Apparatus and method for allocating call resources during a conference call

• US 7,003,086 B1
• Filed: 01/18/2001
• Issued: 02/21/2006
• Est. Priority Date: 01/18/2001
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Sarkar, Shantanu, Shaffer, Shmuel
• Primary Examiner(s): Matar, Ahmad F.
• Assistant Examiner(s): AL AUBAIDI, RASHA S
• Application Number:
  US09/766,424
• Time in Patent Office: 1,860 Days
• Field of Search: 379/202.01, 379/212.01, 370/16, 370/228, 370/260, 370/253, 725/109, 348/14.11
• US Class Current: 379/202.01
• CPC Class Codes: H04L 12/1813 for computer conferences, e.g. chat rooms instant messaging H04L51/04; protocols for multimedia communication H04L65/1101; arrangements for multi-party communication H04L65/403; telephonic conference arrangements H04M3/56; television conference systems H04N7/15
• CPC Class Codes: H04L 65/103 in the network
• CPC Class Codes: H04L 65/104 in the network
• CPC Class Codes: H04L 65/1101 Session protocols
• CPC Class Codes: H04L 65/403 Arrangements for multi-party communication, e.g. for conferences data switching systems for conference H04L12/18; arrangements for connecting several subscribers to a common circuit, i.e. affording conference facilities H04M3/56; television conferencing systems H04N7/15
• CPC Class Codes: H04M 3/56 Arrangements for connecting several subscribers to a common circuit, i.e. affording conference facilities video conference systems H04N7/15
• 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 method and apparatus for allocating call resources during a conference call are disclosed. A conference call between a plurality of clients is conducted on a first call resource. The clients communicate media streams to the first call resource for mixing. A media gateway identifies a second call resource to conduct the conference call and mix the media streams, and transfers the conference call from the first call resource to the second call resource without suspending communication of a plurality of mixed media streams received by the clients.

Claims

1. A method for allocating a plurality of call resources during a conference call, comprising:

conducting a conference call between three or more clients using a first call resource;

identifying a second call resource available to conduct the conference call;

transferring the conference call from the first call resource to the second call resource without suspending communication of a plurality of mixed media streams received by the clients; and

wherein transferring comprises;

generating a first mixed media stream at the first call resource and a second mixed media stream at the second call resource;

modifying synchronization information in the second mixed media stream to match synchronization information in the first mixed media stream;

terminating the first mixed media stream to end communication with the first call resource upon confirming that the modified second mixed media stream is valid; and

communicating the modified second mixed media stream to the clients.

2. The method of claim 1, further comprising introducing a delay in a selected one of the first mixed media stream and the second mixed media stream to synchronize the first mixed media stream and the second mixed media stream.

3. The method of claim 1, wherein modifying synchronization information comprises:

instructing the second call resource to adjust synchronization information in the second mixed media stream; and

receiving the second mixed media stream with the adjusted synchronization information.

4. The method of claim 1, wherein synchronization information comprises at least a selected one of a timestamp and a sequence number.

5. The method of claim 1, wherein:

the first mixed media stream comprises a first sequence of real-time transport protocol (RTP) packets;

the second mixed media stream comprises a second sequence of RTP packets; and

the modified second mixed media stream is valid when the second sequence of RTP packets matches the first sequence of RTP packets.

6. The method of claim 1, wherein the clients are unaware of the transfer of the conference call from the first call resource to the second call resource.

7. A method for allocating a plurality of call resources during a conference call, comprising:

conducting a conference call between three or more clients using a first call resource;

identifying a second call resource available to conduct the conference call;

transferring the conference call from the first call resource to the second call resource without suspending communication of a plurality of mixed media streams received by the clients; and

wherein conducting the conference call comprises;

communicating, to the first call resource, a first media stream generated by one of the clients participating in the conference call; and

communicating, to the one of the clients, a first mixed media stream received from the first call resource;

transferring the conference call comprises;

duplicating the first media stream to create a second media stream;

communicating the second media stream to the second call resource;

receiving a second mixed media stream from the second call resource;

terminating the first mixed media stream to end communication with the first call resource upon confirming that a modified second mixed media stream is valid;

communicating the modified second mixed media stream to the one of the clients; and

further comprising;

instructing the second call resource to adjust synchronization information in the second mixed media stream; and

receiving the second mixed media stream with the adjusted synchronization information.

