SAML2: AS Java configured as Service Provider performs no redirect to Identity Provider

Hi community,

I have configured SAML2 on AS Java 7.4 exactly like described here:

http://wiki.scn.sap.com/wiki/display/Security/Single+Sign-On+with+SAML+2.0+and+ABAP+Systems+Supporting+SAP+Logon+Tickets

I performed all steps from the chapters:

1. Creating SAML 2.0 Service Provider on “Hosting4All”
2. Creating SAML 2.0 Identity Provider (No SAP IdP, but F5)
3. Configuring Trust on the SAML 2.0 Identity Provider Side
4. Configuring Trust on the SAML 2.0 Service Provider Side
5. Configuring Identity Federation on SAML 2.0 Service Provider of "Hosting4All"
6. Configuring an Application to Require SAML 2.0 Authentication (in that case, /irj for the Enterprise Portal)

My configuration did not include any ABAP systems, as I wanted to start with AS Java and IdP first.

When accessing /irj now, no redirect is performed to the F5 IdP (Network Debugger in Chrome does not list anything like this).

Is there a common obstacle?

Thanks and regards, Jannis