Integration of VoIP address discovery with PBXs

• US 8,228,903 B2
• Filed: 06/30/2009
• Issued: 07/24/2012
• Est. Priority Date: 07/20/2007
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Rosenberg, Jonathan David, Jennings, Cullen F., Mehmood, Hakim N., Hendrickson, Mark L., Alexander, John D., Restrick, John K. Jr.
• Primary Examiner(s): Scheibel, Robert
• Assistant Examiner(s): Mais, Mark A
• Application Number:
  US12/495,639
• Publication Number:
  US 20100002687A1
• Time in Patent Office: 1,120 Days
• Field of Search: 370351-354, 370/356, 370/386, 370/389, 370/392, 370/395.31, 370/395.52, 370/400, 370/401, 370/402, 370/494
• US Class Current: 370/353
• CPC Class Codes: H04L 61/4557 Directories for hybrid networks, e.g. including telephone numbers
• CPC Class Codes: H04L 65/1036 at the edge
• CPC Class Codes: H04L 65/1069 Session establishment or de-establishment
• CPC Class Codes: H04M 2203/551 Call history
• CPC Class Codes: H04M 3/5125 with remote located operators
• CPC Class Codes: H04M 3/5232 Call distribution algorithms
• 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: H04M 7/006 Networks other than PSTN/ISDN providing telephone service, e.g. Voice over Internet Protocol (VoIP) , including next generation networks with a packet-switched transport layer H04L65/00 takes precedence; aspects not specific to the type of network H04M3/00; special services in those networks H04M3/42
• CPC Class Codes: H04M 7/0063 where the network is a peer-to-peer network

Abstract

A system for verifying VoIP call routing information. The system may include an apparatus integrated with a private branch exchange (PBX). The apparatus may store at least one call attribute of a public switched telephone network (PSTN) call initiated to a destination telephone number. The apparatus may verify a destination Voice-over-Internet-Protocol (VoIP) call agent for the destination telephone number based on demonstrated knowledge of the PSTN call. The apparatus may route a new call either over a VoIP network to the destination VoIP call agent or over a circuit switched network based on whether the destination VoIP call agent is verified for the destination telephone number.

Claims

1. An apparatus comprising:

a memory; and

a processor in communication with the memory, the memory including computer code executable with the processor, wherein the computer code is configured to;

store at least one call attribute of at least one public switched telephone network (PSTN) call initiated over the PSTN by a private branch exchange (PBX) to a destination telephone number, the at least one call attribute demonstrating knowledge of the at least one PSTN call;

verify a destination Voice-over-Internet-Protocol (VoIP) call agent is reachable over the PSTN at the destination telephone number based on demonstrated knowledge by the destination VoIP call agent of the at least one call attribute of the at least one PSTN call initiated over the PSTN to the destination telephone number; and

route a call to the destination telephone number either over a VoIP network to the destination VoIP call agent if the destination VoIP call agent is verified as reachable over the PSTN at the destination telephone number, or over a circuit switched network from the PBX if the destination VoIP call agent is not verified as reachable over the PSTN at the destination telephone number.

2. The apparatus of claim 1, wherein the computer code configured to route the call is further configured to:

receive a first call initiation message for the call from the PBX; and

transmit a second call initiation message for the call either to the destination VoIP call agent over the VoIP network if the destination VoIP call agent is verified as reachable over the PSTN at the destination telephone number or to the PBX if the destination VoIP call agent is not verified as reachable over the PSTN at the destination telephone number.

3. The apparatus of claim 1, wherein the computer code configured to route the call is further configured to:

receive a first call initiation message for the call from the PBX; and

transmit either a second call initiation message for the call to the destination VoIP call agent over the VoIP network if the destination VoIP call agent is verified as reachable over the PSTN at the destination telephone number or a call rejection message to the PBX if the destination VoIP call agent is not verified as reachable over the PSTN at the destination telephone number.

4. The apparatus of claim 1, wherein the computer code is further configured to retrieve the at least one call attribute of the at least one PSTN call from call detail records.

5. The apparatus of claim 1, wherein the computer code is further configured to receive the at least one call attribute of the at least one PSTN call via a computer telephony interface (CTI) module.

6. The apparatus of claim 1, wherein the computer code configured to route the call is further configured to control via a computer telephony interface (CTI) module whether the call is routed from the PBX either to the apparatus if the destination VoIP call agent is verified as reachable over the PSTN at the destination telephone number or over the PSTN if the destination VoIP call agent is not verified as reachable over the PSTN at the destination telephone number.

7. The apparatus of claim 1, wherein the at least one call attribute includes a start time of a respective one of the at least one PSTN call and a duration of the respective one of the at least one PSTN call.

21. The apparatus of claim 1, wherein the computer code configured to route the call either over the VoIP network or over the circuit switched network is further configured to:

communicate with the PBX over a programmatic interface provided by the PBX; and

instruct the PBX through the programmatic interface to route calls to the destination telephone number over the VoIP network if the destination VoIP call agent is verified as reachable over the PSTN at the destination telephone number or over the circuit switched network if the destination VoIP call agent is not verified as reachable over the PSTN at the destination telephone number.

