Explication et réduction de l'impact des violations d'inégalités triangulaires dans Vivaldi

Network coordinate systems embed delay measurements (e.g. RTT) between Internet nodes into some metric space. These systems often assume the triangle inequality holds for Internet delays. However, the reality is that the triangle inequality is violated by Internet delays. In a first step, we explore the ways in which TIVs impact the Vivaldi coordinate system using different metrics in order to quantify various levels of TIV's severity. In a second step, we study TIVs existing in the Internet. Our results show that path lengths do have an effect on the impact of these TIVs. In particular, we observed correlation between the (in)stability and high effective error of nodes' coordinates with respect to their involvement in TIVs situations. Finally, we propose a Two-Tier architecture that does mitigate the effect of TIVs on the distance predictions.