Abstract: Client-server conference and user seeking is disclosed. In one embodiment, a system includes at least one server of a first type, a server of a second type, and a client. Each of the at least one server of the first type maintains at least one conference. The server of the second type stores a server list of the servers of the first type. The client queries this latter server to obtain the server list, and then is able to query each server on the list to learn of the conferences maintained by these servers. User lists may also be maintained by either the first and/or second server types, for querying by the client.

Abstract: A method and system for dynamically altering the transmission settings of one or more computing devices engaged in a real-time communication session is presented. The devices exchange meaningful and dummy control packets according to a standard control protocol. The approximate bandwidth available on the network is then calculated based on the difference in arrival times between at least one of the dummy control packets and at least one of the meaningful control packets. Once the approximate bandwidth available on the network is computed, the one or more devices adjust outgoing audio and video data streams using a quality control mechanism. The quality control mechanism enables the one or more devices to transmit data in a way that maximizes the user experience during the real-time communication session.

Abstract: A technique for reducing information reception delays is provided. The technique reduces delays that may be caused by protocols that guarantee order and delivery, such as TCP/IP. The technique creates multiple connections between a sender and recipient computing devices and sends messages from the sender to the recipient on the multiple corrections redundantly. The recipient can then use the first arriving message and ignore the subsequently arriving redundant messages. The recipient can also wait for a period of time before determining which of the arrived messages to use. The technique may dynamically add connections if messages are not consistently received in a timely manner on multiple connections. Conversely, the technique may remove connections if messages are consistently received in a timely manner on multiple connections. The technique can accordingly be used with applications that are intolerant of data reception delays such as Voice over IP, real-time streaming audio, or real-time streaming video.

Abstract: Technology to facilitate collaborative communications is provided. The technology may include, for example, operations directed to publishing and subscribing services. The operations may facilitate publication of data derived from multiple data types as well as subscription to selectively filtered views of published data. Published data may be updated, and notification of various events and services may be provided.

Abstract: An architecture for developing new media activities and deploying the newly developed activities in a reusable collaboration session is provided. The architecture comprises a base collaboration session, a base activity class, and a well defined contract between the base activity class and the collaboration session. The base collaboration session provides signaling plane functionality, including session management services and media negotiation services. The base activity class provides the base class support needed to build or develop activities derived from the base activity class. The well defined contract enables the base activity class and the base collaboration session to work together to hide the details of the signaling plane from the derived activities.

Abstract: A technique for reducing information reception delays is provided. The technique reduces delays that may be caused by protocols that guarantee order and delivery, such as TCP/IP. The technique creates multiple connections between a sender and recipient computing devices and sends messages from the sender to the recipient on the multiple corrections redundantly. The recipient can then use the first arriving message and ignore the subsequently arriving redundant messages. The recipient can also wait for a period of time before determining which of the arrived messages to use. The technique may dynamically add connections if messages are not consistently received in a timely manner on multiple connections. Conversely, the technique may remove connections if messages are consistently received in a timely manner on multiple connections. The technique can accordingly be used with applications that are intolerant of data reception delays such as Voice over IP, real-time streaming audio, or real-time streaming video.

Abstract: A technique for reducing information reception delays is provided. The technique reduces delays that may be caused by protocols that guarantee order and delivery, such as TCP/IP. The technique creates multiple connections between a sender and recipient computing devices and sends messages from the sender to the recipient on the multiple corrections redundantly. The recipient can then use the first arriving message and ignore the subsequently arriving redundant messages. The recipient can also wait for a period of time before determining which of the arrived messages to use. The technique may dynamically add connections if messages are not consistently received in a timely manner on multiple connections. Conversely, the technique may remove connections if messages are consistently received in a timely manner on multiple connections. The technique can accordingly be used with applications that are intolerant of data reception delays such as Voice over IP, real-time streaming audio, or real-time streaming video.

