Use tools running on Google’s M-Lab to test your Internet connection. The following tools are cuurently on the site and are very useful indeed. You can check out the site here.
* Network Diagnostic Tool
Test your connection speed and receive sophisticated diagnosis of problems limiting speed.
Test whether BitTorrent is being blocked or throttled.
* Network Path and Application Diagnosis
Diagnose common problems that impact last-mile broadband networks.
* DiffProbe (coming soon)
Determine whether an ISP is giving some traffic a lower priority than other traffic.
* NANO (coming soon)
Determine whether an ISP is degrading the performance of a certain subset of users, applications, or destinations.