QAware: A Cross-Layer Approach to MPTCP Scheduling

TL;DR

QAware is a cross-layer MPTCP scheduler that improves performance by combining end-to-end delay estimates with local queue information, leading to better resource utilization and higher throughput.

Contribution

It introduces QAware, a novel cross-layer MPTCP scheduler that leverages local device driver queue data alongside traditional path metrics for improved decision-making.

Findings

QAware outperforms existing schedulers in simulations and real experiments.

It achieves higher aggregate throughput across various network conditions.

The approach adapts more quickly to changing network states.

Abstract

Multipath TCP (MPTCP) allows applications to transparently use all available network interfaces by creating a TCP subflow per interface. One critical component of MPTCP is the scheduler that decides which subflow to use for each packet. Existing schedulers typically use estimates of end-to-end path properties, such as delay and bandwidth, for making the scheduling decisions. In this paper, we show that these scheduling decisions can be significantly improved by incorporating readily available local information from the device driver queues in the decision-making process. We propose QAware, a novel cross-layer approach for MPTCP scheduling. QAware combines end-to-end delay estimates with local queue buffer occupancy information and allows for a better and faster adaptation to the network conditions. This results in more efficient use of the available resources and considerable gains in aggregate throughput. We present the design of QAware and evaluate its performance through simulations, and also through real experiments, comparing it to existing schedulers. Our results show that QAware performs significantly better than other available approaches for various use-cases and applications.