136 results about "Open Shortest Path First" patented technology

Wide-area data communications utilize regional networks transporting IP-over-Ethernet on fiber. For certain Layer 2 services, a regional implementation of the network makes limited use of spanning tree protocol on a backbone ring. Learning bridge operations in switches on associated access rings involve a short default for an aging timer. For use of Open Shortest Path First (OSPF), the connection of each access ring to the backbone ring uses a pair of routers with dual links therebetween. One of these links is bonded to the backbone (OSPF Area 0), whereas the other link is bonded to the Area of the respective access ring. Also, certain routers within each regional network form a mini-autonomous system, for boundary gateway protocol (BGP). The mini-autonomous systems of the regional networks form a confederation. The network utilizes route reflectors in the mini-autonomous systems. The Internet carries confederation commands to and from a designated hub.

An agile digital communications network has a number of routers that serve as nodes in a mesh network communicating between a user device (e.g., computer, server, etc.) and a target device (e.g., disc storage cabinets, tape, jukebox, etc.). The routers operate on an open shortest path first protocol, each router having two or more interfaces or links to other routers. When a link connected to a router is down and is in the shortest path to another router identified in a communication packet, the packet is forwarded to the identified router on a precalculated alternate route that does not use the unavailable link. IP tunneling assures that routing loops do not occur and send the packet back to the router with the unavailable link because it would have been in the shortest path of an intermediate router. A tunneling technique is provided that maximizes the levels of encapsulation needed at two, regardless of the size or configuration of the network. An unavailable link is not broadcast immediately throughout the network, giving the link an opportunity to be restored before all of the routers are called on to recalculate the shortest paths and alternate paths. During a short interval following the discovery of an unavailable link, then, a router connected to that link is in a state identified as the Use Alternate Path state, and the link is repeatedly checked for availability. Each router calculates and stores the alternative paths to each other router after first calculating the shortest path to each other router. The alternate paths are pulled up and used when an unavailable link is detected. Dijkstra's algorithm is used to calculate the shortest paths. A new algorithm called the iterative dynamic Dijkstra's algorithm is used to calculate the alternative routes.

In highly-available Open Shortest Path First (OSPF) routing in a network, the dynamic state of a backup OSPF instance in a router is synchronized with the dynamic state of an active OSPF instance using explicit message transmission from the active instance to the backup instance. After this, the dynamic state synchronization of the backup OSPF instance is maintained using a combination of explicit message updates from the active OSPF instance together with a message flow-through mechanism. In the event of fail-over of the active OSPF instance, then the router recovers seamlessly without reconfiguring or interrupting traffic among peer routers in the network, by functionally substituting the synchronized backup OSPF instance for the active OSPF instance, such that the backup OSPF instance establishes itself as the new active OSPF instance.

The invention provides a method and system for a network which includes a plurality of nodes, preferably routers, a shared network segment for communication between the nodes, and several multicast channels in the shared network segment on which the nodes, preferably routers, can send multicast messages to the other nodes. A specific multicast channel is provided on which the nodes can send specific start multicast messages to other nodes, wherein a node which starts a protocol application, preferably a routing protocol application such as Open Shortest Path First (OSPF) protocol, is adapted to send a multicast start message on the specific multicast channel. Another node, preferably a router, receiving this start message is adapted to validate the authenticity of the start message and to send a response message.

Multi-chassis fabric-backplane enterprise servers include a plurality of chassis managed collectively to form one or more provisioned servers. A central client coordinates gathering of provisioning and management information from the chassis, and arranges for distribution of control information to the chassis. One of the chassis may perform as a host or proxy with respect to information and control communication between the client and the chassis. Server provisioning and management information and commands move throughout the chassis via an Open Shortest Path First (OSPF) protocol. Alternatively, the client may establish individual communication with a subset of the chassis, and directly communicate with chassis in the subset. Server provisioning and management information includes events generated when module status changes, such as when a module is inserted and becomes available, and when a module fails and is no longer available. Each chassis includes a switch fabric enabling communication between chassis modules.

