE clients. Helper applications handle launching an application, and ALE clients provide application embedding support.
MetaFrame Server Configuration for Web Computing
The changes required to your MetaFrame server configuration depend on where your users are located and whether you will implement NFuse.
Web Server Configuration
You need to configure the appropriate MIME type information for the ICA protocol, as well as set up the ICA Java client and install and configure the NFuse Java objects, depending on your implementation plans.
MetaFrame and Firewall Considerations
A question that's becoming more and more common is how to configure a MetaFrame server and client to function properly through a firewall using network address translation. This section discusses the requirements and provides a sample configuration using CheckPoint FireWall-1.
Web-enabling an application is simply the process of providing access to it through a Web browser. Normally, a Web-enabled application is developed explicitly for the purpose of running from within a Web browser. Citrix MetaFrame provides an alternative by bringing a robust set of tools to Terminal Server, which allow for the accessing of one or more MetaFrame published applications through a Web browser interface without any coding changes required to the application.
A Web-enabled MetaFrame environment is made up of four components:
The MetaFrame server. One or more MetaFrame servers in the environment publish the applications that are accessed through the browser.
The Web server. The Web server hosts the pages containing the links that launch the published applications. These links actually point to ICA files also stored on the Web server. The files are downloaded to the browser and then used by the ICA client to connect to the application.
The Web browser. The Web browser is responsible for displaying the appropriate pages published by the server. The browser itself relies on the appropriate ICA helper application to process the ICA file associated with the application link.
The ICA client. Citrix provides a special set of ICA Web clients. These ALE (Application Launching and Embedding) clients can be used to connect to a Web-enabled MetaFrame environment via a Web browser. Four types of ALE clients exist: an ActiveX control for 32-bit Internet Explorer, a Netscape plug-in (16- and 32-bit), and a Java applet. Most of the existing ICA clients also ship with a "helper" application that can be used to access Web-enabled applications. Regardless of the client, the basic function remains the same: processing the contents of the ICA file and establishing the connection to the appropriate published application.
Figure 15.1 illustrates how the components work to establish a published application connection through a Web browser from any supported ICA client operating system.
The user requests the Web page from the server.
The page is displayed within the user's Web browser.
After an application link is clicked, the associated ICA file is downloaded to the client and processed by the ICA client.
Based on the information in the ICA file, the ICA client connects to the appropriate published application within the MetaFrame environment.
A regular MetaFrame published-application session is opened between the client and the server.
Later sections of this chapter look at each of these components in more detail and discuss the configuration changes required in order to implement a successful Web-based application environment.