A method of determining a telephony network node for routing a call is
disclosed. The method includes receiving a call request at a service
provider node, the call request including a called number to reach a
called party. The method further includes sending a combined telephone
number mapping (ENUM) and local number portability (LNP) query from the
service provider node to a remote ENUM database, the combined ENUM/LNP
query including the called number. The method further includes receiving
a response to the combined ENUM/LNP query at the service provider node.
The response includes one of an internet protocol address that identifies
a node of an internet protocol network, a local routing number (LRN) to
be used to route the call to a uniquely identified switching node of a
circuit-switched network, or a return of the called number to indicate
that the called number can be used to route the call to the called party.