In the illustration, partner applications A and B are located at two separate middle tiers, one above the other. Arrows show the browser, located just to the left of these servers, authenticating to partner application B and being redirected to the single sign-on server. The single sign-on server sits beneath the two application middle tiers. A dotted-line box attached to the server represents the
policy.properties file. Another arrow shows the partner application serving content to the browser.