BitTorrent's Creator Bram Cohen Interviewed

Delta-9 writes "The New York Times has this interview (free reg. req.) with Bram Cohen, the author/creator of the widely popular BitTorrent p2p application." Talks a bit about BitTorrent, its implications, but also a lot about Bram himself. Interesting piece.

Comments

Pretty Cool

[pmaccabe]

BitTorrent is a nice creative alternative solution to what has generally been a Napster knockoff syndrome among P2P services.

Re:Pretty Cool

[Ed Avis]

When will someone combine bittorrent and rsync? That sounds like the best way to upgrade from Fedora Core 2 test1 to Fedora Core 2 test2, or to update your Gentoo source tree.

Amazing...

[blorg]

"...when he was developing the system, he said, widespread copyright infringement was not what he had in mind [...] BitTorrent really started to take off in early 2003 when it was used to distribute a new version of Linux [...] Using BitTorrent for illegal trading, he added, is "patently stupid because it's not anonymous, and it can't be made anonymous because it's fundamentally antithetical to the architecture."

...a *balanced* article, in the mainstream media, about a p2p app, which concentrates on the technology behind the app, and the possibility of non-infringing uses.

Now I've seen it all.

Good Days Already Gone

[aerojad]

The school I go to has already ended the party, limiting the crap out of BT connections, so my speeds dropped from 500-600k/sec to 3-4k/sec for each torrent. What's the speed something has to drop to so that driving to where the server is, burning a cd, and driving home is faster than the download itself?

Any other schools out there get a similar clampdown?

Re:Good Days Already Gone

[C10H14N2]

A car leaves Los Angeles for San Diego at 60mph, stops in San Diego for fifteen minutes and returns by the same route at the same speed. If a single CD-R has the capacity for 700 million bytes and a byte has eight bits, roughly 5.6 billion bits in total, how many bits per second would you require to transfer those bits in 15,300 seconds? Answer: 366kbps.

If each 1Mb/s/month of bandwidth costs $500 and one hundred people want to download CDs as quickly as a 240 mile round trip on a constant basis, how much bandwidth would be required and what would it cost? Answer 36Mb/s at a cost of $216,000 per year.

Any guesses why they're throttling you?

BT is awesome, keep it that way.

[zoloto]

For his part, Mr. Cohen pointed out that BitTorrent users are not anonymous and that their numeric Internet addresses are easily viewable by anyone who cares. "It amazes me that sites like Suprnova continue to stay up, because it would be so easy to sue them," he said. Using BitTorrent for illegal trading, he added, is "patently stupid because it's not anonymous, and it can't be made anonymous because it's fundamentally antithetical to the architecture."

That said, Mr. Cohen is not in the nanny business.

"I'm not going to get up on my high horse and tell others not to do it because it's not my place to berate people," he said. "I just sort of watch it with some amusement."

as well he shouldn't berate people for their usage of his software. neither should you. ..

and what's this bit about the MPAA having BitTorrent on their radar screen??? give me a break! try the piracy and other infringement sources because the authors do not promote it, regardless of what they know is happening with their software.

Re:BT is awesome, keep it that way.

[Anonymous Coward]

That's actually wrong. Anonymous p2p can be this fast, in spades.

We have an anonymous Bittorrent client in experimental testing right now, just to test our anonymous p2p overlay; it's not much slower - it's surprisingly fast given our rocky, big, test environment, and a great test of our overlay.

But BT has a critical flaw, which is that centralised tracker. It can still be slashdotted, rather easily (BT places an immense load on a server compared to http; the limit with BT is the CPU and/or RAM, not the bandwidth). In actual fact it doesn't scale well, but it could be extended with a distributed hashtable like Kademlia (which, for example, Overnet and the Emule test-client use) and some other sub-protocols; the tracking could be fully distributed. Additionally, the time taken to reach one distributed copy could be reduced, and the general performance almost doubled by using a (better) block selection algorithm (I will leave that as an exercise to the reader).

And no, I won't tell you who we are. We won't be ready for slashdotting for about six months or so; unlike mute, we aren't going to publish shit before it's ready and call it anonymous. Some people's livelihoods, well-being, privacy and in some cases lives rely on the ability to communicate freely; that's an important responsibility to be charged with, too important to label buggy quarter-written code as usable. :)

Should be used for Linux Distributions

[mcrbids]

As I sit here, getting packages at a mightily slow 8 k/sec via Fedora's Red Hat Network, I wonder why this must be.

Why don't tools like yum, up2date, and apt incorporate BitTorrent concepts to download packages and files?

If there was an option when installing Fedora or Debian to "share XX Mbytes at YY kbps" I'd be perfectly happy to donate 50 MB of disk space and 5-10 Kbps of bandwidth to the cause. That's be anough to reliably provide a few packages for redistribution.

