Highways: Proximity Clustering for Scalable Peer-to-Peer Network

The "location-aware" construction of overlay networks requires the identification of nodes that are efficient with respect to network delay and available bandwidth. In this short paper, we propose Highways to create clusters of nodes using a novel "location-aware" method, based on a scalable and distributed network coordinate system. This helps to build overlay routing tables to achieve better proximity accuracy, thus, providing a mechanism to boost performance in application overlay routing

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

On the accuracy of embeddings for Internet coordinate systems

Internet coordinate systems embed Round-Trip-Times (RTTs) between Internet nodes into some geometric space so that unmeasured RTTs can be estimated using distance computation in that space. If accurate, such techniques would allow us to predict Internet RTTs without extensive measurements. The published techniques appear to work very well when accuracy is measured using metrics such as absolute relative error. Our main observation is that absolute relative error tells us very little about the quality of an embedding as experienced by a user. We define several new accuracy metrics that attempt to quantify various aspects of user-oriented quality. Evaluation of current Internet coordinate systems using our new metrics indicates that their quality is not as high as that suggested by the use of absolute relative error.