Various embodiments described herein aim to ensure that user data transmissions (e.g., small data transmissions that are sent using control plane messages) do not become excessive and stay infrequent, thereby reducing the likelihood of a network overload situation. In one embodiment, an admission control function (ACF) for regulating the transmission of uplink user data is implemented in a wireless communication device (WCD) (e.g., a CIoT device). Such a WCD device may receive from a core serving node (CSN) admittance information (AI) (e.g., parameters, such as thresholds, used by the ACF to regulate the uplink traffic) that is used in performing the admittance control.