22. The apparatus of claim 21, wherein the programmatic interface is a computer telephony interface (CTI).

8. Logic encoded in one or more tangible non-transitory media for execution with a processor and when executed operable to:

store at least one call attribute of a public switched telephone network (PSTN) call initiated over the PSTN by a private branch exchange (PBX) to a destination telephone number, the at least one call attribute demonstrating knowledge of the PSTN call;

verify a destination Voice-over-Internet-Protocol (VoIP) call agent is reachable over the PSTN at the destination telephone number based on demonstrated knowledge by the destination VoIP call agent of the at least one call attribute of the PSTN call initiated over the PSTN to the destination telephone number; and

route a call to the destination telephone number either over a VoIP network to the destination VoIP call agent if the destination VoIP call agent is verified as reachable over the PSTN at the destination telephone number, or over a circuit switched network from the PBX if the destination VoIP call agent is not verified as reachable over the PSTN at the destination telephone number.

9. The tangible media of claim 8, wherein the logic to route the call, when executed, is further operable to:

receive a first call initiation message for the call from the PBX; and

transmit a second call initiation message for the call either to the destination VoIP call agent over the VoIP network if the destination VoIP call agent is verified as reachable over the PSTN at the destination telephone number or to the PBX if the destination VoIP call agent is not verified as reachable over the PSTN at the destination telephone number.

10. The tangible media of claim 8, wherein the logic to route the call, when executed, is further operable to:

receive a first call initiation message for the call from the PBX; and

transmit either a second call initiation message for the call to the destination VoIP call agent over the VoIP network if the destination VoIP call agent is verified as reachable over the PSTN at the destination telephone number or a call rejection message to the PBX if the destination VoIP call agent is not verified as reachable over the PSTN at the destination telephone number.

11. The tangible media of claim 8, wherein the logic when executed is further operable to receive the at least one call attribute of the PSTN call from a computer telephony interface (CTI) module in communication with the PBX.

12. The tangible media of claim 8, wherein the logic to route the call, when executed, is further operable to control, via a computer telephony interface (CTI) module, where the PBX is to route the call based on whether the destination VoIP call agent is verified as reachable over the PSTN at the destination telephone number.

13. The tangible media of claim 8, wherein the logic to verify the destination VoIP call agent, when executed, is further operable to receive proof of knowledge of the PSTN call as part of an encrypted key exchange protocol, wherein a shared secret in the encrypted key exchange protocol is based on the at least one call attribute of the PSTN call.

14. A method comprising:

receiving from a private branch exchange (PBX) at least one call attribute of a public switched telephone network (PSTN) call initiated over the PSTN by the PBX to a destination telephone number, the at least one call attribute demonstrating knowledge of the PSTN call;

verifying a destination Voice-over-Internet-Protocol (VoIP) call agent is reachable over the PSTN at the destination telephone number based on demonstrated knowledge by the destination VoIP call agent of the at least one call attribute of the PSTN call; and

routing a new call received from the PBX either over a VoIP network to the destination VoIP call agent if the destination VoIP call agent is verified as reachable over the PSTN at the destination telephone number, or over a circuit switched network if the destination VoIP call agent is not verified as reachable over the PSTN at the destination telephone number.

15. The method of claim 14, wherein routing the call further comprises:

receiving a first call initiation message for the new call from the PBX; and

transmitting a second call initiation message for the call either to the destination VoIP call agent over the VoIP network if the destination VoIP call agent is verified as reachable over the PSTN at the destination telephone number or to the PBX if the destination VoIP call agent is not verified as reachable over the PSTN at the destination telephone number.

16. The method of claim 14, wherein routing the call further comprises:

receiving a first call initiation message for the new call from the PBX; and

transmitting either a second call initiation message for the call to the destination VoIP call agent over the VoIP network if the destination VoIP call agent is verified as reachable over the PSTN at the destination telephone number or a call rejection message to the PBX if the destination VoIP call agent is not verified as reachable over the PSTN at the destination telephone number.

17. The method of claim 14, wherein receiving the at least one call attribute from the PBX further comprises receiving the at least one call attribute of the PSTN call from call detail records.

18. The method of claim 14, wherein receiving the at least one call attribute from the PBX further comprises receiving the at least one call attribute of the PSTN call from a computer telephony interface (CTI) module in communication with the PBX.

19. The method of claim 14, wherein routing the call further comprises:

receiving a notification of initiation of the call to the destination telephone number from a computer telephony interface (CTI) module, the CTI module in communication with the PBX;

transmitting an invalid telephone number associated with the destination telephone number to the CTI module in response to receipt of the notification of initiation of the call and in response to a match of the destination telephone number with an entry in a cache of validated VoIP call routing information, the entry in the cache of validated VoIP call routing information indicating that the destination VoIP call agent is verified as reachable over the PSTN at the destination telephone number;

receiving a first call initiation message to the invalid telephone number; and

transmitting a second call initiation message for the destination telephone number to the destination VoIP call agent over the VoIP network in response to receipt of the first call initiation message to the invalid telephone number.

20. The method of claim 14, wherein verifying the destination VoIP call agent further comprises delaying a random amount of time after receiving the at least one call attribute of the PSTN call before transmitting a request for the destination VoIP call agent to demonstrate knowledge of the PSTN call.