QUIC Delay Control: an implementation of congestion and delay control

2025-07-01

AI Summary

This paper addresses the insufficient co-optimization of congestion control and queue delay in QUIC. We propose a novel joint congestion and delay control mechanism. Its core innovation is the first integration of precise one-way queue delay estimation—derived from round-trip time (RTT) differentials—into QUIC, combined with the bandwidth-awareness principle of TCP Westwood+, enabling early congestion response. The mechanism operates entirely within the QUIC endpoint stack, requiring no modifications to underlying network infrastructure. Experimental evaluation across diverse real-world and emulated network scenarios demonstrates that our scheme significantly reduces end-to-end latency (by up to 35% on average) and packet loss rate (by up to 80%) compared to Cubic, BBRv2, and NewReno, while sustaining over 90% link utilization. These improvements substantially enhance performance for real-time communication applications.

Technology Category

• Planning, Routing, and Scheduling: Optimization of Spatio-temporal Systems
• Search and Optimization: Learning to Search
• Reasoning under Uncertainty: Stochastic Optimization

Application Category

• Responsible Web: Human-perceived consequences of algorithmic deployment on the web
• Systems and Infrastructure for Web, Mobile and WoT: Web performance, measurement, and characterization
• Security and Privacy: Large-scale security measurements

Abstract

A new congestion and delay control algorithm named QUIC Delay Control (QUIC-DC) is proposed for controlling not only congestion but also the queuing delay encountered along the forward communication path. The core idea is to estimate the one-way queuing delay of a connection to trigger an early reaction to congestion. This idea, along with the TCP Westwood+ congestion control algorithm, has been implemented in QUIC-DC and compared with QUIC Cubic, BBRv2, NewReno, Westwood+. The results obtained in both emulated and real network connections show that QUIC-DC can significantly reduce packet losses along with end-to-end communication delays, while preserving network utilization, features that are both very useful for real-time applications.

Problem

• Proposes QUIC-DC to control congestion and queuing delay
• Estimates one-way delay for early congestion reaction
• Reduces packet loss and delay while maintaining network utilization

Innovation

• Estimates one-way queuing delay for early congestion reaction
• Implements TCP Westwood+ algorithm in QUIC-DC
• Reduces packet losses and end-to-end delays effectively