Abstract: A master node transmits a probe packet for checking a condition of a network in a ring in both directions thereof to detect the occurrence of a fault on the ring. A slave node increments a hop count included in the received probe packet, transmits it to an adjacent node configuring the ring, and transmits a hop count report packet to the master node. The master node detects a fault on the ring based upon a fact that the master node does not receive the probe packet transmitted by itself. Further, the master node detects the occurrence of multiple faults and the recovery of at least one of the multiple faults based upon the sum of maximum values of hop counts in the hop count report packets received from both directions of the ring and transmits a packet for prompting the update of the database for packet transfer.

Abstract: According to the invention, techniques for detecting and recovering from errors occurring in disk drive subsystems having a controller and drive units connected by a fibre channel loop. Specific embodiments can provide storage subsystems, methods and apparatus for use in information processing environments, for example. Embodiments can determine when each drive is disconnected from the loop in the external storage subsystem structured by using the FC Loop, and thereupon, the FC Loop can be controlled by bridging the communication path using the PBC so that the loop is not broken.

Abstract: In one embodiment of the invention, a Peer-to-Peer (P2P) subsystem includes a cache of a current peer and a peer locator. The current peer is in a current ring at a current level. The cache stores information of ring peers within the current ring. The current ring is part of a hierarchical ring structure of P2P nodes. The hierarchical ring structure has at least one of a lower level and a upper level. The peer locator locates a target peer in the cache in response to a request.

Abstract: In distributed multinode data processing systems, mechanisms are employed to insure that the nodes are properly informed about the liveness of the other nodes in node groups in the network. In particular, the present invention employs group membership indicia as part of a mechanism for detecting that a node and/or its adapter have failed and have been recently restarted. Having detected this situation, group membership inconsistencies which it can engender are avoided.

Abstract: A circuit arrangement, node, clustered computer system, and method incorporate a primitive communication mechanism for use in exchanging data between adjacent nodes coupled via a point-to-point network. A plurality of network ports are used to couple a node to other nodes in the clustered computer system over point-to-point network interconnects, and a plurality of communication registers are associated with each of the network ports for the purpose of storing data received through their associated network ports. A node desiring to communicate information to another node receives a port identifier from the other node that identifies the network port on the other node through which the pair of nodes are coupled. The port identifier is then used by the node to communicate data to the other node through the use of one or more write operations directed to the communication register on the other node that is associated with the network port identified by the port identifier.

Abstract: A master node in a packet ring network periodically sends a packet containing a discovery marker into the packet ring network. As each node in turn receives the packet, each adds its own discovery marker, which contains its topology information, to the packet, saves the topology information of others, and resends the packet to the next node in the ring. Eventually, the master node receives the packet containing a chain of discovery markers for all active nodes terminated by the master's own discovery marker, so the master node then removes its own discovery marker and resends the packet in to the ring network. Each node in turn then removes its own discovery marker. In this way, all nodes in the ring see topology information for every other active node.

Abstract: A distributed multi-axis motion control system comprises a multicast communications network having several node components. Each of the node components includes a clock and an actuator. The actuators are part of a motor system and a pattern profile table of the motor system is generated. The pattern profile table is translated into a separate single-direction-of-motion pattern table to separately direct the motion of each of the actuators of the node components. A grandmaster clock generates synchronization signals which are transmitted through the network at a sync interval and which synchronize the clocks. Time-bombs are generated at an interval which is a whole number multiple of the sync interval. The time-bombs cause concurrent execution of the first and subsequent steps from the single-direction-of-motion pattern tables to produce synchronized multi-axis motion of the motor system.

Abstract: Cascade control logic for use in a switch or other network unit that can be used in a cascaded stack can maintain normally a point-to-point half-duplex connection for control data with each of the next preceding and next succeeding units in the cascade. Each cascade logic device is organised so that for one direction, conveniently called the up direction, a device is a master and in the other direction the device is a slave in respect of the control path. A control device will generate master control frames in the up direction and deliver slave control frames in the down direction. The control device is organised so that in the absence of reception of valid control frames on a control link control data which would otherwise be sent out on that link is looped back within the control device. In this manner the control device can maintain under normal circumstances two virtual control channels which can ‘self-heal’ notwithstanding the failure or powering-down of a unit in the cascade.

