JP2015201687A - Network device and synchronization control method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce a time required to synchronize application data between a synchronization source active module and a module that should be synchronized.SOLUTION: In a network device 1, a mounted active module 100 comprises: transmission means 102 that transmits a synchronization packet transmitted by an application to a standby module 200 via a communication cable 300; and synchronization control means 101. The synchronization control means 101 comprises: identification number giving means 111 that gives the synchronization packet an identification number of the application; sequence number adding means 112 that gives the synchronization packet a sequence number; transmitted sequence number registration means 120 that registers the sequence number of the synchronization packet stored in the transmission means 102; and number checking means 130 that receives the sequence number of a synchronization packet arriving at the standby module 200, checks the arriving sequence number with the transmitted sequence number, and confirms arrival of the synchronization packet.

Description

  The present invention relates to a network device. In particular, the network device module is divided into an active system and a standby system, and a plurality of modules are mounted on the device, and information held by the active system module is reserved in case the active system fails. Synchronous control method for synchronizing to the active module, and the information held by the active module installed in the active network apparatus by installing two network devices separately for the active system and the standby system The present invention relates to a synchronization control method for synchronizing with an active module mounted on a network device.

  Conventionally, a network device such as a router or a LAN (Local Area Network) switch has, for example, a forwarding engine which is hardware responsible for packet transfer, a control engine equipped with software for controlling the forwarding engine, and a power source. Etc. A network device is known in which a forwarding engine and a control engine are modularized and an active module and a standby module are mounted to make the module redundant (see Non-Patent Document 1).

  In the technology described in Non-Patent Document 1, data of software (hereinafter referred to as application application) for controlling the forwarding engine is synchronized between two modules in a redundant network device, and switching at the time of failure, etc. In preparation. In this method, in preparation for switching, the network device transmits information held by the active system module to the standby system module using, for example, an Ethernet (registered trademark) communication cable. As a result, the application data held in the standby module is synchronized with the application data held in the active module. Here, since the standby system module is the side where data is updated, it corresponds to the synchronized module for the active system module.

Takehisa Hayashi, Shinji Nozaki, “The Forefront of Router Development, 7th Countermeasure for Router Duplication [1] Synchronize Information while Maintaining Processing Performance”, June 3, 2008, [online], [ Search on July 26, 2013], Internet <URL: http://itpro.nikkeibp.co.jp/article/COLUMN/20080529/305018/?ST=network>

  In an IP network, there are applications that require a low delay according to services and applications that allow a slight delay. For example, data of a plurality of applications may be synchronized between two modules of the network device at the same time. On the other hand, in the conventional technology, in the synchronization source active module, each application performs a process of individually synchronizing each synchronization data (synchronization packet), and a plurality of applications share a single route. Even applications that require low latency are not prioritized over other applications, and time is required to synchronize their data.

  Further, when the communication path (synchronization path) between the two modules to be synchronized is disconnected, a difference occurs in the synchronization data between the two modules. On the other hand, in the prior art, since it was not known how far the application synchronization was completed, it was necessary to transmit all synchronization data of all applications to be synchronized in the synchronization-source active module to the synchronized module. Therefore, the synchronous data transmission at the time of session recovery cannot be accelerated, and it takes time for the recovery.

The present invention has been made in view of such a background, and the present invention provides a network device that reduces the time required to synchronize application data between a synchronization-source active module and a synchronized module. The task is to do.
It is another object of the present invention to provide a synchronization control method that reduces the time required to synchronize application data between a synchronization-source active module and a synchronized module.

  In order to solve the above-described problems, a network device according to the present invention is a network device in which a working module and a standby module on which a plurality of applications operate in an IP network is mounted, and information held by the working module Is a network device that synchronizes with a synchronized module that represents a working module installed in a standby system module and another network apparatus, and the working module that is the synchronization source synchronizes within the module Aggregates the data of a plurality of necessary applications, receives a synchronization packet transmitted from each application for data synchronization, adds information for synchronization to the synchronization packet, and sends the synchronization packet to the synchronized module Synchronous control that controls the transfer And a transmission means for transferring the synchronization packet with information for synchronization to the synchronized module via a communication cable, and the synchronization control means sends the synchronization packets in a predetermined order for each application. An identification number giving means for giving an application-specific identification number for processing to the synchronization packet; and a sequence number giving means for giving a sequence number to the synchronization packet for each application identification number given to the synchronization packet; The sequence number of the synchronization packet that has arrived is notified from the transmitted sequence number registration means that registers the sequence number of the synchronization packet stored in the transmission means as the transmitted sequence number for each application identification number, and the synchronized module. Sometimes the notified sequence number and sent A number verification means for verifying the arrival of the synchronization packet by comparing the sequence number with each application identification number, and the synchronized module is added to the synchronization packet received from the active module of the synchronization source. A sequence number acquisition unit that acquires a sequence number for each application identification number; a sequence number registration unit that registers a sequence number acquired from a received synchronization packet as a sequence number for each application identification number; And arrival number notification means for notifying the active module of the reached sequence number for each application identification number.

  According to such a configuration, the network device aggregates data of a plurality of applications that need to be synchronized in the synchronization source active module, and assigns an application-specific identification number to the synchronization packet. Can be preferentially synchronized. In addition, since the network device assigns a sequence number to the synchronization packet to which the application-specific identification number is assigned and transmits it from the synchronization source active module to the synchronized module, when the communication session of the synchronization path is disconnected, From the reached sequence number, it can be confirmed how far synchronization has been achieved.

