System and method for routing voice over IP calls

• US 20030086411A1
• Filed: 11/02/2001
• Published: 05/08/2003
• Est. Priority Date: 11/02/2001
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Vassilovski, Dan
• Granted Patent: US 6,813,264 B2
• Time in Patent Office: Days
• US Class Current: 370/352
• CPC Class Codes: H04L 12/2898 Subscriber equipments DSL modems H04M11/062; cable modems H04L12/2801
• CPC Class Codes: H04L 45/00 Routing or path finding of packets in data switching networks routing or path finding in wireless networks H04W40/00
• CPC Class Codes: H04L 45/22 Alternate routing
• CPC Class Codes: H04L 63/0428 wherein the data content is protected, e.g. by encrypting or encapsulating the payload
• CPC Class Codes: H04L 65/1069 Session establishment or de-establishment
• CPC Class Codes: H04L 65/1101 Session protocols
• CPC Class Codes: H04L 65/1104 Session initiation protocol [SIP]
• CPC Class Codes: H04M 2207/18 wireless networks
• CPC Class Codes: H04M 7/0057 Services where the data services network provides a telephone service in addition or as an alternative, e.g. for backup purposes, to the telephone service provided by the telephone services network
• CPC Class Codes: H04Q 3/0025 Provisions for signalling
• CPC Class Codes: H04Q 3/0045 involving hybrid, i.e. a mixture of public and private, or multi-vendor systems
• CPC Class Codes: H04W 12/033 of the user plane, e.g. user's traffic
• CPC Class Codes: H04W 76/10 Connection setup

Abstract

An SIP server in an IP-based infrastructure supporting wireless telephones determines whether, based on the destination address in a call request, the call is an intrasystem call or an intersystem call. For intrasystem calls the SIP server routes VOIP packets directly between the originating and destination devices. For intersystem calls, however, and in particular encrypted calls, instead of routing the VOIP packets through the public Internet, the SIP server instantiates a circuit-switched call using a local modem bank connected to the PSTN. In this way, quality of service assurance is obtained and latency reduced.

Claims

1. A voice over Internet (VOIP) system, comprising:

at least one IP-based infrastructure component communicating with at least one wireless originating device;

at least one SIP server communicating with the infrastructure component; and

at least one modem bank associated with the SIP server and connected to a PSTN, the SIP server selectively using the modem bank to instantiate a circuit-switched call from the originating device to a destination device.

2. The system of claim 1, wherein the SIP server initiates the instantiation of circuit-switched calls only for encrypted intersystem calls.

3. The system of claim 1, wherein the SIP server initiates the instantiation of a circuit-switched call to the destination device when an address or portion thereof of the destination device is not in the same system as the originating device.

4. The system of claim 1, wherein the SIP server does not instantiate a circuit-switched call for an intrasystem call.

5. The system of claim 1, wherein the SIP server does not instantiate a circuit-switched call to a destination device having an address or portion thereof registered with the SIP server.

6. The system of claim 3, wherein the destination device has an IP address of the form “

sip;

//[e-mail]”

, and the circuit switched call is instantiated using the DN portion of the IP address.

7. The system of claim 6, wherein the SIP server maps the DN to the modem bank and completes the call through the PSTN.

8. The system of claim 1, wherein at least the originating device uses CDMA principles.

9. A method for VOIP, comprising:

receiving from an originating wireless device in a first service system a call request for a destination device having an IP address;

determining whether the destination device is in the first service system;

if the destination device is in the first service system, establishing VOIP communication between the originating device and destination device within the first service system without using the public Internet;

otherwise;

establishing a circuit-switched VOIP call between the destination device and originating device using the PSTN.

10. The method of claim 9, wherein the act of establishing is undertaken by instantiating a circuit-switched call through a modem bank associated with the first service system only for encrypted calls.

11. The method of claim 10, wherein the determining act is undertaken based on the IP address of the destination device.

12. The method of claim 10, comprising mapping at least a DN of the destination device to the modem bank and completing the call through the PSTN.

13. The method of claim 9, wherein at least the originating device uses CDMA.

14. A computer program device, comprising:

means for receiving a call request at an SIP server, the call request being generated by a wireless communication originating device and indicating a destination device;

means for determining whether the destination device is registered with the SIP server;

means for transmitting IP packets between the destination device and originating device without using the public Internet when the destination device is registered with the SIP server; and

means for transmitting IP packets between the destination device and originating device using an instantiated circuit-switched connection when the destination device is not registered with the SIP server.

15. The device of claim 14, wherein the means for transmitting IP packets between the destination device and originating device using an instantiated circuit-switched connection includes means for instantiating a circuit-switched call through a modem bank associated with the SIP server only for encrypted calls.

16. The device of claim 15, wherein the means for transmitting IP packets between the destination device and originating device using an instantiated circuit-switched connection includes means for mapping at least a DN of the destination device to the modem bank and completing the call through a PSTN.

17. A method for executing an encrypted VOIP call between an originating device and a destination device, comprising:

requesting an encrypted call to the destination device; and

establishing one of two communication pathways between the devices based on the request, neither pathway traversing publicly-accessible portions of the Internet.

18. The method of claim 17, wherein an intrasystem pathway is established within an IP infrastructure, no part of the intrasystem pathway traversing the public Internet.

19. The method of claim 18, wherein an intersystem pathway is established including the IP infrastructure, at least one modem bank associated therewith, and the PSTN connected to the modem bank, whereby no part of the intersystem pathway traverses the public Internet.