Mechanisms for efficient transmission management are provided for multiparty, multimedia communications by constructing a logical ring structure from logical point-to-point connections between multiple nodes participating in a communication. Data and control information are unbundled in the communication by providing several different higher level protocols or applications, called "user entities," at each node and enabling uninhibited data transfer between corresponding user entities of the different nodes via virtual rings built on top of the logical ring. A mechanism preferably is provided for a user entity to selectively accept or reject a packet on the basis of the importance of the information contained in the packet.
A ring is routed through a subset of nodes of a communication network by first providing a branch-decomposition having a pattern relating to separations of the network. The branch-decomposition can be performed using internal two-separations, internal three-separations, eigenvector separations and pushing. If the branch-decomposition has a branch-width less than or equal to a predetermined constant value, then the branch-decomposition is used to determine costs associated with portions of the ring passing through separations of the network by examining matchings corresponding to edges of the branch-decomposition and selecting a lowest cost ring by examining the matchings and choosing a lowest cost set of matchings containing the subset of nodes. The branch-decomposition can be provided once for a fixed network and then costs can be determined and the ring route selected repeatedly for different subsets of ring nodes and different edge costs. The edge costs can be negative.
Methods, apparatus and computer products are provided for allocating network resources for data transport between a source network node and a destination network node by selecting a transport mechanism from a plurality of transport mechanisms based upon a prediction of the cost of the utilization of the transport mechanism so as to provide the transport mechanism having the lowest predicted cost.
A method to enable unique identification of serial devices having a common bus for communication with a bus master includes the step of serially clocking a mask value through a plurality of serial devices until each serial device stores a corresponding portion of the mask value. Each serial device responds to a subsequent command only if enabled by the corresponding portion of the mask value. Another method includes the step of initializing a plurality of serial devices to one of a first mode and a second mode. If the plurality of devices are in the second mode, a mask value is serially clocked through the plurality of serial devices until each serial device stores a corresponding portion of the mask value. When in the first mode every serial device responds to a subsequent command. When in the second mode, only serial devices enabled by the corresponding portion of the mask value respond to the command. An apparatus includes a plurality of serial devices coupled to a bus master by a bus. The bus master clocks a mask value through the plurality of serial devices until each serial device stores a portion of the mask value. Each of the plurality of serial devices responds to a subsequent bus master issued command only if enabled by the corresponding portion of the mask value. In various embodiments, the plurality of serial devices may be a heterogeneous or homogeneous combination of devices. In one embodiment, at least one of the devices comprises a subscriber line interface circuit.
A method includes the step of serially clocking a mask value through a plurality of subscriber line interface circuits (SLICs) until each SLIC stores a corresponding portion of the mask value, and serially communicating a command to the plurality of SLICs. Each SLIC responds to the command only if enabled by the corresponding portion of the mask value.
The present invention relates to a network system capable of easily correcting communication terminal administration data identically in a plurality of nodes (i.e. store and forward machines) without specially requiring installation of any additional hardware. The network system comprises at least two nodes each administrating a plurality of communication terminals. Each of the nodes has a memory device memorizing not only data of its own administrating communication terminals but data of other communication terminals administrated by other nodes. And further, each node is effected to notify any change occurring in its own administrating communication terminals to other nodes in the network system.
