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Just in case the server dies

BitTorrent packets are marked as bulk data to make traffic shaping easier

Read the release notes of the latest version from
http://www.bittorrent.com/bittorrent_versions.html

According to the BitTorrent Protocol FAQ, this is incorrect:

Downloaders generally download pieces in random order, which does a reasonably good job of keeping them from having a strict subset or superset of the pieces of any of their peers.

From The Official BitTorrent Home Page:

What is BitTorrent?

BitTorrent is a free speech tool.

BitTorrent gives you the same freedom to publish previously enjoyed by only a select few with special equipment and lots of money. ("Freedom of the press is limited to those who own one" -- journalist A.J. Liebling.)

You have something terrific to publish -- a large music or video file, software, a game or anything else that many people would like to have. But the more popular your file becomes, the more you are punished by soaring bandwidth costs. If your file becomes phenomenally successful and a flash crowd of hundreds or thousands try to get it at once, your server simply crashes and no one gets it.

There is a solution to this vicious cycle. BitTorrent, the result of over two years of intensive development, is a simple and free software product that addresses all of these problems.

The key to scaleable and robust distribution is cooperation. With BitTorrent, those who get your file tap into their upload capacity to give the file to others at the same time. Those that provide the most to others get the best treatment in return. ("Give and ye shall receive!")

Cooperative distribution can grow almost without limit, because each new participant brings not only demand, but also supply. Instead of a vicious cycle, popularity creates a virtuous circle. And because each new participant brings new resources to the distribution, you get limitless scalability for a nearly fixed cost.

BitTorrent is not just a concept, but has an easy-to-use implementation capable of swarming downloads across unreliable networks. BitTorrent has been embraced by numerous publishers to distribute to millions of users.

With BitTorrent free speech no longer has a high price.

Is this a joke? BitTorrent is suddenly a "free speech tool"?

What, no one is going to talk about the new BitTorrent Open Source License that has been slapped on this 4.0 version?

Thoughts about this would be much appreciated. I'm reading through it right now.

• License has changed to the BitTorrent Open Source License

I hate people who invent their own licenses. And this one is completely unintelligible, even the preamble is written in lawyerspeak.

This pretty much guarantees I won't ever touch the code: I don't have a clue what I'm allowed, not allowed, and required to do. The GPL and BSD-like licenses are at least understandable for a non-lawyer.

Dear Lazyweb:

This version of bittorrent is licensed under the BitTorrent Open Source License. Could you please compare and contrast this with other open source licenses for me?

Thank you, Lazyweb.

Is it just me... but does anyone else find it ironic that there isn't a torrent available for downloading Bittorrent?

The actual link is to the download is here.

The changelog:

# 2005-03-07: 4.0.0 is now available.
Changes since the last stable release:

All new queue-based user interface Many options are now modifiable from the interface, including upload rate Lots of other interface improvements Extra stats are visible, for those who like it Remembers what it was doing across restarts New .torrent maker "btmaketorrentgui" replaces "btcompletedir" Better performance, as always License has changed to the BitTorrent Open Source License Torrent fields are correctly created and interpreted as utf8 Too many little things to list

A few technical notes, for those interested:

Single port: launchmany can seed and client can download many files from a single port and thread Interface now uses GTK instead of wxWidgets BitTorrent packets are marked as bulk data to make traffic shaping easier

All new queue-based user interface

Many options are now modifiable from the interface

Lots of other interface improvements

Extra stats are visible, for those who like it

Remembers what it was doing across restarts

New .torrent maker "btmaketorrentgui" replaces "btcompletedir"

Better performance, as always

License has changed to the BitTorrent Open Source License

Torrent fields are correctly created and interpreted as utf8

Too many little things to list

Single port: launchmany can seed and client can download many files from a single port and thread

Interface now uses GTK instead of wxWidgets

BitTorrent packets are marked as bulk data to make traffic shaping easier

All new queue-based user interface

Many options are now modifiable from the interface

Lots of other interface improvements

Extra stats are visible, for those who like it

Remembers what it was doing across restarts

New .torrent maker "btmaketorrentgui" replaces "btcompletedir"

Better performance, as always

License has changed to the BitTorrent Open Source License

Torrent fields are correctly created and interpreted as utf8

Too many little things to list

Single port: launchmany can seed and client can download many files from a single port and thread

Interface now uses GTK instead of wxWidgets

BitTorrent packets are marked as bulk data to make traffic shaping easier

http://www.bittorrent.com/

You're welcome. On a sidenote: the official BT homepage has a new look! When did that happen. I figured the site with Bram Cohen's photo prominently placed (upper left edge, was it?) would last forever...

