Abstract: A method and system for providing a multi-level interconnection network is provided. A multi-level interconnection network comprises basic cells that are aggregated into higher level cells at each level of the network. At the first level, the basic cells are aggregated into first level cells. Each first level cell is an aggregation of a number of basic cells that is one more than the number of devices in a basic cell. The basic cells of a first level cell are fully connected; that is, each basic cell has a first level link or connection to each other basic cell. In a first level cell, each device of a basic cell has a first level link to each other basic cell. The multi-level interconnection network has higher level cells that are aggregations of lower level cells in a similar manner.

Abstract: Techniques are described for providing hybrid forwarding within an Ethernet-based service domain established over one or more intermediate networks, such as a service provider (SP) network. For example, the Ethernet-based service domain may comprise a virtual private local area network service (VPLS) domain. A hybrid VPLS domain may transport layer two (L2) communications, such as Ethernet packets, between remote customer networks via the SP network. The techniques described herein enable a network device, e.g., a router, within a SP network to forward packets from a source device of a hybrid VPLS domain toward one or more subscriber devices of the hybrid VPLS domain (i.e., in a downstream direction) using P2MP forwarding semantics. The same network device forwards packets from one of the subscriber devices toward the source device (i.e., in an upstream direction) using P2P forwarding semantics.

Abstract: A switch is configured to block packets from being transmitted through designated ports. The switch has port bitmap generator configured to obtain a port bitmap and a table is configured to store a block mask indicating which port the packet should not be transmitted. A block mask lookup is configured to determine the block mask for the packet from the table, and a transmit port bitmap generator is configured to determine which ports the packet should be transmitted using the port bitmap and the block mask.

Abstract: In one embodiment, a method for automatically probing endpoint in a network for performance and fault management is provided. The method may comprise receiving instructions to auto probe endpoints, the instructions comprising probe characteristics and endpoint indicators. The method may further comprise querying an information base to identify endpoints and to obtain information on the identified endpoints that conform to the endpoint indicators. Based on the instructions and the information obtained for the identified endpoints, one or more probe packets may be generating to be transmitted to the identified endpoints. The generated probe packets may further be scheduled for transmission to the identified endpoints. New endpoints may continue to get discovered based on a notification mechanism which exists. Likewise, endpoints leaving the discovery domain may be identified.

Abstract: A computer implemented method and apparatus are provided for transferring data in a logical partitioned data processing system. A receiving adapter receives data from a network. The receiving adapter transfers the data to a pre-mapped buffer if the data is to be sent to a target adapter. A virtual bridge receives the pre-mapped buffer from the receiving adapter and transfers the pre-mapped buffer to the target adapter. The target adapter receives the pre-mapped buffer from the virtual bridge and determines that the received buffer is pre-mapped. The target adapter accesses the pre-mapped buffer using pre-mapped mapping, and transmits the data contained therein.

Abstract: The Fibre Channel Credit Extender (FCCE) (600) is a network device that is disposed between and connected to an end node (210) and an optical repeater (220). The FCCE (600) contains as many buffer credits as necessary, to solve bandwidth problems in a network. In a situation where maximum bandwidth is required in both directions of a link, the FCCE (600) breaks a single logical link into three physically separated “linklets.” The short-distance linklets attain maximum bandwidth by use of the existing buffer credits of the end nodes. The long-distance linklet attains maximum bandwidth by use of very high receive buffer credits in the FCCEs (600). In this way, only those links that need maximum bandwidth over distances not covered by end-node credit counts need be attached to an FCCE (600). The FCCE (600) contains the optical repeater to gain distance on that link, and contains high credit count receive buffers to gain bandwidth on the link.

Abstract: An integrated circuit device for use in connecting synchronous optical networks to packet networks and synchronous time division multiplexed subscriber lines and a method of operation of same is disclosed. An embodiment of the invention may include SONET/SDH compatible optical carrier framing, cross connect, and packet mapping functionality. In addition, it may support Ethernet packet network connections and DS1/E1 and DS3/E3 time division multiplexed subscriber circuits, and may include a telecom bus compatible interface for the connection of additional communications devices. An embedded microprocessor core and embedded memory may permit the present invention to support enhanced remote diagnostic, trouble reporting, traffic management, and software update capabilities.

