JP2021150693A - Management system of redundant path, and management method of the redundant path - Google Patents

Abstract

To provide a method of detecting a route abnormality of a redundant VLAN in an early period, and achieving an appropriate countermeasure.SOLUTION: A space between PTP hubs 1 and 2 is to be redundant to an A route (V2-M-Aroot; a main route) and a B route (V5-S-Broot; a sub-route) by a LAN duplicate. When a minus state of "Meanpath" of one of the A and B routes is continued, TS"Time Stamp" abnormality is determined. After the determination, the B route is switched to the main route, and the A route is switched to the sub-route.SELECTED DRAWING: Figure 1

Description

The present invention mainly relates to a network redundant in a master-slave route (route) using a communication device conforming to PTP.

PTP (Precision Time Protocol) is a relatively new protocol created to obtain highly accurate time synchronization by limiting the usage environment to LAN, and the specification of PTP is defined as IEEE1588.

In the "PTP", the "Grandmaster (GM)" performs advanced time distribution, and the slave receives the time. In addition, "PTP" realizes a time stamp accuracy of microsecond RMS or less by using the hardware stamp function mounted on the network interface chips "MAC" and "PHY".

Currently, there are two versions of the "PTP" protocol, and "Version 1" provides a "Boundary Lock (BC)" that separates segments for large-scale deployment.

In "Version 2", a switching hub "Transient Clock (TC)" having a delay management function is prepared, which enables more flexible and highly accurate deployment.

A communication device incorporating this PTP function, that is, an L2 (layer 2) switching hub (hereinafter referred to as a PTP hub) is capable of highly accurate time synchronization with GM. In addition, by connecting PTP hubs and exchanging PTP packets between PTP hubs, a master is automatically selected from among the PTP hubs (master selection process), and the time of the selected master's PTP hub is set. The PTP hub becomes a slave and can synchronize the time.

The master PTP hub sends PTP packets to other PTP hubs at regular intervals in order to maintain time synchronization. Further, as an original function, all PTP hubs can notify peripheral devices other than PTP of the state information (PTP information) inside the PTP hub as PTP information packets at regular intervals.

JP-A-2018-174445

The virtual LAN (VLAN) sets a virtual group of terminals in the corporate network (LAN) independently of the physical connection form. Here, using the function of a communication device (hub: HUB) called a LAN switch, grouping is performed according to the protocol to be used such as the MAC address and IP address of the terminal. This has the advantage that the network configuration can be changed regardless of the physical position of the terminal, and there is no need to change the settings even if the terminal is moved.

Then, by using a hub having a redundancy function of VLAN duplication using a PTP VLAN (hereinafter, referred to as a PTP hub), redundancy by VLAN duplication becomes possible. At this time, the PTP hubs have a route switching function for selecting and connecting a route with good conditions within the duplicated route. Patent Document 1 is known as a technique for applying such PTP time synchronization to a virtual LAN.

However, a hub that cannot support VLAN duplication between PTP hubs (a hub that has a PTP function but does not have a VLAN duplication function / a hub that has a VLAN duplication function but the redundancy due to the VLAN duplication assumed here does not work sufficiently) If is present, it may adversely affect the time synchronization process.

In this case, if one route deteriorates sharply, switching to the other route is executed due to redundancy. However, if the time synchronization accuracy between PTP hubs deteriorates or if PTP packets are not forwarded in the middle, it may take a considerable amount of time to switch to another route, or PTP processing for one or both routes may occur. May not be able to be executed.

The present invention has been made to solve such a conventional problem, and an object of the present invention is to detect a redundant VLAN route abnormality at an early stage and take appropriate measures.

(1) One aspect of the present invention is a network management method in which master-slave masters and slaves whose time is synchronized are made redundant in a master-slave path.
The "Meanpath" as the average value of the transmission times of the outward path and the return path between the master and the slave is calculated, and if the calculated negative state of the "Meanpath" continues, it is determined that the time stamp is abnormal.
It is characterized in that the master-slave of the route is switched according to the determination.

