@article{ganji_shahzad_2021, title={Characterizing the Performance of QUIC on Android and Wear OS Devices}, ISSN={["1095-2055"]}, DOI={10.1109/ICCCN52240.2021.9522258}, abstractNote={Google’s QUIC protocol has become popular over the past few years and is being rapidly adopted as the transport protocol of choice by popular Internet services in their mobile applications. Considering this, it is crucial to understand the performance and implementation issues of integrating QUIC with mobile and wearable applications. In this paper, we conduct a comprehensive measurement analysis and comparison of QUIC with TCP on mobile and wearable platforms. Our experiments cover a wide range of environments, including different request sizes, traffic directions, and connectivity types. From our experiments, we found that the benefits of using QUIC instead of TCP to service HTTP requests are not uniform across different scenarios. We also found a bug in the current implementation of QUIC in Android’s Cronet library that prevents the applications from reverting back to using WiFi after a connection migration from LTE happens. Our experiences from this measurement study has lead us to propose a probabilistic framework, which we call Dynamic Transport Selection, that adaptively chooses the appropriate transport protocol for a given network environment. We implemented and evaluated this framework in Android and Wear OS devices and found that it improves the overall request completion performance of the application by as much as 41.76% when compared to using either QUIC or TCP alone}, journal={30TH INTERNATIONAL CONFERENCE ON COMPUTER COMMUNICATIONS AND NETWORKS (ICCCN 2021)}, author={Ganji, Anirudh and Shahzad, Muhammad}, year={2021} }
 @article{ganji_singh_shahzad_2020, title={Characterizing the Impact of TCP Coexistence in Data Center Networks}, ISSN={["1063-6927"]}, DOI={10.1109/ICDCS47774.2020.00035}, abstractNote={The switch fabrics of today’s data centers carry traffic controlled by a variety of TCP congestion control algorithms. This leads us to ask: how does the coexistence of multiple variants of TCP on shared switch fabric impacts the performance achieved by different applications in data centers? To answer this question, we conducted an extensive set of experiments with coexisting TCP variants on Leaf-Spine and Fat-Tree switch fabrics. We executed common data center workloads, which include streaming, MapReduce, and storage workloads, using four commonly used TCP variants, namely BBR, DCTCP, CUBIC, and New Reno. We also extensively executed iPerf workloads using these 4 TCP variants to purely study the impact of the coexistence of TCP variants on each other’s performance without incorporating the network behavior of the application layer. Our experiments resulted in a large set of network traces comprised of 160 billion packets (we will release these traces after publication of this work). We present comprehensive observations from these traces that have important implications in ensuring optimal utilization of data center switch fabric and in meeting the network performance needs of application layer workloads.}, journal={2020 IEEE 40TH INTERNATIONAL CONFERENCE ON DISTRIBUTED COMPUTING SYSTEMS (ICDCS)}, author={Ganji, Anirudh and Singh, Anand and Shahzad, Muhammad}, year={2020}, pages={388–398} }