Telephone call processing using SIP and/or ENUM

• US 7,277,421 B1
• Filed: 01/16/2002
• Issued: 10/02/2007
• Est. Priority Date: 01/16/2002
• Status: Active Grant

• Current Assignee: Verizon Patent and Licensing Incorporated (Verizon Communications Inc.)
• Original Assignee: Verizon Services Corporation (Verizon Communications Inc.)
• Inventors: Pershan, Paul Barry
• Primary Examiner(s): Chan, Wing
• Assistant Examiner(s): LEE, ANDREW CHUNG CHEUNG
• Application Number:
  US10/050,733
• Time in Patent Office: 2,085 Days
• Field of Search: 370252-257, 370/352, 370/400, 370/522, 370/395.2
• US Class Current: 370/352
• CPC Class Codes: H04L 61/4557 Directories for hybrid networks, e.g. including telephone numbers
• CPC Class Codes: H04L 65/104 in the network
• CPC Class Codes: H04M 2207/12 intelligent networks
• CPC Class Codes: H04M 3/42297 with number portability
• CPC Class Codes: H04M 7/128 Details of addressing, directories or routing tables

Abstract

AIN based methods and apparatus for transitioning telephone numbers and customers from the PSTN to a VOIP network are described. AIN line number portability features are used to allow a few gateway switches that interconnect the PSTN and VOIP networks to service customers whose telephone numbers were originally serviced by several remote PSTN switches. AIN LNP triggers are used to forward PSTN calls, directed to the PSTN switch previously used to service a telephone number, to the gateway switch assigned to route such calls to the IP network. AIN triggers set at the gateway switch insure that the subscriber with the ported telephone number continues to receive AIN services provided before the telephone number was ported to the IP network. Calls from ported telephone numbers to telephones in the PSTN are billed from PSTN switches through the use of AIN functionality and triggers set at the gateway switch.

Claims

1. A method of servicing a telephone call directed to an Internet Protocol telephony device coupled to an Internet Protocol network, the telephone call being placed from a telephone device coupled to a public telephone network by dialing a first telephone number associated with the Internet Protocol telephony device, the method comprising the steps of:

activating a local number portability trigger set at a first telephone switch included in said public telephone network, the local number portability trigger being responsive to calls received by said first telephone switch directed to said first telephone number;

pausing call processing at said first telephone switch in response to activation of said local number portability trigger;

accessing a local number portability database to obtain a number associated with a second telephone switch included in the public telephone network;

activating a second trigger set at the second telephone switch, the second trigger being responsive to calls received by said second telephone switch directed to said first telephone number;

accessing a database maintained in said Internet Protocol network in response to said second trigger to obtain there from information associated with the first telephone number; and

controlling completion of said call by said second telephone switch as a function of the information obtained from said Internet Protocol network database.

2. The method of claim 1,

wherein the obtained information includes call forwarding information;

and

wherein the step of controlling completion of said call includes operating said second telephone switch to route said call using a second telephone number included in the obtained information.

3. The method of claim 1, wherein the obtained information includes call forwarding information.

4. The method of claim 3,

wherein the obtained information includes an Internet Protocol address;

and

wherein the step of controlling completion of said call includes operating said second telephone switch to route said call using the IP address included in the obtained information.

5. The method of claim 4,

wherein the obtained information includes call screening information;

and

wherein the step of controlling completion of said call includes terminating said call without completing it to said first telephone number when said call screening information indicates that the call will not be completed successfully by the Internet Protocol network to the Internet telephony device corresponding to the first telephone number.

6. The method of claim 5, wherein the call screening information includes bandwidth information.

7. The method of claim 5, wherein the call screening information includes language information.

8. The method of claim 5, wherein the call screening information includes calling party telephone number information.

9. The method of claim 1, wherein said second trigger is an advanced intelligent network trigger, the method further comprising the step of:

pausing call processing at said second telephone switch following activation of said second trigger; and

sending a message to a service control point located in said public telephone network, the service control point performing said accessing of the Internet Protocol network database.

