>I have a RAS service runing on an NT 4.0 server and I want to avoid that the same user might be authenticated more than two times at the same time.
>For example, if the user "bill" is conected to the modem 1 I want to avoid that this user might be authenticated again (at the same time) in the modem 2 from another machine.
>Can I do this with the resources avaliables on the NT authentication system, or I must use a third party product?
>

I haven't tried this, but I think you could do this using System Policies invoked during the login process.

>I will be grateful if anybody can help
>
>thanks
>
>Pedro