Abstract: An ad hoc network with distributed hierarchical scheduling is disclosed. In one aspect, stations in a network mesh detect interfering neighbor stations and form interference lists. Stations transmit their interference lists. Scheduling stations schedule allocations for child stations in response to interference lists, received remote allocations, or a combination thereof. Coordination messages are transmitted including frame structure, allocations, and interference lists, among others. In another aspect, an ad hoc mesh network may be organized into a tree topology. In an example wireless backhaul network, this matches traffic flow. Distributed, hierarchical scheduling is provided where parents schedule communication with children while respecting already scheduled transmissions to/from interferers and to/from interferers of their respective children.

Abstract: This disclosure concerns transceivers that include CDR bypass functionality. In one example, a 10 G XFP transceiver module includes integrated CDR functionality for reducing jitter. The 10 G XFP transceiver module also implements CDR bypass functionality so that the CDR can be bypassed at rate less than about 10 Gb/s, such as the Fibre Channel 8.5 Gb/s rate for example.

Abstract: The Fibre Channel standard was created by the American National Standard for Information Systems (ANSI) X3T11 task group to define a serial I/O channel for interconnecting a number of heterogeneous peripheral devices to computer systems as well as interconnecting the computer systems themselves through optical fiber and copper media at gigabit speeds (i.e., one billion bits per second). Multiple protocols such as SCSI (Small Computer Serial Interface), IP (Internet Protocol), HIPPI, ATM (Asynchronous Transfer Mode) among others can concurrently utilize the same media when mapped over Fibre Channel. A Fibre Channel Fabric is an entity which transmits Fibre Channel frames between connected Node Ports. The Fibre Channel fabric routes the frames based on the destination address as well as other information embedded in the Fibre Channel frame header. Node Ports are attached to the Fibre Channel Fabric through links.

Abstract: The Fibre Channel standard was created by the American National Standard for Information Systems (ANSI) X3T11 task group to define a serial I/O channel for interconnecting a number of heterogeneous peripheral devices to computer systems as well as interconnecting the computer systems themselves through optical fiber and copper media at gigabit speeds (i.e., one billion bits per second). Multiple protocols such as SCSI (Small Computer Serial Interface), IP (Internet Protocol), HIPPI, ATM (Asynchronous Transfer Mode) among others can concurrently utilize the same media when mapped over Fibre Channel. A Fibre Channel Fabric is an entity which transmits Fibre Channel frames between connected Node Ports. The Fibre Channel fabric routes the frames based on the destination address as well as other information embedded in the Fibre Channel frame header. Node Ports are attached to the Fibre Channel Fabric through links.

Abstract: A VoIP system has a VoIP server and plural clients. The client transmits paging data as multicast packets addressed at a specific multicast address, to other clients. In response to a request from the client, the VoIP server transmits multicast packets of MOH data to the other clients. At this time, whether the other clients can receive multicast packets is determined. To the clients that are determined to be capable of receiving multicast packets, transmission data is sent in the form of multicast packets. To the client which belongs to a router and is determined to be incapable of receiving multicast packets, the transmission data is sent as unicast packets. It is thus possible for the VoIP system to support paging and MOH in the form of multicast packets, with respect to clients incapable of receiving multicast.

Abstract: Publish-subscribe XML multicast service within a VPN service is described. A backbone such as an IP/MPLS backbone connects multiple subscriber sites using VPN technology and VPN edge routers. XML publish-subscribe modules are addressable within the VPN and form an overlay network between the edge routers participating in the VPN. The XML publish-subscribe modules may perform either topic-based multicast or content-based multicast services. The multicast service is self-managed.