  In order to solve the above-described problem, the synchronization control method according to the present invention is a network device in which a working module and a standby module on which a plurality of applications operate in an IP network is mounted. Is a synchronization control method in a network device that synchronizes with a synchronized module that represents a standby system module and a working module installed in another network apparatus, and in the synchronization source working module An identification number assigning step for assigning an application-specific identification number to the synchronization packet for processing the synchronization packet transmitted by the application for data synchronization in a predetermined order for each application; Application For each identification number, a sequence number assigning step for assigning a sequence number to the synchronization packet, a storage step for storing the synchronization packet in the transmission means, and a sequence number of the synchronization packet stored in the transmission means as a transmitted sequence number As a registered sequence number registration step for each application identification number, and a transmission step for transmitting the synchronization packet stored in the transmission means to the synchronized module via the communication cable. A reception step of receiving a synchronization packet from the active module of the synchronization source, a transfer step of transferring the synchronization packet to the application based on the application identification number assigned to the received synchronization packet, and the received synchronization packet She has been granted A reached sequence number registration step for registering each service identification number as an reached sequence number for each application identification number, and an arrival number notification step for notifying the active module of the reached sequence number for each application identification number. The synchronization source active module has a number verification step for verifying the arrival of the synchronization packet by verifying the sequence number notified from the synchronized module and the transmitted sequence number for each identification number of the application. Features.

  According to this procedure, the synchronization control method assigns an application-specific identification number to the synchronization packet in the synchronization source active module of the network device, so that an application requiring low delay can be preferentially synchronized. In addition, the synchronization control method assigns a sequence number to a synchronization packet to which an application-specific identification number is assigned and transmits it from the synchronization source active module to the synchronized module by the transmission means. In this case, it is possible to confirm how far synchronization has been achieved from the reached sequence number.

  According to the present invention, it is possible to reduce the time required to synchronize application data between a synchronization-source active module and a synchronized module.

1 is a block diagram schematically showing a network device according to a first embodiment of the present invention. It is a sequence diagram which shows typically the synchronous process in the network device which concerns on 1st Embodiment of this invention. It is a block diagram showing typically a specific example of a network device concerning a 1st embodiment of the present invention. It is a sequence diagram which shows typically the synchronous process by the active system module of FIG. It is a block diagram which shows typically the network device which concerns on 2nd Embodiment of this invention. It is a sequence diagram which shows typically the synchronous process in the network device which concerns on 2nd Embodiment of this invention. It is a block diagram which shows typically the network device which concerns on 3rd Embodiment of this invention. It is a sequence diagram which shows typically the synchronous process in the network device which concerns on 3rd Embodiment of this invention. It is a block diagram which shows typically the network device which concerns on 4th Embodiment of this invention. It is a sequence diagram which shows typically the synchronous process in the network device which concerns on 4th Embodiment of this invention. 1 is a block diagram schematically showing a redundant network device according to the present invention. FIG. It is a block diagram which shows the conventional network device typically.

In the network device according to the present invention, a module is divided into an active system and a standby system, and a plurality of modules are mounted on the apparatus. The information held by the active system module is synchronized with the standby system module, and two network devices are used. The system is installed separately from the system and the standby system, and the information held in the active system module mounted on the active network apparatus is synchronized with the active system module mounted on the standby network apparatus. In other words, the synchronized modules that synchronize the stored information with the active module of the synchronization source include the standby module installed in the network apparatus of the synchronization source and the active module installed in the other network apparatus. Exists. However, in order to simplify the description, in each of the following embodiments, it is assumed that a synchronized module indicating a module whose data is to be updated is a standby module mounted in a synchronization source network device. Hereinafter, a network device and a synchronization control method of the present invention will be described in detail with reference to the drawings.
(First embodiment)
The network device 1 shown in FIG. 1 is, for example, a router or a LAN switch. The network device 1 includes an active module 100 and a standby module (synchronized module) 200. The network device 1 synchronizes the information held by the active module 100 with the standby module 200 via the communication cable 300 in the device.

  In the active module 100, a plurality of applications 104 operate. Here, the active module 100 includes two applications 104 (application names: A-1, A-2) related to each other in order to provide a predetermined service (hereinafter referred to as service A). The active module 100 includes two applications 104 (application names: B-1, B-2) associated with each other in order to provide another service (hereinafter referred to as service B).

  The standby module 200 includes a plurality of applications 204 similar to those operating on the active module 100, and each application 204 operates when switching due to a failure of the active module 100 or the like.

  Since the network device 1 is the same as the related art except for the components related to the application synchronization processing, the description and illustration will be appropriately omitted below. When the network device 1 is, for example, a layer 3 switch, as shown in Non-Patent Document 1, a control engine equipped with a forwarding engine that is hardware responsible for packet forwarding and software that controls the forwarding engine is provided. It consists of an engine and a power supply. Here, for example, two control engines correspond to the active module 100 and the standby module 200 shown in FIG. In the case of a control engine, for example, a configuration table, an ARP (Address Resolution Protocol) / NDP (Neighbor Discovery Protocol) table, various protocol information, and hardware control information are stored as information to be synchronized.

As shown in FIG. 1, the active module 100 includes a synchronization control unit 101 and a transmission unit 102 as a configuration for transmitting synchronization data to the standby module 200.
The synchronization control unit 101 aggregates data of a plurality of applications 104 that need to be synchronized in the active module 100 and receives packets (synchronization packets) transmitted from each application 104 for data synchronization. Control for adding synchronization information to the synchronization packet and transferring the synchronization packet is performed.

