In reply to jathimoo:
From your problem statement it seems your Dut is half duplex which is sending packet in one direction at one time. If this is the case then you can capture packet at DUT side and analyise and can take out your useful info from there. And then you can set your configuration database and you can get that info your test case, From there you can use this info for driving you sequence. (using .start method)
NOTE: By this procedure you may need to use uvm_events.
If this is not the case then let me know if i am missing something.