How the AP busted Comcast for blocking BitTorrent

In the wake of yesterday's revelation that AP had discovered secret, anti-BitTorrent software running on Comcast's network, a followup story explaining the clever detective work the AP did in rooting out this little shenanigan:
An AP reporter attempted to download, using file-sharing program BitTorrent, a copy of the King James Bible from two computers in the Philadelphia and San Francisco areas, both of which were connected to the Internet through Comcast cable modems.

We picked the Bible for the test because it's not protected by copyright and the file is a convenient size.

In two out of three tries, the transfer was blocked. In the third, the transfer started only after a 10-minute delay. When we tried to upload files that were in demand by a wider number of BitTorrent users, those connections were also blocked.

Not all Comcast-connected computers appear to be affected, however. In a test with a third Comcast-connected computer in the Boston area, we were unable to test with the Bible, apparently due to an unrelated error. When we attempted to upload a more widely disseminated file, there was no evidence of blocking.

Link (via Isen)

Update: And check out thehilarious stupid lies that Comcast Interactive's president told Information Week!


  1. Rogers, a cable provider here in Canada, has been blocking/throttling bittorrent here for some time now.

    For a while it was possible to circumvent the throttling by using encryption, but then Rogers started throttling a variety of encrypted connections under some circumstances (!). https, ssh, etc. started become slow to the point of being completely crippled, while regular http traffic continued to work just fine.

    I’ve recently switched from them to an independent DSL provider. Apart from dozens of confirmations from friends and some mentions on broadband and bittorrent forums online, there has been hardly any coverage of this.

    Some links:

  2. Isn’t the BitTorrent “revelation” old, though? It’s been known that they’ve been interfering with BitTorrent transfers for at least a month or two, I’m pretty sure. I thought the P2P interference was the revelation. Correct me if I’m wrong.

  3. I’m commenting anonymously because I used to work at Comcast. Their biggest fear is commoditzation of their internet product, which costs about 10% of the paying price to provide, the enormous profits offering a story to tell Wall St. in the face of dwindling TV subscribers as they run to DirecTV and FiOS. Let’s face it- their pipes are, by ’09, going to be pure 1’s and 0’s ….and how is that really worth any money? If you’re using torrents to watch the new season of Curb, Dexter, et al, you’re not paying the price for a month of dreary old HBO or Showtime. They know that all the McAfee antivirus and portal videos in the world will never be perceived as value add, (because the AOL model is dead) and they are terrified that we will all wise up, a la Earthlink municipal WiFi, and decide that the pricing on broadband should be subjected to the same liberation as long distance a few years back, and we pay what it’s worth: a 1-200% markup, not a 7-900% markup.

    My question would be: does Peer Guardian Work? is utorrent better? does Protowall help? What’s the how-to? Mark? Xeni?

  4. In response to the comments made by Comcast’s president, I’d like to point to the bandwidth policies of many universities. It’s fairly well known that there is a lot of p2p traffic on college campuses, for a variety of reasons (collaboration on rather large group projects, for instance). The way the university manages this is by providing clear bandwidth caps for both incoming and outgoing traffic. Additionally, the provide a tool/service that monitors your bandwidth usage, and will automatically shut down your connection after it hits a user determined level. The usage of this program/service is completely optional. However, if you go over your allotment, there are a series of increasing penalties, depending on the number of violations in a given time period.

    This set up seems to be a fairly reasonable approach to their supposed bandwidth concerns and one that could be incorporated clearly into their service plans. Their marketing department could even create tiered levels of bandwidth allotments to go along with the different speeds offered to help better educate consumers as to what they’re actually getting. Although, in my limited experience, internet providers don’t actually want educated consumers….

  5. Yes…this was known for months…
    There are lists up and Comcast was on it.

    Here in British Columbia my choices are Rogers Cable, Shaw Cable, and Telus DSL.
    Rogers and Shaw both use packet-shaping.

    Telus does not…and they’re are pretty lax about your monthly bandwidth limits. I switched to Telus after Shaw complained about my “subscriber abuse”.
    The CRTC here in Canada also forces these 3 companies to lease lines to independent ISPs.
    I’m not sure if they use packet-shaping devices or not.

  6. Does this mean I should give my money to that fabulous company Verizon for FIOS? Even though I hate their stinking guts?

