JP2017139619A - Repeating device and repeating system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent occurrence of a loop path in a ring network, in a repeating device and a repeating system.SOLUTION: A VID filter control request section 25 of a management card MC determines to change a ring port Pr[1] from an open state to closed state BK in response to an event based on a ring protocol, and issues a close instruction to a line card LC[1]. In response to the close instruction, the port control section 42 of line card LC[1] controls the ring port Pr[1] to the closed state BK, and after completing that control, issues a close completion notice to the management card MC. The R-APS generating section 26 of the management card MC transmits a R-APS frame to the line card after receiving the close completion notice.SELECTED DRAWING: Figure 15

Description

  The present invention relates to a relay device and a relay system, for example, a relay device and a relay system to which a ring protocol is applied.

  For example, in Patent Document 1, in a chassis-type network relay device, each of a plurality of line cards receives a monitoring frame from two redundant management cards, and selects one of them to select the device. The method of transmitting to the outside is shown. Non-Patent Document 1 includes ITU-TG. A ring protocol for a ring network based on 8032 is shown.

JP 2014-195147 A

ITU-T G. 8032 / Y. 1344 (02/2012)

  For example, as shown in Non-Patent Document 1, ITU-T G.I. A ring protocol represented by 8032 is known. In such a ring protocol, mainly one of the relay devices constituting the ring network controls the ring port to be blocked according to various events of the ring network represented by a failure or the like, and the contents of the event are determined. A method for notifying other relay devices via a control frame is defined.

  Further, a chassis-type relay device as disclosed in Patent Document 1 is known as one form of a relay device (L2 switch) that performs layer 2 (L2) processing of the OSI reference model. A chassis-type relay device may include a management card that manages the entire device including the line card in addition to a line card that transmits or receives a frame to / from the outside of the device. When a ring protocol is mounted on such a chassis-type relay device, the processing in the device can be made more efficient by mounting a ring protocol control unit mainly on the management card.

  Here, ITU-TG In 8032, as described above, it is defined that the ring port is controlled to be blocked or a control frame is transmitted in accordance with an event such as a failure. However, for example, there is no specific rule regarding a specific method, such as how to actually perform such processing. According to the study by the present inventors, particularly when using a chassis type relay device, there is a possibility of causing a problem such as generation of a loop route of a ring network unless the specific method described above is devised. It was found.

  The present invention has been made in view of the above, and an object of the present invention is to provide a relay device and a relay system capable of preventing the occurrence of a loop route in a ring network.

  Of the inventions disclosed in the present application, the outline of a typical embodiment will be briefly described as follows.

  The relay device according to the present embodiment includes a line card including a ring port connected to the ring network, and a management card that manages the line card. The management card includes a port control request unit and a control frame generation unit. The port control request unit determines to change the ring port from the open state to the blocked state in response to an event based on the ring protocol, and issues a ring port blocking command to the line card. The control frame generation unit generates a control frame based on the ring protocol, and transmits the control frame to the line card. The line card includes a port control unit and a control frame relay unit. The port control unit controls the ring port in a blocked state in response to a block command from the management card, and issues a block completion notification to the management card after completing the control to the blocked state. The control frame relay unit transmits a control frame from the management card from the ring port. Here, the control frame generation unit of the management card transmits the control frame to the line card after receiving the blockage completion notification.

  Of the inventions disclosed in this application, the effects obtained by the representative embodiments will be briefly described. It is possible to prevent the occurrence of a loop route in the ring network.

In the relay system by one embodiment of this invention, it is the schematic which shows the structural example and the operation example at the time of no failure. FIG. 2 is a schematic diagram illustrating an example of a failure monitoring method in the relay system of FIG. 1. FIG. 2 is a diagram illustrating an example of a main operation sequence when a failure occurs (SF) in the relay system of FIG. 1. In the relay system of FIG. 1, it is a figure which shows an example of the main operation | movement sequences at the time of failure recovery (SF cancellation). FIG. 2 is a block diagram illustrating a schematic configuration example of a main part of a relay device in the relay system of FIG. 1. It is a block diagram which shows the example of schematic structure of the principal part of each line card in FIG. FIG. 7 is an explanatory diagram illustrating an example of processing contents of an ICCM processing unit in the relay device of FIGS. 5 and 6. FIG. 7 is an explanatory diagram showing an example of a ring protocol operation at the time of detecting a failure occurrence as a premise in the relay device of FIGS. 5 and 6. It is explanatory drawing which shows the operation example following FIG. FIG. 10 is an explanatory diagram illustrating an operation example following FIG. FIG. 7 is an explanatory diagram showing an example of a ring protocol operation when receiving a presupposed R-APS (SF) frame in the relay apparatus of FIGS. 5 and 6. FIG. 7 is a conceptual diagram showing an example of a ring protocol operation according to the present embodiment in the relay device of FIGS. 5 and 6. It is a conceptual diagram which shows an example of the operation | movement sequence of the relay system corresponding to FIG. FIG. 13 is a flowchart showing an example of main processing contents of an ERP control unit for MC in the relay device of FIGS. 5, 6, and 12. FIG. 15 is a supplementary diagram for explaining part of the processing content of FIG. 14. FIG. 15 is a sequence diagram illustrating an example of a transmission method of a block instruction and a block completion notification in the flow of FIG. 14. FIG. 15 is a sequence diagram illustrating another example of a transmission method of a block instruction and a block completion notification in the flow of FIG. 14. (A) And (b) is explanatory drawing which shows the structural example of the ICCM frame in FIG. It is a figure which shows an example of the main operation | movement sequences at the time of failure recovery (SF cancellation) in the relay system examined as a comparative example of this invention. Each of (a) and (b) is a conceptual diagram showing an example of a ring protocol operation that can be a factor of a loop path in the relay apparatus studied as a comparative example of the present invention. It is a conceptual diagram which shows an example of the operation | movement sequence of the relay system corresponding to Fig.20 (a).

  In the following embodiment, when it is necessary for the sake of convenience, the description will be divided into a plurality of sections or embodiments. However, unless otherwise specified, they are not irrelevant, and one is the other. Some or all of the modifications, details, supplementary explanations, and the like are related. Further, in the following embodiments, when referring to the number of elements (including the number, numerical value, quantity, range, etc.), especially when clearly indicated and when clearly limited to a specific number in principle, etc. Except, it is not limited to the specific number, and may be more or less than the specific number.

  Further, in the following embodiments, the constituent elements (including element steps and the like) are not necessarily indispensable unless otherwise specified and apparently essential in principle. Needless to say. Similarly, in the following embodiments, when referring to the shapes, positional relationships, etc. of the components, etc., the shapes are substantially the same unless otherwise specified, or otherwise apparent in principle. And the like are included. The same applies to the above numerical values and ranges.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Note that components having the same function are denoted by the same reference symbols throughout the drawings for describing the embodiment, and the repetitive description thereof will be omitted.

<< Schematic configuration of relay system and schematic operation when there is no failure >>
FIG. 1 is a schematic diagram illustrating a configuration example and an operation example when there is no failure in a relay system according to an embodiment of the present invention. The relay system shown in FIG. 1 includes a plurality (four in this case) of relay devices SWa to SWd that constitute the ring network 10. Each of the relay devices SWa to SWd is also called a node. Each of the relay devices SWa to SWd includes two ring ports Pr [1] and Pr [2] and m user ports Pu [1] to Pu [m] (m is an integer of 1 or more). Prepare. In this example, the number of relay devices constituting the ring network 10 is four, but is not limited to this and may be two or more.

