Torrent Network

hi friends! in present secnario internet has become the best source for all our day to day activities ranging from study,shoping,entertainment and lots more. you all might be using internet WORLD WIDE WEB(WWW),but do you know that 55% of the traffic of this gaint networking is consumed by a torrent network-- seems amazing?? but its a fact. you all might be downloading songs sharing ebooks etc on internet but heres something you would like to know about new sharing concept.
Files were first exchanged on removable media like CDs,pen drives,etc.. Computers were able to access remote files using filesystem mounting, bulletin board systems (1978), Usenet (1980), and FTP servers (1985). Internet Relay Chat (1988) and Hotline (1997) enabled users to communicate remotely through chat and to exchange files. but the most popular way of file sharing which has emerged is by using peer-to-peer networks, or P2P networks. Some of the most popular networks are FastTrack, Gnutella, Gnutella2 , bitcomet and eDonkey network. With these networks, the one downloads a program to their computer that allows them to connect to the torrent network,called torrent client.some of the most famous clients are Bitcomet,utorrent,limeware,etc. Then with this program the user can search the shared media on other users’ computers and download this media from them across the Internet.it works like a WAN. These networks allow the sharing of any type of content, including songs, games,softwares,ebooks,etc..
literally torrent means -"A large amount of something, especially water or rain; a heavy stream or flow",but in internet terminology it means -"A set of files obtainable through a peer-to-peer network".Torrent protocol is a peer-to-peer file sharing protocol used for distributing large amounts of data.Many of you find it new as there is not much awareness about it in India.like other things even torrent sharing has good and bad aspects.
some Terminology about Torrent network:
Torrent : this refers to the small metadata file you receive from the web server (the one that ends in .torrent.) Metadata here means that the file contains information about the data you want to download, not the data itself.
Peer : A peer is another computer on the internet that you connect to and transfer data. A peer may or may not have the complete file.
Leeches : They are similar to peers in that they won’t have the complete file. But the main difference between the two is that a leech will not upload once the file is downloaded.
Seed : A computer that has a complete copy of a certain torrent. Once a client downloads a file completely, he can continue to upload the file which is called as seeding.
Reseed : When there are zero seeds for a given torrent, then eventually all the peers will get stuck with an incomplete file, since no one in the swarm has the missing pieces. When this happens, a seed must connect to the swarm so that those missing pieces can be transferred. This is called reseeding.
Swarm : The group of machines that are collectively connected for a particular file.
Tracker : A server on the Internet that acts to coordinate the action of Torrent clients.
how does it work??
First, a user playing the role of file-provider makes a file available to the network. This first user's file is called a seed and its availability on the network allows other users, called peers, to connect and begin to download the seed file. As new peers connect to the network and request the same file, their computer receives a different piece of the data from the seed. Once multiple peers have multiple pieces of the seed, BitTorrent allows each to become a source for that portion of the file. The effect of this is to take on a small part of the task and relieve the initial user, distributing the file download task among the seed and many peers. With BitTorrent, no one computer needs to supply data in quantities which could jeopardize the task by overwhelming all resources, yet the same final result—each peer eventually receiving the entire file—is still reached.
After the file is successfully and completely downloaded by a given peer, the peer is able to shift roles and become an additional seed, helping the remaining peers to receive the entire file. The community of Torrent users frowns upon the practice of disconnecting from the network immediately upon success of a file download, and encourages remaining as another seed for as long as practical, which may be days.
This distributed nature of BitTorrent leads to a viral spreading of a file throughout peers. As more peers join the swarm, the likelihood of a successful download increases. Relative to standard Internet hosting, this provides a significant reduction in the original distributor's hardware and bandwidth resource costs. It also provides redundancy against system problems, reduces dependence on the original distributor and provides a source for the file which is generally temporary and therefore harder to trace than when provided by the enduring availability of a host in standard file distribution techniques.

