Method for connecting a first user-terminal to a second user-terminal, related devices and related software modules

The subscriber data server handles an incoming call request from a first user-terminal in order to establish a connection between the first user-terminal that is connected to a first virtual private network and the second user-terminal that is connected to a second virtual private network. The subscriber data server at first searches in its database for connection information of the second user-terminal and then determines the respective network access server that is connected to the second user-terminal based on the determined connection information. Then the second user-terminal is notified about the request for communication by the first user-terminal. The second user-terminal initiates and controls a switch-over of the connection of the second user-terminal from the second virtual private network to the first virtual private network. The respective network access server of the second user-terminal switches the connection of the second user-terminal from the second virtual private network to the first virtual private network. Then at the switch-over of the connection of the second user-terminal from the second virtual private network to the first virtual private network there is also connection information sent by the adjacent respective network access server to the subscriber data server.