systems and methods for providing advanced telephony services to telephone numbers served by telecommunications networks lacking the infrastructure to provide these advanced services directly are described . in an embodiment of the present invention , a service - providing network , which has the capability of providing advanced telephony services to a service subscriber for calls that traverse it , provides advanced telephony services to calls directed to a telephony device on a native transport network . the native transport network is a network that naturally carries a subscriber &# 39 ; s calls but does not have the capabilities required to provide advanced services . in one embodiment , the system switch provisioning and trunking configurations to provide the advanced telephony services .