ITIS 1210ITIS 1210Introduction to Web-Based Introduction to Web-Based

Information SystemsInformation Systems

Chapter 38Chapter 38

How Music Sharing and File Sharing WorkHow Music Sharing and File Sharing Work

IntroductionIntroduction

Internet is not Internet is not justjust another data delivery another data delivery mechanismmechanism Potential to change society in profound waysPotential to change society in profound ways

Other examples?Other examples? Printing pressPrinting press Tape recordersTape recorders PhotocopiersPhotocopiers VCRVCR

IntroductionIntroduction

Music-sharingMusic-sharing Changed the way people used the InternetChanged the way people used the Internet Threatened traditional music industryThreatened traditional music industry

How?How? Let people share their own music with othersLet people share their own music with others Make a copy of your CDMake a copy of your CD Post your copy where others can access itPost your copy where others can access it

And copy it to And copy it to theirtheir PCs PCs

Copy files others have posted to Copy files others have posted to youryour PC PC

IntroductionIntroduction

NapsterNapster

Music industry’s reaction?Music industry’s reaction? LawsuitLawsuit Copyright violationCopyright violation

First major company sued was NapsterFirst major company sued was Napster

NapsterNapster

NapsterNapster

Shaun FanningShaun Fanning Student at Northeastern U.Student at Northeastern U. Beta version given to 30 Beta version given to 30

friends on June 1, 1999friends on June 1, 1999 Within a few days 10,000 to Within a few days 10,000 to

15,000 people had 15,000 people had downloaded itdownloaded it

Used central serversUsed central servers

NapsterNapster

NapsterNapster

Metallica discovered ”I Disappear” was Metallica discovered ”I Disappear” was circulating before its releasecirculating before its release Filed suit in 2000Filed suit in 2000

Dr Dre requested his works Dr Dre requested his works be removedbe removed Filed suit when Napster Filed suit when Napster

declineddeclined

NapsterNapster

Music industry sued in December 1999Music industry sued in December 1999 Napster lost but appealedNapster lost but appealed

Only facilitators, not their fault users were using Only facilitators, not their fault users were using their service illegallytheir service illegally

Ninth Circuit Court issued injunction in Ninth Circuit Court issued injunction in March 2001March 2001 Napster shut down in July 2001Napster shut down in July 2001

Paid $26,000,000 settlementPaid $26,000,000 settlement Bankruptcy followed in September 2002Bankruptcy followed in September 2002

NapsterNapster

Roxio acquired assetsRoxio acquired assets Launched Napster 2.0Launched Napster 2.0

Paved the way forPaved the way for iTunesiTunes GroksterGrokster GnutellaGnutella KazaaKazaa

Peer-to-Peer NetworkPeer-to-Peer Network

Does not use a central serverDoes not use a central server Individual users communicate separatelyIndividual users communicate separately

Share software, movies, sound files, etc.Share software, movies, sound files, etc. Business peer-to-peer now popularBusiness peer-to-peer now popular

www.groove.netwww.groove.net Enables workers to create private workspace Enables workers to create private workspace

to share files, messages, softwareto share files, messages, software Irony: guerilla movement embraced by Irony: guerilla movement embraced by

corporate Americacorporate America

KazaaKazaa

Download Kazaa and install it on your PCDownload Kazaa and install it on your PC www.kazaa.comwww.kazaa.com

Software connects to a Kazaa serverSoftware connects to a Kazaa server Your PC receives a list of Your PC receives a list of supernodessupernodes

Localized search sites for the file-sharing networkLocalized search sites for the file-sharing network Ordinary PCs withOrdinary PCs with

High-speed Internet connectionsHigh-speed Internet connections Powerful processorsPowerful processors

Your PC could become a supernodeYour PC could become a supernode

KazaaKazaa

Your PC contacts a nearby supernodeYour PC contacts a nearby supernode Sends to it information about all the music Sends to it information about all the music

files on your computerfiles on your computer Name of recordingName of recording Your IP addressYour IP address Your Kazaa IDYour Kazaa ID

Supernode stores this information it its Supernode stores this information it its databasedatabase

KazaaKazaa

When you search for music you supplyWhen you search for music you supply Name of artistName of artist Song titleSong title

Kazaa contacts nearest supernodeKazaa contacts nearest supernode Which may contact other supernodesWhich may contact other supernodes

Builds a list of matching titles and Builds a list of matching titles and computers they’re stored oncomputers they’re stored on

KazaaKazaa

You choose which one you wantYou choose which one you want Software downloads it directly from Software downloads it directly from

computer you pickedcomputer you picked Not from supernodeNot from supernode

BitTorrentBitTorrent

Another technology for file sharingAnother technology for file sharing Not just audio filesNot just audio files Videos, spreadsheets, etc.Videos, spreadsheets, etc. Entire CDsEntire CDs

Also enables corporations to efficiently Also enables corporations to efficiently distribute software to multiple locationsdistribute software to multiple locations Latest version of company applications that Latest version of company applications that

need to be distributed to many offices at once need to be distributed to many offices at once (i.e., a new release)(i.e., a new release)

BitTorrentBitTorrent

Operates somewhat differentlyOperates somewhat differently Downloads parts of final contentDownloads parts of final content From multiple sitesFrom multiple sites Assembled at destinationAssembled at destination

Starts by downloading and installing client Starts by downloading and installing client softwaresoftware Freely available from www.bittorrent.comFreely available from www.bittorrent.com

BitTorrentBitTorrent

Users visits a site specializing in Users visits a site specializing in BitTorrent downloadsBitTorrent downloads

Site downloads a Site downloads a torrenttorrent file file ““Pointer” file containing information and Pointer” file containing information and

instructionsinstructions Where and how a file can be downloadedWhere and how a file can be downloaded Included is address of a Included is address of a tracker servertracker server Also filename, size, checksum of every block Also filename, size, checksum of every block

to be downloadedto be downloaded

BitTorrentBitTorrent

BitTorrent client talks to tracker server that BitTorrent client talks to tracker server that providesprovides Address information of all computers that Address information of all computers that

have the requested file or portions thereofhave the requested file or portions thereof These are These are seed computersseed computers Every seed computer with all or part of the file Every seed computer with all or part of the file

is called a is called a swarmswarm

Downloading from seed computers Downloading from seed computers happens simultaneouslyhappens simultaneously

BitTorrentBitTorrent

Speeds up the overall process significantlySpeeds up the overall process significantly Once assembled the complete file is used Once assembled the complete file is used

as normalas normal Downloading can happen at the same time Downloading can happen at the same time

as uploadingas uploading The Client can be working in both directions The Client can be working in both directions

to assist other BitTorrent usersto assist other BitTorrent users

BitTorrentBitTorrent

BitTorrent controls client privilegesBitTorrent controls client privileges Clients that leave BitTorrent runningClients that leave BitTorrent running

And thus upload to other computers moreAnd thus upload to other computers more Will be given privileges to download fasterWill be given privileges to download faster Than computers that rarely uploadThan computers that rarely upload