  In this example, the synchronization control unit 101 aggregates two applications 104 that provide the service A and handles them as an application group 103 (application group name: A), and aggregates the two applications 104 that provide the service B to collect applications. It is handled as a group 103 (application group name: B). The standby module 200 includes a plurality of application groups 203 similar to those operating on the active module 100, and each application group 203 operates when switching due to a failure of the active module 100 or the like.

In the present embodiment, the synchronization control unit 101 includes a packet transfer control unit 110, a transmitted sequence number registration unit 120, and a number verification unit 130.
The packet transfer control unit 110 includes an identification number giving unit 111 and a sequence number giving unit 112.
The identification number giving means 111 gives an application-specific identification number to the synchronization packet for processing the synchronization packet in a predetermined order for each application. The identification number assigning unit 111 assigns an application identification number in the synchronization packet transmitted by each application 104 of the active module 100.

  The sequence number assigning unit 112 assigns a sequence number to the synchronization packet for each application identification number assigned to the synchronization packet. The packet data of the synchronization packet to which the application identification number and sequence number are assigned is stored in the transmission means 102. For the synchronization packet in which the packet data is stored in the transmission means 102, the sequence number information assigned to the synchronization packet by the sequence number assignment means 112 is output to the transmitted sequence number registration means 120 together with the application identification number information. The

  The transmitted sequence number registration unit 120 registers the sequence number of the synchronization packet stored in the transmission unit 102 as a transmitted sequence number for each application identification number.

  The number collating unit 130 collates the notified sequence number with the transmitted sequence number for each application identification number when the standby module 200 is notified of the sequence number of the arrived synchronization packet. Confirming the arrival of

  The transmission unit 102 transfers the synchronization packet to which the application identification number and sequence number (information for synchronization) are assigned to the standby module 200 via the communication cable 300. The transmission means 102 is composed of a predetermined transmission interface, and outputs the synchronization packet stored in the transmission queue to the communication cable 300. The transmission unit 102 sequentially outputs packet data held in a first-in first-out list structure in the transmission queue.

The standby system module 200 includes synchronization control means 201 as a configuration for receiving synchronization data from the active system module 100.
The synchronization control unit 201 includes a sequence number acquisition unit 210, a reached sequence number registration unit 220, and a reaching number notification unit 230.

  The sequence number acquisition unit 210 acquires the sequence number assigned to the synchronization packet received from the active module 100 for each application identification number. The acquired sequence number is output to the reached sequence number registration means 220 together with the application identification number. The sequence number acquisition unit 210 transfers the synchronization packet to the corresponding application 204 based on the application identification number given to the synchronization packet received from the active module 100.

The reached sequence number registration means 220 registers the sequence number acquired from the received synchronization packet as the reached sequence number for each identification number of the application.
The arrival number notification means 230 notifies the active module 100 of the reached sequence number for each application identification number. The arrival number notification unit 230 notifies the sequence number registered in the reached sequence number registration unit 220.

  A processing flow in the network device 1 and the synchronization control method according to the first embodiment of the present invention will be described with reference to FIG. 2 (refer to FIG. 1 as appropriate). First, in the active module 100, the identification number assigning means 111 assigns an application identification number to the synchronization packet transmitted by the application 104 (step S101: identification number assignment step). Then, the sequence number assigning means 112 assigns a sequence number to the synchronization packet for each application identification number assigned to the synchronization packet (step S102: sequence number assignment step), and sends the synchronization packet to the transmission means 102. (Step S103: storing step). Then, the transmitted sequence number registration means 120 registers the sequence number given to the synchronization packet stored in the transmission queue as the transmitted sequence number for each application identification number (step S104: transmitted sequence number registration step). ). Then, the transmission means 102 transmits the synchronization packet stored in the transmission queue to the standby module 200 via the communication cable 300 (step S105: transmission step).

  Subsequently, in the standby system module 200, the sequence number acquisition unit 210 receives the synchronization packet from the active system module 100 (step S106: reception step), and based on the application identification number given to the received synchronization packet. The synchronization packet is transferred to the corresponding application 204 (step S107: transfer step). Then, the sequence number acquisition unit 210 acquires the sequence number given to the received synchronization packet for each application identification number. As a result, the reached sequence number registration unit 220 registers the sequence number given to the received synchronization packet as the reached sequence number for each application identification number (step S108: reached sequence number registration step). The arrival number notification means 230 notifies the active module 100 of the reached sequence number for each application identification number (step S109: arrival number notification step).

  Subsequently, in the active module 100, the number verification unit 130 verifies the arrival of the synchronization packet by comparing the sequence number notified from the standby system module 200 with the transmitted sequence number for each application identification number ( Step S110: Number collation step). If the reached sequence number and the transmitted sequence number match in the identification number of the predetermined application, the synchronization packet to which the sequence number and the application identification number are assigned is erroneous from the active module 100 to the standby module 200. It was delivered without. After confirming the match, the number verification unit 130 deletes the transmitted sequence number having the same value as the reached sequence number.

  The network device 1 of the present embodiment has the following superior effects than the conventional network device 901 shown in FIG. The conventional network device 901 does not include the synchronization control means 101 and 201 (see FIG. 1) in the active module 902 and the standby module 903. In the active module 902, each application 104 has its own synchronization data. Since the process of individually synchronizing (synchronization packets) was performed, even an application requiring low delay was not prioritized over other applications. On the other hand, the network device 1 according to the present embodiment aggregates data of a plurality of applications 104 that need to be synchronized in the active module 100, handles the data as the application group 103, and assigns an application-specific identification number to the synchronization packet. Therefore, it is possible to preferentially synchronize applications that require low delay.

