— In this paper we consider packet networks loaded by admissible traffic patterns, i.e. by traffic patterns that, if optimally routed, do not overload network resources. In these conditions, we study the combined behavior of distributed dynamic routing and scheduling algorithms based upon link state information, with no knowledge of the average traffic pattern, and we prove that simple schemes can achieve the same network throughput as optimal centralized routing and scheduling algorithms with complete information on the traffic pattern. y is based on a flow-level abstract model of the network, and considers elastic traffic, i.e., we assume that flows can adapt their transmission rates to network conditions. As a result, our model captures some of the main features of Internet traffic and of quality-of-service routing approaches being currently proposed for IP networks. We show that efficient dynamic routing and scheduling algorithms can be implemented in a distributed way, ...