(2) Another aspect of the present invention is a method of managing a network in which time-synchronized masters and slaves are made redundant in a master-slave path.
A step of calculating "Meanpath" as an average value of transmission time between the master and the slave on the outward path and the return path, and
If the calculated negative state of "Meanpath" continues, the step of determining that the time stamp is abnormal, and
A step of switching the master-slave of the route according to the determination,
It is characterized by having.

According to the present invention, it is possible to detect a redundant VLAN route abnormality at an early stage and take appropriate measures.

Network configuration diagram showing an example of VLAN duplex connection (normal) of PTP hub, A phase diagram in which an abnormality has occurred in a part of the route shown in FIG. Another network configuration diagram showing a VLAN duplex connection. The state diagram in which the VLAN duplication possible area and the impossible area of the PTP hub are mixed. The flowchart which shows the whole processing of the management method of the redundant path which concerns on embodiment of this invention. The flowchart which shows the detail of S09 in FIG. The flowchart which shows the detail of S10 in FIG. The flowchart which shows the detail of S37 in FIG. The flowchart which shows the detail of S47 in FIG. The flowchart which shows the detail of S28 in FIG. 6 and S39 in FIG.

Hereinafter, the details of the redundant path management method (method) according to the embodiment of the present invention will be described. Here, a network using a plurality of PTP hubs, that is, a network that is redundantly routed by VLAN duplication is assumed, and the occurrence of an abnormality is appropriately dealt with by managing each route.

Explaining with reference to FIG. 1, the PTP hubs 1 and 2 have a route duplicated by the WLANs 1 and 5, the WLAN1 side is referred to as an A route, and the WLAN5 side is referred to as a B route. The PTP hubs 1 and 2 are made redundant by routes A and B, and PTP time synchronization is executed by either route.

At this time, the PTP hub 1 is in the master state, the PTP hub 2 is in the slave state, and the A route is used as the main VLAN (main route), while the B route is operated as the sub VLAN (slave route). In FIG. 1, "V2-M-Alot" indicates the A route as the main route, and "V5-S-Block" indicates the B route as the sub-VLAN.

The main VLAN mainly executes evaluation of route A (hereinafter referred to as evaluation A) by PTP processing and time synchronization. Further, the sub-VLAN mainly executes only the evaluation of the B route by PTP processing (hereinafter, referred to as evaluation B). Here, if the disconnection / evaluation A of the A route becomes worse than the evaluation B and the switching condition is satisfied, the B route is switched to the main VLAN and the A route is switched to the sub VLAN.

Hubs (HUB) A to D interposed between the PTP hubs 1 and 2 have a PTP function, but cannot support VLAN duplication. For example, it cannot be transparent when connecting to "EtoE" / cannot support multiple domains / time stamp (Time Stamp: hereinafter referred to as "TS") processing method is different / only step 2 is supported / with a hub such as a malfunction or failure do.

<< Processing content of redundant route management method (method) >>
(1) Redundancy process when using VLAN Based on FIG. 5, the redundancy process when using VLAN (S01 to S11), which is the main method of managing the redundancy route, will be described. S01 to S8 and S11 during this process are executed by both the master PTP1 and the slave PTP2.
Here, it is assumed that the initial information A to C is set in advance by inputting a command from the user and written in the initial setting file FA1.
A: Information for determining the necessity of changing from multicast to broadcast for each port (hereinafter referred to as BC conversion necessity information D1 of the port).
B: The number of abnormality determinations until the final determination of an abnormality occurs when an abnormality related to time synchronization occurs (hereinafter referred to as the TS abnormality determination number D2).
C: The number of normal judgments until the final judgment is normal at the time of the judgment (hereinafter, the TS normal judgment number D3).
S01, S02: Processing is started by starting PTP hubs 1 and 2. At the start of processing, it is confirmed whether initial settings are required. As a result of this confirmation, the process is terminated if it is not necessary, and if necessary, the information of the port BC conversion necessity information D1, TS abnormality judgment count D2, and TS normal judgment count D3 is read from the initial setting file FA1. It is set (S02).

