A dual port external wireless modem is disclosed. According to one embodiment, the external wireless modem receives command and control information over a primary serial port, and real-time data over a secondary serial port. The primary serial port is further configured to received packet switched data, such as short message service messages, while the secondary serial port is configured to received circuit switched data. An RF transceiver in the wireless modem modulates data and control received over the respective serial ports, preferably using a GSM protocol stack. According to an embodiment, the circuit switched and packet switched data received at the wireless modem can be simultaneously transmitted by the RF transceiver without interrupting the circuit switched data transfer, thereby avoiding a context switch and a loss of throughput.