A method may include receiving, at a network device, from a calling party location, an input setup message that includes a called party phone number value; determining whether the input setup message includes a voice telephony over asynchronous transfer mode (VToA) designator; generating an output setup message including an alias address associated with a network gateway that is in communication with a public switched telephone network (PSTN) switch through a plurality of trunk lines when it is determined that the input setup message includes a VToA designator, where the alias address is based on the called party phone number value and indicates a desired trunk line of the plurality of trunk lines; and transmitting the output setup message, the output setup message causing the selection of the desired trunk line of the plurality of trunk lines in order to establish communication between the calling party location and the PSTN switch.