Methods, systems, and computer program products for using a location routing number based query and response mechanism to route calls to IP multimedia subsystem (IMS) subscribers

• US 8,213,440 B2
• Filed: 03/30/2007
• Issued: 07/03/2012
• Est. Priority Date: 02/21/2007
• Status: Active Grant

• Current Assignee: Tekelec Global, Inc. (Oracle Corporation)
• Original Assignee: Tekelec Global, Inc. (Oracle Corporation)
• Inventors: Bantukul, Apirux, Ravishankar, Venkataramaiah, Marsico, Peter J.
• Primary Examiner(s): Lee, Jay Y
• Application Number:
  US11/731,772
• Publication Number:
  US 20080198862A1
• Time in Patent Office: 1,922 Days
• Field of Search: None
• US Class Current: 370/401
• CPC Class Codes: H04L 61/5084 Providing for device mobility network addressing or numbering for mobility support in wireless networks H04W8/26; mobile IP H04W80/04
• CPC Class Codes: H04L 65/1016 IP multimedia subsystem [IMS]
• CPC Class Codes: H04L 65/104 in the network
• CPC Class Codes: H04L 65/1069 Session establishment or de-establishment
• CPC Class Codes: H04M 3/42297 with number portability
• CPC Class Codes: H04M 7/128 Details of addressing, directories or routing tables
• CPC Class Codes: H04Q 2213/13097 Numbering, addressing
• CPC Class Codes: H04Q 2213/13102 Common translator
• CPC Class Codes: H04Q 2213/13141 Hunting for free outlet, circuit or channel
• CPC Class Codes: H04Q 2213/13248 Multimedia
• CPC Class Codes: H04Q 2213/13389 LAN, internet
• CPC Class Codes: H04Q 3/005 Personal communication services, e.g. provisions for portability of subscriber numbers

Abstract

Methods, systems, and computer program products for using an LRN based query and response mechanism (e.g., a switching office number portability processing system) to route calls to IP multimedia subsystem (IMS) subscribers are disclosed. According to one method, an LRN based response message including a communications service subscriber identifier is received. An IMS gateway LRN associated with the communications service subscriber identifier may be determined. The IMS gateway LRN associated with the communications service subscriber identifier may be inserted into the LRN based response message and routing the message.

Claims

1. A method for routing a call, the method comprising:

at a network routing element separate from a number portability database and a switching office that originates a number portability query;

(a) intercepting a number portability response message that includes a first location routing number (LRN) and a communications service subscriber identifier, the number portability response being generated by the number portability database in response to the number portability query and being destined for the switching office;

(b) in response to intercepting the number portability response message, querying a network offload data structure located within the network routing element using the communications service subscriber identifier to obtain an Internet protocol multimedia subsystem (IMS) gateway LRN associated with the communications service subscriber identifier;

(c) inserting the Internet Protocol multimedia subsystem (IMS) gateway LRN associated with the communications service subscriber identifier into the number portability response message if an entry in the network offload data structure matches the communications service subscriber identifier, wherein inserting the IMS gateway LRN includes replacing the first LRN in the number portability response message with the IMS gateway LRN; and

(d) routing the number portability response message to the switching office.

2. The method of claim 1, wherein querying includes searching a database for an entry including the communications service subscriber identifier, wherein the entry includes the IMS gateway LRN.

3. The method of claim 1, wherein querying includes:

(a) determining whether an entry including the communications service subscriber identifier is located in a first database comprising entries including a plurality of communications service subscriber identifiers and a plurality of associated IMS gateway LRNs, wherein the first database includes the communications service subscriber identifier exceptions to ranges of communications service subscriber identifiers in a second database; and

(b) in response to determining that an entry including the communications service subscriber identifier is not located in the first database, searching the second database for an entry including a range of communications service subscriber identifiers with the communications service subscriber identifier, wherein the entry of the second database including the range of communications service subscriber identifiers with the communications service subscriber identifier includes the IMS gateway LRN.

