NAS is the central storage of all your data. For myself, my computer will back up all of my documents, source codes and photo to my NAS automatically. So, this is a heavy load in the local network. That is the reason of all NAS with ethernet only, no wifi at all. Everyone want to get a connection to the NAS as fast as possible and as stable as possible. For myself, because other family are using the network too, So, I put my NAS in a separated switch with all of my devices which is required the back up service to there. Firstly, the heavy work load in the network won't affect the other part of my home work. Also, I can get the fastest and most stable connection to the NAS too.