216 results about "Automatic protection switching" patented technology

In a packet-switched network having a plurality of nodes interconnected by links, pre-defined protection paths provide protection of a selected plurality of links. Adjacent nodes connected by a protected link are adapted to detect a failure of the protected link, to encapsulate packets within tunnel packets, to differentiate between tunnel packets and non-tunnel packets and to exchange the tunnel packets via a protection path rather than via the failed link. This results in faster automatic protection switching of packet-based traffic. The invention is particularly suited to an Internet Protocol network.

A working router is coupled to a SONET add-drop multiplexor (ADM) through a working line and a protection router is coupled to the ADM through a protection line. The routers are coupled to each other by a separate side-band connection and comprise a virtual router from the perspective of the neighboring router, which communicates with the virtual router over the SONET network using the Point-to-Point Protocol (PPP). The protection router transmits a heartbeat message to the working router over the side-band connection. If the protection router does not receive a response thereto, it initiates a line switch within the add-drop multiplexor. Once the line switch is complete, the protection router exchanges datagrams with the neighboring router, via the ADM and SONET ring to which the ADM is coupled. The protection router establishes a PPP connection between itself and the neighboring router device coupled to the SONET ring, utilizing the Link Control Protocol (LCP). The protection router includes a predetermined identifier value that identifies the originator of the request, in the LCP Identifier field of LCP request datagrams. The neighboring router includes the Identifier value received in a request datagram in the corresponding response datagram transmitted over the SONET ring to the ADM. Because datagrams received by the ADM from the SONET link are transmitted over both the working and the protect lines, the working router receives the same response as the protection router. Thus, by examining the identifier field, and recognizing the identifier value as that assigned to the protection router, the working router determines that the line switch to the protection router has occurred.

The invention is directed to providing pseudowire tunnel redundancy for VPLS and VLL services in the form of automatic protection switching of the service from a primary pseudowire tunnel to a backup pseudowire tunnel upon detection of a failure affecting the primary pseudowire tunnel. Embodiments of the invention monitor event notifications reported by a network management entity for an indication of a failure affecting the primary pseudowire tunnel; and responsive to detecting the indication, switch a service carried by the primary pseudowire tunnel to the backup pseudowire tunnel. Such event notifications include those corresponding to any of provider edge routers, interface ports, service access points, spokes, and tunnel endpoints that are related to operation of the primary pseudowire tunnel

In a router, externally received messages addressed to an active line card are bridged to a protection line card. Each line card in the router is programmed to respond to such externally received messages by directing them to the protection line card associated with the active line card as well as to the active line card. The protection line card is configured with inbound and outbound path tables that are the clones of the inbound and outbound path tables of its corresponding active line card. Bridging is accomplished by revising descriptors stored in a plurality of line cards to indicate an association between an active one of the line cards and its protection line card. Received messages are addressed using the revised descriptors to the active line card and also to its protection line card. Upon failure of an active line card, its physical interface can be disabled once its protection line card has clones of the inbound and outbound path tables and bridging has been set up.

Embodiments of the present invention provide an automatic protection switching method, device and system. The method includes: determining a part of services as to-be-switched service(s) according to change of bandwidth when monitoring that the bandwidth of the first transmission path changes; and switching the to-be-switched service(s) between links on the second transmission path and the first transmission path. Another method includes: receiving a partial switching message from a peer network edge node through the first transmission path or the second transmission path; and determining the to-be-switched service(s) according to indication information about the to-be-switched service(s) or bandwidth change information in the partial switching message, and switching the to-be-switched service(s) between links on the first transmission path and the second transmission path.

A computer network has a plurality of routers that deliver data packets to the network via a plurality of links. At least one router provides automatic protection switching in the event of a link failure. The at least one router includes a plurality of data interfaces for streams of data packets to enter and exit the at least one router; and a backup controller. The backup controller includes a backup path manager, a link monitor, and a backup packet processor. For at least one link of the routing node, the backup path manager identifies a backup routing path for forwarding affected data packets in the event of a failure of the at least one link. The link monitor monitors the plurality of links to determine when a link fails. When a link which has a backup routing path fails, the backup packet processor attaches backup routing path instructions to affected data packets routed over the failed link, and forwards the affected data packets via the backup routing path.

An apparatus and technique configures an intermediate network node, such as an aggregation router, to implement automatic protection switching (APS) redundancy among its line cards in the event of a failure to one of those cards. The APS line card redundancy provides redundancy among a pair of line cards connected to a performance routing engine of the router. Internal APS data paths are implemented in the router through the provision of an alias logic circuit that selects packet data from one of an adjacent pair of line cards and sends identical copies of data to that adjacent pair of line cards.

