Everything should stay behind the router. You don't want the EtD on the open internet.
[open-internet] <==> ISP <==> cable-modem <==> router <==> your-network
your network would have:
* your PC
* your EtD
Another option is to create a private network by adding yet another network card to your PC, and having the EtD connected to that NIC or a switch that sits between the two. (I'm used to the switch, but I've heard that the newer NICs can handle it either way...)