Systems and method for selecting open shortest path first (OSPF) aggregates and aggregate weights for a particular area. In one embodiment, an aggregate selecting system includes: (1) a database for containing data pertaining to candidate OSPF aggregates and corresponding weights and (2) an aggregate selector, associated with the database, that selects at least a subset of the OSPF aggregates such that the shortest path length between the particular source and destination subnets resulting from advertisement of a set of weighted aggregates approaches the shortest path length between the particular source and destination subnets irrespective of the advertisement. In one embodiment, a weight selection system includes: (1) a database for containing data pertaining to candidate OSPF aggregates and (2) a weight assigner, associated with the database, that assigns, for the OSPF aggregates, weights based on either an average distance of subnets in the area for a particular area border router (ABR) of the area or a search heuristic.

A method and apparatus for processing link down events associated with links between adjacent nodes is described. A node receives link down events associated with a link fault protocol for a link between the node and a neighboring node. In response to receiving the link down event, the node removes a data structure associated with the neighboring node from a forwarding table associated with a routing protocol running on the node. The node reserves the data structure for speedy adjacency recovery. In addition, the node places the neighboring node in the initialize state of the routing protocol.

The invention discloses a data packet sending method and device, and a network architecture. The method is applied to a data network switch in the network architecture. The method comprises the following steps of receiving a first packaging packet of a target data packet sent by a first computing node, an open shortest path priority routing protocol and an equivalent multi-path routing protocol which are configured in the data network switch, and an open shortest path priority routing protocol configured in the network node, and determining a first network node from the network node; sending the first network node to the first packaging packet, so that the first network node sends the target data packet to the destination host. By adopting the provided scheme, the data flow forwarded by the same group of virtual routers serving virtual machines on the same network segment can realize the distributed flow forwarding in all the virtual routers in the group, so that the performance bottleneck problem of a single virtual router in the prior art during the data packet forwarding is solved.

The invention provides a method and system for a network which includes a plurality of nodes, preferably routers, a shared network segment for communication between the nodes, and several multicast channels in the shared network segment on which the nodes, preferably routers, can send multicast messages to the other nodes. A specific multicast channel is provided on which the nodes can send specific start multicast messages to other nodes, wherein a node which starts a protocol application, preferably a routing protocol application such as Open Shortest Path First (OSPF) protocol, is adapted to send a multicast start message on the specific multicast channel. Another node, preferably a router, receiving this start message is adapted to validate the authenticity of the start message and to send a response message.

A method and apparatus provides protection against resource failures in Open Shortest Path First (OSPF) networks, without increasing the complexity of the network topology and / or management. An internal router (IR) automatically maintains a back-up link in a dormant state until a network failure affecting communications with a primary adjacent area border router (ABR) is detected. Upon detection of the network failure, the IR activates the back-up link in order to enable traffic flow to an alternate adjacent ABR, which by-passes the network failure. Upon recovery of communications with the primary adjacent ABR, the IR automatically deactivates the back-up link and resumes traffic flow through the primary adjacent ABR. As a result, traffic is forwarded into the back-up link only when communications with the primary adjacent ABR has failed, thereby maintaining simplicity in the network topology, and minimizing network management and administration requirements.

The invention discloses a method and a device for acquiring the shortest routing path between two nodes in a network. The device comprises a routing information acquisition probe which is used to acquire the flooding link status announcing message of each open shortest path priority protocol area at real time, a memory which is used to memorize link status data bases maintained by the routing information acquisition probe for all the open shortest path priority protocol areas, a processor which is used to calculate the shortest routing path between two nodes in the network input by a user according to the link status data bases, and an output unit which is used to output the calculation result of the processor. The method includes the steps of acquiring the routing information and constructing a shortest routing path priority search tree. The method and the device have the advantages that the user can conveniently acquire the shortest routing path between two nodes in the network, which is easy to realize and saves time. The method and the device can be used to monitor a specific routing path, to locate a routing abnormal fault and to guarantee the safety of the specific routing path.

