We are on Rural Broadband with an 80gb data limits. Since the rollout of the new sky we have noticed (perhaps purely by coincident) that at certain times our data gets chewed up at an alarming rate and we can't make it to the end of the month.

Does Sky randomly download data to the box with no user input? The data is being used whilst no one is at home and the only devices on and connected are the sky box and a Dlink dns320-L NAS Box.

If not I can eliminate this a a possible cause. Is there any software available to monitor which device is using which data on the network?