in one configuration , the present invention is directed to an enterprise network that includes geographically dislocated first and second network regions 202 and 206 communicating with one another through first and second networks 252 and 248 and respectively comprising first and second gateways 220 and 224 and first and second groupings of trunks . a common electronic address is associated with the second grouping of trunks . a media server 200 is positioned in the first network region 202 that includes an inter - gateway routing agent 260 . the first network region transmits , as part of the establishment of a real - time or near real - time communication between first and second subscribers respectively in the first and second network regions , the common address to the second gateway 224 . after the outgoing communication is answered by the second gateway 224 , the first network region transmits in band to the second gateway 224 a user identifier associated with the second subscriber and / or a phantom user . the user identifier is used to establish the communication with the second subscriber .