Two researchers joined Networking and Security this summer: Philipp Richter and Narseo Vallina-Rodriguez. Philipp is here on a summer internship, working with Networking and Security Director Vern Paxson. We get to keep Narseo a bit longer - he's joined the group as a postdoctoral fellow.

Philipp is a PhD student at Technische Universität Berlin, where he is in his first year. In the past, he has done Internet exchange point (IXP) traffic classification. Here at ICSI, his research focuses on the effects of Internet protocol version 4 (IPv4) address exhaustion. Devices that connect to the Internet are assigned IP addresses. IPv4, the most widely used protocol for addressing in the Internet, is finally running out of unassigned addresses, so another IP standard, IPv6, is being deployed more and more. However, this deployment is going slowly, and some people question how long the transition from IPv4 to IPv6 will take. Switching over to IPv6 imposes some burdens, and there are also methods that have been suggested as alternatives to the new standard, such as technologies that can share a small number of IP addresses among many computers (CGN). Philipp is interested in assessing the transition to IPv6 as well as the effects of address scarcity on currrent IPv4 address usage patterns.

Here at ICSI, and in Berlin, he's been looking at routing information and traffic traces captured at various locations in order to learn more about the effects of IP exhaustion and how Internet services providers are coping with it.

Philipp enjoys travelling. So far, his travels have taken him mostly to Asia, but he's looking forward to a trip through California before he returns to Germany.

Narseo is from Asturias, a northern region in Spain. He attended the University of Oviedo, where he studied telecommunications engineering. He spent the final year of his master's program at the University of Cambridge, working with Professor Jon Crowcroft on Haggle Project. After receiving his degree, he took a nine-month internship at Telefónica Internet Research Group in Spain, working under Pablo Rodriguez. He then returned to Cambridge to work on his PhD. During these years he collaborated closely with Telefónica Research. His thesis, which he defended this June, analyzes cross-layer inefficiencies on mobile systems, from the application level (including back-end infrastructure) to the radio link. In particular, he looked at waste in both energy and spectrum usage attributed to location sensors, mobile advertisement, and background traffic such as long-lived TCP connections required for push notifications. Narseo argued in his thesis that incorporating simple techniques on the operating system to coordinate traffic flows might improve cell phone efficiency without diminishing the user experience. He's generally interested in mobile-cloud optimization - reducing the energy and networking resources required by mobile applications and online services, especially by looking at how middle-boxes, such as proxies, affect efficiency. He's also interested in privacy and its relationship to mobile advertising.

While at ICSI, he will be working with the Netalyzr team. Netalyzr analyzes the extent to which a user's Internet service provider interferes with its customers' traffic. He will be using it to explore networking inefficiencies, especially in mobile networks.