Real-Time Measurement of End-to-End Available Bandwidth: A Feasibility Study

We propose a real-time measurement method, DPDC (Detection of Packet-Delay Correlation), which models both available bandwidth and the averaging time scale. In this method, measurement periods are short and constant, while the theoretical measurement error is reduced. DPDC is established based on the discussion of the systematic error of the packet pair/train measurement. We evaluate through simulations its accuracy and robustness against the multihop effect. We also verify the feasibility of real-time measurements through testbed experiments using a tool called Linear that implements DPDC. Efficiency is demonstrated through simulations and testbed experiments by analyzing accidental and systematic errors. Finally, we discuss the available bandwidth variation in an Internet path using real-time data produced by Linear measurements and passive monitoring.