I'm not sure about IP address because engineer write it to me. But the structure look like in the picture.
For NAT. If they don't use NAT. We can put only CPU on the router1.
But if they use NAT. If we put CP on Router1, 3,4, 5. How about re-authentication problem? If user already login on Router 3,4,5, Do they need to re-authenticataion on Router1?