Peer-to-Peer (or P2P) From user to user. Peer-to-peer implies that either side can initiate a session and has equal responsibility. Corey Chan Andrew Merfeld Charlie Yung

Overview for today Napster Kazaa/Limewire BitTorrent Future of P2P Networks

Napster First released June 1, 1999 3

Napster’s Features Started file sharing Easy to search FREE music Limited to MP3 downloads only

Napster’s Architecture Log on to computer. 2. Your computer connects to Napster Central Server. 3. Central Server returns complete list of songs. 4. User searches for the song. 5. Your computer connects to other users computer. 6. Downloads songs from other user computer.

Napster’s Legal Issues Music Companies sues Napster, because the artist did not get paid for songs being traded for free. Court Order shut down Napster for violating copyright infringement. Forced to shut down music sharing in July 2002. Napster ost a lot of money and users.

New Napster Paid membership Partnership with music companies to distribute music. Offer legal music

Kazaa/Limewire Released in 2000 8

Kazaa/Limewire Features Download music, video, text, pdf, possiblities endless, including viruses Most at risk with security and some clients include spyware Easy to use

Napster vs Kazaa/Limewire Centralized Quicker search/response time De-Centralized Harder to stop

How to Download a File Simply open client software, type in a search request That client searches for the file on their hard drive, and passed request onto all the computers its connected to Request gets forwarded deeper and deeper, typically 6-7 levels TTL (time to live) limits how long search request goes for

Legal Implications Unlike the Napster system, clients are direct targets RIAA (Recording Industry Association of America) has sued clients for an average of $3,000 per user MPAA (Motion Pictures Association of America) has begun to target & warn clients as well.

BitTorrent Released in 2002 13

BitTorrent History Who developed BitTorrent? When it was developed? A: Bram Cohen When it was developed? ~2002 Is it a defacto? Could say so.. Photo by Frank Ockenfels 3; Stylist/Groomer: Amanda Stansfield. Issue 13.01: The Wired magazine.

How BitTorrent is used: .torrent files located on the web Can be found through BitTorrent search engines Download process  BitTorrent program opens up .torrent file to retrieve information about download file Upload process  happens simultaneously with the download

What BitTorrent is: Protocol for transferring any type of files Peer-to-peer networking Centralized server  Full Mesh topology Tracker file used to define information being sent  “the packets” in a network

BitTorrent Network Structure shown with centralized server directing tracking information to computers in P2P network. From “NTL And BitTorrent Announce P2P File-Sharing Trial” Feb 13 2006

BitTorrent vs. Kazaa BitTorrent allows users to connect to each other through a torrent source file for maximum bandwidth allowances Has the ability to upload impartial pieces of the targeted file for download Kazaa connects through many users but doesn’t take advantage of BitTorrent’s download/upload efficiency technology Files must be complete for uploading

BitTorrent Contrast Advantages: Disadvantages Faster speeds (compared to Kazaa) Connection efficiency Reliable Many search engines to find files Disadvantages Difficulty level of starting a torrent to share Hurts music, movie industry More complicated process to download files

Future for P2P Networks Darknets – private peer to peer networks “Underground” compared to open networks Invitation only by the operators Mostly programmers start Darknets “A darknet as a group of individuals who have a covert, dispersed communication channel.” ~Eric Cole of Lockheed Martin, advanced technology company

Questions? Thank you for your time.