Abstract: Hubs 11–14 are circularly connected with each other. The hubs 11 and 12 are supplied with electric power from the power source 1 and the hubs 13 and 14 are supplied with electric power from the power source 2. Each of the terminals 7–10 has two ports each of which is connected to the hub supplied from different power source.

Abstract: A self-routing multicast switching network composed of bicast cells interconnected as a bit-permuting network and, in particular, as a banyan-type network, and the concomitant general self-routing control mechanism for multicasting the packets over such networks. The self-routing mechanism includes the approach of determining the routing tag of a packet from the guide of the network and the destination addresses of the packet, and accomplishes the self-routing of the packets by the sorting of the packets.

Abstract: A system includes a first integrated circuit device and a second integrated circuit device. The first device transmits a data sequence to the second integrated circuit device, and the second device samples the data sequence to produce receiver data. The second device then transmits the receiver data back to the first device. Within the first integrated circuit device, a comparison between the data sequence and the receiver data is performed, and based on the comparison, the first device generates information representative of a calibrated timing offset. The first device uses the information representative of the calibrated timing offset to adjust timing associated with transferring write data from the first integrated circuit to the second integrated circuit.

Abstract: Broadband switching including the implementation of and control over a massive sub-microsecond switching fabric. To effect the attributes of the switching fabric, conditionally nonblocking components are used a building-blocks in an interconnection network which is recursively constructed. The properties of the interconnection network are preserved during each recursion to thereby configure the massive switching fabric from scalable circuitry.

Abstract: The present invention provides an application specific integrated circuit and a method of operation thereof. In one advantageous embodiment, the application specific integrated circuit includes a programmable logic core having an array of dynamically configurable arithmetic logic units. This particular embodiment further includes a network interface subsystem that includes a media access controller. The network interface is configured to employ a first portion of the programmable logic core that interfaces with the media access controller and that is configurable to process control data. This embodiment further includes a data transmission subsystem associated with a memory device, and configured to employ a second portion of the programmable logic core that stores received data from the network interface subsystem to the memory device and sends transmission data from the memory device to the network interface subsystem in response to an instruction from a host system.

Abstract: A Digital Subscriber Line (xDSL) is used to connect Customer Premises Equipment (CPE) to a telecommunications network. The Customer Premises Equipment generates both Constant Bit-Rate (CBR) and Variable Bit-Rate (VBR) Packets. Each Frame of Packets from the Customer Premises Equipment is used to transmit up to a limited amount of CBR data, and VBR data is used, if available, to fill up the Frame. The limit on the amount of CBR data can be dynamically adjusted according to the need of the CPE. Similarly, and importantly, a limit on CBR data to the CPE can be adjusted dynamicaly according to the need for transmission of CBR data to the CPE. Advantageously, a guaranteed rate of transmission of CBR data can be maintained, even in the face of a flood of VBR traffic. Advantageously, this arrangement improves the quality of service on CBR traffic, such as Voice, and subject to the limit imposed by CBR traffic, allows a maximum amount of VBR traffic to be transmitted.

Abstract: An improved mechanism for analysing connection establishment/teardown process or identifying failure points (i.e. nodes) in a PNNI network through the use of a novel debug IE (information element) that is propagated along the communication path for a given connection to activate diagnostic functions on targeted switching devices. The mechanism comprises a method that is initiated by embedding a debug information element (IE) in a data packet that is propagated to various switching devices (the nodes) along the communication path. The debug IE is encoded such that it will be recognized by selected switching devices along the path, but ignored by other non-selected switching devices. Further encoding identifies targeted switching devices that are suspected to be possible failure points to confirm that they are functioning properly.

Abstract: A dynamic bandwidth assignment system includes a network unit for carrying out cell slot assignment, and a network termination for transmitting cells to the network unit by means of cell slots assigned by the network unit. When the number of consecutive valid cells the network unit receives from the network terminations exceeds a predetermined threshold value, the network unit increases the number of the cell slots to be assigned to the network termination. The system can solve a problem of a conventional system in that it is unavoidable that a cell transfer delay and a bursting tendency of cells are statistically increased.

Abstract: A method and apparatus for forming and processing an MPEG transport stream such that programs may be inserted into, or deleted from, the MPEG transport stream without significant retiming operations.

Abstract: In a communication network that includes a plurality of nodes interconnected by links, a method for routing a data flow includes receiving a request to allocate one or more resources in the network so as to carry the data flow between first and second ones of the nodes over one of a plurality of paths therebetween, each such path including a respective sequence of the links. For the links included in each of the paths, respective levels of use of the requested resources due to communications in process over the network are determined. The path that is to carry the data flow is selected responsive to the determined levels of use of the requested resources on the links included in each of the paths.

Abstract: The invention provides a convenient and expandable method for transmitting one or more loss rate statistics determined in a distributed manner from a multicast distribution tree to a source computer. First, the loss rate statistics are collected in a distributed manner from target receiver stations, and from routers in the multicast distribution tree. Second, there is a distributed calculation of statistics on loss rate by routers in the multicast distribution tree. Third, there is transportation of the loss rate statistics back to the source computer in reverse along the multicast distribution tree. For example, congestion information is collected by routers, and the congestion information is sent upstream to the multicast source station in fields of NAK messages. A router may receive a NAK packet in transit from an intended destination station to a source station, the NAK packet indicating loss of a data packet.

