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Stanford University Networking Seminar

Aurojit Panda (NYU/ICSI)
SCL: Simplifying Distributed SDN Control Planes

12:15pm, Thursday, February 15st 2018
Gates 104

About the Talk

We consider the following question: what consistency model is appropriate for coordinating the actions of a replicated set of SDN controllers? We first argue that the conventional requirement of strong consistency, typically achieved through the use of Paxos or other consensus algorithms, is conceptually unnecessary to handle unplanned network updates. We present an alternate approach, based on the weaker notion of eventual correctness, and describe the design of a simple coordination layer (SCL) that can seamlessly turn a set of single-image SDN controllers (that obey certain properties) into a distributed SDN system that achieves this goal (whereas traditional consensus mechanisms do not). We then show through analysis and simulation that our approach provides faster responses to network events. While our primary focus is on handling unplanned network updates, our coordination layer also handles policy updates and other situations where consistency is warranted. Thus, contrary to the prevailing wisdom, we argue that distributed SDN control planes need only be slightly more complicated than single-image controllers.

About the Speaker

Aurojit Panda is currently a software engineer at Nefeli Networks, and starting in August 2018 an assistant professor in computer science at NYU's Courant Institute. He received his PhD in Computer Science from the University of California, Berkeley where he was advised by Scott Shenker. His work spans programming languages, networking and systems, and his recent work has investigated task scheduling in big data systems, network verification, consensus algorithms in software defined networks, and frameworks for building network functions.