Windows 2000 RAS

I am having a problem reciving incomming connections on my windows 2000 server. I have configured a basic ras incomming connection through DUN. This server is not a domain controller, and is not part of any domain (stand alone). I have tested the modem in control panel. The query test was OK. I have even tested dial-out with the server. Dialout tested ok. The error I recieve on the client doing the dialing is “777”. Can some assist? Thanks