Enhancing QUIC over Satellite Networks

The use of Satellite Communication (SATCOM) networks for broadband connectivity has recently seen an increase in popularity due to, among other factors, the rise of the latest generations of cellular networks (5G/6G) and the deployment of high-throughput satellites. In parallel, major advances have been witnessed in the context of the transport layer: first, the standardization and early deployment of QUIC, a new-generation and general-purpose transport protocol; and second, modern congestion control proposals such as the Bottleneck Bandwidth and Round-trip propagation time (BBR) algorithm. Even though satellite links introduce several challenges for transport layer mechanisms, mainly due to their long propagation delay, satellite Internet providers have relied on TCP connection-splitting solutions implemented by Performance-Enhancing Proxies (PEPs) to greatly overcome many of these challenges. However, due to QUIC's fully encrypted nature, these performance-boosting solutions become nearly impossible for QUIC traffic, leaving it in great disadvantage when competing against TCP-PEP. In this context, IETF QUIC WG contributors are currently investigating this matter and suggesting new solutions that can help improve QUIC's performance over SATCOM. This thesis aims to study some of these proposals and evaluate them through experimentation using a real network testbed and an emulated satellite link

Reducing the acknowledgement frequency in IETF QUIC

Research Funding European Space Agency University of AberdeenPeer reviewedPublisher PD

Google QUIC performance over a public SATCOM access

Google QUIC accounts for almost 10 % of the Internet traffic and the protocol is not standardized at the IETF yet. We distinguish Google QUIC (GQUIC) and IETF QUIC (IQUIC) since there may be differences between the two. Both Google and IETF versions run over UDP and cannot be split the way satellite systems usually do with TCP connections. The need for adapting any-QUIC parameters needs to be evaluated. Since GQUIC is available, we analyze its behavior over a satellite communication system. In our evaluations, GQUIC quick connection establishment does not compensate an inappropriate congestion control. The resulting page downloading time doubles when using GQUIC as opposed to the performance with optimized split TCP connections. This paper concludes that specific tuning are required when any-QUIC runs over a high BDP network

QUIC: Opportunities and threats in SATCOM

This article proposes a discussion on the strengths, weaknesses, opportunities, and threats related to the deployment of QUIC end-to-end from a satellite-operator point-of-view. The deployment of QUIC is an opportunity for improving the quality of experience when exploiting satellite broadband accesses. Indeed, the fast establishment of secured connections reduces the transmission time of short files. Moreover, removing transport-layer performance-enhancing proxies reduces the cost of network infrastructures and improves the integration of satellite systems. However, the congestion and flow controls at end points are not always suitable for satellite communications due to the intrinsic high bandwidth-delay product. Further acceptance of QUIC in satellite systems would be guaranteed if its performance in specific use cases were increased. Based on an emulated platform and on open-source software, this paper proposes values of performance metrics as one piece of the puzzle. The final performance objective requires consensus among the different actors. The objective should at least provide acceptable performance for satellite operators to allow QUIC traffic but reasonable enough to keep QUIC deployable on the Internet

A QoS-Based Fairness-Aware BBR Congestion Control Algorithm Using QUIC

Congestion control is a fundamental technology to balance the traffic load and the network. The Internet Engineering Task Force (IETF) Quick UDP Internet Connection (QUIC) protocol has flexible congestion control and at the same time possesses the advantages of high efficiency, low latency, and easy deployment at the application layer. Bottleneck bandwidth and round-trip propagation time (BBR) is an optional congestion control algorithm adopted by QUIC. BBR can significantly increase throughput and reduce latency, in particular over long-haul paths. However, BBR results in high packet loss in low bandwidth and low fairness in multi-stream scenarios. In this article, we propose the enhanced BBR congestion control (eBCC) algorithm, which improves the BBR algorithm in two aspects: (1) 10.87% higher throughput and 74.58% lower packet loss rate in the low-bandwidth scenario and (2) 8.39% higher fairness in the multi-stream scenario. This improvement makes eBCC very suitable for IoT communications to provide better QoS services

Consistent high performance and flexible congestion control architecture

The part of TCP software stack that controls how fast a data sender transfers packets is usually referred as congestion control, because it was originally introduced to avoid network congestion of multiple competing flows. During the recent 30 years of Internet evolution, traditional TCP congestion control architecture, though having a army of specially-engineered implementations and improvements over the original software, suffers increasingly more from surprisingly poor performance in today's complicated network conditions. We argue the traditional TCP congestion control family has little hope of achieving consistent high performance due to a fundamental architectural deficiency: hardwiring packet-level events to control responses. In this thesis, we propose Performance-oriented Congestion Control (PCC), a new congestion control architecture in which each sender continuously observes the connection between its rate control actions and empirically experienced performance, enabling it to use intelligent control algorithms to consistently adopt actions that result in high performance. We first build the above foundation of PCC architecture analytically prove the viability of this new congestion control architecture. Specifically, we show that, controversial to intuition, with certain form of utility function and a theoretically simplified rate control algorithm, selfishly competing senders converge to a fair and stable Nash Equilibrium. With this architectural and theoretical guideline, we then design and implement the first congestion control protocol in PCC family: PCC Allegro. PCC Allegro immediate demonstrates its architectural benefits with significant, often more than 10X, performance gain on a wide spectrum of challenging network conditions. With these very encouraging performance validation, we further advance PCC's architecture on both utilty function framework and the learning rate control algorithm. Taking a principled approach using online learning theory, we designed PCC Vivace with a new strictly socially concave utility function framework and a gradient-ascend based learning rate control algorithm. PCC Vivace significantly improves performance on fast-changing networks, yields better tradeoff in convergence speed and stability and better TCP friendliness comparing to PCC Allegro and other state-of-art new congestion control protocols. Moreover, PCC Vivace's expressive utility function framework can be tuned differently at different competing flows to produce predictable converged throughput ratios for each flow. This opens significant future potential for PCC Vivace in centrally control networking paradigm like Software Defined Networks (SDN). Finally, with all these research advances, we aim to push PCC architecture to production use with a a user-space tunneling proxy and successfully integration with Google's QUIC transport framework

QUIC on the Highway: Evaluating Performance on High-rate Links

QUIC is a new protocol standardized in 2021 designed to improve on the widely used TCP / TLS stack. The main goal is to speed up web traffic via HTTP, but it is also used in other areas like tunneling. Based on UDP it offers features like reliable in-order delivery, flow and congestion control, streambased multiplexing, and always-on encryption using TLS 1.3. Other than with TCP, QUIC implements all these features in user space, only requiring kernel interaction for UDP. While running in user space provides more flexibility, it profits less from efficiency and optimization within the kernel. Multiple implementations exist, differing in programming language, architecture, and design choices. This paper presents an extension to the QUIC Interop Runner, a framework for testing interoperability of QUIC implementations. Our contribution enables reproducible QUIC benchmarks on dedicated hardware. We provide baseline results on 10G links, including multiple implementations, evaluate how OS features like buffer sizes and NIC offloading impact QUIC performance, and show which data rates can be achieved with QUIC compared to TCP. Our results show that QUIC performance varies widely between client and server implementations from 90 Mbit/s to 4900 Mbit/s. We show that the OS generally sets the default buffer size too small, which should be increased by at least an order of magnitude based on our findings. Furthermore, QUIC benefits less from NIC offloading and AES NI hardware acceleration while both features improve the goodput of TCP to around 8000 Mbit/s. Our framework can be applied to evaluate the effects of future improvements to the protocol or the OS.Comment: Presented at the 2023 IFIP Networking Conference (IFIP Networking