'Listens for 1 connection on the inbound port, transfers the data and
then returns. This function should be called with tm.apply_async ; and
afterwards you should exec the ftp client on the remote server.'

def _serve(self, data_str):

    server_socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
    server_socket.bind(('', self._inbound_port))
    server_socket.listen(1)
    (client_socket, addr) = server_socket.accept()
    client_socket.send(data_str)
    client_socket.close()
    return True
