Peer-to-Peer Networks

• Minas Gjoka
• Karim El Defrawy
• Athina Markopoulou

• Xiaoyuan Yang
• Parminder Chhabra
• Pablo Rodriguez

A key challenge faced by peer-to-peer (P2P) video-on-demand (VoD) systems is their ability, or lack thereof, to provide DVD-like functionality, such as pause, forward and backward seeking (or jumps). Such operations can significantly degrade the performance of a P2P system as arbitrary video segments may need to be served timely on demand. Currently, little is known of the impact that these operations can have on the swarm efficiency, user experience and server load. In this paper, we design and implement a novel P2P system called Kangaroo, which supports DVD-like jumps. Using a carefully designed peer topology management, hybrid block scheduling algorithms, and a smart tracker, Kangaroo provides low buffering times and high swarming throughput under jump operations, without the need for overly provisioned peers or server. We experimentally evaluate the performance of the system using live VoD traces captured from a large commercial IPTV network.

• Kangaroo: Video Seeking in P2P Systems
  [ pdf, bibtex, slides ]
  Xiaoyuan Yang, Minas Gjoka, Parminder Chhabra, Athina Markopoulou, Pablo Rodriguez
  IPTPS 2009, April 2009

• Understanding the impact of VCR operations in P2P VoD systems
  [ pdf, bibtex ]
  Xiaoyuan Yang, Minas Gjoka, Athina Markopoulou,Pablo Rodriguez
  Technical Report, November 2007

The Last Frontier for P2P VOD: Your Patience at NewTeeVee.com, May 2009
1st Award at NAI 2007 (Translated from Spanish) , December 2007

BitTorrent is currently one of the most popular peer-to-peer systems. BitTorrent clients are widely spread all over the world and account for a large fraction of today's Internet traffic. In this paper, we show that BitTorrent can be exploited by misdirecting clients to send their traffic toward any host on the Internet. The volume of a BitTorrent swarm can thus be converted into firepower for launching a distributed denial-of-service attack that can exhaust the victim's resources, including access bandwidth and connection resources. We identify novel exploits of the BitTorrent system and conduct real-life experiments that demonstrate the feasibility and severity of such attacks. We characterize the volume, duration and spread of attack traffic observed in our experiments. Finally, we discuss possible fixes and the limits of both attack and defense approaches.

• BotTorrent: Misusing BitTorrent to Launch DDoS Attacks
  [ pdf, bibtex, slides ]
  Karim El Defrawy, Minas Gjoka, Athina Markopoulou
  USENIX SRUTI 2007, Santa Clara, CA, June 2007

File-sharing sites are being subverted for web attacks at New Scientist, May 2007
P2P Networks Supplement Botnets at Slashdot, May 2007