Abstract: Programmatically reversing numerical line identity presented at a communications services gateway into named IP Telephony users with “prior association”, delivers dynamic “reverse address resolution” switching connections from ground to cloud, permitting any conventional telephone to dial and connect to any associated IP Telephony endpoint in the world, without changes to the conventional telephone. Reversing line identity into associated named users bridges both the addressability and economic divide between mass conventional “paying” (mobile and fixed) and “free”. IP Telephony networks.