On a more serious note, the actual torrents are linked to elsewhere in this story's comments. There are also downloads on SF.net which might be faster.

It's not a question of the giga part, everyone knows the metric system by now (I hope)

Really, do you? Last time I looked, G or giga is defined as exactly 10^9 (1,000,000,000).

Here's the important part you were ignoring:
---
Hard drive manufacturer: One GigaByte = 1000 bytes

Wrong. Hard drive manufacturers and everyone else who knows how to use SI prefixes correctly knows that one gigabyte is 1,000,000,000 bytes.

Software/everyone else: One GigaByte = 1024 bytes

Wrong again. If in this case you mean 2^30 bytes, 1 GiB = 1,073,741,824 bytes. What about network people? To them, 1 GB is certainly 1,000,000,000 bytes. Does a 100 Mb/s Ethernet operate at 1,000,000 bits per second (10^6) or is is 1,048,576 (2^20)? More and more people are becoming aware of this issue and moving from the old ambiguous use of prefixes representing powers of ten to represent powers of two to the new more percise and seperate binary SI prefixes. Case in point. Bittorent. Download the client, use it, and you'll notice that bytes, in binary multiples are correctly refered to as KiB, MiB, etc.

If you had actually read the link I posted on SI prefixes for binary multiples, you might know the following historical context:

Once upon a time, computer professionals noticed that 2^10 was very nearly equal to 1000 and started using the SI prefix "kilo" to mean 1024. That worked well enough for a decade or two because everybody who talked kilobytes knew that the term implied 1024 bytes. But, almost overnight a much more numerous "everybody" bought computers, and the trade computer professionals needed to talk to physicists and engineers and even to ordinary people, most of whom know that a kilometer is 1000 meters and a kilogram is 1000 grams.

Then data storage for gigabytes, and even terabytes, became practical, and the storage devices were not constructed on binary trees, which meant that, for many practical purposes, binary arithmetic was less convenient than decimal arithmetic. The result is that today "everybody" does not "know" what a megabyte is. When discussing computer memory, most manufacturers use megabyte to mean 2^20 = 1 048 576 bytes, but the manufacturers of computer storage devices usually use the term to mean 1 000 000 bytes. Some designers of local area networks have used megabit per second to mean 1 048 576 bit/s, but all telecommunications engineers use it to mean 10^6 bit/s. And if two definitions of the megabyte are not enough, a third megabyte of 1 024 000 bytes is the megabyte used to format the familiar 90 mm (3 1/2 inch), "1.44 MB" diskette. The confusion is real, as is the potential for incompatibility in standards and in implemented systems.

Faced with this reality, the IEEE Standards Board decided that IEEE standards will use the conventional, internationally adopted, definitions of the SI prefixes. Mega will mean 1 000 000, except that the base-two definition may be used (if such usage is explicitly pointed out on a case-by-case basis) until such time that prefixes for binary multiples are adopted by an appropriate standards body.

In December 1998 the International Electrotechnical Commission (IEC), the leading international organization for worldwide standardization in electrotechnology, approved as an IEC International Standard names and symbols for prefixes for binary multiples for use in the fields of data processing and data transmission.

That defeats the purpose of BitTorrent, and it's selfish. You can throttle the upload speed in Azureus (and others) quite easily, but expect your download speed to suffer. A limited or outright lack of contribution unfairly penalizes others trying to get the file, who are quite willing to seed. Go and read the introduction to how BitTorrent works, and you understand why everyone needs to seed for BitTorrent to work effectively for everyone.

If you can't handle helping to seed the torrent, then go download it from one of the overloaded HTTP mirrors.

Who stole what from who?

Ignoring that copying is not stealing in any normal sense of the word, he didn't copy anything.

In fact:

There, I just committed a crime on par with the crime in question. I linked to a place that could allow you to obtain infringing material.

do Macs support torrents natively

Yes.

