Xfinity Speedtest Speed, What should you have?

Hi, I have Xfinity for my TV,Voice and Internet, I've noticed that most Modems/WiFi Routers have slow speedtest speedtest speeds, how do you fix it? so you need an Apple AirPort router, go to the admin tools by going to 10.0.0.1, type the default username and password which is admin and password unless you changed it, go to advanced, dmz and type in the AirPort's IP address, You should be done! Connect to the Airport and you should have download:50 or more(if you have the best package) and 10 or more for upload(best package too).