Peer Kohlstetter wrote:

I need a tool that give me a report about the consumed bandwidth of a user.

Put the accounting data into SQL. Query SQL.

Is there a tool that create such a report out of the freeradius logs?

It's a database problem. Use a database.

Is it also possible to create a alarm or start a action (Chaning a port Configuration), if a defined bandwidth is reached?

Yes. Query the database, and then run a script if the bandwidth is too high. Alan DeKok.