My brother fits these for a living.
He done my dads recently while we extended the house. Dvr placed securely away and out of the way and the wireless router in the sitting room (upc). He used a wifi extended to bump the signal to the dvr box as we can remotely access it and watch live video stream of any of the 6 cameras or look back through the recordings for up to one month on any of the cameras all on the phone remotely.