His research interests are in computer networks; notably, in designing algorithms for the Internet and for Data Centers. Recently, he has been interested in Societal Networks: networks vital for society's functioning, such as transportation, electricity and recycling systems. He has been involved in developing and deploying incentive mechanisms to move commuters to off-peak times so that congestion, fuel and pollution costs are reduced. He has been a Terman Fellow at Stanford University and a Fellow of the Alfred P. Sloan Foundation. He has received the CAREER award from the U.S. National Science Foundation, the Erlang Prize, the Rollo Davidson Prize, and delivered the Lunteren Lectures in Holland. He is a co-recipient of best paper awards at Hot Interconnects 2002, IEEE Infocom 2004 and ACM Sigmetrics 2008.