It is not unusual that your ISP limit the P2P traffic. As P2P file sharing traffic can constitute up to 75% of all the broadband bandwidth used, IPSs may “optimize” costs by limitting your Torrent traffic.
How do you know if your P2P traffic is limitted?
There is a tool, called Glasnost, that check if your ISP is manipulating your torrent traffic. The test runs BitTorrent and TCP downloads as well as uploads on a well-known BitTorrent port and a non-BitTorrent port. The test takes for about 7 minutes.
I took the test and … good news: it seems that my ISP does not limit my torrent traffic. Maybe it is related to the fact that I rarely use BitTorrent. 
Anyway, you should take the test and check your traffic limitations.
Website: broadband.mpi-sws.org/transparency/bttest-mlab.php via AdesBlog.com
P.S. Are you looking for a solution to anonymize your P2P / Torrent / Bittorrent traffic? Here is a list of premium VPN services.
2 Comments
I took that test today too, it’s complete bullshit, I have comcast and I KNOW for a fact they do throttle me, hell, they start throttling me as soon as I turn on uTorrent now.
This test was not able to detect that/how AT&T throttles torrent traffic.