  The ring network 10 is, for example, an ITU-TG. It is controlled based on the ring protocol defined in 8032. In other words, each of the relay devices SWa to SWd has various control functions based on the ring protocol. Each of the relay devices SWa to SWd is an L2 switch that performs a layer 2 (L2) relay process of the OSI reference model, an L3 switch that performs a layer 3 (L3) relay process, and the like. However, since the relay processing on the ring network 10 is performed based on L2, here, each of the relay devices SWa to SWd is an L2 switch as an example.

  The two ring ports Pr [1] and Pr [2] are connected to the ring network 10, respectively. In other words, each of the relay devices SWa to SWd is connected in a ring shape via the ring ports Pr [1] and Pr [2], thereby forming the ring network 10. In the example of FIG. 1, the ring ports Pr [1] of the relay devices SWa, SWb, SWc, SWd are respectively connected to the ring ports Pr [2] of the adjacent relay devices SWb, SWc, SWd, SWa via the communication line. Connected to.

  User ports Pu [1] to Pu [m] are connected to a predetermined user network. In the example of FIG. 1, the user ports Pu [1] to Pu [m] of the relay devices SWa to SWd are connected to the user networks 11a to 11d, respectively. In each of the user networks 11a to 11d, a relay device and various information processing devices (such as a server device and a terminal device) are appropriately arranged.

  Here, ITU-TG Based on 8032, the relay device SWa is set as an owner node, and the relay device SWb is set as a neighbor node. The link between the owner node and the neighbor node is called RPL (Ring Protection Link). When there is no failure on the ring network 10, the relay device SWa controls the ring port Pr [1] located at one end of the RPL to the blocked state BK, and the relay device SWb is the ring port Pr located at the other end of the RPL. [2] is controlled to the closed state BK.

  A ring port in the blocked state BK prohibits passage of frames. When there is no failure in the ring network 10, the loop path of the frame on the ring network 10 is prevented by the RPL. As a result, a communication path 12 via the relay devices SWd and SWc is formed between the relay device SWa and the relay device SWb as shown in FIG. Frame transfer between the user networks 11a to 11d is performed on the communication path 12.

《Relay system failure monitoring method》
FIG. 2 is a schematic diagram illustrating an example of a failure monitoring method in the relay system of FIG. As shown in FIG. 2, each of the relay devices SWa to SWd includes monitoring points MEPa1 to MEPd1 corresponding to the ring port Pr [1], and the monitoring points MEPa2 to MEPd2 corresponding to the ring port Pr [2]. Prepare.

  ITU-T G. 8032 stipulates that the CC (Continuity Check) function of Ethernet (registered trademark) OAM is used to monitor the presence or absence of a link failure between relay devices. The Ethernet OAM is standardized by “ITU-T Y.1731”, “IEEE802.1ag”, etc., as a standard for monitoring communication between apparatuses. In the CC function, as shown in FIG. 2, a monitoring section is set by a monitoring point called MEP (Maintenance End Point). The MEPs at both ends of each monitoring section monitor the communication of each monitoring section by periodically transmitting and receiving a CCM (Continuity Check Message) frame that is a communication monitoring frame.

  In the example of FIG. 2, the monitoring point MEPa1 of the relay device SWa sets the CCM monitoring section 15ab with the monitoring point MEPb2 of the other device (SWb), and thereby the ring port Pr [1] of its own device, The communication with the ring port Pr [2] of the other device (SWb) connected thereto is monitored. On the other hand, the monitoring point MEPb2 of the relay device SWb also sets the CCM monitoring section 15ab with the monitoring point MEPa1 of the other device (SWa), thereby connecting to the ring port Pr [2] of its own device and to it. The communication with the ring port Pr [1] of the other device (SWa) is monitored.

  In the same manner, CCM monitoring sections 15bc, 15cd, and 15ad are sequentially set on the ring network 10. In each CCM monitoring section (for example, 15ab), when the monitoring point (MEPa1) at one end does not receive the CCM frame from the monitoring point (MEPb2) at the other end within a predetermined period, the monitoring point (MEPb2) at the other end The communication is determined as a LOC (Loss Of Continuity) state. The predetermined period is, for example, a period that is 3.5 times the CCM frame transmission interval (typically 3.3 ms).

  In this case, when the monitoring point (MEPa1) at one end transmits a CCM frame toward the monitoring point (MEPb2) at the other end, a flag is set in an RDI (Remote Defect Indication) bit included in the CCM frame. Send with. The monitoring point (MEPb2) at the other end receives the CCM frame flagged in the RDI bit from the monitoring point (MEPa1) at one end, and thereby determines the communication with the monitoring point (MEPa1) at one end from the RDI state. . Each of the relay devices SWa to SWd has their own ring ports Pr [1] and Pr [2] (links connected thereto) based on the presence or absence of the LOC state or RDI state at the monitoring point (MEP) of the own device. (Including) faults.

<< Operation in case of failure (SF) of relay system >>
FIG. 3 is a diagram showing an example of a main operation sequence when a failure occurs (SF) in the relay system of FIG. In FIG. 3, first, as a state before the occurrence of a failure (step S102), the ring port Pr [1] of the relay device SWa that is the owner node and the ring port Pr [2] of the relay device SWb that is the neighbor node are Both are controlled to the closed state BK. In addition, the relay devices SWa to SWd are all in the idle state based on the ring protocol. The idle state generally indicates that a special event typified by a failure or the like has not occurred.

  In this state, the relay device SWa, which is the owner node, is placed on the ring network 10 by the ITU-T G. R-APS (NR, RB) frames defined in 8032 are transmitted periodically (for example, every 5 s) (step S101). NR (No Request) represents no request, and RB (RPL Blocked) represents blocking of RPL. The R-APS (NR, RB) frame indicates that the ring network 10 has no failure, and accordingly the RPL (that is, the ring port Pr [1] of the relay device SWa) is controlled to the blocked state BK. This is a frame to be notified to the relay devices SWb to SWd.

  In such a state, as shown in step S102, it is assumed that a failure has occurred in the link between the relay device SWc and the relay device SWd. In this case, as shown in step S103b, the relay device SWc generates the failure (ITU) of the ring port Pr [1] (including the link connected thereto) based on the monitoring result at the monitoring point MEPc1 shown in FIG. -SF (Signal Fail) in TG 8032. In response to this, the relay device SWc controls the ring port Pr [1] to the blocked state BK, transmits the R-APS (SF) frame from the ring ports Pr [1], Pr [2], and the ring state From the idle state to the protection state.

  The R-APS (SF) frame functions as a failure notification frame. The protection state generally indicates that a failure has occurred on the ring network 10. Further, as shown in step S103a, the relay device SWd performs the same processing as that of the relay device SWc. The R-APS (SF) frame transmitted by the relay devices SWc and SWd is relayed by each relay device until it reaches the ring port in the blocked state BK.

  Here, as shown in step S104a, when the relay device SWa as the owner node receives the R-APS (SF) frame in the idle state, the relay device SWa stops the transmission of the R-APS (NR, RB) frame, and the ring The closed state BK of the port Pr [1] is released (that is, changed to the open state OP). The ring port in the open state OP permits passage of the frame. Further, when the relay device SWa receives the R-APS (SF) frame in the idle state, the relay device SWa changes the ring state from the idle state to the protection state. As shown in step S104b, the relay device SWb that is a neighbor node also receives the R-APS (SF) frame in the idle state, releases the blocked state BK of the ring port Pr [2], and changes the ring state from the idle state. Transition to the protection state.

