W2K RAS Connexion Trouble

Hi,
A W2K server is running RAS at my office accepting PPTP VPN connexions.
I've configure my router to translate TCP trafic on the port 1723 to this
server
On the server, I've configured an account to accept RAS connexion.

When I try to establish a VNP connexion, the VPN connexion start (I can see
the connexion with a IP adress with ipconfig /all), some fiew times it
connect, but most of time, the connexion stop with an error (628 or 732).

Can someone help me ?


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P.BOLOT