Abstract: One or more validation keys are embedded in a data stream at a server. A client requests the data stream from the server. The server sends the data stream to the client. The client receives the data stream, and samples the data stream to detect one or more validation keys.

Abstract: The audio manager provides an interface between one or more upper-level conferencing drivers of the conferencing system and one or more lower-level audio drivers of the conferencing system to isolate the conferencing drivers from the audio drivers. The audio manager is adapted to perform a plurality of functions called by the conferencing drivers. The audio manager comprises a local audio stream state machine and a remote audio stream state machine.

Abstract: Conferencing nodes transmit messages back and forth to negotiate characteristics for their conferencing session. The messages identify different sets of conferencing capabilities supported by the conferencing nodes. A first node transmits a request to a second node, wherein the request identifies a first set of conferencing capabilities of the first node. The second node transmits a response to the first node, wherein the response identifies a second set of conferencing capabilities of the second node and the second set is a subset of the first set. The first node and second node conduct conferencing based on the second set.

Abstract: Nodes of a computer-based teleconferencing network may be able to encode and decode video signals using different video compression/decompression algorithms with different parameters. In order to conduct a video teleconference between two (or more) such nodes, the nodes must first agree on what video algorithms to use. In the present invention, video capabilities are negotiated between nodes, where each node uses a table that identify one or more sets of video capabilities for that node. After video capabilities have been successfully negotiated, the video conferencing can proceed using the negotiated capabilities. Negotiated video capabilities may include algorithms, frame rate, frame resolution, bit rate, and bitstream format.