A vehicle includes a telematics control unit and a processor that may receive a wake-up message, via the telematics control unit, from a service delivery network (SDN), requesting a response from the vehicle. The vehicle may determine, based on a rejected data call attempted as the response, that a current network cell is congested. The vehicle may additionally notify the SDN of the congestion, via a predetermined communication format indicated as being available when a cell is congested. Also, the vehicle may use the predetermined communication format for communication with the SDN until the current network cell congestion is relieved or that the vehicle has traveled out of range of the current network cell.