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Peer-2-Peer Computing – The Problem with KaZaA Peer-2-Peer computing is a relatively recent phenomena that distributes information among the peer nodes instead of concentrating it at a central location (at least in its purest form).
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Peer-2-Peer Computing – The Problem with KaZaA Peer-2-Peer computing is a relatively recent phenomena that distributes information among the peer nodes instead of concentrating it at a central location (at least in its purest form). The allows the broad sharing of information among peers. P-2-P has been widely used to share music files. There are multiple P-2-P Models from centralized (Napster) to fully distributed (Gnutella). KaZaA is an intermediate model and recent example of P-2-P and was developed in Amsterdam by Fast track, Inc. Others include: Gnutella, Morpheus, Win MX, BearShare, Edonkey2000, Direct Connect, Audio Galaxy, and many, many more. KaZaA
KaZaA – How it works Has a centralized server that maintains user registrations, logs users into the systems to keep statistics, provides downloads of client software, and bootstraps the peer discovery process. Requires a client to be installed on your computer. Two client types are supported: Supernodes (fast cpus + high bandwidth connections) Nodes (slower cpus and/or connections) Supernodes addresses are provided in the initial download. They also maintain searchable indexes and proxies search requests for users. KaZaA
KaZaA – Client Software A graphical user Interface (GUI) – somewhat like Microsoft Outlook. Supports an instant messaging feature (P-2-P, not community chat) A database of supernodes and/or peers. A search engine to identify the location of desired files by name and keyword (keyword descriptors are generated and stored in file descriptors for each file). A rudimentary web (file) server that delivers files to peers on request. Security: – User downloads a client – no control over functionality - client exposes files shares to the external world KaZaA
KaZaA – Graphically Search Request (Title, Keyword) Central Server Supernode Initial Registration Initial Download Search Response (peer IP, File 3) User Peer 1 Peer n Get File 3 File 1 File 2 File 3 . File n File 1 File 2 File 3 . File n File 1 File 2 File 3 . File n KaZaA
KaZaA – Some Details On initial registration, the client may be provided with a list of more than one supernode. Supernodes are “elected” by the central server – users can decline. Supernodes can come and go so links may fail over time. If a peer attempts a connection and fails, it can request the supernode to refer the request – becomes important when a firewall is used. File transfers use http protocol and port 1214 (the KaZaA port). KaZaA
KaZaA – The Firewall Breach – Part 1 Protected Network Internet Insider initiates: SYN, SYN ACK, ACK, Search + Response: Outbound any is OK 1 A B 2 Insider initiates: SYN, SYN ACK, ACK, Get File: Outbound any is OK KaZaA
KaZaA – The Firewall Breach – Part 2 Protected Network Internet No activity, but connection is always ON Outsider initiates: SYN, SYN ACK, ACK, Search + Response: Response Ids system behind the firewall 1 2 Outsider initiates: SYN: Firewall drops Inbound not OK for this service KaZaA
KaZaA – The Firewall Breach – Part 3 Protected Network Internet SYN, SYN ACK, ACK, Message: Connect to B 2 A Outsider initiates: SYN, SYN ACK, ACK, Message: Tell A to Connect to B 1 3 Insider initiates: SYN, SYN ACK, ACK, Message: Several, but result is the file is transferred. Tricky way to get past a firewall. B KaZaA
KaZaA – Consequences Huge bandwidth Hog – U of Vermont (45% of Internet bandwidth) Potential for original client download to be a Trojan – it is. Potential for files downloaded into the protected network to be Trojans. On the other side: P-2-P is coming and many think is the next internet KILLER APP. Where web centralizes information access, P-2-P distributes. Next generations will have security controls. KaZaA
KaZaA – The Trojan KaZaA clients come complete with a Trojan from Brilliant Digital Entertainment. 3D advertising technology + node software that can be controlled by Brilliant Digital. Intent is to use the massed horsepower to host and distribute content belonging to other companies for a fee. With the user’s permission of course – opt out basis (not opt in!). Content to include advertising, music, video – anything digital. Also have mentioned tapping unused cycles to do compute work. KaZaA