Large-scale, fault-tolerant audio conferencing in a purely packet-switched network

Abstract

A method of large-scale fault-tolerant audio conferencing in an audio conferencing system using a purely packet-switched network. An endpoint places a call to a conference gatekeeper indicating an audio conference. The conference gatekeeper determines whether the call contains sufficient information to establish the audio conference. If there is insufficient information, the endpoint is connected to an IVR server that obtains sufficient information from the endpoint. Either way, a CACS selects an MCU hosting or that will host the audio conference. The CACS then responds to the endpoint with routing instructions indicating the selected MCU and the endpoint connects or transfers to the selected MCU. The MCU mixes input from all endpoints in the audio conference to form a voice stream, which is then returned to each endpoint in the audio conference. Audio conference participants can dial-out from the MCU to bring additional participants into the audio conference. Once established, the audio conference supports full service audio conferencing. In addition, dynamic routing permits an operator to service multiple MCUs, and an audio conference participant and/or an entire audio conference to be moved between MCUs. The audio conference can also be broadcast from a streaming protocol server to passive participants.

We claim:  
     
         1 . A method of large-scale fault-tolerant audio conferencing in a purely packet-switched audio conferencing system, said method comprising the steps of: 
 placing a call from an endpoint to a conference gatekeeper, said call indicating an audio conference;    querying a CACS from said conference gatekeeper for routing instructions for said audio conference;    determining in said CACS whether said audio conference is active;    selecting in said CACS an MCU to host said audio conference when said audio conference is inactive;    selecting in said CACS an MCU hosting said audio conference when said audio conference is active;    responding from said CACS to said endpoint with said queried routing instructions, said queried routing instructions indicating said selected MCU;    connecting said endpoint to said selected MCU;    mixing input from all endpoints in said audio conference to form a voice stream; and    returning said voice stream to each endpoint in said audio conference.    
     
     
         2 . The method of  claim 1  wherein the step of placing a call links said endpoint to said conference gatekeeper through a gatekeeper cloud.  
     
     
         3 . The method of  claim 1  wherein the step of placing a call links said endpoint to said conference gatekeeper through said packet-switched network.  
     
     
         4 . The method of  claim 1  wherein the routing instructions include at least an LCF signal indicating the selected MCU.  
     
     
         5 . The method of  claim 1  wherein the call includes at least an LRQ signal.  
     
     
         6 . The method of  claim 1  further comprising the steps of: 
 determining in said CACS whether the call from said endpoint contains adequate information to establish said audio conference;  
 responding from said CACS to said endpoint with routing instructions to an IVR server when there is inadequate information to establish said audio conference;  
 connecting said endpoint to said IVR server when there is inadequate information to route said call;  
 gathering in said IVR server, after connecting said endpoint to said IVR server, adequate information to establish said audio conference; and  
 transferring said endpoint from said IVR server to said selected MCU after said IVR server gathers said adequate information.  
 
     
     
         7 . The method of  claim 1  further having a dial-out method comprising the steps of: 
 initiating a call request from said selected MCU to said conference gatekeeper, said call request indicating an additional endpoint;  
 transmitting an LRQ from the conference gatekeeper to the gatekeeper cloud;  
 returning a destination address to said conference gatekeeper from said gatekeeper cloud, said destination address corresponding to said additional endpoint;  
 forwarding said destination address from said conference gatekeeper to said selected MCU;  
 establishing a point-to-point call from said MCU to said additional endpoint based on said destination address, thereby bringing said additional endpoint into said audio conference.  
 
     
     
         8 . The method of  claim 1  further supporting full service audio conferencing using a reservation system and a call agent.  
     
     
         9 . The method of  claim 8  wherein the reservation system and the call agent are tightly integrated.  
     
     
         10 . The method of  claim 8  wherein the reservation system and the call agent are loosely integrated.  
     
     
         11 . The method of  claim 1  wherein said selected MCU is selected from an MCU pool.  
     
     
         12 . The method of  claim 1  further including the step of dynamically routing an operator voice path to service multiple MCUs.  
     
     
         13 . The method of  claim 1  further including the step of renegotiating the destination of a voice path to move an audio conference participant from said selected MCU to a second MCU.  
     
     
         14 . The method of  claim 1  further including the step of moving said audio conference from said selected MCU to a second MCU.  
     
     
         15 . The method of  claim 1  further including the steps of: 
 providing said audio conference to a streaming protocol server from said selected MCU;  
 connecting a passive participant to said streaming protocol server; and  
 broadcasting said audio conference from said streaming protocol server to a passive participant.  
 
     
     
         16 . A large-scale fault-tolerant purely packet-switched audio conferencing method, said method comprising the steps of: 
 establishing an audio conference by: 
 connecting an endpoint to a conference gatekeeper, said endpoint indicating an audio conference;  
 querying a CACS from said conference gatekeeper for routing instructions for said audio conference;  
 determining in said CACS the status of said audio conference;  
 selecting in said CACS an MCU to host said audio conference when said status of said audio conference is inactive;  
 selecting in said CACS an MCU hosting said audio conference when said status of said audio conference is active;  
 responding from said CACS to said endpoint with said queried routing instructions, said queried routing instructions indicating said selected MCU;  
 connecting said endpoint to said audio conference through said selected MCU;  
 mixing input from all endpoints in said audio conference to form a voice stream;  
 returning said voice stream to each endpoint in said audio conference; and  
   dialing out from the audio conference when said status of said audio conference is active to connect additional endpoints to the audio conference by: 
 initiating in the endpoint connected to said audio conference a call request from said selected MCU to said conference gatekeeper, said call request indicating said additional endpoint;  
 transmitting an LRQ from the conference gatekeeper to the gatekeeper cloud;  
 returning a destination address to said conference gatekeeper from said gatekeeper cloud, said destination address corresponding to said additional endpoint;  
 forwarding said destination address from said conference gatekeeper to said selected MCU;  
 establishing a point-to-point call from said MCU to said additional endpoint based on said destination address, thereby bringing said additional endpoint into said audio conference.  
   
