3.1.6.9 Order Ack Send Timer Event
When the Order Ack Send Timer (section 3.1.2.7) expires, if the session from which the timer was started is not closed, the protocol MUST send an OrderAck Packet (section 2.2.4) to the sender by raising a Send Transactional Acknowledgment (section 3.1.7.17) event with the following argument:
iMessageClass: MQMSG_CLASS_ORDER_ACK ([MS-MQMQ] section 2.2.18.1.6)
The LastOrderAckSendTime ADM element MUST be set to current system time.