Bellissimo et al. [19] collected statistics from two trackers
to conduct their measurement-based evaluation. The statistics
included the user’s random ID, how long the user had been
connected to the torrent, and the number of bytes uploaded,
downloaded, and remaining. Their results showed that (1)
BitTorrent can serve large files effectively; (2) the incentive
mechanisms are effective.
In [23], Skevik et al. focused on the effect of the firewalls
and the time the peers have stayed in the system. They
monitored the torrents of RedHat and Mandrake Linux for
several months by executing a modified client and a crawler.
They observed that peers behind a firewall have low bandwidth
usage and they are more likely to leave the system early
because of their poor download performance.