Here very simple NAT-PNP/UPnP port mapper, can be used to portforward ports automatically.
Also you can check if your router support NAT-PNP or UPnP.
Can be implemented in releases as external app, credits are must.
Now lets explain what is UPnP:
The UPnP PortMapper can be used to easily manage the port mappings/port forwarding of a UPnP enabled internet gateway/router in the local network.