JP2009077285A - Packet ring network system and method for managing forwarding database - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce the occurrence of flooding when an interlink fault occurs and to shorten FDB relearning time when the interlink fault occurs. <P>SOLUTION: When receiving a client packet, a self-ring ID insertion means 93 inserts a self-ring ID into the client packet. In transmitting a decapsuled client packet from an intra-ring packet through an interlink, a ring ID deletion means 94 of an interlink node deletes ring IDs except the ring ID of a packet ring network which transmits the client packet to another packet ring at first out of hub-rings and sub-rings from the ring IDs inserted into the client packets. A learning means 95 learns an entry together with the ring ID of the packet ring network which transmits the client packet to the other packet ring network at first. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a packet ring network system, a forwarding database management method, an interlink node, a node, a program for an interlink node, and a program for the node. The present invention relates to a forwarding database management method, an interlink node, a node, an interlink node program, and a node program applied to a network system.

  An example of a packet ring network is RPR (Resilient Packet Ring) standardized by IEEE 802.17. RPR is a MAC layer protocol that provides access to a ring-shaped transmission medium, and can provide carrier-class high-speed failure recovery, effective utilization of network bandwidth, and shortest path transfer.

  From the viewpoint of network operation management, it is effective to operate the RPR network with multi-ring connection for the purpose of expanding the service area and limiting the failure propagation range. On the other hand, in IEEE 802.17, only a rule for a single ring is defined, and there is no rule for a multi-ring.

The RPR standardized by IEEE 802.17 will be described below.
FIG. 21 is an explanatory diagram of a network configuration example of RPR. As shown in FIG. 21, the packet ring included in the RPR network has two ringlets 101 and 102 that transfer packets in opposite directions. In the packet ring, a plurality of nodes (node devices) are connected in a ring shape. FIG. 21 shows a case where four nodes 103a, 103b, 103c, and 103d are connected to the packet ring. Each node on the packet ring is given an RPR MAC address. When a network is constructed, control packets are exchanged between the nodes, and each node collects information such as the number of hops between the nodes, and acquires network topology information.

  The RPR network is a packet ring network in which nodes are connected in a ring shape and RPR is applied.

  In addition, not only nodes in the same RPR network but also terminals (referred to as user terminals) that do not belong to the RPR network may be connected to each node (RPR node) on the packet ring. In the example shown in FIG. 21, the user terminal 104a is connected to the node 103a, and the user terminal 104b is connected to the node 103b.

  Of the ports provided in the nodes on the packet ring network, a port that transmits / receives a packet to / from a device other than the node in the same packet ring network is called a tributary port. For example, among the ports of the node 103a illustrated in FIG. 21, a port that transmits / receives a packet to / from the user terminal 104a is a tributary port.

  The RPR data packet is a data packet transferred in the RPR network according to RPR. In addition, when a packet transmitted from the user terminal (hereinafter referred to as a client packet) is transferred within the RPR network, the client packet is stored in the RPR data packet as the payload of the RPR data packet and transferred as the RPR data packet. The In this way, storing a client packet as a payload in an RPR data packet is called encapsulation, and extracting a client packet stored as a payload in an RPR data packet is called decapsulation.

  An RPR data packet standardized by IEEE 802.17 will be described. FIG. 22 is an explanatory diagram showing the RPR format. When the user terminal transmits a packet to the node, the client packet 211 is transmitted. The client packet 211 includes a MAC address (MAC DA) 212 of the user terminal that is the destination of the client packet, a MAC address (MAC SA) 213 of the source user terminal of the client packet, transmission data 214, and an FCS (Frame Check Sequence). ) 215. When a node receives a client packet from a user terminal, the node encapsulates the client packet to generate an RPR data packet 221 and transmits / receives the RPR data packet 221 between the nodes. The client packet 211 is encapsulated and stored as data 226 in the PRR data packet 221. The RPR packet 221 includes a destination node MAC address (RPR MAC SA) 225, a source node MAC address (RPR MAC DA) 224, a Base Control field 223, a TTL (Time To Live) field 222, and an FCS 227. . The Base Control field 223 includes information for specifying a ringlet used for transfer and identification information for identifying a packet type such as a control packet. The TTL field 222 is used to prevent a packet from going around the ring permanently. Details of the RPR data packet format are described in Non-Patent Document 1.

  Next, RPR data packet transmission, reception and transfer operations at each node on the ring will be described.

  First, a case of a unicast data packet (an RPR data packet transmitted by unicast) will be described. Each node receives the RPR data packet transferred on the ring. When the RPR MAC DA of the RPR data packet matches the RPR MAC address of the own node, the node deletes the RPR data packet from the ring. If the RPR MAC DA of the received RPR data packet is different from the RPR MAC address of the own node, after decrementing the TTL, the RPR data packet is sent again to the same ringlet as the received ringlet. When the transmission source node receives the unicast data packet transmitted by itself, the transmission source node deletes the unicast data packet from the ring. Each node deletes the RPR data packet from the ring when the TTL becomes 0.

  In the case of a broadcast data packet (an RPR data packet transmitted by broadcast), each node decrements the TTL of the received broadcast data packet and then forwards it to the next node. When the broadcast data packet transmission source node receives the broadcast data packet transmitted by itself, it deletes the broadcast data packet from the ring. Each node deletes the RPR packet from the ring when the TTL becomes 0.

  Next, an RPR control packet standardized by IEEE 802.17 will be described. The RPR control packet is a control packet transferred within the RPR network. Hereinafter, the RPR control packet is referred to as a control packet. In order to enable autonomous operation such as topology discovery function, protection function, OAM (Operation, Administration and Maintenance) function in all nodes belonging to RPR network, each RPR node sends control packet via data path Send and receive. The RPR node sends control packets to two ringlets and receives control packets sent by other RPRs from each ringlet. For example, the RPR node 103a illustrated in FIG. 21 transmits the control packet generated by the RPR node 103a to each of the ringlets 101 and 102. Further, the RPR node 103a receives the control packet transmitted from the other RPR node from each of the ringlets 101 and 102. In IEEE 802.17, control packets are individually defined for the above functions. The transfer of the control packet between the RPR nodes is the same as the transfer of the RPR data packet already shown.

  As a control packet for realizing an OAM (Operation, Administration and Maintenance) function, IEEE 802.17 defines an OAM control packet of Echo request / response, Flush, and Organization specific. The echo request / response packet is a packet for the purpose of confirming connection between stations, identifying a fault location, and measuring LRTT (Loop Round Trip Time), and the user can arbitrarily perform a transmission operation of the request packet. The RPR node that has received the request packet transmits a response packet to the request packet transmission source node. The Flush packet is a packet for the purpose of preventing a packet order error associated with switching of the transmission ring of the flow and measuring RRTT (Ring Round Trip Time). The user can arbitrarily perform a flush packet transmission operation. The Flush packet goes around the ring and reaches the source node. The Flush packet circulates in the ring and causes all RPR packets in the Transit buffer to be discarded for each RPR node that passes through the Flush packet. The organization specific packet is an option that can be defined by the user, and there is no function definition in IEEE 802.17.

  Next, an operation of transmitting data from the user terminal 104a connected to the node 103a to the user terminal 104b connected to the node 103b in the RPR network shown in FIG.

  Each node learns by associating the MAC SA 213 (see FIG. 22) of the transmission source user terminal encapsulated in the received RPR data packet with the transmission source RPR MAC SA 225 (see FIG. 22). An RPR MAC address database using the MAC address as a search key, that is, an FDB is held. When the user terminal 104a transmits data (client packet) to the ring, the node 103a receives the client packet. The node 103a searches the FDB (Forwarding Database) using the MAC DA 212 (see FIG. 22) in the received client packet as a search key, and the result is RPR MAC DA 224 (MAC address of the destination node. See FIG. 22). To do. Further, the node 103a sets its own MAC address to RPR MAC SA225 (MAC address of the transmission source node, see FIG. 22). Then, the client packet received from the user terminal 104a is encapsulated. Further, the node 103a searches the topology database, selects a ringlet that provides the shortest path from the transmission source node to the transmission destination node, sets a TTL value, and sends an RPR data packet to the ring.

  Further, as a result of searching the FDB, when the association between the MAC address of the user terminal as the transmission destination and the RPR MAC address corresponding to the MAC address has not been learned, the node 103a performs flooding. A broadcast address is set in the RPR MAC DA of the RPR data packet transmitted by flooding, and the RPR data packet is received by all nodes on the ring. As described above, when the RPR MAC address cannot be specified by the FDB, the client packet in which the specific MAC address is defined as the MAC DA 212 is encapsulated, and the RPR packet having the RPR MAC DA as the broadcast address is converted into the Unknown unicast packet. . Further, as a result of flooding, the client packet transmitted by the user terminal 104a is received by the transmission destination user terminal 104b. Usually, the user terminal 104b sends a reply to the user terminal 104a in the upper layer. At the time of reply, the user terminal 104b becomes the transmission source of the client packet, and the user terminal 104a becomes the transmission destination. In addition, the node 103b becomes a transmission source of the RPR packet. When a reply is made from the user terminal 104b, the correspondence between the MAC address of the user terminal 104b and the RPR MAC address of the node 103b is learned in the node 103a. Therefore, when the user terminal 104a transmits a client packet to the user terminal 104b again, the node 103a searches for the RPR MAC address of the node 103b using the MAC DA 212 included in the client packet as a key, and the search result is displayed as the RPR. As the MAC DA 224, unicast transfer can be performed.

  In addition, as a method of flooding broadcast packets to the ring, a method in which the source node sends out to any one of the ringlets and a method in which the source node sends out broadcast packets to both ringlets in advance to prevent multiple transfers. There is a method (bidirectional flooding) that transfers to the destination set above. Note that the arrival point of a packet set in advance on the ring in order to prevent multiple transfer is called a cleave point. In the case of bidirectional flooding, it is necessary to change the TTL calculation method so that packets are forwarded to all nodes and double arrival does not occur depending on whether the number of nodes in the ring is even or odd. However, since this TTL calculation method is not related to the present invention, the description thereof is omitted.

  Patent Document 1 describes a packet relay device for avoiding congestion due to FDB invalidation when a failure occurs and minimizing communication interruption time.

Patent Document 2 describes a learning table for learning a packet client transmission source address, a node ID, and a ring ID.
JP 2006-270169 A International Publication No. WO2005 / 015851 “IEEE Std 802.17-2004 Part 17: Resilient packet ring access method and physical layer specifications (PART17: Resilient packet ring (RPR) access method and physical layer specifications (EPR)”, I , Inc)

  The relay apparatus described in Patent Document 1 is an apparatus that is applied to a single ring packet network, and cannot be applied to a multi-ring network in which a plurality of packet rings are connected.

  Further, the following network system can be considered as the multi-ring network. That is, the second and third packet ring networks are connected to the first packet ring network, the interlink between the first and second packet ring networks, and the interface between the first and third packet ring networks. When there is no failure with the link, communication between the packet ring networks is performed via these interlinks, and the interlink between the first and second packet ring networks or the first and third packet rings. When a failure occurs in an interlink between networks, a network system that performs communication between packet ring networks using a packet transfer path for failure occurrence provided between the second and third packet ring networks can be considered. .

  However, in such a network system, when a failure occurs in the interlink between the first and second packet ring networks or the interlink between the first and third packet ring networks, a packet transfer path for failure occurrence Therefore, the packet communication path changes before and after the occurrence of a failure. Then, the FDB must be relearned along with a change in the communication path. As such a relearning mode, the FDB is invalidated by deleting the FDB held by all nodes of the network system, and flooding is performed when a packet transmitted by the user terminal is transferred after the FDB is invalidated. Conceivable. However, in that case, a large amount of flooding occurs from each node immediately after a failure occurs in the interlink between the first and second packet ring networks or the interlink between the first and third packet ring networks. Resulting in. Then, the communication band of the packet ring network is compressed, and normal packet transfer becomes difficult. In addition, since each node invalidates all FDBs, it takes time to re-learn FDBs.

  Accordingly, the present invention provides the second and third packet ring networks when a failure occurs in the interlink between the first and second packet ring networks or the interlink between the first and third packet ring networks. To reduce the occurrence of flooding when an interlink failure occurs and to shorten the FDB relearning time when an interlink failure occurs in a network system that performs packet transfer using a packet transfer path for failure occurrence during To do.

  The packet ring network system of the present invention has a plurality of packet ring networks in which nodes are connected in a ring shape, and transmits and receives in-ring packets encapsulating client packets transmitted from terminals outside the packet ring network within the packet ring network. A packet ring network system connected to a plurality of packet ring networks via an interlink which is a packet transfer path used for client packet transfer between the packet ring networks, and at least one set of the plurality of packet ring networks is Has a hub ring that is connected via a bypass path, which is a packet transfer path used for client packet transfer in the event of an interlink failure. A plurality of sub-rings which are packet ring networks connected to the hub ring via a bypass path to other packet ring networks connected to the hub ring via an interlink, Each hub ring and each sub-ring includes an interlink node that is a node connected to the interlink, and each node in each packet ring network has its own ring ID that is an ID of the packet ring network to which the own node belongs, and its own node The address of the interlink node in the packet ring to which the node belongs, the connection destination ring ID that is the ID of the packet ring network connected to the interlink node, and the packet ring network connected to the interlink node are viewed from the own node. If the packet ring network to which the own node belongs is connected to another packet ring network via a bypass path, the information indicating whether it corresponds to a sub ring or a hub ring is included. Packet ring information table storage means for storing a packet ring information table, which is information further including a bypass path connection destination ring ID that is an ID, an address of a node in the packet ring network, an address of a terminal, and an ID of the packet ring network Address table storage means for storing a forwarding database in association with each other, and own ring ID insertion means for inserting the own ring ID into the client packet when the own node receives the client packet. When each interlink node in the ring network transmits a client packet decapsulated from the packet in the ring received from the node in the packet ring network to which the node belongs, the interlink node is inserted into the client packet. First, the client packet is transmitted from a ring ID belonging to a combination of a hub ring and a sub ring including a packet ring network to which the own node belongs and a packet ring network connected to the own node via the interlink. Ring ID deleting means for deleting a ring ID other than the ring ID of the packet ring network transmitted to another packet ring network, and each node in each packet ring network A hub ring and a sub, including a packet ring network to which the node belongs and a packet ring network that transmits the client packet to the packet ring network via an interlink when an intra-ring packet encapsulating a client packet is received A ring ID of a packet ring network that first transmits the client packet to another packet ring network in a packet ring network belonging to a combination of rings, a source address of the packet in the ring, and a source address of the client packet Is stored in the address table storage means in association with each other.

  The forwarding database management method of the present invention has a plurality of packet ring networks in which nodes are connected in a ring shape, and transmits and receives in-ring packets encapsulating client packets transmitted from terminals outside the packet ring network within the packet ring network. A packet ring network system connected to a plurality of packet ring networks via an interlink which is a packet transfer path used for client packet transfer between the packet ring networks, and at least one set of the plurality of packet ring networks is Have a hub ring that is connected via a bypass path, which is a packet transfer path used for client packet transfer when an interlink failure occurs. A plurality of sub-rings that are packet ring networks connected to the hub ring via a bypass path to other packet ring networks connected to the hub ring via an interlink. The hub ring and each sub-ring include an interlink node that is a node connected to the interlink, and each node in each packet ring network has a self-ring ID that is an ID of the packet ring network to which the self-node belongs, The address of the interlink node in the packet ring to which the node belongs, the connection destination ring ID that is the ID of the packet ring network connected to the interlink node, and the packet ring network connected to the interlink node from the own node If the packet ring network to which the own node belongs is connected to another packet ring network via a bypass path, the information indicates whether it corresponds to a sub-ring or a hub ring. A packet ring information table storage means for storing a packet ring information table which is information further including a bypass path connection destination ring ID which is an ID of the node, an address of a node in the packet ring network, an address of a terminal, and a packet ring network In a forwarding database management method applied to a packet ring network system comprising an address table storage means for storing a forwarding database associated with an ID, each node in each packet ring network When the own node receives a client packet, the node inserts its own ring ID into the client packet, and each interlink node in each packet ring network receives it from a node in the packet ring network to which the own node belongs. When a client packet decapsulated from an intra-ring packet is transmitted via an interlink, the ring ID inserted in the client packet is connected to the packet ring network to which the own node belongs and the own node via the interlink. A packet ring network that first transmits the client packet to another packet ring network in a packet ring network belonging to a combination of a hub ring and a sub ring including the packet ring network When the ring ID other than the ring ID of the packet is deleted and each node in each packet ring network receives the packet in the ring encapsulating the client packet, the packet ring network to which the node belongs and the packet ring network A packet ring that first transmits the client packet to another packet ring network in a packet ring network that belongs to a combination of a hub ring and a sub-ring including a packet ring network that transmits the client packet via an interlink A network ring ID, a transmission source address of the packet in the ring, and a transmission source address of the client packet are associated with each other and stored in an address table storage unit.

  The interlink node of the present invention has a plurality of packet ring networks in which nodes are connected in a ring shape, and transmits and receives in-ring packets encapsulating client packets transmitted from terminals outside the packet ring network in the packet ring network. A packet ring network system, which is connected to a plurality of packet ring networks via an interlink that is a packet transfer path used for client packet transfer between packet ring networks, and at least one set of the plurality of packet ring networks includes: Has a hub ring that is connected via a bypass path, which is a packet transfer path used for client packet transfer when an interlink failure occurs. In a packet ring network system having a plurality of sub-rings that are connected to each other via a bypass path to another packet ring network that is connected to the hub ring via an interlink. In the interlink node connected to the interlink, the own ring ID that is the ID of the packet ring network to which the own node belongs, the address of the interlink node in the packet ring to which the own node belongs, and the relevant interlink node A packet ring network ID, and information indicating whether the packet ring network connected to the interlink node corresponds to a sub-ring or a hub ring when viewed from the own node. When the packet ring network to which the own node belongs is connected to another packet ring network via a bypass route, packet ring information that is information further including a bypass route connection destination ring ID that is an ID of the other packet ring network A packet ring information table storage means for storing the table, an address table storage means for storing a forwarding database in which the address of the node in the packet ring network, the address of the terminal, and the ID of the packet ring network are associated; When the client packet is received, the own ring ID insertion means for inserting the own ring ID into the client packet and the in-ring packet received from the node in the packet ring network to which the own node belongs When a decapsulated client packet is transmitted via an interlink, a packet ring network to which the own node belongs and a packet connected to the own node via the interlink from the ring ID inserted in the client packet. Ring ID deleting means for deleting a ring ID other than the ring ID of the packet ring network that first transmitted the client packet to another packet ring network in the packet ring network belonging to the combination of the hub ring and the sub ring including the ring network; When an in-ring packet encapsulating a client packet is received, the packet ring network to which the node belongs and the packet ring network A ring ID of a packet ring network that first transmits the client packet to another packet ring network among packet ring networks belonging to a combination of a hub ring and a sub-ring including a packet ring network that has transmitted a client packet; And a learning unit that associates the transmission source address of the packet with the transmission source address of the client packet and stores it in the address table storage unit.

