I am interested in Network problems rooted on (what most people would call) reality, but from which a fundamental concept can also be extracted, or to which one can be applied. Normally, these fundamental concepts are expressible in some language within the realm of mathematics (logics, at least): I focus much on understanding and on reasoning about Networks.

In recent years, I have been mostly involved in Network Routing, as substantiated by the protocols of the Internet. Here are some of the questions that got me motivated.

• Under what conditions do routing policies implemented at Internet Service Providers (ISPs) assure a proper behavior of the Border Gateway Protocol (BGP) that glues them together, and, by inherence, of the Internet? What routing policies are currently being applied at ISPs? 

• What is the overall connectivity/reliability provided by routing policies in the decentralized environment of the Internet, composed of thousand of ISPs, competing as well as collaborating among themselves?

• How do we design route aggregation strategies to scale networks, either ISPs or the Internet as a whole? How should they be designed with minimal loss to the connectivity and the performance of an ISP? How should they be designed all the while respecting the existing routing policies among ISPs?

• What are good architectures for an IPTV service? IP protocols were designed neither for large-scale multicast nor for hard delay-bounds on delivery.  How best to provide protection and recovery in IPTV networks?