Yes, it will run thru the router, but it will run in the Demiliterized Zone, which should be the same as running a switch after the modem. Only difference should be the IP address assigned by the router instead of the modem. Are the IPTV boxes picky in terms of their IP addresses and which box (router or modem) they are connected to? While this might work, you might find that certain services are not available. It depends on whether or not the modem supports specific services by passing their IP address to the IPTV boxes. If you connect the IPTV box to a router, there is a good chance that they won't be able to receive those IP addresses thru the router. Only way to find out is to experiment. Does the ISP advise the IPTV users that router use isn't supported? If so, that would be the reason why, the modem is paired with the IPTV box to provide all of the services that the ISP will provide thru the IPTV box.