By: Diane Stirling
(315) 443-8975

Researchers at the School of Information Studies (iSchool) and Technology University of Delft have released more current data showing that Internet Service Providers’ (ISPs) use of deep packet inspection to throttle or block BitTorrent and similar file-sharing protocols appears to be slightly declining – but there are interesting exceptions.

The deep packet inspection (DPI) project is a big data initiative that uses a very large database collection of log files generated by Internet users around the world, according to iSchool Professor Milton Mueller, Ph.D., principal investigator on the project. The research is funded by the U.S. National Science Foundation.

Mueller said that the project also just released a draft of a technical paper explaining how researchers made use of the MeasurementLab infrastructure and the issues associated with processing and analyzing the Glasnost tests.  Data and papers can be accessed at the project site,

“What’s significant is that the findings show the use of this technology, after being challenged, is declining a bit. While we don’t have enough evidence to confirm it yet, the countries that are expanding their bandwidth are less likely to use it and less likely to be concerned about this particular [segment] of BitTorrent than they are about other things,” Mueller observed. “It shows that ISP’s might be on the cusp of a change.”

In terms of impact on ordinary Internet users, the data show that the market for excessive bandwidth use may be evolving — through pricing policies rather than technology. Mueller explained: “If you have a new application that uses a lot of bandwith or uses it in an unusual way, it means it is less likely that the Internet Service Provider may single you out for discriminatory treatment; they’ll just say if you use more, you’ll have to pay more. Ideally, that’s the way it would work.” 

Mueller said the new data illustrates these trends:

•    In the United States, DPI use did not increase after an April 10, 2010 court ruling that invalidated the FCC’s Comcast decision.

•    Whereas ISPs in the USA, Eastern Europe and Latin America seem to be turning away from throttling or blocking, major ISPs in Canada and Great Britain increased  use in 2011 and early 2012.

•    Bell Canada increased DPI use in late 2010 and 2011, despite a 2009 CRTC decision regulating Internet Traffic Management Practices and despite a notice to its wholesale customers that its wholesale service “may not be subject” to such throttling after November 2011.

•    High levels of BitTorrent throttling by Rogers Cable also remained unchanged by the 2009 CRTC regulations. Bell Canada and Rogers were both among the world’s top 10 throttlers in 2011 and 2012. Canaca, TekSavvy and Primus also show increases in 2011. (Rogers has promised that 50% of its customers would be free of DPI-based throttling by July 2012 and that they will end it entirely by the end of the year. As of the 1st of March 2012, however, there is no sign of any change.)

•    The UK is another one of the few countries where BitTorrent manipulation appears to be on the rise. DPI measurements for the BT Group in particular increased progressively throughout the 3-year period. Virgin Media seems to have altered its policy and increased DPI-based intervention in the 4th quarter of 2010. The academic network JANET (not shown on the chart) aggressively blocks BitTorrent.

•    Taiwan is another country that shows extensive use of DPI-based manipulation of P2P protocols. Taiwan has one or two of the world’s top throttlers every year, including its nationwide academic network Sony Network, alone among Taiwan’s providers, seems to have reduced or eliminated the practice since late 2009.

The new findings are on the project website at

That information contains a list of the world’s top throttlers in 2009, 2010, 2011 and the first two months of 2012. Liberty Broadcasting of the Philippines held first place in 2012 and 2011, followed by Estonia’s Elisa, Japan’s J-Com Argentina’s Telecentro and Rogers Cable in Canada, the site shows.

Also working on “The Network is Aware” project at the iSchool is Xiang Wang, research assistant. Hadi Ashgari, TU Delft Faculty of Technology, Policy and Management, led the processing of the Glasnost data.