Abstract: An apparatus and method for protection switching are disclosed. The protection switching method in accordance with an example of the present disclosure is capable of smoothly processing a protection switching while preventing a data path mismatch occurring in the protection switching in a case in which a forced switching command (FS), which is a passive command, and a signal failure (SF) of a protection path occur at both end nodes, respectively, when a linear protection switching is performed by use of a protection state coordination message in a packet network or a packet transport network.

Abstract: A method for managing an Ethernet ring network of a VLAN-based bridge is provided that includes: registering a major-ring VLAN ID (VID) in a ring port filtering database of a ring protection link owner node in accordance with a request for registering the major ring VID from an Ethernet Ring Protection controller mounted on the ring protection link owner node of a major ring; delivering, by the ring protection link owner node, a VID registration message to other nodes which belong to the major ring through a ring port; receiving the VID registration message through the ring port and registering the major ring VID in a ring port filtering database of each node itself, by each node belonging to the major ring; and delivering, by each node belonging to the major ring, the VID registration message to other nodes belonging to the major ring through the ring port.

Abstract: Provided are a shared mesh protection switching apparatus and method. The shared mesh protection switching apparatus includes a plurality of linear protection switching processors allocated to the linear protection domains respectively and configured to provide a switching report signal in response to fault occurrence in the corresponding linear protection domains or a linear protection switching operation, and perform a function of limiting use of the shared section in response to a provided lock signal, and a mesh protection switching processor configured to select at least one linear protection domain to be limited in use of the network resources of the shared section according to a predetermined reference when the switching report signal is provided and provide the lock signal to a linear protection switching processor corresponding to the at least one selected linear protection domain.

Abstract: There is provided a method for managing an Ethernet ring network of a VLAN-based bridge that includes: registering a major-ring VID (VLAN ID) in a ring port filtering database of a ring protection link owner node in accordance with a request for registering the major ring VID (VLAN ID) from an ERP (Ethernet Ring Protection) controller mounted on the ring protection link owner node of a major ring; delivering, by the ring protection link owner node, a VID registration message to other nodes which belong to the major ring through a ring port; receiving the VID registration message through the ring port and registering the major ring VID in a ring port filtering database of each node itself, by each node which belongs to the major ring; and delivering, by each node which belongs to the major ring, the VID registration message to other nodes which belong to the major ring through the ring port.

Abstract: An apparatus of determining blocking in an Ethernet ring network sets blocking with respect to each of the plurality of links in an Ethernet ring network, and determines one of the plurality of links as a link to be blocked by using traffic request amounts of a plurality of service flows with respect to the respective links set to be blocked.

Abstract: A method for updating a filtering database in a multi-ring network, includes: when the topology of a lower ring in a multi-ring network, in which a plurality of ring networks are connected by two ring connection nodes, is altered and the ring connection node detects the alteration in the topology of the lower ring, erasing, by the ring connection node, its filtering database; generating, by the ring connection node, a control message including a ring ID, a blockage flag, and an erasure flag; transmitting the control message in both directions of the ring; and determining, by a node which receives the control message, to erase a filtering database by referring to and correcting the blockage and erasure flag information included in the control message.

Abstract: A method for protection switching in a shared node where protection resources of a plurality of end-to-end linear protection domain are shared is provided. The shared node receives a first protection switching event message notifying that a protection switching event occurs from a first node of a first end-to-end linear protection domain, and determines whether to prohibit protection switching on a second end-to-end linear protection domain by comparing a priority of the first end-to-end linear protection domain with a priority of the second end-to-end linear protection domain.

Abstract: There is provided a protection switching apparatus including: a path management unit to establish a plurality of connection paths for transmitting/receiving packets, and a plurality of protection paths that are able to substitute for the plurality of connection paths, respectively, and to create a protection group including the connection paths and the protection paths; a protection group controller to determine whether failure has occurred on the connection paths, based on path state information for each path included in the protection group, the path state information stored in the protection group table storage, and to issue an instruction for protection switching, according to the result of the determination; and a protection switching unit to perform protection switching of a path in which failure has occurred to a protection path corresponding to the path in which failure has occurred, according to the instruction for protection switching.

Abstract: Provided are a shared mesh protection switching apparatus and method. The shared mesh protection switching apparatus includes a plurality of linear protection switching processors allocated to the linear protection domains respectively and configured to provide a switching report signal in response to fault occurrence in the corresponding linear protection domains or a linear protection switching operation, and perform a function of limiting use of the shared section in response to a provided lock signal, and a mesh protection switching processor configured to select at least one linear protection domain to be limited in use of the network resources of the shared section according to a predetermined reference when the switching report signal is provided and provide the lock signal to a linear protection switching processor corresponding to the at least one selected linear protection domain.

