徐晨桓 李柏穎

 Definition  Introduction  History  Example - Napster  Example - Gnutella 徐晨桓 李柏穎 2/27

 File system + File sharing + Multi-user  Synchronization in OS (Single user)  multi-user operating system  Network File System (NFS) 徐晨桓 李柏穎 3/27

 File owner/creator  Types of access Read 、 Write 、 Execute 、 Append 、 Delete 、 List 徐晨桓 李柏穎 4/27

 An active file is open to one or more run units.  An inactive file is one that is not open to any run unit.  Active files can be open in one of two modes: exclusive or shareable:  Exclusive open to one run unit only  Shareable available to any number of run units 徐晨桓 李柏穎 5/27

Peer-to-Peer (P2P) File Sharing  most popular, but controversial  Network computer users locate shared data.  collecting and segmenting large files into smaller pieces. File Hosting Services  alternative provides a broad selection of popular online material.  These service websites usually host files to enable users to download them. 徐晨桓 李柏穎 6/27

 Files were first exchanged on removable media.  bulletin board systems (1978), Usenet (1979), and FTP servers (1985). Internet Relay Chat (1988) and Hotline (1997) enabled users to communicate remotely through chat and to exchange files. 徐晨桓 李柏穎 7/27

 In June 1999, Napster was released as an unstructured centralized peer-to-peer system.  Gnutella was the first decentralized file sharing network. no central point of failure  Freenet was released and became the first anonymity network. 徐晨桓 李柏穎 8/27

徐晨桓 李柏穎 9/27

 Definition  Introduction  History  Example - Napster  Example - Gnutella 徐晨桓 李柏穎 10/27

 Release in 1999  pioneering p2p file sharing Internet service  MP3 file sharing  John Fanning, Shawn Fanning and Sean Parker 徐晨桓 李柏穎 11/27

Hybrid P2P 徐晨桓 李柏穎 12/27

 Redefine the music industry and the way we all think about intellectual property.  1000s of copies of copyrighted songs  Shutdown in 2001  Restart in 2003 as non-free service  Currently become online music store 徐晨桓 李柏穎 13/27

Hybrid P2P 徐晨桓 李柏穎 14/27

 Definition  Introduction  History  Example - Napster  Example - Gnutella 徐晨桓 李柏穎 15/27

Gnutella decentralized P2P File Sharing Network G

 First Decentralized p2p network, pure P2P  Released in 2000, open source  Developed by Justin Frankel & Tom Pepper  Released on web of American Online 徐晨桓 李柏穎 17/27

 Ping  Pong  7 Hops  Query  Hit 徐晨桓 李柏穎 18/27

Ultrapeers Leaf ask file A 徐晨桓 李柏穎 19/27

Ultrapeers Leaf QRP ask file A Query Routing Protocol Saving 70% traffic 徐晨桓 李柏穎 20/27

Ultrapeers Leaf QRP DR ask file A Dynamic Routing 徐晨桓 李柏穎 21/27

Ultrapeers Leaf QRP DR ask file A Dynamic Routing 徐晨桓 李柏穎 22/27

Ultrapeers Leaf QRP DR Finding sources without searching ask file A 徐晨桓 李柏穎 23/27

Ultrapeers Leaf QRP DR Finding sources without searching Swarming and Partial File Sharing 徐晨桓 李柏穎 24/27

leaf Ultra peer leaf Ultrapeers Leaf QRP DR Finding sources without searching Swarming and Partial File Sharing Firewall 徐晨桓 李柏穎 25/27

 Was taken down the next day after releasing  This did not stop Gnutella  Open source clones started showing up 徐晨桓 李柏穎 26/27

  =%2Fcom.microfocus.eclipse.infocenter.enterprisedevelop er.eclipsewin%2FHRLHLHPDF61F.html =%2Fcom.microfocus.eclipse.infocenter.enterprisedevelop er.eclipsewin%2FHRLHLHPDF61F.html      徐晨桓 李柏穎 27/27

徐晨桓 李柏穎