After that, the processing of the conventional PTP hub is executed, and the PTP hub 1 is elected as the master by the above-mentioned master selection processing, while the PTP hub 2 acts as a slave and synchronizes the time with the PTP hub 1. The processes S03 to S08 and S11 are executed as necessary until the state transitions to either the master state or the slave state. After the state transition to the master / slave, the processes S04 to S11 are executed.

S03: Abnormality counter (counts the number of abnormality determinations) D4, normality counter (counts normality determinations), switching lock flag F1, and other necessary information are initialized.

S04 to S06: In order to confirm whether or not it is necessary to receive not only the original multicast packet but also the broadcast packet, the BC conversion necessity information of the port is confirmed (S04). As a result of the confirmation, if necessary, the process proceeds to S05 to execute the process for receiving the blowcast packet (S05), while if it is not necessary, the process proceeds to S06 to execute the conventional process for receiving the multicast packet (S06).

S07 to S11: As a result of the master selection process, it is confirmed whether or not the master state is set (S07). As a result of the confirmation, if it is in the master state, the process proceeds to S09 to execute the PTP packet transmission process (master).

On the other hand, if it is not in the master state, the process proceeds to S08 to check whether or not it is in the slave state. As a result of the confirmation, if it is in the slave state, the PTP packet transmission process (slave) of S10 is executed.

In the network configuration of FIG. 1, since the PTP hub 1 is in the master state, the PTP packet transmission process of S09 is executed. On the other hand, since the PTP hub 2 is in the slave state, the PTP packet transmission process of S10 is executed. As a result of the confirmation in S08, if it is not in the slave state, the conventional PTP process, that is, the master selection process and the like are executed (S11).

(2) PTP packet transmission processing (master)
The details of the PTP packet transmission process of S09 will be described with reference to FIG. This process is executed by the master PTP hub 1.

S21: When the processing is started, it is confirmed whether or not the received packet P is a PTP processing reset preparation request. As a result of the confirmation, if it is a PTP processing reset preparation request, the process proceeds to S22, while if it is not a PTP process reset preparation request, the process proceeds to S23.

S22: The preparation flag for resetting the PTP processing (PTP processing reset preparation flag F2) is effectively set. Here, "valid = 1" is set in the flag F2, and the process proceeds to S29.

S23: It is confirmed whether or not the received packet P is a PTP processing reset start request. As a result of the confirmation, if it is a PTP processing reset start request, the process proceeds to S24, while if it is not a PTP process reset start request, the process proceeds to S26.

S24: The PTP processing reset preparation flag F2 is confirmed, and if the flag F2 is valid, the process proceeds to S25, while if the flag F2 is invalid, the process proceeds to S29.

S25: The same PTP reset process as before is executed.

S26: For processing other than packet transmission, the conventional PTP processing is executed.

S27 to S29: It is confirmed whether or not the PTP packet can be transmitted (S27). As a result of confirmation, if transmission is possible, the process proceeds to S28.

In S28, the original multicast transmission is converted into a broadcast transmission, and the PTP packet is transmitted from the PTP port. On the other hand, if transmission is not possible, the process proceeds to S29, the conventional PTP timer process is executed, and the process ends after the execution.

(3) PTP packet transmission processing (slave)
The details of the PTP packet transmission process of S10 will be described with reference to FIG. 7. This process is executed by the slave PTP hub 2.

S31 to S36: The same processing as in S21 to S26 is performed.

S37: TS abnormality processing is performed.

S38 to S40: The same processing as in S27 to S29 is performed.

(4) TS Abnormal Processing The TS abnormal processing of S37 will be described with reference to FIG. Here, "Meanpath" is used to determine the occurrence of TS abnormality.