  The node according to the present invention has a plurality of packet ring networks in which the nodes are connected in a ring shape, and transmits and receives in-ring packets encapsulating client packets transmitted from terminals outside the packet ring network in the packet ring network. A network system, which is connected to a plurality of packet ring networks via an interlink that is a packet transfer path used for client packet transfer between packet ring networks, and at least one of the plurality of packet ring networks includes an interlink A hub ring that is connected via a bypass path, which is a packet transfer path used for client packet transfer when a failure occurs, and is connected to the hub ring via an interlink. Used in a packet ring network system having a plurality of sub-rings, which are packet ring networks connected to other packet ring networks connected to a hub ring via an interlink via a bypass path A self-ring ID which is an ID of a packet ring network to which the self-node belongs, an address of an interlink node in the packet ring to which the self-node belongs, and an ID of a packet ring network connected to the inter-link node And a packet ring network to which the local node belongs, including information indicating whether the packet ring network connected to the interlink node corresponds to a sub-ring or a hub ring when viewed from the local node. A packet that stores a packet ring information table that is information further including a bypass path connection destination ring ID that is an ID of the other packet ring network when the network is connected to another packet ring network via a bypass path Ring information table storage means, address table storage means for storing a forwarding database in which the address of the node in the packet ring network, the address of the terminal, and the ID of the packet ring network are associated, and the own node receives the client packet In this case, when receiving the own ring ID insertion means for inserting the own ring ID into the client packet and the in-ring packet encapsulating the client packet, the packet ring network to which the own node belongs and the relevant packet are received. A packet ring network belonging to a combination of a hub ring and a sub-ring including a packet ring network that has transmitted the client packet via an interlink to a packet ring network, and first transmits the client packet to another packet ring network And a learning unit that stores the ring ID of the packet ring network, the transmission source address of the packet in the ring, and the transmission source address of the client packet in association with each other and stored in the address table storage unit.

  The interlink node program of the present invention has a plurality of packet ring networks in which nodes are connected in a ring shape, and in-packet packets encapsulating client packets transmitted by terminals outside the packet ring network are stored in the packet ring network. A packet ring network system for transmitting and receiving, wherein the packet ring network is connected to a plurality of packet ring networks via an interlink which is a packet transfer path used for client packet transfer between the packet ring networks, and at least one set of the plurality of packet ring networks Has a hub ring that is connected via a bypass path, which is a packet transfer path used for client packet transfer when an interlink failure occurs. A packet ring network that is connected to a ring and has a plurality of sub-rings that are packet ring networks that are connected to other packet ring networks that are connected to a hub ring via an interlink via a bypass path In an interlink node program installed in a computer used as an interlink node connected to an interlink in a system, the computer includes a self-ring ID that is an ID of a packet ring network to which the self-node belongs, The address of the interlink node in the packet ring to which it belongs, the connection destination ring ID that is the ID of the packet ring network connected to the interlink node, and the packet connected to the interlink node When the packet ring network to which the own node belongs is connected to another packet ring network via a bypass path, including information indicating whether the trunk network corresponds to a sub-ring or a hub ring when viewed from the own node Includes a packet ring information table storage means for storing a packet ring information table which is information further including a bypass path connection destination ring ID which is an ID of the other packet ring network, an address of a node in the packet ring network, and a terminal Address table storage means for storing a forwarding database in which the address of the packet ring network and the ID of the packet ring network are associated with each other. Self-ring ID insertion processing for inserting a self-ring ID; when a client packet decapsulated from a packet in a ring received from a node in a packet ring network to which the self-node belongs is transmitted via an interlink, inserted into the client packet The first client in a packet ring network belonging to a combination of a hub ring and a sub-ring including a packet ring network to which the own node belongs and a packet ring network connected to the own node via the interlink. Ring ID deletion processing that deletes a ring ID other than the ring ID of the packet ring network that sent the packet to another packet ring network, and in the ring that encapsulates the client packet A packet ring network belonging to a combination of a hub ring and a sub-ring including a packet ring network to which the node belongs and a packet ring network that transmits the client packet to the packet ring network via an interlink when the packet is received The address table is stored in association with the ring ID of the packet ring network that first transmitted the client packet to another packet ring network, the source address of the packet in the ring, and the source address of the client packet. A learning process stored in the means is executed.

  The node program of the present invention includes a plurality of packet ring networks in which nodes are connected in a ring shape, and transmits and receives in-ring packets encapsulating client packets transmitted from terminals outside the packet ring network within the packet ring network. A packet ring network system, which is connected to a plurality of packet ring networks via an interlink that is a packet transfer path used for client packet transfer between packet ring networks, and at least one set of the plurality of packet ring networks includes: Has a hub ring that is connected via a bypass path, which is a packet transfer path used for client packet transfer when an interlink failure occurs. In a packet ring network system having a plurality of sub-rings that are connected to each other via a bypass path to another packet ring network that is connected to the hub ring via an interlink. In a node program installed in a computer used as a node used in the above-mentioned computer, the computer has its own ring ID that is an ID of a packet ring network to which the own node belongs and an address of an interlink node in the packet ring to which the own node belongs. And a connection destination ring ID which is an ID of a packet ring network connected to the interlink node, and a packet ring network connected to the interlink node as viewed from the own node If the packet ring network to which the own node belongs is connected to another packet ring network via a bypass path, the ID of the other packet ring network is included. Corresponding packet ring information table storage means for storing a packet ring information table which is information further including a bypass path connection destination ring ID, a node address in the packet ring network, a terminal address, and a packet ring network ID Address table storage means for storing the attached forwarding database, and when the own node receives the client packet, the own ring ID insertion process for inserting the own ring ID into the client packet; When receiving an intra-ring packet encapsulating a client packet, a hub ring and a sub that include a packet ring network to which the node belongs and a packet ring network that transmits the client packet to the packet ring network via an interlink. A ring ID of a packet ring network that first transmits the client packet to another packet ring network in a packet ring network belonging to a combination of rings, a source address of the packet in the ring, and a source address of the client packet And a learning process for storing them in the address table storage means in association with each other.

  According to the present invention, each node stores the address of the node and the address of the terminal together with the ID of the packet ring network in the address table storage means. Therefore, the node address and the terminal address can be managed by the packet ring network ID. Therefore, the occurrence of flooding when an interlink failure occurs can be reduced, and the FDB relearning time when an interlink failure occurs can be shortened.

  Embodiments of the present invention will be described below with reference to the drawings.

Embodiment 1. FIG.
FIG. 1 is an explanatory diagram showing an example of a packet ring network system according to the present invention. The packet ring network system illustrated in FIG. 1 has a configuration in which the first to third packet ring networks 5001, 5002, and 5003 are connected via links. Each of the first to third packet ring networks 5001, 5002, and 5003 is an RPR network. In each of the first to third packet ring networks 5001, 5002, and 5003, a plurality of RPR nodes are connected in a ring shape. Hereinafter, the first to third packet ring networks are referred to as a first ring, a second ring, and a third ring, respectively.

  The first ring 5001 and the second ring 5002 are connected via an interlink 5012. Similarly, the first ring 5001 and the third ring 5003 are also connected via the interlink 5011. An interlink is a packet transfer path used for client packet transfer between packet ring networks. In addition, the second ring 5002 and the third ring 5003 are used for a failure occurrence packet transfer path (used for client packet transfer when a failure occurs in an interlink connecting the first ring and another ring ( Hereinafter, this is referred to as a bypass route.) The bypass path is used to transfer a client packet when a failure occurs in the interlink between one of the two packet ring networks connected by the bypass path and the first ring.

  Hereinafter, a node connected via an interlink is referred to as an interlink node. A node connected via the bypass path is referred to as a bypass path node. Other nodes are referred to as basic nodes. In FIG. 1 etc., an interlink node is shown in black, a bypass route node is shown in diagonal lines, and a basic node is shown in white.

  In the first ring 5001, interlink nodes 1a and 1b and basic nodes 1c to 1e are connected in a ring shape. In the second ring 5002, the interlink node 2a, the bypass route node 2d, and the basic nodes 2b and 2c are connected in a ring shape. Similarly, in the third ring 5003, the interlink node 3a, the bypass route node 3b, and the basic nodes 3c and 3d are connected in a ring shape.

  The interlink node 1a of the first ring and the interlink node 2a of the second ring constitute an interlink connection by connecting the tributary ports. The same applies to the interlink node 1b of the first ring and the interlink node 3a of the third ring. The bypass ring node 2d of the second ring and the bypass path node 3b of the third ring constitute a bypass connection by connecting the tributary ports to each other.

  All of the nodes (RPR nodes) 1a to 1e, 2a to 2d, and 3a to 3d shown in FIG. 1 have an RPR function conforming to IEEE 802.17, and the interlink node and the bypass path node are each a standard RPR. In addition to the functions, it has components to operate as an interlink node and a bypass route node. In addition, the network system illustrated in FIG. 1 starts packet communication through the bypass path 5010 when a failure occurs in any of the interlinks 5012 and 5011 that connect the first ring and another ring. Since the communication start operation by the bypass path is performed separately from the operation of the present invention, the description of the node configuration and operation flow for performing the communication start operation by the bypass path is omitted.

Next, the ring ID and the name of the ring will be described.
The ring ID is identification information of each ring. Each packet ring (hereinafter, ring) included in the packet ring network system has a ring ID. For example, in FIG. 1, a ring ID is assigned to each ring, such as # 1 for the first ring.

  A ring that is directly connected to a plurality of rings via an interlink, and in which at least one of the plurality of rings is connected by a bypass path, is referred to as a hub ring. The hub ring has a plurality of interlinks. In the example shown in FIG. 1, the first ring is a hub ring.

  A ring that is directly connected to a hub ring via an interlink, and in which a bypass path is provided between the hub ring and another ring that is directly connected via the interlink, is referred to as a sub-ring. Called. In the example shown in FIG. 1, the second ring and the third ring are sub-rings for the first ring (hub ring). A plurality of sub-rings having connectivity to a common hub ring have a bypass path established between the sub-rings. In the example shown in FIG. 1, a bypass path is provided between the second ring and the third ring.

  The names of the hub ring and the sub-ring indicate a relative relationship, and are determined by an interlink to be noticed (interlink that is substituted for communication on the bypass path when a failure occurs). For example, in the packet ring network system illustrated in FIG. 16, when attention is paid to the interlink 0003 and the first ring is designated as the hub ring, the second route connected to the bypass path 0004 in light of the above definition. The ring and the third ring are sub-rings. On the other hand, when paying attention to the interlink 0001 and designating the second ring as a hub ring, the fourth ring and the fifth ring connected by the bypass route 0002 are sub-rings.

  The present invention relates to a packet ring network system including two sub-rings connected by a bypass route serving as an alternative route when an interlink failure occurs and three rings including their hub rings.

  In the first embodiment, the multi-layer configuration illustrated in FIG. 16 is not used, and other sub-rings having the sub-ring as a hub ring are not connected to the lower layer of the sub-ring. In other words, the packet ring network system of the first embodiment includes only one hub ring and a plurality of sub-rings connected to the one hub ring as the packet ring network. This is the same in the second embodiment described later.

  Further, paying attention to a certain interlink and hub ring, a sub-ring that loses connectivity through the hub ring and the interlink after the occurrence of an interlink failure is referred to as an isolated ring. That is, a sub-ring that cannot transmit / receive a packet directly to / from the hub ring due to a failure in the inter link is referred to as an isolated ring. For example, in FIG. 1, when the hub ring is designated as the first ring and a failure of the interlink 5011 is assumed, the first ring that is the hub ring and the third ring that loses connectivity through the interlink 5011 are It becomes an isolated ring. In FIG. 16, when the hub ring is designated as the first ring and a failure of the interlink 0003 is assumed, the third ring is an isolated ring. In practice, each ring set including the sixth ring and the seventh ring loses connectivity through the interlink with the first ring. Only the third ring with direct connectivity is referred to as an isolated ring. Further, when the second ring is designated as a hub ring and a failure of the interlink 0001 is assumed, the isolated ring is the fifth ring.

  FIG. 2 is a block diagram illustrating a configuration example of an interlink node. The interlink nodes 3030 shown in FIG. 2 are arranged as the interlink nodes 1a, 1b, 2a, 3a shown in FIG.

  The interlink node 3030 includes a basic configuration unit 3019 that operates according to the IEEE 802.17 standard protocol, an isolated ring determination circuit 3020, a packet ring information table storage unit 3021, an isolated ring notification packet generation circuit 3022, and an isolated ring notification packet transmission. A circuit 3023, an isolated ring notification packet receiving circuit 3024, an invalidation FDB entry determination circuit 3025, an interlink failure detection circuit 3026, and a ring ID PUSH / POP circuit 3027 are provided.

  The RPR basic node unit 3019 is provided not only for the interlink node but also for each node arranged in the RPR network.

  First, the RPR basic node unit 3019 will be described. The RPR basic node unit 3019 includes a forwarding circuit 3001 and a multiplexing circuit 3003 corresponding to the ringlet 3013-1, a forwarding circuit 3002 and a multiplexing circuit 3004 corresponding to the ringlet 3013-2, a control packet processing circuit 3017, A topology management circuit 3007, a multiplexing circuit 3005, a ringlet selection circuit 3006, a packet conversion circuit 3011, an address table storage unit 3010, and a MAC / PHY circuit 3015 are provided.

  The forwarding circuit 3001 refers to the RPR MAC DA of the RPR packet transferred from the ringlet 3013-1. If the RPR MAC DA matches the RPR MAC address of the own node, the RPR packet is extracted from the ringlet 3013-1 and sent to the multiplexing circuit 3005 for transfer to the client. Similarly, the forwarding circuit 3002 refers to the RPR MAC DA of the RPR packet transferred from the ringlet 3013-2. If the RPR MAC DA matches the RPR MAC address of its own node, the RPR MAC DA The packet is extracted from the ringlet 3013-2 and sent to the multiplexing circuit 3005. Note that taking out (deleting) a packet transferred from the ringlet from the ring and transferring it to the client is referred to as “Stripping”. A client is a device connected via a tributary port. The client of the interlink node is an interlink node arranged in another RPR network.

  When the transferred RPR packet is a broadcast packet, the forwarding circuits 3001 and 3002 transmit the broadcast packet to the multiplexing circuit 3005 and also transfer it to the ringlet. Transfer of a packet transferred from a ringlet to the ringlet is referred to as “Transit”. Also, “Copy” refers to transferring a packet transferred from a ringlet to the client while transferring the packet to the client. The forwarding circuits 3001 and 3002 transmit the forwarded packet to the same ringlet when the forwarded RPR packet does not correspond to any of the above (when the addresses do not match and are not broadcast packets) (Transit) ).

  Further, when receiving the control packet, the forwarding circuits 3001 and 3002 output the control packet to the control packet processing circuit 3017.

  The port 3922-1 is a port through which the forwarding circuit 3001 receives a packet from the ringlet 3013-1, and the port 3014-2 is a port through which the forwarding circuit 3002 receives a packet from the ringlet 3013-2. The port 3014-1 is a port through which the multiplexing circuit 3003 transmits a packet to the ringlet 3013-1, and the port 3922-2 is a port through which the multiplexing circuit 3004 transmits a packet to the ringlet 3013-2.

  In addition, the client ports 3012-1 and 3012-2 of the interlink node are connected to the client ports of other interlink nodes connected via the interlink.

  The MAC / PHY circuit 3015 receives a client packet from the port 3012-1 and sends the client packet to the packet conversion circuit 3011. The MAC / PHY circuit 3015 transmits the client packet sent from the packet conversion circuit 3011 from the port 3012-2.

  Further, the MAC / PHY circuit 3015 included in the interlink node of the present invention transmits the isolated ring notification packet generated by the isolated ring notification packet generation circuit 3022. Further, when an isolated ring notification packet is transmitted from an interlink node connected via an interlink, the MAC / PHY circuit 3015 included in the interlink node receives the isolated ring notification packet.

  The multiplexing circuit 3005 multiplexes the packets transferred from each ringlet (each forwarding circuit 3001, 3002) to the client, and sends it to the packet conversion circuit 3011.

  The address table storage unit 3010 is a storage device that stores an address table. FIG. 3 is an explanatory diagram illustrating an example of an address table. The address table learned in the present invention is information in which the MAC address of the user terminal (not shown in FIG. 1), the RPR MAC address of the node in the ring, and the ring ID are associated with each other. This ring ID is the first among the rings belonging to the combination of the hub ring and the sub-ring including the ring and the ring that transmitted the client packet via the interlink to the ring. The ring ID of the ring to be transmitted to The address table is used as an FDB.

  The packet conversion circuit 3011 receives a packet transferred from each ringlet (each forwarding circuit 3001, 3002) to the client via the multiplexing circuit 3005. The packet conversion circuit 3011 receives the packet in the RPR packet state, and extracts the client packet from the RPR packet (that is, performs decapsulation). The packet conversion circuit 3011 transfers the client packet from the port 3012-2 to the client. Further, the packet conversion circuit 3011 learns the correspondence between the RPR MAC SA in the received RPR packet and the MAC SA and ring ID in the extracted client packet, and records them in the address table storage unit 3010. The MAC SA in the extracted client packet is the MAC address of the user terminal that transmitted the client packet. As described above, the ring ID is the first of the client packets among the rings belonging to the combination of the hub ring and the sub-ring including the self ring and the ring that transmitted the client packet to the self ring via the interlink. Is the ring ID of the ring that transmits to the other ring. For example, the basic node 3c of the third ring shown in FIG. 1 receives a client packet from a user terminal (not shown in FIG. 1), broadcasts the client packet, and as a result, each client in the second ring. Assume that the node receives an RPR packet encapsulating the client packet. Each node in the second ring has a hub ring and sub-ring combination (ie, a second ring) and a first ring that has transmitted client packets over the interlink to the own ring (ie, Among the rings belonging to the first to third ring combinations), a ring ID for first transmitting a client packet to another ring is learned. In this example, since the third ring will first send client packets to the first ring, each node in the second ring will have the ring ID of the third ring along with the RPR MAC SA and MAC SA. Is stored in the address table storage unit 3010.

  The packet conversion circuit 3011 receives a client packet from the client via the client port 3012-1. At this time, the packet conversion circuit 3011 refers to the address table stored in the address table storage unit 3010 and searches for the RPR MAC address corresponding to the MAC DA in the received client packet. If there is an entry (that is, if the search is successful), the packet conversion circuit 3011 encapsulates the client packet with the searched RPR MAC address as RPR MAC DA.

  If there is no entry (that is, if the search fails), the client packet is encapsulated with the broadcast address as RPR MAC DA (in this case, an Unknown unicast packet is created). The packet conversion circuit 3011 outputs the packet encapsulated by setting the RPR MAC DA to the ringlet selection circuit 3006.

