System for terminating multicast channel and data broadcast when at least two second endpoints do not transmit positive acknowledgement message to first endpoint

Abstract

A method and apparatus for optimizing transmission of data to a plurality of second endpoints in a system wherein a first endpoint is providing data to the plurality of second endpoints each connected by a point-to-point communication channels. This may be useful in teleconferencing applications with a plurality of participants (endpoints) or broadcast server applications. The first endpoint activates a multicast communication channel having a first multicast address and commences broadcast of the data over the multicast communication channel. The first endpoint transmits a request message to each of the plurality of second endpoints in order to query each of the second endpoints whether they can receive transmissions broadcast to the first multicast address. Certain of the plurality of second endpoints transmit an acknowledgment message if they can receive transmissions broadcast to the first multicast address, and the first endpoint receives the acknowledgment message. Then, for each acknowledgment message received from certain of the plurality of second endpoints, the first endpoint deactivates the point-to-point communication channel and the certain of the plurality of second endpoints.

What is claimed is: 
     
       1. In a system wherein a first endpoint is providing data to a plurality of second endpoints each connected by a point-to-point communication channel with said first endpoint, an automatic method for optimizing the transmission of said data to said plurality of second endpoints comprising the following steps:
 a. said first endpoint activating a multicast communication channel having a first multicast address and commencing broadcast of said data over said multicast communication channel;   b. Said first endpoint transmitting a request message to each of said plurality of second endpoints in order to query each of said second endpoints whether they can receive transmissions broadcast to said first multicast address;   c. certain of said plurality of second endpoints transmitting an acknowledgment message and said first endpoint receiving said acknowledgment message;   d. for each said acknowledgment message received from said certain of said plurality of second endpoints which indicates that said certain of said plurality of second endpoints can receive transmissions broadcast to said first multicast address, deactivating said point-to-point communication channel with said first endpoint and said certain of said plurality of second endpoints; and   e. terminating said broadcast of said data and said multicast communication channel if at least two of said plurality of second endpoints do not transmit said acknowledgment messages containing a positive acknowledgment.   
     
     
       2. The method of  claim 1  further comprising the step of receiving detach messages from certain of said plurality of second endpoints, and if at least two of said plurality of second endpoints are not receiving said data, then terminating said broadcast of said data and said multicast communication channel. 
     
     
       3. The method of  claim 1  wherein said each acknowledgment message includes a response code. 
     
     
       4. The method of  claim 3  wherein said response code indicates whether each said certain of said plurality of second endpoints can receive transmissions broadcast to said first multicast address. 
     
     
       5. The method of  claim 1  wherein said data includes teleconference data. 
     
     
       6. The method of  claim 1  further comprising, prior to said step of said first endpoint activating said multicast communication channel having a first multicast address, determining whether more than one of said plurality of second endpoints is coupled to said first endpoint on a single communication medium, and if not, aborting said method. 
     
     
       7. The method of  claim 6  further comprising, prior to said first endpoint activating said multicast communication channel having said first multicast address, determining whether said single communication medium supports broadcasting to said first multicast address. 
     
     
       8. The method of  claim 1  wherein said data includes teleconference data between said first endpoint and said plurality of second endpoints. 
     
     
       9. An apparatus in a first endpoint for transmitting data to a plurality of second endpoints receiving said data from said first endpoint on point-to-point communication channels comprising:
 a. a circuit for activating a multicast communication channel having a first multicast address and commencing broadcast of said data over said multicast communication channel;   b. a circuit for transmitting a request message to each of said plurality of second endpoints in order to query each of said second endpoints whether they can receive transmissions broadcast to said first multicast address;   c. a circuit for receiving acknowledgment messages, if any, from certain of said plurality of second endpoints;   d. a circuit for deactivating each said point-to-point communication channel with said certain of said plurality of second endpoints responsive to receiving each said acknowledgment message; and   e. a circuit for terminating said broadcast of said data and said multicast communication channel if at least two of said acknowledgment messages containing a positive acknowledgment are not received.   
     
     
       10. The apparatus of  claim 9  further comprising a circuit for receiving detach messages from others of said plurality of second endpoints, and if at least two of said plurality of second endpoints are not receiving said data, then terminating said broadcast of said data and said multicast communication channel. 
     
     
       11. The apparatus of  claim 9  wherein said each acknowledgment message includes a response code. 
     
     
       12. The apparatus of  claim 11  wherein said response code indicates whether each of said certain of said plurality of second endpoints can receive transmissions broadcast to said first multicast address. 
     
