To setup VPN connection on your iPhone, iPad or iPod Touch you need to do the next steps:
Go to Settings > General > VPN.
Click Add VPN Configuration.
Choose L2TP VPN and tap Back
Input you VPN account data - server, account and password. Fill the Secret field - secret (small letters)
Server address must be exactly as in your account data (without http://, www or any other symbols)
Tap Done to save the settings. Once you have created VPN connection you can switch it ON and OFF on the main settings screen.