the process of event "AF_DATA_CONFIRM_CMD"

When we set the option parameter of function AF_DataRequest() to AF_ACK_REQUEST, the AF_DATA_CONFIRM_CMD enent indicates whether the data have been received successfully by the destined end.  If the status dosen't equal to ZSuccess, that indicates the destined end hasn't received the data after APSC_MAX_FRAME_RETRIES retransmission(is this right?). When this happens , I wan't to retransmit that data. But how can I get that data? Is the lost data placed into a buffer? The next code is founded on the web,but I don't find the answer what to do if ( sentStatus != ZSuccess ). 

case AF_DATA_CONFIRM_CMD:    
          // This message is received as a confirmation of a data packet sent.
          // The status is of ZStatus_t type [defined in ZComDef.h]
          // The message fields are defined in AF.h
          afDataConfirm = (afDataConfirm_t *)MSGpkt;
          sentEP = afDataConfirm->endpoint;
          sentStatus = afDataConfirm->hdr.status;
          sentTransID = afDataConfirm->transID;
          (void)sentEP;
          (void)sentTransID;

          // Action taken when confirmation is received.
          if ( sentStatus != ZSuccess )
          {
            /
          }
          break;
     
        default:
          break;