Abstract: A data transfer flow control system includes a plurality of nodes or switches in a network, which are interconnected by transmission links. Resource management cells are transmitted along with data cells in information transfer sessions. As the amount of session traffic at any node increases, the level of occupancy of the buffers for that node correspondingly increases to temporarily store overflow data. At every network node, a “fair share” cell rate is determined for each output transmission link. Whenever the current cell rate (CCR) of any session exceeds the fair share cell rate for the output link at a node, the buffer occupancy threshold values for setting congestion indication fields in the resource management cells are adjusted downwardly such that a lower threshold buffer occupancy will effect a traffic congestion setting for that session.

Abstract: Flow control is implemented at a given node in a network of LAN switches by having the node monitor the occupancy levels of buffers or queues. When a buffer is found to be occupied or filled beyond a predetermined threshold level, a pause command is generated for the source currently supplying traffic to the buffer. A pause time PT is calculated using an equation which takes into account: the transmission rate of the identified source, the transmission rate of the output link servicing the congested buffer and queue length that can be occupied without a congestion condition being declared. To reduce the chance that queue lengths will “oscillate” about their threshold point due to multiple sources resuming transmission at the same time, each calculated pause time is adjusted to a randomly selected value PT(ran) falling within a range of PT±kPT where k may be on the order of fifty percent.

Abstract: The present invention relates to connectionless transmission in high speed packet switching networks, and in particular to a group addressing method and system for sending a datagram to one or a plurality of destination nodes and within these nodes for duplicating the datagram and to forward it to multiple end users. The claimed invention takes advantage of a specific data transfer mode called "Remote Access to Functional Addressing" allowing the sending of a datagram to a destination node and within said node, the duplication of said datagram for a transmission towards multiple destinations.

Abstract: A frame relay network relies on virtual connections to support the exchange of data through an intervening network from an originating end system to a remote destination end system. While permanent virtual connections or PVCs (connections which remain established even when data is not being sent) might be used to form the virtual connection, switched virtual connections (SVCs) are preferred within the network since such connections are cleared when not needed. Clearing a connection makes the resources previously allocated to the connection available for use by other end users. However, end user systems typically expect to see PVC service through the network, leading to difficulties in establishing SVCs end-to-end. To support continued use of PVC applications preserving availability of network resources, a Dynamic Permanent Virtual Connection or DPVC is defined. The DPVC provides an end user a capability to notify the frame relay network whether the resources of the SPVC may be released.

Abstract: A method and apparatus for flow control for sources in packet switched networks is implemented. A data rate for the source is determined based on a critically damped second-order system in response to a congestion signal sent by a destination node or other network device. The data rate is damped toward a share value that is also based on a critically damped second-order system. The resulting flow control reduces packet loss and improves network utilization.

Abstract: A magnetoresistive spin valve sensor is described. Such a sensor is also known as a GMR sensor or giant magnetoresistive sensor. The layers (24, 26, 28) of the sensor are mounted on a substrate (20) having steps or terraces on one of its face. The steps or terraces on the substrate's surface cooperate with one or more of the ferromagnetic layers (24, 28) of the sensor to determine the layers' magnetic properties. Specifically, the thickness of one or more of the sensor's layers can be set above or below a critical thickness which determines whether the easy direction of uniaxial magnetization of a layer of that particular material is fixed or "pinned". If pinned, the layer has a high coercive field. Thus, the new device avoids a biasing layer to pin any of the magnetic layers. Preferably the easy axes of the first two ferromagnetic layers (24, 28) are set at 90.degree. to one another in the zero applied field condition by appropriate choice of layer thickness.