4. A method for routing a call, the method comprising:

(a) receiving, at a network element and from a switching office, a location routing number (LRN) based query message destined for a local number portability database separate from the network routing element and including a communications service subscriber identifier;

(b) querying, at the network routing element, a network offload data structure located within the network routing element using the communications service subscriber identifier;

(c) acquiring, at the network routing element and from the network offload data structure, an Internet Protocol multimedia subsystem (IMS) gateway LRN associated with the communications service subscriber identifier if an entry in the network offload data structure matches the communications service subscriber identifier;

(d) generating, at the network routing element, an LRN based response message associated with the LRN based query message, wherein the LRN based response message includes the IMS gateway LRN; and

(e) routing the LRN based response message from the network routing element to the switching office and thereby shielding the local number portability database from unnecessary query message traffic.

5. The method of claim 4, wherein the LRN based query message comprises a number portability query message and the LRN based response message comprises a number portability response message.

6. The method of claim 5, wherein querying includes:

(a) determining whether an entry including the communications service subscriber identifier is located in a first database comprising entries including a plurality of communications service subscriber identifiers and a plurality of associated IMS gateway LRNs, wherein the first database includes the communications service subscriber identifier exceptions to ranges of communications service subscriber identifiers in a second database; and

(b) in response to determining that an entry including the communications service subscriber identifier is not located in the first database, searching the second database for an entry including a range of communications service subscriber identifiers with the communications service subscriber identifier, wherein the entry of the second database including the range of communications service subscriber identifiers with the communications service subscriber identifier includes the IMS gateway LRN.

7. The method of claim 5, wherein routing the number portability response message includes routing the number portability response message to an originator of the number portability query message associated with the number portability response message.

8. The method of claim 5, wherein receiving the number portability query message includes intercepting the number portability query message at a network routing node located between a query originating signaling point and a number portability database.

9. The method of claim 5, further comprising routing the number portability query message to a number portability system if the entry in the network offload data structure does not match the communications service subscriber identifier.

10. The method of claim 4, wherein the LRN based query message comprises a send routing information (SRI) query message and the LRN based response message comprises an SRI acknowledgement response message.

11. The method of claim 4, wherein querying includes searching a database for an entry including the communications service subscriber identifier, wherein the entry includes the IMS gateway LRN.

12. A system for routing a call to a subscriber via an Internet Protocol multimedia subsystem (IMS) gateway, the system comprising:

at a network routing element separate from a number portability database and a switching office that originates a number portability query;

(a) a communications module configured to intercept a number portability response message including a communications service subscriber identifier, the number portability response being generated by the number portability database in response to the number portability query and being destined for the switching office; and

(b) an IMS offload function configured to, in response to intercepting the number portability response message, determine an IMS gateway location routing number (LRN) associated with the communications service subscriber identifier, configured to the IMS gateway LRN associated with the communications service subscriber identifier into the number portability response message, and configured to route the number portability response message to the switching office, and wherein the IMS offload function is configured to replace an LRN in the number portability response message with the IMS gateway LRN.

13. The system of claim 12, wherein the IMS offload function is configured to search a database for an entry including the communications service subscriber identifier and wherein the entry includes the IMS gateway LRN.

14. The system of claim 12, wherein the IMS offload function is configured to:

(i) determine whether an entry including the communications service subscriber identifier is located in a first database comprising entries including a plurality of communications service subscriber identifiers and a plurality of associated IMS gateway LRNs, wherein the first database includes communications service subscriber identifier exceptions to ranges of communications service subscriber identifiers in a second database; and

(ii) search the second database, in response to determining that an entry including the communications service subscriber identifier is not located in the first database, for an entry including a range of communications service subscriber identifiers with the communications service subscriber identifier, wherein entry of the second database including the range of communications service subscriber identifiers with the communications service subscriber identifier includes the IMS gateway LRN.

15. A system for routing a call to a subscriber via an Internet Protocol multimedia subsystem (IMS) gateway, the system comprising:

a network routing element including;

(a) a communications module configured to receive, from a switching office, a location routing number (LRN) based query message destined for a local number portability database separate from the network routing element and including a communications service subscriber identifier; and

(b) an IMS offload function configured to;

(i) determine an IMS gateway LRN associated with the communications service subscriber identifier by accessing an IMS offload data structure within the network routing element;

(ii) generate an LRN based response message associated with the LRN based query message and including the IMS gateway LRN in response to determining the IMS gateway LRN; and

(iii) route the LRN based response from the network routing element to the switching office and thereby shielding the local number portability database from unnecessary query message traffic.

