Comcast Throttles BitTorrent Traffic, Seeding Impossible
Written by Ernesto on August 17, 2007Over the past weeks more and more Comcast users started to notice that their BitTorrent transfers were cut off. Most users report a significant decrease in download speeds, and even worse, they are unable to seed their downloads. A nightmare for people who want to keep up a positive ratio at private trackers and for the speed of BitTorrent transfers in general.
ISPs have been throttling BitTorrent traffic for almost two years now. Most ISPs simply limit the available bandwidth for BitTorrent traffic, but Comcast takes it one step further, and prevents their customers from seeding. And Comcast is not alone in this, Canadian ISPs Cogeco and Rogers use similar methods on a smaller scale.
Unfortunately, these more aggressive throttling methods can’t be circumvented by simply enabling encryption in your BitTorrent client. It is reported that Comcast is using an application from Sandvine to throttle BitTorrent traffic. Sandvine breaks every (seed) connection with new peers after a few seconds if it’s not a Comcast user. This makes it virtually impossible to seed a file, especially in small swarms without any Comcast users. Some users report that they can still connect to a few peers, but most of the Comcast customers see a significant drop in their upload speed.
The throttling works like this: A few seconds after you connect to someone in the swarm the Sandvine application sends a peer reset message (RST flag) and the upload immediately stops. Most vulnerable are users in a relatively small swarm where you only have a couple of peers you can upload the file to. Only seeding seems to be prevented, most users are able to upload to others while the download is still going, but once the download is finished, the upload speed drops to 0. Some users also report a significant drop in their download speeds, but this seems to be less widespread. Worse on private trackers, likely that this is because of the smaller swarm size
Although BitTorrent protocol encryption seems to work against most forms of traffic shaping, it doesn’t help in this specific case. Setting up a secure connection through VPN or over SSH seems to be the only solution. More info about how to setup BitTorrent over SSH can be found here.
Last year we had a discussion whether traffic shaping is good or bad, and ISPs made it pretty clear that they do not like P2P applications like BitTorrent. One of the ISPs that joined our discussions said: “The fact is, P2P is (from my point of view) a plague - a cancer, that will consume all the bandwidth that I can provide. It’s an insatiable appetite.”, and another one stated: “P2P applications can cripple a network, they’re like leaches. Just because you pay 49.99 for a 1.5-3.0mbps connection doesn’t mean your entitled to use whatever protocols you wish on your ISP’s network without them provisioning it to make the network experience good for all users involved.”
Customers on the other hand like to fully use their connection, and don’t agree that traffic shaping is the correct solution. One reader commented: “If you pay for an internet connection, that’s what you should get from your ISP — an internet connection. Not a connection that will let you browse the web and check email, but little else. If an ISP has issues with the amount of data a customer is transferring, then the ISP needs to address that issue with that customer, and not restrict every user in one class of traffic.”
I guess this battle will go on for a while and I would advise Comcast users to try setting up a VPN connection to get around the traffic shaping, other users who find out that they are throttles might try BitTorrent encryption first, that seems to work quite well in most cases.
More details about the Sandvine application can be found here.
Previously: BitTorrent Anime Downloaders Identified, $3500 Bill in the Mail
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@Alex S
* First a bit off-topic but…
“[...]site is very open and atheist, and thinks that everything is ok and moral. Sorry guys, I’m not like that, I’m going to stick w/ my morals[...]”
Won’t let this slide, sorry. Atheists, agnostics, etc; all have morals as everyone, with exception to sociopaths, know what is right and wrong– they are part of society so they accept (or not) the rules of society. It is very disrespectful of you to regard people as not having any morals. Besides, if they didn’t have morals, would they hesitate to harm you? I mean, without morals, is it wrong to kill? Do not assume people that do not subscribe to your favorite deity or way of life are immoral or amoral. Please be respectful.
… anyhow back on topic.
The job of ISPs are to provide access to the internet. The content that passes through their lines is of no concern to them. If they inspect the contents of their lines they lose common-carrier status and become liable for content that is on their lines. That being said, morality has absolutely nothing to do with this– they are just trying to find ways to reduce their own internal bandwidth costs to maximize profit. P2P and other video services are /expensive/ to handle as they will use whatever bandwidth is available to them. Because Comcast is unwilling to supply enough bandwidth for the demand, the quality of service for heavy-use nodes degrades with each additional P2P/heavy-use user on that particular node.
