MPTCP meets FEC: Supporting Latency-Sensitive Applications over Heterogeneous Networks

TL;DR

This paper introduces a novel TCP framework with integrated forward error correction (FEC) to improve latency-sensitive application performance over lossy, high-delay, and heterogeneous networks, especially within multipath TCP (MPTCP).

Contribution

It designs and implements an FEC-integrated TCP framework, enhancing MPTCP performance in heterogeneous networks for latency-sensitive applications.

Findings

Significant performance improvements over legacy TCP and MPTCP.

Enhanced support for latency-sensitive applications like video streaming.

Effective reduction of retransmission delays in lossy, high-delay networks.

Abstract

Over the past years, TCP has gone through numerous updates to provide performance enhancement under diverse network conditions. However, with respect to losses, little can be achieved with legacy TCP detection and recovery mechanisms. Both fast retransmission and retransmission timeout take at least one extra round trip time to perform, and this might significantly impact performance of latency-sensitive applications, especially in lossy or high delay networks. While forward error correction (FEC) is not a new initiative in this direction, the majority of the approaches consider FEC inside the application. In this paper, we design and implement a framework, where FEC is integrated within TCP. Our main goal with this design choice is to enable latency sensitive applications over TCP in high delay and lossy networks, but remaining application agnostic. We further incorporate this design into multipath TCP (MPTCP), where we focus particularly on heterogeneous settings, considering the fact that TCP recovery mechanisms further escalate head-of-line blocking in multipath. We evaluate the performance of the proposed framework and show that such a framework can bring significant benefits compared to legacy TCP and MPTCP for latency-sensitive real application traffic, such as video streaming and web services.