摘要:
The media dependent module provides an interface between an upper-level conferencing driver (e.g., a data-link manager) of the conferencing system and a lower-level communications driver of the conferencing system to isolate the conferencing driver from the communications driver, where the media dependent module is dependent upon hardware of the communications driver. The media dependent module is adapted to perform a plurality of functions called by the conferencing driver. The media dependent module has a connection state machine. In a preferred embodiment, the communications driver is a communications stack that conforms to one of the NetBIOS, IPX, POTS Modem, and TAPI transport standards. The conferencing system may have multiple media dependent modules, each of which provides an interface between the data-link manager and a communications stack that conforms to a different transport standard.
摘要:
A server/client for a network-based multicast system has a media services manager and one or more media service providers. When functioning as a server, the media service providers receive data corresponding to a channel having one or more related data streams, where each media service provider receives data corresponding to a data stream of the channel. In the server, the media services manager receives the data from the media service providers and transmits the data to the network. When functioning as a client, the media services manager receives data from the network for a selected channel having one or more related data streams. In the client, the media service providers receive and play the data from the media services manager, where each media service provider receives and plays data corresponding to a data stream of the channel. In a preferred embodiment, a channel has logically related audio, video, and/or text data streams.
摘要:
A distributed protocol for allocation of multicast addresses. A first node of a network sends an address request message identifying (1) a requested in multicast address, and (2) a multicast group identifier to which the requestor belongs. The request is in multicast on a network address reserved for address resolution. All other nodes of the network monitor the reserved network address for address request messages. If a second node receiving the address request message has already allocated the requested multicast address, then the second node sends an acknowledgment message identifying (1) the already allocated in multicast address, and (2) the multicast group for which the address has been allocated. This acknowledgment is transmitted on the same reserved network address on which the address request was sent. The first node, monitoring the reserved network address, receives the acknowledgment message. If the multicast group identified in the acknowledgment message matches the multicast group to which the first node belongs, then the first node also allocates the requested network address. If the multicast group identified in the acknowledgment message does not match the multicast group to which the first node belongs, then the first node abandons the requested network address. If the first node does not receive an acknowledgment message in response to any number of address request messages repeated for the same requested multicast address, then the first node either (1) allocates the requested network address, or (2) abandons the requested network address, if the node is not the first member of a multicast group to request allocation of the address. If address allocation succeeds, then the first node uses the allocated network address for multicasting. If address allocation fails, then the first node is free to select a different multicast address to request.
摘要:
A user interface is displayed on a computer system capable of processing one or more data streams. The user interface has one or more displayed representations, where each of the displayed representations corresponds to one of the data streams. A user of the computer system selectively adjusts the processing of each of the data streams using the corresponding displayed representation of the user interface. In a preferred embodiment, in which the computer system is a system for multicasting audio, video, and/or text data streams, the user interface has a video window for displaying the video stream, a set of audio controls for controlling the play of the audio stream, and a text reader bar for displaying the text stream.