The issue focused around traffic shaping, particularly around restricting speeds. Verizon apparently allows speeds up to 150Mbps, while Comcast allows speeds up to 300Mbps, while Verizon limits speeds up to 300Mbps, though Comcast doesn't explicitly limit speeds above 300Mbps. 
 
 [ ELI5 : Why does Comcast limit speeds above 300Mbps? ] ( https://www.reddit.com/r/explainlikeimfive/comments/24izxi/eli5_why_does_comcast_limit_speeds_above_300mb@@