Who’s at fault here? Both comcast and the user. P2P does have its legitimate uses, but come on, how many people do you think are /really/ is using it legitimately /all the time/?
I must say though, I have and often use BitTorrent for legitimate uses and the blanket banning of it is obscene. What do I send via BT? Application packages, updates, source packages, etc. I find it better than using a single download host, and Comcast or anyone else cannot convince me otherwise– 80kb/s
… 80kb/s < 3.3mb/s.
Sorry for the double post but this apparently doesn’t filter the greater-than or less-than signs properly. Probably doesn’t filter html either.
This is a load of shit. Bittorrent can be used in situations not involving pirating, and it saves a hell lot of bandwidth from the site too. If more ISPS start doing this, we’ll start a strike. First off, no seeding means no uploads, no uploads mean no or less downloads.
Lemme guess, stop downloading too huh? Yeah, that’ll be “swell”. We like wasting bandwidth, don’t we…….
Do this, find a few dozen sources of legal BitTorrent distribution systems like Vuze, make a nice list. And contact your politicians and the media.
ISP’s can perfectly add a few fiber optic connections to the different backbones. Using the full bandwidth is what everyone should be doing.
The conspiracy is that ISPs don’t want to move from ADSL/Cable to Fiber to the Home, and they don’t want to move from 3G to 4G. They think it’s nice to make huge sums of money on old technology, so through their monopolies, they slow down innovation.
In other countries then the USA, people have unrestricted 100mbit/s connections with near unlimited multi gigabit peering between bandwidth providers. Every new house and building should get a fiber optic cable included by law in the construction, it costs nearly nothing to pull a fiber optic connection to every new home, just as every new home should only be constructed if it respects energy concervation principles in terms of saving energy.
Xiata:
“Who’s at fault here? Both comcast and the user. P2P does have its legitimate uses, but come on, how many people do you think are /really/ is using it legitimately /all the time/?”
Let me point to the recent case of the BBC iPlayer.
“Leading UK internet service providers (ISPs) are warning they may have to restrict customers’ access to the BBC’s new iPlayer service unless the corporation contributes to the cost of streaming videos over the internet.
Internet companies such as Tiscali, BT, and Carphone Warehouse have raised concerns that the iPlayer, which allows viewers to watch TV shows over the internet, will put too much strain on their networks if it becomes popular among a mass audience.
Streaming TV shows takes up a lot of bandwidth and could clog up the network, severely slowing internet access speeds at peak times. …”
http://www.ft.com/cms/s/e6d0e9d0-4934-11dc-b326-0000779fd2ac.html
And there are several more involving YouTube, Joost, and other services being blamed for the saturation of the net besides other p2p ( legal or not ).
The fact is, most ISP’s still have a 10 year old attitude. Lets advertise 1Mbits, no, 3Mbits, no 10Mbits. Big numbers sell well. But, when people start using there connections at a high percentage, then the backbone infrastructure of the ISP’s drops like hell.
And they have only one answer to it. Blame the user, blame the company’s providing the bandwidth “wasting” content. I don’t give a rats ass if company’s like to make profit by overselling there products.
When a ISP claims 3Mbits, and a high percentage starts to use there lines, they have no right! to complain, block, or do other shit. Its there job! to provide the “tubes”, and if they don’t evolve with the growing need of the net, trying to maximize there profits, well … We see the effect.
And don’t give us that “but its expensive to upgrade” line. Most ISP’s around there are offering the same service they offered almost 5 years ago. Thats 5 years worth of time to upgrade. A time where 1GB of bandwidth was expensive as hell, to peanuts now. And they better stop wasting money with those anti p2p system they buy. The effect is, encryption, vpn’s etc are going to become more & more commonplace in order to deal with ISP’s like this.
Its the ISP’s job to upgrade in order to deal with the growing demand of online services. Cheap ass tricks like this only hurt a ISP in the long run. Because it opens up market area’s for new ISP’s to step in.
And what of the people who use bittorrent for legitimate means???
Way to drop the ball, Comcast. I’ll stick with my Usenet.
I disagree that Bit-Torrent is mostly illegal. In fact, most Linux distros are passed around via Bit-Torrent. Much open source software is distributed via this protocol as well. The illegal activity is mostly Microsoft software and audio/video.