8. A communication system, comprising:

three or more clients operable to couple to a packet-based network, the clients further operable to initiate or join a conference call;

a first call resource operable to couple to the packet based network;

a second call resource operable to couple to the packet-based network at a different physical location than the first call resource;

a media gateway operable to couple to the packet-based network, the media gateway further operable to transfer the conference call from the first call resource to the second call resource without suspending communication of a plurality of mixed media streams received by the clients; and

wherein;

the first call resource is further operable to generate a first mixed media stream;

the second call resource is further operable to generate a second mixed media stream;

the media gateway is further operable to;

modify synchronization information in the second mixed media stream to match synchronization information in the first mixed media stream;

terminate the first mixed media stream to end communication with the first call resource upon confirming that the modified second mixed media stream is valid; and

communicate the modified second mixed media stream to the clients.

9. The communication system of claim 8, wherein the media gateway is further operable to introduce a delay in a selected one of the first mixed media stream and the second mixed media stream to synchronize the first mixed media stream and the second mixed media stream.

10. The communication system of claim 8, wherein the media gateway modifies synchronization information by:

instructing the second call resource to adjust synchronization information in the second mixed media stream; and

receiving the second mixed media stream with the adjusted synchronization information.

11. The communication system of claim 8, wherein the synchronization information comprises at least a selected one of a timestamp and a sequence number.

12. The communication system of claim 8, wherein

the first mixed media stream comprises a first sequence of real-time transport protocol (RTP) packets;

the second mixed media stream comprises a second sequence of RTP packets; and

the modified second mixed media stream is valid when the second sequence of RTP packets matches the first sequence of RTP packets.

13. The communication system of claim 8, wherein the clients are unaware of the transfer of the conference call from the first call resource to the second call resource.

14. The communication system of claim 8, wherein the plurality of clients are selected from a group consisting essentially of a conventional telephone coupled to the packet-based network via a gateway, a wireless phone coupled to the packet-based network via the gateway, an Internet Protocol (IP) phone or a computer including a voice teleconferencing application.

15. The communication system of claim 8, wherein the packet-based network comprises an Internet Protocol (IP) network.

16. A communication system, comprising:

three or more clients operable to couple to a packet-based network, the clients further operable to initiate or join a conference call;

a first call resource operable to couple to the packet-based network;

a second call resource operable to couple to the packet-based network at a different physical location than the first call resource;

a media gateway operable to couple to the packet-based network, the media gateway further operable to transfer the conference call from the first call resource to the second call resource without suspending communication of a plurality of mixed media streams received by the clients;

wherein one of the clients participating in the conference call is operable to communicate a first media stream to the first call resource;

wherein the first call resource is further operable to communicate a first mixed media stream to the one of the clients; and

the media gateway is further operable to;

duplicate the first media stream to create a second media stream;

communicate the second media stream to the second call resource;

receive a second mixed media stream from the second call resource;

terminate the first mixed media stream to end communication with the first call resource upon confirming that a modified second mixed media stream is valid;

communicate the modified second mixed media stream to the one of the clients;

instruct the second call resource to adjust synchronization information in the second mixed media stream; and

receive the second mixed media stream with the adjusted synchronization information.

17. A media gateway, comprising:

an interface operable to couple to a communication network, the interface further operable to receive media streams communicated by three or more clients participating in a conference call;

a processing module coupled to the interface, the processing module operable to transfer the conference call from a first call resource to a second call resource without suspending communication of a plurality of mixed media streams received by the clients; and

wherein the processing module is further operable to;

receive a first mixed media stream generated by the first call resource and a second mixed media stream generated by the second call resource;

modify synchronization information in the second mixed media stream to match synchronization information in the first mixed media stream;

terminate the first mixed media stream to end communication with the first call resource upon confirming that the modified second mixed media stream is valid; and

communicate the modified second mixed media stream to the clients.

18. The media gateway of claim 17, wherein the processing module is further operable to introduce a delay in a selected one of the first mixed media stream and the second mixed media stream to synchronize the first mixed media stream and the second mixed media stream.

19. The media gateway of claim 17, wherein the processing module modifies synchronization information by:

instructing the second call resource to adjust synchronization information in the second mixed media stream; and

receiving the second mixed media stream with the adjusted synchronization information.

20. The media gateway of claim 17, wherein the synchronization information comprises at least a selected one of a timestamp and a sequence number.

