It's Time To Play The Game: What's Comcast Blocking Now?

from the answer:-everything? dept

Broadband Reports highlights a new research report out of the University of Colorado suggesting that Comcast has changed its traffic shaping system such that it's sending RST packets for any kind of TCP traffic at times, rather than just for BitTorrent traffic. Comcast has responded saying that this is not the planned change it had announced a couple weeks ago. In fact, the company itself seems confused about the report -- but given the company's own unwillingness to admit to what it was doing in the past, it's hard to know how honest the company is being. Of course, it could just be a technical error. Considering that Comcast's earlier efforts included an accidental jamming of Lotus Notes, a technical mistake might make the most sense. Update: And, it turns out Comcast was correct. The University of Colorado folks have retracted their findings.

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  1. identicon
    Anonymous Coward, 7 Apr 2008 @ 9:40pm

    Comcast is not confused

    They have to know what they are doing. The fact is, now they are screwing up normal web browsing because studies show more people browse the Internet in a web browser than download via a BitTorrent using application.

    Next they'll start blocking ABC and NBC because too many people are watching them, and they now go over the same pipes.

    reply to this | link to this | view in thread ]

  2. identicon
    moe, 8 Apr 2008 @ 12:21am

    Re: Comcast is not confused

    While technically correct, your statement is woefully uninformed. Yes, more people browse the web than use BitTorrent, but BT definitely leads when it comes to the amount of bandwidth used. And, in general usage levels everyone on a Comcast pipe could be browsing the 'net at the same time with no performance issues. However, if a few heavy BT users are on a Comcast pipe it could degrade performance for everyone.

    Traffic shaping/forging packets isn't exactly a simple practice. I'm willing to give Comcast the benefit of the doubt at this point that some of the code isn't working right and that's why it's resetting random TCP traffic.

    reply to this | link to this | view in thread ]

  3. identicon
    Anonymous Coward, 8 Apr 2008 @ 12:22am

    If Congress doesn't pass some sort of legislation to protect the customers, in the next few years we will see internet prices skyrocket. Soon its going to be pay per GB, when that day comes, that will be the death of a large portion of the internet.

    And honestly no one except us nerds care right now and we will be the only ones that care even when every ISP has pay-per-GB system. Mainstream won't care until a few downloads off Itunes a month throws them over their limit.

    reply to this | link to this | view in thread ]

  4. identicon
    Kevin, 8 Apr 2008 @ 3:31am


    I find it amazing that Comcast has repeatedly tried to pull such stupid stunts again and again. I find it even more amazing that they still have any customers left.

    I wonder if it's just Comcast doing this, or if Time Warner, Insight, etc are also doing the same thing and just not getting caught? Is Comcast just the victim of poor design in their ISP network that has left them with far more demand than supply, or are they just too cheap to buy more bandwidth to fix the problem? Why is it that they're the ones always getting nailed?

    reply to this | link to this | view in thread ]

  5. identicon
    moe, 8 Apr 2008 @ 3:54am


    "If Congress doesn't pass some sort of legislation to protect the customers,"

    Protect customers from what? And what exactly would that legislation say or do? If one thing is certain in life, it's that Congress/gov't tends to make more of a mess than it cleans up when legislating the marketplace.

    "the next few years we will see internet prices skyrocket."

    Why? Bandwidth has steadily increased and prices so far have stayed relatively stable.

    reply to this | link to this | view in thread ]

  6. identicon
    mikeinva, 8 Apr 2008 @ 4:03am

    The research was wrong....

    Go back and check the posting. The researchers found out they were wrong.

    reply to this | link to this | view in thread ]

  7. identicon
    Eric, 8 Apr 2008 @ 4:30am

    Re: Re: Comcast is not confused

    BT bandwidth is formidable, however more and more tv stations are offering HD content online and it will soon eclipse any file sharing services.

    reply to this | link to this | view in thread ]

  8. identicon
    Anonymous Coward, 8 Apr 2008 @ 5:08am

    My telco does the same thing.

    - I have dial-up and my telco does the same thing.
    - The practice of sabotage to HTTP/FTP started, coincidentally, just when they started offering DSL in some areas. With dial-up I don't bother with BT. Prior to the DSL, dial-up was dial-up, slow but mostly worked.
    - Funny though, voice is degraded noticeably less.
    - Getting a connection to the ISP is very bad. I usually need to attempt to connect at last 6 times before actually successfully logging in.
    - Once I get a connection to the ISP, I can usually do SMTP.
    - When HTTP/FTP is started I can expect 2-5 dropped connections, and the need to re-log-in, with the attendant difficulties.
    - Now, it sometimes take 30 minutes or more to get a stable circuit.
    - Given that: I am in a semi-rural location, the local telco is a monopoly and the state (PA) Atty Gen is worthless, exactly how is the market to fix this?
    - Market, bah humbug.

    reply to this | link to this | view in thread ]

  9. identicon
    Alimas, 8 Apr 2008 @ 5:09am

    Re: The research was wrong....