  When the packet transmitted from the packet conversion circuit 3011 is a unicast packet, the ringlet selection circuit 3006 refers to the topology management circuit 3007 to select a ringlet that can reach the destination node through the shortest path, and TTL Set to output packet. In addition, when the packet transmitted from the packet conversion circuit 3011 is a broadcast packet (including an unknown unicast packet), the ringlet selection circuit 3006 determines a predetermined transfer method (one-way flooding or two-way flooding). To select a ringlet, set TTL, and output a packet.

  The topology management circuit 3007 stores and manages the RPR MAC addresses of the nodes arranged in the clockwise direction in the ring including the own node and the RPR MAC addresses of the nodes arranged in the counterclockwise direction.

  The control packet processing circuit 3017 generates various control packets and transmits the control packets via a multiplexing circuit corresponding to the transmission target ringlet of the packets. Further, when a control packet is received from the forwarding circuits 3001 and 3002, processing corresponding to the control packet is performed.

  The multiplexing circuit 3003 multiplexes the packet from the port 3012-1 and the packet from the ring (the packet output from the forwarding circuit 3001), and transmits the multiplexed packet to the ringlet 3013-1. Similarly, the multiplexing circuit 3004 multiplexes the packet from the port 3012-1 and the packet from the ring (the packet output from the forwarding circuit 3002), and transmits the multiplexed packet to the ringlet 3013-2.

Next, components other than the RPR basic node unit 3019 will be described.
The packet ring information table storage unit 3021 stores a packet ring information table. The packet ring information table includes the ring ID information of the packet ring to which the own node (here, the interlink node itself holding the packet link information table), the bypass path connection destination ring ID information, and the packet ring in which the own node belongs. It includes all interlink node address information and ring ID information of the ring to which each interlink node is connected. However, there may be a state in which some of the entries are not present. For example, since the interlink node in the hub ring is not connected to another ring by the bypass route, there is no entry of bypass route connection destination ring ID information.

  The packet ring information table stored in the packet ring information table storage unit 3021 may be manually set by an administrator when the system is activated. Further, it may be set by a personal computer or a server. The contents of the packet ring information table of a plurality of interlink nodes in the same ring are the same.

  FIG. 4 is an explanatory diagram showing the data structure of the packet ring information table. “Own ring ID” is a ring ID of the packet ring to which the own node (here, the interlink node itself holding the packet link information table) belongs. For example, in the example shown in FIG. 4, the own ring ID is # 1 in the packet link information table held by the interlink nodes 1a and 1b belonging to the first ring (see FIG. 4A). In the packet link information tables held by the interlink node 2a belonging to the second ring and the interlink node 3a belonging to the third ring, the own node IDs are # 2 and # 3, respectively (FIG. 4 (b ), (C)).

  The “bypass path connection destination ring ID” is a ring ID of another ring connected to the packet ring to which the own node belongs via the bypass path. For example, in the packet link information table held by the interlink node 2a belonging to the second ring, the “bypass path connection destination ring ID” is # 3 (see FIG. 4B). If the packet ring to which the node belongs is not connected to another packet ring via the bypass route, the “bypass route connection destination ring ID” has no entry (see FIG. 4A).

  The “interlink node address” is an address of all interlink nodes in the packet ring to which the own node belongs. The “interlink node address” is associated with the ring ID of the connection destination ring to which the interlink node is connected via the interlink. The ring ID of the connection destination ring associated with the “interlink node address” is distinguished as to whether the connection destination ring is a lower layer ring or an upper layer ring. As shown in FIG. 4, when “upper layer ring ID” and “lower layer ring ID” are provided as items corresponding to “interlink node address” and the connection destination ring is a lower layer ring, the ring ID Is set as “lower layer ring ID”. When the connection destination ring is an upper layer ring, the ring ID is set as “upper layer ring ID”.

  Here, when a ring corresponding to a sub-ring exists when the ring to which the node belongs is viewed as a hub ring, they are defined as lower layer rings, and interlink nodes having connectivity to those lower layer rings are defined. The ring ID of the connection destination ring is defined as “lower layer ring ID”. That is, if the RPR node that sets the packet ring information table belongs to the hub ring, and the interlink node in the hub ring is connected to the sub ring, the “corresponding to the“ interlink node address ”in the packet ring information table”. The ring ID of the sub-ring is set in the “lower layer ring ID”. When there is no ring corresponding to the sub-ring or when the connection destination ring of the interlink node in the ring to which the own node belongs cannot be a sub-ring, the “lower layer ring ID” corresponding to the “interlink node address” is No entry.

  In addition, when a ring corresponding to a hub ring exists when the ring to which the own node belongs is viewed as a sub-ring, it is defined as an upper layer ring, and a connection destination of an interlink node having connectivity to the upper layer ring The ring ID of the ring is defined as “upper layer ring ID”. That is, if an RPR node that sets a packet ring information table belongs to a sub-ring and an interlink node in the sub-ring is connected to a hub ring, it corresponds to an “interlink node address” in the packet ring information table. The ring ID of the sub-ring is set in “upper layer ring ID”. If there is no ring corresponding to the hub ring, or if the connection destination ring of the interlink node in the ring to which the own node belongs cannot be a hub ring, the “upper layer ring ID” corresponding to the “interlink node address” has no entry. And

  Specific examples are shown below. For example, the interlink nodes 1a and 1b belonging to the first ring that is a hub ring are connected to the second ring and the third ring that are sub-rings via the interlink, respectively. Therefore, in the RPR node in the first ring, in the packet link information table, the ring ID (for example, # 3) of the connection ring together with the address of the interlink node in the first ring (for example, 1b) “Ring ID” is set (see FIG. 4A). The interlink node 2a belonging to the second ring is connected to the first ring, which is a hub ring, via the interlink. Therefore, in the RPR node in the second ring, in the packet link information table, the ring ID (# 1) of the connection ring is set as “upper layer ring ID” together with the address 2a of the interlink node in the second ring. It is set (see FIG. 4B).

  The contents of the packet ring information table stored in the packet ring information table storage unit 3021 are referred to by the invalidated FDB entry determination circuit 3025, the isolated ring determination circuit 3020, and the ring ID PUSH / POP circuit 3027.

The interlink failure detection circuit 3026 will be described.
The interlink failure detection circuit 3026 receives a link disconnection notification of the tributary port connected to the interlink from the MAC / PHY circuit 3015, and detects an interlink failure. Also, the isolated ring determination circuit 3020 is notified by detecting the interlink failure. In addition,
The MAC / PHY circuit 3015 may detect that a failure has occurred in the interlink due to the light input from the tributary port being cut off, and notify the interlink failure detection circuit 3026. However, this failure detection mode is an example, and the detection mode of the interlink failure is not limited to the method described here.

  The isolated ring notification packet generation circuit 3022 will be described. When the isolated ring notification packet generation circuit 3022 receives a notification of an isolated ring ID (ring ID of a ring that has become an isolated ring) from the isolated ring determination circuit 3020, the isolated ring ID is notified to a node other than its own node. An isolated ring notification packet storing the ring ID is generated. The isolated ring notification packet generation circuit 3022 outputs the generated isolated ring notification packet to the isolated ring notification packet transmission circuit 3023.

  The isolated ring notification packet transmission circuit 3023 will be described. The isolated ring notification packet transmission circuit 3023 receives the isolated ring notification packet from the isolated ring notification packet generation circuit 3022 and outputs the isolated ring notification packet to the control packet processing circuit 3017. At this time, the control packet processing circuit 3017 transmits the isolated ring notification packet from one or both of the multiplexing circuits 3003 and 3004 to the packet ring. Also, the isolated ring notification packet transmission circuit 3023 outputs the isolated ring notification packet to the MAC / PHY circuit 3015. At this time, the MAC / PHY circuit 3015 transmits an isolated ring notification packet from the tributary port to the interlink.

  The isolated ring notification packet receiving circuit 3024 will be described. The isolated ring notification packet receiving circuit 3024 receives the isolated ring notification packet transmitted to the own node from other than the own node by the control packet processing circuit 3017 and the MAC / PHY circuit 3015. That is, the control packet processing circuit 3017 outputs an isolated ring notification packet receiving circuit 3024 to the isolated ring notification packet receiving circuit 3024 when receiving an isolated ring notification packet transmitted from other than its own node to the own node from the forwarding circuits 3001 and 3002. 3024 receives the isolated ring notification packet. Similarly, when the MAC / PHY circuit 3015 receives the isolated ring notification packet transmitted to the node, the MAC / PHY circuit 3015 outputs the isolated ring notification packet to the isolated ring notification packet receiving circuit 3024. The isolated ring notification packet receiving circuit 3024 receives the isolated ring notification packet. Receive.

  Further, the isolated ring notification packet receiving circuit 3024 reads the isolated ring ID from the received isolated ring notification packet and outputs it to the isolated ring determination circuit 3020 and the invalidated FDB entry determination circuit 3025.

  The isolated ring determination circuit 3020 will be described. The isolated ring determination circuit 3020 acquires the isolated ring ID from the isolated ring notification packet receiving circuit 3024. Further, the isolated ring determination circuit 3020 obtains information on the interlink failure status of the own interlink node from the interlink failure detection circuit 3026. The isolated ring determination circuit 3020 uniquely identifies an isolated ring with reference to the information of the isolated ring ID and the interlink failure state and the packet ring information table. The process for specifying an isolated ring will be described later.

  When an isolated ring is identified, the isolated ring determination circuit 3020 notifies the isolated ring notification packet generation circuit 3022 of the ring ID (isolated ring ID) of the isolated ring, and generates an isolated ring notification packet in the isolated ring notification packet generation circuit 3022. Let As a result, the isolated ring notification packet generation circuit 3022 generates an isolated ring notification packet including the isolated ring ID, and the isolated ring notification packet transmission circuit 3023 transmits the isolated ring notification packet to another node.

  When the isolated ring is identified, the isolated ring determination circuit 3020 notifies the invalidated FDB entry determination circuit 3025 of the isolated ring ID.

  The invalidation FDB entry determination circuit 3025 will be described. The invalidation FDB entry determination circuit 3025 receives the notification of the isolated ring ID from the isolated ring determination circuit 3020, further identifies the FDB entry to be invalidated with reference to the packet ring information table, and identifies the identified entry in the address table. Disable (for example, delete). Processing for specifying the FDB entry to be invalidated will be described later.

  The ring ID PUSH / POP circuit 3027 will be described. In the ring ID PUSH / POP circuit 3027, the RPR packet is input from the multiplexing circuit 3005 to the packet conversion circuit 3011, decapsulated in the packet conversion circuit 3011, and sent to the tributary port as a client packet via the MAC / PHY circuit 3015. In the processing of the output packet, the ring ID shim header inserted immediately before the payload of the client packet is deleted (POP). For example, when the packet conversion circuit 3011 decapsulates the client packet from the RPR packet, the ring ID PUSH / POP circuit 3027 deletes the ring ID shim header from the client packet.

  In the present embodiment, when adding ring ID information to a client packet, it is added as a shim header, and a newly added ring ID shim header is inserted immediately before the payload of the client packet.

  Further, the ring ID PUSH / POP circuit 3027 receives a client packet from the tributary port via the MAC / PHY circuit 3015 and outputs it to the multiplexing circuit 3005 after RPR encapsulation. A ring ID shim header is inserted (PUSH) immediately before the payload of the client packet. For example, when a client packet is input to the packet conversion circuit 3011, a ring ID shim header is inserted immediately before the payload of the client packet. The ring ID PUSH / POP circuit 3027 refers to the “own ring ID” included in the packet ring information table and inserts the ring as a shim header.

  The operation of adding and deleting shim headers by the ring ID PUSH / POP circuit 3027 will be described later with reference to FIG.

  Next, the configuration of the basic node and the bypass route node will be described. In addition to the same components as the basic node, the bypass path node transitions the tributary port from the blocked state to the open state when receiving an interlink failure notification, and links up the bypass path from the standby state. However, since these operations are performed separately from the operations of the present invention, description of the components of the bypass path node that performs these operations is omitted. Here, the basic node will be described as an example. However, all the constituent elements of the basic node are also provided in the bypass route node, and the following description regarding the basic node also applies to the bypass route node.

  FIG. 5 is a block diagram illustrating a configuration example of the basic node. The basic node and bypass path node shown in FIG. 1 have the same configuration as the basic node 4030 shown in FIG.

  The basic node 4030 includes an RPR basic node unit 3019, a packet ring information table storage unit 4021, an isolated ring notification packet reception circuit 4024, an invalidation FDB entry determination circuit 4025, and a ring ID PUSH / POP circuit 3027.

  The configuration of the RPR basic node unit 3019 of the basic node is the same as the configuration of the RPR basic node unit 3019 of the interlink node. Each component provided in the RPR basic node unit 3019 is represented by the same reference numeral as in FIG. The operation of the ring ID PUSH / POP circuit 3027 provided in the basic node is the same as the operation of the ring ID PUSH / POP circuit 3027 provided in the interlink node.

  Similar to the packet ring information table storage unit 3021 of the interlink node, the packet ring information table storage unit 4021 of the basic node is a storage device that stores the packet ring information table. The packet ring information table stored in the packet ring information table storage unit 4021 of the basic node and the bypass route node includes “own ring ID (ring ID of the packet ring to which the own node belongs)” and “bypass route connection destination ring ID (self It is only necessary to include the packet ring to which the node belongs and the ring ID of another ring connected via a bypass route. If the packet ring to which the node belongs is not connected to another packet ring via the bypass route, the “bypass route connection destination ring ID” has no entry. The contents of the packet ring information tables of a plurality of basic nodes and bypass path nodes in the same ring are the same. The packet ring information table stored in the packet ring information table storage unit 4021 may be manually set by an administrator when the system is activated. Further, it may be set by a personal computer or a server.

  The isolated ring notification packet receiving circuit 4024 will be described. The isolated ring notification packet receiving circuit 4024 receives the isolated ring notification packet transmitted to the own node from other than the own node by the control packet processing circuit 3017. That is, the control packet processing circuit 3017 outputs an isolated ring notification packet received from the forwarding circuits 3001 and 3002 to the isolated ring notification packet receiving circuit 4024 when receiving an isolated ring notification packet transmitted from other than the own node to the own node. 4024 receives the isolated ring notification packet. Also, the isolated ring notification packet receiving circuit 4024 reads the isolated ring ID from the received isolated ring notification packet and outputs it to the invalidated FDB entry determination circuit 3025.

  The invalidation FDB entry determination circuit 4025 will be described. The invalidation FDB entry determination circuit 4025 receives the notification of the isolated ring ID from the isolated ring notification packet reception circuit 4024, further identifies the FDB entry to be invalidated by referring to the packet ring information table, and identifies the address table. Invalidate (eg delete) the entry. Processing for specifying the FDB entry to be invalidated will be described later.

  It should be noted that all the components such as the basic node and the interlink node may be provided in one node so that the one node can be used as either the basic node or the interlink node. For example, it is possible to set the interlink node operation mode, the basic node operation mode, etc., and when the basic node operation mode is set, do not operate the components used only in the interlink node among the components provided in the node. By doing so, it may be operated as a basic node. When the interlink node operation mode is set, each component (see FIG. 2) required as an interlink node may be operated.

Next, the operation will be described.
First, an operation in which each node transfers an RPR packet received from an adjacent RPR node to the next RPR node will be described. When the RPR MAC DA receives an RPR packet having an address other than its own node or a broadcast address, the forwarding circuit 3001 transmits it to the next RPR node via the multiplexing circuit 3003. The same applies to the forwarding circuit 3002. Note that the RPR packet whose RPR MAC DA is the broadcast address is also output to the multiplexing circuit 3005 for COPY. The operation in this case will be described later.

  Next, an operation in which each node encapsulates the client packet received from the tributary port and transmits it in the ring will be described.

  When receiving the client packet from the tributary port, the MAC / PHY circuit 3015 outputs the client packet to the packet conversion circuit 3011. The packet conversion circuit 3011 outputs the client packet to the ring ID PUSH / POP circuit 3027.

  FIG. 6A is a flowchart illustrating an example of ring ID shim header addition processing. The above operation corresponds to step S1 shown in FIG. When the ring ID PUSH / POP circuit 3027 receives the client packet received by the tributary port, the ring ID PUSH / POP circuit 3027 determines whether or not a ring ID (ring ID shim header) is attached (inserted) immediately before the client packet (step S2). . When the ring ID is inserted, the ring ID PUSH / POP circuit 3027 adds the “own ring ID” included in the packet ring information table as a ring ID shim header. In this embodiment, since the last added ring ID shim header is inserted immediately before the payload, the own ring ID is inserted between the already inserted ring ID and the payload (step SS3). Further, in the present embodiment, two or more ring IDs are not given to client packets received at the tributary port. Therefore, as a result of the processing in step S3, two ring IDs are assigned to the client packet. If the ring ID is not assigned to the client packet as a result of the determination in step S2, the ring ID PUSH / POP circuit 3027 uses the “own ring ID” included in the packet ring information table as the ring ID shim header, and Insert immediately before the payload (step S4). As a result, one ring ID is assigned to the client packet. The ring ID PUSH / POP circuit 3027 sends the client packet to which the ring ID is assigned to the packet conversion circuit 3011 (step S5).

  The packet conversion circuit 3011 refers to the address table and searches for the address of the RPR node corresponding to the destination address using the destination address (MAC DA) of the client packet as a search key. When the search is successful, the client packet is encapsulated with the address of the RPR node as RPR MAC DA. If the search fails, the client packet is encapsulated with the broadcast address as RPR MAC DA. Next, the ringlet selection circuit 3006 determines the ringlet used for transmission based on the RPR MAC DA of the RPR packet encapsulated by the packet conversion circuit 3011 and the information stored in the topology management circuit 3007, and the ringlet The RPR packet is output to one or both of the multiplexing circuits 3003 and 3004 according to the let. Multiplexing circuits 3003 and 3004 transmit the RPR packet input from ringlet selection circuit 3006 to the ringlet.

  Next, an operation of decapsulating the RPR node received by each node and transmitting from the tributary port (operation in the case of COPY or the like) will be described. When receiving the RPR packet whose RPR MAC DA is its own node address or broadcast address, the forwarding circuit 3001 outputs the RPR packet to the packet conversion circuit 3011 via the multiplexing circuit 3005. The packet conversion circuit 3011 decapsulates the client packet from the RPR packet, extracts the client packet, and outputs the client packet to the ring ID PUSH / POP circuit 3027.

