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arXiv · 2603.04381

A DualPI2 Module for Mahimahi: Behavioral Characterization and Cross-Platform Analysis

Nawel Alioua·Linghe Zhang·Aneesh Garg·Francis Y. Yan·Elizabeth Belding
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Abstract

Low Latency, Low Loss, and Scalable Throughput (L4S) is an emerging paradigm for latency control based on DualPI2 active queue management and scalable congestion control. While a Linux kernel implementation of DualPI2 is available, controlled and reproducible experimentation on L4S mechanisms can be facilitated by a modular, user-space alternative. In this paper, we present a DualPI2 module for the Mahimahi network emulator, designed to support extensible, component-level experimentation without kernel modification. We conduct a statistical behavioral characterization of the Mahimahi implementation by examining key metrics across diverse traffic patterns and network conditions, using the Linux kernel implementation as a reference baseline. Our analysis shows that behavioral alignment across execution environments is not automatic: identical DualPI2 parameterization does not guarantee identical dynamics. Instead, key control parameters exhibit environment-dependent sensitivity, leading to regime-dependent discrepancies across bandwidth-delay product (BDP) conditions. Through targeted parameter exploration, we identify configurations that improve cross-platform alignment in low BDP regimes, while revealing structural differences that persist under higher load. This work provides both a practical tool for experimental L4S research and empirical insight into cross-platform behavioral differences, highlighting the importance of systematic characterization and environment-aware parameter selection in emulation-based AQM studies.

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Nawel Alioua, Linghe Zhang, Aneesh Garg, Francis Y. Yan, Elizabeth Belding. 2026-07-26. A DualPI2 Module for Mahimahi: Behavioral Characterization and Cross-Platform Analysis. https://arxiv.org/abs/2603.04381

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