I modified my SQL function a little bit and restarted all the APs on the site and truncated the radacct table and now each and every row in the table has a true username. (At least for now...) I think the problem was because I reconfigured a live FreeRADIUS setup to use SQL instead of flat files. (After designing and testing in my home lab, of course.) Since the NASes (30 Unifi AP-LRs and 5 Ubiquiti Nanostation M2s) do not properly carry out the session timeout policy declared by FreeRADIUS and are not configured to terminate sessions at regular intervals, theoretically a session could last forever. When I made the transition to SQL, the NASes did not forget about the old session data and kept sending FreeRADIUS back accounting packets using the old settings, ie *without* the Class attribute. Thank you all very much. I am new to FreeRADIUS and it has been quite a steep learning curve this past week. I must say FreeRADIUS is very solid and has a very clean and clear design. I believe FreeRADIUS has a future and I'd like to learn more about it. Could you please recommend a book? Best regards. Selahattin CILEK --- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus