Method and apparatus for completing a circuit switched service call in an internet protocol network

A non-transitory computer-readable medium storing a plurality of instructions which, when executed by a processor, cause the processor to perform operations for processing a session request in an internet protocol network, the operations comprising:

• receiving the session request from a calling party to a called party, wherein the session request includes a service tag;
• determining a value of the service tag in the session request, wherein the service tag comprises a label that is added to the session request that indicates a type of service for the session request, wherein the value of the service tag represents at least one of:
• a first service or a second service, wherein the first service is different from the second service;
• querying a telephone numbering mapping server for a plurality of naming authority pointer resource records associated with the called party, wherein the telephone numbering mapping server locates one of the plurality of naming authority pointer resource records that the called party is registered to;
• selecting one of the plurality of naming authority pointer resource records in accordance with the service tag, when the plurality of naming authority pointer resource records associated with the called party are returned, wherein telephone Universal Resource identifier (URI) is selected if the value of the service tag selected is the first service, and wherein session initiation protocol Universal Resource Identifier (SIP URI) is selected if the value of the service tag selected is the second service;
• and
• processing the session request using the one of the plurality of naming authority pointer resource records that is selected.

An apparatus for processing a session request in an internet protocol network, the apparatus comprising:

• a processor;
• and
• a computer-readable medium storing a plurality of instructions which, when executed by the processor, cause the processor to perform operations, the operations comprising:
• receiving the session request from a calling party to a called party, wherein the session request includes a service tag;
• determining a value of the service tag in the session request, wherein the service tag comprises a label that is added to the session request that indicates a type of service for the session request, wherein the value of the service tag represents at least one of:
• a first service or a second service, wherein the first service is different from the second service;
• querying a telephone numbering mapping server for a plurality of naming authority pointer resource records associated with the called party, wherein the telephone numbering mapping server locates one of the plurality of naming authority pointer resource records that the called party is registered to;
• selecting one of the plurality of naming authority pointer resource records in accordance with the service tag, when the plurality of naming authority pointer resource records associated with the called party are returned, wherein telephone Universal Resource identifier (URI) is selected if the value of the service tag selected is the first service, and wherein session initiation protocol Universal Resource Identifier (SIP URI) is selected if the value of the service tag selected is the second service;
• and
• processing the session request using the one of the plurality of naming authority pointer resource records that is selected.