Abstract: The number of nodes that can be identified is increased without redefining switching request and switching status fields in existing K1/K2 bytes. Eight bits are assigned to a node ID field, and source node ID is stored in the node ID field when transmitting over a short path, while a destination node ID is stored in the node ID field when it transmitting over a long path.

Abstract: The invention provides a method of managing a network in which the configuration of communication devices can be freely modified and each terminal can operate as a hub terminal for controlling the network, and a communication device. Following network management information transmitted by the hub terminal periodically, each leaf terminal transmits terminal synchronization information and then transmits data. The network management information includes network ID retained by the hub terminal, station ID information in the form of information indicating the use/non-use of station ID in the network, and a terminal synchronization information transmission request which designates the leaf terminal which should transmit a terminal synchronizing signal. The leaf terminals designated by the terminal synchronization information transmission request transmit the individual terminal synchronization information sequentially following the network management information.

Abstract: N shared data registers are provided for N+1 processors, respectively. For allowing all the processors to read the same data from the shared data registers, the processors are connected by interprocessor communication channels. The processors are classified into a master processor and subordinate processors. All data writing into the shared data registers are executed from the master processor. Further, data writing into the shared data registers from the subordinate processor is executed from the master processor after a write request is sent to the master processor.

Abstract: This invention relates to apparatus and associated methods for providing access to and switching of information in a packet data network. More particularly, the invention is directed to a platform facilitating both packet switching capabilities and associated access interface functions in a single system.

Abstract: One aspect of the present invention relates to an information appliance for handling streaming information for storage in a circular buffer having a plurality of partitions defined by boundaries. The information appliance includes receiving streaming information from a source of streaming information and forming data blocks wherein each data block includes a payload field capable of holding a portion of the streaming information and an identification field indicative of the source of the streaming information. At least one data block is written to the circular buffer to partially fill a partition and at least one padding block is generated having a field indicative of non-streaming information and having a size being a function of remaining space in the partition. The padding block is written to the circular buffer adjacent a boundary of the partition.

Abstract: In a synchronous hierarchic network having multi-level tandem connection monitoring, all of the fields containing tandem connection monitoring information associated with trail terminations at a subject network element are processed in parallel at the subject network element. The network element extracts the tandem connection monitoring information from received signals independently for each of the tandem connection monitoring terminations occurring at the network element.

Abstract: A motion control system and method that includes a central controller configured to generate first and second demand control signals to be used to define actuation motion of respective first and second actuators. The central controller is in communication with first and second nodes by way of a data network, each node including at least a respective actuator configured to implement at an actuator time a motion or force-related effort based upon the respective demand control signal. Each node also includes a memory configured to store at least one respective propagation delay parameter related to a signal propagation delay between the central controller and the node. A timing mechanism establishes timing at each node based on the respective propagation delay parameter so that the actuator time at the nodes occurs simultaneously. Strictly cyclic and/or full-duplex high-speed communication can be supported. The network can be wired in a ring or as a tree and with twisted pair cabling or fiber.

Abstract: A ring-shaped network quickly performs initialization even when a plurality of data transmission apparatuses are connected thereto. Each data transmission apparatus outputs received data to a device connected thereto while performing establishment of clock synchronization based on the received data, and when synchronization is established, it resends the received data. Further, when synchronization of the connected device is established, it sends data supplied from the connected device. Further, a master data transmission apparatus outputs data at turn-on of power or immediately after reset, and a next-stage slave data transmission apparatus receives the data to establish synchronization, and resends the received data when synchronization is established. Thus, synchronization of all the data transmission apparatuses is established while making a round of this data, and then synchronization of devices connected to the respective data transmission apparatuses is established.

Abstract: A communications interface system and method for a plasma generator is provided. The communications interface system includes a power delivery system component that has a standard POD interface for communicating information that complies with a first protocol. A portable device is coupled between the standard POD interface and a second communication interface for communicating information therebetween. The second communication interface communicates information in a format that complies with a second protocol. The portable device is detachable from the standard POD interface and the second communication interface. A first communication link couples the standard POD interface to the portable device. A second communication link couples the portable device to the second communication interface.

