You'd likely be losing more when the packets hit your ISP connection than your router. Most ISP connections (even cable and FiOS or something similar) are like 5-8 Mbps, once the single is split out among everyone in your neighborhood.
I don't know if this is true yet. A lot of places at this point have fiber and you can get 50+ on speed. My town is not the most technological yet they have ran fiber through the whole town.
But either way no miner needs that kinda speed. They use very little bandwidth.