Background on Authentication

To access the services, the user must be authenticated against the Deutsche Telekom Security Token Server (STS). Regardless of the selected authentication method, the procedure is always the same:

1. The Client fetches an authentication token from the STS.
2. The Client uses the authentication token for subsequent service invocations.

An authentication token is a string that has to be passed as-is to further service calls. Since it has limited validity, an expiration date is returned as well. How to deal with expired tokens is specific to the selected authentication method.