2775 results about "Ring network" patented technology

A network adapter for a synchronous logical ring network operates on existing physical twisted-pair telephone topologies. Information propagates around the logical ring, reaching every device on each revolution around the network. Network devices are full-duplex, transmitting and receiving information on every clock cycle. Network devices arbitrate to be elected the network clock device. By synchronizing all network devices to a single reference clock, and providing fixed frames of information propagating around the network at consistent time intervals, the logical ring network ensures that information propagates from one device to another at consistent time intervals. The fixed-length frames are divided into two independent streams: a data stream for the distribution of real-time continuous digital media streams; and a system command stream for the distribution of system commands.

A data relay apparatus stores identification information for identifying itself. A blocking unit blocks a port to avoid an occurrence of a loop path if the data relay apparatus is a master node, and blocks a port connected to a link of the data relay apparatus if a failure occurs to the link. When the link is restored from the failure, a comparing unit compares identification information of other apparatus connected to the link, with the identification information stored. Based on a result of the comparison, a determining unit determines whether the data relay apparatus should be set as a master node.

A load balancing method and apparatus are provided, by which loads in a wide range of the entire system can be balanced with a small overhead with respect to load balancing processing, and the mean response time of the entire system can be shortened. The method has the steps of (i) estimating a load of the present node based on the number of tasks being or waiting to be processed and determining an estimated load value of the node; (ii) accepting a task passing through a logical ring network, and every time a task is accepted, comparing the estimated load value and a threshold value which is set with respect to the number of tasks existing in the node so as to limit the load of the node; and (iii) judging, based on a result of the comparison, whether the accepted task is handed over to a task processing unit, or is transmitted to the logical ring network again without handing over the task to the task processing unit. The threshold value may be changed in accordance with a change of the number of tasks passing through the logical ring network during a fixed period, or when a round trip task is detected.

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.

This invention discloses a kind of fast looped network protection method. It concludes: the fast looped network protection area is set up. Nodes are connected with each other through ports to form a loop. Each node is consisted with two ports that are connected with loop; master node sets the first port to retransmission mode and sets the second port to blocking mode; the link trouble is acquired through accessing control table, retransmission table entry or virtual local area network. The said virtual local area network retransmits data messages and protocol messages; when acquiring the link trouble, master node sets the second node to retransmission mode. The retransmission tables of master node and other nodes are refreshed. A special control VLAN aiming at protocol message does not need. Thus, it can save VLAN ID resource of each node.

A network managing apparatus is connected to one of multiple OADM nodes that execute optical communication on an optical ring network configured by a two-line transmission path including of an active line and a backup line. The apparatus includes a storing unit that stores arrangement information of the OADM nodes and operating wavelength information of optical signals transmitted by the nodes. A controlling unit updates the operating wavelength information retained in the storing unit based on fault information from the OADM nodes and distributes the updated operating wavelength information to the OADM nodes.

An optical fiber ring network includes a plurality of interconnected nodes, each pair of neighboring nodes being interconnected by a pair of optical links. Using coarse wavelength division multiplexing, data is transmitted in both directions over each link, using a first wavelength λ1 to transmit data in a first direction over the link and a second wavelength λ2 to transmit data in a second, opposite direction over the link. The two wavelengths λ1 and λ2 differ by at least 10 nm. Each of the data streams transmitted over the optical link has a bandwidth of at least 2.5 Gbps. Further, each data stream has at least two logical streams embedded therein. A link multiplexer at each node of the network includes one or more link cards for coupling the link multiplexer to client devices, and one or more multiplexer units for coupling the link multiplexer to the optical links. Each link card includes frame buffers capable of storing numerous Fiber Channel frames that are being transmitted to and from the client device(s) coupled to that link card. The link card also includes flow control logic for pre-filling the frame buffers with frames of data before the receiving client devices send flow control messages to request their transmission. The combined effect of the frame buffers and flow control logic is that the full bandwidth of the links can be utilized even when the network nodes are very far apart and the client devices have small input data buffers.

A node includes a manager configured to manage the hash value of the node and the hash values of adjacent nodes, and a calculator configured to calculate an insertion position of a new entry node in a ring network, based on the hash value of the new entry node, the hash value of the node and the hash values of the adjacent nodes.

A fiber optic network transmits data between a hub node and a plurality of local nodes connected by at least one unidirectional fiber ring. Downstream data streams are carried on wavelength-division-multiplexed optical carriers from the hub node to the local nodes. An optical carrier corresponding to a specific wavelength carries downstream data streams to a specific local node. Downstream data streams are multiplexed onto an optical carrier via orthogonal frequency division multiplexing. A parallel signal detector in each local node detects all downstream optical carriers. A signal processing module demultiplexes the data stream from the optical carrier having the specific wavelength corresponding to the local node. An upstream data stream is multiplexed via orthogonal frequency division multiplexing onto an upstream optical carrier having the same specific wavelength and transmitted from the local node to the hub node. Upstream data awaiting transmission is allocated to specific subcarriers and time slots.

