Problem in system configuration

Hi

I am trying to define a new SAP system in the portal. I have created the system and have done user management, connector, alias settings. Also I have specified the username and password in user mapping for system access. Even after this, when I am doing a connection test, I am getting the following error:

Retrieval of default alias successful

Connection failed. Make sure that Single Sign-On is configured correctly

Please help me with the missing settings or guide me to any document to create my connection to the SAP backend server.

Thanks and best regards

Anand.