You can find the license from the beta tarball

The "BitTorrent Open Source License", in its own words, seems to be derived from the Jabber Open Source License.

You know, kinda like bittorrent?

Perhaps you should try this?

Hm, more seriously.. They must really have tried to make something special. Otherwise WebDAV+SSL would have proven to be a bit cheaper.. :)

Mods, read the whitepaper if you must and mod this guy up!

BitTorrent does cryptographic hashing (SHA1) of all data. When you see "Download succeeded!" you can be sure that BitTorrent has already verified the integrity of the data. The integrity and authenticity of a BitTorrent download is as good as the original request to the tracker. Checking the MD5/CRC32/other hash of a file downloaded via BitTorrent is redundant.

The Official site has everything in detail.

From the man himself:

4. Generate a metainfo (.torrent) file using the complete file to be served and the URL of the tracker.

So, a .torrent file could be considered a derivative work of the file to be served, so to speak. Thus, it could be reasonable to believe that they have copyright on the .torrent. Or, as my feeble understanding of the law leads me to think, producing a .torrent (a potential derivative work) of a copyrighted file without the owner's authorization is illegal in and of itself.

Has Sony learned nothing from its newest and closest competitor?

FAQ it's under the MIT license rather than in the public domain. Not that it makes much of a difference, of course.

Anyone who knows anything about social psychology is apt to have a very low opinion of it :) Whatever norms have evolved out BitTorrent usage are products of conscious design decisions made by Bram Cohen. In particular, BT employs a very rudimentary game-theoretic model to ration upload bandwidth. Basically what makes it so much better than other P2P apps is that the no-leeching constraint is enforced at the software level. Still, you are right that the largest BT communities (SuprNova et al.) still rely heavily of altruism in the form of seeders. For this reason alone I am highly suspicious of the network's long-term feasibility. There is simply no benefit to me for seeding, even though it has positive externalities in the form of the continued existence of the network. As soon as the masses get ahold of it (the latest round of lawsuits should help), things will go to the dogs.

the original didn't have upstream limiting

By "original", I didn't mean the very first release, but rather releases from the original creator of the BT protocol, Bram Cohen, as opposed to the much-more-elaborate reimplementations. I have no idea when he added the rate limit.

It is a centralized P2P file sharing protocol, whereas you download a torrent file, and it contains information about the file and more importantly the address of a tracker. All of the other people that have downloaded the complete file all connect to the tracker, these are known as seeders. The tracker tells your BT client who has the file you are requesting and what their address is. And besides you didn't try the obvious?

Just Google it or have a Torrent ready and redirect people here.

Bram Cohen's BitTorrent should give you some hope.

...that's only if the servers arn't flooded...

Sounds like a good reason to use Bittorrent.

People haven't learned about Bit Torrent yet?!?

From bittorrent.com

"The tracker is receiving information from all downloaders and giving them random lists of peers."

The tracker is how you normally get other people's IP addresses, no compromise necessary. You won't necessarily get all the IP addresses, but if you have multiple clients at once constantly connecting, you'll get almost all of them. The real question is why don't trackers use blocklists for the *AAs.

Go give him some money so he can do more cool stuff for us!

the guy honestly looks like Bram Cohen.

Being associated with Bittorrent doesn't get you the chicks... the non-digital ones, anyway ;-)

Well... it will continue to grow quite as is for a few more years... Until all pda's and cell phones are internet ready (without wifi hotspots)...

Then we are going to see in our more globally minded futures as information becomes centralized into a few trusted? areas.

While it will still be used for entertainment.

But I do believe that a globalization and releasing of files online will continue to grow with my bandwidth ;-)

You can get most popular shows via BitTorrent. Check out this great site for a listing. And check out Azureus if you're looking for a great client!

...since it's a 259 MB download.

What a perfect (and missed) opportunity for NASA to use BitTorrent instead of a huge zip file. Ah well.

I love BitTorrent, it maxes out my cable modem at 200 down, 30 up; no other method of downloading can fill the pipe.

The only problem is the reliability of certain sites with content -- which I'm sure you have no relationship with; but if BitTorrent could piggyback off Freenet, it might go a long way toward improving the stability of these sites.

Also, are you going to do anything with the bittorrent.com site? (That's the one Mozilla "suggests" first when I start typing "bittorrent" in the URL bar.)