This graphic shows a typical Services Gatekeeper installation consisting of a network tier cluster with two Services Gatekeeper instances at the bottom, an application tier cluster with two Services Gatekeeper instances in the middle, and a Services Gatekeeper administration server at the top. On the right are WebCenter Portal and Oracle Business Intelligence servers which both connect to the Services Gatekeeper network tier. The WebCenter Portal server connects to the Business Intelligence server and to the external network as well to enable partner access.