System and method for maintaining a communication link

• US 6,804,254 B1
• Filed: 01/04/2000
• Issued: 10/12/2004
• Est. Priority Date: 01/04/2000
• Status: Expired due to Term

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Pearce, Christopher E., Higgins, Ronald D., Henning, Scott, Whetten, Delon R.
• Primary Examiner(s): Ton, Dang
• Assistant Examiner(s): Phan, Tri H.
• Application Number:
  US09/477,192
• Time in Patent Office: 1,743 Days
• Field of Search: 370/467, 370/401, 370/402, 370/464, 370/465, 370/466, 370/469, 370/493, 370/351, 370/352, 370/356, 370/389, 370/395.5, 370/395.52, 370/395.53, 709/200, 709/218, 709/204, 709/227, 709/231, 709/247, 709/322, 379/211.02, 379/219, 379/88.13, 379/220.01, 379/221.01, 379/243, 379/245, 379/93.09, 379/88.17, 379/93.11, 379/93.35
• US Class Current: 370/467
• CPC Class Codes: H04L 65/103 in the network
• CPC Class Codes: H04L 65/104 in the network
• CPC Class Codes: H04L 65/1043 Gateway controllers, e.g. media gateway control protocol [MGCP] controllers
• CPC Class Codes: H04L 65/1069 Session establishment or de-establishment
• CPC Class Codes: H04L 65/1096 Supplementary features, e.g. call forwarding or call holding systems providing special services or facilities to telephony subscribers H04M3/42
• CPC Class Codes: H04L 65/1101 Session protocols
• CPC Class Codes: H04M 2207/203 composed of PSTN and data network, e.g. the Internet
• CPC Class Codes: H04M 3/2281 Call monitoring, e.g. for law enforcement purposes; Call tracing; Detection or prevention of malicious calls

Abstract

A method is provided for maintaining media streaming to a telephony device. The method includes establishing a media streaming link between a first telephony device and a second telephony device using a media termination point. The media streaming between the first telephony device and the second telephony device passes through the media termination point. The method further includes receiving a request to implement a telephony feature requiring media streaming termination between the first and second telephony devices. The method also includes terminating the media streaming between the first telephony device and the media termination point while maintaining the media streaming between the second telephony device and the media termination point.

Claims

1. A method for maintaining media streaming to a telephony device, comprising:

establishing a signaling link between a first telephony device and a second telephony device;

establishing media streaming between the first telephony device and the second telephony device using a media termination point, whereby the media streaming between the first telephony device and the second telephony device passes through the media termination point;

determining whether the second telephony device utilizes a protocol incompatible with a temporary termination of the established media streaming between the first and second telephony devices;

generating the media termination point in response to a determination that the second telephony device utilizes a protocol incompatible with the temporary termination of the established media streaming between the first and second telephony devices;

receiving a request to implement a telephony feature requiring temporary termination of the established media streaming between the first and second telephony devices; and

temporarily terminating the established media streaming between the first telephony device and the media termination point while maintaining the media streaming between the second telephony device and the media termination point, and while maintaining the signaling link between the first and second telephony devices.

2. The method of claim 1, further comprising:

receiving a call initiation request indicating a desire to create a communication link between the first telephony device and the second telephony device; and

establishing the signaling link between the first telephony device and the second telephony device in response to the call initiation request.

3. The method of claim 1, wherein determining that the second telephony device utilizes a protocol incompatible with the temporary termination of the established media streaming comprises determining that the second telephony device uses a protocol that terminates the signaling link between the first telephony device and the second telephony device in response to termination of the media streaming between the first telephony device and the second telephony device.

4. The method of claim 1, wherein determining that the second telephony device utilizes a protocol incompatible with the temporary termination of the established media streaming comprises determining that the second telephony device uses H.225 call signaling.

5. The method of claim 1, wherein establishing the media streaming between the first telephony device and the second telephony device using the media termination point comprises:

associating a first logical port of the media termination point with the first telephony device;

receiving media streaming from the second telephony device at the first logical port;

modifying source address information in the received media streaming to specify a second logical port of the media termination point associated with the second telephony device; and

communicating the media streaming with the modified source address information to the first telephony device.

6. The method of claim 5, wherein associating a first logical port of the media termination point with the first telephony device comprises associating a User Datagram Protocol (UDP) logical port to enable the streaming of Internet Protocol (IP) packets.

7. The method of claim 6, wherein modifying source address information in the received media streaming comprises modifying a source IP address and port information in a header of an IP packet.

8. The method of claim 1, further comprising reestablishing the media streaming between the first telephony device and the media termination point in response to a discontinuation of the telephony feature.

