The advanced intelligent network (AIN) to determine routing of voice calls
alternatively between the public switched telephone network (PSTN) and a
data packet network, such as the Internet, in accordance with the quality
of service existing in the data packet network at the times of call
origination. The user's acceptable level of service may be predefined with
a threshold quality level stored in the user's Call Processing Record
(CPR) in the AIN Integrated Services Control Point (ISCP). On a per call
basis, the caller linked to a first public switched network may indicate a
preference to route through the Internet. This indication is recognized by
the AIN system, in response to which the quality of service currently
present on the Internet for completion of the call is measured. If the
result exceeds the stored threshold, the call is setup and routed through
the Internet to the switched network link to the destination party. If the
quality of service on the Internet is not satisfactory, the call is
alternatively routed through the PSTN, which may include an Interexchange
Carrier link. The AIN system automatically controls the alternative
routing of such calls.