Methods, Systems, and Computer Program Products for Enabling Non-IMS Queries of a Common Telephone Number Mapping System

A communications system, comprising:

• an IP multimedia system (IMS) core that is configured to manage voice over IP communications sessions;
• a non-IMS core that is configured to manage Short Message Service (SMS) and/or Multimedia Message Service (MMS) communications;
• and
• a private telephone number mapping database that is responsive to queries from both the IMS core and the non-IMS core, the private telephone number mapping database containing records that include complete routing information for subscriber terminals within the communications network for both IMS and non-IMS communications.

A computer program product for routing a non-IP multimedia subsystem (IMS) message from a first user terminal that has telecommunications service provided by a first network carrier to a second user terminal that has telecommunications service provided by a second network carrier, the computer program product comprising:

• a computer readable storage medium having computer readable program code embodied in the medium, the computer readable program code comprising:
• computer readable program code configured to search a first telephone number mapping database for an entry for the second user terminal;
• computer readable program code configured to query a second telephone number mapping database to identify an address of a third telephone number mapping database that is operated by the second network carrier in response to not finding any entry for the second user terminal in the first telephone number mapping database;
• computer readable program code configured to use the identified address to query the third telephone number mapping database;
• and
• computer readable program code configured to receive routing information for the non-IMS message from the third telephone number mapping database in response to the query to the third telephone number mapping database.