  Further, when the communication path (synchronization path) between the active module 902 and the standby module 903 is disconnected, the conventional network device 901 does not know how far the application synchronization has been completed at the time of recovery. It was necessary to transmit all synchronization data of all applications to be synchronized in the module 902. On the other hand, the network device 1 according to the present embodiment assigns a sequence number to the synchronization packet to which the application-specific identification number is assigned and transmits the synchronization packet from the active module 100 to the standby module 200. From the completed sequence number, it can be confirmed how far synchronization has been achieved.

(Specific example of priority transfer)
In the first embodiment, priority transfer of a high priority application requiring low delay will be described with reference to FIG. In the network device 1A shown in FIG. 3, the same components as those shown in FIG.

In the network apparatus 1A, an active module 100A and a standby module 200 are mounted. The active module 100A includes synchronization control means 101A. The synchronization control unit 101A includes a packet transfer control unit 110A.
The packet transfer control unit 110A performs control for preferentially transferring a packet having a high priority, and includes an identification number assigning unit 111A, a sequence number assigning unit 112, and a priority determining unit 113.

  The priority determination means 113 determines the priority of the synchronization packet based on the application identification number assigned to the synchronization packet based on the priority tables 113a and 113b registered in advance. In the priority tables 113a and 113b, an application identification number and a priority of the application are associated with each other. In this embodiment, the priority tables 113a and 113b are individually provided for each service. An example of the priority table 113a for service A is shown in Table 1 below, and an example of the priority table 113b for service B is shown in Table 2 below.

  In the example shown in Table 1, in the application group A for realizing the service A, an application whose application name is A-1 (hereinafter simply referred to as application A-1) has a priority of 1, and the application name is It is a high-priority application that requires a lower delay than the application A-2 (application A-2). Note that the lower the priority value, the higher the priority. Similarly, in the example shown in Table 2, in the application group B, the application B-1 is an application having a higher priority than the application B-2. In this example, a packet queue with a high priority and a packet queue with a low priority are prepared as transmission queues of the transmission means 102.

  When assigning an identification number to the synchronization packet received from each application 104 of the active module 100, the identification number assignment unit 111A includes the application group 103 as a unit and the application number 103 in the synchronization packet of the application 104 belonging to the application group 103. An identification number is assigned.

  For example, in the application group A, the identification number 0x01 is assigned in the synchronization packet of the application A-1, and the identification number 0x02 is assigned in the synchronization packet of the application A-2. In the application group B, the identification number 0x01 is assigned in the synchronization packet of the application B-1, and the identification number 0x02 is assigned in the synchronization packet of the application B-2.

  In the synchronization control unit 101A, the packet transfer control unit 110A equally assigns the opportunity to transmit the synchronization packet in units of the application group 103, and gives priority to a packet having a high priority when transmitting the synchronization packet of the application 104 belonging to the application group 103. Control to transfer automatically. Here, for example, the processing is alternately performed in the order of, for example, transferring the synchronization packet of the application A-1 belonging to the application group B after transferring the synchronization packet of the application A-1 belonging to the application group A. In this case, it means that the applications A-1 and B-1 are given priority over the applications A-2 and B-2.

  The flow of processing in the active module 100A of the network device 1A will be described with reference to FIG. 4 (see FIG. 3 as appropriate). The synchronization control unit 101A of the active module 100A presupposes that the priority order for the application identification number is registered in advance in the priority tables 113a and 113b as the priority of the application (step S111: registration step). The application-specific identification number and priority can be set by, for example, the system administrator at the time of initial setting or maintenance of the network device 1A.

  Then, in the synchronization control unit 101A, the identification number giving unit 111A gives the identification number of the application in the synchronization packet of the application 104 belonging to the application group 103, with the application group 103 aggregated in the active module 100 as a unit. (Step S112: Identification number assignment step). Then, the sequence number assigning unit 112 assigns a sequence number to the synchronization packet (step S113: sequence number assigning step).

  Then, in the synchronization control unit 101A, the priority determination unit 113 determines the priority of the synchronization packet based on the identification number of the application given to the synchronization packet based on the priority tables 113a and 113b. A packet having a high degree is preferentially transferred (step S114: priority determination step). That is, the active module 100A determines in which queue to store the packet based on the priority order according to the priority order registered in advance for each application.

  Then, the synchronization control unit 101A assigns the opportunity to transmit the synchronization packet evenly in units of the application group 103, and when transmitting the synchronization packet of the application 104 belonging to the application group 103, a packet having a high priority is preferentially transmitted. (Step S115: storage step). Since the subsequent steps S116 to S119 are the same as steps S104, S105, S109, and S110 shown in FIG. Among these, in the process of step S117, a synchronization packet is transmitted for each priority.

  Specifically, as described in Tables 1 and 2, if the identification number assigned to the packet is 0x01 regardless of the service (or application group), the priority is first, and the identification number assigned to the packet is 0x02. Then, it is assumed that the priority order is registered as being the second priority order. At this time, for example, when processing a total of four types of synchronization packets of applications A-1, A-2, B-1, and B-2, the synchronization packet of application A-1 (first priority) and application B- 1 (the first priority) synchronization packet is alternately transferred. For example, when the transfer of the synchronization data of the application A-1 is completed among the applications A-1 and B-1 being transferred, the remaining synchronization packet of the application A-2 (second priority) and the transfer The synchronous packet of application B-1 in the middle is transferred alternately. Further, when the transfer of the synchronization data of the application B-1 is completed, the synchronization packet of the remaining application A-2 and the synchronization packet of the application B-2 (second priority order) being transferred are alternately transferred.