Multiply that by the number of Linux installs, and you have a lightning-quick package delivery system.

Imagine apt-get or up2date ALWAYS able to saturate your broadband connection when doing an update!

Why is nobody doing this? Security isn't an issue, since BT uses SHA1. Source isn't an issue since BT is open source. Isn't the RHN stuff already written in PYTHON?!?!?

Re:Should be used for Linux Distributions

[Weird O'Puns]

As Bram stated in this article, Bittorrent was designed for big files. Most software packages aren't that big so BT won't really be ideal solution for this. I think I read somewhere that it will actually cause more problems it might soleve.(But I'm not 100% sure about this as I haven't studied inner workings of BT that good)

Don't get me wrong. I would love to have somekind of way to share my packages. I just don't think BT is an ideal solution for this.

Compiled client for linux

[Via_Patrino]

I think a problem in BT is the lack of compiled clients for linux. Phyton is big and an interpred code can eat a lot of cpu time specially when handlig several connections at a time. I've seen a c++ client for linux but it isn't developed anymore.

Another problem is bandwidth limitation not included in the software, you can use an external program like trickle (heavy) or the kernel, but that way it doesn't share bandwidth equally between users, it shares very bad indeed.

Other is that eventually I want to share my bandwidth but don't want to download the whole file (don't have time/space). I may use some trick (download a part of it and after that limit my download rate) but I don't think that's the best solution.

Re:Compiled client for linux

[mcrbids]

I think a problem in BT is the lack of compiled clients for linux.

But that isn't a problem, really. I've used BT quite a bit on Linux. You can limit the # of uploads and the upload bandwidth. Presumably, with ulimit or something similar, the same could be done for CPU/RAM.

If I allowed 10 connections, 50 MB of disk space, and 10 Kbps maxupload, even using Python, it'd run much less than 5% CPU time of my dedicated 600 Mhz celeron router/firewall system. I'd never notice 10 Kbps on my 1500/384 DSL. Yet, if thousands/million of people offered meager numbers like this to the world, getting package updates would be a SNAP.

Assume that in my 50 MB of cache disk space were 5-10 packages. Heck, the way BT works, the files don't even need to be complete files! I could, for example, share parts of the Kernel package. Have the files being shared in my cache be based on popularity - so that more popular files get cached in more servers, and rotate out the less popular ones.

With a system like this, the everybody on earth could conceivably update their systems simultaneously and everybody would *still* get a decent amount of bandwidth.

The only issue is that there are trackers capable of handling that many connections, but this problem pales when compared to trying to do it all with FTP,

Interesting point

[mwheeler01]

The article makes an interesting point that I'm sure a number of /. users are aware of that bittorrent is not anonymous at all. Many less technically savy users made that mistake when using Napster and Kazaa and got screwed by the RIAA. Now while you're uploading and downloading you have no control over who sees your IP but I'm curious to know if trackers hold on to this information after you disconnect, or if sites like suprnova.org keep track of who downloads what torrent. Does anyone have some insight into this?

Re:Interesting point

[swilver]

None of the file sharing tools currently available provide any kind of anonymity. You may be anonymous while browsing for files and doing searches as these usually flow through somekind of distributed network, but once the downloading (or uploading) starts the other side will know who you are as they have your IP address.

The main reason for this is lack of bandwidth. If you want anonymity even while downloading, someone else will have to act as an intermediary (preferably more than one). Those intermediaries though will have to download some data, and then upload it again to you which gains them nothing (in other words, it wastes a lot of bandwidth). Everyone will need to provide some bandwidth for this purpose to make this even remotely feasible.

Only Freenet currently does this that I'm aware of, and it's a lot slower for that very reason. Bandwidth however seems to be subject to Moore's law; soon there should be plenty of it, and then you can have real anonymity.

Re:Interesting point

[Anonymous Coward]

Only Freenet currently does this that I'm aware of, and it's a lot slower for that very reason. Bandwidth however seems to be subject to Moore's law; soon there should be plenty of it, and then you can have real anonymity.

Winny, a P2P based on Freenet is currently being used extensively by Japanese sharers. Namely for HDTV caps and DVDiso's. The node system makes it that if fast access to "better files" is desired, more bandwidth will have to be contributed since only certain nodes have those files you want (in the beginning). This somehow guaruntees there are bandwidth for files with popularity.

Irony of timing

[Supp0rtLinux]

How perfect... I had just stumbled across this article which mentions BitTorrent and has some interesting insight on legally circumventing the RIAA.

Evil genius

[b1t r0t]

For his part, Mr. Cohen pointed out that BitTorrent users are not anonymous and that their numeric Internet addresses are easily viewable by anyone who cares.

The evil genius of the whole BitTorrent idea is the lack of anonymity. Like the article points out, it's perfect for Linux distros and anime fansubs. But if you think nobody can know what you're sharing or who you are, you're a fool.

