Hi all ! I knew that there is tool for an Exchange Server 2000 which calls "Load Emulator" . This tool can emulate loading of the server - we can see how will it work in both situation when we have 10 or 1000000 users ! Is there anything like this for ISA Server 2000 ? I think that it will be useful to knew what is the limit of the effective productivity we can reach . Changing configuration and using this tool are universal instruments which provide ability to configure actual optimization of the server . Best Regards Andrey Silkin IT Manager "ENI REPRESENTATION-OFFICE MOSCOW"