This invention discloses a ring network and a method for implementing the service thereof. The ring network includes multiple nodes in a same logic layer for accessing a service to the ring network or receiving a service from the ring network; two virtual channels of reverse directions, which connect the adjacent nodes and are utilized to bear and adapt service data; a physical link, which is utilized to bear the service data adapted to the virtual channel. The method includes the steps of configuring virtual channels at the nodes to form an eastward and westward bidirectional ring network; establishing service Label Switching Path schedules at the nodes; determining a service sink node according to the Label Switching Path schedule at a service source node; dispatching services up to the ring network according to a predetermined algorithm; multiplexing the services of different nodes in a same virtual channel for transmission in the way of Label Switching Path; dispatching the services down the ring network at the service sink node.

A plurality of nodes are connected to one another so as to form a ring network. A pseudo master node blocks relay of user data on one side, and transmits in the ring network a health packet that contains information about a priority order in which the pseudo master node is to be set as a master node. If the pseudo master node receives the health packet transmitted by it, or receives a health packet transmitted by another node, the pseudo master node judges whether the pseudo master node is to be set as a master node based on the priority order contained in the received health packet.

Disclosed is a method for dynamically and losslessly adjusting bandwidth of an embedded Resilient Packet Ring (RPR) ring network, in which dynamic and lossless bandwidth adjustment for an RPR ring network embedded in a Synchronous Digital Hierarchy (SDH) / Synchronous Optical Network (SONET) can be realized through adding a Link Capacity Adjustment Scheme (LCAS) system in the SDH / SONET processing layer. When it is required to increase ring network bandwidth, the bandwidth of the link section between sites on the SDH / SONET processing layer is first increased. Then the LCAS system in the SDH / SONET processing layer is started, and the actual bandwidth of the link on the SDH / SONET processing layer is increased losslessly with the LCAS system. Finally the bandwidth of the ring network on the RPR processing layer is increased. When it is required to decrease ring network bandwidth, the bandwidth of the ring network on the RPR processing layer is first decreased. Then the LCAS system in the SDH / SONET processing layer is started, and the actual bandwidth of the link on the SDH / SONET processing layer is decreased losslessly with the LCAS system. Finally the bandwidth of the link section between sites on the SDH / SONET processing layer is decreased. With the disclosed method, dynamic and lossless bandwidth adjustment for an embedded RPR ring network in SDH / SONET can be realized.

Among networks of ring configuration, the dual ring topology with source steering or wrapping capabilities offers numerous advantages over a single ring topology. In the management of a ring network, problems consist in making sure that every node in the ring is aware of the current ring topology. If, however, two or more links fail even in a dual ring network, the propagation of discovery packets is not guaranteed. A new topology discovery technique is disclosed. In accordance with one aspect of the invention, the algorithm uses only one discovery packet format and a set of timers for a variety of actions to be performed at each node on the ring. The protocol finds valuable applications in RPR and many similar network architectures.

A method and system for implementing weighted fair flow control on a metropolitan area network. Weighted fair flow control is implemented using a plurality of metro packet switches (MPS), each including a respective plurality of virtual queues and a respective plurality of per flow queues. Each MPS accepts data from a respective plurality of local input flows. Each local input flow has a respective quality of service (QoS) associated therewith. The data of the local input flows are queued using the per flow queues, with each input flow having its respective per flow queue. Each virtual queue maintains a track of the flow rate of its respective local input flow. Data is transmitted from the local input flows of each MPS across a communications channel of the network and the bandwidth of the communications channel is allocated in accordance with the QoS of each local input flow. The QoS is used to determine the rate of transmission of the local input flow from the per flow queue to the communications channel. This implements an efficient weighted bandwidth utilization of the communications channel. Among the plurality of MPS, bandwidth of the communications channel is allocated by throttling the rate at which data is transmitted from an upstream MPS with respect to the rate at which data is transmitted from a downstream MPS, thereby implementing a weighted fair bandwidth utilization of the communications channel.

In node devices composing a ring network connected to another network with a redundant node device, a topology table includes redundancy information of the redundant node device, a transmitter transmits topology information and the redundancy information of the node devices themselves, a topology table preparing portion prepares a topology table based on redundancy information and topology information received from the redundant node device, and topology information received from the other node device, and a packet distributor distributes a packet received over the ring network based on the topology table.

