There exists an increasing need for dynamic mechanisms that take into account quality of service provisions in the establishment of routes in communication networks. Recently, we introduced a quality of service (QoS) driven routing algorithm called "Cognitive Packet Network" (CPN), which dynamically selects paths through a store-and-forward packet network so as to offer best effort QoS to an end-to-end traffic. This paper discusses a number of extensions to the algorithm: the incorporation of selective broadcasts to support the operation of an ad hoc network, the use of delay, loss, and energy information as metrics for routing, and the use of genetic algorithms to generate and maintain paths from previously discovered information by matching their "fitness" with respect to the desired QoS. We discuss implementation considerations as well as simulation and experimental results on a network testbed. © Springer-Verlag Berlin Heidelberg 2004.