PPTP Server

People, Exists some restriction in a server VPN PPTP, to receive connections from customers saw modem and of customers who are in another one lan at the same time? Somebody has one options.pptp that it has accepted connection it saw modem and it saw Lan? I am not obtaining to make with that the PPTP SERVER, has accepted modem connections come, is only obtaining through lan, When I try to connect way modem to server PPTP, it it arrives to soon check the user and password and of timeout after. LAN---------------------/Internet/--------------VPNSERVER(PPTP) Accepted connection and functions correctly Modem------------------/Internet/---------------VPNSERVER(PPTP) time out []'s Fabio Sena