BitTorrents

How exactly does BitTorrent Sharing work?

Answer: Torrent sharing is about "swarming and tracking", where users download many small bits from many different sources at once. Because this format compensates for bottleneck points, it is actually faster than downloading a large file from a single source.

• “Swarming” is about splitting large files into hundreds of smaller “bits”, and then sharing those bits across a “swarm” of dozens of linked users.
• “Tracking” is when specific servers help swarm users find each other.
• Swarm members use special Torrent client software to upload, download, and reconstruct the many file bits into complete usable files.
  
• Special .torrent text files act as pointers during this whole process, helping users find other users to swarm with, and enforcing quality control on all shared files.

Kazaa. BitTorrent is different from the competing Kazaa network in one significant way: BitTorrent is true P2P sharing. Instead of “publisher servers” dishing out files, BitTorrent users do the file serving. Torrent users voluntarily upload their file bits to their swarm without payment or advertising revenue. You could say Torrent users are motivated, not by money, but by a "Pay-It-Forward" cooperative spirit. If you recall the Napster.com model of the 1990’s, BitTorrent swarming is the same, but with sharing incentive added.

Torrent sharing goes like this: if you share files on BitTorrent, you will be rewarded with increased download speed. Conversely, if you choose to "leech" and not share your files upwards, you will be punished with slow Torrent download speeds.

Download speed is controlled by Torrent tracking servers, who monitor all swarm users. If you share, tracker servers will reward you by increasing your alotted swarm bandwidth (sometimes up to 1500 kilobits per second). Similarly, if you leech and limit your upload sharing, tracking servers will choke your download speeds, sometimes to as slow as 1 kilobit per second. Indeed, the "Pay It Forward" philosophy is digitally enforced! Leeches are not welcome in a BitTorrent swarm.


Unlike most P2P networks, however, BitTorrent stands out for 5 major reasons:

1. BitTorrent networking is NOT a publish-subscribe model like Kazaa; instead, BitTorrent is true Peer-Peer networking where the users do the actual file serving.
   
2. Torrents enforce quality control by filtering out corrupted and dummy files, ensuring that downloads contain only what they claim to contain.
   
3. Torrents actively encourage users to share (“seed”) their complete files, while punishing users who "leech".
   
4. BitTorrent can achieve download speeds over 1500 kilobits per second.
   
5. BitTorrent code is open-source, advertising-free, and adware/spyware-free. This means that no single person profits from BitTorrent's success.

Torrent networking debuted in 2001. A Python-language programmer, Bram Cohen, created the technology with the intent to share it with everyone. And indeed, its popularity has taken off since 2005. Although its user base and variety of available files is smaller than the Kazaa network, the torrent community is growing exponentially. Because torrents screen out dummy and corrupt files, are free of adware/spyware, and achieve amazing download speeds, torrent popularity is growing fast. At its current rate of growth, BitTorrent networking will become the largest true P2P file-sharing community within the next year.