  The packet conversion circuit 3011 also receives the RPR MAC SA of the received RPR packet, the MAC SA of the decapsulated client packet, and the ring ID (client packet) inserted first among the ring IDs assigned to the client packet. Is associated with the ring ID) and stored in the address table storage unit. A set of information stored in this way becomes an address table. When two ring IDs are given to the client packet, the ring ID inserted first among the two is the ring ID that is not close to the payload. Registering the ring ID first inserted in the ring ID assigned to the client packet in the address table means that if two ring IDs are assigned to the client packet, the two ring IDs are assigned. This means that the ring ID of a ring other than the ring to which the node belongs belongs to the address table. Furthermore, among the rings belonging to the combination of the hub ring and the sub-ring including the ring to which the own node belongs (that is, the own ring) and the ring to which the client packet is transmitted via the interlink to the own ring, the client first This means that the ID of the ring that transmitted the packet to another ring is registered.

  When only one ring ID is assigned to the client packet, the packet conversion circuit 3011 may register the ring ID together with the RPR MAC SA and MAC SA in the address table.

  FIG. 6B is a flowchart showing an example of the ring ID shim header deletion process. The ring ID PUSH / POP circuit 3027 receives the decapsulated client packet from the packet conversion circuit 3011 (step S11). If the own node is not an interlink node (N in step S12), the ring ID PUSH / POP circuit 3027 deletes all ring ID shim headers inserted in the client packet (step S13), and proceeds to step S18.

  If the own node is an interlink node (Y in step S12), the number of ring ID shim headers inserted in the client packet (that is, the ring ID shim header sequentially given immediately before the payload) is determined (step S14). ). If the number is 1, the process proceeds to step S18.

  When the number determined in step S14 is two, in this embodiment, the connection destination link of the own node that is the interlink node is a lower layer ring. In this case, the ring ID PUSH / POP circuit 3027 deletes one ring ID on the side close to the payload and holds the other ring ID as it is (step S17). In step S17 in this embodiment, the ring ID shim header inserted later in the ring ID assigned to the client packet is deleted. Deleting the ring ID as in step S17 means that the ring to which the own node belongs (own ring) and the ring belonging to the combination of the hub ring and the sub ring including the ring connected to the own node via the interlink. This means that the ring ID other than the ring ID of the ring that first transmitted the client packet to another ring is deleted.

  After step S17, the process proceeds to step S18. In step S18, the ring ID PUSH / POP circuit 3027 outputs the client packet to the packet conversion circuit 3011, and the packet conversion circuit 3011 transmits the client packet from the tributary port via the MAC / PHY circuit 3015.

  Next, an operation when the interlink node detects an interlink failure will be described. FIG. 7 is a flowchart illustrating an example of processing progress when an interlink node detects an interlink failure. When a failure occurs in the interlink, the MAC / PHY circuit 3015 detects the interlink failure and notifies the interlink failure detection circuit 3026. Upon receiving this notification, the interlink failure detection circuit 3026 notifies the isolated ring determination circuit 3020 that an interlink failure has occurred (step S21).

  The isolated ring determination circuit 3020 refers to the packet ring information table (step S22) and determines whether or not the connection destination ring of the interlink node (that is, its own node) that detected the interlink failure is an upper layer ring (step S22). Step 23). If the ring ID of the connection destination ring corresponding to the address of the own node is stored as the “upper layer ring ID”, the isolated ring determination circuit 3020 determines that the connection destination ring is the upper layer ring, If it is stored as “layer ring ID”, it is determined that the connection destination ring is a lower layer ring. Then, the isolated ring determination circuit 3020 determines that the ring to which the own node belongs is an isolated ring if the connection destination ring of the own node is an upper layer ring (Y in Step S23), and sets the own ring ID as a packet ring. Extracted from the information table (step S24). Further, if the connection destination ring of the own node is not the upper layer ring (N in step S23), the lower layer ring that is the connection destination ring of the interlink node (that is, the own node) that detected the interlink failure is an isolated ring. And the ring ID is extracted from the packet ring information table (step S25).

  When the isolated ring determination circuit 3020 determines the isolated ring, it notifies the invalidated FDB entry determination circuit 3025 and the isolated ring notification packet generation circuit 3022 of the isolated ring ID (the ring ID extracted in steps S24 and S25).

  The invalidation FDB entry determination circuit 3025 refers to the packet ring information table and determines whether the isolated ring ID indicates the own ring or the lower layer ring (step S26). The invalidation FDB entry determination circuit 3025 determines that the isolated ring ID indicates the own ring if the isolated ring ID is registered in the packet ring information table as the own ring ID. If the isolated ring ID is registered in the packet ring information table as the lower layer ring ID, it is determined that the isolated ring ID indicates the lower layer ring.

  The invalidation FDB entry determination circuit 3025 is connected to the ring ID of the upper layer ring of the ring to which the own node belongs and the ring to which the own node belongs via the bypass path if the isolated ring ID indicates the own ring. The ring ID of the ring to be invalidated is determined as the ring ID of the entry to be invalidated in the address table, and the entry corresponding to the ring ID is invalidated in the address table (step S27a). If the isolated ring ID indicates a lower layer ring, the invalidated FDB entry determination circuit 3025 invalidates the entry corresponding to the isolated ring ID in the address table (step S27b).

  In addition, when the isolated ring ID is notified, the isolated ring notification packet generation circuit 3022 generates an isolated ring notification packet including the isolated ring ID and outputs the isolated ring notification packet to the isolated ring notification packet transmission circuit 3023 (step S28). The isolated ring notification packet transmission circuit 3023 transmits an isolated ring notification packet from the multiplexing circuits 3003 and 3004 via the control packet processing circuit 3017 (step S29). At this time, for example, the isolated ring notification packet is transmitted using the destination address as a broadcast address so that the isolated ring notification packet reaches all nodes in the packet ring.

  Next, the operation when an interlink node other than the interlink node that detected the interlink failure receives the isolated ring notification packet will be described with reference to the flowchart shown in FIG. When the isolated ring notification packet receiving circuit 3024 of the interlink node that has not detected the interlink failure itself receives the isolated ring notification packet that has the source of the interlink node that has detected the interlink failure (step S31), The isolated ring ID is read from the ring notification packet and notified to the isolated ring determination circuit 3020 (step S32).

  When the isolated ring ID is notified from the isolated ring notification packet receiving circuit 3024, the isolated ring determination circuit 3020 indicates that the isolated ring ID in the ring to which the own node belongs in the packet ring information table. It is determined whether it is defined as “lower layer ring ID”, bypass path connection destination ring ID, or “own ring ID” (step S33).

  When the isolated ring ID is defined as the “lower layer ring ID” of any interlink node in the ring to which the node belongs, the following operation is performed. The isolated ring determination circuit 3020 notifies the isolated ring ID of the isolated ring ID to the isolated ring notification packet generation circuit 3022 and the invalidated FDB entry determination circuit 3025. The isolated ring notification packet generation circuit 3022 generates an isolated ring notification packet including the isolated ring ID (step S34) and outputs it to the isolated ring notification packet transmission circuit 3023. The isolated ring notification packet transmission circuit 3023 transmits the isolated ring notification packet from the tributary port via the MAC / PHY circuit 3015 (step S35). The invalidation FDB entry determination circuit 3025 invalidates the entry corresponding to the isolated ring ID notified from the isolated ring determination circuit 3020 in the address table (step S36).

  When the isolated ring ID is determined as the bypass path connection destination ring ID, the following operation is performed. The isolated ring determination circuit 3020 notifies the isolated ring ID of the isolated ring ID to the isolated ring notification packet generation circuit 3022 and the invalidated FDB entry determination circuit 3025. The isolated ring notification packet generation circuit 3022 generates an isolated ring notification packet including the isolated ring ID (step S37) and outputs it to the isolated ring notification packet transmission circuit 3023. The isolated ring notification packet transmission circuit 3023 transmits the isolated ring notification packet, for example, using the destination address as a broadcast address so that the isolated ring notification packet reaches all nodes in the packet ring (step S38). This operation is the same as step S29. The invalidation FDB entry determination circuit 3025 invalidates the entry corresponding to the isolated ring ID notified from the isolated ring determination circuit 3020 in the address table (step S36).

  When the isolated ring ID is defined as “own ring ID”, the following operation is performed. The isolated ring determination circuit 3020 notifies the isolated ring ID to the invalidated FDB entry determination circuit 3025. The invalidation FDB entry determination circuit 3025 invalidates the ring ID of the upper layer ring of the ring to which the own node belongs and the ring ID of the ring connected to the ring to which the own node belongs via the bypass path in the address table. The entry is determined as a ring ID, and the entry corresponding to the ring ID is invalidated in the address table (step S39).

  Next, the operation when a node other than the interlink node (basic node and bypass route node) receives the isolated ring notification packet will be described with reference to the flowchart shown in FIG. Here, the basic node is described as an example, but the operation of the bypass path node is the same. When the isolated ring notification packet receiving circuit 4024 of the basic node receives the isolated ring notification packet, it reads the isolated ring ID from the isolated ring notification packet and notifies the invalidated FDB entry determination circuit 4025 (step S41).

  If the isolated ring ID notified from the isolated ring notification packet receiving circuit 4024 does not match the “own ring ID” in the packet ring information table, the invalidation FDB entry determination circuit 4025 displays the isolated ring ID in the address table. The entry corresponding to the ID is invalidated (step S42). If the notified isolated ring ID matches the “own ring ID”, the invalidation FDB entry determination circuit 4025 displays the ring ID of the upper layer ring of the ring to which the own node belongs and the ring to which the own node belongs. The ring ID of the ring connected via the bypass path is defined as the ring ID of the entry to be invalidated in the address table, and the entry corresponding to the ring ID is invalidated in the address table (step S43).

  FIG. 10 is an explanatory diagram illustrating a situation where a ring ID and the like included in an FDB (address table) are learned. Hereinafter, referring to the flowcharts of FIGS. 6 to 9 and FIG. 10 and the like, FDB learning of the client packet transmission source ring ID, identification and notification of the isolated ring when an interlink failure occurs, and identification and recognition of the isolated ring The subsequent FDB entry erasing operation will be described with a specific example.

  The packet ring network system illustrated in FIG. 10 is similar to the packet ring network system illustrated in FIG. 1 and includes a first ring, a second ring, and a third ring. Then, the first ring and the second ring are connected by the interlink nodes 1a and 2a and the interlink 5012. The first ring and the third ring are connected by the interlink nodes 1b and 3a and the interlink 5011. In addition, the second ring and the third ring are connected by the bypass path nodes 2d and 3b and the bypass path 5010, but the link path is linked down in the normal state when no failure occurs in the interlink. No client packet is transferred via the bypass path. In other words, under normal conditions, the packet ring network system does not transfer packets through the bypass path 5010. When a failure occurs in any of the interlinks 5011 and 5012, the packet ring network system starts packet transfer on the bypass route 5010, and the bypass route 5010 becomes an alternative route for the interlink in which the failure has occurred. FIG. 11 is an explanatory diagram showing a change of a packet transfer path when a failure occurs in the interlink 5011. When a failure occurs in the interlink 5011 as shown in FIG. 11A, the bypass route 5010 starts to be used as a packet transfer route as shown in FIG. 11B.

  Each node of each ring is assumed to hold a packet ring information table illustrated in FIG.

  A specific example of the operation related to FDB learning of the client packet transmission source ring ID will be described. In FIG. 10, the client device A connected to the tributary port of the node 3c of the third ring transmits a client packet of DA = FF and SA = A, and sends it to the tributary port of the second ring 2c. A packet transfer process until a client packet is received by the connected client apparatus B will be described as an example. DA and SA mean a transmission destination and a transmission source. Operation until the node 2c of the second ring learns the SA (RPR MAC SA) of the RPR packet, the SA (MAC SA) of the client packet, and the client packet transmission source ring ID in the address table of the own node and constructs the table Is as follows.

  When the basic node 3c receives a client packet from the client device A, the ring ID PUSH / POP circuit 3027 of the basic node 3c performs a PUSH (insertion) operation of the ring ID shim header by the operation shown in FIG. Since the basic node receives the client packet from the client device at the tributary port, the ring ID shim header is not already added to the received client packet. Therefore, the ring ID PUSH / POP circuit 3027 refers to the own ring ID (the ring ID of the packet ring to which the own node belongs) in the packet ring information table, and inserts the ring ID = # 3 immediately before the payload of the client packet. (See step S4, FIG. 6A.) A client packet to which one ring ID shim header is attached is generated and output to the packet conversion circuit 3011 (step S5).

  Here, a case where the client packet received from the client apparatus A is encapsulated and broadcast is described as an example. The basic node 3c performs flooding by encapsulating the client packet to which the ring ID = # 3 is assigned by RPR packet transmission using a normal RPR packet transmission process. This RPR packet reaches the interlink node 3a. The interlink node 3a copies the received RPR packet, decapsulates it by normal RPR packet reception processing, and outputs a client packet to which the ring ID = # 3 is assigned from the tributary port. At this time, the ring ID PUSH / POP circuit 3027 of the interlink node 3a performs the operation shown in FIG. Here, since the ring ID assigned to the client packet is one, the ring ID is sent as it is to the tributary port without performing PUSH / POP (shift from step S14 to step S18). The tributary port of the interlink node 1b receives this client packet via the interlink 5011.

  The ring ID PUSH / POP circuit 3027 of the interlink node 1b pushes (inserts) the ring ID shim header by the operation shown in FIG. In this example, it is confirmed that the ring ID shim header (# 3) has already been added to the client packet input from the tributary port (interlink), and between the ring ID shim header already provided and the payload. Push the ring ID shim header of the ring ID = # 1 of the own ring (step S3). Therefore, a client packet with two ring ID shim headers is generated.

  The interlink node 1b performs RPR encapsulation on the client packet to which the ring ID = # 3 and # 1 are assigned by RPR packet transmission processing and floods the packet. This RPR packet reaches the interlink node 1a. The interlink node 1a copies the received RPR packet, decapsulates it by normal RPR packet reception processing, and outputs the client packet from the tributary port. At this time, the ring ID PUSH / POP circuit 3027 of the interlink node 1a deletes the ring ID by the operation shown in FIG. Here, there are two ring IDs assigned to the client packet. In this case, the connection destination of the interlink node 1a is a lower layer ring (that is, the relationship that the first ring is a hub ring and the second ring is a sub-ring), and one of the sides closer to the payload Ring ID (# 1) is deleted, and the other ring ID (# 3) is held as it is (step S17). Then, the interlink node 1a sends the client packet to the tributary port (step S18). The tributary port of the interlink node 2a receives this client packet via the interlink 5012.

  The ring ID PUSH / POP circuit 3027 of the interlink node 2a inserts the ring ID shim header by the operation shown in FIG. In this example, the client packet received from the tributary port (interlink) confirms that the shim header with ring ID = # 3 has already been assigned, and the shim header with the ring ID = # 3 already assigned and the payload During this period, the ring ID shim header of the ring ID = # 2 is pushed (step S3). Therefore, a client packet with two ring ID shim headers (ring ID = # 3 and # 2) is generated.

  The interlink node 2a performs RPR encapsulation of the client packet to which the ring IDs = # 3 and # 2 are assigned by the normal RPR packet transmission processing and floods the packet. This RPR packet reaches the basic node 2c. The basic node 2c copies the received RPR packet and decapsulates it by normal RPR packet reception processing. At that time, the packet conversion circuit 3011 of the basic node 2c learns the correspondence between the RPR packet transmission source (RPR MAC SA) and the client packet transmission source (MAC SA), and stores the learning content in the address table storage unit 3010. Record. Further, the packet conversion circuit 3011 refers to the shim header (ring ID = # 3) which is not the shim header (ring ID = # 2) provided close to the payload side of the client packet. That is, the ring ID previously inserted into the client packet is referred to. Then, the ring ID is stored in the address table storage unit 3010 in association with the RPR packet transmission source (RPR MAC SA) and the client packet transmission source (MAC SA).

  Further, the ring ID PUSH / POP circuit 3027 deletes the ring ID shim header by the operation shown in FIG. Here, since the own node is the basic node 2c and not the interlink node (N in Step S12), the ring ID PUSH / POP circuit 3027 outputs the client packet to the tributary port after POPing all the ring ID shim headers. (Steps S13 and S18). The client device B receives the client packet transmitted by the client device A.

  With the above operation, for the client packet transmitted from the client device A and the basic node 3c and received by the client device B and the basic node 2c, the source node of the RPR packet (RPR MAC SA), The client packet source (MAC SA) and client packet source ring ID are learned.

  In the above description, the broadcast transfer is described as an example for the RRP packet and the client packet, but the operation of learning the transmission source of the RPR packet, the transmission source of the client packet, and the ring ID by unicast transfer is the same. The operation when learning is performed by receiving an Unknown unicast packet is the same.

  Next, an operation for specifying an isolated ring and notifying an isolated ring ID of the specified isolated ring when an interlink failure occurs will be described. This notification operation enables notification of occurrence of an interlink failure, notification that FDB entry invalidation due to occurrence of an interlink failure is necessary, and identification of FDB entries that need to be invalidated at each node.

  The interlink node 3a is an interlink node that directly detects an interlink failure. When a failure occurs in the interlink 5011, the MAC / PHY circuit 3015 and the interlink failure detection circuit 3026 of the interlink node 3a detect the interlink failure. Then, the isolated ring determination circuit 3020 receives notification of the occurrence of an interlink failure from the interlink failure detection circuit 3026 and refers to the packet ring information table (step S22). The isolated ring determination circuit 3020 refers to the connection destination of the interlink node 3a that has detected the interlink failure, and # 1 is registered as an upper layer ring (Y in step S23). 3) and the ring ID of the isolated ring is determined as # 3 (step S24).

  Further, the isolated ring notification packet generation circuit 3022 of the interlink node 3a that has detected the interlink failure generates an isolated ring notification packet that notifies the isolated ring ID = # 3, and outputs it to the isolated ring notification packet transmission circuit 3023 (step). S28). The isolated ring notification packet transmission circuit 3023 transmits the isolated ring notification packet to all the nodes in the packet ring (third ring) to which the own node belongs (step S29).

  The interlink node 1b is an interlink node that directly detects an interlink failure. When a failure occurs in the interlink 5011, the MAC / PHY circuit 3015 and the interlink failure detection circuit 3026 of the interlink node 1b detect the interlink failure. Then, the isolated ring determination circuit 3020 receives notification of the occurrence of an interlink failure from the interlink failure detection circuit 3026 and refers to the packet ring information table (step S22). The isolated ring determination circuit 3020 refers to the connection destination of the interlink node 1b in which the interlink failure is detected, and # 3 is registered as a lower layer ring (N in step S23). The ring ID of the isolated ring is determined to be # 3 (step S25).

  Further, the isolated ring notification packet generation circuit 3022 of the interlink node 1b that has detected the interlink failure generates an isolated ring notification packet that notifies the isolated ring ID = # 3, and outputs it to the isolated ring notification packet transmission circuit 3023 (step). S28). The isolated ring notification packet transmission circuit 3023 transmits the isolated ring notification packet to all the nodes in the packet ring (first packet ring) to which the own node belongs (step S29).

