Abstract: Redundancy, expanded switching capacity and fault isolation arrangements for use with an expandable telecommunications system. An inter-nodal network connects a plurality of programmable switching nodes or other nodes. One or more additional inter-nodal networks may be provided across some or all of the ones. The bandwidth provided by the additional network(s) may be used to provide redundancy against failure of the primary network or the nodes, increased switching capacity or a combination of both. In addition, faults which occur either within a particular node or within an inter-nodal network may be effectively isolated and prevented from degrading system performance.

Abstract: A method and apparatus for providing hardware-assisted CPU access to a forwarding database is described. According to one aspect of the present invention, a switch fabric provides access to a forwarding database on behalf of a processor. The switch fabric includes a memory access interface configured to arbitrate access to a forwarding database memory. The switch fabric also includes a search engine coupled to the memory access interface and to multiple input ports. The search engine is configured to schedule and perform accesses to the forwarding database memory and to transfer forwarding decisions retrieved therefrom to the input ports. The switch fabric further includes command execution logic that is configured to interface with the processor for performing forwarding database accesses requested by the processor.

Abstract: A connection switching circuit is disposed in each node of a ring system in which a first ring and a second ring are provided with two communication lines which allow data to flow in a different direction respectively and is connected with a currently used passage and preliminary passage. The connection switching circuit comprises an alarm correction reading part for generating a control signal, an alarm monitor part for outputting respective alarm detection signals, a currently used/and preliminary alarm recognition part, and a switching control signal generation part for generating a control signal for selecting a passage, wherein either the currently used passage or the preliminary passage is selected by monitoring the alarm of the data which flows on the currently used passage or the preliminary passage to connect the first ring and the second ring with each other.

Abstract: A redundancy switch (44) provides interfacing of network signals to spare network processors (46) in the event of a failure of a main network processor (42). A redundancy switch (44) allows for monitoring and diagnostic operations to be performed on network electrical signals without interrupting traffic flow on inbound and outbound paths. A redundancy switch (44) performs a loopback diagnostic by routing signals from transmitter portions of the spare network processors (46) to selected receiver portions. The redundancy switch (44) includes a receiver interface unit (90) and a transmitter interface unit (92) capable of routing inbound and outbound customer signals to and from the spare processors (46) for monitoring, diagnostic, and sparing purposes.

Abstract: A system of elementary processors in array form organized in accordance with a plurality of nodes with SIMD operation, each having a plurality of elementary processors connected to one another so as to form a ring of elementary processors, each elementary processor being associated with a connection cell connected to the cells of neighbouring elementary processors in order to form a ring network. Each SIMD node is provided with a memory and addressing module ensuring an addressing independence of the node, as well as a control unit connected to the control units of neighbouring nodes in order to form an internode control network in which priority tokens circulate, each memory and addressing module of a node being connected to the memory and addressing module of neighbouring nodes so as to form an internode data network. The system may find one application in the simulation of fluid flows.

Abstract: Protection Bundles (PB) facilitate efficient protection switching in a network and can be applied at any network layer. A PB is preferably assigned to all working signals sharing the exact same protection facilities. The working facilities that a PB traverses define a Bundled Protection Fragment (BPF)(560, 564, 568). The end-points of the BPF exchange coordination protocol messages along the protection facilities when necessary. The protection facilities between the end-points of a BPF define each BPFs Common Protection Route (CPR)(562, 566, 570).

Abstract: A failure detector, connected to receive a signal from an interface at a lower level than the SONET level, detects a failure in that interface, such as a fiber cut or the loss of signals. An AIS generator is responsive to the detection of a failure by the failure detector to generate an AIS at the SONET level (STS and VT levels). A signal processing circuit converts a low-level signal from the interface to an SONET-level signal. When receiving the SONET-level AIS from the AIS generator, the signal processing circuit inserts it onto the SONET-level signal for application to SONET ADMs.

Abstract: A dual-ring, multiplexed-communications network to deliver protected service to nodes where protection is required, while simultaneously other nodes of the same network, where only unprotected commodity service is needed, are not burdened with the cost of duplicated optical and electronic equipment.

