When you sign up for their service, your ISP promises you certain download and upload speeds. Now you can keep your ISP honest by testing the download and upload speeds of your service at www.speedtest.net.
This website provides a tool that allows you to ping a server and obtain accurate measurements of your download and upload speeds.
This tool can also help you troubleshoot any problems you might have with internet surfing and video streaming by identifying or eliminating your ISP as the culprit.