Method and apparatus for using an external transcoder in a communication session

• US 7,756,104 B1
• Filed: 12/12/2000
• Issued: 07/13/2010
• Est. Priority Date: 12/12/2000
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Wong, Wilfred F, Chan, Johnny C, Sarkar, Shantanu
• Primary Examiner(s): Pham; Chi H.
• Assistant Examiner(s): HOM, SHICK C
• Application Number:
  US09/735,739
• Time in Patent Office: 3,500 Days
• Field of Search: 370/236, 370/252, 370/356, 370/389, 370/392, 370/401, 370/402, 370/465, 370/467, 370/469
• US Class Current: 370/352
• CPC Class Codes: H04L 65/1069 Session establishment or de-establishment
• CPC Class Codes: H04L 65/80 Responding to QoS
• CPC Class Codes: H04L 69/24 Negotiation of communication capabilities
• CPC Class Codes: H04M 7/0072 Speech codec negotiation H04L65/1069 takes precedence

Abstract

A system includes the ability to establish a communication session between stations using protocol capabilities of an external transcoder. The stations may establish a communication session by exchanging protocol capabilities which include a protocol capability of at least one remotely located transcoder. The communication session may then be established using appropriate signalling protocol, including peer-to-peer signalling protocols.

Claims

1. A method for establishing a call with a station using a transcoder, comprising:

communicating protocol capabilities to the station in response to initiation of the call, wherein the protocol capabilities comprise the protocol capability of at least one remotely located transcoder;

determining whether the protocol capability of the transcoder matches the protocol capability of the station;

selecting the transcoder from a plurality of transcoders based on a priority;

initiating a transfer of the call to the transcoder to establish a first link between the station and the transcoder; and

initiating establishment of a second link with the transcoder to enable media exchange with the station using the protocol capability of the transcoder.

2. The method of claim 1, wherein communicating protocol capabilities is performed using a peer-to-peer signalling protocol.

3. The method of claim 1, wherein communicating protocol capabilities is performed using H.323 signalling protocol.

4. The method of claim 1, wherein initiating the transfer of the call comprises:

initiating a consult transfer;

receiving a session identifier from the transcoder; and

communicating the session identifier to the station.

5. The method of claim 4, wherein initiating establishment of the second link with the transcoder comprises communicating to the transcoder a call setup request having the session identifier.

6. The method of claim 1, wherein media comprises voice information and the protocol capability of the transcoder comprises a voice compression protocol.

7. A communication device, comprising:

an interface operable to communicate with a network;

a memory operable to store protocol capabilities in a plurality of entries, each entry corresponding to a remotely located transcoder and specifying an address of the transcoder and at least one protocol capability of the transcoder; and

a processor coupled to the interface and the memory, the processor operable, in response to initiation of a call, to generate a first signal to communicate the protocol capabilities to a station, the protocol capabilities comprising the protocol capability of at least one remotely located transcoder, the processor further operable to generate a second signal to initiate transfer of the call to a selected transcoder, the processor further operable to generate a third signal to initiate communication with the selected transcoder to enable media exchange with the station using the selected transcoder.

8. The communication device of claim 7, wherein the first signal, the second signal, and the third signal comply with H.323 signalling protocol.

9. The communication device of claim 7, wherein the second signal comprises a consult transfer to the transcoder that produces a session identifier.

10. The communication device of claim 9, wherein the third signal comprises a call setup request having the session identifier.

11. The communication device of claim 7, wherein media comprises voice information and the protocol capability of the transcoder comprises a voice compression protocol.

31. The communication device of claim 7, wherein the first signal, the second signal, and the third signal comprise peer-to-peer signalling protocol.

32. The communication device of claim 31, wherein each entry in the memory further comprises a priority for selection of the corresponding transcoder.

12. A method for establishing a communication session between a first station and a second station, the method comprising:

establishing a session identifier associated with the communication session responsive to a protocol capabilities communication between the first station and the second station;

receiving a determination whether the protocol capability of a transcoder matches the protocol capabilities of the first station and the second station;

receiving a selection of the transcoder from a plurality of transcoders based on a priority;

establishing a first link between the first station and the transcoder using the session identifier;

establishing a second link between the second station and the transcoder using the session identifier; and

exchanging media between the first station and the second station using the first link and the second link.

13. The method of claim 12, wherein establishing the session identifier associated with the communication session comprises:

receiving a consult transfer from the first station; and

communicating the session identifier associated with the consult transfer to the first station.

14. The method of claim 12, wherein establishing the first link comprises receiving a call setup request having the session identifier.

15. The method of claim 12, wherein establishing the second link comprises receiving a transfer notification having the session identifier.

16. The method of claim 12, wherein exchanging media comprises:

associating the first link and the second link using the session identifier;

transcoding first information received from the first link for communication to the second link; and

transcoding second information received from the second link for communication to the first link.

17. The method of claim 12, wherein the steps of establishing the first link and establishing the second link are performed using peer-to-peer signalling protocols.

18. The method of claim 12, wherein the steps of establishing the first link and establishing the second link are performed using H.323 signalling protocols.

