If the VPN is activated on the desired mobile device, this device is identified as part of the network that the user wants to access. After that the user is able to begin exchanging information via this network.
Against the background of a server-client architecture, a smartphone or laptop represents the client, which establishes an encrypted connection to the server. By activating the VPN server, a connection tunnel is established, which represents the direct connection to the network.
However, access to this tunnel is only granted if the client is clearly identified by the network. If the client is successfully authenticated, this tunnel is passable. This way an encrypted communication with the network can be established.