December 2, Monday
12:00pm-12.45pm Registration & Lunch
12.45pm-1:15pm Introductions: Nick McKeown
1:15pm-2:00pm Keynote: Frank Kelly (University of Cambridge)


Appropriate buffer sizes in a communication network depend intimately on the control algorithms and feedback mechanisms deployed across the network and its end-points. Nevertheless there are certain general principles that provide insight into what is, and what is not, possible.

Buffers in a communication network serve at least two essential purposes. They are needed to cope with: the randomness inherent in the multiplexing of many flows; and the speed of light propagation delays that necessarily constrain source responses to congestion. The talk will begin with an analysis of how queueing delays scale under regimes of increasing speed, volume and multiplexing. It is not a surprise that under a variety of scaling regimes queueing delays become small in comparison with propagation delays.

Congestion control algorithms cannot avoid propagation delays, and this limits their speed of response to feedback signals. Robust algorithms need to be stable for general topologies with multiple constrained resources, and ways of achieving this are now well understood. If feedback based on rate mismatch is available, then feedback based on queue size is not useful for stabilizing long-lived flows. Feedback based on queue size is however important for clearing transient overloads caused by, for example, incasts or failures. If feedback based on rate mismatch is available, then buffer sizes should primarily be determined by potential transient overloads.


Frank Kelly is Professor of the Mathematics of Systems in the University of Cambridge. His main research interests are in random processes, networks and optimization. He is especially interested in applications to the design and control of networks and to the understanding of self-regulation in large-scale systems.

He is a Fellow of the (UK) Royal Society and a Foreign Member of the (US) National Academy of Engineering. He was awarded the IEEE Alexander Graham Bell Medal for his work on mathematical foundations for a scientific understanding of fundamentally important network phenomena.

2:00pm-3:00pm Session 1
Session Chair: Yashar Ganjali
A Principled Look at the Utility of Feedback in Congestion Control Mohit P. Tahiliani (National Institute of Technology Karnataka, Surathkal, India), Vishal Misra (Columbia University, New York), K. K. Ramakrishnan (University of California, Riverside)
Switches Know the Exact Amount of Congestion Serhat Arslan (Stanford University), Nick McKeown (Stanford University)
Buffer sizing with HPCC Rui Miao (Alibaba Group), Bo Li (Alibaba Group), Hongqiang Harry Liu (Alibaba Group), Ming Zhang (Alibaba Group)
3:00pm-3:30pm Break
3:30pm-4:15pm Interview Panel #1
4:15pm-5:15pm Session 2
Session Chair: Renata Teixeira
Understanding switch buffer utilization in CLOS data center fabric Yihua He (Verizon Media Group), Igor Gashinsky (Verizon Media Group), Nitin Batta (Verizon Media Group)
Buffer sizing and Video QoE Measurements at Netflix Bruce Spang (Stanford University), Brady Walsh (Netflix), Te-Yuan Huang (Netflix), Tom Rusnock (Netflix), Joe Lawrence (Netflix), Nick McKeown (Stanford University)
Buffer Sizing Experiments at Facebook Neda Beheshti (Facebook), Omar Baldonado (Facebook), Petr Lapukhov (Facebook), Yashar Ganjali (University of Toronto)
5:15pm-6:00pm Interview Panel #2
6:00pm-8:00pm Reception
December 3, Tuesday
8:30am Registration & Breakfast
9:00am-10:00am Session 3
Session Chair: Vishal Misra
Measuring Burstiness in Data Center Applications Jackson Woodruff (University of Edinburgh), Andrew W. Moore (University of Cambridge), Noa Zilberman (University of Cambridge)
Buffer sizing problems in networks and asynchronous circuits: similarities and differences Rajit Manohar (Yale University), Robert Soulé (Yale University)
Who will Save the Internet from the Congestion Control Revolution? Ferenc Fejes (Eötvös Loránd University), Gergő Gombos (Eötvös Loránd University), Sándor Laki (Eötvös Loránd University), Szilveszter Nádas (Ericsson)
10:00am-10:45am Interview Panel #3
10:45am-11:15am Break
11:15am-12:15pm Session 4
Session Chair: Christophe Diot
Using Packet Trimming at Forwarding Nodes to Reduce Buffer Sizes Cedric Westphal (Futurewei), kiran makhijani (Futurewei), Richard Li (Futurewei)
On estimating the number of flows Bruce Spang (Stanford University), Nick McKeown (Stanford University)
Queueing at the Telco Service Edge: Requirements, Challenges and Opportunities Ralf Kundel (TU Darmstadt), Joerg Wallerich (Deutsche Telekom Technik GmbH), Wilfried Maas (Deutsche Telekom Technik GmbH), Leonhard Nobach (Deutsche Telekom Technik GmbH), Boris Koldehofe (TU Darmstadt), Ralf Steinmetz (TU Darmstadt)
Measuring Queues in Campus Network via Link Tapping Xiaoqi Chen (Princeton University), Hyojoon Kim (Princeton University)
Buffering at the edge: measuring from home networks Daniel Atkinson (UFRJ), Gustavo Santos (UFRJ), Gaspare Bruno (UFRJ), Edmundo de Souza e Silva (UFRJ), Renata Teixeira (INRIA)
Buffer Sizing: a Position Paper Matthew Mathis (Google), Andrew McGregor
12:15pm-1:15pm Lunch
1:15pm-2:15pm Session 5
Session Chair: Hugh Holbrook
Cocoa: Congestion Control Aware Queuing Maximilian Bachl (Technische Universität Wien), Joachim Fabini (Technische Universität Wien), Tanja Zseby (Technische Universität Wien)
Impact of Buffer Size on a Congestion Control Algorithm Based on Model Predictive Control Taran Lynn (University of California, Davis), Nathan Hanford (University of California, Davis), Dipak Ghosal (University of California, Davis)
Backpressure Flow Control Prateesh Goyal (MIT CSAIL), Preey Shah (IIT Bombay), Naveen Kumar Sharma (University of Washington), Mohammad Alizadeh (MIT CSAIL), Thomas Anderson (University of Washington)
2:15pm-2:45pm Break
2:45pm-3:45pm Session 6
Session Chair: Nick McKeown
FAB: Toward Flow-aware Buffer Sharing on Programmable Switches Maria Apostolaki (ETH Zurich), Laurent Vanbever (ETH Zurich), Manya Ghobadi (MIT)
P4-enabled Network-assisted Congestion Feedback: A Case for NACKs Anja Feldmann (MPI for Informatics), Emilia Ndilokelwa Weyulu (MPI für Informatik), Seifeddine Fathalli (MPI für Informatik), Balakrishnan Chandrasekaran (MPI für Informatik)
Fine-grained P4 Measurement Toolkit for Carrier Grade Networks Ken Duell (AT&T), Kathy Meier-Hellstern (AT&T), Jen Rexford (Princeton University)
3:45pm-4:15pm Closing Remarks

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