how to maximize comcast upload speed
Best answer Jul 10, 2012, 3:52 AM. In your router admin settings make sure QoS is enabled and set your Upstream (or uplink) to manual. Enter in 40,000 Kbps and then be sure to save your settings. I am a Comcast customer with the same internet plan as you and this fixed my problem with upload speeds through the router. I was getting 1.35mbps and now I am seeing 3.75mbps for upload speeds. Hope this works for you too! Oct 8, 2012, 5:53 PM.