The idea of peercasting plays an important role in the 4th generation of peer to peer file sharing networks, as it allows for a node to broadcast multiple live streams of data at the same time. The reason peercasting has been introduced into the 4th generation of peer to peer networks is for the simple fact that many downloaders wish to be able to preview a file as it is being downloaded. Due to the nature of peercasting, since it is basically a live stream, one can preview as he/she is downloading the file regardless as to whether it is a video or music file.

There have been a number of issues associated with the development of peercasting, most of which has to do with the connections themselves. In order to counter these connection issues which has plagued the peercasting networks, the concept of substreaming was developed into the networks. In all basic form, what happens is that when one node is peercasting, their client is actually sending out multiple simultaneous broadcasts of the same file, but to different nodes, this way if a connection is lost or rerouted, the stream can still be found again allowing the user to pick up the download where it was left at when the connection changed.

One of the most common forms of streaming peer to peer file sharing networks is that of the CoolStreaming network which allows a user/node broadcast a television show, thus the term peer to peer TV or for simplicity P2PTV. There are currently over 1 million users of this P2PTV form of file sharing.

In general however, the concepts of the peer to peer network have stayed the same, only the actual protocols have changed. When speaking about the tree structure of the 4th generation of peer to peer file sharing network, one must look at the older generations for the answer. Quite simply, most of the 4th generation of peer to peer file sharing protocols follow the same basic tree structure as the bit torrent protocol due to the fact that this network has already proven time after time to be one of the most stable peer to peer network as of date. The use of multiple nodes in which some nodes are considered as more than equal make connections to newer nodes as they connect and search for one of these super nodes. It is these super nodes that will then route all incoming as well as outgoing connections for the client in order to ensure that the network will not bottle neck.

Popularity: 11% [?]

The concept of the swarm structure of a peer to peer file sharing network has stayed a constant since the 2nd generation of peer to peer file sharing protocols. When a use wants a file, they will go to a website and look up the file that they are in search of and download the tracker or .torrent file. From this point, the peer to peer file sharing client then connects to the URLs in the torrent tracker files and begins to make connections with various nodes around the world who have part or all of the file in question. The minute the client starts to make connections to other nodes or computers, then then join the swarm for that particular file. In general, the peers in the network, or leechers will trade file parts until they both have all of the pieces, or until they both are lacking certain pieces. It is only at this point that a client or node will begin to download directly from a seed.

It is for this reason that while downloading a file, you may be connected to multiple seeds for the file in question but may not be downloading directly from them. It is the basic hierarchy of the protocol which states the rarest files first. The main reason for this is the simple fact that seeds, especially the original seeder, should by now already shared a substantial amount of the file during the download itself. Because they have most likely met the basic share ratio of 1.5 to 1 they no longer need to be part of the general population of the swarm and instead, only give out pieces when there are none available, which technically should never happen.

This type pf hierarchy on the network is usually very efficient, except in the cases where certain nodes may choose o download certain files in certain orders. Although by default, a user is forced to download based on the rarest first protocol, due to the customizability of the particular peer to peer file sharing client, any user can choose which files to download in which order. A use can even decide to not even download certain portions of a file, or may choose to give higher priority to certain bits of file data based on how the file was broken down by the original seeder.

When we talk about the swarm structure of the 4th generation of peer to peer file sharing networks, we have to go no farther than the previous generations. The previous generations of peer to peer file sharing networks have mainly focused on perfecting the structure of the file sharing networks, while the 4th generation began its focus on the one request that has been asked for since the 2nd generation which is the ability to preview the download as it is happening. Since newer technology and faster internet connections have become available, the ability to live stream a video of virtually any size has now been available making it a priority to the file sharing networks.

Finally the out cry for a previewable download in the peer to peer file sharing industry. This is not the first time that previews have been available as it was actually introduced in clients like Ares back in the 3rd generation, but was not very efficient at the preview process as it had a habit of jumping from piece of data to another piece leaving a virtually indistinguishable preview especially on smaller files.

Popularity: 16% [?]

It was 2005 when Gnutella was the third largest file sharing protocol in the world. Even today, Gnutella maintains their rank as the third largest regardless of the fact that FastTrack has declined and the bit torrent protocol has taken over. Gnutella was first developed back in 2000 right after Nullsoft was bought out by American Online. When the program was finished, its release date was announced on Slashdot and the first day it was available, people swarmed the site to download he client applications which were open source.

Due to the fact that AOL now owned Nullsoft, the day after the public release, American Online stopped the project completely due to the possibilities of legal implications. Thanks to the fact that this was released as an open source program, that one day was all that was needed. Within a matter of weeks, the program was reverse engineered and re-released as open source clones. All maintaining the original protocol developed for the Gnutella network.

It was in 2001 when Napster was hit for legal issues, many people left Napster as soon as they found out and chose an alternative. The number one alternative they chose was to use the Gnutella cloned clients. It was because of these Napster refugees, that the Gnutella network discovered its weakness when the entire network began to bottleneck, but thanks to the newly developed FastTrack, Gnutella was redeveloped to include their ultrapeer protocol which prevented future bottlenecks in the network.