Provided is a protection switching method via forwarding table correction in an Ethernet ring network. Upon detecting a failure in a link, a node generates a protection switching frame including an address list of a forwarding table corresponding to a port connected to the link, and transmits the protection switching frame to a port at an opposite direction of the link. A node that receives the protection switching frame deletes its own address from the address list included in the protection switching frame, and changes a port number of an address in the address list of the protection switching frame from among addresses of the forwarding table corresponding to a port that received the protection switching frame to a port number in an opposite direction of the port that received the protection switching frame or deletes the port number of the address in the address list.

The disclosure relates to apparatus and methods that provide a system interconnect for transporting cells between nodes on a dual counter-rotating ring network, including a link selection register for selecting the shortest path to a destination node, use of a fault tolerant frequency reference to synchronize node clocks, interconnect initialization, multi-ring topologies along with an addressing schema and ring-to-ring couplers. The disclosure also discusses flow control of cells leaving nodes, coupling cells from one ring to another, and use of such an interconnect as a bus replacement.

A system to provide fractional bandwidth data transmission includes a network processor, physical layer device, or link layer device {“data device”) and a plurality of link layer devices that are coupled to a plurality of input-output ports. The link layer devices are coupled in a serial daisy chain fashion and pass data via a plurality of data channels. The first linked layer device is coupled to the data device and receives data therefrom and the last linked layer device is coupled to the data device and transmits data thereto forming a ring network that includes all of the link layer devices and the data device. Data received from the data device is contained in data packets that contain a destination identifier and the data. Each link layer device receives input data packets and separates the data packets based on the destination identifier contained therein. Data packets having a destination identifier corresponding to one of the plurality of input-output ports coupled to that particular linked layer device are diverted to the identified input-output port. The remaining data, and any data generated by that link layer device, is provided to the next adjacent down-stream link layer device. Data flow control is provided in an upstream direction from one link layer device to the next adjacent up-stream link layer device as a plurality of status indicators that correspond to the plurality of data channels. Each link layer device is responsive to the plurality of status indicators by not transmitting data on data channels having a corresponding status indicator indicative that no data is to be transmitted.

The invention realizes defect indication on a multipoint logical path and switching of the logical path when the multipoint logical path is configured using a transfer protocol of configuring a logical path, typified by MPLS etc., in a ring network. Two routes of the multipoint logical paths, a working path and a backup path, are set up. Each of them not only transmits a frame transmitted from a transmitting end node to multicast receiving end nodes but also forwards the frame to the transmitting end node and terminates it also at the transmitting end node after making it go around the ring. Any node that detects a defect transmits a forward defect indication frame to a multipoint logical path in which the defect occurs. The transmitting end node having received the forward defect indication frame halts the use of the notified multipoint logical path, and transmits a frame in another path in which the forward defect indication frame is not received within a fixed time period. Moreover, when the forward defect indication frame is received from the both multipoint logical paths, the transmitting end node copies the frame and forwards them to the both multipoint logical paths.

Apparatus and methods relating to bonded interconnection of local communication networks are disclosed. Bonded communication links, including multiple constituent links that have been bonded together, are terminated to enable communications over the bonded links using bandwidth available on the constituent links. A cross-connect function determines whether received communication traffic is to be forwarded to one or more of a local communication network and the terminated bonded links. The received communication traffic is forwarded in accordance with the determination. The local communication networks may include ring networks, linear networks, or both. The bonded links and links between nodes in a local communication network are bonded DSL (Digital Subscriber Line) links in some embodiments. Bonding of DSL links in this manner can be used, for instance, to extend the reach of DSL service without sacrificing bandwidth.

A network includes a plurality of redundant nodes and ordinary nodes. A first redundant node from among the redundant nodes sets a common address and setting information in a message packet and broadcasts the message packet over the network. The common address is commonly used by all the redundant nodes on the network. The setting information is indicative of the fact that the first redundant node is a redundant node. All the nodes have a topology table. The nodes that receive the message packet set in their topology table information indicating of presence of the first redundant node and the common address shared by the redundant nodes. When transmitting a packet to the first redundant node, a node sets the common address as a destination address of the packet.

