An individual session border controller in a cluster of SBCs, e.g., in a Cloud, sends a resource utilization reporting message to the current master resource manager for the cluster. In response to the received utilization reporting message from the individual SBC, the master resource manager determines a mode of operation, e.g. one of: normal, critical or overshoot, for the cluster and a resource allocation for the SBC, the resource allocation method used being different for at least two different modes. The master resource manager communicates the determined cluster mode and the determined resource allocation to the individual SBC, e.g., in a response message. The SBC controls its resource utilization reporting rate as a function of the mode. In at least one mode, e.g., normal mode, the SBC is allowed to use more resources, e.g., X % more, than the amount of resources allocated to the SBC by the master resource manager.