Access TC over the internet in bridge mode

Hello everybody.

I know it has been discussed already but I still don't have my answer.

I have all the latest firmwares. I'm running OSX 10.8.3 on my MBP. Here is the thing :

- Internet Box (set up as bridge) -------- ethernet ------- Airport Express 192.168.1.1 (set up as router) -------------- ethernet --------------- Time Capsule 192.168.1.2 (set up as bridge)

Everything is working fine except I can not access the TC from the internet.

The AE provides the NAT. So in the TC's panel, which is in bridge mode, the "share disks over wan" tick box is grayed.... It works if I turn it to NAT instead of bridge, but then, I get a double NAT warning.

I set up Back To My Mac on both the AE and the TC and on my MacBook.

When I'm outside, I see the TC in the Finder's "Shared" section. I try to login and I get an error.

Note that I am able to access other devices on my local network from the Internet. In order to achieve that, I redirected some port in the AE's configuration panel.

So, I guess that I have to redirect some ports to my TC (192.168.1.2) but I don't which ones !!! Any idea ?

Thank you for your help !