3 Latencies in the Wild


3 Latencies in the Wild

Before we examine the accuracy with which Internet-scale latencies can be embedded into a coordinate space, we compare latencies in Azureus to those in other networks to gain insight into the causes of error in Internet-scale embeddings. We generate a dense latency matrix of a subset of Azureus and compare it to PlanetLab and to the MIT King data set, a square matrix containing the median latencies between 1740 DNS servers collected using the King method [9,14]. Researchers found PlanetLab and MIT King can be reduced to low dimensional coordinates with less than or equal to 10 percent median error [18,9]. We examine three characteristics: inter-node round trip times, violations of the triangle inequality, and the intrinsic dimensionality of the data sets.

Subsections

Jonathan Ledlie 2007-02-23