*
It’s possible that the Linux folks may have a case against the Comcast creeps.
What about switching ports?
It’s funny how ignorant everyone in this thread is.
thanks the iptables worked on busybox/ssh on the wrt54G router. just remember that there’s double dashes not the unicode before DPORT and TCPFLAGS
This is really sad when you consider that 99% of Internet communication is p2p in the technical sense. Shaping traffic like this limits approved peers to the likes of youtube, sony, google, ebay, amazon, yahoo, sears, etc… This is not good for the common citizen. The Internet is fundamentally a point to point network and that’s why we love it. Any point to point (or person) protocol, including http, can be used to pirate lame music. Time to start using ssh for everything.
I hope they are openly advertising this service to their customers. Because if I was one of them I would be pissed. I mean it’s our bandwidth we can do what we want.
I can’t imagine this is the kind of publicity and good feedback that they want, (and I’m not sure how much of the US they offer their services in), but Cox has been nothing but great since we got broadband five years ago.
Would super seeding help? I believe this makes you appear as another ‘peer’ instead of a ’seed’ although you already have the entire file.
i think that Ponce’s comment is perhaps the best way to battle this legally. Comcast can be broken just as AT&T was in the 80’s. When the rights of another business are involved the governing body tends to move in the direction of the most money, but at some point they can be directed toward public benefit.
[quote comment="148317"]Seems anti-competitive to me… Comcast sells internet access. They also sell video subscriptions, charging extra for on-demand and PPV movies.
If I’m paying to DL a movie from a legal subscription service that uses the bittorrent protocol, and it’s blocked, that’s anticompetitive behavior designed to get me to use Comcast’s services instead of the competitors.
Dorkbags. Grrr.[/quote]
This is hardly news, we already listed it in our wiki 2 months ago:
http://azureuswiki.com/index.php/Bad_ISPs#United_States_of_America
[quote comment="148298"]I fucking hate Comcast. I need a new broadband provider. God fucking damn it, this fucks my day over.[/quote]
Ben, I’m with you bro. I use Linux and always keep a ssh port open so I can remote into my box if I want to look at pr0n at work.
I always end up with a connection reset these days.
As for my BT story.
Comcast, Ft.Lauderdale.
I can upload fine WHILE downloading. Once my download is finished I can’t seed for shit.
So I usually just end up maxing out my upload when I do download so hopefully I get the 1.0 share ratio before it dies.
Guess I better start testing thing.
I think I’m gonna make a comcast-sucks.com website in the near future.
So lets all band together and bitch!
Gotta double check, but since I have state enforcement on my OpenBSD firewall I think I’m dropping these foreign RSTs by default.
Comcast will have to spoof the IP too.
Lazy bitfield doesn’t help and encryption doesn’t help either. For some reason, files with a lot (more than 20) peers seed much better than those that have few peers. It’s not as good as before they started pulling this crap, but it’s enough to keep my ratio from plunging.
I can’t believe the people who are defending this. They want me to pay big bucks for a net connection that promises high speed; they just don’t want me to use it. Can Qwest really be worse than this?
People love to control other people, it’s human nature. If you gave someone a lot of power, there’s a 90% chance they’d use it to benefit themselves and screw everyone else. Comcast is out to make money, just like all the companies that make the software you pirate. They want to stop you from taking their little piece of the pie and don’t care how they do it. So, unless you gain some kind of control yourself, you’re stuck eating what other people want to feed you. That’s the human race, deal with it or get out of the way.
Just encrypt the data transfer within the Bit Torrent client. It causes the CPU to spike a little more, but the ISP cannot track what is going in and out of your comp…
“If an ISP has issues with the amount of data a customer is transferring, then the ISP needs to address that issue with that customer, and not restrict every user in one class of traffic.”
Or, more realistically, if an ISP has a problem with it, the should *Disclose* that restriction in their advertising and to new customers. But they won’t because they know consumers won’t like to hear: “*Comcast internet service is not ycompatible with networked games, Usenet, BitTorrent or other P2P services” That doesn’t sound like a selling point, does it? So instead, the obscure their real policies and the unsuspecting consumer finds out long after they’ve signed up. Sounds to me like a deceptive trade practice (kind of like what Comcast is doing in MD by requiring people to “opt out” of their insanely one-sided dispute resolution/mediation contract clause).
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