The invention discloses a system and a method for realizing OLT (Optical Line Terminal) voice double upper-link protection based on OSPF (Open Shortest Path First Interior Gateway Protocol) routing protocol, and relates to the field of PON (Passive Optical Network). A CPU of an OLT master control panel in the system comprises an OSPF module and an RTM (Running Timer Meter) module. Two upper-link ports of an OLT are respectively connected with a NGN (Next Generation Network) through three-layer exchangers A and B to connect with a remote-end MGC (Media Gateway Controller) server; paths A and B are formed between the OLT and the MGC server; the OLT and the three-layer exchangers A and B are respectively configured with the OSPF protocols and operate; the OLT learns the routes of all network sections on the paths A and B through the OSPF route protocol; the OSPF module stores the learnt routes in the route table of the OSPF module and announces the learnt routes to the RTM module; and the RTM modules collects the route items and writes the route items in an RIB table. When a main link breaks, the OSPF route protocol learns the route of a backup link and carries out rapid protective rearrangement to the high real-time voice business among internetworking nodes.

A method and apparatus resynchronizes a link state database (LSDB) of a non-stop forwarding (NSF) router with the LSDB of a neighboring router (“neighbor”) while maintaining an existing adjacency with the neighbor in a computer network. An out-of-band resynchronization process executes on the routers to essentially maintain the existing adjacency between the router and neighbor, rather than resetting that adjacency as defined by a conventional resynchronization approach. By keeping the adjacency “up” from the perspective of a routing protocol, such as the Open Shortest Path First routing protocol, the adjacency can be used for continued data traffic to and from the NSF router.

The invention relates to the field of communication technology and discloses a method and a system achieving network redundancy and data flow seamless switching. The method includes the following steps of using a virtual router redundancy protocol (VTRP) to trigger switching of a first transmitting device to a second switching device according to the changes of links, and using an open shortest path first (OSPF) interior gateway protocol to update route information and to switch the flow direction of the data flow. Main and standby switching is achieved through the use of the VRRP, and when the main and standby states of a VRRP group switch, and the OSPF interior gateway protocol is used for updating the route information and switching the flow direction of the data flow, so that after a linkage mechanism of the VRRP and the OSPF interior gateway protocol is used for achieving the switch, the route information is timely updated, the problem that the data flow direction is wrong and therefore the use of a user is affected is avoided, and the data flow seamless switching is ensured.

A network processor is used for the routing of objects in non-data networking applications. The processor utilizes the Open Shortest Path First (OSPF) algorithm to capitalize on the benefits of data control for object traffic control and costs. A network processor is used at each point in a grid represented by intersecting paths. One or more routing tables are embedded in each network processor. Each routing table describes links with other network processors in the grid to which the network processor is interconnected. A cost factor is associated with each link and is constantly updated by the OSPF as new information becomes available. If a link or route becomes unavailable, the cost is set at infinity. The system then creates an alternative path for the object between a source and the desired destination that bypasses the unavailable link or route.

A system (800) improves a network designer's ability to analyze a data network having several routers. The system (800) accesses static routing information and / or open shortest path first route summarization information, determines an identity of a network prefix using the accessed information, and analyzes the data network using the determined identity. The network designer can use this determined identity for traffic analysis or modeling of the data network.

The invention discloses a trust management system based trusted reconstructing method of an Open Shortest Path First (OSPF) routing protocol, which comprises the following steps of: (1) before each router is added into a network, registering to the trust management system, and sending corresponding trust certificates to the routers by the trust management system, the trust certificates including comprehensive trust values of the routers and each being calculated according to safe parameters and configuration parameters of the routers and all the subjective trust value of the neighbor router to the routers by the trust management system; (2) transferring the trust certificates among the routers through hello information, wherein an adjacency relation is not established for the router without the trust certificate, all the routers in the network are ensured to have own trust certificates; (3) each router calculating the subjective trust value of the neighbor router based on network real time parameters including link flow, packet loss probability, retardation, transmission rate of the packet and reliability of the packet, during an interactive work with the neighbor router, calculating a total trust value of the neighbor router by using the comprehensive trust value and the subjective trust value of the neighbor router, and modifying a metric field of a link-state announcement Router_LSA packet as the total trust value and synchronizing a link-state data base;(4) modifying a Dijkstra algorithm, using a reciprocal of the total trust value between the routers as the parameter for the arithmetic computation, selecting the router with higher trust value to generate a shortest path tree, and forming a trust routing list; (5) periodically reporting the subjective trust value of the neighbor routers to the trust management system by each router, simultaneously obtaining the parameter required for computing the subjective trust value, updating the trust certificate of each router at fixed time, and eliminating the router with the overdue trust certificate out of the network to maintain the topological structure of the whole network.

