Publications

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Conference Papers

BBRv3 in the public Internet: a boon or a bane?

Published in Proceedings of the Applied Networking Research Workshop, 2024

The third version of the Bottleneck-Bandwidth and Round-trip (BBR) algorithm, BBRv3, is now the default CCA for all of the public Internet traffic from google.com and YouTube. In this work, we build upon our prior work and examine BBRv3’s ability to coexist with Cubic flows by taking loss, in the form of explicit congestion notification (ECN) signals, into account. Our evaluations reveal that, when ECN is enabled, a single BBRv3 flow can acquire more than ~99% of the bandwidth even when competing with five Cubic flows. Our findings have crucial implications for using BBRv3 in the public Internet.

Recommended citation: Zeynali, Danesh and Weyulu, Emilia N. and Fathalli, Seifeddine and Chandrasekaran, Balakrishnan and Feldmann, Anja. (2024). "BBRv3 in the public Internet: a boon or a bane?." Proceedings of the Applied Networking Research Workshop.
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Promises and Potential of BBRv3

Published in International Conference on Passive and Active Network Measurement, 2024

The Bottleneck-Bandwidth and Round-trip (BBR) congestion control algorithm was introduced by Google in 2016. Unlike prior congestion-control algorithms (CCAs), BBR does not rely on signals that are weakly correlated with congestion (e.g., packet loss and transient queue delay). Instead, it characterizes a path using two parameters, bottleneck bandwidth and round-trip propagation time, and is designed to converge with a high probability to Kleinrock’s optimal operating point [34]. Essentially, in stable state, BBR maximizes throughput while minimizing delay and loss. Google has used BBR for a significant fraction of its network traffic both within its datacenters and on its WAN since 2017 [15]. BBR’s interaction dynamics with Cubic, the widely used CCA in the Internet, has received intense scrutiny: Some studies observed BBR to be unfair to Cubic, or generally loss-based CCAs. Google, to its credit, has diligently revised BBR’s design to address the criticisms. This paper focuses on characterizing the promises and potential of the third, and most recent, revision of BBR—introduced to the public in July 2023. We empirically evaluate BBRv3’s performance across a range of network scenarios, e.g., considering different buffer sizes, round-trip times, packet losses, and flow-size distributions. We show that despite the improvements and optimizations introduced in BBRv3, it struggles to achieve an equitable sharing of bandwidth when competing with Cubic, the widely used CCA in the Internet, in a wide range of network conditions.

Recommended citation: Zeynali, Danesh, Weyulu, Emilia N., Fathalli, Seifeddine, Chandrasekaran, Balakrishnan, and Feldmann, Anja. (2024). 'Promises and Potential of BBRv3' International Conference on Passive and Active Network Measurement.
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Geographic Routing With Energy Constraint in Wireless Multimedia Sensor Networks

Published in 27th Iranian Conference on Electrical Engineering (ICEE), 2019

Energy distribution for extended network lifetime and non-interfering multipath routing are two major challenges in Wireless Multimedia Sensor Networks (WMSNs) routing. Greedy Perimeter Stateless Routing (GPSR) is a simple routing protocol that uses the minimum geographic distance to forward packets toward the sink node. However, it does not consider energy levels and employs a single path. Geographic Energy-Aware Non-Interfering Multipath Routing (GEAM) addresses this limitation by utilizing multipath routing and energy awareness, but maintaining the state of multiple non-interfering areas incurs overhead. In our proposed routing protocol, called Energy-Aware Greedy Stateless Geographic Routing (EAGSGR), we introduce two-path routing without interference by leveraging only two strategic areas. Additionally, we propose a simple method to handle dead-end nodes and cluster issues. EAGSGR demonstrated better performance compared to GPSR and GEAM in terms of QoS parameters, including end-to-end delay, average hop count, energy distribution, and packet delivery ratio.

Recommended citation: Zeynali Gargary, Danesh, Osali, Fariba, and Afshin Hemmatyar, Ali Mohammad. (2019). "Geographic Routing With Energy Constraint in Wireless Multimedia Sensor Networks" 27th Iranian Conference on Electrical Engineering (ICEE).
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Preprints

A longitudinal view at the adoption of multipath tcp

Published in arXiv preprint, 2022

Multipath TCP (MPTCP) extends traditional TCP to enable simultaneous use of multiple connection endpoints at the source and destination. MPTCP has been under active development since its standardization in 2013, and more recently in February 2020, MPTCP was upstreamed to the Linux kernel. In this paper, we provide an in-depth analysis of MPTCPv0 in the Internet and the first analysis of MPTCPv1 to date. We probe the entire IPv4 address space and an IPv6 hitlist to detect MPTCP-enabled systems operational on port 80 and 443. Our scans reveal a steady increase in MPTCPv0-capable IPs, reaching 13k+ on IPv4 (2× increase in one year) and 1k on IPv6 (40× increase). MPTCPv1 deployment is comparatively low with ≈100 supporting hosts in IPv4 and IPv6, most of which belong to Apple. We also discover a substantial share of seemingly MPTCP-capable hosts, an artifact of middleboxes mirroring TCP options. We conduct targeted HTTP(S) measurements towards select hosts and find that middleboxes can aggressively impact the perceived quality of applications utilizing MPTCP. Finally, we analyze two complementary traffic traces from CAIDA and MAWI to shed light on the real-world usage of MPTCP. We find that while MPTCP usage has increased by a factor of 20 over the past few years, its traffic share is still quite low.

Recommended citation: Shreedhar, Tanya, Zeynali, Danesh, Gasser, Oliver, Mohan, Nitinder, and Ott, Jörg (2022). "A longitudinal view at the adoption of multipath tcp." arXiv. 1(2).
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Danesh Zeynali Gargary