An important part of the way UAG handles applications is the process of URL signing, also known as Host Address Translation (HAT). The URL signing mechanism is what allows the UAG server to publish multiple servers from within the organization, all on a single IP and port.
To understand how HAT works, and why it's needed, let's consider a regular website. The user types in a URL into his browser, which retrieves it from the server. The web page typically contains links. These can be images, which the browser automatically retrieves from the server, or actionable items, such as 'blue' links to other pages or various types of action buttons. These links can point to resources on the same server or another.
When a page is visited through UAG, we have a challenge. The back-end server has a certain name, which is often part of the links. For example, the page http://accounting01/home.htm
may have a link to http://accounting01/tax/calc.htm
. If the accounting...