  Thus, the various R-APS frames are control frames for controlling the ring network based on the ring protocol. Although various R-APS frames are not shown, in practice, they are first transmitted three times every 3.3 ms, and then transmitted every 5 s. In step S104a, more specifically, when the relay device SWa receives an R-APS (SF) frame in an idle state, it flushes an FDB (Forwarding DataBase). As described above, each of the relay devices SWa to SWd performs various processes including FDB flushing according to the combination of various ring states and various events. Therefore, description regarding such processing is omitted, and only main processing is described.

<< Operations at the time of relay system failure recovery (SF resolution) >>
FIG. 4 is a diagram showing an example of a main operation sequence at the time of failure recovery (SF resolution) in the relay system of FIG. In FIG. 4, as illustrated in FIG. 3, a case is assumed where the failure is recovered in a state where a failure has occurred in the link between the relay device SWc and the relay device SWd. First, in a state where a failure has occurred, both the ring port Pr [1] of the relay device SWc and the ring port Pr [2] of the relay device SWd are controlled to the blocked state BK. Further, as shown in FIG. 3, the relay devices SWa to SWd both have the ring state in the protection state. In such a state, when the failure is recovered (step S201), the following processing is performed.

  As shown in step S202b, the relay device SWc detects failure recovery (Clear SF in ITU-T G.8032) of the ring port Pr [1] using the monitoring point MEPc1. In response to this, the relay device SWc transmits an R-APS (NR) frame from the ring ports Pr [1] and Pr [2], and changes the ring state from the protection state to the pending state. The R-APS (NR) frame functions as a failure recovery frame. The pending state generally indicates that the state of the ring network 10 is not clearly determined. Further, as shown in step S202a, the relay device SWd performs the same processing as that of the relay device SWc.

  As shown in step S203a, when receiving the R-APS (NR) frame in the protection state, the relay device SWa that is the owner node starts a WTR (Wait To Restore) timer and changes the ring state from the protection state to the pending state. Transition. Also, as illustrated in step S203b, when the relay device SWb, which is a neighbor node, receives the R-APS (NR) frame in the protection state, the ring state transitions from the protection state to the pending state.

  On the other hand, as shown in step S204, each of the relay devices SWc and SWd receives an R-APS (NR) frame from the other during a guard timer period (not shown) and is included in the R-APS (NR) frame. Based on the priority information, it is determined whether or not to change the ring port of the blocking state BK of the own apparatus to the open state OP. In this example, based on such a determination result, the relay device SWc releases the blocked state BK of the ring port Pr [1] and also stops transmission of the R-APS (NR) frame.

  In step S205, when the period of the WTR timer expires in the pending state, the relay device SWa changes the RPL (that is, the ring port Pr [1]) from the open state OP to the blocked state BK. Further, the relay device SWa transmits an R-APS (NR, RB) frame from the ring ports Pr [1] and Pr [2], and changes the ring state from the pending state to the idle state.

  In step S206a, when the relay device SWd receives the R-APS (NR, RB) frame in the pending state, the relay device SWd stops transmission of the R-APS (NR) frame and releases the blocking state BK of the ring port Pr [2]. Then, the ring state is changed from the pending state to the idle state. In step S206b, when the relay device SWc receives the R-APS (NR, RB) frame in the pending state, the relay device SWc changes the ring state from the pending state to the idle state.

  On the other hand, when the relay device SWb, which is a neighbor note, receives the R-APS (NR, RB) frame in the pending state in step S206c, the relay device SWb changes the RPL (that is, the ring port Pr [2]) from the open state OP to the blocked state BK. Change and change the ring state from the pending state to the idle state. As a result of such processing, the normal state as shown in step S101 of FIGS. 1 and 3 is restored.

  As described above, for example, ITU-TG The ring protocol processing based on 8032 is performed based on the state transition. In supplementary explanation, first, as a ring state, an FS (Forced Switch) state and an MS (Manual Switch) state are defined in addition to the idle state, the protection state, and the pending state shown in FIGS. The FS state and the MS state are states in which the ring port based on the user's instruction is controlled to be closed.

  Then, in accordance with the combination of the ring state and the event, what kind of control is performed and what is output, and which ring state is to be changed next are defined. As an event, for example, a local event that occurs directly in the own device, such as SF detection shown in step S103a in FIG. 3, or an R-APS that occurs in another device, as shown in step S104a in FIG. There is a remote event notified from another device via a frame.

《Relay device configuration》
FIG. 5 is a block diagram illustrating a schematic configuration example of a main part of the relay apparatus in the relay system of FIG. FIG. 6 is a block diagram illustrating a schematic configuration example of a main part of each line card in FIG. The relay apparatus shown in FIG. 5 is applied to at least one of the relay apparatuses SWa to SWd shown in FIG.

  The relay device shown in FIG. 5 is a chassis-type relay device in which a plurality of cards are mounted in one housing. The relay device includes a plurality (here, n) of line cards LC [1] to LC [n], a management card MC, and a fabric path unit 20. Each of the line cards LC [1] to LC [n] performs frame communication (transmission and reception) with the outside of the apparatus. The fabric path unit 20 mediates communication between the plurality of line cards LC [1] to LC [n], and further, the management card MC and each of the plurality of line cards LC [1] to LC [n]. Mediate communication between them. Specifically, the fabric path unit 20 may be configured by, for example, a mesh-like wiring or a fabric card.

  Although not shown, the management card MC is a general management function that manages various settings and states of the plurality of line cards LC [1] to LC [n] based on instructions from the user, for example. Is provided. The management card MC includes an MC ERP control unit 22, a storage unit 23, and a fabric interface unit 27 in addition to such a general management function. The MC ERP control unit 22 functions as a ring control unit and mainly performs various processes based on a predetermined ring protocol (here, ITU-T G.8032) while using information in the storage unit 23. Although described in detail later, the MC ERP control unit 22 includes a VID filter control request unit (port control request unit) 25 and an R-APS generation unit (control frame generation unit) 26.

  The fabric interface unit 27 includes an ICCM processing unit 24 and mediates communication between the self-management card and the fabric path unit 20. An ICCM processing unit (internal communication monitoring unit) 24 communicates with each of the plurality of line cards LC [1] to LC [n] via the fabric path unit 20 (hereinafter referred to as an ICCM frame). Communication) is periodically performed to monitor the presence / absence of communication with each of a plurality of line cards. Further, the ICCM processing unit 24 mediates communication between the MC ERP control unit 22 and each of the plurality of line cards using the ICCM frame.

  The plurality of line cards LC [1] to LC [n] include the ring ports Pr [1] and Pr [2] and user ports Pu [1] to Pu [m] illustrated in FIG. In the example of FIG. 5, the line cards LC [1] and LC [2] include ring ports Pr [1] and Pr [2], respectively, and the line card LC [n] includes the user port Pu [1]. I have. However, which line card is provided with each port is not limited to the example of FIG. 5 and can be arbitrarily determined.

  Each of the plurality of line cards LC [1] to LC [n] has a configuration as shown in FIG. 6 in detail. The line card LC of FIG. 6 includes an interface unit 30, a frame processing unit 31, an FDB, an LC ERP control unit 32, and a fabric interface unit 33. Here, for convenience of explanation, it is assumed that the line card LC includes a plurality of ports including a ring port Pr and a user port Pu.

  The interface unit 30 includes a reception port identifier adding unit 34, a frame determination unit 35, a VID filter 36, and an OAM processing unit 37, and mainly transmits and receives frames to and from a plurality of ports. When the reception port identifier adding unit 34 receives a frame at any of a plurality of ports, the reception port identifier adding unit 34 adds a reception port identifier representing the reception port to the frame. The frame discriminating unit 35 discriminates the format of the frame, for example, whether the received frame is a user frame format or an R-APS frame format.

