Whole Home Dvr Service and internet usage

Hello Guys and Dolls first off those who celebrate the thanksgiviving holliday Happy Thanksgiving ,now my question  if you have the whdvr service connected through your router with the deco switches  and you have capabillities to use the on demand service setup this way also , is there suppose to be a continuing usage or draining of  your internet service or bandwith usage or does it just use your internet while downloading a movie on on demand ???