A network exposure function receives, from an application function, a first message requesting delivery of one or more Internet of Things (IoT) packets to a wireless device. The network exposure function sends, to a network repository function, a second message requesting a discovery of a user plane function that supports cellular IoT optimization. The network exposure function receives, from the network repository function, a third message comprising an identifier of the user plane function that supports the cellular IoT optimization. The network exposure function sends, to the user plane function, a fourth message requesting delivery of the one or more IoT packets to the wireless device.