Is accessing my home NAS from my tablet’s app using my ISP data? My NAS is not setup for use from the internet just inside my home. I have always stored video there and accessed it from my Windows PCs via windows networking. Lately I have been watching on my tablet using an app from Synology called DS File and VLC media player. My data use from Xfinity has recently shot up and I’m wondering if this tablet viewing is somehow incurring data use?