We open Settings menu.
We open now the General submenu.
We choose Network.
Now we click on VPN to configure it.
We Add a new VPN configuration.
We enter now all configurations details for the PPTP VPN :
Description: TUVPN (i.e.)
Account: Your VPN account name (tuvpn_....)
Pasword: Obviously, your VPN password
Send All Traffic must be ON (default)
And we connect to TUVPN.COM and all our mobile communications from our iPhone are protected !