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Comcast’s Wrong Approach

Internet Service Providers (ISPs) have to do a lot more than just provide a pipe from your residence to their facilities to assure that you have a good Internet experience. There is a raging debate, inextricable from the debate on Network Neutrality, both on what the proper responsibilities of an ISP are AND what methods are proper for carrying out those responsibilities.

Recently Comcast has received a serious black eye for blocking BitTorrent traffic in what it says was just a legitimate exercise in protecting most users from the few who abuse their “unlimited access”.

For this discussion to make sense, you have to know a little about what BitTorrent is. Can’t do better than the Wikipedia description:

BitTorrent is a peer-to-peer file sharing (P2P) communications protocol. BitTorrent is a method of distributing large amounts of data widely without the original distributor incurring the entire costs of hardware, hosting and bandwidth resources. Instead, when data is distributed using the BitTorrent protocol, each recipient supplies pieces of the data to newer recipients, reducing the cost and burden on any given individual source, providing redundancy against system problems, and reducing dependence on the original distributor.”

BitTorrent has been used to distribute copyright material without authorization. It also has a large and growing amount of legitimate use. As previously blogged, P2P at its best is a way for us users to share our disk space and computing power to obtain free or low cost access to data and/or services we want.

In an example of very thorough professional reporting, Peter Svensson, AP Technology Writer, describes what AP found that Comcast was doing to BitTorrent traffic when it followed up on a tip from a Comcast user. The experiment done by AP was to use BitTorrent to transfer copies of the Bible using BitTorrent (they chose the Bible because it is in the public domain so transfer of it is not a violation of anyone’s copyright). Their conclusion:

“Comcast Corp. actively interferes with attempts by some of its high-speed Internet subscribers to share files online, a move that runs counter to the tradition of treating all types of Net traffic equally.

The interference, which The Associated Press confirmed through nationwide tests, is the most drastic example yet of data discrimination by a U.S. Internet service provider. It involves company computers masquerading as those of its users.


Each PC gets a message invisible to the user that looks like it comes from the other computer, telling it to stop communicating. But neither message originated from the other computer—it comes from Comcast. If it were a telephone conversation, it would be like the operator breaking into the conversation, telling each talker in the voice of the other: “Sorry, I have to hang up. Good bye.”“

Note to nerds: The invisible message is an RST packet, part of the TCP protocol. The correct use of RST is documented here by the IETF and does NOT include its use by any intermediary. Electronic Frontier Foundation confirmed the AP results and also provided additional technical information.

Even if we give Comcast the benefit of the doubt and assume they are not influenced at all in their decision of what traffic to block by the fact that P2P protocols like BitTorrent are used to distribute material which competes for precious user attention with the content that Comcast sells, what Comcast is doing is still wrong if not illegal.

The Internet is as fantastically useful as it is because each of us can communicate with each of our friends and get data from any source using any protocol or data transfer method invented or yet to be invented which works on an IP network—I’m simplifying and exaggerating slightly but only slightly. Each of us “sees” the same Internet. Communication becomes much more constrained if each of us sees a different and perhaps incompatible Internet. You can see Google but I can only see Yahoo. I can upload photos to Flickr but you can only upload to dotPhoto. My email can’t get to you; you and I can’t share files (although we can both share with Ellen—today). Gee, almost sounds like mobile phone networks—or cable networks.

I also don’t want anyone or anything masquerading as my computer. Period. If traffic has to be blocked, there are ways to do it without pretending to be me.

Comcast’s reported response was slimy. AP quotes Comcast spokesman Charlie Douglas as saying: “Comcast does not block access to any applications, including BitTorrent.” AP then continues: “Douglas would not specify what the company means by “access”—Comcast subscribers can download BitTorrent files without hindrance. Only uploads of complete files are blocked or delayed by the company, as indicated by AP tests.” Of course in BitTorrent, there has to be an upload for every download.

Contrast the approach taken by Comcast with that taken by Cloud Alliance, a small Vermont wireless ISP which also has to manage its network to assure that some customers don’t hog all the resources. During periods of congestion Cloud Alliance restricts the bandwidth available to all customers. It does NOT try to decide which applications users should run and which they should not. It does NOT spoof being the user’s machine. And it DOES tell the truth about its policy. I know how Cloud Alliance manages bandwidth because the method was described by Michael Birnbaum, who runs the WISP, in a comment on Fractal of Change.

For much more commentary on the Comcast fracas see recent posts on David Isenberg’s blog and a very comprehensive explanation by Susan Crawford.

More on how Cloud Alliance manages traffic is here.

By Tom Evslin, Nerd, Author, Inventor

His personal blog ‘Fractals of Change’ is at blog.tomevslin.com.

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Richard Bennett  –  Oct 30, 2007 3:36 AM

I’m not impressed with this line of attack, and here’s why.

In essence, Tom is repeating the same hollow criticisms that have already been made by the lawyers and wannabe Internet regulators, and they don’t wash technically. We’re not allowed to ascribe paranoia-driven motives to businesses when their behavior is consistent with the rational imperatives of network management, regardless of the suggestions in the old RFCs. Things change on the Internet every day.

BitTorrent is an enormous challenge to ISPs, and the appropriate means to manage it depends on the kind of infrastructure the ISP has in place. I see no reason to swallow the fiction that all networks can be managed by the same weak control procedure (drop and backoff) that was bolted onto the side of TCP in 1986. No reason at all, it’s an article of faith.

I expected better from Tom.

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