Abstract: An apparatus, system, and method are disclosed for automatically and transparently managing addresses in an arbitrated loop network. An arbitrated loop network switch is programmed with an address map and configured with the necessary modules to monitor an address assignment process and associate soft assigned addresses claimed during the address arbitration process with physical slot addresses. In one embodiment, the address fields of packets addressing a specific physical slot are changed (in route) to the soft address assigned during the address arbitration process. The entire process may be transparent to the rest of the network and to users. The present invention facilitates maintaining a physically ordered addressing scheme despite any soft addressing that occurs during loop initialization.

Abstract: A data transmission apparatus used in a multiple service ring includes at least two nodes coupled to at least one aggregate pipe and at least one tributary. The data transmission apparatus includes a tributary RX framer coupled to a tributary for deframing data frames received from the tributary and extracting a destination node address and a TX framer for encapsulating the destination node address and the data received from the tributary into frames of the multiple service ring and transmitting the same along an aggregate pipe to a downstream neighbor node in the ring.

Abstract: In receiving a MAC (media access control) frame whose destination address is any of a broadcast address, an unknown multicast address and an unknown unicast address, the flooding is reduced by broadcasting the received MAC frame to all the other ports than one that has received the MAC frame. An output control that attains this object is realized by using a destination group identifier (ID) look-up table (2-T1) which enables a look-up of a destination group ID by using, as a key, any one or combination of header information of the MAC frame, a port which received the MAC frame and a service VLAN (virtual local area network) ID corresponding to the MAC frame and a backbone port look-up table (2-T2) which enables a look-up of at least one backbone port which is to transmit or at least one backbone port which is not to transmit by using the destination group ID as a key.

Abstract: A network architecture for implementation in a vehicle is described that comprises an Ethernet gateway module (EGM) and network interface module (NIM). The EGM comprises an Ethernet switch and router therein and is configured to provide an open data network (ODN) connection to the network architecture for a plurality of open data network devices. The NIM is configured to provide an isolated data network and comprises an Ethernet switch to connect a plurality of secure devices to an isolated data network (IDN), the secure devices related to operation and navigation of the vehicle, a router and a gateway/router. The router is configured to interface the IDN to the open data network connections and comprises a packet filtering function to determine which, if any, data from the ODN may be passed through to the IDN and applied to operation and navigation of the vehicle via the secures devices connected to the IDN.

Abstract: A system, method, and computer-readable medium for performing network system diagnostics is provided. The method includes obtaining a respective identification of a first target device and a second target device deployed in a network; iteratively querying neighbor devices of at least one node in a communications path between the first and second target devices, wherein the neighbor devices and the first and second target device may comprise heterogeneous network nodes; and generating a layer 2 path trace that comprises identification of network devices interconnected on a physical path between the first and second target devices. A computer-readable medium includes instructions for execution by a processing system, wherein the instructions are configured to perform the foregoing method. A system includes a data processing system including a processor device for executing a diagnostics engine implemented as a set of computer-executable instructions configured to perform the foregoing method.

Abstract: An integrated circuit device for use in connecting synchronous optical networks to packet networks and synchronous time division multiplexed subscriber lines and a method of operation of same is disclosed. An embodiment of the invention may include SONET/SDH compatible optical carrier framing, cross connect, and packet mapping functionality. In addition, it may support Ethernet packet network connections and DS1/E1 and DS3/E3 time division multiplexed subscriber circuits, and may include a telecom bus compatible interface for the connection of additional communications devices. An embedded microprocessor core and embedded memory may permit the present invention to support enhanced remote diagnostic, trouble reporting, traffic management, and software update capabilities.

Abstract: In one embodiment, a node comprises an interface to communicatively couple the node to a channel. The channel communicatively couples the node to a first neighbor node in a first direction and to a second neighbor node in a second direction. When the first neighbor node is scheduled to transmit and the node receives data from the first neighbor node via the channel, the node determines if the transmission of the data complies with a policy. When the transmission of the data does not comply with the policy, the node does at least one of: blocks the data from being relayed along the channel and relays the data along the channel with information indicating that the transmission of the data does not comply with the policy.

