If they works on a local LAN the RRC-boxes are OK, they don't see any difference between LAN or Internet. Then the problem is a router/internet issue. Always update to the latest firmware in the routers, lot of routers are sent out with bad firmwares. (specially D-link). But if you don't believe in the system, send them back and you get your money back, I haven't heard anybody else given up before.
73 de mike