  According to the network apparatus 1A, since the priority determination unit 113 is provided and the priority of the synchronization packet transmitted from each application 104 in the service (or application group 103) is determined, the priority is stored in the transmission queue of the transmission unit 102. It is possible to synchronize a data synchronization packet of a high priority application requiring low delay with priority over other applications. In addition, an opportunity to transmit a synchronization packet for an application that needs to be synchronized can be fairly assigned to a service (or application group 103) without being biased toward a specific service (or application group 103).

(Second Embodiment)
A network device according to the second embodiment will be described with reference to FIG. In the network device 1B shown in FIG. 5, the same components as those shown in FIG.

  The network device 1B includes an active module 100B and a standby module 200B. The active module 100B includes synchronization control means 101B. The synchronization control unit 101B, when the number verification unit 130B reestablishes the communication session after disconnecting the communication session between the active module 100B and the standby system module 200B in addition to the function of the number verification unit 130 shown in FIG. The standby system module 200B has a function of inquiring the reached sequence number.

  When the communication session is re-established, if there is a difference between the sequence number notified by the inquiry and the transmitted sequence number, the number verification unit 130B transmits to the application 104 corresponding to the identification number of the application. Request all necessary synchronization data. In FIG. 5, the case where the number matching unit 130B requests the synchronization data from the application A-2 is schematically shown by a broken line as an example.

  When the communication session is re-established, the packet transfer control unit 110 of the synchronization control unit 101B receives an application identification number for each synchronization packet of all the data received from the application 104 for which all the synchronization data is requested from the number verification unit 130B. In addition, a control for re-sending the synchronization packet by assigning the sequence number again is performed.

  The standby system module 200B includes synchronization control means 201B. In addition to the function of the arrival number notification unit 230 shown in FIG. 1, the synchronization control unit 201B accepts an inquiry from the active module 100B when the communication session is reestablished, and sets the reached sequence number. It has a function to notify.

  With reference to FIG. 6 (refer to FIG. 5 as appropriate), the flow of processing when the communication session between the active module 100B and the standby module 200B is disconnected in the network apparatus 1B will be described. First, a communication session such as a TCP session on a synchronous path is established between the active module 100B and the standby module 200B (step S121: communication session establishment). Then, it is assumed that the communication session is disconnected due to detection of a KeepAlive timeout or a state abnormality (step S122: communication session disconnection). In this case, the communication session on the synchronization path is reestablished between the active module 100B and the standby module 200B (step S123: communication session reestablishment).

  Under the above assumption, the active module 100B and the standby module 200B perform the following exchanges. That is, first, in the active system module 100B, the number verification unit 130B inquires the standby sequence number of each application to the standby system module 200B (step S124). Thereby, in the standby system module 200B, the arrival number notification means 230B notifies the arrival sequence number to the active system module 100B (step S125).

  In the active module 100B, the number matching unit 130B extracts the identification number of the application having a difference between the transmitted sequence number and the reached sequence number (step S126). The number verification unit 130B requests the application 104 having a difference in step S126 to transmit all the synchronization packets (all the synchronization data) of the synchronization data (step S127). As a result, the packet transfer control unit 110 of the synchronization control unit 101B gives the retransmission by giving the application identification number and sequence number to the synchronization packet received from the application 104, and the transmission unit 102 The synchronization packet is retransmitted to the module 200B (step S128).

  According to the network device 1B, when the communication session on the synchronization path between the two modules is disconnected, the difference in synchronization data generated between the active module 100B and the standby module 200B when the communication session is reestablished. All synchronization data for the corresponding application 104 is retransmitted from the active module 100B. Therefore, in addition to relieving packet loss due to communication session disconnection, it is necessary to restore synchronization data by specifying a range to synchronize so that only applications with differences in specific synchronization data, not all applications, are synchronized. Time can be shortened compared with the past.

(Third embodiment)
A network device according to the third embodiment will be described with reference to FIG. In the network device 1C shown in FIG. 7, the same components as those shown in FIG.

  The network device 1C includes an active module 100C and a standby module 200C. The active module 100C includes synchronization control means 101C. The synchronization control unit 101C includes a packet transfer control unit 110C, a transmitted sequence number registration unit 120, a number verification unit 130C, and a cache unit 150.

The cache means 150 temporarily stores packet data of the synchronization packet including the application identification number and sequence number of the synchronization packet.
In the present embodiment, when the active module 100C transmits synchronization data, the transmitted packet to which the sequence number is assigned is cached for each application identification number. For example, when processing a total of four types of synchronization packets of applications A-1, A-2, B-1, and B-2, the cache unit 150 includes an A-1 cache unit 151 and an A-2 cache unit 152. And a B-1 cache unit 153 and a B-2 cache unit 154.

  In addition to the function of the number verification unit 130 shown in FIG. 1, the number verification unit 130C is configured so that the standby system module 200C when the communication session is reestablished after the communication session between the active system module 100C and the standby system module 200C is disconnected. Has a function to query the reached sequence number. If there is a difference between the sequence number notified by the inquiry and the transmitted sequence number, this number verification means 130C is registered as transmitted in the active module 100C and registered as reached in the standby module 200C. Extract sequence numbers that have not been processed. The extracted sequence number is output to the packet transfer control means 110C together with the application identification number.

  In normal processing, the packet transfer control unit 110C assigns the application identification number and sequence number to the synchronization packet sent from each application 104 and then transfers the packet data to the cache unit 150 when transferring the synchronization packet. Cache. Further, the packet transfer control unit 110C receives the corresponding packet data from the cache unit 150 based on the sequence number extracted by the number verification unit 130C and the identification number of the corresponding application when the communication session is reestablished after disconnection. And control to retransmit the synchronization packet having the selected packet data.