  The interlink node 1a cannot directly detect the interlink failure of the interlink 5011, but can detect the failure by receiving the isolated ring notification packet from the interlink node 1b. This interlink node 1a performs the process shown in FIG. The isolated ring notification packet receiving circuit 3024 of the interlink node 1a receives the isolated ring notification packet via the control packet processing circuit 3017 (step S31), and reads the ring ID = # 3 of the isolated ring (step S32). Then, the isolated ring ID is notified to the isolated ring determination circuit 3020. The isolated ring determination circuit 3020 refers to the packet ring information table of its own node (FIG. 4A) (step S33), and the third ring that is an isolated ring is the lower layer ring of the interlink node that detected the failure. Confirm that it is registered as. The interlink node that has detected the failure may be determined from the source address (1b in this example) of the isolated ring notification packet. As shown in FIG. 4A, the ring ID = # 3 corresponding to the interlink node 1b that has detected the failure is registered as a lower layer ring. In this case, the isolated ring determination circuit 3020 notifies the isolated ring notification packet generation circuit 3022 of the ring ID = # 3 of the isolated ring. The isolated ring notification packet generation circuit 3022 sets an isolated ring ring ID = # 3 and generates an isolated ring notification packet (step S34). The isolated ring notification packet transmission circuit 3023 outputs the isolated ring notification packet to the tributary port of the interlink node 1a and transmits it to the second ring via the interlink 5012 (step S35).

  The interlink node 2a cannot directly detect an interlink failure of the interlink 5011, but can detect a failure by receiving an isolated ring notification packet from the interlink node 1a via a tributary port. This interlink node 2a performs the process shown in FIG. The isolated ring notification packet receiving circuit 3024 of the interlink node 2a receives the isolated ring notification packet via the MAC / PHY circuit 3015 (step S31), and reads the ring ID = # 3 of the isolated ring (step S32). Then, the isolated ring ID is notified to the isolated ring determination circuit 3020. The isolated ring determination circuit 3020 refers to the packet ring information table (step S33), and the third ring that is an isolated ring is registered as a bypass path connection destination ring of the packet ring to which the own node belongs. Is confirmed (see FIG. 4B). In this case, the isolated ring determination circuit 3020 notifies the isolated ring notification packet generation circuit 3022 of the ring ID = # 3 of the isolated ring. The isolated ring notification packet generation circuit 3022 sets an isolated ring ring ID = # 3 and generates an isolated ring notification packet (step S37). The isolated ring notification packet transmission circuit 3023 transmits the isolated ring notification packet to all the nodes in the packet ring (second ring) to which the own node belongs.

  With the above notification operation, an isolated ring ID can be specified, and an isolated ring ID can be notified to all the rings including a node that requires FDB invalidation.

  Next, the operation of invalidating the FDB entry in each node in the ring including the node that needs to be invalidated will be described.

  First, the nodes other than the interlink node 3a and the interlink node 3a in the third ring will be described.

  The interlink node 3a is an interlink node that can directly detect an interlink failure of the interlink 5011. The interlink node 3a is invalidated by the processing after step S26 shown in FIG. That is, when the invalidation FDB entry determination circuit 3025 of the interlink node 3a receives the notification of the isolated ring ID = # 3 from the isolated ring determination circuit 3020, it refers to the packet ring information table of its own node (FIG. 4C). Then, it is confirmed that the ring ID = # 3 matches the ring ID to which the own node belongs (step S26). In this case, the invalidated FDB entry determination circuit 3025 stores FDB entries of higher layer ring ID = # 1 and bypass path connection destination ring ID = # 2 in the address table of the own node, that is, entries other than ring ID = # 3. Or invalidate it by deleting it.

  Nodes other than the interlink node 3a in the third ring perform the operation shown in FIG. The isolated ring notification packet receiving circuit 4024 receives the isolated ring notification packet transmitted from the interlink node 3a via the control packet processing circuit 3017. Then, the isolated ring notification packet receiving circuit 4024 reads the isolated ring ID = # 3 from the isolated ring notification packet and notifies the invalidated FDB entry determination circuit 4025 of the isolated ring ID (step S41). The invalidation FDB entry determination circuit 4025 refers to the packet ring information table of the own node (FIG. 4C) and confirms that the isolated ring ID (# 3) matches the ring ID of the ring to which the own node belongs. To do. Then, the invalidation FDB entry determination circuit 4025 uses the ring ID = # 1 of the upper layer ring (first ring) and the ring ID = # of the bypass path connection destination ring (second ring) in the address table of the own node. 2 FDB entries, ie, entries other than ring ID = # 3 are invalidated by deleting them (step S43).

  Next, nodes other than the interlink nodes 1b and 1a and the interlink nodes 1b and 1a in the first ring will be described.

  The interlink node 1b is an interlink node that can directly detect an interlink failure of the interlink 5011, and is invalidated by the processing after step S26 shown in FIG. That is, when the invalidation FDB entry determination circuit 3025 of the interlink node 1b receives the notification of the isolated ring ID = # 3 from the isolated ring determination circuit 3020, it refers to the packet ring information table of its own node (FIG. 4A). Then, it is confirmed that the isolated ring ID = # 3 is a connection destination ring of the interlink node 1b where the failure is detected and is a lower layer ring (step S26). In this case, the invalidated FDB entry determination circuit 3025 invalidates only the FDB entry with the isolated ring ID = # 3 in the address table of the own node by, for example, deleting it.

  The interlink node 1a is not an interlink node that can directly detect an interlink failure of the interlink 5011, but performs the invalidation process shown in FIG. The isolated ring notification packet receiving circuit 3024 of the interlink node 1a receives the isolated ring notification packet transmitted from the interlink node 1b via the control packet processing circuit 3017, and reads the isolated ring ID = # 3 (step S31). , S32). The isolated ring determination circuit 3020 refers to the packet ring information table of its own node (FIG. 4A) (step S33), and the third ring, which is an isolated ring, connects to the interlink node 1b that detected the failure. Confirm that the ring is a lower layer ring. The interlink node 1b that has detected the failure may be determined from the source address of the isolated ring notification packet. In this case, the invalidated FDB entry determination circuit 3025 invalidates only the FDB entry with the isolated ring ID = # 3 in the address table of the own node by, for example, deleting it.

  Nodes other than the interlink nodes 1a and 1b in the first ring perform the operation shown in FIG. The isolated ring notification packet receiving circuit 4024 receives the isolated ring notification packet transmitted from the interlink node 1b via the control packet processing circuit 3017. Then, the isolated ring notification packet receiving circuit 4024 reads the isolated ring ID = # 3 from the isolated ring notification packet and notifies the invalidated FDB entry determination circuit 4025 of the isolated ring ID (step S41). The invalidation FDB entry determination circuit 4025 refers to the packet ring information table of the own node (FIG. 4A) and confirms that the isolated ring ID (# 3) does not match the ring ID of the ring to which the own node belongs. To do. Then, the invalidation FDB entry determination circuit 4025 invalidates, for example, by deleting only the FDB entry with the isolated ring ID = # 3 in the address table of its own node (step S42).

  Next, nodes other than the interlink node 2a and the interlink node 2a in the second ring will be described.

  The interlink node 2a is not an interlink node that can directly detect an interlink failure of the interlink 5011, but performs the invalidation process shown in FIG. The isolated ring notification packet receiving circuit 3024 of the interlink node 2a receives the isolated ring notification packet transmitted from the interlink node 1a via the MAC / PHY circuit 3015, and reads the isolated ring ID = # 3 (step S31). , S32). The isolated ring determination circuit 3020 refers to the packet ring information table of the own node (FIG. 4B) (step S33), and the third ring which is an isolated ring is the bypass path connection destination ring of the ring to which the own node belongs. Make sure that In this case, the invalidated FDB entry determination circuit 3025 invalidates only the FDB entry with the isolated ring ID = # 3 in the address table of the own node by, for example, deleting it.

  Nodes other than the interlink node 2a in the second ring perform the operation shown in FIG. The isolated ring notification packet receiving circuit 4024 receives the isolated ring notification packet transmitted from the interlink node 2a via the control packet processing circuit 3017. Then, the isolated ring notification packet receiving circuit 4024 reads the isolated ring ID = # 3 from the isolated ring notification packet and notifies the invalidated FDB entry determination circuit 4025 of the isolated ring ID (step S41). The invalidation FDB entry determination circuit 4025 refers to the packet ring information table of the own node (FIG. 4B) and confirms that the isolated ring ID (# 3) does not match the ring ID of the ring to which the own node belongs. To do. Then, the invalidation FDB entry determination circuit 4025 invalidates, for example, by deleting only the FDB entry with the isolated ring ID = # 3 in the address table of its own node (step S42).

  As described above, in the packet ring network system as shown in FIG. 11, when a failure occurs in the interlink 5011, in the first ring and the second ring, only entries that have a ring that is an isolated ring as a transmission source. Disable. Further, in the third ring that is an isolated ring, the entry that uses a ring other than the third ring (first and second rings) as a transmission source is deleted. Recognize isolated ring and selectively delete FDB entry for each packet ring in interlink node and nodes other than interlink node to leave usable entry even when using bypass path Can do. Therefore, the occurrence of flooding when an interlink failure occurs can be reduced, and the FDB relearning time when an interlink failure occurs can be shortened.

Embodiment 2. FIG.
In the first embodiment, the ring ID PUSH / POP circuit 3027 may stack (add multiple) the ring ID shim header (step S3 shown in FIG. 6). In a packet ring network composed of a hub ring and a plurality of sub-rings connected directly to the hub ring through an interlink (except for a configuration in which sub-rings are inter-connected in multiple stages in addition to the sub-ring), this is given to client packets. The maximum number of ring ID shim headers to be performed may be one. FIG. 12 is a flowchart showing the operation of the ring ID PUSH / POP circuit 3027 when the maximum number of ring ID shim headers to be added to the client packet is one. FIG. 12A shows the insertion operation of the ring ID shim header, and FIG. 12B shows the deletion operation of the ring ID shim header.

First, the ring ID shim header insertion operation will be described (see FIG. 12A). When the MAC / PHY circuit 3015 receives a client packet from the tributary port, the ring ID PUSH / POP circuit 3027 receives the client packet via the packet conversion circuit 3011 (step S51). When the ring ID PUSH / POP circuit 3027 receives the client packet, the ring ID PUSH / POP circuit 3027 determines whether or not a ring ID (ring ID shim header) is added immediately before the client packet (step S52). Steps S51 and S52 are the same as steps S1 and S2 shown in FIG. When the ring ID is inserted (Y in step S52), the ring ID PUSH / POP circuit 3027 sends the packet ID to the packet conversion circuit 3011 while keeping the ring ID shim header as it is (steps S53 and S55). . If the ring ID is not assigned to the client packet (N in step S52), the ring ID PUSH / POP circuit 3027 uses the “own ring ID” included in the packet ring information table as the ring ID shim header and the payload of the client packet. (Step S54), and the client packet is sent to the packet conversion circuit 3011 (step S55).
.

  Next, the ring ID shim header deletion operation will be described (see FIG. 12B). The ring ID PUSH / POP circuit 3027 receives the decapsulated client packet from the packet conversion circuit 3011 (step S61). If the own node is not an interlink node (N in step S62), the ring ID PUSH / POP circuit 3027 deletes all ring ID shim headers inserted in the client packet (step S63), and proceeds to step S65. When the own node is an interlink node (Y in step S62), the process proceeds to step S65 while keeping the ring ID shim header as it is (step S64). In step S65, the ring ID PUSH / POP circuit 3027 outputs the client packet to the packet conversion circuit 3011, and the packet conversion circuit 3011 transmits the client packet from the tributary port via the MAC / PHY circuit 3015.

  The process shown in FIG. 12 is obtained by removing the stack PUSH process of the ring ID shim header and the determination branch related to the number of stacks from the process shown in FIG. In this case, since there is always only one ring ID shim header given to the client packet in the packet ring, there is an effect that the band use efficiency is improved.

  The other points are the same as in the first embodiment.

  FIG. 13 is an explanatory diagram illustrating an example of FDB learning in the second embodiment. Hereinafter, an example of insertion and deletion of a ring ID shim header in the present embodiment will be described with reference to FIG. The client terminal A transmits the client packet addressed to the client terminal B to the basic node 3c in the third ring using the self-confidence address “A” as the transmission source. Here, the case where the basic node 3c broadcasts a client packet is taken as an example. However, the same applies when unicast transmission or Unknown unicast packet is transmitted. Since the ring ID shim header is not added to the received client packet, the basic node 3c adds a shim header indicating its own node's ring ID = # 3 immediately before the payload (step S54). 3c transmits an RPR packet to each node in the third ring. This RPR packet reaches the interlink node 3a.

  The interlink node 3a decapsulates the received RPR packet and extracts a client packet. The interlink node 3a transmits the client packet to the interlink 1b in the first ring without changing the attached ring ID shim header (step S64).

  Since the ring ID shim header (# 3) is added to the client packet received by the interlink 1b from the interlink node 3a (Y in step S52), the interlink 1b encapsulates the client packet as it is and performs RPR. Send the packet to each node in the first ring. This RPR packet reaches the interlink node 1a.

  The interlink node 1a decapsulates the received RPR packet and extracts a client packet. The interlink node 1a transmits the client packet to the interlink 2a in the second ring without changing the attached ring ID shim header (step S64).

  Since the ring ID shim header (# 3) is added to the client packet received by the interlink 2a from the interlink node 1a (Y in step S52), the interlink 2a encapsulates the client packet as it is and performs RPR. Send the packet to each node in the second ring. This RPR packet reaches the basic node 2c.

  The basic node 2c decapsulates the received RPR packet and extracts a client packet. Since the basic node 2c is not an interlink node (N in step S62), all ring ID shim headers (# 3 in this case) attached to the client packet are deleted. Further, the basic node 2c receives the RPR MAC SA (source address, here 2a) of the received RPR packet, the MAC SA (source address, here A) of the client packet stored in the RPR packet, and the client The ring ID (# 3 in this case) assigned to the packet is associated with and stored in the address table storage unit 3010.

Next, a modification of the embodiment of the present invention will be described.
In the first and second embodiments, the packet ring network system in which two rings are hub-connected to the first ring has been described. A configuration in which three or more rings are hub-connected to the first ring may be employed. That is, a configuration in which three or more rings including a bypass route node are connected to one ring may be employed. All the sub-rings are directly interlinked to the first ring, and a bypass path is formed between any two sub-rings.

  The configuration and operation of each interlink node, each bypass route node, and each basic node are the same as the configuration and operation described in the first embodiment. The operation described in the second embodiment may be the same.

  FIG. 14 shows an example of a packet ring network system in which four sub rings from the second ring to the fifth ring are connected to the first ring. The first ring includes interlink nodes 1a to 1d and basic nodes 1e to 1g. The second ring includes an interlink node 6a, a bypass route node 6d, and basic nodes 6b and 6c. The third ring includes an interlink node 3a, a bypass route node 3d, and basic nodes 3b and 3c. The fourth ring includes an interlink node 4a, a bypass path node 4f, and basic nodes 4b to 4e. The fifth ring includes an interlink node 5a, a bypass route node 5f, and basic nodes 5b to 5e.

  The interlink nodes 1a and 6a are connected via an interlink 8004, and the interlink nodes 1b and 5a are connected via an interlink 8006. The bypass path nodes 6d and 5f are connected via a bypass path 8001. When a failure occurs in any of the interlinks 8004 and 8006, the bypass path node 8001 is linked up. That is, it begins to be used as a transfer path for client packets. The interlink nodes 1c and 4a are connected via an interlink 8005, and the interlink nodes 1d and 3a are connected via an interlink 8003. The bypass path nodes 4f and 3d are connected via a bypass path 8002. When a failure occurs in any of the interlinks 8005 and 8003, the bypass path node 8002 is linked up. The operation of each node when a failure occurs in the interlink is the same as in the first embodiment.

  There is no limit to the number of sub-rings connected to the hub ring. When the number of sub-rings is an even number, any two sub-rings are made into one set, and a bypass path is set between the two sub-rings. Should be deployed.

  When the number of sub-rings is an odd number, it is necessary to provide a plurality of bypass route nodes for one or more sub-rings. FIG. 15 is an explanatory diagram showing a configuration example when there are three sub rings. The first ring includes interlink nodes 1a to 1c and basic nodes 1d to 1f. The second ring includes an interlink node 2a, a bypass path node 2d, and basic nodes 2b and 2c. The third ring includes an interlink node 3a, a bypass route node 3b, and basic nodes 3c and 3d. The fourth ring includes an interlink node 4a, bypass path nodes 4b and 4f, and basic nodes 4c to 4e. The interlink nodes 1a and 2a are connected via an interlink 9004. The interlink nodes 1b and 4a are connected via an interlink 9003. The interlink nodes 1c and 3a are connected via an interlink 9005. Further, the bypass route nodes 2 d and 4 f are connected via a bypass route node 9001, and the bypass route nodes 3 b and 4 b are connected via a bypass route node 9002.

  As shown in FIG. 15, when the number of sub-rings is an odd number, a plurality of bypass path nodes are provided in one or more sub-rings (fourth ring in the example shown in FIG. 15), and other sub-rings A plurality of bypass paths are provided between the two. The bypass path 9001 is applied as an alternative path to the interlink failure of the interlink 9004, the bypass path 9002 is applied to the interlink fault of the interlink 9005 as an alternative path, and the bypass path 9001 is applied to the interlink fault of the interlink 9003. Either one of 9002 and 9002 is applied as an alternative route. In this case, the interlink node in the ring in which a plurality of bypass path nodes are provided (in the example shown in FIG. 15, the interlink node 4a of the fourth ring) is shown in the first embodiment in the following points. Different from the interlink node. The configuration and operation of other nodes (each node other than the interlink node 4a) are the same as those in the first embodiment or the second embodiment.

  The packet ring information table stored in the packet ring information table storage unit 3021 of the interlink node 4a includes a plurality of bypass path connection destination ring IDs. That is, it is necessary to set a plurality of bypass path connection destination ring IDs corresponding to the plurality of bypass path nodes 4f and 4b as entries. Other configurations and operations are the same as those in the first embodiment or the second embodiment.

Embodiment 3. FIG.
In the first embodiment and the second embodiment, the case has been described in which there is no lower-layer subring in which the subring is a hub ring. The sub-ring may be a hub ring, and the sub-ring may be further connected to the lower layer of the sub-ring. In this case, the configuration of the interlink nodes and the nodes other than the interlink nodes is the same as that of the first embodiment (see FIGS. 2 and 5). However, the ring ID shim header insertion and deletion operations by the ring ID PUSH / POP circuit 3027 are different from those of the first embodiment. Further, when a plurality of ring IDs are assigned to the client packet, the operation for specifying the ring ID to be learned in the address table is different from that in the first embodiment. Other operations are the same as those in the first embodiment.