I use the Mac OS X version, so I don't get to see this, but a friend showed me his Windows version and you could not only see who was connected, but what their bandwidth use was too. Apparently some people know how to become super-leeches. They'll appear, and everybody else's download speed suddenly goes to zero while they suck up the whole file. Then they go away. That this is even visible to a regular client should be thought-provoking.

It took me months to find it (because nobody bothered to document it!), but fortunately I found the bandwidth limiter in the OS X version. (Click on that widget on the right side of the window title bar.) Now I can seed files without completely hosing my DSL connection.

The thing I think I like most about BitTorrent compared to other "forced sharing" models like Napster is that you get to choose what you want to share. You go to a tracker and see "hey there's no seeds on that one show I like", then share the file at 5K. That way even the leeches have to wait. Animesuki.com even has a "seeds needed" page for anything that's worse than about 10 or 15 to zero.

I love bittorrent

[larry bagina]

When I first tried bittorrent (win32 version), I scoffed at the "donationware" nag. Yeah, sure, I'll pay money for a p2p tool. Not!

But then a funny thing happened. I found a tracker for trading live shows from various bands in flac/shn format. Since then, my usage of blank CDs has increased dramatically. So I've decided to share the money and donated to Bram and the tracker.

Re:guilt

[TobySmurf]

I know how you feel, I did the same a few months ago when I realized that he had completely solved all my Gentoo download woes. You must admit though that it feels good to send him $20, especially seeing as probably only one person in 50000 gives him anything. Bram, if you lived here in Calgary I would buy you a beer or five any day...

Re:What about... registering?

[Anonymous Coward]

If they're like me, they did in fact register - and forget about it. There's so many people registered there that thinking up a nick that hadn't been taken, and that I'd be able to remember on the every month or two that I'd want to read their story, that I've registered and forgotten passwords or user names at least three or four times. I've got so many passwords to remember for work, school, and home allready that even this one more is past the point of saturation for my brain.

Re:technology is what it is

[Anonymous Coward]

On my ADSL connection, I would start bittorrent from the command line to limit each torrent's upstream bandwidth to 1k. I would often get 50-100k downloads because bittorrent's tic-for-tac system doesn't work on ADSL. It's good to limit uploads anyway if you don't have anything in place to prioritize null ACKs.

ISP caps

[tepples]

if you limit your upload rate, other peers will lower their upload rate to you.

What if I care more about the reliability of my residential cable Internet connection than about download rate? It seems that if I sustain more than about 20 KBytes/s for too long, Comcast interrupts my connection for a few minutes.

Re:Dear Bram,

[HTH NE1]

Please make a "no uploading" option button on BitTorrent, because I am a leech, signed the Kazaa masses.

Technically, there is no uploading with BitTorrent at all. Everyone downloads from everyone else. The only real upload is the uploading of the initial .torrent file to a public webserver, and even that can be not an upload if you serve it from a webserver on your local machine or otherwise created on the server without transferring the actual .torrent file.

User interfaces should use terms relative to the user. While one could argue that the computer is uploading, the user is not. Without defining the subject performing the act, the words "upload" and "download" are ambiguous. The subject performing the upload or download is that entity that, barring its action, the transfer would not take place.

I've hacked my own client to use more appropriate terminology: "Incoming" instead of "Download" and "Outgoing" instead of "Upload".

The dilution of the words to make it so every download has an equal and opposite upload and vice versa serves only to make people liable for the actions of their machines under control by outside forces.

Failing to secure ones property against theft should not be (facilitating) a crime whether it is files on a server, a pie on a windowsill, or a car left running unattended.

Severe BT bottleneck: trackers

[NineNine]

At first, when I found BT, I was thrilled (once I figured the damn thing out). But now, I'm noticing that more and more trackers are bogging down, so even with hundreds of "leechers" and several "seeds", speeds can hover anywhere from 1-5KBps. That, and frequent tracker errors point out that trackers are apparently very resource intensive and can get bogged down quickly. Does anybody know if BT trackers are due to be improved any time soon? Many, many, many links on suprnova.org, point to trackers that are already swamped or dead, making BT not much better (or worse) than straight FTP.

Re:Free Reg... blah.. blah...

[essreenim]

Yeah,

I wonder how much the NY times pays people to blog over them...

Re:Not intended to be used for illegal distributio

[MrAngryForNoReason]

BitTorrent is used extensively for distribution of new game demos and game/movie trailers. It is perfect for anything that has high first day demand. It is no more suited to illegal file trading than ftp, http or any other protocol.

They mention Suprnova in the article but not Filerush or any of the other hundreds of sites offering torrents of legally shared content. I mean torrents of media are posted all the time on /. after hosting servers buckle under the strain.

Why do people always jump on the infringing uses of software and try and make out like that is the whole story.