Performance Improvement of a Distributed Internet Coordinates System

Abstract

The increasing popularity of Internet wide overlay networks require mechanisms for delay prediction between any given pair of nodes without having to actually measure the delay. Internet Coordinate Systems (ICS) have been proposed to enable such delay prediction. Most of the known ICS mechanisms require a set of landmark servers for hosts to measure their distance with and use those mea- surements to derive their coordinates. For P2P systems, it is preferable to use a distributed scheme where deployment of landmarks are not required. Vivaldi is such a distributed scheme. We propose an improved scheme in which hosts dynamically change the set of neighbors with which they measure distances. Our proposed improvement to the Vi- valdi algorithm reduces the bandwidth consumption by up to 50% while maitaining the same accuracy of the delay es- timations. We introduce a new metric named relative delay loss (rdl) that captures how well the coordinate system picks the closest node between two given nodes and captures the magnitude of the error when the pick is wrong. Our pro- posed scheme presents a significant improvement measured with this new metric.