  FIG. 16 is an explanatory diagram illustrating a configuration example in which a sub-ring is further connected to the sub-ring. In the example shown in FIG. 16, the second ring and the third ring are connected as sub-rings to the first ring. A fourth ring and a fifth ring are further connected as sub-rings to the second ring. Similarly, a sixth ring and a seventh ring are further connected as sub-rings to the third ring. If the sub-rings that are connected via the bypass path and are paired are directly connected to the same hub ring, the number of rings and the number of connection stages of the sub-rings are not limited.

  In the example illustrated in FIG. 16, the first ring includes interlink nodes 1a and 1b and basic nodes 1d to 1f. The second ring includes interlink nodes 2a, 2c, 2d, a bypass path node 2e, and a basic node 2b. The third ring includes interlink nodes 3a, 3c, 3d, a bypass route node 3e, and a basic node 3b. The interlink nodes 1a and 2a are connected via an interlink. Similarly, the interlink nodes 1b and 3a are connected via an interlink. Further, the bypass path nodes 2e and 3e are connected via a bypass path. The fourth ring includes an interlink node 2a ', a bypass path node 2e', and basic nodes 2b 'to 2d'. The fifth ring includes an interlink node 2a ", a bypass path node 2b", and basic nodes 2c "to 2e". The interlink nodes 2c and 2a 'are connected via an interlink. Similarly, the interlink nodes 2d and 2a '' are connected via an interlink. Further, the bypass route nodes 2e 'and 2b "are connected via the bypass route. The sixth ring includes an interlink node 3a '', a bypass path node 3b '', and basic nodes 3c '' to 3e ''. The seventh ring includes an interlink node 3a ', a bypass path node 3e', and basic nodes 3b 'to 3d'. The interlink nodes 3d and 3a '' are connected via an interlink. Similarly, the interlink nodes 3c and 3a 'are connected via an interlink. Further, the bypass route nodes 3e 'and 3b "are connected via the bypass route.

  When an interlink failure occurs in the interlink 0001 shown in FIG. 16, the bypass path node 0002 is linked up. That is, it begins to be used as a transfer path for client packets. At this time, only the second, fourth, and fifth rings cause flooding of the RPR network due to the address table invalidation, and the other rings are not affected.

  FIG. 17 is a flowchart showing the operation of the ring ID PUSH / POP circuit 3027 of each node in the third embodiment. FIG. 17A shows a ring ID shim header insertion operation, and FIG. 17B shows a ring ID shim header deletion operation. For operations similar to those in FIG. 6, step numbers similar to those in FIG. 6 are given.

  First, the ring ID shim header insertion operation in this embodiment will be described. However, the operation up to step S2 and the operation after step S4 are the same as those in the first embodiment, and a description thereof will be omitted. If it is determined in step S2 that a ring ID has been inserted (Y in step S2), the node is an interlink node. In this case, the ring ID PUSH / POP circuit 3027 refers to the packet ring information table of the own node, and the connection destination ring to which the own node (own interlink node) is connected is an upper layer ring or a lower layer ring. It is determined whether or not there is (step S71). Ring ID PUSH / POP circuit 3027 refers to the packet ring information table, and if the ring ID of the connection destination ring corresponding to the address of the own node is stored as “upper layer ring ID”, the connection destination ring is higher. If it is determined as a layer ring and stored as “lower layer ring ID”, it is determined that the connection destination ring is a lower layer ring.

  When the connection destination ring is an upper layer ring, the ring ID PUSH / POP circuit 3027 inserts its own ring ID on the side opposite to the payload of the already inserted ring ID shim header (step S73). In the first embodiment, ring ID shim headers to be added later are sequentially added immediately before the payload, but in step S73 of the third embodiment, the payload of the ring ID shim header that has already been inserted Inserts its own ring ID on the opposite side (that is, before the ring ID shim header already inserted just before the payload). The own ring ID may be extracted from the packet ring information table.

  After step S73, the ring ID PUSH / POP circuit 3027 assigns a learning ring ID identifier to a predetermined position of the client packet (step S74). The learning ring ID identifier should learn which ring ID shim of the two ring IDs assigned to the client packet together with RPR MAC SA (source address of RPR packet) and MAC SA (source of client packet). This is information that indicates whether or not. In step S74, a learning ring ID identifier (hereinafter referred to as “U”) indicating that the ring ID closer to the payload among the two ring IDs assigned to the client should be learned is referred to as a client packet. To grant. For example, the ring ID PUSH / POP circuit 3027 inserts a learning ring ID identifier between the MAC SA of the client packet and the ring ID shim header that has already been assigned.

  When the connection destination ring is an upper layer ring, the ring ID PUSH / POP circuit 3027 inserts its own ring ID between the already inserted ring ID shim header and the payload (that is, immediately before the payload) ( Step S76). The own ring ID may be extracted from the packet ring information table.

  After step S76, the ring ID PUSH / POP circuit 3027 assigns a learning ring ID identifier to a predetermined position of the client packet (step S77). In step S77, the ring ID PUSH / POP circuit 3027 learns a ring ID identifier (hereinafter referred to as “ring ID”) that indicates that one of the two ring IDs assigned to the client that is not close to the payload should be learned. (Denoted as “D”). As described above, the position where the learning ring ID identifier is inserted is, for example, between the MAC SA of the client packet and the ring ID shim header already assigned.

  After steps S4, S74, and S77, the ring ID PUSH / POP circuit 3027 sends the client packet to the packet conversion circuit 3011 (step S5). In step S4, the learning ring ID identifier is not inserted.

  Next, the operation of deleting the ring ID shim header in this embodiment will be described. However, the operations from step S11 to step S12 and the operation of step S14 are the same as those in the first embodiment, and the description thereof will be omitted. If it is determined in step S12 that the own node is not an interlink node, the ring ID PUSH / POP circuit 3027 deletes all ring ID shim headers inserted in the client packet (step S13), and proceeds to step S18. . However, in this embodiment, when the learning ring ID identifier is assigned, the ring ID PUSH / POP circuit 3027 also deletes the learning ring ID identifier together with the ring ID shim header in step S13. After step S13, the process proceeds to step S18 as in the first embodiment.

  If the number of ring ID shim headers determined in step S14 is one, the process proceeds to step S18 as in the first embodiment.

  When the number of ring ID shim headers determined in step S14 is two, the ring ID PUSH / POP circuit 3027 refers to the packet ring information table and is connected to the own node (own interlink node). It is determined whether the ring is an upper layer ring or a lower layer ring (step S15). The operation in step S15 is the same as that in step S71 (see FIG. 17A).

  When the connection destination ring is an upper layer ring, the ring ID PUSH / POP circuit 3027 holds one ring ID close to the payload and deletes the other ring ID (step S16). That is, of the two ring IDs, the ring ID that is not close to the payload is deleted.

  When the connection destination ring is a lower layer ring, the ring ID PUSH / POP circuit 3027 deletes one ring ID on the side close to the payload and deletes the other ring ID when the connection destination ring is a lower layer ring. Is held as it is (step S17).

  The ring ID PUSH / POP circuit 3027 also deletes the learning ring ID identifier in steps S16 and S17.

  After steps S16 and S17, the process proceeds to step S18. The operation in step S18 is the same as that in the first embodiment. Deleting the ring ID as in steps S16 and S17 means that the ring belonging to the combination of the hub ring and the sub ring including the ring to which the own node belongs (own ring) and the ring connected to the own node via the interlink. This means that a ring ID other than the ring ID of the ring that first transmitted the client packet to another ring is deleted.

  Next, in the third embodiment, an operation of specifying a ring ID that each node (interlink node, basic node, and bypass route node) should learn from the address table will be described. FIG. 18 is a flowchart of an operation in which each of these nodes performs FDB learning in the third embodiment.

  When the multiplexing circuit 3005 receives an RPR packet to be copied or stripped from the forwarding circuit, the multiplexing circuit 3005 outputs the RPR packet to the packet conversion circuit 3011 (step S81). The RPR packet is input from the multiplexing circuit 3005 to the packet conversion circuit 3011. The packet conversion circuit 3011 decapsulates the client packet from the RPR packet, and determines whether or not a learning ring ID identifier is given to the client packet (step S82).

  When the learning ring ID identifier is not assigned, the packet conversion circuit 3011 associates the RPR MAC SA of the RPR packet, the MAC SA of the client packet, and the ring ID of the own ring and stores them in the address table storage unit 3010. (Step S84).

  When the learning ring ID identifier is assigned, the packet conversion circuit 3011 determines whether the learning ring ID identifier is “U” or “D” (step S85).

  When the learning ring ID identifier is “U”, the packet conversion circuit 3011 associates the RPR MAC SA of the RPR packet, the MAC SA of the client packet, and the ring ID added to the payload side of the client packet. Then, it is stored in the address table storage unit 3010 (step S86).

  When the learning ring ID identifier is “D”, the packet conversion circuit 3011 approaches the payload of the RPR MAC SA of the RPR packet, the MAC SA of the client packet, and the two ring IDs inserted in the client packet. The other ring ID (ring ID inserted on the learning ring ID identifier side) is associated and stored in the address table storage unit 3010 (step S87).

  In steps S86 and S87, the ring ID that is not the own ring ID among the two ring IDs assigned to the client packet is determined as the ring ID stored in the address table storage unit 3010.

  In the above FDB learning, among the rings belonging to the combination of the hub ring and the sub-ring including the own ring and the ring that transmitted the client packet to the own ring via the interlink, The ID of the ring transmitted to the ring is registered.

  Hereinafter, an example of the FDB learning operation in the case where a sub ring is further provided below the sub ring will be described. FIG. 19 is an explanatory diagram illustrating an example of FDB learning when a sub ring is further provided in a lower layer of the sub ring. In the packet ring network system shown in FIG. 19, a client packet of DA = FF and SA = A is transmitted from the client apparatus A connected to the tributary port of the node 3c ′ of the seventh ring, and the fourth ring A packet transfer process until a client packet is received by the client apparatus B connected to the tributary port of the node 2c ′ will be described as an example. The node 2c ′ of the fourth ring learns the SA of the RPR packet (RPR MAC SA), the SA of the client packet (MAC SA), and the client packet transmission source ring ID in the address table in its own node, and constructs the table. The operation up to is as follows.

  When the basic node 3c ′ receives the client packet from the client device A, the ring ID PUSH / POP circuit 3027 of the basic node 3c ′ performs the PUSH operation of the ring ID shim header by the operation shown in FIG. Since the basic node receives the client packet from the client device at the tributary port, the ring ID shim header is not already added to the received client packet. Therefore, the ring ID PUSH / POP circuit 3027 refers to its own ring ID in the packet ring information table, and inserts the ring ID = # 31 immediately before the payload of the client packet (see step S4, FIG. 17A). .) A client packet to which one ring ID shim header is attached is generated and output to the packet conversion circuit 3011 (step S5).

  Here, a case where the client packet received from the client apparatus A is encapsulated and broadcast is described as an example. The basic node 3c ′ performs flooding by encapsulating the client packet to which the ring ID = # 3 is assigned by RPR packet transmission using a normal RPR packet transmission process. This RPR packet reaches the interlink node 3a '. The interlink node 3a 'copies the received RPR packet, decapsulates it by normal RPR packet reception processing, and outputs the client packet to which the ring ID = # 31 is assigned from the tributary port. At this time, the ring ID PUSH / POP circuit 3027 of the interlink node 3a ′ performs the operation shown in FIG. Here, since the ring ID assigned to the client packet is one, the ring ID is sent as it is to the tributary port without performing PUSH / POP (shift from step S14 to step S18). The tributary port of the interlink node 3c receives this client packet via the interlink.

  The ring ID PUSH / POP circuit 3027 of the interlink node 3c pushes the ring ID shim header by the operation shown in FIG. In this example, since the ring ID shim header (# 31) is already added to the client packet input from the tributary port (interlink) (Y in step S2), the ring ID PUSH / POP circuit 3027 Referring to the information table, it is determined whether the connection destination ring to which the node is connected is an upper layer ring or a lower layer ring (step S71). In this example, since the connection destination of the own node (interlink node 3c) is a lower layer ring, the ring ID shim header of the own ring ID = # 3 is placed between the already provided ring ID shim header and the payload. PUSH is performed (step S76). Further, the ring ID PUSH / POP circuit 3027 gives the learning ring ID identifier “D” to the client packet (step S77). That is, a client packet to which two ring ID shim headers # 3 and # 31 and “D” are assigned is generated and output to the packet conversion circuit 3011.

  The interlink node 3c performs RPR encapsulation on the client packet to which the ring ID = # 31 and # 3 are assigned by RPR packet transmission processing and floods the packet. This RPR packet reaches the interlink node 3a. The interlink node 3a copies the received RPR packet, decapsulates it by normal RPR packet reception processing, and outputs the client packet from the tributary port. At this time, the ring ID PUSH / POP circuit 3027 of the interlink node 3a deletes the ring ID by the operation shown in FIG. Here, since there are two ring IDs assigned to the client packet, the ring ID PUSH / POP circuit 3027 of the interlink node 3a refers to the packet ring information table of the own node and determines the connection destination ring of the own node. It is determined whether the ring is an upper layer ring or a lower layer ring (step S15). Since the connection destination ring of the own interlink node 3a is an upper layer ring (that is, because the first ring is a hub ring for the third ring), one of the rings close to the payload of the client packet The ID shim header (# 3) is held, the other ring ID shim header (# 31) and the learning ring ID identifier are POP, and then sent to the tributary port (steps S16 and S18). The tributary port of the interlink node 1b receives this client packet.

  Since one ring ID shim header (# 3) is given to this client packet (Y in step S2), the ring ID PUSH / POP circuit 3027 of the interlink node 1b refers to the packet ring information table. It is determined whether the connection destination ring to which the node is connected is an upper layer ring or a lower layer ring (step S71). Here, the connection destination of the own node (interlink node 1b) is a lower layer ring. Accordingly, the ring ID PUSH / POP circuit 3027 inserts its own ring ID between the already inserted ring ID shim header and the payload (step S76). Further, the ring ID PUSH / POP circuit 3027 gives the learning ring ID identifier “D” to the client packet (step S77). The interlink node 1b performs flooding by ring-encapsulating the client packet to which the ring ID = # 3 and # 1 and “D” are assigned by normal RPR packet transmission processing. This RPR packet reaches the interlink node 1a. The interlink node 1a copies the received RPR packet, decapsulates it by normal RPR packet reception processing, and outputs the client packet from the tributary port. At this time, the ring ID PUSH / POP circuit 3027 of the interlink node 1a deletes the ring ID by the operation shown in FIG. Here, since there are two ring IDs assigned to the client packet, the ring ID PUSH / POP circuit 3027 of the interlink node 1a refers to the packet ring information table of the own node and determines the connection destination ring of the own node. It is determined whether the ring is an upper layer ring or a lower layer ring (step S15). Since the connection destination of the interlink node 1a is a lower layer ring (that is, because the first ring is a hub ring and the second ring is a sub-ring), one ring ID close to the payload = P1 is POP, and the other ring ID (# 3) is held (step S17). At this time, the learning ring ID identifier is also deleted. Then, the interlink node 1a sends the client packet to the tributary port (step S18). The tributary port of the interlink node 2a receives this client packet via the interlink.

  The ring ID PUSH / POP circuit 3027 of the interlink node 2a inserts a ring ID shim header by the operation shown in FIG. In this example, since the shim header of ring ID = # 3 has already been added to the client packet received from the tributary port (interlink) (Y in step S2), the ring ID PUSH / POP circuit 3027 of the interlink node 2a. Refers to the packet ring information table to determine whether the connection destination ring to which the node is connected is an upper layer ring or a lower layer ring (step S71). Here, the connection destination of the own node (interlink node 2a) is an upper layer ring. Therefore, the ring ID PUSH / POP circuit 3027 inserts its own ring ID (# 2) on the opposite side to the payload of the already inserted ring ID shim header (step S73). In addition, the ring ID PUSH / POP circuit 3027 gives the learning ring ID identifier “U” to the client packet (step S74). The interlink node 2a performs RPR encapsulation on the client packet to which the two ring IDs (# 2, # 3) and “U” are assigned, and floods the packet. This RPR packet reaches the interlink node 2c.

  The ring ID PUSH / POP circuit 3027 of the interlink node 2c deletes the ring ID by the operation shown in FIG. Here, since there are two ring IDs assigned to the client packet, the ring ID PUSH / POP circuit 3027 of the interlink node 2c refers to the packet ring information table of the own node and determines the connection destination ring of the own node. It is determined whether the ring is an upper layer ring or a lower layer ring (step S15). Since the connection destination ring of the own node (interlink node 2c) is a lower layer ring, the ring ID PUSH / POP circuit 3027 deletes the ring ID (# 3) on the payload side and is not close to the payload The ring ID (# 2) is held (step S17). At this time, the learning ring ID identifier is also deleted. The interlink node 2c transmits this client packet to the interlink node 2a 'in the fourth ring via the interlink.

  The ring ID PUSH / POP circuit 3027 of the interlink node 2a ′ inserts a ring ID shim header by the operation shown in FIG. In this example, a ring ID (# 2) is assigned to the received client packet (Y in step S2). Therefore, the ring ID PUSH / POP circuit 3027 of the interlink node 2a ′ refers to the packet ring information table to determine whether the connection destination ring to which the node is connected is an upper layer ring or a lower layer ring. Determination is made (step S71). Since the connection destination ring of the own node (interlink node 2a ′) is an upper layer ring, the ring ID PUSH / POP circuit 3027 is self-ringed on the side opposite to the payload of the already assigned ring ID (# 2). An ID (# 21) is assigned (step S73). Further, the ring ID PUSH / POP circuit 3027 assigns a learning ring identifier “U”. The interlink node 2a 'encapsulates and floods this client packet.

  The flooded RPR packet reaches the basic node 2c '. The basic node 2c 'decapsulates the RPR packet by a normal RPR packet reception process. Further, FDB learning is performed by the process shown in FIG. When receiving the RPR packet, the packet conversion circuit 3011 of the basic node 2c ′ determines whether or not a learning ring ID identifier is assigned, and if so, the type (“U” or “D”). ) Is determined (step S82). In this example, since the ring ID “U” is assigned, the packet conversion circuit 3011 of the basic node 2c ′ uses the RPR MAC SA of the received RPR packet, the MAC SA of the decapsulated client packet, and the payload. The ring ID (# 2) inserted in close proximity is associated with and stored in the address table storage unit 3010.

  Further, the ring ID PUSH / POP circuit 3027 of the basic node 2c ′ deletes the ring ID by the operation shown in FIG. The ring ID PUSH / POP circuit 3027 of the basic node 2c ′ performs the process of step S13 because the node is not an interlink node. That is, all ring ID shim headers attached to the client packet are deleted. In this embodiment, the learning ring ID identifier is also deleted in step S13. The basic node 2 c ′ transmits the client packet to the client device B.

  With the above operation, for the client packet transmitted from the client device A and the basic node 3c ′ and received by the client device B and the basic node 2c ′, the source address (RPR MAC) of the RPR packet is received at the receiving basic node 2c ′. SA), client packet source address (MAC SA), and client packet source ring ID = # 2.

