How to setup Site-to-Site VPN using RRAS Windows 2012 behind router

Hi,

Is there a way we can setup Site-to-Site VPN usingRRAS Windows 2012 that is located behindrouter ?

I understand that Azure is expectedRRAS Windows 2012 on the on-premise side that has Public IP Address that directly assigned to one of its NIC. However, in my environment, the RRAS is located behind the router and I can't expose it directly to internet.

How can i open ports in my router and route traffic to the RRAS ?

Thanks in advance

Noureddine