Remote Desktop Problem

I want to use rdc to connect to offic computer in my home.

In my office router, I have configure to forward to port 3389 (both UDP/TCP) to the server LAN IP.

In my home computer, I have configure my router to forward port 3389 (both UDP/TCP) to my local IP.

I can use rdc to connect to the local server by using local IP in the office.

However, when I use RDC using office WAN IP at home, I can not connect.

Any one can help me? Thanks!