An existing protection mechanism is enhanced through the use of an automatic protection switching protocol data unit (APS PDU). In conjunction with transmitting Ethernet frames to a second bridge over a primary path, a first bridge transmits APS PDUs to the second bridge over a secondary path. The APS PDUs provide the second bridge with information about the protection switching mechanism being used and provide indications regarding the status of the primary path. In particular, protection switching may be facilitated by forming an APS PDU that is extended to include an indication of an identity for a trunk or a primary path before transmitting the APS PDU to the second bridge. Alternatively, after forming a regular APS PDU, protection switching may be facilitated by encapsulating the regular APS PDU with information identifying a trunk or a primary path before transmitting the APS PDU to the second bridge.

A method of controlling traffic forwarding in a Provider Backbone-Traffic Engineered (PBB-TE) network. A protection group (PG) is defined, and including N working Traffic Engineered Service Instances (TESIs) and M protection TESIs. An Automatic Protection Switching Protocol Data Unit (APS PDU) is defined, which includes information defining at least a state of the protection group. This APS PDU is forwarded only through the protection TESI(s).

A computer network has a plurality of routers that deliver data packets to the network via a plurality of links. At least one router provides automatic protection switching in the event of a link failure. The at least one router includes a plurality of data interfaces for streams of data packets to enter and exit the at least one router; and a backup controller. The backup controller includes a backup path manager, a link monitor, and a backup packet processor. For at least one link of the routing node, the backup path manager identifies a backup routing path for forwarding affected data packets in the event of a failure of the at least one link. The link monitor monitors the plurality of links to determine when a link fails. When a link which has a backup routing path fails, the backup packet processor attaches backup routing path instructions to affected data packets routed over the failed link, and forwards the affected data packets via the backup routing path.

An Ethernet PHY hardware device supports Ethernet MAC SDH / SONET Automatic Protection Switching (APS) functionality for managing protection from failures and recovery from failures on an Ethernet network. An Ethernet PHY sublayer stored on the Ethernet PHY hardware device is configured to monitor working and protect channels and generate an interrupt upon detection of a hard failure or a soft failure. Upon detection of port failures or link failures, the Ethernet PHY sublayer generates the interrupt to invoke an Ethernet MAC Client APS Controller configured to generate and terminate APS requests on working and protect channels to manage protection of working and protect channels from failures and recovery from failures on the Ethernet network. The Ethernet PHY hardware device is configurable for use with a plurality of different network topologies to manage protection from hard or soft failures and recovery from hard or soft failures on the Ethernet network using the Ethernet PHY sublayer.

An apparatus and method for a communications network including at least one interface circuit reads frame data received from the communications network and writes frame data to be transmitted over the communications network, the frame data including a plurality of transport overhead fields. The apparatus includes signature logic coupled to the interface circuit, the signature logic identifying signature data and writing the signature data into transport overhead fields in an outgoing frame. Reflector logic coupled to the interface circuit copies data from one of the received transport overhead fields, the copied data being placed into a transport overhead field in the outgoing frame, the copied data including the received signature data. The interface circuit compares the copied data to earlier received frame data from the communications network, the determination of a mismatch identifying a transition requiring an update of at least one routing table. The data is used to determine configuration compatibility between interfaces and among a plurality of tributary interfaces and to eliminate dependence on multiplexers that transmit to routers with protect circuits according to protection switching protocols. A method for a communications network includes transmitting signature data in a transport overhead field, the data identifying one of interfaces in the local routers, returning the data to the local router, and configuring a communications relationship using the data. The method includes using the data to determine which is an active interface and to determine whether to update at least one routing table and using the data to configure the interface circuits.

A SONET / SDH architecture is disclosed that enables the multiplexing of STS-1's from different SONET / SDH rings into a single STS-N for transmission via a single optical fiber, but while maintaining the association of each of the STS-1's with its respective SONET / SDH ring. For example, when an STS-48 carries 12 STS-1's from a first SONET / SDH ring and 12 STS-1's from a second SONET / SDH ring, the STS-48 carries: the automatic protection switching channel for the 12 STS-1's from the first SONET / SDH ring (with addresses specified in the address space of the first SONET / SDH ring); and the automatic protection switching channel for the 12 STS-1's from the second SONET / SDH ring (with addresses specified in the address space of the second SONET / SDH ring).

A method and system for protection switching in Ethernet rings are disclosed. The method for protection switching in Ethernet rings includes: receiving a server signal fail (SSF), an Ethernet lower layer fault signal, a remote defect indication (RDI) for informing a different port about a fault state when a uni-directional fault is generated, and ring-automatic protection switching (R-APS) information for requesting Ethernet ring protection switching; comparing the SSF, the RDI, and the R-APS information, and setting states of the first and second Ethernet rings; determining a protection switching priority level of each of the first and second Ethernet rings according to the states of the first and second Ethernet rings; and performing protection switching on the first and second Ethernet rings according to their protection switching priority levels.

