[Serusers] SER performance degrades dramatically when invalid users send REGISTER messages continuously

Hello everybody, I am using SER 0.9.3 and freeRADIUS 1.0.4 with digest authentication. I am having problems when users with invalid credentials (wrong username or password) try to register to SER. The same thing happens when I insert some records to usergroup table as Reject type in Radius DB. SER is becoming unfunctional in this case in our system. It cannot perform registration and cannot make call for even valid subscribers. SIP clients with invalid credentials try to register and send REGISTER messages continuously. A SIP client sends 20 request/min and there are 7-8 clients available at the moment. i.e. it is not a big traffic. But every client is tried to be authenticated using digest during registration and at the beginning of the call. In such a case, SER slows down very much. Retransmissions starts and SER becomes unfunctional. Did anyone experienced this problem? Do you have any idea why does it happens? Thanks in advance.. Regards, Tulay Sazak NGN, Borusan Telekom --------------------------------- Yahoo! DSL Something to write home about. Just $16.99/mo. or less