Abstract: A relay unit capable of inquiring of a DNS comprises: an inquiry section which transfers an acquisition request of a transmission destination terminal address, sent from a transmission source terminal, to the DNS, and acquires the transmission destination terminal address and a transmission destination label corresponding to the transmission destination terminal address and transmission destination terminal; a label creation section which creates a unique relay label; a label storage section which correlates the created relay label to the acquired transmission destination terminal address and transmission destination label, and stores thus obtained label; a label transmission section which transmits the relay label and a private address of the relay unit to the transmission source terminal; and a determination section which, if a packet containing the relay label is received from the transmission source terminal, determines that the transmission destination terminal address and transmission destination label

Abstract: Embodiments of the present invention provide a system and method for handling persistent reservations. More particularly, according to one embodiment of the present invention, a routing device that routes commands from multiple initiators to a target device can assert reservations for the initiators using its own reservation key rather than a reservation key provided by an initiator. The routing device can further maintain a registry of keys for multiple initiators that access the target device through the routing device. For a persistent reservation command received using a persistent reservation key in the registry, the routing device can forward the command to the target device server using the routing device's key. Thus, reservations for the multiple initiators will be held using the routing device's key. For persistent reservation commands received from initiators registered with the routing device, the routing device can handle conflict resolution and other persistent reservation processing.

Abstract: A method for communication is used in a communication network that includes multiple ring nodes arranged in at least first and second ring networks, which are connected by one or more of the ring nodes serving as interconnect nodes. A data packet is accepted from a source user node served by the first ring network, for forwarding to a destination user node served by the second ring network. An identifier, which identifies an interconnect node in the first ring network through which the data packet is to be forwarded to the second ring network, is attached to the data packet in the first ring network. The data packet is forwarded over the first ring network, accepted at the interconnect node and, responsively to the identifier, forwarded from the interconnect node to the second ring network. The data packet is forwarded over the second ring network to the destination user node.

Abstract: The invention discloses a method for dynamically allocating link bandwidth on resilient packet ring. This algorithm comprises the steps of measuring a group of variables in one advertisement interval, calculating the local fair rate using the measured variables, determining an advertising rate based on the local fair rate, and transmitting the data packets with the advertising rate. Compared with existing fairness algorithms, the new algorithm introduces integration for the idle rate to achieve 100% of bandwidth utilization. It also avoids using the concept of “congestion state” which is essential in the existing fairness algorithm.

Abstract: A method and system for designing a bi-connected ring-based network is provided, which designs from scratch or converts an existing network to a dual-homed ring-based network. The network covers the locations capable of being bi-connected with one or more cycles/rings. The traffic demand is then routed via the cycles, in such a way so as to minimize the amount of network traffic management equipment required.

Abstract: Methods and apparatus for switching Fiber Channel Arbitrated Loop Systems is provided between a plurality of Fiber Channel Loop devices. In one aspect of the invention, the system switches based at least in part on arbitrated loop primitives. An exemplary interconnect system may include a first port and a second port, both including port logic to monitor certain arbitrated loop primitives, a connectivity apparatus, a route determination apparatus including a routing table consisting of ALPA addresses and their associated ports, the route determination apparatus coupled to each port and the connectivity apparatus, where the connectivity apparatus creates paths between the ports based on arbitrated loop primitives. In one embodiment, the connectivity apparatus is a crossbar switch. Examples of the arbitrated loop primitives that cause the switch to create paths between ports includes one or more of the following: ARB, OPN and CLS.

Abstract: In one embodiment, a node comprises an interface to communicatively couple the node to a first channel. The first channel communicatively couples the node to a first neighbor node and a first neighbor's neighbor node in a first direction. When the node is operating in an unsynchronized mode: the node relays, along the first channel, for a relay period, data received from the first neighbor node that was sourced from that first neighbor node and, after relaying the data received from the first neighbor node that was sourced from that first neighbor node and for a block period, the node blocks data received from the first neighbor while the node relays, along the first channel, data received from the first neighbor's neighbor node.

