def sendACK(rxp_socket): print "Sending ACK!" header = RxPPacketHeader() header.src_port = rxp_socket.source_address[1] header.dst_port = rxp_socket.destination_address[1] header.ack_flag = 1 header.ack_number = rxp_socket.ack_number packet = RxPPacket(header) rxp_socket.sendPacket(packet)