We got it addressed it looks like. I corrected the ports 9000-9001 to the phone system - though we had tried it both ways.

Per the recommendation of a tech we work with, he suggested making both MMC830 & 831 be Private w/ Public on each, then restarting the MGI card followed by the phone system itself.

This apparently made everything happy. We now have voice both ways from the public side of things. Thanks for viewing.