Advanced application types allow UAG to provide access to applications which are not classic "web" applications, and were not designed to be published. As you've seen in Chapter 4, UAG has Host Address Translation ( HAT), a clever mechanism that parses web-based content, such as ASP and HTML pages, and translates the links found in them in real time. If this process were performed, the links that show up on the user's browser would all point to URLs that have the internal server name, and the browser would not be able to resolve them. The translation changes the link to point to the UAG server's public hostname, and the added unique signature helps UAG understand the request and send it to the appropriate internal server.
With some applications, this is not possible. For example, if the application uses complicated code to access the internal server, UAG may not be able (fully or partially) to parse the links, and as a result, the client will try to directly access...