Looks like the two RRC's are connected, so you must have a wiring problem. The most common problem
that people have when they experience this is by using the wrong type of cable between the RRC and TS-480
control panel. It looks like a standard telephone RJ12 cable, but it isn't. It must have all wires connected,
commonly known as a 6P6C (6 pin, 6 connected) cable.
If you do have the correct cable(s), then you must have a wiring problem elsewhere.
Note that you do not need to place the control RRC in the DMZ, or even forward its ports. Within the same network,
port forwarding has no effect, anyway. If you need help getting things working when you move outside of your network,
my networking checklist will help you out. Just drop me a mail to dj0qn (at) darc.de and I will send it to you.
73,
Mitch DJ0QN / K7DX