Barath Raghavan, who was at ICSI from 2010 to 2012, has rejoined ICSI's Networking and Security team to work with Scott Shenker, ICSI's chief scientist, director of Research Initiatives, Networking and Security researcher, and UC Berkeley professor.  In his first tenure here, Barath's research focused on Internet architecture, but this time he will work on problems related to software-defined networking (SDN).

Barath received his bachelor’s degree from UC Berkeley in 2002. He went on to graduate school at UC San Diego on a National Science Foundation Graduate Research Fellowship and received his doctorate in 2009. After that, he was a visiting assistant professor of computer science at Williams College in Massachusetts before joining ICSI in 2010. After his two years here, he was at Google, and is now back at ICSI working closely with Scott and his students. He will focus on refining and fixing problems with SDN, which was developed from Scott's work with colleagues at Stanford.

In traditional networks, each piece of hardware is independent to a degree. This makes it difficult to establish global policies and to debug and manage large networks. In SDN, one of the major research successes in networking of the last 10 years, each piece of hardware has little knowledge or understanding of what the network as a whole is doing while a central software-based controller orchestrates their actions. As a result, networks become, at least in theory, easier to manage centrally and also more resistant to failure.

However, SDNs come with their own challenges, including a single failure point that can take an entire network down and problems maintaining consistency throughout the network. At ICSI, Barath will be working on one project that is developing a system for debugging SDN and distributed systems; in another, researchers are planning the next generation of SDN.

While at ICSI the first time, Barath also worked on sustainability issues, green networking, and related topics. He co-wrote a paper that won the best paper award at a SIGCOMM 2011 workshop on green networking; another paper estimated how much energy the Internet uses. He also worked on a study of the material dependencies of the Internet -- not just how much energy it uses, but also what physical resources are necessary to build devices, connect them to the Internet, and so on. This study attempted to trace computer communication down to its basic material elements. He may continue working on these issues at ICSI going forward.

In addition to his position here, he will work with a nonprofit startup, DeNovo, that develops technology for freer communication. In one project, Barath will develop better techniques to provide Internet access to rural areas; in another, he will be working on censorship-resistant communication for citizens of repressive regimes.

Barath is perhaps best known at ICSI, though, for the rooftop garden that he started while here the first time. For most of his time at Google, he visited regularly to care for the plants, and we were eating cherry tomatoes for months thanks to him. Now that he's back with us, he hopes to revive the garden.