[Serusers] SER + Radius + B2Bua

Hello, Im trying to make a combination of radius and b2bua to make some prepaid/postpaid billing. Till now I have managed to make SER talk to b2bua and b2bua talk to Radius, but Im not clear yet where does ser or radius stores the call detail records (radacct table is always empty). Also my question about prepaid: is there any database schema that provides tables where I store user credit or so (as it says that b2bua have bundled billing system) or should it be done using radius attributes? If so are there any extra attributes that I have to add in dictionary? Question about ser: When a user registers with radius it registers as username@domain (100(a)some-domain.com) but when I try to call, SER send the call to b2bua using only username ([100]) so the user can not be found. is there any way to register the user only by username? Best Regards Hekuran