    Well, that settles that.

    reply to this | link to this | view in thread ]

  10. identicon
    Tired, 8 Apr 2008 @ 5:41am


    Why is it when someone has a business practice that a select group does not like, or thinks is wrong, do those people stand up and cry "Congress pass a law "???
    The internet and how we access it is changing, we all agree. Comcast is currently trying to change with the times, and eventually they will have to wise up or loss customer base to a larger and growing competetor base, thats how capitalism and the free economy works... you have a service or product, if its good you sell it by the boat load, if its bad you dont.. and the message will get around if somebody has a bad product, then people will stop buying and they will have to change or go under.. which is better motivation in the long run, then laws that will have to be enforced, complicated, and that they will have enough money to throw lawyers and lobbist at to ensure that we in the long run get please if you need to do something start a consumer group to get the word out, not whine to Congress to come and hold your hand and get a a bottle...

    reply to this | link to this | view in thread ]

  11. identicon
    Rich Kulawiec, 8 Apr 2008 @ 6:37am

    This has been discussed elsewhere

    For example, on the NANOG and IP mailing lists. While the Colorado research may or may not be valid, the observations made by numerous other people (including, for example, Steve Bellovin, who knows a thing or two about TCP) still point to something going on inside Comcast's network that doesn't match up with their public statements. It's too soon to say what all this means, so I would recommend following the discussion on the Network Neutrality web site ( to see what develops.

    reply to this | link to this | view in thread ]

  12. identicon
    Dave, 8 Apr 2008 @ 6:48am

    Why people scream

    The reason people beg congress is because the market is broken. Capitialism would work to force change on Comcast if they actually had competition. They were given a monopoly so it is up to the goverment to deal with the problem. I agree that finding a way for competition to get in the space would be the best scenerio but that is not happening.

    When I use Bittorrent my downloads proceed just fine but all of my other traffic is blocked. How or why comcast does that to me I have no idea but hey.

    This very well could have been a technical error. This is a company that gets my bill correct under 50% of the time. I was even triple billed one month.

    reply to this | link to this | view in thread ]

  13. identicon
    James, 8 Apr 2008 @ 7:02am

    Market definitely broken...

    ...but not due to lack of competition, per se, more because these technology companies rather than be honest and realize an opportunity would rather just try to alter the level of service to which a customer is accustomed.

    If BT is really such a thorny issue for comcast they could simply, assuming its technically feasible for them, should break their cable modem service into 2 Tiers, a lower bandwidth (and cheaper) version for non-BT users and a HIGH-bandwidth (more expensive) bandwidth version thats all you can surf.

    I do believe customers, even those that didn't want to pay for, would at least be more understanding of such a move because it would be considered upfront and honest as opposed to this clandestine activity and bs thats been going on.

    reply to this | link to this | view in thread ]

  14. identicon
    Jake, 8 Apr 2008 @ 8:59am

    I could kind of live with ISPs doing this as a temporary measure, but this is not a workable long-term alternative to investing in extra capacity, nor should they be anything but totally up-front and honest about the fact that they're doing it. And frankly, peer-to-peer file transfer technology has been around long enough and gaining popularity fast enough that this really shouldn't have come as a huge shock.

    reply to this | link to this | view in thread ]

  15. identicon
    Jerry in Detroit, 8 Apr 2008 @ 9:30am

    Comcast stupid?

    Comcast provides a complimentery copy of McAfee software for their subscribers. When I attempted to load the software onto a friend's machine, Comcast blocked McAfee from downloading the remainder of the software. I had to power down the modem & restart it so the McAfee installer could download 60 mb of software.

    reply to this | link to this | view in thread ]

  16. identicon
    Joe, 8 Apr 2008 @ 9:32am

    Re: Re: Comcast is not confused

    I can't believe anyone would give comcast the benefit of the doubt after how bad their customer service has proved time and again as well as their underperformance in many markets. I have had comcast twice and both times i wished there was a competitor in the market.