The invention discloses a comprehensive monitoring system of a power distribution network based on the internet of things and an intelligent patrol robot. The system comprises a monitoring system, an intelligent patrol robot, a background management platform and a remote receiving terminal. The monitoring system comprises an environment monitoring system, an anti-theft monitoring system, a fire-fighting monitoring system, an entrance guard management system, a ring network cabinet monitoring system and a related linkage device. The monitoring system is in communication connection with the background management platform through an intelligent acquisition device. The background management platform sends out a control instruction and controls the working state of the related linkage device through the intelligent acquisition device. The intelligent patrol robot and the remote receiving terminal are in communication connection with the background management platform. According to the technical scheme of the invention, the intelligent routing inspection of a substation and the centralized monitoring and management of an on-site environment, anti-theft equipment, fire-fighting equipment and a ring main unit are realized. Therefore, the linkage device is intelligently controlled, and potential fault risks are prevented in advance. Moreover, an occurred fault can be quickly and accurately judged and treated. Therefore, the safe and stable operation of the power distribution network is ensured.

A method for operating a ring network includes the steps of configuring the ring network with static configuration information and then deterministically exchanging operational data between a plurality of nodes on the ring network, while operating the ring network in accordance with the static configuration information. This system facilitates communications that meet the high reliability and performance requirements of vehicle communications, in particular in aircraft data networks (ADNs), while reducing the cost, weight, and complexity of conventional implementations.

An optical network terminator for terminating and reducing the accumulated noise in optical networks, particularly ring based networks. The terminator eliminates problems of noise accumulation from amplifier spontaneous emission (ASE), thermal noise, etc., while providing bi-directional communications in the optical network. The optical network may have any topology including ring, star, mesh, point-to-point, etc. In the case of an optical ring, the ring is broken and an optical terminator is placed in line therewith. The optical network terminator includes a filer such as an optical demultiplexer / multiplexer or Fiber Bragg Grating (FBG) based filter. Each individual wavelength of light is filtered and a multi-wavelength optical output is generated whereby the noise accumulation is removed. Each channel is adapted to only pass a band-limited signal around the center frequency corresponding to the wavelengths supported by the particular optical ring network. Channel equalization uses variable optical attenuators and monitors in line with each channel. Channels currently not in use may be disconnected from the ring remotely by setting the corresponding optical attenuator to a low enough level.

The invention discloses a ring redundant real-time Ethernet communication method which is characterized in that chain networks are compatible with each other through a communication terminal node automatic arbitration mechanism, the effect caused by false code transmission is reduced in a manner of transmitting redundant data, the normal operation of two chain network maintenance systems can be automatically formed after intermediate network disconnection or node failure, so that the reliability of the systems is greatly improved. The network at least contains a main node and a plurality of slave nodes; each node is provided with a standard Ethernet network interface A and a standard Ethernet network interface B; a network cable starts from the network interface A of the main node, connects all the slave nodes together in a cascading manner and is finally connected with the network interface B of the main node to form a ring network loop; a ring network is compatible with a chain Ethernet by adopting a terminal slave node automatic arbitration mechanism and realizes self-recovery after network disconnection; and the whole communication process is divided into three stages, i.e. enumeration, configuration and cyclic communication. According to the situation that the network disconnects from the middle part due to failure, the systems automatically and continuously keep the communication with the main node according to the two chain networks, thereby enhancing the reliability and the fault-tolerant ability of the systems.

An autoprotected optical communication ring network includes a first and a second optical carrier having opposite transmission directions and a plurality of optically reconfigurable nodes optically connected along the first and the second optical carrier and adapted to communicate in pairs on links susceptible to failure, the ring network having a normal operative condition in which the nodes of each pair are optically configured so as to exchange optical signals on a working arc path at a respective first wavelength (λx) on the first carrier and at a respective second wavelength (λy) different from the first wavelength (λx) on the second carrier, the working path having a complementary arc path defining a protection arc path in which the first wavelength (λx) on the first carrier and the second wavelength (λy) on the second carrier can be used for further links.

A method in a network device configured in a true ring network where the network device has a first port and a second port connected to the true ring network and a third port connected to a processor including: connecting the network device to transmit data packets in a single direction around the true ring network including an ingress port and an egress port; enabling ingress tag VLAN filtering on the ingress port only; configuring a VLAN table in the network device to terminate an incoming data packet when a VID tag (VLAN identifier tag) of the incoming data packet matches the local VID tag of the network device; and configuring the VLAN table in the network device to accept the incoming data packet when the VID tag of the incoming data packet does not match the local VID tag of the network device.

The invention is used in ring networks crossed each other (N is a natural number and is greater than or equal 2); wherein, the one is main ring and the N-1 are sub-rings; each ring network only has a main node. The method comprises: when the assistant edge node detects that protocol message channel of sub-ring on the main ring is interrupted, after it receives the notice from the assistant edge node through the edge port, the edge node blocks the edge port, and informs the sub-ring that the edge port of main node is blocked, and indicates the main node of sub-ring to open the standby port. The invention also opens a system and a network apparatus thereof.