By 2001 and 2002 both LimeWire and Morpheus were using the open source Gnutella protocol in their networks as it allowed for a semi-centralized network versus the fulle decentralized bit torrent protocol.

The difference betweek Gnutella and the bit torrent protocol, is that when a client side node is booted up, it searches for ultrapeers. Ultrapeers are nodes that maintain the information of other clients in the network. Basically an Ultrapeer is a client that is never shut down and therefore has a complete list of nodes in the network. It will then try to connect to a certain number of these nodes in the network until it reaches its quota of connections.

Once it makes those connections and compiles it own list, it then takes over the position of the ultrapeer, but only to those node in which it is connected to. Basically a first come first serve basis. The fist node online helps the other nodes connect to each other. From there, in order to build up the database of files, one client would d a search. In this search function, their client contacts only the nodes that they are connected to requesting that file, the nodes it is connected to then forwards the search to the nodes in its connection. Eventually the search goes through the entire network and the number of available sources is slowly reported back to the requesting client application.

Gnutella has come a long way and still maintains its standings in the peer to peer file sharing networks. P2P is here to stay and it is not going anywhere, so regardless of the program and protocol you choose, you are bound to find what you want.

Popularity: 6% [?]

In 2003, the latest peer to peer file sharing protocol was WASTE which had been developed by Justin Frankel who worked with Nullsoft. The name of the protocol was actually decided based on a novel that was written by Thomas Pynchon that was entitled The Crying of Lot 49, in which their was an acronym of the same which stood for “We Await Silent Tristero’s Empire” and was an underground postal service in the novel. In the same way, WASTE is an underground postal service designed to deliver data rather than mail, but it has the same effect of being underground and a means of delivering something.

Right after the development of WASTE, Nullsoft was bought out by American Online. During the initial release of WASTE, the parent company, AOL, realized the possibilities of legal implications and pulled the release from the website. Luckily, since WASTE was an open source project, those who downloaded still made it available long after AOL had attempted to stop the distribution. It did not take long for the source code of WASTE, to get reverse engineered and implemented into many other peer to peer file sharing clients that are still available today.

Since the time when American Online pulled the release of WASTE, many of the original development team has gathered to covertly maintain the protocol in which the only true source of this project is still available in its originality at Source Forge. Source Forge is the home to many of the open source peer to peer file sharing clients. Thanks to Source Forge, these open source projects can stay open source since there is no cost to the developer. For a long time, many have believed that the internet should be free and anything within its domain should be conformed with this belief. It is with this idealism that many of the internets best software is open source and can even be found there at that site.

WASTE offers many of the same features that virtually any peer to peer file sharing protocol and client share, but is an anonymous client with built in chat capabilities. Chatting has always helped during the downloading process. There is an entire community of people out there who enjoy using the peer to peer file sharing clients and some are always looking to talk about their hobby. Feel free to start a chat will a fellow file sharer and keep the internet free.

Popularity: 5% [?]

There are many peer to peer file sharing protocols out there and even more variations of the original open source code, many of these are anonymous, while still many are not. One of the anonymous peer to peer file sharing programs out there is known as ANts and is written in Java back in 2004.

The ANts peer to peer file sharing program and protocol is an open source peer to peer file sharing protocol that encrypts all incoming and outgoing connections between clients in the network which makes the detection of the originating IP Address extremely difficult. The Java based peer to peer file sharing program is automatically updating and features not only point to point encrypting, but also end to end encryption as well. The software also makes multiple connection paths in order to route packets of data easier encase a node is lost. This makes the network redundant and less prone to failure and bottle neck incidents. It will automatically give preference to faster connections allowing them to be more than equal and to become part of the network’s backbone as a super node.

ANts is also capable of supporting the eDonkey links for downloading and features a built-in automatic searching capabilities. Like many other peer to peer file sharing protocols, is can support has and can fully index your files if you want t to. The network can also use a chat service; however, this chat capability is not anonymous.

All of the queries are asymmetrically encrypted so that only the original query source can view the results. Although anyone can read the query strings, the asymmetric approach means that anything another node reads, can not be interpreted by the average human mind.

In order to ensure that a node stays anonymous, all files are transferred across several nodes and the system never allows a direct download from another. All of this has been done in order to prevent another client from figuring out your client’s true location. Furthermore, ANts allows you to run a proxy such as TOR along side of the client side Java program to help further the inability to determine the originating IP address of any user.

Much effort has gone in to ensuring that not only is the network redundant in order to prevent failures, but is also completely anonymous in order to protect the various node from detection not only from their ISP, but from anyone who may be watching downloads. Unlike some peer to peer networks in existence today, their have been virtually no incidents reported in which an ANts user has had legal charges brought up against them for downloading or sharing copyrighted data.

This is not to say it is impossible, but it is not easy in the least.

Popularity: 7% [?]