Abstract: A protocol adapter for an Asynchronous Transfer Mode (ATM) cell switching system has a receive part and a transmit part, the receive part being arranged to convert an incoming ATM cell into a cell structured with a payload and a header including an output index (OI). The transmit part is arranged to convert the structured cell after it is routed through the switching system into an ATM cell, and to output the ATM cell on the ATM communication lines. The transmit part has cell processing logic for adding a bit (mother-bit) in the header of each incoming structured The output index of a mother cell is used to access a location in a look-up table which contains for each output index, a multicast bit for indicating whether the cell is to be multicasted or not, a queue index for indicating a location where to enqueue the cell before it is outputted from the transmit part, a new VP/VC/Li value for constructing a new header, and a next-output index.

Abstract: A method and an apparatus for searching a bit field whose significant bits comprise two contiguous bit fields such as the VPI/VCI bit fields of an ATM cell header. The invention uses a hash key based on CRC-n calculated on the bit field to be searched. One m bit field part of the significant bits of the bit field to be searched can be concatenated with the CRC-n to form a double hash key. It appears that, L being the total of the two contiguous bit field lengths, if L=m=n+p, p being greater or equal to 4, the scattering of data to be searched is perfect. The method comprised a first step of pointing to a first address with the hash (or double hash) key and reading a maximum of 2.sup.p addresses before reaching the addresses containing the bit field to be searched.

Abstract: Computer network management for electronic commerce requires technical implementations of business processes. The process addressed here is a technical method for a communication in which two or more parties legitimately want to communicate anonymously, often before discussing a deal or closing a business, e.g. for anonymous bidding or auctioning in electronic commerce. Essentially, the invention is a method, described by a protocol, for safely exchanging data in a network that provides a public key infrastructure and an anonymous communication possibility between network users. It consists of a sequence of steps in which both sender (e.g. customer) and addressee (e.g. merchant) compose data sets (i.e., requests and replies) that are based on received data and/or prior knowledge. The data sets are enciphered to provide anonymity, and digitally signed to provide proof of the partner. The invention is also a system designed to implement the invented method.

Abstract: A switch for use in an ATM network is disclosed. The switch is designed to perform a function beyond that normally achievable with a virtual path switch functioning in accordance with the ATM standard. The switch according to the invention has data stored in a look-up table (431-433) which allows it to identify communication cells of particular individual virtual channels, indicated by the virtual path identifier (VCI), although these cells cannot be distinguished on the basis of their virtual path indicators (VPIs). This identification is attempted before the usual step of forwarding an incoming communication cell based solely on its virtual path indicator. A priority circuitry (44) ensures that entries associated with the combined VPI/VCI is given a priority over those associated only with the VPI. The switch can extract cells of individual virtual channels passing through it. It can also insert virtual channels into the ATM network.

Abstract: A method and apparatus creates a set of routes for use in assigning the optimum route for a communication in an ATM digital broadband communication network consists of one or more links, each link connecting one node in the network to one other node. Assignment of a route is made from a set of. Each optimum route in the set is that route offering the best possible value of an additive attribute of the network, such as signal delay, number of nodes or route cost, for a particular minimum acceptable value of a restrictive attribute of the network, such as bandwidth of the route. The calculation of the optimum route involves finding the best route with respect to the value of the additive attribute for a model or representation of the network containing only those links in the network having at least a particular value of the restrictive attribute.

Abstract: Method and system for controlling the state of a system bus during live insertion and removal of a pluggable feature card (FC) by driving control signals, which are transferred over the system bus, to an active signal level, or by driving down level active control signals to a low signal level near ground level. By this mechanism, the system bus becomes immune to signal disturbances and thereby allows pluggable units to be live inserted and removed without causing adverse effects to the system such as a system reset or compromise of data integrity. During live insertion or removal, a Live Insertion Bus Controller (LIBC) acquires access to the system bus through its interface with a System Bus Controller (SBC), after it has been signalled by a live insertion mechanism associated with the FC that the FC is in the process of being live inserted or removed.

