Characterizing the Configuration of Starlink Queuing

2026-05-26

AI Summary

This study addresses the opacity of Starlink’s queue management mechanism, which has hindered a thorough understanding of its network performance and congestion control behavior. By employing high-precision, controlled burst traffic generation combined with one-way delay measurements, packet loss analysis, and queue simulations, this work provides the first evidence that Starlink employs a drop-front buffering strategy rather than conventional per-flow fair queuing or drop-tail mechanisms. While this approach effectively reduces queuing delay, it may adversely impact loss-based congestion control algorithms, potentially leading to reduced throughput. These findings offer critical insights for optimizing transport protocols in satellite internet environments.

Abstract

In all networking systems, queuing is important to ensure appropriate resource utilization in the presence of bursty traffic and varying traffic demands. The Starlink access network is additionally also dynamic in terms of the capacity it can provide, and thus queuing plays an even greater role to ensure appropriate communication performance for the end-users while maintaining high resource utilization. However, for Starlink most system design details, along with the setup of the internal queuing, is private information and not publicly available. To address this we have developed a high-precision, burst-pattern controlled, traffic generation approach allowing us to precisely measure the one-way delay for Starlink. By analyzing the delay and loss in conjunction with a queue simulator we find that Starlink does not employ per-flow fair queuing or drop-tail buffers, but it does use drop-front buffer management. While drop-front reduces delay, it may also interfere with the assumptions made by loss-based congestion controls, potentially contributing to throughput degradation.

Problem

• Starlink
• queuing
• network performance
• buffer management
• delay characterization

Innovation

• Starlink
• queuing mechanism
• drop-front buffering
• traffic generation
• congestion control