CSTalks - Peer-to-peer - 16 Feb

  • 714 views
Uploaded on

 

More in: Technology
  • Full Name Full Name Comment goes here.
    Are you sure you want to
    Your message goes here
    Be the first to comment
    Be the first to like this
No Downloads

Views

Total Views
714
On Slideshare
0
From Embeds
0
Number of Embeds
0

Actions

Shares
Downloads
14
Comments
0
Likes
0

Embeds 0

No embeds

Report content

Flagged as inappropriate Flag as inappropriate
Flag as inappropriate

Select your reason for flagging this presentation as inappropriate.

Cancel
    No notes for slide

Transcript

  • 1. Peer-to-peer: past, present, futureCristina Cărbunaru16 February 2011
  • 2. Peer-to-peer Internet today ◦ Large number of hosts ◦ Large amount of content Significant challenges for traditional client-server architectures Make use of the inter-connectivity of the nodes in the Internet ◦ Alleviate the load from servers 2
  • 3. Client-server vs. P2p 3
  • 4. The Peer Double function: ◦ Client - consumer ◦ Server - producer Incentives to offer service, not just benefit from service More peers means more capacity added to the system 4
  • 5. P2p Goals Reduced central control Heterogeneity Flat topology Autonomy Fault resilience… 5
  • 6. History File sharing applications ◦ 1999: Napster ◦ Gnutella, Kazaa, Freenet ◦ 2001: BitTorrent (Bram Cohen) ◦ Multiple variations of p2p programs Nowadays: ◦ File sharing – among individual users or in the data centers ◦ Media streaming – on-demand or live content ◦ Communication – Skype! 6
  • 7. The beginnings: Napster 7
  • 8. BitTorrent Seed Tracker 8
  • 9. BitTorrent SeedLeecher Tracker 9
  • 10. BitTorrent 10
  • 11. BitTorrent 11
  • 12. BitTorrent 12
  • 13. BitTorrent 13
  • 14. BitTorrent 14
  • 15. BitTorrent 15
  • 16. BitTorrent Free-rider 16
  • 17. Swarm Behavior Incentive mechanisms ◦ Why offer service? Flash crowd ◦ Large number of peers choke the performance Steady state ◦ Number of peers stays constant over time ◦ Easy to predict performance Lifetime ◦ When and why is the torrent dying? ... 17
  • 18. Peer Behavior Free riding ◦ Evaluate performance loss ◦ Methods to prevent Best results with minimum of effort ◦ Cheating, but not exactly Clustering of peers ◦ Peers download/upload to similar bandwidth peers Security of content ◦ Malicious data Connectivity ◦ NAT boxes 18
  • 19. Approaches Measurement ◦ Real swarms ◦ Experimental platforms: PlanetLab, EmuLab Simulation Modeling Proposing new p2p protocols that solve different problems ◦ Proportional upload bandwidth: PropShare ◦ Amount of data transferred: Avalanche ◦ Upload bandwidth allocation among peers to get the best download speed: BitTyrant 19
  • 20. P2p in 2008/2009 (Ipoque study) 20
  • 21. Popularity Decreasing popularity for p2p file sharing ◦ Packet filtering ◦ Packet inspection ◦ Lawsuit against Pirate Bay ◦ … One click file hosting services (Rapidshare, Hotfile) become popular 21
  • 22. What to Research? Packet filtering ◦ Glasnost Hiding identity ◦ Tor ◦ Anonymous p2p Copyright issues ◦ Download might be legal in some countries ◦ Upload is illegal … 22
  • 23. What’s Next? Increasing usage of p2p protocols in other contexts: ◦ Media streaming, communication ◦ Inside the data centers ◦ Social networks ◦ Economics 23
  • 24. Future New technologies ◦ IPv6 ◦ Mobile devices From computer-to-computer to human-to-human ◦ commons-based peer production (Yochai Benkler):  Peer governance  Peer property  Peer distribution 24
  • 25. Conclusions Successful piece of research ◦ P2p transcended computer science Changed the way we share ◦ Files ◦ Knowledge ◦ Peer generated content P2p is here to stay! 25
  • 26. Questions? Thank you! 26