I've put together a diagram showing one of the scenarios where the Vordel Gateway operates with various Oracle Identity Management products. The scenario, which is very common, is Identity Propagation. If a client is authenticated at the Gateway, it's usually important to propagate their identity right through to the app server tier, because otherwise all requests may appear to simply come from the Gateway. It's also important for audit trail reasons (you need identity information available if you want to keep a trail of who has accessed which service).
One of the underlying technologies used for this is SAML, and you can seem more information about how we do it in this blog post I wrote after setting this Vordel-OSB interop up myself. You can follow these instructions to setup the identity propagation scenario.
In the diagram below, the Vordel Gateway is working with a number of Oracle IM products (OAM, OES, OVD, OWSM - see a naming pattern there? ;=) ) to provide end-to-end identity propagation from the edge of the network through to the app server.
For more information about Vordel Gateway interop with many Oracle products, check out http://www.vordel.com/oracle