Abstract: A system and method for restoration of a disrupted telecommunications path between a source node and a destination node via at least one tandem node. The operation of the present invention proceeds in five phases: notification, broadcast, path trace-out, confirmation and cleanup. In the notification phase, the path's source and destination nodes are notified of the disruption. In the broadcast phase, the network is flooded with PACK messages to locate restoration paths; selective rebroadcasting of the PACK messages limits the volume of restoration message traffic. In the path trace-out phase, bandwidth is conservatively reserved along the restoration paths indicated by the PACK messages. In the confirmation phase, restoration paths are built up step-wise along the traced-out paths, thereby restoring the disrupted path between the source and destination nodes.

Abstract: An ATM communication system including a plurality of communication nodes connected in a loop form by buses, buffers disposed in each communication node, a synchronizing pulse generation circuit for conducting cell demultiplexing of all communication nodes at the same timing, storage devices disposed in each communication node to store mounting position information of the communication node and slot generator position information, and a circuit used by each communication node to automatically transmit and receive cells on the basis of position information described above.

Abstract: Protection is provided by switching an optical transmission signal. An optical transmission system operating in a ring configuration, comprises optical transmitters and optical receivers connected in such a way as to provide working and protection on paths. When a failure occurs that disrupts the signal between two telecommunication nodal sites, optical switches are used to switch the signals from a working path to a protection path away from the disruption.

Abstract: An apparatus and method for fault isolation and bypass in a dual ring communication system provides a reconfiguration unit capable of attachment to a dual ring communication system having a plurality of reconfiguration units. The disclosed reconfiguration unit has a single adapter to the dual ring communication system and includes isolation and wrap switches capable of isolation and bypass of faults. A reconfiguration unit having a single adapter to the dual ring communication system detects failures on the ring and generates a failure frame which if not received from the ring causes the reconfiguration unit to enter a downstream wrap state. The reconfiguration unit enters an upstream wrap state if a failure frame is received from the nearest downstream reconfiguration unit.

Abstract: A bidirectional line switched ring BLSR network connects a plurality of nodes in a ring formed by transmission lines. In the network, in normal operation each node sends a subsequent node address contained in an APS byte of the K1 and K2 bytes in a multiplexed signal overhead to the subsequent node. When detecting a trouble of a transmission line, each node adjacent the trouble sends the address of a node normally connected thereto via the troubled line. The bidirectional line switched ring network control system provides each node with a bypass circuit for the APS byte and an address comparison circuit for comparing the address in the APS byte with a current node address. Each node closes the bypass circuit and receives the APS byte when the result of comparison proves coincident, and opens the bypass circuit and allows the passage of the APS byte when the result proves non-coincident.

Abstract: An interlocking apparatus capable of expanding a network while effectively using survivability of a self-healing ring, including a ring network connecting a plurality of nodes having a loop back function and a supplementary node connected to the first and second nodes of the ring netwrok. In the first node, a service selector selects a normal signal from the two signals sent from the second node and the supplementary node to output the selected signal to a next stage node. In the supplementary node, a path selector selects a normal signal from the two signals sent from the first and second nodes to output the selected signal outside the ring network. The service selector and the path selector include a monitor controller for always selecting the normal signal from the two input signals and further judge and determine a trigger for executing a switching or a switching direction in an autonomous distributed manner.

Abstract: An ATM communication system including a plurality of communication nodes connected in a loop form by buses, buffers disposed in each communication node, a synchronizing pulse generation circuit for conducting cell demultiplexing of all communication nodes at the same timing, storage devices disposed in each communication node to store mounting position information of the communication node and slot generator position information, and a circuit used by each communication node to automatically transmit and receive cells on the basis of position information described above.

Abstract: An ATM communication system (ATMK) has communication equipment (K1, K2, K3) that are arranged in a ring circuit system (RS) formed of two ring circuits (RING0, RING1) operated in opposite directions. Ring loops can thereby be established via the communication equipment in order to be able to switch from an active path to an alternate path as needed in the transmission of message cells. In the respective communication equipment, the message cells are respectively preceded by an internal cell header wherein, among other things, a path-associated sequence number is contained. Over and above this, the sequence number anticipated next or, respectively, the sequence number that most recently appeared is retained and path-associated in the respective communication equipment.