wndr3700 port 80

I'm being told by the camera server company that to remote into the camera server, I need to access it via port 80 and that should happen via a link like this:
http://<IPaddress>/enc-cgi/mjpg/video.cgi?camera=1&fps=5&resolution=vga&compressio n=50

Is port 80 going to allow this on my Netgear N600 wndr3700?

I am getting an error when trying to forward the port 80 to this address
The error test starts out: "the specific ports are being used by other configurations..."