Yes it is the router or the modem.
Faced the same problem with my 7020 running bgox
Had to restart the modem every now and then as it started to slow down and eventually stop
As I am testing ccc now and not connected to any other boxes there is no problme what so ever.
But I am not sure if it is the modem or the router Tested with 3 routers (dlink and netgear) and had the same problem.
Am just about to change isp and also a new fresh modem, hope it will be better stuff