1. A method of evaluating the reliability of a route in a cooperative network for transmitting packets of data between a source node and a destination node of the network, comprising, on reception by the destination node of a message indicating a route between the two nodes: a step of evaluating a reliability indicator parameter value for the indicated route based on stored trust indices respectively associated with nodes in the indicated route; a step of associating the indicated route with the reliability indicator parameter value evaluated by the destination node; and a step of sending the source node a response including the reliability indicator parameter value associated with the indicated route, wherein the reliability indicator parameter value associated with the indicated route is evaluated based on information administered by the destination node relating to nodes of the network, said information comprising at least one of a load index of a node in the indicated route and a network structure index, wherein the load index increases when contribution to communications by the node increases, and the reliability indicator parameter value for the indicated route decreases when the load index increases, and wherein the network structure index increases when a number of operator administered nodes, through which the indicated route passes, increases, and the reliability indicator parameter value for the indicated route increases when the network structure index increases.