Figure 6: The average download speed of peers. of downloads for a single file as a function of time
(the Lord of the Rings III movie with size 1.87 GByte).We have selected this file because it uses a tracker (FutureZone.TV) which provides access to detailed statistics ,which we collected every five minutes with our Tracker script. The top line shows the sum of the number of downloads in progress and the number of seeds accordingto this tracker, while the bottom line only shows the number of seeds. During the first five days, no peer finished downloading the file and the injector of the file was continuously online. This long time period provides a clear Opportunity to identify copyright violators. The statistics from Supernova were fetched by our HTML script every hour, and are in agreement with the total tracker resultsto such an extent that the lines overlap almost completely.Only on December 23, 2003 there was a problem with the tracker for a few minutes, which is not visible intheSuprnova data. The results from the Peerping script
show a significantly lower number of downloads, which is due to the firewall problem (40 % of the peers were (fire walled). The gaps in the Peer ping results were due to disk quota problems on the DAS, which ran our measurementsoftware. From the measurements we conclude that the global BitTorrent/Suprnova components are capable of efficiently handling very large flashcrowds. Also, because of the strong sudden increase in the number of downloaders, it is clear that the arrival process is not Poisson.