In mobile ad hoc networks, protocols are distributed and rely on the cooperative participation of all nodes in the network. Since the wireless technology implies node resource constraints, it may not be convenient for a node to relay requests on behalf of others. Also, malicious nodes may intentionally damage network functioning by not cooperating. Thus, cooperative algorithms make the system vulnerable to users as well as to malicious and selfish misbehavior. Lack of cooperation may severely degrade the performance of the ad hoc system; noncooperative nodes may partition the network, and well-behaving nodes can be overburdened by the consequent deviation of most of the traffic on to them, leading to possible congestion events. We address the issues of performance and reliability in packet forwarding. Our approach is based on reliability estimators taking into account not only selfish and malicious misbehavior, but also situations of congestion and lossy links. We aim at increasing network throughput and avoiding unreliable routes, thus increasing network "performability" (performance and reliability).