Abstract: An Ethernet protection switching method based on a change in link status in a link aggregation sublayer is disclosed. If an Ethernet link aggregation sublayer is present on an Ethernet connection path, a link aggregation sublayer Management Entity Group (MEG) end point is assigned to the Ethernet link aggregation sublayer to generate a link aggregation message for Ethernet connection management and protection switching. When a change in link status is detected in the Ethernet link aggregation sublayer, the link-aggregation-sublayer MEG end point generates and sends the link aggregation message to an MEG end point performing Ethernet connection management and protection switching. Adequate Ethernet protection switching may be performed even in the presence of the link aggregation sublayer.

Abstract: A ring protection link (RPL) owner node in a ring network transmits a ring-automatic protection switching (R-APS) frame in a burst mode until blocked ports of all nodes except the RPL owner node have been unblocked, and, if it is determined that all the nodes have been unblocked, transmits the R-APS frame in a continuous mode. In this manner, the time required to unblock all the nodes can be reduced.

Abstract: A method in which a node of an Ethernet ring network flushes a filtering database includes operating a timer for delaying flushing of the filtering database when a topology of the ring network is changed, and flushing the filtering database when the timer is terminated. A method in which a node of an Ethernet ring network flushes a filtering database includes flushing the filtering database after receiving a protection switching frame that requests flushing of the filtering database, and forwarding a data frame in a queue state at a node and then forwarding the protection switching frame to an adjacent node. A method in which a node of an Ethernet ring network flushes a filtering database includes flushing the filtering database after receiving a protection switching frame that requests flushing of the filtering database, and deleting a data frame in a queue state at the node.

Abstract: There is provided a method for managing an Ethernet ring network of a VLAN-based bridge that includes: registering a major-ring VID (VLAN ID) in a ring port filtering database of a ring protection link owner node in accordance with a request for registering the major ring VID (VLAN ID) from an ERP (Ethernet Ring Protection) controller mounted on the ring protection link owner node of a major ring; delivering, by the ring protection link owner node, a VID registration message to other nodes which belong to the major ring through a ring port; receiving the VID registration message through the ring port and registering the major ring VID in a ring port filtering database of each node itself, by each node which belongs to the major ring; and delivering, by each node which belongs to the major ring, the VID registration message to other nodes which belong to the major ring through the ring port.

Abstract: Provided is a failure recovery method in a non-revertive mode of an Ethernet ring network. In an Ethernet ring network, link priorities between nodes or node priorities are determined based on media access control (MAC) addresses and the nodes having blocked ports are determined after failures are recovered from based on the priorities so that the blocked ports can be distributed.

Abstract: A node generates a delay measurement frame and transmits it to an adjacent node of an Ethernet ring network in order to measure a delay of the network. The node receives the delay measurement frame generated by the node from another adjacent node of the ring network, and measures a network delay by using the received delay measurement frame.

Abstract: Provided is a method for forming a customized-quality integrated transport network based on synch and asynch frames, and a transport network forming apparatus thereof. The method of the present invention includes: a) synchronizing a transmission bit rate in a network; b) when the transmission bit rate is synchronized in the network and a connection request is received, establishing a connection by determining a route and a start cycle time of the link based on a quality of the connection request and transporting it to nodes of the link; and c) transmitting data to be transported to a link of an adjacent node within the virtual cycle time when the data are synch frames; or when the data are asynch frames and the data are not transmitted within a virtual cycle time of a link to be switched, keeping the data waiting for a next cycle time.

Abstract: A method for updating a filtering database in a multi-ring network, includes: when the topology of a lower ring in a multi-ring network, in which a plurality of ring networks are connected by two ring connection nodes, is altered and the ring connection node detects the alteration in the topology of the lower ring, erasing, by the ring connection node, its filtering database; generating, by the ring connection node, a control message including a ring ID, a blockage flag, and an erasure flag; transmitting the control message in both directions of the ring; and determining, by a node which receives the control message, to erase a filtering database by referring to and correcting the blockage and erasure flag information included in the control message.

Abstract: A method for protection switching of a ring network, which includes a plurality of nodes disposed in a ring shape, includes: allowing a node adjacent to a failure link among the plurality of nodes to generate a failure protection switching frame when the failure link is generated in the ring network; allowing the node adjacent to the failure link to transmit the failure protection switching frame to an adjacent node; allowing each of the plurality of nodes to delete address lists connected with the ring network except for an external network (hereinafter referred to as subnet) from their own forwarding table; allowing each of the plurality of nodes to transmit a subnet address list protection switching frame including a subnet address list; and allowing a node receiving the subnet address list protection switching frame to update the forwarding table on the basis of the subnet address list included in the frame.

Abstract: A method and apparatus for protection switching in a ring network are provided. A method for protection switching in a ring network, which includes a first ring network having first and second connection nodes and a second ring network connected with the first ring network through the first and second connection nodes, includes: receiving, by the first connection node, first and second R-APS messages transmitted from nodes belonging to the first ring network; determining, by the first connection node, the position of closure in the first ring network by using the first and second R-APS messages and topology information; receiving, by the first connection node, a topology change signal transmitted from the second ring network; and transmitting, by the first connection node, an FDB flush message with reference to the position of closure.

Abstract: 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.