  The standby system module 200C includes synchronization control means 201C. The synchronization control unit 201C receives the inquiry from the active module 100C when the communication session is reestablished in addition to the function of the arrival number notification unit 230C shown in FIG. It has a function to notify.

  The flow of processing when the communication session between the active module 100C and the standby module 200C is disconnected in the network device 1C will be described with reference to FIG. 8 (refer to FIG. 7 as appropriate). In the process shown in FIG. 8, the same steps as those in the process shown in FIG. Steps S121, S122, and S123 are based on the same premise as the process shown in FIG. However, before step S122 (communication session disconnection), in the active module 100C, the packet transfer control unit 110C caches the transmitted synchronization packet to which the sequence number is assigned for each application in the cache unit 150 as a normal process. (Step S131).

  Under the above assumption, the active module 100C and the standby module 200C perform the following exchanges. That is, first, in the active module 100C, the number verification unit 130C inquires the reached sequence number of each application from the standby module 200C (step S124). Thereby, in the standby system module 200C, the arrival number notification means 230C notifies the arrival sequence number to the active system module 100C (step S125).

  In the active module 100C, the number matching unit 130C extracts the identification number of the application having a difference between the transmitted sequence number and the reached sequence number (step S126). Then, the packet transfer control unit 110C selects, from the cache unit 150, a synchronization packet that is not in the reached sequence number among the packets having the transmitted sequence number in the identification number of the application that has a difference in step S126 ( Step S132). Here, among the packets with the transmitted sequence number, the packets not described in the reached sequence number are packets that have not reached the standby system module 200C. Then, the packet transfer control unit 110C stores the selected synchronization packet in the transmission queue, and the transmission unit 102 retransmits the selected synchronization packet (step S133).

  According to the network device 1C, when the communication session on the synchronization path between the two modules is disconnected, the difference in the synchronization data generated between the active module 100C and the standby module 200C when the communication session is reestablished. As the corresponding difference data, the range to be synchronized is designated so that only the difference of the synchronization data in the packet unit is transmitted instead of transmitting all the synchronization data in the application unit. Therefore, it is possible to reduce the time required for recovery of the synchronization data, compared to the case where all the synchronization data is transmitted in units of applications.

(Fourth embodiment)
A network device according to the fourth embodiment will be described with reference to FIG. In the network device 1D shown in FIG. 9, the same components as those shown in FIG.

  The network device 1D includes an active module 100D and a standby module 200. The network device 1D includes an active communication cable 300 and a spare communication cable 310.

  The active module 100D includes synchronization control means 101D. The synchronization control unit 101D establishes in advance a standby synchronization path using the backup communication cable 310, separately from the synchronization path using the current communication cable 300, between the active module 100D and the backup module 200.

The synchronization control unit 101D includes a packet transfer control unit 110D, a transmitted sequence number registration unit 120, and a number verification unit 130D.
The packet transfer control unit 110D normally performs control to transfer the synchronization packet by performing a communication session using session information including the sequence number assigned to the synchronization packet through the synchronization path. When the packet transfer control unit 110D detects the disconnection of the normal synchronization path, the packet transfer control unit 110D takes over the session information used in the synchronization path and performs a communication session using the session information in the backup synchronization path, thereby synchronizing packets. Control to transfer the.

  In addition to the function of the number verification unit 130 shown in FIG. 1, the number verification unit 130D has a function of detecting the disconnection of the communication session due to, for example, a keep-alive timeout or a state abnormality, and detects the disconnection of the communication session. The packet transfer control means 110D is notified. Note that the number verification unit 130D may detect disconnection of the communication session when, for example, the sequence number is not received from the standby module 200 after a predetermined time has elapsed.

  With reference to FIG. 10 (refer to FIG. 9 as appropriate), the flow of processing when the communication session between the active module 100D and the standby module 200 is disconnected in the network apparatus 1D will be described. First, a communication session is established through a normal synchronization path using the communication cable 300 between the active module 100D and the standby module 200 (step S141: communication session establishment). In addition, a communication session is established in advance on a standby synchronization path using the communication cable 310 between the active module 100D and the standby module 200 (step S142: communication session establishment).

  Then, it is assumed that the communication session is disconnected due to the detection of a KeepAlive timeout or a state abnormality (step S143: communication session disconnection). In this case, the number matching unit 130D detects the disconnection of the normal synchronization path session (step S144). As a result, the packet transfer control unit 110D takes over the application identification number and the TCP sequence number, and resumes the transmission of the synchronization packet using the backup synchronization path (step S145).

  According to the network device 1D, since the communication session between the active module 100D and the standby module 200 is multiplexed, the packet loss due to the disconnection of the communication session of the normal synchronization path is relieved using the backup synchronization path. be able to. In other words, when communication disconnection occurs in the normal synchronization path, the synchronization data is not retransmitted after waiting for re-establishment of the communication session, but the session information such as the sequence number of each packet is taken over from the current synchronization path and used as a backup. Recovery time can be shortened by continuing communication of synchronous data using a synchronous path.

  As mentioned above, although each embodiment of this invention was described, this invention is not limited to these, It can implement in the range which does not change the meaning. For example, in each embodiment, it has been described that the synchronized module is the standby module 200 mounted in the network device 1 that is the synchronization source. However, the present invention is not limited to this, and the synchronized module includes other modules. The active module 100 mounted on the network device may be used. In this case, in addition to the synchronization control unit 101 and the transmission unit 102, the active module 100 on the side that receives the synchronization data further includes the function of the synchronization control unit 201 (see FIG. 1) for receiving the synchronization data. I have.

