Abstract:The available bandwidth (ABW) of a network path is a crucial metric for various applications, such as traffic engineering, congestion control, multimedia streaming, and path selection in software-defined wide-area networks (SDWAN). In recent years, a new class of measurement methods have been proposed to estimate the available bandwidth, decreasing-chirp-train methods. However, the performance and limitations of this new class of methods are neither well studied nor fairly compared beyond simulation studies. In this work, we implement Voyager, a modular framework that allows us to conduct a fair and thorough comparison of how a variety of modern bandwidth estimation methods perform under different network paths and traffic conditions. We shed light on the characteristics and limitations of the internal algorithms of various methods, and propose two new methods. We investigate the impact of various bottleneck types and traffic types, and we explore the performance of these methods on high speed links where interrupt coalescence can cause measurement noise. We finally test Voyager on long-distance Internet links and with live traffic and report our findings.

Key Words: Computer network, Internet, protocols, bandwidth estimation, active probing, network measurement tools, probing rate model, bottleneck, end-to-end path.