TCP Algorithm (NewReno)

NewReno = AIMD, slow start, fast recovery, triple acknowledgement

if (seqno > _last_acked) {		/* new data arrived */
	if (! _in_fast_recovery) {
		_last_acked = seqno;
		_dupacks = 0;
		inflate_window();	/* AI part of AIMD */
		send_packets(now());
		_last_sent_time = now();
	} else if (seqno < _recover) {
		uint32 new_data = seqno - _last_acked;
		_last_acked = seqno;
		if (new_data < _cwnd) {
			_cwnd -= new_data;
		} else {
			_cwnd = 0;
		};
		_cwnd += _mss;
		retransmit_packet(now());
		send_packets(now());
	} else {
		uint32 flightsize = _highest_sent - seqno;
		_cwnd = min(_ssthresh, flightsize + _mss);
		_last_acked = seqno;
		_dupacks = 0;
		_in_fast_recovery = FALSE;
		send_packets(now());
	};
} else if (_in_fast_recovery) {
	_cwnd += _mss;			/* AI part of AIMD */
	send_packets(now());
} else {				/* old data duplicated */
	_dupacks++;
	if (_dupacks != 3) {
		send_packets(now());
	} else {
		_ssthresh = max(_cwnd/2, (uint32)(2 * _mss));
					/* MD part of AIMD */
		retransmit_packet(now());
		_cwnd = _ssthresh + 3*_mss;
		_in_fast_recovery = TRUE;
		_recover = _highest_sent;
	};
}