According to a survey by Sandvine, a vendor of bandwidth-management systems, the three biggest overall generators of Internet traffic in May were: peer-to-peer file sharing (43.5%), Web browsing (27.3%), and streaming media (14.8%). Other applications, ranked by overall usage, were: tunneling into private networks (5.9%), newsgroups (5.6%), online games (1.4%), and voice over IP (0.2%). P2P accounted for an even bigger portion of upstream direction, consuming more than twice as much traffic as all other traffic combined. The three biggest traffic generators in the upstream direction are peer-to-peer file sharing (75.0%), tunneling (9.9%), and Web browsing (9.1%). Downstream traffic was also primarily generated by P2P (35.6%), followed by Web browsing (31.6%) and streaming (17.9%). Sandvine plans to make the report available on its Web site (http://www.sandvine.com/) Wednesday.