  The VID filter 36 controls whether or not frames can be passed based on the set conditions. For example, when a frame having a predetermined VLAN identifier VID is received at a predetermined port, the frame is discarded, or when a frame having a predetermined VLAN identifier VID is transmitted from a predetermined port, the frame should be transmitted. The condition of discarding without setting is set. The VID filter 36 performs processing based on the conditions. The actual closed state BK and open state OP of the ring port are constructed by the VID filter 36.

  The OAM processing unit 37 includes the MEP as shown in FIG. 2 and communicates a communication monitoring frame (specifically, a CCM frame) with the outside of the apparatus via the ring port Pr, thereby causing the ring port Pr to communicate. Monitor the presence or absence of failures. When the received frame is a user frame, the interface unit 30 transmits the frame to the frame processing unit 31. When the received frame is an R-APS frame, the interface unit 30 transmits the frame to the LC ERP control unit 32. Send. Further, when the interface unit 30 receives a frame to which a destination port identifier representing the destination port of the frame is added from the frame processing unit 31 or the LC ERP control unit 32, the interface unit 30 transmits the frame to the destination port.

  The FDB holds a correspondence relationship between a MAC (Media Access Control) address, a VLAN identifier VID, and a port. In addition, when the port is a ring port, the FDB additionally stores a ring ID. The ring ID is used as a key when determining an entry to be FDB flushed. The frame processing unit 31 includes an FDB processing unit 38, an FDB synchronization unit 39, and an ICCM processing unit 40. The FDB processing unit 38 performs FDB learning and search when a user frame is received at a port. Specifically, the FDB processing unit 38 associates the transmission source MAC address of the received user frame with the VLAN identifier VID and the reception port identifier (including the line card identifier) added by the interface unit 30. Learn to FDB.

  Further, the FDB processing unit 38 searches the FDB using the destination MAC address and VLAN identifier VID of the received user frame as a search key, and acquires the destination port identifier (including the line card identifier). When the destination port identifier is the port identifier of the own line card, the FDB processing unit 38 directly transmits the user frame to which the destination port identifier is added to the interface unit 30 or returns the user frame by the fabric interface unit 33 or the fabric path unit 20. To the interface unit 30. On the other hand, when the destination port identifier is a port identifier of another line card, the FDB processing unit 38 transmits the user frame with the destination port identifier added to the fabric path unit 20 via the fabric interface unit 33. The fabric path unit 20 transmits the user frame to the line card based on the destination port identifier.

  The FDB synchronization unit 39 has a function of synchronizing the contents held in the FDB among the plurality of line cards LC [1] to LC [n]. Specifically, for example, when the FDB synchronization unit 39 receives a frame at the port of its own line card, the FDB synchronization unit 39 generates a learning frame including the reception port identifier and the header portion of the frame, and passes through the fabric path unit 20. To other line cards. The FDB synchronization unit 39 of another line card performs FDB learning based on the learning frame.

  The ICCM processing unit (internal communication monitoring unit) 40 periodically communicates the ICCM frame with each of the management card MC and the other line card LC, so that the management card MC and the other line card LC Monitor communication with each other. Further, the ICCM processing unit 40 mediates communication between the LC ERP control unit 32 and the management card MC using the ICCM frame.

  The LC ERP control unit 32 functions as a ring control unit, and subordinately performs various processes based on a predetermined ring protocol (here, ITU-T G.8032) based on the MC ERP control unit 22. The LC ERP control unit 32 includes an R-APS relay unit 41, a port control unit 42, and a port management table 43.

  The R-APS relay unit (control frame relay unit) 41 relays the R-APS frame received at the ring port Pr to the management card MC via the fabric interface unit 33. On the other hand, the R-APS relay unit 41 transmits the R-APS frame from the management card MC from the ring port Pr. Further, the R-APS relay unit 41 relays the R-APS frame received in one of the two ring ports to the other of the two ring ports. The port control unit 42 controls opening / closing of the VLAN identifier VID and the ring port Pr specified by the command in response to an open command or block command from the management card MC. The port management table 43 holds the VLAN identifier VID and the opening / closing information of the ring port Pr based on the control.

  The fabric interface unit 33 transmits the frame (user frame, ICCM frame, learning frame) transmitted from the frame processing unit 31 and the R-APS frame relayed by the R-APS relay unit 41 to the fabric path unit 20. To do. Further, the fabric interface unit 33 transmits the frame transmitted from the fabric path unit 20 to the frame processing unit 31 or the LC ERP control unit 32.

  In the management card MC of FIG. 5, the MC ERP control unit 22 is realized by a program process or the like by a processor (CPU), the storage unit 23 is realized by a RAM or the like, and the fabric interface unit 27 is an FPGA (Field (Programmable Gate Array) etc. In the line card LC of FIG. 6, each of the interface unit 30 and the fabric interface unit 33 is mounted on an ASIC (Application Specific Integrated Circuit) or the like. The frame processing unit 31 and the LC ERP control unit 32 are mounted on an FPGA or the like. The FDB is mounted on a CAM (Content Addressable Memory) or the like. However, the specific mounting form of each part is of course not limited to this, and may be appropriately mounted using hardware, software, or a combination thereof.

《Relay device internal communication monitoring operation》
FIG. 7 is an explanatory diagram showing an example of processing contents of the ICCM processing unit in the relay device of FIGS. 5 and 6. 7, the ICCM processing units (internal communication monitoring units) 40 of the line cards LC [1], LC [2],..., LC [n] include internal monitoring points IMEP1l, IMEP2l,. . On the other hand, the ICCM processing unit (internal communication monitoring unit) 24 of the management card MC includes internal monitoring points IMEP1m, IMEP2m, ..., IMEPnm.

  Each of the internal monitoring point IMEP1m of the management card MC and the internal monitoring point IMEP1l of the line card LC [1] sets an ICCM monitoring section with the other party, and periodically communicates with the other party by periodically communicating with the ICCM frame ICCM1. Monitor for communication with the network. Similarly, the internal monitoring points IMEP2m,..., IMEPnm of the management card MC and the internal monitoring points IMEP2l,..., IMEPnl of each line card respectively set an ICCM monitoring section with the other party, and an ICCM frame ICCM2,. The presence or absence of communication with the other party is monitored by periodically performing ICCMn communication.

  The ICCM frame (internal communication monitoring frame) is the same frame as the CCM frame (communication monitoring frame) described above. That is, in this embodiment, the Ethernet OAM standard for monitoring communication between devices is used, and a method similar to this is applied to monitoring of communication within the device. Then, an ICCM frame is used instead of the CCM frame as a monitoring frame for monitoring the communication inside the apparatus. When the internal communication is monitored using the ICCM frame, the internal communication presence / absence (failure presence / absence) is determined based on the presence / absence of the LOC state or the RDI state as in the case of the CCM frame described above.

  Although not necessarily limited, the ICCM frame transmission interval is preferably equal to or shorter than the CCM frame transmission interval. In the present embodiment, for example, the transmission interval of the ICCM frame is 1 ms or the like, and the transmission interval of the CCM frame is 3.5 ms or the like. Further, here, each of the line cards LC [1] to LC [n] (for example, LC [1]) monitors the presence or absence of communication with the management card MC. The presence / absence of communication with each of the line cards (for example, LC [2] to LC [n]) is also monitored.

<< Ring protocol operation when failure of relay device is detected (prerequisite) >>
FIG. 8 is an explanatory diagram showing an example of a ring protocol operation when a failure occurrence is detected in the relay apparatus of FIGS. 5 and 6. FIG. 9 is an explanatory diagram illustrating an operation example following FIG. 8, and FIG. 10 is an explanatory diagram illustrating an operation example following FIG. FIGS. 8 to 10 show examples of operations in steps S102 and S103b, taking the relay device SWc of FIG. 3 as an example.