The routing calculation method based on the shortest opened route priority routing protocol includes organizing with Hash list class-V LSA link state library, which has its Hash units and LSAs with routing calculating mark; adding newly accepted LSA into corresponding Hash unit and setting separately the said unit and the LSA routing calculating mark the same as the LSA destination address in this unit; then calculating the routing of LSA set by the routing calculating mark; and finally updating the routing list based on the calculation result. Adopting partial routing calculation method, the present invention can decrease the processor occupying time and raise the outing calculating efficiency. To the network nodes operating OSPF protocol, the said method can avoid instantaneous service break, instantaneous no response of router and other equipment, etc.

The invention discloses a routing method adapting to make-and-break connection data transmission of a spatial network link. By using the routing method disclosed by the invention, the convergence rate can be significantly improved, and the overhead of a routing protocol can be significantly reduced. The routing method is implemented through the following technical scheme: each routing node receives routing node three-dimensional location information through a measurement and control link, a predicted link state matrix is acquired, link state information and a predicted routing table of the routing node at each link variation moment are calculated, and the calculated link state information is stored into a link state information database; a sub-group to be sent acquires a link variation moment and a break-make condition through the predicted routing table, a routing node to-be-sent sub-group stores the link state information into a link state information database through switching each routing node variation and variation moment, and the link state information is written into a predicted route calculation matrix; when an OSPF (Open Shortest Path First) reaches a full state, each routing node calculates an actual routing table again according to the updated link state information database so as to replace the predicted routing table.

The invention discloses an interconnection mechanism between a software defined network (SDN) subnet and an IP subnet in an autonomous system, wherein a whole network is divided into three basic areas of a backbone area Area 0 and a subnet area Area 1 which are composed of traditional network equipment; and a SDN subnet area which is composed of a converter, an OpenFlow switch and a controller. The subnet area Area 1 is connected with the Area 0 through an area border router, and the SDN subnet area is connected with the Area 0 through a converter. A whole system operation process comprises making forwarding roles in the SDN network and the IP network, transmitting IP network connection information to the SDN network, and transmitting SDN network connection information to the IP network. The interconnection mechanism realizes interconnection between the SDN network and a traditional network by means of an open shortest path first (OSPF) protocol, and furthermore has advantages of easy disposition, easy use, high extendibility, high automation degree, etc.

Methods, systems and computer program products for integrating data in a communications network received at provider (P) routers from provider edge (PE) routers having a plurality of different configurations are provided. Global collection and export parameters for the P routers are configured. A collector associated with the P routers is configured to maintain a netflow exported data table for the P routers based on the global collection and export parameters received from the P routers. P router text files are configured. The P router text files identify all P routers associated with the collector using Internet protocol (IP) addresses associated with each of the P routers. A destination PE router is located for a selected P router based on IP addresses in the P router text file associated with the selected P router such that the interface IP address of the selected P router is matched with the open shortest path first (OSPF) router identification of the destination PE router.

A method and system for extracting and building end-to-end route information in a multi-area Internet protocol (IP) autonomous system (AS) operated according to a link state routing protocol such as the Open Shortest Path First (OSPF) protocol is disclosed. The method and system enables a user, such as a network administrator, to explicitly identify a full set of paths (links and routers) that a given IP packet would potentially traverse from its entry point in the area of the AS where it originates until its exit point in its intended destination or exit area.

A method of configuring link-scope-type managed objects in IP-based networks from a centralized management node. An IP-based network includes at least one management station, a set of network nodes, and communication links between the network nodes and between the management station and the network nodes. Preferably, an Open Shortest Path First (OSPF) topology graph of the network is prepared, and a set of target links to be configured is identified. The target links are then classified into N disjoint subsets, T1-TN. The links in each subset are then configured in parallel, starting with subset T1 and sequentially handling each subset one-by-one. The target links may be classified by removing non-target links that are not to be configured from the OSPF topology graph, building a LinkGraph to determine the dependencies between the links remaining in the OSPF topology graph, and building a LinkTree from the LinkGraph to classify the target links into the subsets based upon the dependencies between the links.

