As a student being quite mobile, I have made use of this service a lot in Germany. Being able to access research network and internet connection, alongside with library access is a great thing. Its even better when you’re abroad at a foreign institute. As it took me some work configuring my macbook network.
For Bonn University, I got information oh which protocols to use right here (in german). Your airport network adapter has to be configured in the more options -> 802.1X network settings. See the figure below for details.
The essential thing was to do a proper configuration of the TTLS protocol. Just log in with your username at uni @ the university’s email suffix. Moreover, keep in mind that there may be an external identity (here: anonymous@…), which is different from your actual identity.