Does the range extender LED light up? Does it work when the range extender is connected to your computer?
If not, i think it is not configured correctly. http://www.tplink.com/en/article/?faqid=357

I have the same need to bridge an IP camera. the range extender is configured correctly and from a PC connected inside the network I can access the camera with no problem. I am forwarding the port (81 in this case) to the static IP of the camera but when i try to access the camera from the outside it does not work. Another IP camera that is closer to the root router wifi and has similar configuration works fine when accessed from the internet.
Is there an issue with port forwarding over the range extender? do i need to do something specific on the root rooter?

thank you

yannis