def sendAckPacket(self, ipp, mode, flags, ack_key):
        packet = ['AK']
        packet.append(self.main.osm.me.ipp)
        packet.append(struct.pack("!BB", mode, flags))
        packet.append(ack_key)

        ad = Ad().setRawIPPort(ipp)
        self.main.ph.sendPacket(''.join(packet), ad.getAddrTuple())