We have demonstrated that network coordinates in the wild do behave
somewhat differently than do tame coordinates on PlanetLab or in
Fortunately, even these wild coordinates can be tamed.
Our analysis of a large, Internet-scale coordinate system has
convinced us to join the network coordinate supporters camp. While
the initial network coordinate implementation illustrated some of the
problems that critics often cite, we found that simple, but effective
techniques overcame nearly all these issues. In Azureus, network
coordinates provide a simple and efficient mechanism for anycast, as
part of DHT lookups, and may soon be used to optimize streaming media.
In addition to providing a wealth of data and analysis from a live,
large-scale deployment, we have deployed and evaluated six techniques
that improve the accuracy and/or stability of network coordinate
systems: latency filters, update filters, neighbor decay, coordinate
memory, gravity, and violator exclusion.
Together, these yield efficient, accurate, and stable network
coordinates in the million-node Azureus network.
In the future, we plan to add the remaining techniques to the Azureus
code and monitor their effectiveness.