Port forwarding ppoe

good morning. i have one Wan ISP without nat and the Peplink HD2 is connected with ppoe directly to the internet.
i wan open some ports for the remote desktop but without success.
i applied a routing as follow

protocol: TCP<-- protocol session
port : port mappingg 4000 to 3389

inbound ip seleceted the wan and the ip public

server ip address : setted the internal PC address

don’t work!