Abstract: Methods of evaluating access to Virtual Private Networks (VPNs) from alternate access connections and for improving access to VPNs from alternate access connections such as ISPs. The methods include downloading a set of tests through a network backbone to simulate access to the VPN from the alternate access connection and comparing the results of the test to benchmarks for the test of access to the VPN from leased lines and modems. By obtaining comparisons of the tests and the benchmarks, it is possible to determine the throughput of data through the VPN and tell the customer how its access connections are affecting, among other things, the raw data throughput. This allows the customer and/or the network service provider to adjust the access connections to improve communications with the VPN.

Abstract: Link failure messages are sent through a network to accelerate convergence of routing information after a network fault. The link failure messages reduce the oscillations in routing information stored by routers, which otherwise can cause significant problems, including intermittent loss of network connectivity as well as increased packet loss and latency. For example, the link failure messages reduce the time that a network using a path vector routing protocol, such as the Border Gateway Protocol (BGP), takes to converge to a stable state. More particularly, upon detecting a network fault, a router generates link failure information to identify the specific link that has failed. In some types of systems, the router communicates the link failure information to neighboring routers as well as a conventional update message withdrawing any unavailable routes. Once other routers receive the link failure information, the routers do not attempt to use routes that include the failed link.

Abstract: The present invention relates to label switch networks and allows for reducing the processing cost and processing time required at each node when various services are performed with respect to traffic engineering in the label switch networks including a multi-protocol label switching (MPLS) network. In a label switch network system a first node that is disposed at the ingress of the label switch network transfers IP packets corresponding to IP flows based on labels, and that selects and sets up layer 2 paths for transferring the IP packets with reference to header or payload information of the IP packets. A plurality of second nodes may be disposed at intermediate points of the network and they set up the layer 2 paths from the ingress to the egress of the network following the specified routes and a third node is disposed at the egress of the network.

Abstract: Coding a data stream is provided, wherein the data stream comprises at least one packet having a given packet length and respective partitions of the at least one packet are coded with different error protection rates, the respective lengths of the respective partitions being determined by respective predetermined percentages of the packet length or a fraction of the packet length.

Abstract: A digital data system comprises a plurality of links for passing messages between nodes, which may be end points such as memory or processing units, or intermediate or branch points such as routers or other devices in the system. A link level flow control is implemented by control symbols passed between adjacent nodes on a link to efficiently regulate message burden on the link. The control symbols may be embedded within in a message packet to quickly effect control on a link—such as reducing data flow, requesting retransmission of corrupted data, or other intervention—without disruption of the ongoing packet reception. A control symbol may be recognized within the packet by a flag bit, a marker such as a transition in a signal, or a combination of characteristics. The control symbol may be a short word, having a control action identifier code at defined bit positions to indicate the desired link-level control function.

Abstract: A transmission system is a data delivery system which includes a server for transmitting ES data and a receiving terminal for receiving the transmitted data. The server includes a conversion controller for determining elementary streams (ES's) and a scene description to be transmitted based on transmission priority levels and display priority levels, in accordance with the state of a transmission path and/or a request from the receiving terminal. The server also includes an ES processor and a scene description processor.

Abstract: A method of communicating digital information of different data formats via a plurality of communication channels shared between several communication means includes a reception operation, a reformat operation, and a transmission operation. In the reception operation, digital information having a first format and transmitted via a first communication channel from communication means that uses the first format is received. In the reformat operation, the received digital information having the first format is reformatted to digital information having a second format different from the first format, if resources to use a second channel for transmission of digital information having the second format are available. In the transmission operation, the digital information having the second format is transmitted via the second channel and is received by communication means that uses the second format.

Abstract: A network switch includes a data port for communicating with a data network, and a statistics counter coupled to the data port for monitoring operational parameters associated with the data port. The statistics counter includes statistics registers therein. A statistics gathering circuit is connected to the statistics counter for reading the statistics registers, and for transmitting the data from the statistics registers to a remote system memory. A method of monitoring port activity in the network switch includes storing port activity data in a statistics register on a network switch, then reading the port activity data with the statistics gathering circuit. The port activity data is transmitted directly to the remote system memory, thereby reconstructing the statistics register in the remote system memory. The remote system memory can then be accessed via a remote CPU to read the reconstructed statistics register.

Abstract: An approach for processing packets for transmission over a satellite communications network is disclosed. A communication system includes a satellite terminal that provides connectivity for a host. The satellite terminal includes a user interface that receives a packet associated with an application from the host, and classification logic that classifies the packet into one of a plurality of transport services based upon the corresponding application. The satellite terminal also includes a mapping logic that maps the one transport service to one of a plurality of packet delivery services, wherein the one packet delivery service provides transmission of the packet to the satellite. The system also includes a hub that is configured to communicate with the satellite terminal over the satellite to provide the plurality of packet delivery services.