Streaming MAGNeT

In order to determine what visible effect the operation of MAGNeT has on streaming media we set up a web server on one of our test machines to stream an 8-minute, 51-second MPEG clip of Crocodile Dundee. We then viewed the clip with MAGNeT running only on the server, with MAGNeT executing only on the client, and with MAGNeT not installed at all.

Our results are summarized in Figure 7. Note that most streaming MPEG clients buffer data to maintain a constant framerate. This fact implies that frames-per-second is a misleading measure of streaming network performance. Therefore, the metric we have chosen is the total wall-clock time taken for the entire clip to be sent to the client.

As can be seen, MAGNeT has minimal effect on MPEG streaming. Over 100 trials, the average time to stream the movie clip without MAGNeT is 46.02 seconds, with a 95% confidence interval of $\pm$0.07 seconds. To transfer the movie clip with MAGNeT running on the server took an average 46.07 seconds, and with MAGNeT on the client, 46.05 seconds. (Both of the MAGNeT cases have a 95% confidence interval of $\pm$0.06 seconds.) As a point of comparison, tcpdump increases the streaming time to approximately 52 seconds.

Figure 7: Streaming MAGNeT Effects