Android PPTP And L2TP VPN Implementation

I am working on an Android VPN app for Android 4.0 ICS and above. The app function is to provide one click connection to a VPN server with using PPTP or L2TP prtocols, the user will have the choice to use any of these prtocols and will supply the username and password. What is required is to provide full and stable PPTP and L2TP implementations using the VPNService API provided in the Android SDK. The project specifications:- 1)Provide PPTP And L2TP implementations using VPNService API and both implementations must successfully connect to the server and provide speed test. 2)Provide one example on how to use each protocol implementation. 3)Stable surfing on the internet. 4)Provide complete and readable source code of both PPTP and L2TP implementations.