This work presents an admission control mechanism to be used with mapping mechanisms between Integrated Services (ZntServ) and Dzferentiated Services (DiffServ) domains. The mapping mechanisms have a dynamic nature and are associated with the admission control functions in such a way that the state of the network is reflected in the admission decisions of new IntServ flows into the Dzmerv network. The work is focused in the mapping between the ZntSew Controlled-Load (CL) service and the DifJServ Assured Fonvard (AF) Per-Hop-Behaviour group. The results obtained by simulation, with TCP and UDP traffic and with two AF classes defined, show that the admission control mechanisms acts based on the bandwidth management mechanisms and improves the use of the available resources for a given AF class. The mapping mechanisms detect Quality of Service (QoS) degradation occurrences and once detected the admission control mechanism allows the reestablishment ofAF Class QoS.