I have a Actiontec GT784WN.
When using it to download games on Xbox One, I notice that the download speed at first is great. Within no time, a 4GB update is at 80% and then the download goes from 150MB/s to 1MB/s.... down to a trickle. Then I spend the next few hours yelling at my router and xbox!
Please help! What is going on? I don't have a static IP and my ISP said that all is fine when they tested things on their end.