CESG Seminar: Neal Cardwell

Friday, November 3, 2023
10:20 a.m. – 11:10 a.m. (CST)
ETB 1020

Neal Cardwell
Principal Software Engineer | Google

Title: “Congestion Control in the Real World“

Talking Points:

Swift is a delay-based congestion control for datacenters that achieves low latency, high utilization, and near-zero loss.
Swift achieves roughly 50 microsecond tail latency while maintaining near 100% utilization even at 100Gbps line rates.
BBR is a model-based congestion control for wide-area networks that achieves low latency, high utilization, and robustness to a targeted level of random packet loss.
BBR avoids bufferbloat (maintaining bounded queues in buffers of any depth), while maintaining near 100% utilization even at the moderate loss rates characteristic of today’s high-speed, shallow-buffered WANs with bursty short flows.

Abstract
Designing and deploying new high-performance congestion control algorithms at scale in today’s high-speed, real-world datacenter and wide-area networks is challenging. This talk will discuss the challenges in these environments, and then focus on the high-performance congestion control algorithms we have created and deployed at global scale at Google: Swift for datacenter congestion control, and BBR for wide-area congestion control. The talk will close with thoughts on interesting research questions and potential future research directions for real-world congestion control.

Biography
Neal Cardwell is a Principal Software Engineer in Google’s NYC office. He entered the UC Berkeley PhD program in 1996 and then followed his advisor, Tom Anderson, to the University of Washington, where he completed an MS in 1999, with research in the area of TCP congestion control. He worked at Steve McCanne’s FastForward Networks from 1999 to 2002. He has worked at Google since 2002, on projects including GFE (the Google Front End proxying all traffic for google.com), Googlebot (Google’s web crawler), routing performance, the open source Packetdrill network stack testing tool, and Linux TCP congestion control and loss recovery. He is currently a member of the Congestion Control team at Google, and his recent focus has been on improving the BBR and Swift congestion control algorithms.

More Information on Neal Cardwell: https://research.google/people/NealCardwell/