  In FIG. 8, first, the OAM processing unit 37 of the line card LC [1] having the ring port Pr [1] detects a failure occurrence (for example, LOC state) of the ring port Pr [1] (steps S102, S102-). 1). In this case, the LC ERP control unit 32 of the line card LC [1] stores the failure information in the ICCM frame ICCM1 transmitted from the ICCM processing unit 40 (step S102-2). The failure information is, for example, an identifier of a failure occurrence location (here, {LC [1]} / {Pr [1]}). In this specification, for example, {AA} represents an identifier of “AA”.

  The ICCM processing unit 24 of the management card MC receives the ICCM frame ICCM1 in which the failure information is stored (step S102-3). When the ECM control unit 22 for MC receives the ICCM frame in which the failure information is stored in the ICCM processing unit 24, the ITU-T G. Failure occurrence (SF) based on 8032 is detected (step S103b-1). In this case, as shown in FIG. 9, the MC ERP control unit 22 refers to the ring management table 45 set in advance in the storage unit 23, and is connected to the ring network to which the failure location belongs and the ring network. Recognizes a ring port.

  In the example of FIG. 9, the ring management table 45 holds a ring ID assigned to each ring network, a VLAN identifier VID and a ring port ID belonging to each ring ID, and opening / closing information for each ring port ID. Here, the ring port ID of VLAN identifier VID = 1 (specifically, line card ID / port ID) {LC [1]} / {Pr [1]} and {LC [2]} / {Pr [2] } Belongs to the ring network with ring ID = 1, and the ring ports Pr [1] and Pr [2] are both in the open state OP. The MC ERP control unit 22 refers to the ring management table 45 using the failure information (here, {LC [1]} / {Pr [1]}), so that which ring network (ring ID) has a failure. Can be recognized.

  In the example of FIG. 1 and the like, the relay system includes one ring network 10, but in the case of including a plurality of ring networks, the ring management table 45 includes a ring ID for each ring network and the ring ID. VLAN identifier VID and ring port ID belonging to the are set. For example, the ring management table 45 includes a ring ID = 2, a VLAN identifier VID = 2, a ring port ID = “{LC [1]} / {Pr [1]} and {LC [2]} / {Pr [2]. ]} ”Etc. are set.

  Based on the received failure information ({LC [1]} / {Pr [1]}), the VID filter control request unit (port control request unit) 25 of the MC ERP control unit 22 uses the ring port Pr of the failure location. [1] and a VID control command (blocking command) for controlling the VLAN identifier VID to the blocking state BK are issued (step S103b-2). In addition, the VID filter control request unit 25 changes the opening / closing information of the ring port Pr [1] of the ring management table 45 from the open state OP to the closed state BK when the block command is issued. Then, the MC ERP control unit 22 stores the VID control command (blocking command) in the ICCM frame ICCM1 transmitted from the ICCM processing unit 24 toward the line card LC [1] (step S103b-3). .

  Further, the MC ERP control unit 22 actually issues an FDB flush execution instruction in addition to the block instruction (step S103b-2), and sends the execution instruction to each ICCM frame ICCM1, ICCM2,. Store (step S103b-3). At this time, the MC ERP control unit 22 determines a ring ID (that is, a ring ID in which a failure has been detected) to be FDB flushed based on the ring management table 45, and sets the ring ID as an FDB flush execution instruction. Specify in.

  The ICCM processing unit 40 of the line card LC [1] receives the ICCM frame ICCM1 in which the block instruction and the FDB flush execution instruction are stored (step S103b-3). The LC ERP control unit 32 (specifically, the port control unit 42) of the line card LC [1] controls the VID filter 36 in accordance with the block command included in the ICCM frame ICCM1, and the target ring port ( Here, Pr [1]) and the VLAN identifier VID (here, “1”) are actually controlled to the blocked state BK (step S103b-4). In addition, the LC ERP control unit 32 flushes the FDB entry including the specified ring ID in accordance with the FDB flush execution command included in the ICCM frame ICCM1. Similarly, the other line cards LC [2],... Execute the FDB flush execution command.

  Further, as shown in FIG. 10, the R-APS generation unit (control frame generation unit) 26 of the MC ERP control unit 22 generates an R-APS (SF) frame in response to the execution of the block instruction described above. Is performed (step S103b-9). Specifically, the R-APS generator 26 generates two R-APS (SF) frames including a predetermined ring ID and a predetermined VLAN identifier VID based on the ring management table 45. The R-APS generation unit 26 adds destination port identifiers (here, {LC [1]} / {Pr [1]} and {LC [2]} / {) to the two generated R-APS (SF) frames, respectively. Pr [2]}) is added and transmitted to the fabric path unit 20 via the fabric interface unit 27.

  Further, the MC ERP control unit 22 changes the ring state of the own device from the idle state to the protection state (step S103b-10). On the other hand, the R-APS relay unit (control frame relay unit) 41 of each of the line cards LC [1] and LC [2] receives the R-APS (SF) frame from the management card MC and sends it to the interface unit. 30 from the destination ring ports Pr [1], Pr [2].

<< Ring protocol operation when R-APS (SF) is received by relay apparatus (premise) >>
FIG. 11 is an explanatory diagram showing an example of a ring protocol operation when receiving the R-APS (SF) frame as a premise in the relay apparatus of FIGS. 5 and 6. FIG. 11 shows an operation example in step S104a, taking the relay device SWa of FIG. 3 as an example.

  In FIG. 11, the R-APS relay unit 41 of the LC ERP control unit 32 of the line card LC [2] receives the R-APS (SF) frame received by the ring port Pr [2] via the interface unit 30. (Step S104a-1). The R-APS relay unit 41 relays the received frame to the ring port Pr [1] via the fabric path unit 20 (step S104a-2).

  In addition, the R-APS relay unit 41 determines, for example, whether or not the received R-APS (SF) frame is a frame to be received by the own device, and if it is a frame to be received by the own device, The frame is transmitted to the management card MC (step S104a-3). Specifically, the R-APS relay unit 41 holds, for example, the same information as the ring management table 45 illustrated in FIG. 9 and determines whether or not the own device should receive the received R-APS frame. And whether the VLAN identifier VID matches between the ring port and the ring port.

  The MC ERP control unit 22 of the management card MC receives the R-APS (SF) frame. The VID control request unit 25 of the MC ERP control unit 22 recognizes the ring network that is the target of the SF by referring to the ring ID of the received R-APS (SF) frame. In this example, since the MC ERP control unit 22 belongs to the owner node in the ring network, the VID control request unit 25 sets the RPL (that is, VLAN identifier VID = 1 and ring port Pr [1]). A VID control command (open command) for controlling the open state OP is issued (step S104a-4).

  In addition, the MC ERP control unit 22 actually issues an FDB flush execution instruction in addition to the release instruction (step S104a-4). The MC ERP control unit 22 stores the release command and the FDB flush execution command in the ICCM frame ICCM1 directed to the line card LC [1] transmitted from the ICCM processing unit 24 (step S104a-5). Further, the MC ERP control unit 22 changes the ring state of the own device from the idle state to the protection state (step S104a-6).

  Although not shown, the MC ERP control unit 22 issues an FDB flush execution command to the other line cards LC [2],... As in the case of FIG. The LC ERP control unit 32 of each line card LC [1], LC [2],... Is omitted, but the VID from the MC ERP control unit 22 is the same as in FIG. Processing is performed in accordance with a control command or an FDB flash execution command.