     
       13. The apparatus of  claim 9  wherein said data includes teleconference data. 
     
     
       14. The apparatus of  claim 9  further comprising a detection circuit operative prior to said first endpoint activating said multicast communication channel having said first multicast address for determining whether more than one of said plurality of second endpoints is coupled to said first endpoint on a single communication medium, and if not, not activating said circuits b and c. 
     
     
       15. The apparatus of  claim 14  further comprising, prior to activation of said detection circuit a circuit for determining whether said single communication medium supports broadcasting to said first multicast address. 
     
     
       16. In a system wherein data is provided to a plurality of endpoints connected by a point-to-point communication channel, an automatic method for optimizing data transmission comprising:
 querying at least a subset of the endpoints in order to determine whether they can receive transmissions broadcast to a first multicast address;   receiving, from at least one of said endpoints, an acknowledgment message;   for at least one received acknowledgment message indicating that an endpoint can receive transmissions broadcast to said first multicast address and where a multicast communication channel having the first multicast address has been activated, deactivating said point-to-point communication channel with the endpoint from which said message is received; and   terminating the multicast communication channel having the first multicast address if at least two of said endpoints do not transmit an acknowledgment message containing a positive acknowledgement.   
     
     
       17. The method of claim 16, further comprising:
 responsive to receiving at least one acknowledgment message indicating that an endpoint can receive transmissions broadcast to said first multicast address, commencing multicasting.   
     
     
       18. The method of claim 16, further comprising:
 responsive to failing to receive an acknowledgment message from each of the queried endpoints, terminating multicasting.   
     
     
       19. The method of claim 16, further comprising:
 prior to querying, activating the multicast communication channel having the first multicast address and commencing broadcast of data over said multicast communication channel; and   terminating said broadcast of said data if at least two of said endpoints do not transmit an acknowledgment message containing a positive acknowledgement.   
     
     
       20. The method of claim 16, further comprising receiving detach messages from certain of said plurality of endpoints, and if at least one of said plurality of second endpoints are not receiving said data, then terminating multicasting. 
     
     
       21. The method of claim 16, wherein each acknowledgment message includes a response code. 
     
     
       22. The method of claim 21, wherein said response code indicates whether certain of said plurality of endpoints can receive transmissions broadcast to said first multicast address. 
     
     
       23. The method of claim 16, wherein said data includes teleconference data. 
     
     
       24. The method of claim 16, further comprising, prior to querying:
 responsive to less than two of said plurality of endpoints being coupled on a single communication medium; aborting the method.   
     
     
       25. The method of claim 24, further comprising, prior to querying:
 determining whether said single communication medium supports broadcasting to said first multicast address.   
     
     
       26. The method of claim 16, wherein said data includes teleconference data to said plurality of second endpoints. 
     
     
       27. In a system wherein data is provided to a plurality of endpoints connected by a point-to-point communication channel, an apparatus for optimizing data transmission comprising:
 a circuit for querying at least a subset of the endpoints in order to determine whether they can receive transmissions broadcast to a first multicast address;   a circuit for receiving, from at least one of said endpoints, an acknowledgment message;   a circuit for, for at least one received acknowledgment message indicating that an endpoint can receive transmissions broadcast to said first multicast address and where a multicast communication channel having the first multicast address has been activated, deactivating said point-to-point communication channel with the endpoint from which the message is received; and   a circuit for terminating the multicast communication channel having the first multicast address if at least two of said endpoints do not transmit an acknowledgment message containing a positive acknowledgement.   
     
     
       28. The apparatus of claim 27, further comprising:
 a circuit for, responsive to receiving at least one acknowledgment message indicating that an endpoint can receive transmissions broadcast to said first multicast address, commencing multicasting.   
     
     
       29. The apparatus of claim 27, further comprising:
 a circuit for, responsive to failing to receive an acknowledgment message from each of the queried endpoints, terminating multicasting.   
     
     
       30. The apparatus of claim 27, further comprising a circuit for:
 prior to querying, activating the multicast communication channel having the first multicast address and commencing broadcast of data over said multicast communication channel; and   terminating said broadcast of said data if at least two of said endpoints do not transmit an acknowledgment message containing a positive acknowledgement.   
     
     
       31. The apparatus of claim 27 further comprising a circuit for receiving detach messages from certain of said plurality of endpoints, and if at least one of said plurality of second endpoints are not receiving said data, then terminating multicasting. 
     
