An access and mobility management function (AMF) receives a request to establish a session from a wireless device. A control plane cellular internet of things (CIoT) indication requesting discovery of a session management function (SMF) that supports exchange of user data between the wireless device and the SMF is sent to a network repository function (NRF). An instance of the SMF is received from the NRF. A request to establish the session for CIoT packet transmission is sent to the SMF.