  As described above, in the relay apparatus of FIGS. 5 and 6, the MC ERP control unit 22 of the management card MC has a method of performing the ring protocol operation mainly. As a typical example, the management card MC determines that the ring port is changed from the open state OP to the blocked state BK or from the blocked state BK to the open state OP in accordance with an event based on the ring protocol, and the ring port is transferred to the line card. Issue a block or open command. On the other hand, the LC ERP control unit 32 of the line card performs the ring protocol operation in a dependent manner by simply executing a command from the MC ERP control unit 22.

<< Ring protocol operation of relay system (comparative example) and its problems >>
FIG. 19 is a diagram showing an example of a main operation sequence at the time of failure recovery (SF resolution) in the relay system studied as a comparative example of the present invention. The operation sequence shown in FIG. 19 is obtained by replacing the processing contents of steps S205 and S206a in FIG. 4 described above with steps S205 ′ and S206a ′ in FIG. In step S205 ′, the relay device SWa transmits the R-APS (NR, RB) frame upon expiration of the WTR timer, and then controls the RPL (that is, the ring port Pr [1]) to the blocked state BK. Yes.

  Further, in step S206a ′, the relay device SWd changes the ring port Pr [2] from the blocked state BK to the open state OP according to the received R-APS (NR, RB) frame, and thereafter, the R-APS (NR, RB) frame. The transmission of the APS (NR) frame is stopped. Here, when it takes time from transmission of the R-APS (NR, RB) frame to blocking the RPL in step S205, or depending on the R-APS (NR, RB) frame in step S206a ′. Assume a case where the ring port is opened at time. In this case, as shown at time t = t1, a loop route may be generated in the ring network when the ring port is opened in step S206a '.

  20A and 20B are conceptual diagrams showing an example of a ring protocol operation that can cause a loop path in the relay apparatus studied as a comparative example of the present invention. FIG. 21 is a conceptual diagram showing an example of an operation sequence of the relay system corresponding to FIG.

  First, in the example of FIG. 20A, the MC ERP control unit 22 of the relay apparatus as a comparative example changes the ring port from the open state OP to the blocked state BK according to an event based on the ring protocol. After transmitting a control frame (for example, R-APS frame) CF, a ring port blocking command is issued after a period T1 ′. Further, the MC ERP control unit 22 issues a ring port release command when changing the ring port from the closed state BK to the open state OP according to an event based on the ring protocol, and then passes through a period T2 ′. Transmission of the control frame CF is stopped.

  Here, for example, ITU-TG In 8032, it is stipulated that the open / close state of the ring port is changed according to the event and that the transmission of the R-APS frame is started or stopped, but the order is not stipulated. In addition, ITU-T G.I. With 8032 as a representative example, in many general ring protocols, a relay apparatus having a ring port in the blocked state BK transmits a control frame CF, and a relay apparatus having no ring port in the blocked state BK does not transmit a control frame CF. The specifications are as follows.

  In this case, the control frame CF often includes the meaning of notifying other relay apparatuses that the ring port is not blocked. As a result, as shown in FIG. 20A, after the MC ERP control unit 22 starts transmitting the control frame CF, the line card LC actually sets the ring port according to the block command from the MC ERP control unit 22. In the period T3 ′ until the block is closed, a loop route may occur in the ring network. In addition, even in the period T4 ′ from when the line card LC actually opens the ring port according to the release command from the MC ERP control unit 22 until the MC ERP control unit 22 stops transmitting the control frame CF, the loop is also executed. There is a risk that a route will occur.

  Specifically, as shown in FIG. 21, when the relay device SW1 ′ changes the ring port Pr from the open state OP to the blocked state BK according to a predetermined event, the relay device SW1 ′ controls the control frame toward the relay device SW2 ′. After transmitting the CF, the ring port Pr is changed to the blocked state BK after a period T3 ′ (step S1001 ′). On the other hand, the relay device SW2 ′ changes the ring port Pr from the blocked state BK to the opened state OP in a period shorter than the period T3 ′ in accordance with the received control frame CF (in other words, notification of blocking unnecessary) (step S3). S1002 '). As a result, a loop path may occur in a period T3a ′ from when the ring port Pr of the relay device SW2 ′ is opened until the ring port Pr of the relay device SW1 ′ is closed.

  In step S1003 ′ of FIG. 21, the relay device SW2 ′ changes the ring port Pr from the open state OP to the blocked state BK according to a predetermined event, and transmits the control frame CF toward the relay device SW1 ′. . When the relay device SW1 ′ changes the ring port Pr from the closed state BK to the open state OP according to the control frame CF, the relay device SW1 ′ opens the ring port Pr and then goes to the relay device SW2 ′ after a period T4 ′. The transmission of the control frame CF is stopped (step S1004 ′). Here, if the relay device SW2 'opens the ring port Pr in response to the control frame CF (in other words, notification of no need for blocking) in this period T4', a loop route may occur.

  Next, in the example of FIG. 20B, when the ERP control unit 22 for MC of the relay apparatus as a comparative example changes the ring port from the open state OP to the blocked state BK according to the event based on the ring protocol. Unlike the case of FIG. 20A, after issuing a ring port blocking command, transmission of the control frame CF is started after a period T5 ′. However, here, a delay period Tdly longer than the period T5 'occurs after the block command is issued until the ring port is actually blocked. As a result, after the MC ERP control unit 22 starts transmitting the control frame CF, the loop is performed in a period T6 ′ until the line card LC actually closes the ring port according to the block command from the MC ERP control unit 22. Paths can occur.

  The problem as shown in FIG. 20B is particularly caused by using the chassis-type relay device to execute the processing of steps S103b-3 and S103b-4 in FIG. 9 (issuing and executing the blocking instruction) and the step in FIG. This is highly likely to occur when the processing of S103b-9 (R-APS frame generation and transmission) is performed. For example, when the processing load of the line card LC [1] in FIG. 9 is heavy and the processing load of the line card LC [2] in FIG. 10 is light, R-APS (SF before the ring port Pr [1] is blocked. ) There is a possibility that a frame is transmitted from the ring port Pr [2]. Therefore, it is beneficial to use the method of this embodiment shown below.

<< Ring protocol operation of relay system (this embodiment) >>
FIG. 12 is a conceptual diagram showing an example of the ring protocol operation according to the present embodiment in the relay apparatus of FIGS. FIG. 13 is a conceptual diagram showing an example of an operation sequence of the relay system corresponding to FIG.

  As shown in FIG. 12, the MC ERP control unit 22 of the relay device according to the present embodiment changes the ring port from the open state OP to the blocked state BK according to the event based on the ring protocol. After issuing a ring port block command, the system waits for a block completion notification from the line card. Then, the MC ERP control unit 22 transmits a control frame (for example, an R-APS frame) CF to the line card after receiving the blockage completion notification from the line card. In addition, when the MC ERP control unit 22 changes the ring port from the blocked state BK to the opened state OP in response to an event based on the ring protocol, the MC ERP control unit 22 stops transmitting the control frame CF and then transfers the ring port to the line card. Issue the release command.

  When such a method is used, as shown in FIG. 13, when the relay device SW1 changes the ring port Pr from the open state OP to the closed state BK according to a predetermined event, the relay device SW1 controls to the closed state BK. After the process is reliably completed, the control frame CF is transmitted to the relay device SW2 (step S1001). The relay device SW2 changes the ring port Pr from the blocked state BK to the opened state OP in response to the control frame CF (in other words, notification that blocking is unnecessary) (step S1002).