     
       32. The apparatus of claim 27 wherein each acknowledgment message includes a response code. 
     
     
       33. The apparatus of claim 32 wherein said response code indicates whether certain of said plurality of endpoints can receive transmissions broadcast to said first multicast address. 
     
     
       34. The apparatus of claim 27 wherein said data includes teleconference data. 
     
     
       35. The apparatus of claim 27 further comprising a circuit for, prior to querying:
 responsive to less than two of said plurality of endpoints being coupled on a single communication medium; aborting the apparatus.   
     
     
       36. The apparatus of claim 35 further comprising a circuit for, prior to querying:
 determining whether said single communication medium supports broadcasting to said first multicast address.   
     
     
       37. The apparatus of claim 27 wherein said data includes teleconference data to said plurality of second endpoints. 
     
     
       38. A method of adding at least two new members to a conference, the conference being associated with a list of participating members, the method comprising:
 receiving a join message, wherein the join message includes a destination conference identifier and a calling conference identifier;   obtaining a list of at least two new members to be added to the conference;   merging the list of at least two new members with the list of participating members; and   establishing a media connection with the at least two new members.   
     
     
       39. The method of claim 38 wherein the conference comprises a teleconference. 
     
     
       40. The method of claim 38 wherein the conference comprises a video conference. 
     
     
       41. The method of claim 38, wherein the join message includes the list of at least two new members. 
     
     
       42. The method of claim 38, wherein the list of at least two new members comprises a subset of members of a second conference, wherein the subset comprises only members of the second conference that agree to share the conference media data with new conference members. 
     
     
       43. An apparatus for adding at least two new members to a conference, the conference being associated with a list of participating members, the method comprising:
 a circuit for receiving a join message, wherein the join message includes a destination conference identifier and a calling conference identifier;   a circuit for obtaining a list of at least two new members to be added to the conference;   a circuit for merging the list of at least two new members with the list of participating members; and   a circuit for establishing a media connection with the at least two new members.   
     
     
       44. The apparatus of claim 43 wherein the conference comprises a teleconference. 
     
     
       45. The apparatus of claim 43 wherein the conference comprises a video conference. 
     
     
       46. A method of adding at least two new members to a conference, the conference being associated with a list of participating members, the method comprising:
 transmitting a first message requesting to join the conference, wherein the first message includes a destination conference identifier and a calling conference identifier;   receiving an acknowledgement message;   receiving the list of participating members; and   transmitting a second message to establish media connections with the participating members.   
     
     
       47. The method of claim 46 wherein the conference comprises a teleconference. 
     
     
       48. The method of claim 46 wherein the conference comprises a video conference. 
     
     
       49. The method of claim 46, further comprising:
 responsive to receiving at least one third message indicating that one or more participating members can receive multicast transmissions, causing a multicast transmission.   
     
     
       50. The method of claim 46, wherein the acknowledgment message includes a response code. 
     
     
       51. The method of claim 46, further comprising:
 responsive to less than a requisite number of participating members receiving a multicast transmission, causing the multicast transmission to be terminated.   
     
     
       52. The method of claim 46, further comprising:
 determining whether a single communication medium supports multicast transmissions to the participating members.   
     
     
       53. The method of claim 46, wherein the first message includes a list of at least two new members to be added to the conference. 
     
     
       54. The method of claim 53, wherein the list of at least two new members comprises a subset of members of a second conference, wherein the subset comprises only members of the second conference that agree to share the conference media data with new conference members. 
     
     
       55. An apparatus for adding at least two new members to a conference, the conference being associated with a list of participating members, the apparatus comprising:
 a first circuit for transmitting a first message requesting to join the conference, wherein the first message includes a destination conference identifier and a calling conference identifier:   a second circuit for receiving an acknowledgement message;   a third circuit for receiving the list of participating members; and   a fourth circuit for transmitting a second message to establish media connections with the participating members.   
     
     
       56. The apparatus of claim 55 wherein the conference comprises a teleconference. 
     
     
       57. The apparatus of claim 55 wherein the conference comprises a video conference. 
     
     
       58. The apparatus of claim 55, wherein the second circuit is further configured to determine whether one or more participating members can receive multicast transmissions. 
     
     
       59. The apparatus of claim 55, wherein the acknowledgment message includes a response code. 
     
     
       60. The apparatus of claim 55, further comprising: a fifth circuit for transmitting a third message to terminate the media connections with the participating members, responsive to the list of participating members being less than a requisite number. 
     
     
       61. The apparatus of claim 55, further comprising: a fifth circuit for determining whether a single communication medium coupled to the participating members supports multicast transmissions.