Digging into KAD users' shared folders

Pietrzyk, Marcin;Urvoy-Keller, Guillaume;Costeux, Jean-Laurent
SIGCOMM 2008, ACM annual conference of the Special Interest Group on Data Communications, August 18-22, 2008, Seattle, USA

Characterizing peer-to-peer overlays is crucial for under- standing their impact on service provider networks and as- sessing their performance. Most popular le exchange appli- cations use distributed hash tables (DHTs) as a framework for managing information. Their fully decentralized nature makes monitoring and users tracking challenging. In this work, we analyze KAD, a widely deployed DHT system. Thanks to the unique possibility to monitor a large popu- lation of about 20,000 ADSL clients at the edge of the net- work, we are able to characterize the content downloaded and shared by local users. We devised a passive content monitoring toolkit to reliably track users between sessions despite dynamic IP allocation. We applied our tool over one month of data. Our main ndings are: (i) Over half a TB of fresh data is downloaded every day by the users we monitor, (ii) A signi cant fraction of peers (20%) regulary change their ID in the KAD overlay, either on a session ba- sis or on a sub-session basis, which can be detrimental to the proper functioning of the DHT, (iii) Those users, that we term Chameleon users, are connected longer than regu- lar users, and they (claim to) have less data in their shared folder than regular peers and (iv) As a consequence, even a non biased observation of the users shared folder can only provide a lower bound of the content downloaded and shared by a population of ADSL users.


Type:
Poster / Demo
City:
Seattle
Date:
2008-08-16
Department:
Sécurité numérique
Eurecom Ref:
2542
Copyright:
© ACM, 2008. This is the author's version of the work. It is posted here by permission of ACM for your personal use. Not for redistribution. The definitive version was published in SIGCOMM 2008, ACM annual conference of the Special Interest Group on Data Communications, August 18-22, 2008, Seattle, USA

PERMALINK : https://www.eurecom.fr/publication/2542