    Comcast customer service as always been atrosious and their service has always been sub par. For 3 months i was paying for high speed internet and connecting to the net at a lower speed then a 28kbs dial up modem. (Tallahassee FL)

    Also we recieved very bad image quality through the digital cable, as well as sub par internet connectivity speeds. It was so bad that our digital cable looked worse then over the air broadcast. (Miami, FL)

    Overall from my experience Comcast is the worst in performance as well as the worst with resolving issues. They don't have the bandwidth or support to back up their claims and are a disgrace to an already shady industry.

    reply to this | link to this | view in thread ]

  17. identicon
    Spike, 8 Apr 2008 @ 11:45am

    It's not about "benefit of the doubt," it's that there aren't many choices. When I most recently moved, I had planned to ditch Comcast and use AT&T for everything. First AT&T told me they couldn't give me Uverse, so I had to contract for satellite TV. Then they couldn't tell me what my "free" calling region was, the support and sales people had never heard of Marin, which I needed for business calls from San Francisco. Finally, they figured out where Marin is but it isn't included even though it's about three miles away. Then, I stupidly let them install and my 3Mbit service got downgraded to 384K after a day because they couldn't give me anything faster (I live in San Francisco and am very close to the CO.) Now it's been four months that I have been waiting for a refund check for the install.

    After all that, Comcast was a) a cakewalk, b) cheaper, and c) more dependable. I never liked Comcast, but they are a whole lot better than the only alternative I have.

    reply to this | link to this | view in thread ]

  18. identicon
    Pro, 8 Apr 2008 @ 11:48am


    I have been a customer for this service which is now comcast for about 15 years and it has always been a top notch internet connection.

    In this case, Comcast IS terminating my connection when I use Bittorrent, and they ARE lying directly to my face about not doing it. My I had to power cycle my cable modem a record 4 times in one hour last night. I PAY for that bandwidth and Comcast should not have the right to tell me what I can or can't do with it.

    user Stephen_ has entered room

    stephen(Fri Feb 29 10:49:39 EST 2008)>RCA modem ceases to function upon Bittorrent usage. Power cycle required

    analyst Ehsan has entered room

    Ehsan(Fri Feb 29 10:49:46 EST 2008)>Hello Stephen_, Thank you for contacting Comcast Live Chat Support. My name is Ehsan. Please give me one moment to review your information.

    analyst Denise has entered room

    Ehsan(Fri Feb 29 10:50:33 EST 2008)>Please wait, while the problem is escalated to another analyst

    Denise(Fri Feb 29 10:50:34 EST 2008)>Hello Stephen_, Thank you for contacting Comcast Live Chat Support. My name is Denise. Please give me one moment to review your information.

    Denise(Fri Feb 29 10:50:39 EST 2008)>Hi, how are you today?

    Stephen_(Fri Feb 29 10:51:24 EST 2008)>Hi, I'm well

    Stephen_(Fri Feb 29 10:51:27 EST 2008)>Thanks...

    analyst Ehsan has left room

    Denise(Fri Feb 29 10:50:56 EST 2008)>Good.

    Denise(Fri Feb 29 10:51:23 EST 2008)>One moment while I bring up your account information.

    Stephen_(Fri Feb 29 10:52:08 EST 2008)>ok

    Denise(Fri Feb 29 10:54:42 EST 2008)>Stephen, may I have your Comcast account number with the date and amount of the last payment for verification please?

    Stephen_(Fri Feb 29 10:55:38 EST 2008)>That's a tough one, cause I'm at work... Let me see if my wife is online

    Stephen_(Fri Feb 29 10:56:48 EST 2008)>She's not. I don't have access to either

    Denise(Fri Feb 29 10:57:08 EST 2008)>Stephen, would you be able to chat back when you are at home, as we will need to go through a powercycle with you.

    Stephen_(Fri Feb 29 10:57:59 EST 2008)>Let's assume I'm who I say I am, what can we do about the RCA modem? The issue appears to be reasonably well documented on the internet

    Stephen_(Fri Feb 29 10:58:11 EST 2008)>Oh, are you going to upgrade the firmware?

    Denise(Fri Feb 29 10:58:29 EST 2008)>I am sorry Stephen, I cannot help you or troubleshoot unless you are at home where the equipment is. I am sorry.

    Stephen_(Fri Feb 29 10:59:32 EST 2008)>Ok. I'll chat back when i'm home today

    Denise(Fri Feb 29 10:59:59 EST 2008)>Thank you for contacting Comcast. If you need assistance in the future, please do not hesitate to contact us through Live Chat or E-mail (available 24 hours a day, 7 days a week). Simply visit and select Help.

