A game theoretic analysis of protocols based on fountain codes

In this paper we analyze a novel paradigm of reliable communications which is not based on the traditional timeout-and-retransmit mechanism of TCP. Our approach, which we call FBP (fountain based protocol), consists on using a digital fountain encoding which guarantees that duplicate packets are not possible. Using game theory, we analyze the behavior of TCP and FBP in the presence of congestion. We show that hosts using TCP have an incentive to switch to an FBP approach obtaining a higher throughput. Furthermore, we also show that a Nash equilibrium takes place when all hosts use FBP. At this equilibrium, the performance of the network is similar to the performance obtained when all hosts comply with TCP.