Abstract: The present invention discloses novel network architectures for evolving traditional service provider networks. The network architecture of the invention has a transport layer including an optical network. At least one node of the network architecture includes a large packet switch that is coupled to the transport layer and to an access layer. The large packet switch aggregates a plurality of services from the access layer. The large packet switch also performs packet level grooming of the information from the services prior to transport of the information via the transport layer. The optical network performs restoration for the network architecture. In one embodiment, the optical network is an optical ring network including at least one optical switch and restoration is performed at the layer-0 (optical layer).

Abstract: A method and system for routing fiber channel frames using a fiber channel switch element is provided. The switch element includes, a hashing module whose output is used to select the column from a look up table to route frames. The method includes, indexing a look up table using domain, area, virtual storage area network identifier, a hashing module output and/or AL_PA values; selecting a column from the look up table based on a column select signal; and routing a frame if a route is valid. The hashing module takes a fiber channel header to generate a pseudo random value used for selecting a column from the look up table. The hashing module uses same field values in an exchange to generate the pseudo random value. A hash function is used on a frame's OX_ID, D_ID, S_ID, and/or RX_ID to route fiber channel frames.

Abstract: A method of encapsulating data packets for use in a distributed computer network is disclosed. The method includes providing a data packet for transmission over the distributed computer network, the data packet selected from one of a customer data packet and an OAM data packet; and encapsulating the data packet with a medium access control outer packet. The disclosed data packet handling method includes receiving a data packet from a customer facing data port, the customer facing data port within a network node of a computer network; performing medium access control (MAC) learning for the received packet; determining whether the data port is a MAC-in-MAC port; performing a packet mapping to a destination address based on a service provider destination address; and encapsulating the received data packet with a header associated with the service provider.

Abstract: A plug-in card for an optical transmission apparatus includes a J1generating unit. The J1 generating unit sends information on on-use side J1 data to a plug-in card at a spare side in a redundant structure when the plug-in card operates as an on-use side plug-in card. The J1 generating unit receives information on on-use side J1 data from a plug-in card at the on-use side when the plug-in card operates as a spare side plug-in card. Based on the information, the J1 generating unit matches spare side J1 data to the on-use side J1 data. The plug-in card also includes a B3 byte calculating unit that operates in a similar way as the J1 generating unit does in processing B3 byte data.

Abstract: A transmitter forms each subcarrier group of only frequency locations of subcarriers to which at least one pilot signal is allocated, and conducts transmission by allocating a macro-diversity signal into the subcarrier group and allocating a non-macro-diversity signal to other frequencies (outside the subcarrier group). As for the macro-diversity signal, a receiver conducts channel estimation on the basis of the pilot signal in the same subcarrier group as the macro-diversity signal. As for the non-macro-diversity signal outside the subcarrier group, the receiver conducts channel estimation on the basis of the pilot signal, and results of channel estimations of the macro-diversity signal and other non-macro-diversity signals.

Abstract: A relay device 10 is a relay device for relaying a communication message on a packet-by-packet basis, which comprises an order determiner 13 for determining whether a packet received is one received in an order to be received, a packet holder 14 for, when it is determined that the packet is not one received in the order to be received, holding the packet, and for performing such a control as to relay the packet, a merger 15 for merging a payload of the received packet with a payload of the held packet, a verifier 16 for verifying whether a payload of a packet satisfies a predetermined rule, and a relay controller 17 for, when a packet satisfies the rule, performing such a control as to execute relay of the packet. This prevents an increase of a communication delay and enables detection of an irregular communication message in an application layer protocol, irrespective of types of protocols.

Abstract: Methods and apparatus for switching Fiber Channel Arbitrated Loop Systems is provided between a plurality of Fiber Channel Loop devices. In one aspect of the invention, the system switches based at least in part on arbitrated loop primitives. An exemplary interconnect system may include a first port and a second port, both including port logic to monitor certain arbitrated loop primitives, a connectivity apparatus, a route determination apparatus including a routing table consisting of ALPA addresses and their associated ports, the route determination apparatus coupled to each port and the connectivity apparatus, where the connectivity apparatus creates paths between the ports based on arbitrated loop primitives. In one embodiment, the connectivity apparatus is a crossbar switch. Examples of the arbitrated loop primitives that cause the switch to create paths between ports includes one or more of the following: ARB, OPN and CLS.