Abstract: A method of bandwidth management for ensuring a guaranteed bandwidth to each station of a transmission network (18) comprising a plurality of stations (10, 12, 14, 16), forming a logical ring wherein one of the stations is the ring manager and wherein a token frame is circulating along the logical ring from station to station, each station being allowed to transmit data to other stations over the transmission network when it receives the token frame while holding the token during the time the station is transmitting data. A credit of data bytes allowed to be transmitted is allocated to each station upon reception of the token frame when an Utilization Rate based upon the number of data bytes sent by all stations since the preceding reception of the token frame is greater than a predetermined threshold.

Abstract: A method of bandwidth management over a transmission network comprising a plurality of stations forming a logical ring that circulates a token from station to station. Each station is allowed to transmit data to other stations over the transmission network when it receives the token. The station is allowed to transmit C bytes, where C is a credit. The credit increases in proportion to the time spent since the preceding reception of the token by the station.

Abstract: Units of traffic are routed between nodes in a network on corresponding sets of trunks, such that the traffic is balanced between disjoint paths. A restoration process for the traffic is implemented using service layer or transport layer switching. In a first embodiment, first and second nodes are connected by first and second sets of trunks, with each of the trunks in a given set of trunks supporting a designated portion of a given one of the units of traffic. The units of traffic are then routed such that a first half of a given one of the units of traffic is routed on a first one of the trunks in a given one of the sets of trunks, and a second half of the given unit is routed on a second one of the trunks in the given set of trunks. In other embodiments, the first and second nodes are connected by first and second sets of trunks so as to form a four-trunk ring, with each of the first and second sets of trunks including a primary trunk and a backup trunk.

Abstract: An apparatus for scheduling transmission of a plurality of frames in a network having a plurality of nodes, each frame identified by a type designation, includes a schedule memory and a sequencer. The schedule memory stores a transmission time for each frame type and a list of frames to be transmitted. The sequencer is operable to access the schedule memory and initiate transmission of the frames in the list.

Abstract: A fault-testing node for a connectionless data link has at least two opposing communication ports; a soft switch for controlling port-to-port data flow through the device; and an instance of software for modifying packet header information. The node enables loop-back testing by one or more port-to-port data flow paths being switched through activation of the soft switch to loop incoming packets back to the sender of the packets through the device and wherein the instance of software reverses the order of source and destination addresses of data units to insure acceptance of looped data units at the sender station.

Abstract: A method for configuring a computer network that includes a full duplex bi-directional first port and an initiator that can issue a request for the first port to assume a state. The first port, when in a first state, is able to bi-directionally communicate with a full duplex bi-directional second port, and when in a second state, is coupled to itself by having an output thereof coupled to an input thereof. The method comprises inhibiting the initiator from issuing the request, sending data to the initiator describing a desired state of the first port, and enabling the initiator to issue the request for the first port to assume the desired state.

Abstract: A method and system for routing an externally generated message in a network includes receiving at an ingress port of a network a message from an external network. The message includes Internet protocol (IP) source and destination addresses and message data. The IP source and destination addresses are translated to internal addresses that are non-forwardable in the external network. The message data is routed in the network based on the internal addresses.

Abstract: An auto-negotiation (AN) method for establishing a high speed link between first and second transmitting devices in a gigabit Ethernet using the 1000 Base-t standard includes transmitting and receiving a base page indicating a transmission capability between the first and second transmitting devices. A message page is transmitted and received that indicates a 1000 Mbps transmission capability between the first and second transmitting devices and a specific state. A first unformatted page is transmitted and received that indicates transmitting speeds and modes, and port types of the first and second transmitting devices. A null page is transmitted and received after the first unformatted page, upon determining a master and slave from among the first and second transmitting devices based upon the first unformatted page. A high speed link is established between the first and second transmitting devices and the AN method is terminated.

Abstract: A method and apparatus for adding a node to a network where the network includes a plurality of nodes connected by first and second rings formed by two or more transmission media. The method includes connecting the node to each of the first and second rings, determining a ring identifier for each of the first and second rings coupled to the node after connection, discovering topology information for the network including the identity of each node coupled to each ring, storing the topology information and determining routing decisions for one or more packets received at the node along each of the first and second rings using the ring identifier information.