21. The media gateway of claim 17, wherein:

the first mixed media stream comprises a first sequence of real-time transport protocol (RTP) packets;

the second mixed media stream comprises a second sequence of RTP packets; and

the modified second mixed media stream is valid when the second sequence of RTP packets matches the first sequence of RTP packets.

22. The media gateway of claim 17, wherein the clients are unaware of the transfer of the conference call from the first call resource to the second call resource.

23. A media gateway, comprising:

an interface operable to couple to a communication network, the interface further operable to receive media streams communicated by three or more clients participating in a conference call;

a processing module coupled to the interface, the processing module operable to transfer the conference call from a first call resource to a second call resource without suspending communication of a plurality of mixed media streams received by the clients; and

wherein the processing module is further operable to;

communicate a first media stream generated by one of the clients participating in the conference call to the first call resource;

communicate a first mixed media stream received from the first call resource to the one of the clients;

duplicate the first media stream to create a second media stream;

communicate the second media stream to the second call resource;

receive a second mixed media stream from the second call resource;

terminate the first mixed media stream to end communication with the first call resource upon confirming that a modified second mixed media stream is valid;

communicate the modified second mixed media stream to the one of the clients;

instruct the second call resource to adjust synchronization information in the second mixed media stream; and

receive the second mixed media stream with the adjusted synchronization information.

24. Logic encoded in media for allocating a plurality of call resources during a conference call and operable to perform the following steps:

conducting a conference call between three or more clients using a first call resource;

identifying a second call resource available to conduct the conference call;

transferring the conference call from the first call resource to the second call resource without suspending communication of a plurality of mixed media streams received by the clients; and

wherein transferring comprises;

generating a first mixed media stream at the first call resource and a second mixed media stream at the second call resource;

modifying synchronization information in the second mixed media stream to match synchronization information in the first mixed media stream;

terminating the first mixed media stream to end communication with the first call resource upon confirming that the modified second mixed media stream is valid; and

communicating the modified second mixed media stream to the clients.

25. The logic encoded in media of claim 24, further comprising introducing a delay in a selected one of the first mixed media stream and the second mixed media stream to synchronize the first mixed media stream and the second mixed media stream.

26. The logic encoded in media of claim 24, wherein modifying synchronization information comprises:

instructing the second call resource to adjust synchronization information in the second mixed media stream; and

receiving the second mixed media stream with the adjusted synchronization information.

27. The logic encoded in media of claim 24, wherein synchronization information comprises at least a selected one of a timestamp and a sequence number.

28. The logic encoded in media of claim 24, wherein:

the first mixed media stream comprises a first sequence of real-time transport protocol (RTP) packets;

the second mixed media stream comprises a second sequence of RTP packets; and

the modified second mixed media stream is valid when the second sequence of RTP packets matches the first sequence of RTP packets.

29. The logic encoded in media of claim 24, wherein the clients are unaware of the transfer of the conference call from the first call resource to the second call resource.

30. Logic encoded in media for allocating a plurality of call resources during a conference call and operable to perform the following steps:

conducting a conference call between three or more clients using a first call resource;

identifying a second call resource available to conduct the conference call;

transferring the conference call from the first call resource to the second call resource without suspending communication of a plurality of mixed media streams received by the clients;

wherein conducting the conference call comprises;

communicating, to the first call resource, a first media stream generated by one of the clients participating in the conference call; and

communicating, to the one of the clients, a first mixed media stream received from the first call resource; and

wherein transferring the conference call comprises;

duplicating the first media stream to create a second media stream;

communicating the second media stream to the second call resource;

receiving a second mixed media stream from the second call resource;

terminating the first mixed media stream to end communication with the first call resource upon confirming that a modified second mixed media stream is valid;

communicating the modified second mixed media stream to the clients;

instructing the second call resource to adjust synchronization information in the second mixed media stream; and

receiving the second mixed media stream with the adjusted synchronization information.

31. An apparatus for allocating a plurality of call resources during a conference call, comprising:

means for conducting a conference call between three or more clients using a first call resource;

means for identifying a second call resource available to conduct the conference call;

means for transferring the conference call from the first call resource to the second call resource without suspending communication of a plurality of mixed media streams received by the clients;

means for generating a first mixed media stream at the first call resource and a second mixed media stream at the second call resource;

means for modifying synchronization information in the second mixed media stream to match synchronization information in the first mixed media stream;

means for terminating the first mixed media stream to end communication with the first call resource upon confirming that the modified second mixed media stream is valid; and

means for communicating the modified second mixed media stream to the clients.