This paper introduces the Differentiated Services Resource Updating Protocol (DSRUP), a resource management protocol to be implemented in a DiffServ environment. The protocol makes use of periodic updating information sent from the egress edge of the DiffServ domain. Changes are made to this information as it passes through interior nodes to reflect the current resource conditions in the domain. Ingress nodes will make use of this information to make informed resource management decisions of traffic entering the domain. Initial simulation tests show that the protocol is able to provide better resource utilization when compared with conventional DiffServ.