16. The system of claim 15, wherein the LRN based query message comprises a number portability query message and the LRN based response message comprises a number portability response message.

17. The system of claim 16, wherein the number portability response message is routed to an originator of the number portability query message associated with the number portability response message.

18. The system of claim 16, wherein the communications module is adapted to intercept the number portability query message at a routing node located between a query originating signaling point and a number portability database.

19. The system of claim 16, wherein the IMS offload function is further adapted to:

(a) buffer the communications service subscriber identifier and requisite transaction identification information that permits a matching of the number portability query message with the associated number portability response message; and

(b) utilize the buffered communications service identifier to search the local number portability database after the associated number portability response message is received.

20. The system of claim 15, wherein the LRN based query message comprises a send routing information (SRI) query message and the LRN based response message comprises an SRI acknowledgement response message.

21. The system of claim 15, wherein the IMS offload function is configured to search a database for an entry including the communications service subscriber identifier and wherein the entry includes the IMS gateway LRN.

22. The system of claim 15, wherein the IMS offload function is configured for:

(a) determining whether an entry including the communications service subscriber identifier is located in a first database comprising entries including a plurality of communications service subscriber identifiers and a plurality of associated IMS gateway LRNs, wherein the first database includes communications service subscriber identifier exceptions to ranges of communications service subscriber identifiers in a second database; and

(b) in response to determining that an entry including the communications service subscriber identifier is not located in the first database, searching the second database for an entry including a range of communications service subscriber identifiers with the communications service subscriber identifier, wherein the entry of the second database including the range of communications service subscriber identifiers with the communications service subscriber identifier includes the IMS gateway LRN.

23. A non-transitory computer readable medium having stored thereon computer executable instructions that when executed by a processor of a computer controls the computer to perform steps comprising:

at a network routing element separate from a number portability database and a switching office that originates a number portability query;

(a) intercepting a number portability response message that includes a first location routing number (LRN) associated with a first network node and a communications service subscriber identifier, the number portability response message being generated by the number portability database in response to the number portability query and being destined for the switching office;

(b) in response to intercepting the number portability response message, querying a network offload data structure within the network routing element using the communications service subscriber identifier to obtain an Internet protocol multimedia subsystem (IMS) gateway LRN associated with the communications service subscriber identifier;

(c) inserting the IMS gateway LRN associated with the communications service subscriber identifier into the number portability response message if an entry in the network offload data structure matches the communications service subscriber identifier, wherein inserting the IMS gateway LRN includes replacing the first LRN in the number portability response message with the IMS gateway LRN; and

(d) routing the number portability response message to the switching office.

24. A non-transitory computer readable medium having stored thereon computer executable instructions that when executed by a processor of a computer controls the computer to perform steps comprising:

at a network routing element;

(a) receiving, at the network routing element and from a switching office, a location routing number (LRN) based query message destined for a local number portability database separate from the network routing element and including a communications service subscriber identifier;

(b) querying, at the network routing element, a network offload data structure within the network routing element using the communications service subscriber identifier;

(c) acquiring, at the network element and from the network offload data structure, an Internet Protocol multimedia subsystem (IMS) gateway LRN associated with the communications service subscriber identifier if an entry in the network offload data structure matches the communications service subscriber identifier;

(d) generating, at the network routing element, an LRN based response message associated with the LRN based query message, wherein the LRN based response message includes the IMS gateway LRN; and

(e) routing the LRN based response message from the network routing element to the switching office and thereby shielding the local number portability database from unnecessary query message traffic.

25. The non-transitory computer readable medium of claim 24, wherein the LRN based query message comprises a number portability query message and the LRN based response message comprises a number portability response message.

26. The non-transitory computer readable medium of claim 24, wherein the LRN based query message comprises a send routing information (SRI) query message and the LRN based response message comprises an SRI acknowledgement response message.