High availability VoIP subsystem

• US 20040032862A1
• Filed: 07/31/2003
• Published: 02/19/2004
• Est. Priority Date: 08/16/2002
• Status: Active Grant

• Current Assignee: Intervoice Incorporated
• Original Assignee: Nuasis Corp. (Concentrix CVG Customer Management Group, Inc.)
• Inventors: Broughton, Justin, Schoeneberger, Carl, Dimitroff, Michael P.
• Granted Patent: US 7,012,888 B2
• Time in Patent Office: Days
• US Class Current: 370/352
• CPC Class Codes: H04L 41/065 involving logical or physical relationship, e.g. grouping and hierarchies
• CPC Class Codes: H04L 41/5003 Managing SLA; Interaction between SLA and QoS
• CPC Class Codes: H04L 41/5064 Customer relationship management
• CPC Class Codes: H04L 51/00 User-to-user messaging in packet-switching networks, transmitted according to store-and-forward or real-time protocols, e.g. e-mail
• CPC Class Codes: H04L 51/04 Real-time or near real-time messaging, e.g. instant messaging [IM]
• CPC Class Codes: H04L 51/222 using geographical location information, e.g. messages transmitted or received in proximity of a certain spot or area
• CPC Class Codes: H04L 51/226 Delivery according to priorities
• CPC Class Codes: H04L 67/10 in which an application is distributed across nodes in the network software deployment G06F8/60; multiprogramming arrangements G06F9/46
• CPC Class Codes: H04M 2203/404 Collaboration among agents
• CPC Class Codes: H04M 2207/203 composed of PSTN and data network, e.g. the Internet
• CPC Class Codes: H04M 3/523 with call distribution or queueing
• CPC Class Codes: H04M 3/5233 Operator skill based call distribution
• CPC Class Codes: H04M 3/5235 Dependent on call type or called number [DNIS]
• 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

Abstract

A high availability VoIP system interfacing with a PSTN or other TDM network to provide higher availability and better failure recovery wherein the high availability VoIP system includes a plurality of gateways coupled to at least one hub and a proxy table and a call restoration table configured in each of the plurality gateways. Further, the present invention is a method of providing a high availability VoIP system wherein the method includes configuring a plurality of gateways between a PSTN and at least one hub of the system, implementing a proxy table and a call restoration table in each of the plurality of gateways, wherein when a call is received by a gateway in the plurality of gateways from the PSTN, the call is divided into a session initiation protocol (SIP) portion and a real time protocol (RTP) portion, and further wherein the SIP portion is sent to a proxy server and the RTP portion is sent to a media server, both being located in the at least one hub and further routed to an endpoint such as a SIP controlled softphone. A further method of the present invention includes routing SIP voice calls through the plurality of gateways using a proxy server priority table.

Claims

1. A high availability voice over internet protocol system coupled to a public switched telephone network, comprising:

a. a plurality of gateways configured to receive at least one voice call from the public switched telephone network, wherein the plurality of gateways are coupled to at least one hub;

b. a proxy table configured in each of the plurality of gateways, wherein the plurality of gateways send the at least one voice call to one of at least one proxy server; and

c. a call restoration data table configured in each of the plurality of gateways, wherein the call restoration data table provides data to restore a lost call.

2. The system as claimed in claim 1 wherein the at least one hub coupled to the plurality of gateways is configured to receive the at least one voice call from the plurality of gateways, further wherein the at least one voice call is divided by the plurality of gateways into a session initiation protocol portion and a real time protocol portion.

3. The system as claimed in claim 2 wherein the at least one hub includes the at least one proxy server, the at least one proxy server configured to receive the session initiation protocol portion of the at least one voice call.

4. The system as claimed in claim 2 further comprising at least one media server configured in the at least one hub, the at least one media server configured to receive the real time protocol portion for the at least one voice call.

5. The system as claimed in claim 1 wherein the at least one hub includes an application server coupled by an interface logic device to communicate with the at least one proxy server and the media server.

6. The system as claimed in claim 1 further comprising at least one node coupled to each of the at least one hub with a wide area network connection, wherein the at least one node includes a single proxy server and a single media server.

7. The system as claimed in claim 6 wherein the at least one node is coupled to each of the at least one hub with a local area network connection, wherein the at least one node includes the single proxy server and the single media server.

8. The system as claimed in claim 1 wherein the plurality of gateways are configured such that when one of the plurality of gateways fails, the remainder of the plurality of gateways remain operational.

9. The system as claimed in claim 1 further comprising a load balancing switch for directing any of the at least one voice calls to the plurality of gateways.

10. The system as claimed in claim 1 wherein the proxy table selects the appropriate one of the at least one proxy server based on a priority scheme.

11. The system as claimed in claim 1 wherein the data provided to the call restoration data table is transmitted to the call restoration data table in a session initiation protocol packet, further wherein the session initiation protocol packet includes a header and an SDP body.

12. The system as claimed in claim 11 wherein the data provided to the call restoration data table is stored as a key value pair, further wherein the key value pair is derived from the header and the SDP body.

