274 results about "Span tree" patented technology

The invention relates to a power distribution network double layer planning method considering the time sequence and the reliability. The method comprises: according to the meteorological files and the load power statistical data, obtaining the typical daily power time sequence curves of the wind electricity, the photovoltaic output and the load in different seasons; based on the opportunistic constraint planning method, creating a power distribution network framework and a distributed power capacity double layer planning mathematical model, including the objective function and the constraint condition; using the particle swarm optimization algorithm to solve the model and using the minimum spanning tree algorithm to ensure the radiation and connectivity structure of the distribution network during the iterative process; and obtaining the target network framework and the Pareto optimal solution set of the distributed power capacity so as to generate the best planning scheme. The invention solves the problems that unnecessary investment into the a power distribution network incurred by the fact that a traditional power distribution network planning method containing a distributed power supply cannot reflect the typical output characteristic of a distribution type new energy; and 2) that by incorporating the power distribution network power supply reliability into a model target function, the reliability target can be realized at the planning stage.

A method and apparatus for continuing the operation of a spanning tree protocol at a network device despite crashes or failures at that device. A supervisor card contained in the network device is designated an active supervisor, while all other supervisor cards are designated standby supervisors. The active supervisor runs the spanning tree protocol, and informs the standby supervisors of the states of ports, but not of the identity of the root or designated bridges. When a crash or failure occurs at the active supervisor, one of the standby supervisors is immediately designated to be the new active supervisor. The newly active supervisor reviews the port state, and queries the line cards to determine whether that port state information is still valid. The newly active supervisor adopts the valid port state information, leaving those ports in their current spanning tree port state.

A system and method for automatically configuring a network so that each switch in the network is aware of the Multiple Spanning Tree Instances (MSTI) of each other switch and the Virtual Local Area Network (VLAN) that each switch uses. This is achieved through the use of controllers connected to each switch. A master switch is elected and the master switch monitors messages to determine if a switch should be using an alternative MISTI. If so, the master switch instructs a switch to use an alternative MSTI. Either a switch or a node connected to the switch may determine which VLAN to use in sending messages, subject to configuration from the controller of the master switch. Messages are periodically sent by each controller to educate other controllers to aid in learning which node is part of a group connected to a switch, the switch in turn connected to a controller.

A method and human-machine interface for backbone Virtual Local Area Network (VLAN) provisioning in bridged networking environments are provided. The method includes steps of provisioning backbone VLAN support on every backbone data transport trunk and by extension of every stackable data trunk port in the associated data transport network. The human-machine interface enables an operator to expediently effect VLAN provisioning abstracting the intricacies of the data transport network over which VLAN services are provisioned. Advantages are derived from backbone VLAN provisioning independent of an underlying in-use active spanning-tree topology. In particular backbone VLANs are provisioned over spanning-tree stand-by designated backbone data transport trunk links and therefore preprovisioned in the case of spanning-tree re-configuration. Customer VLANs are mapped onto backbone VLANs ensuring data traffic differentiation, and providing standard VLAN identifier portability. Operator VLAN provisioning tasks are lessened via provisions for the selection of all backbone/stackable data transport trunk links/ports in the data transport network in effecting VLAN identifier associations therebetween.

In one embodiment, a method for setting up a flow-through mesh group (FTMG) for transmitting link-state packets (LSPs) in a network having a plurality of nodes interconnected by links. The FTMG is a combination of multiple spanning trees for the network through which LSPs are forwarded. FTMG set-up messages are received at ports of each node of the network from peer ports of linked nodes. FTMG set-up messages identify root nodes of the multiple spanning trees and the transmission modes of the peer ports. The FTMG set-up messages are used to determine (1) a root node for each spanning tree, (2) a root port on each node for each spanning tree, and (3) directionality of ports of the nodes. FTMG set-up messages are then used to determine the transmission mode of ports of the nodes and, subsequently, to update the spanning trees and transmission modes, as needed.

An apparatus for designing a virtual VLAN network includes a database containing data representing a plurality of VLAN networks in a spanning tree topology, each of the VLAN networks being formed of a plurality of VLAN member nodes interconnected by links. In response to a network configuration request from a communications network, control circuitry determines the costs of the links, and then determines least cost unicast paths by using a shortest path algorithm. A search is made through the least cost unicast paths for detecting a loop. If at least one loop is detected, a link of highest cost of the loop is blocked. All unicast paths of the blocked link are reestablished through links that circumvent the blocked link. A spanning tree built up with all the links accommodating the least cost unicast paths is established. Configuration command is sent to the network for configuring it according to the established spanning tree.