That is, the average value of the transmission time of the outward path and the return path between the master and the slave is called "Meanpath". The value of this "Meanpath" usually does not become negative, but it may occur temporarily depending on the strain. However, if it continues for a long time, it is assumed that some factor that causes a TS abnormality between the PTP hubs 1 and 2 (there may be an abnormality in the TS processing of the PTP hub) has occurred.

Therefore, if left as it is, the time synchronization may gradually shift, a synchronization abnormality may occur after several hours, and a constant deviation may continue. In such a case, it is necessary to switch the route and take an early action on the cause of the abnormality without using the route in which the TS abnormality has occurred.

S41: When the process is started, it is confirmed whether or not a TS abnormality has occurred. Specifically, when "Meanpath" is negative, it is confirmed that a TS abnormality has occurred. As a result of this confirmation, if an abnormality has occurred, the process proceeds to S42, and if no abnormality has occurred, the process proceeds to S48.

S42, S43: First, "1" is added to the abnormality counter D4 (S42). It is confirmed whether or not the numerical value of the abnormality counter D4 after the addition exceeds the number of times of TS abnormality determination D2 (S43). As a result of the confirmation, if it is over, the process proceeds to S44, and if it is not over, the process ends.

S44 to S47: “Valid = 1” is set in the switching lock flag F1 of the route to be determined, that is, the route in which the TS abnormality has occurred among the routes A and B (S44). As a result, the route to be determined is finally determined to have a TS abnormality, and the content of flag F1 "valid = 1" is included in the PTP information packet (transmitted between PTP hubs 1 and 2 at regular intervals). Notify the external device of the occurrence of the TS abnormality by the means of (S45).

In addition, the master of the determination target route, that is, the PTP hub higher than the PTP hub 1, is notified of the reset preparation (S46). After this notification, the master / slave VLAN switching determination process is executed (S47).

S48: Confirm that the switching lock flag F1 is valid / invalid. As a result of confirmation, if it is valid, the process proceeds to S49, and if it is invalid, the process ends.

S49, S50: “1” is added to the normal counter D5 (S49). It is confirmed whether or not the numerical value of the normal counter D5 after the addition exceeds the TS normality determination number D3 (S50). As a result of the confirmation, if it is over, the process proceeds to S51, and if it is not over, the process is terminated as it is.

S51, S52: The abnormality counter D4 and the normal counter D5 are cleared (S51), and "invalid = 0" is set in the switching lock flag (S52). As a result, the route to be determined is finally determined to be normal, and then the processing is terminated.

(5) Master / Slave VLAN Switching Judgment Processing The details of the VLAN switching determination processing of S47 will be described with reference to FIG.

S61: When the processing is started, the A route evaluation value AD and the B route evaluation value BD are acquired based on the information of the switching lock flag F1, the master collection data D6, and the slave collection data D7. At this time, when the information of the switching lock flag F1 is "valid = 1", the evaluation values of both the evaluation values AD and BD are set to "0". This is the minimum evaluation value.

S62: It is confirmed whether or not the A route evaluation value AD is smaller than the route evaluation allowable evaluation value RD. As a result of confirmation, if it is small, the process proceeds to S63, and if it is not small, the process ends. At this time, when the information of the switching lock flag F1 is "valid = 1", the evaluation value is the minimum as described above, so that it is smaller than the allowable evaluation value RD.

S63, S64: The difference of "(B route evaluation value BD on the slave side)-(A route evaluation value AD on the master side)" is calculated (S63). It is confirmed whether or not the difference calculated here is larger than the switching determination threshold value S (S64), and if it is larger, the process proceeds to S65, and if it is not larger, the process ends.

As the threshold value S, for example, if it is assumed that both route evaluation values AD and BD are equivalent, a value of "0" can be used. In this case, if both the A route evaluation value AD and the B route evaluation value BD are the minimum values "0", the processing is terminated without switching the route because the threshold value is not exceeded, while the B route evaluation value is the minimum value "0". If not, the threshold value is exceeded, and the process proceeds to S65.