Abstract: A collision-free protocol for transmitting frames between stations connected over a shared transmission medium such as an IEEE 802.3 Ethernet LAN. A logical ring is formed and a token is circulated among the connected stations part of the logical ring (not all connected stations are required to be part of the logical ring). Transmitting from any one station, part of the logical ring, is permitted only while holding the token, therefore preventing collisions. A collision-free protocol, over a standard Ethernet infrastructure, becomes feasible, yet remains compatible with the standard collision protocol, thus improving performances.

Abstract: A collection/distribution server divides processing task accepted from a customer terminal into a plurality of processing units, and transmits the units to at least one or more user terminals. The collection/distribution server receives processing results of execution on the user terminals, and integrates the processing results to send back to the customer terminal. The user terminal registers with an application server in advance for receiving a task commission from the collection/distribution server, and receives a license application from the application server. When the license application receives a processing unit from the collection/distribution server, the license application executes the processing on the user terminal. The license application sends back a result of the processing to the collection/distribution server via a network. The user terminal receives a specified service as good value for executing the processing task substituting for a contractor.

Abstract: A motion control system and method that includes a central controller configured to generate first and second demand control signals to be used to define actuation motion of respective first and second actuators. The central controller is in communication with first and second nodes by way of a data network, each node including at least a respective actuator configured to implement at an actuator time a motion or force-related effort based upon the respective demand control signal. Each node also includes a memory configured to store at least one respective propagation delay parameter related to a signal propagation delay between the central controller and the node. A timing mechanism establishes timing at each node based on the respective propagation delay parameter so that the actuator time at the nodes occurs simultaneously. Strictly cyclic and/or full-duplex high-speed communication can be supported. The network can be wired in a ring or as a tree and with twisted pair cabling or fiber.

Abstract: Methods and apparatus for Fibre Channel interconnection is provided between a plurality of private loop devices through a Fibre Channel private loop device interconnect system. In the preferred embodiments, the Fibre Channel private loop device interconnect system is a fabric or an intelligent bridging hub. In one aspect of this invention, a Fibre Channel private loop device is connected to two or more Arbitrated Loops containing, or adapted to contain, one or more private loop devices. Preferably, the interconnect system includes a routing filter to filter incoming Arbitrated Loop physical addresses (ALPAs) to determine which Fibre Channel frames must attempt to be routed through the fabric. Numerous topologies of interconnect systems may be achieved.

Abstract: The present invention relates to a ring system, in particular to a ring control node which increases the upper limit of the number of nodes that can be arranged on one ring by a BLSR control and conforms to an increase in line capacity and the scale of a system. The ring control node made of a plurality of nodes for performing ring control, and spans for connecting the plurality of nodes in a ring shape, and each of the nodes detects a fault occurring in a span between itself and another node adjacent thereto, and transmits the fault information to the other node using, as a destination, a span ID assigned to the span.

Abstract: A method and apparatus for switching data of different protocols through a network are described. In one embodiment, a method includes receiving data from a number of interfaces. Additionally, the method includes switching the data through a first switch fabric upon determining that the data is being processed as packet data. The switching of the data through the first switch fabric includes de-encapsulating a first number of protocol headers from the packet data. The switching of the data through the first switch fabric also includes encapsulating a second number of protocol headers from the packet data. Moreover, the method includes switching the data through a second switch fabric upon determining that the data is being processed as Time Division Multiplexing (TDM) traffic.

Abstract: A method of provisioning a connection across a SONET/SDU network formed from multiple sub-networks comprises: determining a model of the entire network, the model indicating the connections between all sub-networks, and representing each sub-network as a single unit; calculating a route between the sub-networks containing the first and second nodes using the model; passing the signals along the determined route, and determining the route between nodes within each sub-network locally within the respective sub-network. This method enables a simplified model of the network to be stored in each node of the network, so that a route calculation can take place at the sending node. The specific route through the network is determined as the signal passes through the network, as the specific path through individual sub-networks is determined locally.

Abstract: A point-to-multipoint communications network connecting multiple subscribers to a single communications line. A plurality of subscriber communications interfaces are connected in parallel to form a local group in which one communications interface serves as a master communications interface and the other communications interfaces serve as slaves. Each communications interface may be capable of serving as the master communications interface according to a demand division multiplexing technique, which assigns master status based on upstream data demands. As a communications interface is switched to master status, the communications interface previously holding master status is switched back to slave status. A plurality of communications interfaces can thus be connected to a single communications port without increasing the upstream transmission bandwidth requirements.