The invention discloses an OSPF (Open the Shortest Path First) protocol-based graceful restart (GR) method and a router. The method comprises the following steps of: recording neighbor information in real time, restarting the router, then, carrying out a GR process according to the recorded neighbor information, informing neighbors corresponding to the recorded neighbor information to maintain a neighbor relationship, and informing the neighbors corresponding to the recorded neighbor information to finish the GR process and enter a normal OSPF process after the LSDB (Link State Database) synchronization is finished. Based on the same method, the invention further provides the router, so that the uninterrupted flow in the GR process is guaranteed.

The invention relates to a method for testing convergence property of autonomous system network route, belonging to the technical field of network test. The invention is characterized in that the method respectively tests the convergence property to an open shortest path first (OSPF) network and an internal border gateway protocol (iBGP) network. A testing scene is firstly constructed, two router nodes in the network are selected, and a flow generator and a flow acquirer are respectively equipped on these two router nodes; and in the iBGP router convergence property testing, the flow acquirer is used as a router simulator at the same time. With the introduction of network link, node failure event or BGP simulation route oscillation, at the same time, the planar transmission performance indices of network data are measured, and convergence time of route control plane can be estimated according to the message number transmitted and received from the flow generator and flow acquirer. The inventive method has low requirements to testing equipments and is easy to implement.

The invention discloses a graceful restart method, which comprises the following steps of: recording neighbor information in advance; when the OSPF protocol needs to be restarted, recording a restarting reason, and notifying the neighbor corresponding to the neighbor information in a record to enter a help flow; and after the OSPF protocol is restarted, carrying out a GR (Graceful Restart) flow according to the recorded restarting reason and the neighbor information. The invention also provides a router which can carry out uninterrupted service upgrade under the condition that the OSPF is not prepared.

The invention discloses a network traffic distribution method and a routing method for network traffic distribution. The network traffic distribution method includes: transmitting all or part of traffic of a source node to a target node through multiple chains, with the traffic of any link to the target node being approximate to set traffic of the link. The set traffic of each link is determined according to maximum link usage and link bandwidth. The network traffic distribution method and the routing method for network traffic distribution have the advantages that distributed link traffic of the network traffic is optimally distributed, the maximum link usage of the network is decreased, and by establishing the two-dimensional routing based forwarding method to achieve optimal network traffic distribution, the problem that non-shortest paths of the existing in-domain OSPF (open shortest path first) routing method is solved and the quality of network services is improved.

The invention discloses a method for adjusting the utilization rate of a network link. The method comprises the following steps that a network architecture is obtained, and a basic network architecture of a network is obtained, wherein the basic network architecture contains the number of nodes in the network and node connecting modes; the optimal weight configuration is obtained, and the optimal weight configuration is obtained based on the open shortest path first protocol and software-defined network technology; the network is configured based on the optimal weight configuration, and therefore the expected network link utilization rate adjustment result is obtained. Compared with the prior art, by means of the method for adjusting the utilization rate of the network link, a lower and maximum network link utilization rate can be obtained, and network performance is improved.

The invention discloses a router in an OSPF (open shortest path first) network and a processing method thereof. The method applied to a TBR (transit boundary router) connecting a first management unit and a second management unit includes: receiving a new LSA (link-state advertisement), comprising original LSAs which are router LSAs or network LSAs and topological LSAs for describing topological information, of the first management unit; storing the original LSAs and the topological LSAs comprised in the new LSA into a LSDB (link-state database), and establishing associations between the original LSAs and the topological LSAs; before sending the LSAs to the second management unit, judging whether each original LSA in the LSDB is provided with the associated topological LSA or not; if yes, sending the topological LSA associated with the original LSA to the second management unit. By the use of the router and the processing method, safety of the management units is enhanced and route diffusion is reduced.