A device can be configured to receive first internet protocol multimedia subsystem (IMS) data from a user device, provide the first IMS registration data to an IMS device, maintain—on behalf of the user device—an IMS connection between the user device and the IMS device. In addition, the device an receive, from the IMS device, an IMS invite addressed to the user device, temporarily hold the IMS invite, provide a push notification device with a push notification request specifying the user device, receive second IMS registration data from the user device, and perform an action based on the second IMS registration data.