Abstract: A bin packing algorithm is employed to schedule computer network activities, such as pause times required for operation of an Ethernet network which implements existing IEEE 802.3x standards. In such a network, any node in the network can control the flow of traffic from upstream stations in order to avoid congestion at the flow-controlling node. Upon sensing congestion, the flow-controlling node determines how long each upstream node contributing to the congestion should pause transmission over the next control interval. In accordance with the invention, the pause times are scheduled or staggered by using the bin packing algorithm to sort the sources into one or more bins. One required bin property is that there is no overlap in pause times for the sources within a particular bin. Another required bin property is that the sum of the pause times within a bin can be no greater than the length of the control interval.

Abstract: This invention defines a routing method which allows a determination of best paths from link weights in situations where these weights are not additive, but the characteristic of a concatenated path is determined mainly by single "bottleneck" links. To be compatible, the metric must be chosen from a specific set of metrics, called bottleneck metrics in this description. The new widest-path method has some characteristics in common with the known Dijkstra method for additive weights. Implementations in communication networks are disclosed which lead to new nodes, new networks and new network protocols.

Abstract: A process and an apparatus to calculate the FCS (Frame Check Sequence) error checking code of packets payload sent over a fixed size packet networks in a network equipment sending said packets and to check said FCS in the network equipment receiving said packet; this invention applies to calculations of FCS based on CRC (Cyclic Redundancy Checking) codes generated by the polynomial generator of degree 10, G(X)=X.sup.10 +X.sup.9 +X.sup.5 +X.sup.4 +X+1. Particularly, this invention is for use in the ATM layer of ATM nodes processing OA&M and AAL3/4 ATM cells. The solution consists in using the calculation of the FCS based on the CRC code generated by the polynomial generator of degree 9, X.sup.9 +X.sup.4 +1 and simple operations. The calculation and the checking of the FCS is simple and thus the performance are improved authorizing the support of higher speed network lines.

Abstract: A system adapts access to a packet switching network. A dynamic bandwidth adaptation continuously monitors the mean bit rate of a signal source and the loss probability of a connection in the network. A filtering means removes noise from the mean bit rate and loss probabilty. A test means determine whether the values fall within a pre-defined acceptable adaptation region in a mean bit rate, loss probability plane. Triggering means initiate bandwidth adaptation procedures when the values fall outside of the region which in turn, initiate means for acquiring a new connection bandwidth, and determining new parameters for the adaptation mechanism.

Abstract: Provided is a method and system for displaying a list of items in point of sale transactions on a touch screen user interface by virtually adjusting the display area of a touch screen user interface. The method and system achieve the forgoing by the following steps. Detecting a selection and manipulation of the icon utilized as a virtual handle for expanding and contracting the window for displaying said list of items in point of sale transactions. Determining whether the window for displaying said list of items in point of sale transactions is in either an expanded or contracted state. If it is determined that said window for displaying said list of items in point of sale transactions is in a contracted state, enlarging the window for displaying the list of items in point of sale transactions in response to the detected manipulation of the icon utilized as a virtual handle.

Abstract: The invention relates to asynchronous transfer mode (ATM) connections that are segmented into separate feedback control loops. A virtual destination (VD) of a given segment provides feedback to the virtual source (VS) of the same segment. The feedback is based on flow control information provided by the VS of the adjacent downstream segment. Information is transferred across segment boundaries by using a data table shared by the VS of one segment and the VD of the adjacent upstream segment. The actual Allowable Cell Rate for a segment is written into the table, from which it can be extracted by the VD of the next upstream segment. VS/VD switches are implemented in either a centralized or a distributed configuration.

Abstract: For storing and retrieving data, the present invention enhances performance by allocating a single oversized contiguous storage area and by allowing data wrapping. Reliability is insured by verifying the coherence of stored variable length records at each READ operation. The coherence verification is optimized because the information required for verification, comprising a set of key values, is stored in the records themselves.

Abstract: A method and apparatus for discriminating between voice and voiceband data (fax/modem data) in an input signal from a voiceband channel, which is available by blocks (packets) of samples. Said discrimination is based upon the computation of two characteristics of the input signal: an autocorrelation function and a power variation function, the combination of which provides a discrimination factor which is highly accurate while requiring a low computing power.