My general area of research is networking, and spans both physical and logical networks. The Internet is a prime example of the former, while social networks are one of many representatives of the latter.
Consequently, my recent projects (see “Current Projects” for details) have been distributed between what I would call “technology-centric” topics, and topics that focus on developing an understanding of the behavior of various phenomena that arise in network settings. On the technology front, I am particularly interested in the aspect of resiliency and how to achieve it in a proactive fashion so as to enable better scalability, i.e., as opposed to reactive schemes that often have difficulty scaling as networks grow large. On the logical network side, many of the issues I have recently looked at belong to what has often been termed “network economics,” i.e., how economic factors affect the development and eventual success of (network) technologies. This originated with an interest in trying to better understand the challenges that IPv6 had been facing, but eventually evolved into seeking a general understanding of how different (market) forces affect network technology adoption, and in particular the role that externalities play.
In a previous life, I also spent a lot of time investigating QoS mechanisms and how to use them to offer performance guarantees. Both topics give rise to a wide range of interesting and challenging problems, and these have been a lot of fun to work on. However, while many of the solutions that were developed are both rigorous and effective, implementing them comes at a cost, and in many settings (in particular in network settings) this cost has often turned out to be eventually higher (as technology improves and as networks get bigger) than simply throwing more resources at the problem. As a result, and except for a few well-defined and scoped environments, QoS solutions have experienced only limited success. Hence, while I still occasionally dabble in QoS related issues, it is not anymore a focus area for my research.