A system and method for providing APS (automatic protection switching) redundant pair control protocol signaling for multi-nodal APS (MN-APS) is provided. Periodic liveliness messages are exchanged between each node of a redundant pair. Each liveliness message contains an IHY (I heard you) message which indicates whether or not the sender of the liveliness message received within a duration of a hold time a previously transmitted liveliness message from the recipient. When more than one MN-APS group is configured between two redundant nodes, liveliness messages are bundled together to reduce processing loads.

Methods, systems, and computer program products for implementing automatic protection switching for media packets, such as ATM cells or IP packets that carry media content, in a device that includes an Ethernet switching fabric are disclosed. According to one method, first and second packet network interfaces of the device are configured to function as working and protection APS interfaces. At least one of a media processing resource and an Ethernet switch fabric of the device are configured to replicate egress media packets from the media processing resource to the working and protection APS interfaces. Egress media packets from the media processing resource are forwarded to the working and protection APS interfaces via the switch fabric. Ingress media packets received at the working APS interface are forwarded to the media processing resource via the Ethernet switch fabric. Media packets received at the protection APS interface are discarded.

The present disclosure provides Optical Transport Network (OTN) port protection systems and methods using flexible switch criteria. Specifically, the OTN port protection systems and methods provide linear protection in OTN such as 1+1 Protection with Automatic Protection Switching (APS) and / or 1+1 Subnetwork Connection Protection (SNCP) Protection. The OTN Port Protection with flexible switch criteria allows a user to provision a protection application on an OTN Port and select a switch criteria, Section Monitoring, Path Monitoring, or Tandem Connection Monitoring, without considering the provisioning state of an Optical channel Data Unit level k (ODUk) entity. The ODUk entity may either be cross-connected in the LO case or terminated in the HO case. The ODUk entity may be provisioned independently, after the port protection has been established.

To perform protection switching between tunnels in a network, Y.1731-based APS messages are often sent from a management system to nodes at the tunnels' end-points. If the management system is located near one node (local node) and far away from the other node (remote node), the APS message, which operates at the Ethernet service layer, travels to the remote node slower than traffic over the tunnels. This slower transmission time may prevent the remote node from performing a switch within a desired timeframe. The disclosed embodiments include a 1:1 bidirectional VLAN-based protection arrangement that accomplishes a 50 millisecond switching time without using Y.1731-based APS messages. The embodiments accomplish this by sending a switching command from the management system to the local node and modifying a message already traveling from the local node to the remote node to include a switching message that causes the remote node to perform the switch.

A line card in a network node having a local memory coupled to a local controller and local logic circuit. The local memory in the line card stores state information for signals processed by the line card itself, as well as state information for signals processed by other line cards. The logic circuit and controller implement a same fault detection and signal processing algorithms as all other line cards in the group, to essentially effectuate a distributed and local hardware based control of automatic protection switching (APS) without interrupting a central processor. The line card also performs error checking and supervisory functions to ensure consistency of state among the line cards.

A method, a network, and a node each implement the transmission of Automatic Protection Switching (APS) switching coordination bytes across an OTN network. A working signal and a protection signal are received, one of which is designated as an active signal. The active signal is encapsulated in an Optical channel Data Unit (ODU) signal. APS switching coordination bytes from the working and protection signals are placed in an overhead segment of the ODU signal. The ODU signal is transmitted into and received from an Optical Transport Network (OTN) network. The working and protection signals are recreated based on the active signal encapsulated in the ODU signal and the APS switching coordination bytes in the overhead segment. The recreated working and protection signals are transmitted. In this manner, a single ODU signal may be used to transmit both the working and protection signals.

The invention discloses a protection switching method and system and an optical network node. The protection switching method comprises the steps of: when receiving detection information including at least one trigger condition, determining protection groups influenced by the trigger condition from a plurality of pre-configured protection groups, respectively carrying out automatic protection switching (APS) protocol operation on the determined protection groups to obtain operation results corresponding to the protection groups, and uniformly executing protection switching operation on the determined protection groups according to the operation results. In the scheme provided by the invention, because the APS protocol operation is carried out on the determined protection groups influenced by the trigger condition centrally, the protection switching operation is uniformly executed on the determined protection group, and a once protection switching mechanism is triggered by only calling a once APS protocol processing program, therefore, compared with the mode of serially executing the protection operation on the protection groups, the protection switching method has the advantage of greatly saving total time consumption of protection switching.

