In this paper, we present DDQoS, or Distributed Dynamic Quality of Service, a novel architecture which uses QoS-configured routers as a support layer for a distributed approach on policy-based management system. The main purpose of this work is to model and test a distributed framework for globally (in a domain network) controlling QoS traffic classes parameters, in an effort to dynamically reach the best choice for QoS-conditioning parameters in each given situation, on all impacted routers of a network. The model proposed is available for use today, and does not require base changes in the existent network elements but only the configuration of the routers and the installation of some additional components in each one. The architecture answers the needs of adaptation in the network for the generality of multimedia traffic, when the performance of this traffic is threatened by the presence of flows with less strict requisites.