  As a result, unlike the case of FIG. 21, the ring port Pr of the relay device SW1 is reliably in the blocked state BK when the ring port Pr of the relay device SW2 is changed to the open state OP (t = t2). Therefore, a loop route does not occur in the ring network. Further, unlike the case of FIG. 20B, the relay device SW1 transmits the control frame CF after confirming that the ring port Pr has been reliably controlled to the blocked state BK, so that no loop path is generated.

  Further, in FIG. 13, when the relay device SW1 changes the ring port Pr from the closed state BK to the open state OP according to the control frame CF (step S1003) from the relay device SW2, the relay device SW1 is directed to the relay device SW2. After stopping transmission of the control frame CF, the ring port Pr is controlled to the open state OP (step S1004). As a result, the relay device SW2 does not receive the control frame CF as in the case of the period T4 'in FIG. 21, and no loop path is generated in the ring network.

<Details of ERP controller for MC>
FIG. 14 is a flowchart showing an example of main processing contents of the ERP control unit for MC in the relay apparatus of FIGS. 5, 6, and 12. FIG. 15 is a supplementary diagram for explaining a part of the processing contents of FIG. In FIG. 14, the MC ERP control unit 22 determines whether an event based on the ring protocol has occurred on the ring network (step S301). The event based on the ring protocol is the local event or the remote event described with reference to FIGS.

  The MC ERP control unit 22 ends the process when no event has occurred. On the other hand, when an event occurs, the MC ERP control unit 22 (specifically, the VID filter control request unit 25) determines whether to open or close the ring port Pr based on the ring protocol, and starts from the open state OP of the ring port Pr. It is determined whether or not a change to the closed state BK or a change from the closed state BK to the open state OP is necessary (step S302).

  Here, when the change from the blocked state BK to the open state OP is necessary (step S303), the R-APS generation unit (control frame generation unit) 26 first stops transmission of the R-APS frame (control frame). (Step S310). The VID filter control request unit (port control request unit) 25 then issues a ring port release command to the line card having the target ring port after the R-APS generation unit 26 stops transmitting the R-APS frame. A VID control instruction including this is issued (step S311).

  Thereafter, the MC ERP control unit 22 executes a predetermined process based on the ring protocol such as execution of FDB flush (step S307). In the example of FIG. 5, the MC ERP control unit 22 is configured by, for example, program processing by the CPU. In this case, the processing order of steps S310 and S311 can be determined on the program.

  Regarding steps S303, S310, and S311, the following two exceptions are actually conceivable. The first is, for example, a case where failure recovery is detected in a situation where an R-APS (SF) frame is transmitted in response to a failure occurrence (SF). In this case, the ERP control unit 22 for MC stops the R-APS (SF) frame (notification of blocking unnecessary) in response to the detection of the failure recovery (step S310), but instead notifies the failure recovery. After starting the transmission of the APS (NR) frame, a release command is issued (step S311). The R-APS (NR) frame at this time means requesting the other node (for example, the owner node) to be blocked in order to open the ring port of the own node. As described above, when the R-APS frame means not-needing notification but not-needing notification, the MC ERP control unit 22 transmits the R-APS frame prior to the release command.

  The second case is a case where an R-APS (FS) frame is received in a situation where an R-APS (SF) frame is transmitted in response to a failure occurrence (SF), for example. The R-APS (FS) frame at this time is a frame that requests the other node to open the ring port when the highest priority blocked port is provided on the ring network. In this case, the MC ERP control unit 22 is required to open the ring port early in response to the request. Therefore, the MC ERP control unit 22 first performs the process of step S311 (that is, issues the release command), and then performs the process of step S310 (that is, stops transmission of the R-APS (SF) frame). Also good. When such an order is used, a problem occurs when the switch device SW2 ′ opens the ring port as shown in step S1004 ′ of FIG. 21, but the switch device SW2 ′ has a ring state of FS. In the state, the ring port is not opened.

  On the other hand, if a change from the open state OP to the blocked state BK is necessary in step S303, first, the VID filter control request unit 25 sends a VID control command including a ring port blocking command to the line card having the target ring port. Is issued (step S304). Next, the R-APS generation unit 26 waits to receive a blockage completion notification from the line card (step S305). The R-APS generator 26 transmits the R-APS frame to the line card having the ring port after receiving the blockage completion notification (step S306).

  Regarding steps S304 and S305, specifically, as shown in FIG. 15, the VID filter control request unit 25 transmits the ICCM frame ICCM1 transmitted toward the line card LC [1], as in FIG. The VID control instruction including the closing instruction for the ring port Pr [1] is stored (step S103b-3). The LC ERP control unit 32 of the line card LC [1] receives the VID control command included in the ICCM frame ICCM1 via the ICCM processing unit 40.

  The port control unit 42 of the LC ERP control unit 32 actually controls the ring port Pr [1] to the blocked state BK according to the blocked command included in the VID control command (step S103b-4). Specifically, the port control unit 42 controls the VID filter 36 so that the ring port Pr [1] (specifically, a combination of the ring port Pr [1] and a predetermined VLAN identifier VID) is blocked. Set up.

  Then, after completing the control to the blocked state BK, the port control unit 42 updates the information in the port management table 43 (step S103b-5), and notifies the management card MC of the completion of blocking the ring port Pr [1]. Is issued (step S103b-6). In this example, the port control unit 42 stores the blockage completion notification in the ICCM frame ICCM1 transmitted toward the management card MC (step S103b-7). When the R-APS generation unit 26 of the management card MC receives the blockage completion notification via the ICCM processing unit 24 (step S103b-8), as in the case of step S103b-9 in FIG. An APS frame is generated and transmitted.

  Returning to FIG. 14, after transmitting the R-APS frame in step S306, the MC ERP control unit 22 executes predetermined processing based on the ring protocol such as execution of FDB flush (step S307). On the other hand, in step S305, if the ERP control unit 22 for MC cannot receive the blockage completion notification from the line card for a predetermined period (step S308), it performs a predetermined error process (step S309). Further, the MC ERP control unit 22 executes a predetermined process based on the ring protocol when it is not necessary to change the open / close state of the ring port in step S302 (step S307).

<< Transmission method of shutdown command and shutdown completion notification >>
FIG. 16 is a sequence diagram illustrating an example of a transmission method of a block instruction and a block completion notification in the flow of FIG. In FIG. 16, the MC ERP control unit 22 of the management card MC requests the ICCM processing unit 24 to transmit a block command when it is necessary to change the ring port from the open state OP to the block state BK. Interrupt. In response to the interrupt, the ICCM processing unit 24 transmits an ICCM frame including a block command to the line card LC (step S304).

  On the other hand, the LC ERP control unit 32 of the line card LC controls the predetermined ring port to the blocked state BK in response to the blocking command (step S400), and then, similarly to the management card MC, the ICCM processing unit 40 Is interrupted to request transmission of the closure completion notification. In response to the interrupt, the ICCM processing unit 40 transmits an ICCM frame including a blockage completion notification to the management card MC (step S401). After receiving the blockage completion notification (step S305), the MC ERP control unit 22 of the management card MC transmits an R-APS frame to the line card LC (step S306).

  FIG. 17 is a sequence diagram showing another example of the transmission method of the block command and the block completion notification in the flow of FIG. 18 (a) and 18 (b) are explanatory diagrams showing an example of the structure of the ICCM frame in FIG. In the example of FIG. 17, each of the ICCM processing unit 24 of the management card MC and the ICCM processing unit 40 of the line card LC is periodically (every period Tc (for example, 1 ms)) an ICCM frame (internal communication monitoring frame). ).

  Here, the MC ERP control unit 22 (specifically, the VID filter control requesting unit 25) of the management card MC always sends a ring port open command or block command to the ICCM frame transmitted to the line card LC. Is stored. On the other hand, the LC ERP control unit 32 (specifically, the port control unit 42) of the line card LC always stores open / close information of the ring port of the own card in the ICCM frame transmitted to the management card MC. . The opening / closing information of the ring port is held in, for example, the port management table 43 in FIG.

