# Guide to OpenIG
Chapter 10. Tutorial For the Federation Gateway

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## 10.4. Trying It Out

For IDP initiated SSO click this link

For SP initiated SSO either browse to http://demo.forgerock.com:8080/wordpress/ and click the login link, or click this link

To understand what is happening behind the scenes, take a look at `$HOME/.ForgeRock/OpenIG/config.json`. The HandlerServlet is no longer the entry point to OpenIG processing. If you look for the servletObject at the end of the file you see the HandlerServlet has been replaced by the DispatchServlet. The DispatchServlet provides an internal routing mechanism based on the incoming URI. The DispatchServlet looks at the incoming URI and dispatches to the FederationServlet when the SAML URI is found, otherwise it dispatches to the HandlerServlet as in the previous sample. This allows the FederationServlet to process the incoming assertion, set the attributes from the assertion in the HTTPSession, which then allows the normal chain of filter processing, through the HandlerServlet, to pick up the credentials and log the user into the target application.