  7. My broadband company is owned by Comcast, but it hasn’t been changed over yet. Bit Torrent and anything else useful is blocked on my college’s internet. If Comcast starts blocking Bit Torrent, then I have no place to download stuff that I’ll be wanting on campus.

  8. I don’t get why this is a story.


    Doesn’t seem very scientific. It’s a simple observation.

    Also, I have been on comcast for YEARS and never had a problem downloading torrents. So by my simple, non scientific observation , I could make the opposite absolute claim – “Comcast does not block torrent traffic!”.

  9. This sort of thing has been going on in the UK for a year or two now. ISP’s using traffic shaping or throttling none port 80 traffic to stop people using P2P applications. Largely down to ISP’s claiming to sell “unlimited” connections/bandwidth/downloads then doing everything they technically can to try and stop you using the internet for anything other than standard html web page viewing. They hide small print in contracts saying they can kick you off the network for using such things as P2P applications, streaming video, usenet, emails with large attachments (I kid you not) etc etc. All considered “network abuse”.

  10. @mikelotus: What makes Verizon evil? I have had them for years, and never had a single issue with them.

  11. @sam

    The article also stated that ComCast did not block ALL torrent traffic. But the ones that it DID block (on uncopyrighted files) the computers recieved reset packages NOT sent by the other user, but rather generated elsewhere.

    Was it unscientific…yes. Is it absolute…no. It may just be a trial to see if the software they’re using works…

  12. I don’t quite see how what the Comcast guy said was “hilarious, stupid lies”. He said, “While 99.9% of Comcast customers get access to the Internet without interference, the 0.1% that fit into the category of excessive use have to be managed.

    The blogger then went on to assume that Comcast achieves this ratio by blocking .1% of all customers at random, which is a pretty silly conclusion.

    Obviously Comcast considers bittorrent to be part of that 0.1% and all bittorrent users are squelched accordingly. The ones that aren’t are probably the ones lucky enough to live in an area where the required software or hardware has not yet been implemented.

    At any rate, it seems like a stupid way for Comcast to implement throttling. It would be better to set a bandwidth ceiling and phone up people who break it and tell them they need to dial it down, pay more money or find another provider.

    Those of us who use bittorrent once in a blue moon shouldn’t be penalized just because some people somewhere else are abusing it.

  13. Offering different tiers, packages, or pricing will not work.

    Here in Canada, Rogers (cable provider) has already done that. Thing is it’s all an illusion. Although they offer four different packages/tiers at different pricing, you still dont get your money’s worth with either.

    Even if you’re willing to get the top tier for higher speeds and downloading, for a package clearly directed at high-bandwidth users, you will still be throttled all the same as the guy getting the 4th tier, despite that you dish out $40 more per month.

    On top of that, the advertised speeds are not guaranteed. I was paying for the 2nd tier (2nd best) but often getting the speeds advertised for the 3rd tier. When I called and complained, they told me it was not guaranteed, but an “optimal” or “ideal” speed. Since they could obviously guarantee the 3rd tier speed, I asked that, if I changed plans, would I get that speed. His answer? No, it’d decrease.

    They basically have a license to print money.

  14. @ #3 Anonymous

    the solution is to install an I2P server on your DMZ and route all of your traffic (especially torrents) through it.

    also, check out YaCy the distributed search engine which already indexes I2P “eepsites” (sites only inside the I2P “VPN”).

    which also works well with Dijjer, which is like bittorrent crossed with the Coral Cache

    all three of these are loosely designed to work together to facilitate a distributed and strongly encrypted Internet. this is a technological grassroots solution to create Net Neutrality without government intervention.

  15. According to my calculations Comcast is not blocking BitTorrent traffic. I downloaded something last night and it worked fine. So obviously they are not blocking anything because my single file and connection experience is representative of the whole Comcast network.

    Case closed.

  16. Same here, I downloaded both the CentOS DVD and CD sets this weekend, at 800+ KB/sec using Comcast here in Pittsburgh. Seemed okay, but I had to upgrade my client before it would start downloading properly.

    I really hope that Comcast doesn’t throttle us, because DSL (Verizon) is a poor excuse for an alternative, and FIOS (Verizon) is just as bad — if even it were available in my area.

    I might actually be one of the few Internet users in the area, however.

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