Systems and methods relating to an efficient communication system to, e.g., support Massive Machine Type Communication (M-MTC) devices are disclosed. In some embodiments, a base station in a cellular communications network comprises, during initial attachment of a wireless device, establishing a Data Radio Bearer (DRB) between the base station and the wireless device, updating a context of the wireless device to include information regarding the DRB established between the base station and the wireless device to thereby provide a mapping between the DRB and a cellular network identifier of the wireless device. The method further comprises, during initial attachment of the wireless device, providing, to the wireless device, at least a portion of an Internet Protocol (IP) address assigned to the wireless device and updating the context of the wireless device to include the at least a portion of the IP address of the wireless device.