19. Logic encoded in media for establishing a call with a station using a transcoder, the logic operable to perform the following steps:

communicating protocol capabilities to the station in response to initiation of the call, wherein the protocol capabilities comprise a protocol capability of at least one remotely located transcoder;

determining whether the protocol capability of the transcoder matches a protocol capability of the station;

selecting the transcoder from a plurality of transcoders based on a priority;

initiating a transfer of the call to the transcoder to establish a first link between the station and the transcoder; and

initiating establishment of a second link with the transcoder to enable media exchange with the station using the protocol capability of the transcoder.

20. The logic of claim 19, wherein communicating protocol capabilities is performed using a peer-to-peer signalling protocol.

21. The logic of claim 19, wherein communicating protocol capabilities is performed using H.323 signalling protocol.

22. The logic of claim 19, wherein initiating the transfer of the call comprises:

initiating a consult transfer;

receiving a session identifier from the transcoder; and

communicating the session identifier to the station.

23. The logic of claim 22, wherein initiating establishment of the second link with the transcoder comprises communicating to the transcoder a call setup request having the session identifier.

24. The logic of claim 19, wherein media comprises voice information and the protocol capability of the transcoder comprises a voice compression protocol.

25. An apparatus for establishing a call with a station using a transcoder, comprising:

means for communicating protocol capabilities to a station in response to initiation of the call, wherein the protocol capabilities comprise the protocol capability of at least one remotely located transcoder;

means for determining whether the protocol capability of the transcoder matches a protocol capability of the station;

means for selecting the transcoder from a plurality of transcoders based on a priority;

means for initiating a transfer of the call to the transcoder to establish a first link between the station and the transcoder; and

means for initiating establishment of a second link with the transcoder to enable media exchange with the station using the protocol capability of the transcoder.

26. The apparatus of claim 25, wherein means for communicating protocol capabilities is performed using a peer-to-peer signalling protocol.

27. The apparatus of claim 25, wherein means for initiating the transfer of the call comprises:

means for initiating a consult transfer;

means for receiving a session identifier from the transcoder; and

means for communicating the session identifier to the station.

28. The apparatus of claim 25, wherein media comprises voice information and the protocol capability of the transcoder comprises a voice compression protocol.

29. A method for establishing a call with a station using a transcoder, comprising:

storing protocol capabilities in a plurality of entries in a memory, each entry corresponding to a remotely located transcoder and specifying an address of the transcoder and at least one protocol capability of the transcoder;

communicating protocol capabilities to the station in response to initiation of the call, the protocol capabilities comprising the protocol capability of at least one remotely located transcoder;

initiating a transfer of the call to a selected transcoder to establish a first link between the station and the selected transcoder; and

initiating establishment of a second link with the selected transcoder to enable media exchange with the station using the selected transcoder.

30. A method for establishing a call with a station using a transcoder, comprising:

communicating protocol capabilities to the station in response to initiation of the call, wherein the protocol capabilities comprise the protocol capability of at least one remotely located transcoder;

selecting the transcoder from a plurality of transcoders if the protocol capability of the transcoder matches the protocol capability of the station;

initiating a transfer of the call to the transcoder to establish a first link between the station and the transcoder; and

initiating establishment of a second link with the transcoder to enable media exchange with the station using the transcoder.

33. Logic encoded in media for establishing a call with a station using a transcoder, the logic operable to perform the following steps:

storing protocol capabilities in a plurality of entries in a memory, each entry corresponding to a remotely located transcoder and specifying an address of the transcoder and at least one protocol capability of the transcoder;

communicating protocol capabilities to the station in response to initiation of the call, the protocol capabilities comprising the protocol capability of at least one remotely located transcoder;

initiating a transfer of the call to a selected transcoder to establish a first link between the station and the selected transcoder; and

initiating establishment of a second link with the selected transcoder to enable media exchange with the station using the selected transcoder.

34. Logic encoded in media for establishing a call with a station using a transcoder, the logic operable to perform the following steps:

communicating protocol capabilities to the station in response to initiation of the call, wherein the protocol capabilities comprise the protocol capability of at least one remotely located transcoder;

selecting the transcoder from a plurality of transcoders if the protocol capability of the transcoder matches the protocol capability of the station;

initiating a transfer of the call to the transcoder to establish a first link between the station and the transcoder; and

initiating establishment of a second link with the transcoder to enable media exchange with the station using the transcoder.

35. An apparatus for establishing a call with a station using a transcoder, comprising:

means for storing protocol capabilities in a plurality of entries in a memory, each entry corresponding to a remotely located transcoder and specifying an address of the transcoder and at least one protocol capability of the transcoder;

means for communicating protocol capabilities to the station in response to initiation of the call, the protocol capabilities comprising the protocol capability of at least one remotely located transcoder;

means for initiating a transfer of the call to a selected transcoder to establish a first link between the station and the selected transcoder; and

means for initiating establishment of a second link with the selected transcoder to enable media exchange with the station using the selected transcoder.