A Retrospective Approach for Accurate Network Latency Prediction

Network coordinate systems can efficiently predict the round-trip time between any pair of nodes on the Internet. These systems map nodes onto a multi-dimensional coordinate space such that the round-trip time between two arbitrary nodes can be estimated by the distance between the corresponding pair of points in the coordinate space. In these systems, each node continuously updates its coordinates based on the latencies of new communications and the coordinates of other nodes. Node coordinates obtained in this manner, however, may be misled by erroneous information, such as extraordinary roundtrip times. Previous techniques attempt to overcome this problem by having nodes reject new information if it is inconsistent with the current coordinates. These techniques are still inappropriate if the coordinates are not sufficiently accurate. In this paper, we develop a new approach where each node preserves recent communication history. To update a node´s coordinates more accurately, our approach re-evaluates the records in the node´s history while ignoring inconsistent communication records and applying a higher weight to more reliable records. This approach thus can prevent node coordinates from being affected by erroneous information that was difficult to detect in the past. Through evaluations based on real network trace data, we demonstrate that our approach can reduce network latency prediction errors by 50% compared to previous approaches.