Section: Contracts and Grants with Industry

Collaboration with France Telecom (CRC Mardi)

Participants : Diego Perino, Dmitry Lebedev [ France Telecom R&D, Issy Les Moulineaux, France ] , Fabien Mathieu [ France Telecom R&D, Issy Les Moulineaux, France ] , Fabien de Montgolfier, Julien Reynier, Laurent Viennot, Simon Gwendal [ France Telecom R&D, Issy Les Moulineaux, France ] .

MARDI is a collaboration contract between Inria and France Telecom. It gathers Gang and Spontex (FT) around the study of decentralized networks over Internet. Spontex is a transversal project on cooperative networks. Diego Perino is funded through this collaboration and co-supervised by Fabien Mathieu and Laurent Viennot.

Measuring Internet with and for peer-to-peer networks

A first aspect of the project consist in studying Internet latencies in order to understand how logical overlays can be optimized with respect to delays. A possible track for gathering valuable large scale measures is to use a peer-to-peer network for measuring latencies. Interestingly, it is possible to find shortcuts in the Internet where the route through a relay can be faster than the direct route.

Modeling node and connection dynamics

This item is connected to the affinity model where peers tend to connect preferentially to some peers based on some measured or inferred criteria. Connecting peers according to delays is a special case of affinity where a peer connects preferentially to peers with low RTT. Additional properties can be proven for this case to prove the convergence of a dynamic system following this low RTT strategy.

Peer-to-peer application design

The third part of the project aims at designing efficient structuring algorithm for decentralized applications. It relies on the previous parts. Measuring and modeling Internet latencies can be used to obtain a first coarse solution to a fast overlay, and the affinity models can be use to tune the solution and to adapt it under node churn.