13. A method of providing a high availability voice over internet protocol system, comprising:

a. configuring a plurality of gateways between a public switched telephone network and at least one hub;

b. implementing a proxy table and a call restoration data table in each of the plurality of gateways;

c. receiving in the plurality of gateways at least one voice call from the public switched telephone network;

d. dividing the at least one voice call into a session initiation protocol portion and a real time protocol portion;

e. sending the session initiation protocol portion of the at least one voice call to one of at least one proxy server, the at least one proxy server being located in the at least one hub, according to the proxy table; and

f. sending the real time protocol portion of the at least one voice call to a media server, the media server configured in the at least one hub.

14. The method as claimed in claim 13 further comprising restoring a lost call with data provided to the call restoration data table.

15. The method as claimed in claim 13 wherein the at least one hub includes an application server coupled by an interface logic device to communicate with the at least one proxy server and the media server.

16. The method as claimed in claim 13 wherein at least one node is coupled to each of the at least one hub with a wide area network connection, further wherein the at least one node includes a single proxy server and a single media server.

17. The method as claimed in claim 16 wherein the at least one node is coupled to each of the at least one hub with a local area network connection, further wherein the at least one node includes the single proxy server and the single media server.

18. The method as claimed in claim 13 wherein the plurality of gateways are configured such that when one of the plurality of gateways fails, the remainder of the plurality of gateways remain operational.

19. The method as claimed in claim 13 further comprising directing any of the at least one voice calls to the plurality of gateways with a load balancing switch.

20. The method as claimed in claim 13 wherein the proxy table selects the appropriate one of the at least one proxy server based on a priority scheme.

21. The method as claimed in claim 13 wherein the data provided to the call restoration data table is transmitted to the call restoration data table in a session initiation protocol packet, further wherein the session initiation protocol packet includes a header and an SDP body.

22. The method as claimed in claim 21 wherein the data provided to the call restoration data table is stored as a key value pair, further wherein the key value pair is derived from the header and the SDP body.

23. A high availability voice over internet protocol system coupled to a public switched telephone network, comprising:

a. means for configuring a plurality of gateways between a public switched telephone network and at least one hub;

b. means for implementing a proxy table and a call restoration data table in each of the plurality of gateways;

c. means for receiving in the plurality of gateways at least one voice call from the public switched telephone network;

d. means for dividing the at least one voice call into a session initiation protocol portion and a real time protocol portion;

e. means for sending the session initiation protocol portion of the at least one voice call to one of at least one proxy server, the at least one proxy server being located in the at least one hub, according to the proxy table; and

f. means for sending the real time protocol portion of the at least one voice call to a media server, the media server configured in the at least one hub.

24. The system as claimed in claim 23 further comprising means for restoring a lost call with data provided to the call restoration data table.

25. The system as claimed in claim 23 wherein the at least one hub includes an application server coupled by an interface logic device to communicate with the at least one proxy server and the media server.

26. The system as claimed in claim 23 wherein at least one node is coupled to each of the at least one hub with a wide area network connection, further wherein the at least one node includes a single proxy server and a single media server.

27. The system as claimed in claim 26 wherein the at least one node is coupled to each of the at least one hub with a local area network connection, further wherein the at least one node includes the single proxy server and the single media server.

28. The system as claimed in claim 23 wherein the plurality of gateways are configured such that when one of the plurality of gateways fails, the remainder of the plurality of gateways remain operational.

29. The system as claimed in claim 23 further comprising means for directing any of the at least one voice calls to the plurality of gateways with a load balancing switch.

30. The system as claimed in claim 23 wherein the proxy table selects the appropriate one of the at least one proxy server based on a priority scheme.

31. The system as claimed in claim 23 wherein the data provided to the call restoration data table is transmitted to the call restoration data table in a session initiation protocol packet, further wherein the session initiation protocol packet includes a header and an SDP body.

32. The system as claimed in claim 31 wherein the data provided to the call restoration data table is stored as a key value pair, further wherein the key value pair is derived from the header and the SDP body.

33. A method of routing session initiation protocol voice calls through a plurality of gateways using a proxy server priority table having a proxy address for each incoming call, comprising:

a. setting the proxy server priority table to a first level;

b. contacting a designated proxy when a pointer value is assigned to the proxy address, the pointer value corresponding to the designated proxy;

c. contacting a first proxy in the first level;

d. attaching the proxy address through the first proxy in the first level when the first proxy in the first level responds before a first time out value;

e. contacting a second proxy in the first level if the first proxy in the first level does not respond before the first time out value; and

f. setting the proxy server priority table to a second level when the second proxy does not exist in the first level.

34. The method as claimed in claim 33 further comprising attaching the proxy address having the pointer value to the designated proxy when the designated proxy responds before a second time out value.

35. The method as claimed in claim 34 further comprising incrementing the pointer value to the next proxy address in the first level.

36. The method as claimed in claim 33 further comprising incrementing the pointer value to an incremented pointer value when the designated proxy does not respond before the second time out value, wherein the incremented pointer value corresponds to an incremented designated proxy.

37. The method as claimed in claim 36 further comprising contacting the incremented designated proxy, the incremented pointer value corresponding to the incremented designated proxy.