BitTorrent
Join the swarm!
BY: Joe Petruska
What is BitTorrent?
a peer-to-peer file sharing protocol used for
distributing large amounts of data
Who? What? Where? When?
- Invented By Bram Cohen
- Released July 2001
It is now maintained by Cohen's company,
BitTorrent Inc.
What is BitTorrent used for?
Content Distribution
- Music (new artists, bands, etc..)
- Movies (independent film makers, public service, etc..)
- Podcasting
Commercial Use
- Game Patching Systems (World Of Warcraft)
- Programs (Linux, BEoS, etc...)
How BitTorrent works.
Seeds:
- Host Files
- Distribute to peers
- Determine the speed
of the download
The more seeds a torrent has the faster the transfer generally
will be.
How BitTorrent works.
Peers:
- Download Files
- Distribute to peers
The more peers a torrent has the more availability the torrent
will have as a whole.
How BitTorrent works.
Trackers:
- Delegate transfer speeds
- Keep Tabs on transfers
- Block Banned users
- Block peers from abuse
- Verify content availability.
The tracker is the back-end server required for a BitTorrent
transfer.
How BitTorrent works.
DHT:
- Distributed Hash Server
- No back-end Tracker
- Blocked by private
and secure trackers
- Less taxing on servers
- Increased peer security.
A DHT tracking system does not require a Tracker. This leaves
it in the hands of the peers, and no real way check swarm life.
or delegate who gets what.
Problems with BitTorrent.
Leechers:
- Steal bandwidth from seeds
- Do not contribute to the swarm
- Ultimately kill torrent life
Torrents are only as healthy as their availability.
A leech kills the life span and speed
by not sharing with other peers.
Problems with BitTorrent.
Copyright:
- Many things not legally distributed
- Movie and Music industries very mad
- Unsuspecting users targeted
for lawsuits.
With the growing popularity of BitTorrent
the Music and Film industries of America (RIAA / MPAA)
have targeted unsuspecting downloaders and hit them with
fines and lawsuits.
BitTorrent Clients.
Clients:
- BitTorrent
- uTorrent
- Azureus
- BitTyrant
- Transmission
- Limewire
There are clients for Mac, Windows, and Unix
Most are Free and Open Source.
Tech Specs.
Downloading:
- Segments
- "Rarest first" scheme
- "flash crowd" resistant
- More overload and abuse proof then
other file distribution methods. (FTP, HTTP)
Since each peer receives a small amount of the "rarest data" it
can then distribute it to another peer. The lack of a central
server makes it ideal for large file distribution. Also, the load
required by the server is greatly reduced.