Abstract: In a chassis for holding drawers containing computer components or the like, accurate alignment of each drawer in its corresponding slot is provided by a plurality of alignment features along an edge of an opening for the drawer. Mating alignment features are provided in each drawer, that engage with the alignment features on the chassis to ensure alignment of the drawer in the chassis. Various different types of alignment features are provided. Mating alignment features may additionally be provided along an opposing edge of the chassis and drawers. After being aligned, the drawers may be fastened to the chassis in a conventional fashion.

Abstract: The invention provides methods and systems for provisioning fault-tolerant ring structures that do not necessarily involve fully provisioning all spans of a ring with service capacity. The system allows a plurality of nodes to be connected in a ring structure. The ring structure can allow a ring to be provisioned without a continuous loop of service capacity around all legs of the ring. This postpones or totally avoids the cost of service capacity until a demand requires it. Only protection capacity is required to close the loop, and the decision to add working capacity can be made as warranted. At the same time, this ring structure can retain its fault-tolerant nature and also provide acceptable performance.

Abstract: A WDM ring network and method for distributing within such ring network for feeding in data and for distributing both working signals and protection signals on different transmission paths and in oppositely directed transmission directions, and for forwarding data from subscribers and for distributing the working signals to the subscribers.

Abstract: The symmetric multiprocessor system includes multiple processing nodes, with multiple agents at each node, connected to each other via an interconnect. A request transaction is initiated by a master agent in a master node to all receiving nodes. A write counter number is generated for associating with the request transaction. The master agent then waits for a combined response from the receiving nodes. After the receipt of the combined response, a data packet is sent from the master agent to all intended one of the receiving nodes according to the combined response. After the data packet has been sent, the master agent in the master node is ready to send another request transaction along with a new write counter number, without the necessity of waiting for an acknowledgement from the receiving node.

Abstract: A computing component is provided for use in a client computer which has a client processor. The computing component includes a remote management processor that is operable to selectively control the client computer independently of the client's own processor or processors. The computing component also includes a network component that facilitates communication between the computing component and a remote management machine. A method of managing one or more clients in a computer system is also provided, where the clients have a client processor and a computing component installed on client. The computing component is independent of the client processor and is operable to selectively control the client. A network component is installed on the computing component. The method includes remotely controlling the client by communicating with the computing component through the network component utilizing a remote manager.

Abstract: A peer-to-peer protocol is based on the use of global timestamps and client priorities in serializing modifications to a shared workspace of real-time collaboration. The method caters to dynamic clients wherein a client can leave or join an ongoing collaboration session as long as there is always at least one client present/remaining in the collaboration session. The method can support multiple definitions of a modification, including partitioning-based definitions, wherein the method provides full support for locking of partitions, and a full treatment of inter-partition synchronization via a modification definition over multiple partitions. The method is capable of utilizing the many standard methods of creating a global, distributed, synchronized clock for the global timestamps utilized by it. The method is rollback-based for correcting tentative but incorrect serializations, and provides additional backup in terms of checkpoints for additional safety and for the support of lightweight, pervasive clients.

Abstract: A method for fault protection in a bidirectional ring network includes transmitting first and second flows of packets around the bidirectional ring network while defining the first flow as a wrapping flow and the second flow as a non-wrapping flow. Upon detection by a node in the network that a segment of the network proximal to the node has failed, the packets in the first flow are wrapped at the node between clockwise and counterclockwise directions on the network so as to avoid the failed segment, while the packets in the second flow are not wrapped.

Abstract: According to one embodiment, a system for controlling passing of a token among a plurality of clients that access a shared resource includes at least one controller. The at least one controller is configured to cause the token to be passed to each of the plurality of clients when the system is in a first state, and to cause the token to be passed to fewer than all of the plurality of clients when the system is in a second state. According to another embodiment, a token-ring system includes a shared resource, at least first and second clients that access the shared resource, and error detection logic. The first client includes a primary device and a secondary device which provides bootstrap information to the primary device. The error detection is configured to directly monitor the secondary device for an anomaly in the operation thereof. According to yet another embodiment, a method is disclosed for operating a multi-port memory including at least first and second memory ports that access a shared memory.

