Dialed number service routing in a telephone network by reference to a database

In accordance with an improved call routing methodology, a call is routed within a communication network by reference to one or more databases. In response to receiving a local number portability request at a service control point (SCP), the SCP accesses one or more databases to determine whether or not to apply custom call routing to a call directed to a called telecommunications number. In response to determining to apply custom call routing to the call, the SCP performs at least a second access to the one or more databases to obtain a local routing number (LRN) associated within the one or more databases with a calling telecommunications number associated with the call. The SCP thereafter provides the LRN to a service switch point in the communication network so that the call is routed to a called station associated with the called telecommunications number.