int
dtls1_get_queue_priority(unsigned short seq, int is_ccs)
	{
	/* The index of the retransmission queue actually is the message sequence number,
	 * since the queue only contains messages of a single handshake. However, the
	 * ChangeCipherSpec has no message sequence number and so using only the sequence
	 * will result in the CCS and Finished having the same index. To prevent this,
	 * the sequence number is multiplied by 2. In case of a CCS 1 is subtracted.
	 * This does not only differ CSS and Finished, it also maintains the order of the
	 * index (important for priority queues) and fits in the unsigned short variable.
	 */	
	return seq * 2 - is_ccs;
	}