  That is, in each of the above embodiments, the active module 100 includes the synchronization control unit 101 and the transmission unit 102 as the configuration for transmitting the synchronization data to the standby system module 200, while the standby system module 200 is the active system module 200. The configuration for receiving the synchronization data from the system module 100 has been described as including the synchronization control unit 201. However, the present invention is not limited to this, and the synchronization control unit 101 and the transmission unit 102 are included in one module. And synchronization control means 201 (for example, sequence number acquisition means 210, reached sequence number registration means 220, and arrival number notification means 230) may be provided. The module configured in this way can be used in common for the active system and the standby system.

  As described above, a redundant configuration including a network device in which a module including the synchronization control unit 101, the transmission unit 102, and the synchronization control unit 201 is allocated to the active system module and the standby system module in one module. This network system is shown in FIG. The redundant network system shown in FIG. 11 includes an active network device 1a and a standby network device 1s. Here, the active network device 1a synchronizes the information held by the active module 100a with the standby module (synchronized module) 200a via the communication cable 300a in the device. 1 corresponds to the network device 1 shown in FIG. Similarly, the standby network device 1s synchronizes the information held by the active module 100s with the standby module (synchronized module) 200s via the communication cable 300s in the device. 1 corresponds to the network device 1 shown in FIG. The active network device 1a can transmit the information held by the active module 100a to the active module (synchronized module) 100s of the standby network device 1s via the communication cable 300e outside the device. it can. In this case, the active module 100s can behave in the same manner as the standby module 200a with respect to the active module 100a. Accordingly, in the same manner as in the above embodiments, the information held by the active module 100a mounted on the active network device 1a can be synchronized with the active module 100s mounted on the standby network device 1s. it can.

1, 1A, 1B, 1C, 1D, 1a, 1s Network device 100, 100A, 100B, 100C, 100D, 100a Active system module 100s Active system module (synchronized module)
101, 101A, 101B, 101C, 101D Synchronization control means 102 Transmission means 103 Application group 104 Application 110, 110A, 110C, 110D Packet transfer control means 111, 111A Identification number assignment means 112 Sequence number assignment means 120 Transmitted sequence number registration means 130, 130B, 130C, 130D Number collating means 113 Priority determining means 113a, 113b Priority table 150 Cache means 200, 200B, 200C, 200a, 200s Standby system module (synchronized module)
201, 201B, 201C Synchronization control means 203 Application group 204 Application 210 Sequence number acquisition means 220 Reached sequence number registration means 230, 230B, 230C Arrival number notification means 300, 300a, 300e, 300s Communication cable

In order to solve the above-described problems, a network device according to the present invention is a network device in which a working module and a standby module on which a plurality of applications operate in an IP network is mounted, and information held by the working module Is a network device that synchronizes with a synchronized module that represents a working module installed in a standby system module and another network apparatus, and the working module that is the synchronization source synchronizes within the module Aggregates the data of a plurality of necessary applications, receives a synchronization packet transmitted from each application for data synchronization, adds information for synchronization to the synchronization packet, and sends the synchronization packet to the synchronized module Synchronous control that controls the transfer And a transmission means for transferring the synchronization packet with information for synchronization to the synchronized module via a communication cable, and the synchronization control means sends the synchronization packets in a predetermined order for each application. An identification number giving means for giving an application-specific identification number for processing to the synchronization packet; and a sequence number giving means for giving a sequence number to the synchronization packet for each application identification number given to the synchronization packet; The priority of the synchronization packet is determined based on the application identification number assigned to the synchronization packet based on a priority table registered in advance in association with the application identification number and the priority of the application. a priority determining unit, Sea synchronization packet stored in the transmission means The registered sequence number is registered for each application identification number as the transmitted sequence number, and when the sequence number of the synchronization packet arrived is notified from the synchronized module, the notified sequence number and the transmission are transmitted. Number verification means for verifying the arrival of the synchronization packet by comparing the completed sequence number for each application identification number, and the synchronized module is attached to the synchronization packet received from the active module of the synchronization source. Sequence number acquisition means for acquiring a sequence number for each application identification number; and a sequence number registration means for registering a sequence number acquired from a received synchronization packet as an arrival sequence number for each application identification number; Application knowledge Possess a reach number notification means for notifying arrival SEQUENCE numbers working system module, the every other number, identification number assigning means, as a unit an application group including a plurality of applications are aggregated, the application belonging to the application group The synchronization control means assigns the opportunity to transmit the synchronization packet evenly for each application group, and the priority of the synchronization packet is transmitted when the synchronization packet of the application belonging to the application group is transmitted. Control is performed to transfer high packets with priority .