Abstract: Computers, particularly personal computers, have become everyday communications devices, nearly as common as telephones and televisions. A big reason for this is the expansion of computer networks, such as the internet, which allow sending and receiving information, including audio and video information, from one computer to one or more other computers. Communicating audio and video information between computers can be problematic because users have to wait for the information to be fully downloaded before viewing or hearing it and because different computers sometimes communicate using incompatible communications protocols, which prevents comprehension. Accordingly, the inventors devised new methods, software, and computer systems that support interactive data streaming (real-time exchange of multimedia data) and full-duplex communications, for example, network conferencing, using more than one communications protocol.

Abstract: Various strategies for rate/quality control and loss resiliency in an audio codec are described. The various strategies can be used in combination or independently. For example, a real-time speech codec uses intra frame coding/decoding, adaptive multi-mode forward error correction [“FEC”], and rate/quality control techniques. Intra frames help a decoder recover quickly from packet losses, while compression efficiency is still emphasized with predicted frames. Various strategies for inserting intra frames and signaling intra/predicted frames are described. With the adaptive multi-mode FEC, an encoder adaptively selects between multiple modes to efficiently and quickly provide a level of FEC that takes into account the bandwidth currently available for FEC. The FEC information itself may be predictively encoded and decoded relative to primary encoded information. Various rate/quality and FEC control strategies allow additional adaptation to available bandwidth and network conditions.

Abstract: An architecture for an extensible real-time collaboration system is provided. The architecture presents a unified application program interface for writing application programs that use communications protocols. The architecture has activity objects, endpoint objects, and multiple media stacks. These objects may use various communications protocols, such as Session Initiation Protocol or Real-Time Transport Protocol to send and receive messages. The activity objects, endpoint objects, and multiple media stacks may each have one or more APIs that an application developer can use to access or provide collaboration-related functionality. These objects map the API to the underlying implementation provided by other objects. Using the activity objects enables a developer to provide less application logic than would otherwise be necessary to provide complex collaboration services.

Abstract: Computers, particularly personal computers, have become everyday communications devices, nearly as common as telephones and televisions. A big reason for this is the expansion of computer networks, such as the Internet, which allow sending and receiving information, including audio and video information, from one computer to one or more other computers. Communicating audio and video information between computers can be problematic because users have to wait for the information to be fully downloaded before viewing or hearing it and because different computers sometimes communicate using incompatible communications protocols, which prevents comprehension. Accordingly, the inventors devised new methods, software, and computer systems that support interactive data streaming (real-time exchange of multimedia data) and full-duplex communications, for example, network conferencing, using more than one communications protocol.

Abstract: A method and system for dynamically altering the transmission settings of one or more computing devices engaged in a real-time communication session is presented. The devices exchange meaningful and dummy control packets according to a standard control protocol. The approximate bandwidth available on the network is then calculated based on the difference in arrival times between at least one of the dummy control packets and at least one of the meaningful control packets. Once the approximate bandwidth available on the network is computed, the one or more devices adjust outgoing audio and video data streams using a quality control mechanism. The quality control mechanism enables the one or more devices to transmit data in a way that maximizes the user experience during the real-time communication session.

Abstract: A method and system is provided to integrate the Kerberos security mechanism into the message flow of the signaling operation under the Session Initiation Protocol to allow a SIP client and a SIP proxy to authenticate each other. When the SIP proxy receives an request message, such an INVITE request, from the SIP client, it responds with a challenge message indicating that authentication based on Kerberos is required. In response, the SIP client sends a second request message with a proxy authorization header containing authentication data, including a Kerberos server ticket for the Proxy, to allow the proxy to authenticate the client's user.

Abstract: Client-server conference and user seeking is disclosed. In one embodiment, a system includes at least one server of a first type, a server of a second type, and a client. Each of the at least one server of the first type maintains at least one conference. The server of the second type stores a server list of the servers of the first type. The client queries this latter server to obtain the server list, and then is able to query each server on the list to learn of the conferences maintained by these servers. User lists may also be maintained by either the first and/or second server types, for querying by the client.