Disclosed is a method, apparatus and computer-readable medium for selecting a root bridge when a spanning tree is configured in an Ethernet network including a plurality of legacy switches and a plurality of synchronous switches. The method comprises the steps of providing in advance identification information in a configuration BPDU message of the synchronous switch, the identification information representing that a corresponding switch is an AV switch, broadcasting configuration BPDU messages by the legacy switches and the synchronous switches; and receiving configuration BPDU messages by the synchronous switch from other switches, confirming bridge priorities according to the synchronous switches through the received configuration BPDU message and the identification information to select a synchronous root bridge, receiving configuration BPDU messages by the legacy switch from other switches, and confirming bridge priorities through the received configuration BPDU messages to select a legacy root bridge.

The invention discloses a method and device for searching the shortest path of a road network. The method comprises the following steps of dividing the road network into a plurality of sub-networks to generate the road network with a tree structure; calculating the shortest path between boundary nodes of the sub-networks at the same layer; inputting an enquiry point and a target point; according to the shortest path, implementing a dynamic programming algorithm to obtain the initial shortest path between the enquiry point and the target point; and supplementing the initial shortest path to obtain the complete shortest path between the enquiry point and the target point. According to the method, the road network is divided into the plurality of sub-networks so as to generate the road network with the tree structure, and the shortest distance between the boundary nodes of the sub-networks at the same layer is calculated, so that the shortest path between the enquiry point and the target point can be rapidly obtained when the enquiry point and the target point are input; the method and the device not only are high in efficiency, but also well meet the requirement of real-time property.

A system and method runs a multiple spanning tree protocol (MSTP) in a computer network having a very large number of bridge domains. The computer network includes a plurality of intermediate network devices, each having a plurality of ports for forwarding network messages. Within each device, a plurality of bridge domains are defined, each bridge domain is identified by a Virtual Local Area Network (VLAN) Identifier (VID), and one or more device ports. For each port, a separate mapping of VIDs to Multiple Spanning Tree Instances (MSTIs), based on the bridge domains defined at the port, is established. Each mapping is converted to a port-based configuration digest, which is entered into Spanning Tree Protocol (STP) control messages sent from the respective port. Ports receiving STP control messages whose configuration digest values that match the configuration digests values computed for the ports are said to be in the same Multiple Spanning Tree region. Ports whose configuration digests differ from the configuration digests of received STP control messages are said to be in different regions.

A method of determining a network topology based on Spanning-tree-Algorithm-designated ports is disclosed. A first Spanning-tree-Algorithm-designated port that is associated with a network interface of a first network device is determined. A second Spanning-tree-Algorithm-designated port that is associated with a network interface of a second network device is determined. Based on the first designated port and the second designated port, it is determined whether the network interface of the first network device is connected to the network interface of the second network device.

In a packet-based switch, a method for managing data flow between the switch and other switches that are interconnected in a mesh network. The method includes receiving at the switch a topology inform packet sent from a first switch of the other switches. The topology inform packet includes at least an identifier of the first switch. The method also includes updating a link state database associated with the first switch. The link state database is configured for storing topology data pertaining to the mesh network. The method further includes forwarding the topology inform packet to at least another switch of the other switches to enable at least another switch to update a link state database associated with at least another switch.

A system and method provide for reducing a number of topology instances in a network portion implementing a multiple instance topology. Various embodiments further provide for determining if one or more of the topology instances are merge-able or conditionally merge-able to form a lesser number of representative topology instances, and if so, for causing merging of the topology instances.

The invention discloses a tree structure-based data aggregation method with reliability assurance. The aggregation method comprises the following steps: generating a tree creating module, an in-tree data aggregation module and a data detection module, and generating a tree revising module. The aggregation method adopts the tree structure to realize fast aggregation of data in the network, ensure that data can be conveniently found and used in the entire network, reduce the communications of the network in the data aggregation process and prolong the service life of the entire network; and the data detection method and the method of generating tree revise are both adopted and the phenomenons such as the damage and death of node can be monitored and found, thus increasing the accuracy and effectiveness of data transmission in the network and the reliability of the entire network.

A network is partitioned into a set of independent partitions, and the topology of each partition is determined, then merged to form a topology of the entire network. Preferably, the partitioning is hierarchical, wherein the network is partitioned to form individual VLAN partitions, and each of the VLAN partitions is further partitioned based on the nodes that are simply connected to each port of one or more selected root switches within the VLAN partition. Simple connections to each port are efficiently determined based on an aggregate address forwarding table associated with each node. Ancillary information, such as spanning tree or CDP data, may be used to facilitate efficient partitioning and/or to validate inferences that are made with incomplete information.