Little Background: Microsoft RRAS server and VPN client supports PPTP, L2TP/IPSec, SSTP and IKEv2 based VPN connection. PPTP control path is over TCP and data path over GRE. L2TP tunnel traffic is carried over IPSec transport mode and IPSec protocol internally has a control path through IKE and data path over ESP. SSTP control and data path is over TCP. IKEv2 control path is over IKE and data path over ESP.