S65: VLAN-related data of route A on the master side (VLAN information D8, master collection data D6, master collection completion flag F3, etc.) and VLAN-related data of route B on the slave side (VLAN information D8, slave collection data D7, slave) The collection completion flag F4, etc.) is replaced, and then the process ends.

(5) BC conversion transmission processing The details of the BC conversion transmission processing of S28 and S39 will be described with reference to FIG.

S71: When the processing is started, the target PTP port Po is selected in order in order to transmit the PTP packet.

S72: If the selected target PTP port Po is in a normal state in which port transmission is possible, the process proceeds to S73, and if it is not in a normal state, the process proceeds to S77.

S73, S74: With reference to the port BC conversion necessity information D1, it is confirmed whether or not the BC conversion of the selected target PTP port Po is necessary. As a result of the confirmation, if necessary, the process proceeds to S75, and if not necessary, the conventional PTP process is executed (S74) and the process proceeds to S76.

S75, S76: Generate a PTP packet in which the original multicast is changed to broadcast (S75). The generated PTP packet is transmitted from the selected target PTP port Po (S76).

S77: It is confirmed whether or not the processing of S71 to S76 is completed for all of the selected target ports Po. As a result of confirmation, if it is not finished, it returns to S71 and restarts the process, while if it is finished, the BC conversion transmission process is finished.
(6) Action effect According to the redundant route management method, the following effects A to C can be obtained.

A: That is, in a redundant network configuration by duplicating VLAN, it has conventionally required time for route evaluation. On the other hand, according to the redundant route management method, if the "Meanpath" value at the time of time synchronization processing becomes negative a certain number of times, it is detected as a TS abnormality.

Therefore, it is possible to detect the TS abnormality of the main VLAN on the master side at an early stage, quickly switch to the redundant sub-VLAN route on the slave side, and take appropriate measures in this respect. However, since the abnormality detection is performed not only on the main VLAN side but also on the sub-VLAN side (S63), switching is not performed when the evaluation on the sub-VLAN side is low.

B: Further, when there is a hub that cannot support VLAN duplication in the redundant network by VLAN duplication, the regular multicast transmission can be changed to broadcast transmission by the BC conversion transmission processing of S28 and S39. As a result, hubs that cannot support VLAN duplication are passed through, and PTP processing is possible between the PTP hubs 1 and 2 at this point.

C: Further, the BC conversion transmission process can be applied to other than the redundant network configuration by the duplexing of VLAN, and can be used as a workaround when there is a PTP hub to be excluded because it is not managed. The BC conversion transmission process can be used without any problem even in a network configuration in which a hub that supports VLAN duplication and a hub that does not support VLAN duplication are mixed.

<< Example 1 >>
The first embodiment of the redundant path management method will be described with reference to FIG. Here, a problem (change in PTP processing, functional abnormality / failure, etc.) occurs in hub A in the network configuration of the VLAN duplex connection shown in FIG. 1, the "Meanpath" value on the PTP hub 2 side becomes negative, and a TS abnormality occurs. It is assumed that the PTP time synchronization cannot be calculated correctly.

At this time, the PTP hub 2 detects a situation in which the “Meanpath” value is negative as a TS abnormality (S41) and adds it to the abnormality counter D4 (S42). When this situation continues for a certain period of time (time is variable), the value of the abnormality counter D4 exceeds the TS abnormality determination number D2 (S43).

Therefore, the switching lock flag F1 of the A route is set (S44), and the A route evaluation value AD is forcibly lowered to the minimum value “0” (S61). As a result, the A route and the B route are switched on condition that the S62 to S64 are followed.

That is, "V2-M-Alot" (A route) and "V5-S-Block" (B route), "V5-M-Block" (B route) and "V2-S-Alot" (A route). Switch to.

