How P2P networks work - 'Kazaa' analysed
... be no exchanging of data, and the system (FastTrak) would become obsolete. The heart, if you will, of P2P is actually being “connected”, to each other, and for this to work a connection to the internet is required. Without an established connection to one another, the FastTrak network would surely fail. The FastTrak network, as all P2P networks, isn’t restricted, in the geographical sense. Therefore it could be said that this particular system can be used anywhere and everywhere, provided that the other information systems required to make the FastTrak system work, is adequately available in that particular area. Of course, there are simply some places where it can’t be used, such as third-world countries, which do not have adequate internet access, and the polar regions, for the same reason. To extend on this, the FastTrak P2P network would be used in more urbanized and civilized locations, where technology has evolved. The US has the strongest users / participants of the FastTrak network, as cable internet (fast download and upload transfer rates) is relatively cheap compared to some other regions (New Zealand, Asia-Pacific). The Role of Participants and Users: In any P2P network, users and participants are required to make the system work. Without them, the system would fail, for obvious reasons which already have been discussed. In the Kazaa (FastTrak) P2P network, there are two main “groups” of people: the users, or peers, which are the exchangers of data (upstream and downstream wise), and the “super-peers,” who have a much more significant role. “Super-peers” act as local search hubs, as they index files belonging to other nodes. When normal users (peers) pose a query for a particular song title, for example, these “super-peers” parse through their indexes, probing individual nodes for the specified keywords. If the nodes return a successful match, these are returned to the peer by the super-peer. In Kazaa, the peer is shown a list of successful returns, whereby the the user/peer has the option to begin downloading immediately. Of course, whilst this process costs nothing for the peer, the incentive to become a super-peer is decreased as becoming a super-peer generally means higher bandwidth usage and higher processing power is required, and as a direct correlation means higher costs. It could be said that a tension exists. The more “neighbours” or nodes (that is, normal users – peers) a super-peer indexes, the higher the efficiency of search performance, but also the higher the communication costs, and since a normal node (peer – user) can simply connect to another super-peer rather than becoming one itself, the incentive to become one lowers. To summarize, there are two (2) main groups of users in the Kazaa (FastTrak) P2P network. The peers, or the users who simply “do” the transferring, that is, they upload and download data, and the super-peers, who act as local search hubs. They index the files of other users, or nodes, and provide you, the user, with the search results you initiate. Super-peers are, simply put, normal peers who, according to their available bandwidth, processing power, etc, are given the role of super-peer. Please refer to the table below: Peers Super-Peers Advantages • Need not worry about reduced bandwidth and other reduced performance issues which come with being a Super-Peer. • Have the same performance as being a peer than being a super-peer • Less chance of being “caught-out” by the RIAA. • Provide faster and efficient search results for peers. • Have priority in download queues (Unless Kazaa Lite is used, whereby this mechanism is bypassed.) • Help the P2P community thrive. Disadvantages • Have low(er) priority in download queues. • Not helping the P2P community grow – “if you’re not part of the solution, you’re part of the problem” • Higher chance of being “caught-out” by organizations such as the RIAA. • Heavy bandwidth usage and processor usage – leads to higher costs. • No performance gain, rewards, etc, provided for becoming a super-peer – low incentive. Data involved in the System: Since this is a P2P network, the data which is put into the system plays a heavy role. Users of the software have the choice to: Make available their files Not make available their files (disable uploading) Only privately make available their files As mentioned before, whilst *.mp3 files (compressed sound files using the mp3 codec [compression-decompression]) are the most popular types of data being transferred in the FastTrak P2P network, the user is not restricted to only this type of file. Users, or peers, are able to share any files of any extension, be it *.zip, *.rar, *.exe, *.pdf, *.iso, and so forth. File Extension Explanation *.exe Executable files. Since all users of Kazaa are using a 32-bit operating system, we can safely assume these are PE (portable executable) files. *.exe files can range from self-extractors, programs, games, etc, to more malicious objects such as virii, worms, etc. *.mp3 The most popular type of file being distributed on P2P networks. This is a compressed sound (music) file using the MPEG-Layer 3 codec for decompression routines. *.zip Popular type of compressed archive available. Can archive many files, but can only have a size of 2 gigabytes. *.rar Another popular type of compression available. Offers significantly better compression ratio than *.zip. Also has many useful features such as integrity checking, recovery record, and archive locking. *.pdf Used by Adobe Acrobat and other *.pdf readers. “E-books” are usually *.pdf files. *.iso ISO files are images of CD’s. They are popular because they offer a means to distribute an entire piece of software without having to “rip” features out. Usually compressed in a multi-part archive (*.rar) for easy management and transfer. Of course, these aren’t the only types of files which users are able to input into the system, however these are the more popular types. Of course, this only covers the things the user directly has control over. As in any P2P environment, there are some things which the user has no control over. I am of course talking about private information which you wouldn’t want to become public knowledge. Consider this scenario. Bob privately shares his files, which are comprised of various music files, software, etc. Now, since Bob has private sharing enabled, he’s files aren’t indexed by the super-peers, and therefore users wishing to access Bob’s files must know his exact username, and search for that. Now, say Bob only wants Mark access to his files, but somehow John gets a hold of Bob’s username. John has access to all of Bob’s files, even though Bob only wants Mark to have access to his files. It could be said that John was able to gain sensitive information from the system. Also consider this scenario. Bob makes all his files in his “My Shared Files” folder available to everyone. But Bob accidentally places sensitive information, say, a text file containing his credit card details, in his “My Shared Files” directory. Everyone is now able to access this sensitive piece of information. Whilst these scenarios are hypothetical and unlikely to occur, it is important to be aware of that all your “shared” files are available to public access. Also, it should be mentioned that your IP address, (for cable users, this is static, that is, you are assigned a unique number by your ISP, number consisting of four (4) subnets, ranging from 0x00h – 0xFFh (0 – 255)) is made available upon transfer of a file. A user may simply perform a “netstat –n –o” (the –n switch displays IP in numerical form and the –o switch displays the PID associated with the address, thereby making it easier to confirm which address is associated with Kazaa (each process having a unique handle)) command in the console prompt. To summarize, the data the user inputs into the system is made publicly made available. Also, like any information system, sensitive information can be obtained if one is not too careful. The Information Technology used by the System: The FastTrak network, like all P2P networks, utilizes information technology in order to maintain and run. Information Technology refers to the hardware and software used by the information system. For Kazaa to work, obviously the participants will need a copy of the Kazaa software, available as freeware on many sites such as www.download.com, www.tucows.com, and www.kazaa.com. Although irrelevant, people will, of course, require a computer, which can be built “from scratch” (purchasing individual peripherals and hardware) or bought as a package deal. The P2P information system relies on an internet connection, so a modem is required. This includes, but is not limited to, a 28.8kb modem, 56.6kb modem, ISDN, ADSL bridged modem, ADSL modem/router, Cable modem/router, or a T1/T2/T3 line. For an ADSL modem/router to operate correctly, additional microfilters are required to filter out noise from the telephone line. In order a successful internet connection to be established, the Point-to-Point Protocol (for dial-up, Dial-Up Networking must be available and installed) must be available on the machine. The Point-to-Point Protocol over Ethernet (PPPoE) is often used by ADSL providers, as it provides access control and billing functionality in a manner similar to dial-up services using PPP. Point-to-Point Protocol over ATM Adaptation ...