    Stephen_(Fri Feb 29 11:00:54 EST 2008)>Is there any know solution for this other than getting a different modem? Is this related to bittorrent traffic shaping?

    Denise(Fri Feb 29 11:03:02 EST 2008)>One moment please.

    Stephen_(Fri Feb 29 11:04:04 EST 2008)>ok.

    Denise(Fri Feb 29 11:09:44 EST 2008)>I do apologize for the wait. Her is some information I found for you.

    Denise(Fri Feb 29 11:09:48 EST 2008)>Do you block access to peer-to-peer applications like BitTorrent?
    No. We do not block access to any Web site or applications, including BitTorrent. Our customers use the Internet for downloading and uploading files, watching movies and videos, streaming music, sharing digital photos, accessing numerous peer-to-peer sites, VOIP applications like Vonage, and thousands of other applications online.

    Denise(Fri Feb 29 11:10:06 EST 2008)>Do you discriminate against particular types of online content?
    No. There is no discrimination based on the type of content. Our customers enjoy unfettered access to all the content, services, and applications that the Internet has to offer. We respect our customers' privacy and we don't monitor specific customer activities on the Internet or track individual online behavior such as which Web sites they visit. Therefore, we do not know whether any individual user is visiting BitTorrent or any other site.

    Stephen_(Fri Feb 29 11:11:40 EST 2008)>ok, I should tell you a couple of things. 1) I'm a software engineer. 2) I'm active in several internet threads currently on slashdot and techdirt that are interested in the result of this conversation. That being said, how can you explain that the only kind of traffic that shuts down my modem is bittorrent traffic?

    Denise(Fri Feb 29 11:13:29 EST 2008)> Please go to,help, and search bittorrent, this is where you can get the information.

    Stephen_(Fri Feb 29 11:14:25 EST 2008)>none of the information there prevents my modem from shutting down when I use bittorrent

    Denise(Fri Feb 29 11:17:46 EST 2008)>Please chat back when you are home, so we can troubleshoot with you as I have already mentioned.

    Stephen_(Fri Feb 29 11:19:25 EST 2008)>very well... however, you should understand that when I get there, diagnostics will be difficult, as when we turn on bittorrent and the connection promptly closes, I'll lose my internet connection and thus my session with comcast

    Stephen_(Fri Feb 29 11:20:04 EST 2008)>but I can discuss that with the analyst that I speak with tonight I suppose

    Denise(Fri Feb 29 11:22:44 EST 2008)>Comcast does not block access to any applications such as P2P, including BitTorrent. We do not alter Internet speed or traffic.

    We respect our customers’ privacy and we don’t monitor specific customer activities on the Internet or track individual online behavior, such as which websites they visit. Therefore, we do not know whether any individual user is visiting BitTorrent or any other site.

    Denise(Fri Feb 29 11:23:10 EST 2008)>No. We do not block access to any P2P applications, including BitTorrent. We also respect our customers’ privacy and don’t monitor specific customer activities on the Internet or track individual online behavior, such as which websites they visit. Therefore, we do not know whether any individual user is visiting BitTorrent or any other site.

    Stephen_(Fri Feb 29 11:25:36 EST 2008)>If that's your stance, that's what I'll post.. But when I told you I was a software engineer, what I meant to convey was - I've worked on protocols and protocol analyzers, I understand how the internet works. you'd have a hard time explaining my cable modem shut downs.

    Denise(Fri Feb 29 11:24:56 EST 2008)>Comcast is not traffic shaping or packet shaping. We have a responsibility to manage our network to ensure that our customers have the best broadband experience possible. That means we use the latest technologies to manage our network to provide a quality experience for all Comcast subscribers. This is standard practice for network operators around the world.

    Denise(Fri Feb 29 11:25:55 EST 2008)>Only thing is to chat back later when you are at home, ok Stephen?

    Stephen_(Fri Feb 29 11:26:50 EST 2008)>Very well... i'll resume tonight when I'm at home. Thanks for your time Denise

    reply to this | link to this | view in thread ]

  19. identicon
    Adrian in Dallas, 9 Apr 2008 @ 5:00am

    COMCAST / Time Warner

    Anybody who has suffered through acquiring "service" through either Comcast or Time Warner, as we have here in Texas over the past quarter of a century, already know that both of these companies are criminal. They behave criminally, they react as criminals, they will always be criminals. They masquerade as legit businesses, much like Blackwater for awful example, but in reality they are businesses that make the Mafia look angelic.

    reply to this | link to this | view in thread ]

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