At this time, the PTP information packet is used to notify the outside that a TS abnormality has occurred in the A route (S45, S46). After that, the A route continues to be evaluated by the PTP hub 2, but even if the hub A recovers from the failure, it may return to the master side unless the switching conditions (S61 to S64) such as when the B route is disconnected are satisfied. Can not. As a measure after returning to hub A, it is also possible to restart only PTP hub 1 or PTP hub 2 by remote control.

<< Example 2 >>
The second embodiment of the redundant path management method will be described with reference to FIG. Here, the PTP hubs 1-1 and 1-2 are redundant with a main VLAN (V2-M-Alot) on the master side and a sub VLAN (V5-S-Block) on the slave side.

Further, the PTP hubs 2-1 and 2-2 are redundant with a main VLAN (V3-M-Alot) on the master side and a sub VLAN (V6-S-Block) on the slave side.

At this time, the PTP hubs 1-1 and 1-2 pass through the hubs A and B, while the PTP hubs 2-1 and 2-2 pass through the hubs C and D.

If the hubs A to D are hubs that cannot support VLAN duplication, one / both of the PTP hubs 2-1 and 2 and the PTP hubs 2-1 and 2-2 cannot be connected.

In such a case, if the ports of the PTP hubs 1-1 to 2-2 connected to the hubs A to D are set to BC conversion required (S73), the hubs A to D are transmitted by broadcast, so that PTP processing is performed. Transferred without. As a result, the PTP hub can transmit between the PTP hubs 2-1 and 2-2 and between the PTP hubs 2-1 and 2-2.

<< Example 3 >>
The third embodiment of the redundant path management method will be described with reference to FIG. Here, it is assumed that the PTP hub 1 in the area A is connected to the PTP hubs 2 to 7 belonging to the areas B to E by PTP. At this time, although a PTP hub is used inside the areas A, C, and D, a hub that cannot support redundancy due to VLAN duplication is used for the areas B and E.

According to this network configuration, although PTP connection is normally possible only between areas A and C, BC conversion is performed on the ports of PTP hubs 2 and 4 passing through area B and the ports of PTP hubs 5 and 7 passing through area E. In short (S73), areas A, C, and D are transmitted using regular multicast, while areas B and E are transmitted using broadcast.

Therefore, PTP communication using the PTP hub 1 in the region A as a master is possible between the PTP hub 4 in the region B, the PTP hub 5 in the region C, the PTP hub 6 in the region D, and the PTP hub 7 in the region E. ..

1-7,1-1,1-2,2-1,2-2 ... PTP hubs A to D ... hubs

Claims (7)

It is a network management method in which the master / slave that synchronizes the time is made redundant in the master-slave path.
The "Meanpath" as the average value of the transmission times of the outward path and the return path between the master and the slave is calculated, and if the calculated negative state of the "Meanpath" continues, it is determined that the time stamp is abnormal.
A redundant route management method, characterized in that the master-slave of the route is switched according to the determination. The method for managing a redundant route according to claim 1, wherein when the number of times the "Meanpath" becomes negative exceeds a preset threshold value, it is determined that the time stamp is abnormal. The redundant route management method according to claim 1 or 2, wherein the determination is performed not only on the main route between the master and the slave but also on the slave route. The redundant route management method according to claim 3, wherein if one of the two routes continues to be in the state of abnormality determination, the other route cannot be switched even if the other route is determined to be abnormal. The method for managing a redundant route according to any one of claims 1 to 4, wherein when the abnormality is determined, the abnormality is notified to the outside. The redundant path management method according to any one of claims 1 to 5, wherein a packet required for the time synchronization is transmitted between the master and the slave by bloatcast. It is a network management method in which the master / slave that synchronizes the time is made redundant in the master-slave path.
A step of calculating "Meanpath" as an average value of transmission time between the master and the slave on the outward path and the return path, and
If the calculated negative state of "Meanpath" continues, the step of determining that the time stamp is abnormal, and
A step of switching the master-slave of the route according to the determination,
A method of managing a redundant route, which comprises having.

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