Abstract: A method and system for providing harmonized public security and safety services to multiple public security and safety control centers, the public security and safety control centers being adapted to control terminals over at least one access communication network. The method includes the following steps: providing multiple public security and safety control centers access to a service platform, with the service platform containing an application server layer and a communication layer; upon service request of one of the public security and safety control centers, executing a corresponding application on the application server layer of the service platform, the application generating at least one command to be executed in one of the access communication networks; forwarding the command said the communication layer to the appropriate gateway and executing the command in the access communication network.

Abstract: A virtual ring representing a community of interest is constructed from an interconnected mesh of nodes in a packet network. The virtual ring instantiates ring labels in respective forwarding tables for each node in the virtual ring and then advertises the ring labels to all other nodes in the virtual ring, for example by flooding BGP advertisements. Data packets entering the ring are assigned a ring label which is then stripped off when exiting the ring. The data packets are forwarded around the virtual ring using the ring labels. The virtual ring can operate using BGP/LDP Multi Protocol Label Switching (MPLS). Multiple virtual rings can be bridged together using a central hub or alternatively multiple virtual rings can be redundantly bridged together using tandem hubs.

Abstract: In one embodiment, a node comprises an interface to communicatively couple the node to a channel. The channel communicatively couples the node to a first neighbor node and a first neighbor's neighbor node in a first direction. When the node relays relayed data along the channel, the node compares data received from the first neighbor node with data received from the first neighbor's neighbor node. The relayed data comprises: at least one of: the data received from the first neighbor node and the data received from the first neighbor's neighbor node; and information indicative of the results of the comparison.

Abstract: A transmission apparatus includes an aggregate-side interface unit coupled to an optical transmission line, a cross-connect unit which performs cross-connect with respect to a synchronized digital signal supplied from the aggregate-side interface unit, and a network signal processing unit which switches the synchronized digital signal in a unit of a network signal as the synchronized digital signal is supplied from the cross-connect unit.

Abstract: The distribution of traffic flows in a load-sharing redundancy group that includes a first gateway device and a second gateway device includes assigning a first set of forwarding addresses to the first gateway device and a second set of forwarding addresses to the second gateway device. The redundancy group distributes forwarding addresses to hosts which in turn use the distributed forwarding addresses to send packets to the redundancy group. The traffic flow for each of the assigned forwarding addresses is measured and may be compared to a target traffic flow. The traffic flow is adjusted to close in on the target traffic flow. Adjustment of the traffic flow can be accomplished either by changing the existing measured traffic flow by re-assigning a forwarding address originally assigned to one gateway device to a different gateway device or by altering future distribution of forwarding addresses so that additional traffic is sent to one or more forwarding addresses having lower measured traffic.

Abstract: A communications system comprising a first stage including a first scan table and a second stage including a second scan table. The first stage is configured to select a first channel identification from the first scan table and provide data from a channel identified by the first channel identification. The second stage is configured to receive the data and select a second channel identification from the second scan table to provide the received data at essentially a data rate of the channel on a synchronous network.

Abstract: A flexible cross-connect with a data plane is presented which allows the establishment of connections between network interfaces at any network interface card to another network interface on any other network interface card. The system can cross-connect connections at an STS-1 and VT 1.5 granularity, and allows the switching and routing of information in a data plane without the use of the cross connect fabric. This permits routing, bridging, and concentration of data services to be performed without burdening of the cross connect. For reliability, a range of protection configurations can be employed including 1:1, 1:5 and mixed 1:N protection. A backplane is used which provides point-to-point traces between each card and the cross connect unit, between each card and a timing, communications and control unit, and between the network interface cards themselves.