10. The method of claim 9, wherein the step of accessing said Internet Protocol network database includes:

using Session Initiation Protocol (SIP) to contact a device in said Internet Protocol network which is responsible for retrieving information from said Internet Protocol network database.

11. The method of claim 10, wherein said second telephone switch is a gateway switch which interconnects said public telephone network with the Internet Protocol network, the method further comprising, for calls completed to said Internet Protocol telephony device:

operating the gateway switch to generate Internet Protocol packets corresponding to said telephone call; and

transmitting said generated Internet Protocol packets to the Internet Protocol network for delivery to said Internet Protocol telephony device.

12. The method of claim 9, wherein the step of accessing said Internet Protocol network database includes:

using ENUM to contact a device in said Internet Protocol network which is responsible for retrieving information from said Internet Protocol network database.

13. The method of claim 12, wherein said device in said Internet Protocol network which is contacted is a domain name server.

14. The method of claim 1, wherein the step of accessing said Internet Protocol network database includes:

using Session Initiation Protocol (SIP) to contact a device in said Internet Protocol network which is responsible for retrieving information from said Internet Protocol network database.

15. The method of claim 1, wherein the step of accessing said Internet Protocol network database includes:

using ENUM to contact a device in said Internet Protocol network which is responsible for retrieving information from said Internet Protocol network database.

16. A method of forwarding a call from a calling party to a called party via an Internet Protocol (IP) network where the called party is associated with a called party telephone number and the calling party is associated with a calling party telephone number, comprising:

receiving at a second service switching point (SSP) a call routing message from a first SSP, the call routing message having a telephone number of the second SSP in a called party field of the call routing message and the called party telephone number in another field of the call routing message;

determining that the called party telephone number is associated with a device connected to the IP network;

forwarding the call to a switching device connected to the second SSP, the switching device also connected to the IP network, including the called party telephone number;

determining a called party IP network address based on the called party telephone number;

converting the call to a plurality of IP packets;

directing the plurality of IP packets to the called party IP address.

17. The method of claim 16, further comprising:

receiving a call request for the call at the first SSP, including receiving the called party telephone number;

determining that a local number portability trigger has been set at the first SSP that is applicable to the calling party telephone number;

transmitting a call processing message to a first SCP;

retrieving a local routing number associated with the called party telephone number, the local routing number comprising the telephone number of the second SSP;

transmitting a call control message to the first SSP, the call control message including the local routing number and the called party telephone number;

routing the call to the second SSP.

18. The method of claim 16, further comprising:

determining that a trigger has been set at the second SSP that is applicable to the called party telephone number;

transmitting a call processing message to a second SCP, the call processing message including the called party telephone number;

determining whether one or more AIN services are associated with the called party telephone number and performing said one or more AIN services;

transmitting a call control message to the second SSP instructing the second SSP to complete the call.

19. The method of claim 18, further comprising:

sending a first SIP message to a device in the IP network and including the called party telephone number, and receiving a second SIP message in response to the first SIP message, the second SIP message including at least one of call routing information, bandwidth information, and screening information.

20. The method of claim 18, further comprising:

sending a first ENUM message to a device in the IP network and including the called party telephone number, and receiving a second ENUM message in response to the first ENUM message, the second ENUM message including at least one of call routing information, bandwidth information, and screening information.

21. A method of forwarding a call from a calling party to a called party via an Internet Protocol (IP) network where the called party is associated with a called party telephone number and the calling party is associated with a calling party telephone number, comprising:

receiving at a device in the IP network a call request associated with the call, the call request including the called party telephone number;

determining routing information for the call based on the called party telephone number, wherein the routing information indicates a gateway to a circuit-switched telephone network;

sending a call routing message to the gateway, the call routing message having the calling party telephone number located in a called party number field of the call routing message, and the called party telephone number located in a another field of the call routing message;

receiving the call routing message at the gateway;

activating a trigger based on the called party number field;

determining that the call originated from the IP network based on the calling party telephone number;

determining a billing location associated with the calling party telephone number and sending a billing instruction to a billing location;

retrieving the called party telephone number from the another field of the call routing message; and

routing the call to the called party telephone number via a switch in the circuit-switched telephone network.