Embeddable Overlay Networks

Internet round-trip-times (RTTs) exhibit widespread and persistent Triangle Inequality Violations (TIVs). It has been shown that TIVs are a natural consequence of the Internet´s routing structure and they degrade the embedding accuracy of any Internet coordinate systems based on RTTs. In this paper, we simulate a coordinate system in a hypothetical overlay environment where RTTs are measured with respect to overlay forwarding that has eliminated all the TIVs. The resulting coordinate system is much more accurate and the embedding accuracy is predictable and stable (under simulated node churn) than the existing techniques based on RTTs along paths chosen by native IP forwarding. We believe that this work helps to illustrate the detrimental effects of TIVs on Internet coordinate systems, and it suggests that high quality coordinate systems in the global Internet may be possible only with overlay forwarding.