Analyzing the DC File Sharing Network

This paper investigates the Direct Connect (DC) file sharing network, which to the best of our knowledge, has never been academically studied before. We developed a participating agent, in order to gather protocol specific information. We quantify network characteristics such as distribution of users in hubs, hubs geography, queries distribution and trends in shared folder size. We also characterize the typical DC user: A heavy downloader with a particularly large shared folder. Most importantly, we discovered a query duplications problem that drains much of the hubs CPU and bandwidth resources. In the DC network, query facilitation is the most demanding task for hubs and the main factor in the protocol's scalability challenges. We show that in some hubs, up to a third of the queries traffic is duplicated and therefore wasteful. Resolving this problem will dramatically improve hubs performances by reducing the amount of relayed queries and thus permitting larger hub communities.