     
     
         17 . The method of  claim 16  further comprising the steps of: 
 determining in said CACS whether the call from said endpoint contains adequate information to establish said audio conference;  
 responding from said CACS to said endpoint with routing instructions to an IVR server when there is inadequate information to establish said audio conference;  
 connecting said endpoint to said IVR server when there is inadequate information to route said call;  
 gathering in said IVR server, after connecting said endpoint to said IVR server, adequate information to establish said audio conference; and  
 transferring said endpoint from said IVR server to said selected MCU after said IVR server gathers said adequate information.  
 
     
     
         18 . The method of  claim 16  further supporting full service audio conferencing using a reservation system and a call agent.  
     
     
         19 . The method of  claim 16  wherein said selected MCU is selected from an MCU pool.  
     
     
         20 . The method of  claim 16  further including the step of dynamically routing an operator voice path to service multiple MCUs.  
     
     
         21 . The method of  claim 16  further including the step of renegotiating the destination of a voice path to move an audio conference participant from said selected MCU to a second MCU.  
     
     
         22 . The method of  claim 16  further including the step of moving said audio conference from said selected MCU to a second MCU.  
     
     
         23 . The method of  claim 16  further including the steps of: 
 providing said audio conference to a streaming protocol server from said selected MCU;  
 connecting a passive participant to said streaming protocol server; and  
 broadcasting said audio conference from said streaming protocol server to a passive participant.  
 
     
     
         24 . A large-scale fault-tolerant audio conferencing method over a purely packet-switched network, said method comprising the steps of: 
 initiating a call from an endpoint to a conference gatekeeper;    querying a CACS from said conference gatekeeper for routing instructions for an audio conference;    determining in said CACS whether the call from said endpoint contains adequate information to establish said audio conference;    responding from said CACS to said endpoint with routing instructions to an IVR server when there is inadequate information to establish said audio conference;    connecting said endpoint to said IVR server when there is inadequate information to route said call and: 
 gathering in said IVR server adequate information to establish said audio conference; and  
 transferring said adequate information to the CACS;  
   determining in said CACS the status of said audio conference;    selecting in said CACS an MCU to host said audio conference when said status of said audio conference is inactive;    selecting in said CACS an MCU hosting said audio conference when said status of said audio conference is active;    responding from said CACS to said endpoint with said queried routing instructions, said queried routing instructions indicating said selected MCU;    transferring said endpoint from said IVR server to said audio conference at said selected MCU when there is inadequate information to route the call; and    connecting said endpoint to said audio conference at said MCU when there is adequate information to route the call.    
     
     
         25 . The method of  claim 24  further supporting full service audio conferencing using a reservation system and a call agent.  
     
     
         26 . The method of  claim 24  wherein said selected MCU is selected from an MCU pool.  
     
     
         27 . The method of  claim 24  further including the step of dynamically routing an operator voice path to service multiple MCUs.  
     
     
         28 . The method of  claim 24  further including the step of renegotiating the destination of a voice path to move an audio conference participant from said selected MCU to a second MCU.  
     
     
         29 . The method of  claim 24  further including the step of moving said audio conference from said selected MCU to a second MCU.  
     
     
         30 . The method of  claim 24  further including the steps of: 
 providing said audio conference to a streaming protocol server from said selected MCU;  
 connecting a passive participant to said streaming protocol server; and  
 broadcasting said audio conference from said streaming protocol server to a passive participant.  
 
     
     
         31 . A large-scale fault-tolerant audio conferencing method in a purely packet-switched network, said method comprising the steps of: 
 initiating a call from an endpoint to a conference gatekeeper in a gatekeeper cloud;    querying a CACS from said conference gatekeeper for routing instructions for an audio conference;    determining in said CACS whether the call from said endpoint contains adequate information to establish said audio conference;    responding from said CACS to said endpoint with routing instructions to an IVR server when there is inadequate information to establish said audio conference;    connecting said endpoint to said IVR server when there is inadequate information to route said call and: 
 gathering in said IVR server adequate information to establish said audio conference; and  
 transferring said adequate information to the CACS;  
   determining in said CACS the status of said audio conference;    selecting in said CACS a conference MCU from an MCU pool, said conference MCU hosting said audio conference when said status of said audio conference is inactive;    selecting in said CACS a conference MCU from an MCU pool, said conference MCU hosting said audio conference when said status of said audio conference is active;    responding from said CACS to said endpoint with said queried routing instructions, said queried routing instructions indicating said selected MCU;    transferring said endpoint from said IVR server to said audio conference at said selected conference MCU when there is inadequate information to route the call;    connecting said endpoint to said audio conference at said conference MCU when there is adequate information to route the call, once said endpoint is connected to said audio conference, said audio conference: 
 supporting full service conferencing in said audio conference to said endpoint with a reservation system and a call agent;  
 supporting dynamically routed audio signals within said packet-switched network;  
 supporting passive participants in said packet-switched network  
 supporting dial out from said audio conference to an additional endpoint.