transfer of files via Http protocol VS P2P network

The most common type of file transfer is through a HTTP server. In this method, a HTTP server listens to the client’s requests and serves them. Here the client can only depend on the lone server that is providing the file. The overall download scheme will be limited to the limitations of that server. Also this kind of transfer of file is subjected to single point of failure, where if the server crashes then the whole download process will seize. A single server can handle many such clients and serve the requested file simultaneously to all the clients. The file being served will be available as one single piece, which means that if the download process stops abruptly in the middle the whole file has to be downloaded again.whereas in P2P sharing Each client independently sends a file, called a torrent, that contains the location of the tracker along with a hash of each piece. Clients keep each other updated on the status of their download. Clients download blocks from other (randomly chosen) clients who claim they have the corresponding data. Accordingly, clients also send data that they have previously downloaded to other clients. Once a client receives all the blocks for a given piece, he can verify the hash of that piece against the provided hash in the torrent. Thus once
a client has downloaded and verified all pieces, he can be confident that he has the complete data.in traditional HTTP or FTP protocol the transfer rate will always be limited by the server’s bandwidth. If these servers are flooded with requests then the breakdown and the transaction will terminate. This is not the case in Torrent network since the whole process is not depending on servers alone. The load is distributed across the network between peers and servers. This makes Torrent far better than other methods of sharing.


File sharing advocates
The ethical issues come mostly from the concern that practitioners of file sharing may infringe property rights.
File sharing is not always illegal, even if the works being shared are covered by copyright. For example, some artists may choose to support freeware, shareware, open source, or anti-copyright, and advocate the use of file sharing as a free promotional tool.
Economic impact
The economic effect of file sharing on music revenue is controversial and difficult to determine. Music sales dropped globally from approximately $38 billion in 1999 to $32 billion in 2003, and a number of studies have found that file sharing has a negative impact on record sales.The MPAA had reported that American studios lost $2.3 billion to Internet piracy in 2005, representing approximately one third of the total cost of film piracy in the United States. The MPAA's estimate has been doubted by commentators since it is based on the assumption that one download was equivalent to one lost sale, and downloaders might not purchase the movie even if illegal downloading were not an option.These numbers are further suspicious due to the private nature of the study, which cannot be publicly checked for methodology or validity.On January 22, 2008, as the MPAA was lobbying for a bill which would compel universities to crack down on piracy, it was alleged that MPAA figures on piracy in colleges were inflated by up to 300%.Piracy rates of one-quarter or more for popular software and operating systems are common,even in countries and regions with strong intellectual property enforcement, such as the US or the EU.The pirated software is often distributed through file sharing.
Risks
Researchers have examined potential security risks including the release of personal information, bundled spyware, and viruses downloaded from the network.Some proprietary file sharing clients have included bundled malware, though open source programs typically have not.
Recently, there has been a drastic increase of inadvertent P2P file sharing of personal and sensitive information. This became evident in 2009 at the beginning of President Obama's administration. On February 26, 2009 the blueprints to the helicopter Marine One were made available to the public through a breach in security through a P2P file sharing site. Access to this information has the potential of being detrimental to national security.Two days prior, the Today Show reported that more than 150,000 tax returns, 25,800 student loan applications and 626,000 credit reports were all inadvertently made available though File Sharing.in an attempt to avoid these security leaks, current legislation in the United States is being debated, the Informed P2P User Act. According to this act, it would be mandatory for individuals to be aware of the risks associated with peer-to-peer file sharing before purchasing the software. Informed consent of the user prior to use of these programs would be required. In addition, this act would allow users to block and remove P2P file sharing software from their computers at any time.
file sharing with anonymousity

Anonymous networking technologies have been developed to allow the exchange of data between computers and users in a way that obscures either the user and its network location or the destination of a data access, or both. A popular method is the onion routing concept, prominently implemented in the tor network. Such methods are often used to transfer contentious or illegal material and copyrighted works in violation of legal or acceptable use policies Many current implementations incur high overhead,making them slow or hard to use. However, in locations where very fast Internet access is common, a number of anonymous file-sharing programs have already reached high popularity.Examples of anonymous P2P networks are ANts P2P, RShare, Freenet, I2P, GNUnet and Entropy.
6.1.3 Bandwidth Shaping
Many ISPs don’t encourage the use of BitTorrent from their users. This is because Torrent is usually used to transfer large sized files due to which the traffic over the ISPs increase to a large extent. This has resulted in many file transfer breakdowns across the world.Even our university server forbids it.
References:
http://en.wikipedia.org/wiki/File_sharing