9. The method of claim 1, further comprising establishing media streaming between a third telephony device and the media termination point to create a communication link between the second telephony device and the third telephony device according to the initiated telephony feature.

10. The method of claim 1, wherein receiving a request to implement a telephony feature requiring temporary termination of the established media streaming comprises receiving a request to implement a call hold feature, a call transfer feature, a call park feature, or a conference call feature.

11. A communication network, comprising:

a first telephony device utilizing a protocol compatible with a telephony feature requiring a temporary termination of established media streaming;

a second telephony device utilizing a protocol incompatible with the telephony feature requiring the temporary termination of the established media streaming; and

a media termination point generated in response to a determination that the second telephony device utilizes a protocol incompatible with the temporary termination of the established media streaming between the first and second telephony devices, the media termination point operable to maintain media streaming with the second telephony device after temporary termination of media streaming between the first telephony device and the second telephony device to enable the telephony feature requiring the temporary termination of the established media streaming between the first and second telephony devices.

12. The communication network of claim 11, further comprising a call manager operable to:

establish a signaling link between the first telephony device and the second telephony device;

establish the media streaming between the first telephony device and the second telephony device passing through the media termination point; and

temporarily terminate the established media streaming between the first telephony device and the media termination point to enable the telephony feature requiring the temporary termination of the established media streaming between the first and second telephony devices while maintaining the signaling link between the first and second telephony devices.

13. The communication network of claim 12, wherein the call manager is further operable to reestablish the temporarily terminated media streaming between the first telephony device and the media termination point.

14. The communication network of claim 12, wherein the call manager is further operable to establish media streaming between a third telephony device and the media termination point to create a communication link between the second telephony device and the third telephony device according to the telephony feature requiring the temporary termination of the established media streaming termination.

15. The communication network of claim 11, wherein the media termination point comprises a logical device implemented using software executed on one or more devices coupled to the communication network.

16. The communication network of claim 11, wherein the protocol incompatible with the telephony feature requiring the temporary termination of the established media streaming comprises H.225 call signaling.

17. The communication network of claim 11, wherein the first telephony device and the second telephony device comprise Internet Protocol (IP) telephony devices.

18. The communication network of claim 12, wherein the media streaming between the first telephony device and the media termination point, and the media streaming between the media termination point and the second telephony device comprise Real-Time Transport Protocol (RTP) media streams.

19. A communication network, comprising:

a first telephony device utilizing a protocol incompatible with a telephony feature requiring a temporary termination of established media streaming;

a second telephony device utilizing a protocol incompatible with the telephony feature requiring the temporary termination of the established media streaming;

a first media termination point operable to maintain media streaming with the first telephony device after temporary termination of the established media streaming between the first telephony device and the second telephony device to enable the telephony feature requiring the temporary termination of the established media streaming between the first and second telephony devices; and

a second media termination point operable to maintain media streaming with the second telephony device after temporary termination of the established media streaming between the first telephony device and the second telephony device to enable the telephony feature requiring the temporary termination of the established media streaming between the first and second telephony devices.

20. The communication network of claim 19, further comprising a call manager operable to:

initiate the creation of a signaling link between the first and second telephony devices;

initiate the creation of media streaming between the first telephony device and the first media termination point, between the first media termination point and the second media termination point, and between the second media termination point and the second telephony device; and

temporarily terminate the established media streaming between the first and second media termination points to enable the telephony feature requiring the temporary termination of the established media streaming between the first and second telephony devices, while maintaining the signaling link between the first and second telephony devices.

21. The communication network of claim 20, wherein the call manager is further operable to reestablish the media streaming between the first and second media termination points.

22. The communication network of claim 20, wherein the call manager is further operable to establish media streaming between a third telephony device and the second media termination point to create a communication link between the second telephony device and the third telephony device according to the telephony feature requiring the temporary termination of the established media streaming.

23. The communication network of claim 19, wherein the first and second media termination points comprise logical devices implemented using software executed on one or more devices coupled to the communication network.

24. The communication network of claim 19, wherein the protocol incompatible with the telephony feature requiring media streaming termination comprises H.225 call signaling.

25. The communication network of claim 19, wherein the first telephony device and the second telephony device are Internet Protocol (IP) telephony devices.

26. The communication network of claim 20, wherein the media streaming between the first telephony device and the first media termination point, the media streaming between the first media termination point and the second media termination point, and the media streaming between and the second media termination point and the second telephony device comprise Real-Time Transport Protocol (RTP) media streams.

