Method and apparatus for tracking data packets in a packet data communication system

A packet data communication system (100) employs a method and apparatus for tracking data packets in the packet data communication system. A sending communication device (e.g., 101) transmits a data packet (130) to a receiving communication device (e.g., 105), wherein the data packet includes a respective packet sequence number (131). Responsive to the transmission, the sending device increases a transmit tracking number (V(S)) that is used to indicate the packet sequence number of the data packet that is next in sequence to be transmitted. Upon receiving the data packet, the receiving device transmits an acknowledgment data packet (140) to the sending device, wherein the acknowledgment data packet includes a receive tracking number (139). The receive tracking number indicates the packet sequence number of the data packet that the receiving device expects to receive next. Upon receiving the acknowledgment data packet, the sending device determines whether a communication error occurred based on the receive tracking number and the transmit tracking number.