  For the basic node of the fourth ring, the source ring of the client packet is the second ring that is interlink-connected or the fifth ring that is connected to the bypass path (not shown in FIG. 15). In the above operation example, the source ring ID is not the seventh ring ID (# 31).

  In the above description, the basic node 2c ′ is taken as an example, and the case where the source address of the RPR packet, the source address of the client packet, and the ring ID are associated with each other and stored in the address table storage unit 3010 is taken as an example. Each node in each packet ring also performs FDB learning by the process shown in FIG. For example, the basic node 3d illustrated in FIG. 19 receives an RPR packet that stores a client packet to which two ring IDs (# 31, # 3) and a learning ring ID identifier “D” are assigned. In this case, since the learning ring ID identifier “D” is given, the processing is performed in the order of steps S81, S82, S85, and S87, and the packet conversion circuit 3011 of the basic node 3d determines the source address of the RPR packet, the client The packet transmission source address and the ring ID (# 31) that is not close to the payload of the two ring IDs are associated with each other and stored in the address table storage unit 3010.

  In the above example, each node in the seventh ring receives the RPR packet storing the client packet to which the learning ring ID identifier is not assigned. Therefore, processing is performed in the order of steps S81, S82, and S84, and the source address of the RPR packet, the client packet source address, and the own ring ID are associated and stored in the address table storage unit 3010.

  In the above description, the broadcast transfer is described as an example for the RRP packet and the client packet, but the operation of learning the transmission source of the RPR packet, the transmission source of the client packet, and the ring ID by unicast transfer is the same. The operation when learning is performed by receiving an Unknown unicast packet is the same.

  In the third embodiment, the learning ring ID identifier is assigned to the client packet. This is because, in steps S86 and S87, the ring ID that is not the self ring ID of the two ring IDs assigned to the client packet is determined as the ring ID stored in the address table storage unit 3010. is there. In the third embodiment, the packet conversion circuit 3011 refers to the own ring ID in the packet ring information table, and the ring that does not match the own ring ID of the two ring IDs assigned to the client packet. The ID may be stored in the address table storage unit 3010 in association with the RPR MAC SA and MAC SA. In this case, since the ring ID to be learned is determined with reference to the self-ring ID stored in advance, the learning ring ID identifier need not be assigned. That is, steps S74 and S77 (see FIG. 14A) need not be performed.

  Also in the third embodiment, the sub-ring may be connected to the ring serving as the hub ring in the manner illustrated in FIGS. 14 and 15.

  In the third embodiment, as illustrated in FIG. 19, a certain sub-ring (second ring or third ring) serves as a hub ring, and further sub-rings (fourth to seventh rings) with respect to the hub ring. The ring is connected as an example. The operation of the third embodiment is also applicable to a configuration in which a sub-ring is connected to a hub ring and the sub-ring is not a hub ring of another ring, as shown in FIG.

  In each of the above embodiments, the various nodes of the present invention have been described as configurations including various processing units such as the RPR basic node unit 3019. The interlink node is realized by a computer including a storage device, and the RPR basic node unit 3019, the isolated ring determination circuit 3020, and the isolated ring notification packet generation circuit 3022 according to the interlink node program stored in the storage device. The isolated ring notification packet transmission circuit 3023, the isolated ring notification packet reception circuit 3024, the invalidation FDB entry determination circuit 3025, the interlink failure detection circuit 3026, and the ring ID PUSH / POP circuit 3027 may be configured to operate. . .

  Similarly, nodes other than the interlink (basic node and bypass path load) are realized by a computer having a storage device, and the RPR basic node unit 3019, the isolated ring is executed according to the node program stored in the storage device by the computer. The notification packet receiving circuit 4024, the invalidation FDB entry determination circuit 4025, and the ring ID PUSH / POP circuit 3027 may be configured to operate.

  Next, the outline of the present invention will be described. FIG. 20 is an explanatory diagram showing the outline of the present invention (particularly, the outline of the node configuration). The packet ring network system of the present invention has a plurality of packet ring networks in which nodes are connected in a ring shape, and transmits and receives in-ring packets encapsulating client packets transmitted from terminals outside the packet ring network within the packet ring network. To do.

  The packet ring network system is connected to a plurality of packet ring networks via an interlink which is a packet transfer path used for client packet transfer between the packet ring networks, and at least one set of the plurality of packet ring networks includes: It has a hub ring (for example, the first ring illustrated in FIG. 1) connected via a bypass path that is a packet transfer path used for client packet transfer when an interlink failure occurs.

  The packet ring network system is a packet ring network connected to a hub ring via an interlink, and is connected to another packet ring network connected to the hub ring via an interlink via a bypass path. It has a plurality of sub-rings that are packet ring networks. For example, the example shown in FIG. 1 has a second ring and a third ring.

  The hub ring and each sub-ring include an interlink node that is a node connected to the interlink.

  As shown in FIG. 20, each node 4030 and 3030 in each packet ring network includes a packet ring information table storage unit 91, an address table storage unit 92, a self ring ID insertion unit 93, and a learning unit 95. . Among the nodes, the interlink node 303 includes a ring ID deletion unit 94.

  The packet ring information table storage unit 91 includes an own ring ID that is an ID of a packet ring network to which the own node belongs, an address of an interlink node in the packet ring to which the own node belongs, and a packet ring connected to the interlink node. Including a connection destination ring ID, which is a network ID, and information indicating whether a packet ring network connected to the interlink node corresponds to a sub-ring or a hub ring when viewed from the own node. When a packet ring network is connected to another packet ring network via a bypass route, a packet ring information table that is information further including a bypass route connection destination ring ID that is an ID of the other packet ring network is stored.

  The address table storage unit 92 stores a forwarding database in which addresses of nodes in the packet ring network, terminal addresses, and packet ring network IDs are associated with each other.

  When the own node receives the client packet, the own ring ID inserting unit 93 inserts the own ring ID into the client packet.

  The learning means 95, when receiving an intra-ring packet encapsulating a client packet, a packet ring network to which the own node belongs and a packet ring network that transmits the client packet to the packet ring network via an interlink The ring ID of the packet ring network that first transmitted the client packet to another packet ring network in the packet ring network that belongs to the combination of the hub ring and sub ring including the packet, the source address of the packet in the ring, and the client The packet source address is associated and stored in the address table storage means.

  The ring ID deletion means 94 of the interlink node is inserted into the client packet when the client packet decapsulated from the packet in the ring received from the node in the packet ring network to which the own node belongs is transmitted via the interlink. First, the client packet in a packet ring network belonging to a combination of a hub ring and a sub-ring including a packet ring network to which the own node belongs and a packet ring network connected to the own node via the interlink. The ring ID other than the ring ID of the packet ring network that has transmitted to the other packet ring network is deleted.

  With the above configuration, the forwarding database entry can be managed together with the ring ID. As a result, the entry of the forwarding database can be deleted for each ring ID (for each packet ring network). That is, when an interlink failure occurs, it is not necessary to delete the entire forwarding database, and it is possible to specify a ring ID and delete only the entry corresponding to the ring ID. Therefore, the amount of relearning of the forwarding database is reduced, the occurrence of flooding when an interlink failure occurs can be reduced, and the FDB relearning time when an interlink failure occurs can be shortened.

  In the embodiment of the present invention, when each interlink node in each packet ring network detects a failure of an interlink to which the node is connected, and when the failure detection unit detects a failure, Referring to the packet ring information table, when the packet ring network connected to the own node through the interlink is a hub ring as seen from the own node, the own node ID is assigned to the hub ring due to the occurrence of an interring fault. If the packet ring network connected to the local node via the interlink is a sub-ring when viewed from the local node, the packet is connected to the local node. Specify the ring ID of the ring network as the isolated ring ID An isolated ring ID determination unit, an isolated ring ID notification unit that broadcasts an isolated ring ID notification packet including an isolated ring ID, and an isolated ring including an isolated ring ID when the isolated ring ID is determined by the isolated ring ID determination unit If the isolated ring ID matches the own ring ID when the ID notification packet is received, the entry corresponding to the ring ID of the hub ring or the bypass path connection destination ring ID is invalidated from the address table storage means, and the isolated ring ID is If it does not match the own ring ID, the interlink node invalidating means for invalidating the entry corresponding to the isolated ring ID from the address table storage means, and each other than the interlink node in each packet ring network Node notifies isolated ring ID If the isolated ring ID matches the own ring ID when the packet is received, the entry corresponding to the ring ID of the hub ring or the bypass path connection destination ring ID is invalidated from the address table storage means, and the isolated ring ID becomes the own ring. A configuration is disclosed that includes invalidating means for invalidating an entry corresponding to an isolated ring ID from the address table storage means if it does not match the ID.

  In the embodiment (first embodiment) of the present invention, the packet ring network includes only one hub ring and a plurality of sub-rings connected to the hub ring, and the ring ID deletion unit of each interlink node is a client. When two ring IDs are inserted in the packet, the ring ID inserted later is deleted, and when only one ring ID is inserted in the client packet, deletion of the ring ID is kept as it is. When the learning means of each node receives an intra-ring packet encapsulating a client packet and two ring IDs are inserted in the client packet, the one that is not the own ring ID of the two ring IDs Ring ID, the source address of the packet in the ring, and the client Associated with the source address of the packet and stored in the address table storage means, when only the own ring ID is inserted in the client packet, the own ring ID, the source address of the packet in the ring, A configuration is disclosed in which the source address of the client packet is associated with and stored in the address table storage means.

  In the embodiment (second embodiment) of the present invention, the packet ring network includes only one hub ring and a plurality of sub-rings connected to the hub ring. Only when the ring ID is not inserted in the client packet, the own ring ID is inserted in the client packet, and when the learning means of each node receives the packet in the ring encapsulating the client packet, A configuration is disclosed in which a ring ID inserted in the client packet, a transmission source address of the intra-ring packet, and a transmission source address of the client packet are associated and stored in an address table storage unit.

  In the embodiment (third embodiment) of the present invention, if the ring ID is not inserted in the received client packet, the own ring ID insertion unit of each node inserts the own ring ID immediately before the payload. When the ring ID is assigned immediately before the payload of the received client packet, when the packet ring network connected to the own node corresponds to the hub ring when viewed from the own node, immediately before the already inserted ring ID When the packet ring network connected to the own node corresponds to a sub-ring when viewed from the own node, the own ring ID is inserted immediately before the payload, and the ring ID of each interlink node is deleted. When two ring IDs are inserted in the client packet, the means is connected to its own node. When the packet ring network that corresponds to the hub ring is viewed from the local node, the ring ID that is not close to the payload is deleted, and the packet ring network that is connected to the local node corresponds to the sub-ring when viewed from the local node When the ring ID that is closer to the payload is deleted and one ring ID is inserted into the client packet, the ring ID is held as it is, and the learning means of each node When two ring IDs are inserted in the client packet when an intra-ring packet encapsulating the packet is received, the ring ID that is not the own ring ID of the two ring IDs and the intra-ring packet And the source address of the client packet If the self-ring ID is inserted in the client packet, the self-ring ID, the source address of the packet in the ring, the source address of the client packet, Are stored in the address table storage means in association with each other.

  The present invention can be suitably applied to a packet ring network system in which a plurality of sub rings are connected to a hub ring.

It is explanatory drawing which shows the example of the packet ring network system of this invention. It is a block diagram which shows the structural example of an interlink node. It is explanatory drawing which shows the example of an address table. It is explanatory drawing which shows the data structure of a packet ring information table. It is a block diagram which shows the structural example of a basic node. It is a flowchart which shows the example of a process of a ring ID shim header. It is a flowchart which shows the example of a process progress when an interlink node detects an interlink failure. It is a flowchart which shows the example of operation | movement when interlink nodes other than the interlink node which detected the interlink failure receive the isolated ring notification packet. It is a flowchart which shows the example of operation | movement when nodes other than an interlink node receive an isolated ring notification packet. It is explanatory drawing which shows the condition which learns ring ID etc. which are contained in FDB. FIG. 10 is an explanatory diagram showing a change of a packet transfer path when a failure occurs in an interlink 5011. It is a flowchart which shows operation | movement of a ring ID PUSH / POP circuit in case the number of ring ID shim headers provided to a client packet is one at maximum. It is explanatory drawing which shows the example of the FDB learning in 2nd Embodiment. It is explanatory drawing which shows the example of a packet ring network system. It is explanatory drawing which shows the structural example in case there are three sub rings. It is explanatory drawing which shows the structural example which connected the subring further with respect to the subring. It is a flowchart which shows operation | movement of the ring ID PUSH / POP circuit in 3rd Embodiment. It is a flowchart of the operation | movement which each node performs FDB learning in 3rd Embodiment. It is explanatory drawing which shows the example of FDB learning when the sub ring is further provided in the lower layer of the sub ring. It is explanatory drawing which shows the outline | summary of this invention. It is explanatory drawing which shows the network structural example of RPR. It is explanatory drawing which shows a RPR format.

Explanation of symbols

3001, 3002 Forwarding circuit 3003, 3004 Multiplexing circuit 3005 Multiplexing circuit 3006 Ringlet selection circuit 3007 Topology management circuit 3010 Address table storage unit 3011 Packet conversion circuit 3015 MAC / PHY circuit 3019 RPR basic node unit 3020 Isolated ring determination circuit 3021 4021 Packet ring information table storage unit 3022 Isolated ring notification packet generation circuit 3023 Isolated ring notification packet transmission circuit 3024, 4024 Isolated ring notification packet reception circuit 3025, 4025 Invalidation FDB entry determination circuit 3026 Interlink failure detection circuit 3027 Ring ID PUSH / POP circuit

Claims (18)

