After sifting through a wealth of diagnostic messages, I have come to the conclusion that the NAS is the source of the problem. The Session-Timeout attribute appears in Access-Accept and Access-Challenge packets only. The NAS is supposed to keep the value of this attribute in mind for as long as the user is connected, but upon termination of the first session, it discards the the attribute. After the first session, there are only Accounting-Start and Accounting-Stop requests sent from the NAS to FreeRADIUS, and there is no way for FreeRADIUS to remind the NAS of the Session-Timeout attribute. I am convinced that the problem is in the AP firmware. Thank you all for the advice. --- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus