Magellan
Live peer-to-peer (P2P) multimedia streaming applications have been successfully and commercially deployed in the Internet with up to millions of users at any given time. As a commonly adopted design for most of the recent successful P2P live streaming applications, blocks of live media contents are being delivered over a mesh overlay topology, featuring a BitTorrent-like reciprocal exchanges of useful content blocks among multiple peers. It is also interesting to observe that most current-generation P2P streaming applications employ relatively simple peer selection and mesh construction protocol designs. They typically use central tracking servers to gain initial knowledge of existing peers in the channels, and periodically exchange peer lists among peers themselves.
As mesh-based streaming topologies play an important role towards the commercial success of P2P streaming, it is critical to acquire a thorough and in-depth understanding of the topological characteristics of these large-scale P2P meshes. It would be an intriguing research challenge to investigate how the constructed topologies actually behave in practice, dynamically evolve over time, and react to extreme scenarios such as huge flash crowds.
Within the academic community, there has been an increasing level of attention on measurement studies with these real-world streaming applications. An increasing number of measurement studies has treated commercial applications as “blackboxes,” and explore their behavior using traffic monitoring tools. The bad news is, there are only so much one can do with a measurement-based study treating the application in question as a “blackbox.” If we wish to gain in-depth insights and a complete understanding of P2P streaming characteristics, we need to collaborate with commercial solution providers and add instrumentation facilities into the product itself! With the Magellan project, we wish to achieve exactly that, by collaborating with UUSee Inc., one of the leading P2P live streaming solution providers in mainland China, supported by reputable venture capital firms in North America.
— Charting large-scale peer-to-peer live streaming topologies: Our ICDCS 2007 paper represents the first milestone of Magellan, with our observations from exploring graph theoretical properties in actually formed live streaming topologies. All of our observations are based on over 120 GB of traces and 10 million unique IP addresses that we have collected over a two-month period (September to October 2006) using dedicated trace servers, and instrumented client code to proactively submit reports to trace servers.
— Characterizing peer-to-peer streaming flows: Our IEEE Journal on Selected Areas in Communications paper represents the second milestone of Magellan. Again, we have taken the time to conduct an exhaustive investigation with respect to statistical properties of the TCP throughputs of streaming flows among peers, using more than 230 GB of UUSee traces and 370 million live streaming flows over a four-month period of time (November 2006 to February 2007). In particular, we have investigated TCP throughput distributions in various peer ISP/area/type categories, statistically tested the correlation between TCP throughput and its application-layer factors by modeling them into regression models, and studied the evolutionary properties of TCP throughput values over the trace period.