def receive_ack_requesting(self, pkt):
        """Receive ACK in REQUESTING state."""
        logger.debug("C3. Received ACK?, in REQUESTING state.")
        if self.process_received_ack(pkt):
            logger.debug("C3: T. Received ACK, in REQUESTING state, "
                         "raise BOUND.")
            raise self.BOUND()
Receive ACK in REQUESTING state.