Hi,
SER and freeradius should be installed in the same host, for acc or auth?
FreeRadius can run in the same host or not. It does not matter. You can specify where freeradius is (doing auth and/or acc) in /etc/radiusclient.conf. What you definitvely need at the same host running SER is the radiusclient, which is the process that "talks" to freeradius.
Carlos
Regards,
Lucas