Abstract: A transceiver module having intergrated eye diagram opening functionality for reducing jitter is describe. The transceiver module may transmitter eye opener and a receiver eye opener integrated in a single circuit. The transceiver module may also include serial control and various other integrated components. Other functionalities that may be integrated on the transceiver module include loopback modes, bypass features, bit error rate testing, and power down mode.

Abstract: The invention provides a method and system for enhancing the capability to optimally route VT circuits over SONET networks. The invention discloses a method for identifying Network Elements (NEs) that have VT capability (i.e., VT cross connect capability) and, when desired or required for VT circuit routing, manually or automatically topologically interconnecting these NEs by STS-1 circuits called VT Tunnels. Once interconnected, these VT Tunnels are suitable for supporting user VT traffic without the network operator being required to upgrade non-VT NE with VT capability or without having to exhaust the limited pool of available VT cross connects on one or more NEs.

Abstract: Described herein are systems and methods in which taps, which mirror or provide a copy of network traffic, are connected to monitoring equipment through shadowing units, which pass data to the monitoring equipment but block outbound data transmissions from the monitoring equipment. Aggregation/dissemination units are provided to aggregate and/or disseminate tapped data network signals to the monitoring equipment. Also disclosed are optional bypass controllers that can either route the tapped data network signals directly to the monitoring equipment or route such signals through the aggregation/dissemination units.

Abstract: When an externally received data frame is transmitted at a station of a ring-shaped packet communication network, a congestion point in the communication network is defined as a boundary point, a frame addressed to a station located before the boundary point is transmitted at a first transfer rate, and a frame addressed to a station located after the boundary point is transmitted at a second transfer rate lower than the first transfer rate.

Abstract: A resilient packet network (RPR) device is connected to one or more rings to constitute an RPR network. The RPR device has a storage unit in which a correspondence between RPR device addresses, each indicating an RPR device connected to the one or more rings, and user device addresses, each indicating a user device accommodated in the RPR device, is stored. When the RPR device receives data addressed to a predetermined user device from a user device accommodated in the RPR device itself, if an RPR device address of an RPR device accommodating the predetermined user device is registered in the storage unit, an RPR header, in which the RPR device address is set as a destination RPR device address, is added to the data. The data with the RPR header is transmitted to the RPR network.

Abstract: A network includes multiple nodes interconnected to form a ring topology. These nodes support data transmissions over the network using tokens. To send and receive data over the network, nodes may process control messages. A node can receive a first token authorizing transmission on one of multiple data channels, generate a transmission control message identifying a destination node and the authorized data channel, and communicate the transmission control message to a next node. The node can also communicate a second token to the next node authorizing secondary transmissions on the authorized data channel, transmit data on the authorized data channel after communicating the transmission control message, and communicate the first token to the next node after communicating the second token to the next node.

Abstract: Determining a frequency and phase offset estimates include receiving a signal at an offset estimator. The received signal is zero-padded in the time domain to yield a zero-padded signal. A Fourier transform of the zero-padded signal is taken to yield a transformed signal. The maximum power of the transformed signal is established. Frequency and phase offset estimates are generated based on the maximum power of the transformed signal.

Abstract: Methods and apparatus for Fiber Channel interconnection is provided between a plurality of private loop devices through a Fiber Channel private loop device interconnect system. In the preferred embodiments, the Fiber Channel private loop device interconnect system is a fabric or an intelligent bridging hub. In one aspect of this invention, a Fiber 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 Fiber Channel frames must attempt to be routed through the fabric. Numerous topologies of interconnect systems may be achieved.

Abstract: In an inter-ring connection method and device interconnecting a plurality of RPR rings, an inter-ring connecting device (interconnecting station) determines whether or not an RPR frame received from one ring is a broadcast frame; and resets, when the RPR frame determined to be the broadcast frame is relayed to another ring, a ttl of the frame so that a predetermined point between the inter-ring connection device itself and another identical inter-ring connection device opposed within a ring to be relayed is a cleave point. Also, topology information of the one ring is transmitted to another ring; topology information of each ring is held in a topology database; and an RPR frame is relayed (unicasted) between the rings by referring to the topology database based on a destination address of the RPR frame.