After noting claims by users (first reported in this DSL Forum thread) that Comcast was blocking file-sharing traffic, the Associated Press decided to test this assertion by doing some tests of their own.
They were looking for a non-copyrighted, non-infringing work of considerable length. Length, as in lots of bytes.
AP selected the King James Bible, with transfers attempted via BitTorrent from Comcast-connected computers in the Philadelphia and San Francisco metro areas.
That project didn't work out so well.
I'm no way suggesting that Comcast is heathen. I am suggesting that such policies- as they seem to be practiced- are troubling in that Comcast would appear to like to favor some packets over others.
And yea, I've called BitTorrent a den of thieves. But here we have thwarted transfers of a book that to so many, contains the ultimate word against thievery.
"In two out of three tries, the transfer was blocked. In the third, the transfer started only after a 10-minute delay," writes the AP's Peter Svensson. "When we tried to upload files that were in demand by a wider number of BitTorrent users, those connections were also blocked."
Noting that these issues didn't surface on King James Bible transfers executed via BitTorrent over Time Warner Cable and Cablevision Systems connections, no problems were detected.
AP took these results, and determined that the King James Bible transfers via Comcast were attributable to "reset" packets sent during the transmission. These "reset" packets, the AP reports, carried the return address of the other computer.
Here's the essence of what they found:
Those packets tell the receiving computer to stop communicating with the sender. However, the traffic analyzer software running on each computer showed that neither computer actually sent the packets. That means they originated somewhere in between, with faked return addresses.
In tests analyzing the traffic received by a computer on Time Warner Cable that was trying to download a file from a large "swarm" of BitTorrent users, more than half of the reset packets received carried the return addresses of Comcast subscribers, even though Comcast's 12.4 million residential customers make up only about 20 percent of U.S. broadband subscribers. It was the only U.S. Internet service provider whose subscribers consistently appeared to send reset packets (which are occasionally generated legitimately).
Comcast subscriber Robb Topolski, who discovered the blocking earlier this year and traced it to reset packets, pointed out that a Canadian company called Sandvine Inc. sells equipment that promises to save bandwidth for Internet service providers by managing and redirecting file-sharing traffic.
AP noted that BitTorrent Inc. President Ashwin Navin told them that this type of interference is "consistent with Sandvine's technology." Sandvine did not get back to AP with any comment.
Citing competitive reasons and network abuse prevention concerns, Comcast spokesman Charlie Douglas declined substantive comment.
Hey, I wonder what hammer-wielding Mona Shaw is thinking right about now?
Hey, I wonder what you readers are thinking right about now?