  Specifically, as shown in FIG. 18A, the ICCM frame includes regions 50 to 53. The area 50 stores a destination card ID, and the area 51 stores a transmission source card ID. The area 52 stores a flag for notifying the aforementioned RDI state (a flag for notifying the other party that the LOC state has been detected). The area 53 has N bits when the maximum number of ports included in one line card LC is N, for example.

  Then, as shown in FIG. 18B, in the ICCM frame transmitted from the management card MC to the line card LC, each bit in the area 53 has a corresponding port blocking command or Represents an open command. On the contrary, in the ICCM frame transmitted from the line card LC to the management card MC, each bit in the area 53 is notified that the corresponding port is in the blocked state BK or in the open state OP according to the logical value. It represents the notification of being.

  In FIG. 17, the MC ERP control unit 22 of the management card MC sets the ICCM frame region 53 (corresponding to this) while the ring port is set to the open state OP based on the ring protocol. The release command is stored in the bit). On the other hand, the LC ERP control unit 32 of the line card LC maintains the open state OP of the ring port in response to the release command, and the area 53 (the corresponding bit) of the ICCM frame transmitted to the management card MC Is stored in the open state notification.

  On the other hand, when the MC ERP control unit 22 of the management card MC changes the ring port from the open state OP to the closed state BK based on the ring protocol, the area of the ICCM frame transmitted to the line card LC thereafter. The block instruction is stored in 53 (the corresponding bit) (step S304). On the other hand, the LC ERP control unit 32 of the line card LC changes the ring port from the open state OP to the closed state BK in response to the block command (step S400), and then the ICCM transmitted toward the management card MC. The block state notification is stored in the frame area 53 (the corresponding bit) (step S401).

  The MC ERP control unit 22 (specifically, the R-APS generation unit 26) refers to the information on the region 53 (ring port opening / closing information) included in the ICCM frame from the line card LC. It is determined whether or not a blockage completion notification is received in step S305. Specifically, the R-APS generation unit 26 recognizes that the blockage state notification is stored in the corresponding bit of the area 53, and determines whether or not the blockage completion notification has been received. In response to this, the R-APS generator 26 transmits an R-APS frame to the line card LC (step S306).

  For example, when the method shown in FIG. 16 is used, since the interrupt process triggered by the change is used, the ring protocol operation can be performed at high speed. However, in this case, the ICCM processing units 24 and 40 need to include a circuit for transmitting by an interrupt in addition to a circuit for periodically transmitting the ICCM frame. On the other hand, when the method of FIG. 17 is used, the speed of the ring protocol operation depends on the transmission interval of the ICCM frame, but the interrupt circuit as in the case of FIG. Can do. Further, since the ring port opening / closing command and the notification of the opening / closing information are periodically issued, it is possible to prevent a command omission and a notification omission due to an unexpected situation.

  As described above, by using the relay device and the relay system according to the present embodiment, it is typically possible to prevent the occurrence of a loop route in the ring network.

  As mentioned above, the invention made by the present inventor has been specifically described based on the embodiments. However, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the invention. For example, the above-described embodiment has been described in detail for easy understanding of the present invention, and is not necessarily limited to one having all the configurations described. Further, a part of the configuration of one embodiment can be replaced with the configuration of another embodiment, and the configuration of another embodiment can be added to the configuration of one embodiment. . In addition, it is possible to add, delete, and replace other configurations for a part of the configuration of each embodiment.

  For example, here, as a ring protocol of the relay system, ITU-TG Although the case where the ring protocol defined in 8032 is used is taken as an example, the present invention is not necessarily limited to this, and even when other ring protocols are used, the same effect can be obtained by applying the same. There is. Although a chassis type relay device is used here, a box type relay device may be used in some cases.

DESCRIPTION OF SYMBOLS 10 Ring network 20 Fabric path | route part 22 MC ERP control part 24,40 ICCM process part 25 VID filter control request part 26 R-APS production | generation part 32 LC ERP control part 36 VID filter 41 R-APS relay part 42 Port control part 43 Port management table 45 Ring management table BK Blocked state LC, LC [1] to LC [n] Line card MC management card OP Open state Pr, Pr [1], Pr [2] Ring port SWa to SWd Relay device

Claims (8)

A line card with a ring port connected to the ring network;
A management card for managing the line card;
A relay device having
The management card is
A port control request unit that determines to change the ring port from an open state to a blocked state in response to an event based on a ring protocol, and issues a ring port blocking command to the line card;
A control frame generating unit that generates a control frame based on the ring protocol and transmits the control frame to the line card;
With
The line card is
A port control unit that controls the ring port in the blocked state in response to the block command from the management card, and issues a block completion notification to the management card after completing the control to the blocked state;
A control frame relay unit for transmitting the control frame from the management card from the ring port;
With
The control frame generation unit of the management card transmits the control frame to the line card after receiving the closure completion notification.
Relay device. The relay device according to claim 1,
The port control request unit of the management card determines to change the ring port from the blocked state to the opened state in response to an event based on the ring protocol, and the control frame generation unit transmits the control frame. After stopping, issue the ring port release command to the line card,
The port controller of the line card controls the ring port to the open state in response to the open command from the management card.
Relay device. The relay device according to claim 1 or 2,
Each of the management card and the line card includes an internal communication monitoring unit that monitors communication with a partner by periodically communicating with each other through an internal communication monitoring frame.
The port control unit of the line card stores the opening / closing information of the ring port in the internal communication monitoring frame transmitted toward the management card,
The control frame generation unit of the management card determines whether or not the blockage completion notification is received by referring to the opening / closing information of the ring port included in the internal communication monitoring frame from the line card.
Relay device. The relay device according to claim 1 or 2,
The ring protocol is ITU-T G.264. A ring protocol defined in 8032.
Relay device. A relay system comprising a plurality of relay devices constituting a ring network,
At least one of the plurality of relay devices is
A line card comprising a ring port connected to the ring network;
A management card for managing the line card;
Have
The management card is
A port control request unit that determines to change the ring port from an open state to a blocked state in response to an event based on a ring protocol, and issues a ring port blocking command to the line card;
A control frame generating unit that generates a control frame based on the ring protocol and transmits the control frame to the line card;
With
The line card is
A port control unit that controls the ring port in the blocked state in response to the block command from the management card, and issues a block completion notification to the management card after completing the control to the blocked state;
A control frame relay unit for transmitting the control frame from the management card from the ring port;
With
The control frame generation unit of the management card transmits the control frame to the line card after receiving the closure completion notification.
Relay system. The relay system according to claim 5, wherein
The port control request unit of the management card determines to change the ring port from the blocked state to the opened state in response to an event based on the ring protocol, and the control frame generation unit transmits the control frame. After stopping, issue the ring port release command to the line card,
The port controller of the line card controls the ring port to the open state in response to the open command from the management card.
Relay system. The relay system according to claim 5 or 6,
Each of the management card and the line card includes an internal communication monitoring unit that monitors communication with a partner by periodically communicating with each other through an internal communication monitoring frame.
The port control unit of the line card stores the opening / closing information of the ring port in the internal communication monitoring frame transmitted toward the management card,
The control frame generation unit of the management card determines whether or not the blockage completion notification is received by referring to the opening / closing information of the ring port included in the internal communication monitoring frame from the line card.
Relay system. The relay system according to claim 5 or 6,
The ring protocol is ITU-T G.264. A ring protocol defined in 8032.
Relay system.

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