European ISPs block/throttle BitTorrent traffic

The results show that three of the nine ISPs interfered with BitTorrent traffic flowing through the standard port 6881.

This wasn’t the case on all tests, so the researchers selected these providers for a more thorough follow-up run.

This “focused” test looked at the average download speeds for the following traffic types, which were (except HTTP) all similar in respect of types of packets and size.


The researchers found that Vodafone always blocked BitTorrent traffic on port 6881, except between 1 AM to 5 AM. However, BitTorrent traffic was blocked on higher ports as well. This led to the suspicion that it takes place through deep packet inspection.

It will be very interesting to run same/similar measurements to Portuguese ISPs and find out how they do traffic classification.