George Varghese

Principal Researcher, Microsoft Research

January 8th, 2016, 11am-12pm, DBH 6011


Network Verification and Synthesis - When Hoare Meets Cerf


Surveys reveal that network outages are prevalent, and that many outages take hours to resolve, resulting in significant lost revenue. Many bugs are caused by errors in configuration files which are programmed using arcane, low-level languages, akin to machine code. Taking our cue from program and hardware verification, we suggest fresh approaches. I will first describe a geometric model of network forwarding called Header Space. While header space analysis is similar to finite state machine verification, we exploit domain-specific structure to scale better than off-the shelf model checkers. Next, I show how to exploit physical symmetry to scale network verification for large data centers. While Emerson and Sistla showed how to exploit symmetry for model checking in 1996, they exploited symmetry on the logical Kripke structure. While the first part of the talk is about analysis, I will then describe our work in synthesis. I will set the stage by describing a new re-configurable router architecture we proposed called RMT This has led to an emerging language for programming routers called P4 that promises to extend the boundaries of Software Designed Networks. I will then describe a synthesis problem for flexible routers, akin to code generation (packet transactions) and new algorithmic questions related to synthesizing routes in the face of uncertainty. (With collaborators at Edinburgh, MSR, MIT, Stanford, and University of Washington.)

Speaker Bio:

George Varghese received his Ph.D. in 1992 from MIT. From 1993-1999, he was a professor at Washington University, and at UCSD from 1999 to 2013. He was the Distinguished Visitor in the computer science department at Stanford University from 2010-2011. He joined Microsoft Research in 2012. His book "Network Algorithmics" was published in December 2004 by Morgan-Kaufman. In May 2004, he co-founded NetSift, which was acquired by Cisco Systems in 2005. With colleagues, he has won best paper awards at SIGCOMM (2014), ANCS (2013), OSDI (2008), PODC (1996), and the IETF Applied Networking Prize (2013). He has won lifetime achievement awards in networking from the EE community (2014 Kobayashi Award) and the CS Community (2014 SIGCOMM Award). He won the IIT Bombay Distinguished Alumni Award in 2015.