27. A media termination point for use in a communication network including a first telephony device utilizing a protocol compatible with a telephony feature requiring a temporary termination of established media streaming and a second telephony device utilizing a protocol incompatible with the telephony feature requiring the temporary termination of the established media streaming, the media termination point comprising:

a first logical port associated with the first telephony device;

a second logical port associated with the second telephony device;

an address modification module operable to modify source address information in media streaming received at the first logical port from the second telephony device to specify the second logical port of the media termination point; and

a transmission module operable to communicate the media streaming with the modified source address information to the first telephony device if the telephony feature requiring the temporary termination of the established media streaming is not implemented, and further operable to discard the media streaming received at the first logical port from the second telephony device during an implementation of the telephony feature requiring the temporary termination of the established media streaming.

28. The media termination point of claim 27, wherein the first and second logical ports are User Datagram Protocol (UDP) logical ports.

29. The media termination point of claim 27, wherein the address modification module is operable to modify a source IP address and port information in a header of an IP packet.

30. A call manager for use in a communication network including a first telephony device utilizing a protocol compatible with a telephony feature requiring a temporary termination of established media streaming and a second telephony device utilizing a protocol incompatible with the telephony feature requiring the temporary termination of the established media streaming, the call manager comprising:

a call control module operable to establish a signaling link between the first telephony device and the second telephony device; and

a media control module operable to establish the media streaming between the first telephony device and the second telephony device passing through a media termination point, and further operable to temporarily terminate the established media streaming between the first telephony device and the media termination point to enable the telephony feature requiring the temporary termination of the established media streaming between the first and second telephony devices while maintaining the signaling link between the first and second telephony devices.

31. The call manager of claim 30, wherein the media control module is further operable to determine that the second telephony device utilizes a protocol incompatible with the temporary termination of the established media streaming, and to generate the media termination point in response to determining that the second telephony device utilizes the protocol incompatible with the temporary termination of the established media streaming.

32. The call manager of claim 30, wherein the media control module is further operable to reestablish the media streaming between the first telephony device and the media termination point.

33. The call manager of claim 30, wherein:

the call control module is further operable to establish a signaling link with a third telephony device; and

the media control module is further operable to establish media streaming between the third telephony device and the media termination point to create a communication link between the second telephony device and the third telephony device according to the telephony feature requiring the temporary termination of the established media streaming.

34. Call manager software embodied in a computer-readable medium and operable, when executed on a computer, to perform the following steps:

establishing a signaling link between a first telephony device and a second telephony device,

establishing the media streaming between the first telephony device and the second telephony device using a media termination point, whereby the media streaming between the first telephony device and the second telephony device passes through the media termination point;

determining whether the second telephony device utilizes a protocol incompatible with a temporary termination of the established media streaming between the first and second telephony devices;

generating the media termination point in response to a determination that the second telephony device utilizes a protocol incompatible with the temporary termination of the established media streaming between the first and second telephony devices;

receiving a request to implement a telephony feature requiring temporary termination of the established media streaming between the first and second telephony devices; and

temporarily terminating the established media streaming between the first telephony device and the media termination point while maintaining the media streaming between the second telephony device and the media termination point, and while maintaining the signaling link between the first and second telephony devices.

35. The call manager software of claim 34, further operable to perform the following steps:

receiving a call initiation request indicating a desire to create a communication link between the first telephony device and the second telephony device; and

establishing signaling the signaling link between the first telephony device and the second telephony device in response to the call initiation request.

36. The call manager software of claim 34, wherein determining that the second telephony device utilizes a protocol incompatible with the temporary termination of the established media streaming comprises determining that the second telephony device uses a protocol that terminates a signaling link between the first telephony device and the second telephony device in response to a termination of the media streaming between the first telephony device and the second telephony device.

37. The call manager software of claim 34, wherein determining that the second telephony device utilizes a protocol incompatible with the temporary termination of the established media streaming comprises determining that the second telephony device uses H.225 call signaling.

38. The call manager software of claim 34, wherein establishing the media streaming between the first telephony device and the second telephony device using the media termination point comprises:

associating a first logical port of the media termination point with the first telephony device;

receiving media streaming from the second telephony device at the first logical port;

modifying source address information in the received media streaming to specify a second logical port of the media termination point associated with the second telephony device; and

communicating the media streaming with the modified source address information to the first telephony device.

39. The call manager software claim 38, wherein associating a first logical port of the media termination point with the first telephony device comprises associating a User Datagram Protocol (UDP) logical port to enable the streaming of Internet Protocol (IP) packets.

40. The call manager software of claim 39, wherein modifying source address information in the received media streaming comprises modifying a source IP address and port information in a header of an IP packet.

41. The call manager software of claim 34, further operable to reestablish the media streaming between the first telephony device and the media termination point in response to a discontinuation of the telephony feature.

42. The call manager software of claim 34, further operable to establish media streaming between a third telephony device and the media termination point to create a communication link between the second telephony device and the third telephony device according to the telephony feature.