Dear all, We has the problem regarding the above subject... mysql> select * from radgroupcheck; +----+-----------+------------------+----+-------+ | id | GroupName | Attribute | op | Value | +----+-----------+------------------+----+-------+ | 1 | POSTPAID | Simultaneous-Use | == | 1 | | 2 | PREPAID | Simultaneous-Use | == | 1 | +----+-----------+------------------+----+-------+ 2 rows in set (0.01 sec) mysql> select * from usergroup; +----------+-----------+----------+ | UserName | GroupName | priority | +----------+-----------+----------+ | thomas | POSPAID | 1 | | christie | POSPAID | 1 | +----------+-----------+----------+ 2 rows in set (0.01 sec) and at sql.conf.. .. # Uncomment simul_count_query to enable simultaneous use checking # simul_counT_query = "SELECT COUNT(*) FROM ${acct_table1} WHERE UserName='%{SQL-User-Name}' AND AcctStopTime = 0" simul_count_query = "SELECT COUNT(*) FROM ${acct_table1} WHERE UserName='%{SQL-User-Name}' AND AcctStopTime = 0" simul_verify_query = "SELECT RadAcctId, AcctSessionId, UserName, NASIPAddress, NASPortId, FramedIPAddress, CallingSta tionId, FramedProtocol FROM ${acct_table1} WHERE UserName='%{SQL-User-Name}' AND AcctStopTime = 0" .. But.. the same user id still able to login at the same time on different terminal / pc I already try to change the op on radcheck from '==' become ':=' or '=' but the same problem still persist What could be wrong ? TIA PD