Abstract: A method for distributing sets of collision resolution parameters to be used for resolution of network access contention events among nodes of a non-centralized media access control shared medium network. A set of collision resolution parameters is provided which includes a sequence of fixed numbers for resolving a single network access contention event. A single collision signal slot master node is identified when one or more candidate collision signal slot master nodes exist. Collision signal slot request messages are sent from client nodes addressed to all network nodes. Collision signal slot assignment messages are sent from the master node to the client nodes. A collision resolution parameter set to be employed by that given client node is obtained at a given client node from within a received collision signal slot assignment message. Collision signal slot acknowledgment messages are sent from client nodes addressed to all network nodes.

Abstract: A communication system, network interface and communication port is provided that includes a media local bus. The local bus is connected between a controller and one or more multimedia devices located within a node of the communication system. The controller periodically broadcasts sync signals to the source device, or devices, to synchronize data transmission partitioned into time slots. Each time slot represents is dedicated to a particular data type. Thus, time slot 1 can accommodate packetized data, time slot 2 can accommodate synchronous data, time slot 3 can accommodate control data, and time slot 4 can accommodate isochronous data. Various combinations and variations of those time slots can occur where fewer than four data types can be present within a frame or all four data types can be present. The local bus includes a signal line and one or more data lines.

Abstract: A dual-axis RAID system includes a plurality of X-axis ordinal series of disks, configured to store parity data and a tape drive, and a Y-axis ordinal series of parity disks. The Y-axis series is smaller than the X-axis series, because the X-axis series contains an extra disk configured as a segment journal disk. The RAID system communicates with clients on a network a network via an SCI network interface.

Abstract: A computer system comprises a plurality of modules and a shift register having a plurality of slots connected in series, wherein each of the plurality of slots is coupled to one of the plurality of modules. In one embodiment, an output of a last slot of the plurality of slots is coupled to an input of an initial slot of the plurality of slots to form a ring. Each slot of the shift register corresponds to a time slot on the ring, and each of the time slots is assigned to one of the modules. At least two of the modules are configured to independently generate frames for transmission on the ring. In another embodiment, at least one of the modules comprises a bridge module coupled to communicate with other bridge modules separate from the plurality of modules.

Abstract: A ring-mesh network architecture is provided for increasing the working/protection bandwidth ratio (W/PBR) of transport networks. The ring-mesh network has mesh connections between some nodes, the traffic on the mesh connections being unprotected. This increases the W/PBR from the current 1:2 value to (n?2)/(n?1), where n is the number of nodes, (n?1) is the number of connections on each node and (n?2) is the number of working connections on each node for one direction of traffic. Ring-mesh networks with add/drop multiplexers in the mesh connection are also provided.

Abstract: A distribution of location information in IP networks by intelligent endpoints is presented. The network comprises an intelligent endpoint operably coupled to a plurality of clients. A first one of the clients registers with the intelligent endpoint that stores location information of the first client. A second one of the clients may also register with the intelligent endpoint that stores the location information of the second client. The intelligent endpoint automatically presents the location information of the first client to the second client and of the second client to the first client. The first client can then directly communicate with the second client. Either client can also be an intelligent endpoint.

Abstract: A method and apparatus for a configuration ring is described. The method and apparatus include a configuration ring including a master, a first target, and a second target, the master coupled to the first target through a ring, the first target coupled to the second target through the ring, and the second target coupled to the master through the ring. The method and apparatus also include a method of using the configuration ring including originating a packet, passing the packet, decoding the packet, and utilizing the packet.

Abstract: The present invention provides a protection protocol for fault recovery, such as a ring wrap, for a network, such as a two line bi-directional ring network. An embodiment of the present invention works in conjunction with a ring topology network in which a node in the network can identify a problem with a connection between the node and a first neighbor. The present invention provides 1 protection protocol which simplifies the coordination required by the nodes in a ring network. The nodes do not need to maintain a topology map of the ring, identifying and locating each node on the ring, for effective protection. Additionally, independently operating ring networks can be merged and the protection protocol will appropriately remove a protection, such as a ring wrap, to allow the formation of a single ring.