A method for cell replication in which a request for data transmission and mapping information are received by a crossbar and a scheduler and are sent by one of a plurality of software configurable slot remap registers. The mapping information is indicative of a destination slot and a backup destination slot to which the data is to be transmitted. The method replicates the data by transmitting the data to the destination slot and to the backup destination slot when the data arrives at an input slot of the crossbar.

The invention relates to a method for realizing multi-protocol label switching bidirectional protection switching. The method mainly includes: first, in an MPLS (multiprotocol label switching) network, configure corresponding bidirectional protection switching policy information for a bidirectional LSP (label switching path) based on an APS (automatic protection switching) protocol; then, when in the MPLS network based on When the APS protocol determines that bidirectional protection switching is required, the bidirectional protection switching operation is performed according to the configured bidirectional protection switching policy information. Therefore, the present invention can realize effective protection to MPLS LSP two-way data channel, guarantees that the time delay of two-way flow is in equal; Simultaneously, the APS agreement that the present invention introduces can cover the protection of MPLS LSP one-way data channel, thereby unified one-way and The realization of the mechanism of two-way protection.

An Ethernet Automatic Protection Switching (APS) Bridge Selector is provided for supporting SDH / SONET APS standard functionality in Ethernet Networks. In accordance with one embodiment, an Ethernet APS Bridge Selector is provided for bridge, selector, and switchover functionality for a plurality of Physical Layer (PHY) hardware devices. The Ethernet APS Bridge Selector provides support for any Media Access Control (MAC) hardware to PHY interface / interconnect. The Ethernet APS Bridge Selector can be managed via interfaces, signals and / or control / register interfaces.

Each span of a communication network, such as a BLSR ring, is assigned a unique span ID. When a node of the network detects a failure in a span (including a straddling span) of the network, the node exchanges commands, according to an automatic protection switching (APS) protocol, that request other nodes of the network to switch network traffic from a working span (including a straddling span) to a protect span. The commands specify the working span by its span ID, without necessarily specifying a source node ID or a destination node ID for the commands. The span ID occupies fewer bits in the commands than a combination of the source node ID and the destination node ID. Consequently, the messages can accommodate span IDs larger than four bits, and networks can have more than 16 nodes. Alternatively, the commands specify a destination node ID without a span ID or a source node ID, or the commands specify a source node ID without a span ID or a destination node ID. Alternatively, a straddling span is identified by node IDs of its two nonadjacent terminal nodes. A set of rules governs straddling span switching. Optionally or in addition, more than four bits are available for bridge requests command codes in the messages. Thus, more than 16 unique bridge requests commands can be defined.

The invention discloses a flexible ethernet 1:1 protection switching implementation method, and relates to the technical field of flexible ethernet networking protection. A work path and a protection path are arranged between two end nodes; the two end nodes are set to use the work path to transmit services by default, the protection path transmits services different from the services in the work path when the services are not switched to the protection path, and the two end nodes use the work path to receive the services by default; when the end nodes detect port fault alarm or AIS alarm on the work path, the services are switched to the protection path; and when cancellation of port fault alarm and / or AIS alarm on the work path is detected: the services are maintained to be received from the protection path or the work path is switched on to receive the services after water-to-restore time. Meanwhile, the end nodes transmit an APS command to the opposite end node, and the opposite end node performs the synchronous protection switching action according to the APS command so that rapid automatic protection switching in the flexible ethernet can be implemented.

The embodiment of the invention provides an Ethernet-ring-network automatic protection switching method and a device thereof. The method mainly comprises: after nodes detecting that links between nodes go wrong or recover from failure, nodes determine Ethernet-ring instances which are affected or not affected by the failure or recover from the failure; protection switching messages carrying information of Ethernet-ring instances which are affected or not affected by the failure or recover from the failure are sent. The utilization of the embodiment of the invention can realize automatic protection switching of Ethernet-ring-network under a circumstance of reducing OAM (Operation, Administration and Maintenance) layers and reducing resources of VLAN (Virtual Local Area Network).

The invention discloses an automatic protection switching method and device, which are applied to routing equipment configured with the automatic protection switching APS. The method comprises the steps of arranging an aggregation port on the routing equipment, adding a port of an APS-related link on the routing equipment to the aggregation port as a member port, setting the current working link port in the aggregation port as an available port, setting a corresponding protection link port as an unavailable port, and arranging an identifier of the aggregation port in a forwarding table entry as an outlet port identifier; and after an APS event is triggered by the routing equipment, obtaining the aggregation port of the current working link port, setting the current working link port in the aggregation port as an unavailable port, and setting a protection link port corresponding to the current working link port as an available ort. By using the invention, the switching efficiency and speed of the forwarding table entry in the APS switching process can be improved.