A packet ring network system in which a node has a plurality of packet ring networks connected in a ring shape, and transmits and receives in-ring packets encapsulating client packets transmitted by terminals outside the packet ring network in the packet ring network,
It is connected to a plurality of packet ring networks through an interlink which is a packet transfer path used for client packet transfer between packet ring networks, and at least one of the plurality of packet ring networks transmits a client packet when an interlink failure occurs. Having a hub ring that is connected via a bypass path, which is a packet transfer path used in
A sub-ring which is a packet ring network connected to a hub ring via an interlink and is connected to another packet ring network connected to the hub ring via an interlink via a bypass path. Have multiple
The hub ring and each sub-ring includes an interlink node that is a node connected to the interlink,
Each node in each packet ring network
The own ring ID that is the ID of the packet ring network to which the own node belongs, the address of the interlink node in the packet ring to which the own node belongs, and the connection destination ring ID that is the ID of the packet ring network connected to the interlink node And information indicating whether the packet ring network connected to the interlink node corresponds to a sub-ring or a hub ring when viewed from the own node, and the packet ring network to which the own node belongs passes through a bypass path A packet ring information table storage means for storing a packet ring information table which is information further including a bypass path connection destination ring ID which is an ID of the other packet ring network when connected to another packet ring network;
Address table storage means for storing a forwarding database in which addresses of nodes in a packet ring network, addresses of terminals, and IDs of packet ring networks are associated with each other;
A self-ring ID inserting means for inserting a self-ring ID into the client packet when the self-node receives the client packet;
Each interlink node in each packet ring network
When a client packet decapsulated from an in-ring packet received from a node in the packet ring network to which the own node belongs is transmitted via an interlink, the packet to which the own node belongs from the ring ID inserted in the client packet A packet ring in which the client packet is first transmitted to another packet ring network in a packet ring network belonging to a combination of a hub ring and a sub-ring including a ring network and a packet ring network connected to the own node via the interlink. A ring ID deleting means for deleting a ring ID other than the ring ID of the network;
Each node in each packet ring network
When receiving an intra-ring packet encapsulating a client packet, a hub ring and a sub that include a packet ring network to which the node belongs and a packet ring network that transmits the client packet to the packet ring network via an interlink. A ring ID of a packet ring network that first transmits the client packet to another packet ring network in a packet ring network belonging to a combination of rings, a source address of the packet in the ring, and a source address of the client packet And a learning means for associating and storing them in the address table storage means. Each interlink node in each packet ring network
A failure detection means for detecting a failure of an interlink to which the own node is connected;
When the failure detection means detects a failure, the packet ring information table is referred to. When the packet ring network connected to the own node via the interlink is a hub ring as seen from the own node, the own node ID is set. When the ID of the isolated ring that cannot transmit and receive packets via the hub ring and the interlink due to the occurrence of an interring failure, and the packet ring network connected to the own node via the interlink is a sub-ring when viewed from the own node Includes an isolated ring ID determination unit that determines a connection destination ring ID that is an ID of a packet ring network connected to the node as an isolated ring ID;
An isolated ring ID notification means for broadcasting an isolated ring ID notification packet including an isolated ring ID;
When the isolated ring ID is determined by the isolated ring ID determination means or when the isolated ring ID notification packet including the isolated ring ID is received, if the isolated ring ID matches the own ring ID, the hub ring is read from the address table storage means. If the entry corresponding to the ring ID or bypass ring connection destination ring ID is invalidated and the isolated ring ID does not match the own ring ID, the interface corresponding to the isolated ring ID is invalidated from the address table storage means. A link node invalidation means,
Each node other than the interlink node in each packet ring network
When an isolated ring ID notification packet is received, if the isolated ring ID matches the own ring ID, the entry corresponding to the ring ID of the hub ring or the bypass path connection destination ring ID is invalidated from the address table storage means, and the isolated ring The packet ring network system according to claim 1, further comprising invalidating means for invalidating an entry corresponding to the isolated ring ID from the address table storage means if the ID does not match the own ring ID. The packet ring network includes only one hub ring and a plurality of sub-rings connected to the hub ring,
When two ring IDs are inserted in the client packet, the ring ID deleting means of each interlink node deletes the ring ID inserted later, and only one ring ID is inserted in the client packet. If there is, delete the ring ID as it is,
When the learning means of each node receives an intra-ring packet encapsulating a client packet and two ring IDs are inserted in the client packet, the learning means of the two ring IDs that are not the own ring ID When the ring ID, the source address of the packet in the ring, and the source address of the client packet are stored in the address table storage unit in association with each other, and only the own ring ID is inserted in the client packet, The packet ring network system according to claim 1 or 2, wherein the own ring ID, the transmission source address of the packet in the ring, and the transmission source address of the client packet are associated and stored in the address table storage unit. The packet ring network includes only one hub ring and a plurality of sub-rings connected to the hub ring,
The own ring ID insertion means of each node inserts the own ring ID into the client packet only when the ring ID is not inserted into the received client packet,
The learning means of each node, when receiving an intra-ring packet encapsulating a client packet, a ring ID inserted in the client packet, a source address of the intra-ring packet, and a source of the client packet The packet ring network system according to claim 1 or 2, wherein the address is stored in the address table storage unit in association with the address. The self ring ID insertion means of each node is
If the ring ID is not inserted in the received client packet, the ring ID is inserted immediately before the payload,
When a ring ID is assigned immediately before the payload of the received client packet, when the packet ring network connected to the own node corresponds to a hub ring when viewed from the own node, immediately before the already inserted ring ID Insert the own ring ID, and when the packet ring network connected to the own node corresponds to the sub-ring when viewed from the own node, insert the own ring ID immediately before the payload,
The ring ID deletion means for each interlink node is:
When two ring IDs are inserted in the client packet, when the packet ring network connected to the own node corresponds to the hub ring when viewed from the own node, the ring ID that is not close to the payload is deleted. When the packet ring network connected to the own node corresponds to the sub-ring when viewed from the own node, the ring ID closer to the payload is deleted,
If there is one ring ID inserted in the client packet, the ring ID is kept as it is,
When the learning means of each node receives an intra-ring packet encapsulating a client packet and two ring IDs are inserted in the client packet, the learning means of the two ring IDs that are not the own ring ID When the ring ID, the source address of the packet in the ring, and the source address of the client packet are stored in the address table storage unit in association with each other, and only the own ring ID is inserted in the client packet, The packet ring network system according to claim 1 or 2, wherein the own ring ID, the transmission source address of the packet in the ring, and the transmission source address of the client packet are associated and stored in the address table storage unit. A packet ring network system in which a node has a plurality of packet ring networks connected in a ring shape, and transmits and receives in-ring packets encapsulating client packets transmitted by terminals outside the packet ring network in the packet ring network, It is connected to a plurality of packet ring networks through an interlink which is a packet transfer path used for client packet transfer between packet ring networks, and at least one of the plurality of packet ring networks transmits a client packet when an interlink failure occurs. A packet ring network that has a hub ring connected via a bypass path, which is a packet transfer path used in communication, and is connected to the hub ring via an interlink A plurality of sub-rings that are packet ring networks connected via bypass paths to other packet ring networks connected to the hub ring via an interlink, wherein the hub ring and each sub-ring are Each node in each packet ring network includes an own ring ID that is an ID of the packet ring network to which the own node belongs and an interface in the packet ring to which the own node belongs. The link node address, the destination ring ID that is the ID of the packet ring network connected to the interlink node, and whether the packet ring network connected to the interlink node corresponds to a sub-ring when viewed from the own node Applicable to hub ring When the packet ring network to which the own node belongs is connected to another packet ring network via a bypass route, it further includes a bypass route connection destination ring ID that is an ID of the other packet ring network. Packet ring information table storage means for storing a packet ring information table as information, an address table for storing a forwarding database in which a node address in a packet ring network, a terminal address, and a packet ring network ID are associated with each other In a forwarding database management method applied to a packet ring network system comprising a storage means,
Each node in each packet ring network
When the own node receives a client packet, it inserts its own ring ID into the client packet,
Each interlink node in each packet ring network
When a client packet decapsulated from an in-ring packet received from a node in the packet ring network to which the own node belongs is transmitted via an interlink, the packet to which the own node belongs from the ring ID inserted in the client packet A packet ring in which the client packet is first transmitted to another packet ring network in a packet ring network belonging to a combination of a hub ring and a sub-ring including a ring network and a packet ring network connected to the own node via the interlink. Delete ring IDs other than the network ring ID,
Each node in each packet ring network
When receiving an intra-ring packet encapsulating a client packet, a hub ring and a sub that include a packet ring network to which the node belongs and a packet ring network that transmits the client packet to the packet ring network via an interlink. A ring ID of a packet ring network that first transmits the client packet to another packet ring network in a packet ring network belonging to a combination of rings, a source address of the packet in the ring, and a source address of the client packet Is stored in the address table storage means in association with the forwarding database management method. Each interlink node in each packet ring network
When a failure of the interlink to which the local node is connected is detected, the packet ring information table is referenced, and the packet ring network connected to the local node via the interlink is a hub ring when viewed from the local node The node ID is the ID of an isolated ring that cannot transmit / receive packets via the hub ring and interlink due to the occurrence of an interring failure, and the packet ring network connected to the node via the interlink is seen from the node. If it is a sub-ring, a connection ring ID that is an ID of a packet ring network connected to the own node is determined as an isolated ring ID,
Broadcasting an isolated ring ID notification packet including an isolated ring ID,
When an isolated ring ID is determined or an isolated ring ID notification packet including an isolated ring ID is received, if the isolated ring ID matches the own ring ID, the ring ID or bypass path connection of the hub ring from the address table storage means Invalidate the entry corresponding to the destination ring ID, and if the isolated ring ID does not match the own ring ID, invalidate the entry corresponding to the isolated ring ID from the address table storage means;
Each node other than the interlink node in each packet ring network
When an isolated ring ID notification packet is received, if the isolated ring ID matches the own ring ID, the entry corresponding to the ring ID of the hub ring or the bypass path connection destination ring ID is invalidated from the address table storage means, and the isolated ring 7. The forwarding database management method according to claim 6, wherein if the ID does not match the own ring ID, the entry corresponding to the isolated ring ID is invalidated from the address table storage means. Applied to a packet ring network system including only one hub ring and a plurality of sub-rings connected to the hub ring as a packet ring network;
Each interlink node
If two ring IDs are inserted in the client packet, the ring ID that was inserted later is deleted, and if only one ring ID is inserted in the client packet, the deletion of the ring ID is retained as it is Let
Each node
When two ring IDs are inserted in the client packet when a packet in the ring encapsulating the client packet is received, the ring ID that is not the self ring ID of the two ring IDs and the ring ID When the packet source address and the client packet source address are associated with each other and stored in the address table storage means, and only the own ring ID is inserted in the client packet, the own ring ID and the ring The forwarding database management method according to claim 6 or 7, wherein a source address of an inner packet and a source address of the client packet are associated with each other and stored in an address table storage unit. Applied to a packet ring network system including only one hub ring and a plurality of sub-rings connected to the hub ring as a packet ring network;
Each node
Only when the ring ID is not inserted in the received client packet, the own ring ID is inserted in the client packet in the client packet,
When an intra-ring packet encapsulating a client packet is received, an address in which the ring ID inserted in the client packet, the source address of the intra-packet packet, and the source address of the client packet are associated with each other The forwarding database management method according to claim 6 or 7, wherein the forwarding database management method is stored in a table storage means. Each node
If the ring ID is not inserted in the received client packet, the ring ID is inserted immediately before the payload,
When a ring ID is assigned immediately before the payload of the received client packet, when the packet ring network connected to the own node corresponds to a hub ring when viewed from the own node, immediately before the already inserted ring ID Insert the own ring ID, and when the packet ring network connected to the own node corresponds to the sub-ring when viewed from the own node, insert the own ring ID immediately before the payload,
Each interlink node
When two ring IDs are inserted in the client packet, when the packet ring network connected to the own node corresponds to the hub ring when viewed from the own node, the ring ID that is not close to the payload is deleted. When the packet ring network connected to the own node corresponds to the sub-ring when viewed from the own node, the ring ID closer to the payload is deleted,
If there is one ring ID inserted in the client packet, the ring ID is kept as it is,
When each node receives an intra-ring packet encapsulating a client packet and two ring IDs are inserted in the client packet, the ring ID of the two ring IDs that are not its own ring ID and If the source address of the packet in the ring and the source address of the client packet are associated and stored in the address table storage means, and only the own ring ID is inserted in the client packet, the own ring ID The forwarding database management method according to claim 6 or 7, wherein a transmission source address of the intra-ring packet and a transmission source address of the client packet are associated with each other and stored in an address table storage unit. A packet ring network system in which a node has a plurality of packet ring networks connected in a ring shape, and transmits and receives in-ring packets encapsulating client packets transmitted by terminals outside the packet ring network in the packet ring network, It is connected to a plurality of packet ring networks through an interlink which is a packet transfer path used for client packet transfer between packet ring networks, and at least one of the plurality of packet ring networks transmits a client packet when an interlink failure occurs. A packet ring network that has a hub ring connected via a bypass path, which is a packet transfer path used in communication, and is connected to the hub ring via an interlink In a packet ring network system having a plurality of sub-rings that are packet ring networks connected via a bypass path to other packet ring networks connected to the hub ring via the inter link. In the connected interlink node,
The own ring ID that is the ID of the packet ring network to which the own node belongs, the address of the interlink node in the packet ring to which the own node belongs, and the connection destination ring ID that is the ID of the packet ring network connected to the interlink node And information indicating whether the packet ring network connected to the interlink node corresponds to a sub-ring or a hub ring when viewed from the own node, and the packet ring network to which the own node belongs passes through a bypass path A packet ring information table storage means for storing a packet ring information table which is information further including a bypass path connection destination ring ID which is an ID of the other packet ring network when connected to another packet ring network;
Address table storage means for storing a forwarding database in which addresses of nodes in a packet ring network, addresses of terminals, and IDs of packet ring networks are associated with each other;
A self-ring ID insertion means for inserting a self-ring ID into the client packet when the self-node receives the client packet;
When a client packet decapsulated from an in-ring packet received from a node in the packet ring network to which the own node belongs is transmitted via an interlink, the packet to which the own node belongs from the ring ID inserted in the client packet A packet ring in which the client packet is first transmitted to another packet ring network in a packet ring network belonging to a combination of a hub ring and a sub-ring including a ring network and a packet ring network connected to the own node via the interlink. A ring ID deleting means for deleting a ring ID other than the ring ID of the network;
When receiving an intra-ring packet encapsulating a client packet, a hub ring and a sub that include a packet ring network to which the node belongs and a packet ring network that transmits the client packet to the packet ring network via an interlink. A ring ID of a packet ring network that first transmits the client packet to another packet ring network in a packet ring network belonging to a combination of rings, a source address of the packet in the ring, and a source address of the client packet Learning means for storing the information in the address table storage means in association with each other. A failure detection means for detecting a failure of an interlink to which the own node is connected;
When the failure detection means detects a failure, the packet ring information table is referred to. When the packet ring network connected to the own node via the interlink is a hub ring as seen from the own node, the own node ID is set. When the ID of the isolated ring that cannot transmit and receive packets via the hub ring and the interlink due to the occurrence of an interring failure, and the packet ring network connected to the own node via the interlink is a sub-ring when viewed from the own node Includes an isolated ring ID determination unit that determines a connection destination ring ID that is an ID of a packet ring network connected to the node as an isolated ring ID;
An isolated ring ID notification means for broadcasting an isolated ring ID notification packet including an isolated ring ID;
When the isolated ring ID is determined by the isolated ring ID determination means or when the isolated ring ID notification packet including the isolated ring ID is received, if the isolated ring ID matches the own ring ID, the hub ring is read from the address table storage means. If the entry corresponding to the ring ID or bypass ring connection destination ring ID is invalidated and the isolated ring ID does not match the own ring ID, the interface corresponding to the isolated ring ID is invalidated from the address table storage means. The interlink node according to claim 11, further comprising an in-link node invalidation unit. A packet ring network system in which a node has a plurality of packet ring networks connected in a ring shape, and transmits and receives in-ring packets encapsulating client packets transmitted by terminals outside the packet ring network in the packet ring network, It is connected to a plurality of packet ring networks through an interlink which is a packet transfer path used for client packet transfer between packet ring networks, and at least one of the plurality of packet ring networks transmits a client packet when an interlink failure occurs. A packet ring network that has a hub ring connected via a bypass path, which is a packet transfer path used in communication, and is connected to the hub ring via an interlink A node used in a packet ring network system having a plurality of sub-rings that are packet ring networks connected via a bypass path to other packet ring networks connected to a hub ring via an interlink Because
The own ring ID that is the ID of the packet ring network to which the own node belongs, the address of the interlink node in the packet ring to which the own node belongs, and the connection destination ring ID that is the ID of the packet ring network connected to the interlink node And information indicating whether the packet ring network connected to the interlink node corresponds to a sub-ring or a hub ring when viewed from the own node, and the packet ring network to which the own node belongs passes through a bypass path A packet ring information table storage means for storing a packet ring information table which is information further including a bypass path connection destination ring ID which is an ID of the other packet ring network when connected to another packet ring network;
Address table storage means for storing a forwarding database in which addresses of nodes in a packet ring network, addresses of terminals, and IDs of packet ring networks are associated with each other;
A self-ring ID insertion means for inserting a self-ring ID into the client packet when the self-node receives the client packet;
When receiving an intra-ring packet encapsulating a client packet, a hub ring and a sub that include a packet ring network to which the node belongs and a packet ring network that transmits the client packet to the packet ring network via an interlink. A ring ID of a packet ring network that first transmits the client packet to another packet ring network in a packet ring network belonging to a combination of rings, a source address of the packet in the ring, and a source address of the client packet And a learning means for associating and storing them in the address table storage means. If an isolated ring ID notification packet for notifying an ID of an isolated ring that cannot transmit / receive packets through the hub ring and the interlink due to the occurrence of an interring failure is received, if the isolated ring ID matches the own ring ID, the address If the entry corresponding to the ring ID of the hub ring or the bypass path connection ring ID is invalidated from the table storage means and the isolated ring ID does not match the own ring ID, the entry corresponding to the isolated ring ID from the address table storage means The node according to claim 13, further comprising an invalidating unit for invalidating. A packet ring network system in which a node has a plurality of packet ring networks connected in a ring shape, and transmits and receives in-ring packets encapsulating client packets transmitted by terminals outside the packet ring network in the packet ring network, It is connected to a plurality of packet ring networks through an interlink which is a packet transfer path used for client packet transfer between packet ring networks, and at least one of the plurality of packet ring networks transmits a client packet when an interlink failure occurs. A packet ring network that has a hub ring connected via a bypass path, which is a packet transfer path used in communication, and is connected to the hub ring via an interlink In a packet ring network system having a plurality of sub-rings that are packet ring networks connected via a bypass path to other packet ring networks connected to the hub ring via the inter link. In an interlink node program mounted on a computer used as an interlink node to be connected,
The computer includes an own ring ID that is an ID of a packet ring network to which the own node belongs, an address of an interlink node in the packet ring to which the own node belongs, and an ID of a packet ring network connected to the interlink node. Including a connection destination ring ID and information indicating whether the packet ring network connected to the interlink node corresponds to a sub-ring or a hub ring when viewed from the own node, and the packet ring network to which the own node belongs bypasses A packet ring information table storage that stores a packet ring information table that is information further including a bypass route connection destination ring ID that is an ID of the other packet ring network when connected to another packet ring network via a route Includes stage and the address of the node of the packet ring network, and the address of the terminal, an address table storage means for storing a forwarding database associating the ID of the packet ring network,
In the computer,
A self-ring ID insertion process for inserting a self-ring ID into the client packet when the self-node receives the client packet;
When a client packet decapsulated from an in-ring packet received from a node in the packet ring network to which the own node belongs is transmitted via an interlink, the packet to which the own node belongs from the ring ID inserted in the client packet A packet ring in which the client packet is first transmitted to another packet ring network in a packet ring network belonging to a combination of a hub ring and a sub-ring including a ring network and a packet ring network connected to the own node via the interlink. When a ring ID deletion process for deleting a ring ID other than the ring ID of the network and an intra-ring packet encapsulating a client packet are received, the node to which the own node belongs A packet ring network belonging to a combination of a hub ring and a sub-ring including a packet ring network and a packet ring network that has transmitted the client packet through an interlink to the packet ring network. A learning process for storing the ring ID of the packet ring network transmitted to the packet ring network, the source address of the packet in the ring, and the source address of the client packet in association with each other and storing them in the address table storage means Interlink node program. On the computer,
Failure detection processing to detect the failure of the interlink to which the local node is connected,
When a failure is detected in the failure detection process, the packet ring information table is referred to. When the packet ring network connected to the own node via the interlink is a hub ring as seen from the own node, the own node ID is set. When the ID of the isolated ring that cannot transmit and receive packets via the hub ring and the interlink due to the occurrence of an interring failure, and the packet ring network connected to the own node via the interlink is a sub-ring when viewed from the own node Includes an isolated ring ID determination process for determining a connection destination ring ID, which is an ID of a packet ring network connected to the own node, as an isolated ring ID,
When an isolated ring ID notification process including an isolated ring ID is broadcast and when an isolated ring ID is determined in an isolated ring ID determination process or when an isolated ring ID notification packet including an isolated ring ID is received If the isolated ring ID matches the own ring ID, the entry corresponding to the ring ID of the hub ring or the bypass path connection destination ring ID is invalidated from the address table storage means, and the isolated ring ID does not match the own ring ID. If so, the interlink node invalidation processing for invalidating an entry corresponding to the isolated ring ID from the address table storage means is executed. A packet ring network system in which a node has a plurality of packet ring networks connected in a ring shape, and transmits and receives in-ring packets encapsulating client packets transmitted by terminals outside the packet ring network in the packet ring network, It is connected to a plurality of packet ring networks through an interlink which is a packet transfer path used for client packet transfer between packet ring networks, and at least one of the plurality of packet ring networks transmits a client packet when an interlink failure occurs. A packet ring network that has a hub ring connected via a bypass path, which is a packet transfer path used in communication, and is connected to the hub ring via an interlink A node used in a packet ring network system having a plurality of sub-rings that are packet ring networks connected via a bypass path to other packet ring networks connected to a hub ring via an interlink In the node program installed in the computer used as
The computer includes an own ring ID that is an ID of a packet ring network to which the own node belongs, an address of an interlink node in the packet ring to which the own node belongs, and an ID of a packet ring network connected to the interlink node. Including a connection destination ring ID and information indicating whether the packet ring network connected to the interlink node corresponds to a sub-ring or a hub ring when viewed from the own node, and the packet ring network to which the own node belongs bypasses A packet ring information table storage that stores a packet ring information table that is information further including a bypass route connection destination ring ID that is an ID of the other packet ring network when connected to another packet ring network via a route Includes stage and the address of the node of the packet ring network, and the address of the terminal, an address table storage means for storing a forwarding database associating the ID of the packet ring network,
In the computer,
When the own node receives the client packet, the own ring ID insertion process for inserting the own ring ID into the client packet, and the packet ring network to which the own node belongs when the in-ring packet encapsulating the client packet is received A packet ring network belonging to a combination of a hub ring and a sub-ring that includes the packet ring network that has transmitted the client packet via an interlink to the packet ring network. An address table that associates the ring ID of the packet ring network transmitted to the packet, the source address of the packet in the ring, and the source address of the client packet A node program for executing a learning process stored in a storage means. On the computer,
If an isolated ring ID notification packet for notifying an ID of an isolated ring that cannot transmit / receive packets through the hub ring and the interlink due to the occurrence of an interring failure is received, if the isolated ring ID matches the own ring ID, the address If the entry corresponding to the ring ID of the hub ring or the bypass path connection ring ID is invalidated from the table storage means and the isolated ring ID does not match the own ring ID, the entry corresponding to the isolated ring ID from the address table storage means The node program according to claim 17, wherein an invalidation process for invalidating a node is executed.

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