How does OOO handled in all the cases?

In reply to dave_59:

In reply to uvmsd:
I think you may be confusing two different things. The transaction_id is used to send a response back to the sequence that sent the sequence_item. It doesn’t matter if the responses are in-order or out-of-order. If the response are out of order, then you’ll have to use the same technique you used in the scoreboard to match the responses from the driver, like the unique field value.

ok, thanks Dave.
I was bit confused since when I searched for out of order handling, out of order driver was also listed.
BTW, in case of out of order responses, the unique field value is from the transaction field ?