Abstract: Techniques for a mixed audio conference are described. An apparatus may comprise an audio video multipoint control unit to mix call information from multiple call connections established over a packet-switched network for a conference call. The apparatus may comprise a telephony gateway communicatively coupled to the audio video multipoint control unit. The telephony gateway may establish a bridge connection with a conference bridge servicing a call connection over a circuit-switched network, the telephony gateway to translate call information from the call connection for use by the audio video multipoint control unit. Other embodiments are described and claimed.

Abstract: A method, system, and architecture for providing a conference system that effectively achieves high availability conferencing is provided. The conference system architecture provides a conference system that comprises a set of stateless conference servers and a shared conference store to provide highly available conferencing to its users. The conference servers serve (host) conferences (meetings) that allow users to conduct distributed conferences. Each conference server generally performs conference provisioning operations and conference control operations. The shared conference store provides for the storage of conference state information, thus allowing the conference servers in the conference server pool to be stateless by maintaining conference state information on the shared conference store. A stateless conference server may also locally maintain, for example, in cache memory, some of the conference state information that is maintained on the shared conference store.

Abstract: A method, system, and architecture for detecting MCU failures is provided. The conference system detects the failure of MCUs that have been allocated to provide shared conference resources to conferences that are being hosted by the conference system. The conference system utilizes the sending and receiving of “heartbeat” messages between the MCUs and the conference server pool to detect failed MCUs. Upon detecting the failure of an MCU, the conference system performs a “rollover” of the conferences which were being serviced by the failed MCU to another available MCU. The conference system may then identify the clients which were connected to the failed MCU and notifies the clients that an MCU rollover has occurred and a new (replacement) MCU is available in order that these clients can reconnect and reestablish their media sessions.

Abstract: A method and system for handling otherwise rejectable messages (e.g., out-of-order messages) sent using a communication protocol (e.g., SIP) is provided. When a message is received at a protocol layer of a client system, the message (or at least its information) is passed to a higher layer (e.g., an application layer) even if it is otherwise rejectable at the protocol layer. In this way, the protocol layer provides an application layer with the option of determining whether to discard the otherwise rejectable message. In some embodiments, the protocol layer may automatically acknowledge acceptance of the message, while in other embodiments, the protocol layer may wait to receive an indication from the higher layer to determine whether to acknowledge or negatively acknowledge acceptance of the message.

Abstract: A method and system for combining SIP requests with SIP responses is provided. When a server receives a request from a client, a message combining system of the server sends a response to the request that includes the content of a request that the server would normally send to the client in a separate request. The message combining system of the server composes a response as it would normally and adds the content of the subsequent request to the response. The server then sends the combined response and request to the client. When the client receives the response, it retrieves and processes the combined request.

Abstract: A synchronization system establishes a session between a client end point and a server end point via an intermediary server of a server pool. When messages sent from the client end point to the server end point are received at the server pool and the intermediary server is unavailable, the messages are routed to a new intermediary server. The end points, however, may be unsynchronized as a result of the unavailability. The new intermediary server can detect that it is a new intermediary server for the session and assumes that the server end point and the client end point may be unsynchronized because of the unavailability. The new intermediary server then notifies the client end point that it may need to re-synchronize with the server end point.

Abstract: A facility for generating and using a unique identifier as a key to identify a unique user agent instance among multiple user agents of the same user is provided. The facility generates an identifier for a first user agent instance, which is an instance of a user in an application instance. The facility uses the identifier for a registration of the first user agent instance with a logical server, and associates the identifier with the first user agent instance and the logical server registration pair. The facility then uses the identifier for a subsequent registration of the first user agent instance with the logical server.