My WiFi Router is a FRITZ!Box Device

FRITZ!Box devices are produced by the German company AVM GmbH. These devices are popular, especially in Germany.

Universal Plug-n-Play: Supported

Most recent FRITZ!Box models seem to be supporting UPnP. You can see more information in your manual, for example here.

For the steps to enable UPnP, You can see their manual on UPnP here for one of the models. A summary of this example is:

1. Open the web interface of your router by visiting http://fritz.box while on your home network
2. Click "Home Network" in the FRITZ!Box user interface.
3. Open "Network" in the "Home Network" menu.
4. Go to the "Network Connections" tab.
5. Click the (Edit) button next to the device you want to configure.
6. Enable"Permit independent port sharing for this device".
7. Click "OK" to save the configuration.

Manual Port Forwarding Instructions

If UPnP is not available, you can set the port sharing settings following this manual.

Please note that regardless of the method, you should see the ports that are opened for your WEPN device by visiting the device's page on http://fritz.box