Trouble connecting iOS devices with VPN network

Hello,
I'm publishing this concept after several problems in establishing my VPN network on my iOS gadgets (both my iPhone and iPad). The VPN network is operating incredibly well on my PC, so I think that the machine or my options (ID and passwords) are appropriate.
I have also tried to get some assistance from some of my friends but they are also unable to fix the problem. I guess, it would be better to publish my websites created in both PPTP and L2TP network method. Anyone could inform me where did I go wrong and how to address the issue.