In order to solve the above-described problem, the synchronization control method according to the present invention is a network device in which a working module and a standby module on which a plurality of applications operate in an IP network is mounted. Is a synchronization control method in a network device that synchronizes with a synchronized module that represents a standby system module and a working module installed in another network apparatus, and in the synchronization source working module An identification number assigning step for assigning an application-specific identification number to the synchronization packet for processing the synchronization packet transmitted by the application for data synchronization in a predetermined order for each application; Application For each identification number, a sequence number assigning step for assigning a sequence number to the synchronization packet, a storage step for storing the synchronization packet in the transmission means, and a sequence number of the synchronization packet stored in the transmission means as a transmitted sequence number As a registered sequence number registration step for each application identification number, and a transmission step for transmitting the synchronization packet stored in the transmission means to the synchronized module via the communication cable. A reception step of receiving a synchronization packet from the active module of the synchronization source, a transfer step of transferring the synchronization packet to the application based on the application identification number assigned to the received synchronization packet, and the received synchronization packet She has been granted A reached sequence number registration step for registering each service identification number as an reached sequence number for each application identification number, and an arrival number notification step for notifying the active module of the reached sequence number for each application identification number. in synchronization source of the primary system modules, it has a number collation step of checking for a match to arrival of the synchronization packet and a notification sequence number and the transmission sEQUENCE ID from the synchronization module for each identification number of the application, identification The number assigning step assigns an identification number of the application to the synchronization packet of the application belonging to the application group, with the application group consisting of a plurality of applications aggregated in the synchronization source active module as a unit. A registration step for pre-registering the priority order for the application identification number in the priority table as the priority level of the application, and storing it after the sequence number assignment step in the synchronization source active module. Prior to the step, based on the priority table, the priority of the synchronous packet is determined based on the identification number of the application assigned to the synchronous packet, and the priority is determined so that the packet with the higher priority is preferentially transferred. A step, and the storing step assigns the opportunity to transmit the synchronization packet equally for each application group, and when transmitting the synchronization packet of the application belonging to the application group, the packet having a high priority is preferentially stored in the transmission queue. to, characterized in that.

Claims (8)

A network device in which an active module and a standby module for operating a plurality of applications in an IP network are mounted, and information held by the active module is mounted in the mounted standby module and other network devices The network device for synchronizing to the synchronized modules respectively representing the active modules that have been made,
The active module of the synchronization source is
Aggregating data of a plurality of applications that need to be synchronized within the module, receiving synchronization packets transmitted from each application for data synchronization, and adding synchronization information to the synchronization packets Synchronization control means for controlling the synchronization packet to be transferred to the synchronized module;
A transmission means for transferring the synchronization packet to which the information for synchronization is given to the synchronized module via a communication cable;
The synchronization control means includes
An identification number giving means for giving an application-specific identification number to the synchronization packet for processing the synchronization packet in a predetermined order for each application;
Sequence number giving means for giving a sequence number to the synchronization packet for each identification number of the application given to the synchronization packet;
A transmitted sequence number registration unit that registers the sequence number of the synchronization packet stored in the transmission unit as a transmitted sequence number for each identification number of the application;
When the sequence number of the arrived synchronization packet is notified from the synchronized module, the notified sequence number and the transmitted sequence number are collated for each identification number of the application, and the arrival of the synchronization packet is confirmed. A number verification means for checking,
The synchronized module is:
Sequence number acquisition means for acquiring, for each identification number of the application, a sequence number assigned to the synchronization packet received from the synchronization-source active module;
Reached sequence number registration means for registering the sequence number acquired from the received synchronization packet as the reached sequence number for each identification number of the application;
Reaching number notification means for notifying the working module of the reached sequence number for each identification number of the application,
A network device. The synchronization control means includes
Based on the priority table registered in advance in association with the identification number of the application and the priority of the application, the priority of the synchronization packet is determined based on the identification number of the application given to the synchronization packet. A priority determining means for determining,
The identification number assigning unit assigns an identification number of the application in a synchronization packet of the application belonging to the application group in units of the application group including the aggregated applications,
The synchronization control means assigns the opportunity to transmit the synchronization packet evenly in units of the application group, and preferentially transfers the high priority packet when transmitting the synchronization packet of the application belonging to the application group. The network device according to claim 1, wherein control is performed. The number verification means inquires the synchronized module for the reached sequence number when a communication session is reestablished after the communication session between the active module of the synchronization source and the synchronized module is disconnected. When there is a difference between the sequence number notified by the inquiry and the transmitted sequence number, request all data that needs to be transmitted to the application corresponding to the identification number of the application,
The synchronization control means performs control for re-sending the synchronization packet by re-assigning the identification number and the sequence number of the application to each synchronization packet of all data received from the application. Alternatively, the network device according to claim 2. The synchronization control means further comprises cache means for temporarily storing packet data of the synchronization packet including the identification number of the application and the sequence number of the synchronization packet,
The number verification means inquires the synchronized module for the reached sequence number when a communication session is reestablished after the communication session between the active module of the synchronization source and the synchronized module is disconnected. If there is a difference between the reached sequence number notified by the inquiry and the transmitted sequence number, it is registered as transmitted in the active module of the synchronization source and registered as reached in the synchronized module Extract sequence numbers that are not
The synchronization control means performs control for selecting corresponding packet data from the cache means based on the identification number of the corresponding application and the extracted sequence number, and retransmitting the synchronization packet having the selected packet data. The network device according to claim 1, wherein the network device is performed. The network device includes a working communication cable and a spare communication cable as the communication cable,
The synchronization control means includes
In addition to the synchronization path using the working communication cable, a standby synchronization path using the spare communication cable is established in advance between the synchronization-source active module and the synchronized module.
Usually, the synchronization packet is transferred by performing a communication session using session information including the sequence number assigned to the synchronization packet in the synchronization path,
When the disconnection of the synchronization path is detected, control is performed to transfer the synchronization packet by taking over the session information used in the synchronization path and performing a communication session using the session information in the backup synchronization path. Do,
The network device according to claim 1, wherein the network device is a network device. A network device on which an active module and a standby module on which a plurality of applications operate in an IP network are mounted, and information held by the active module is mounted on the mounted standby module and other network devices A synchronization control method in the network device that synchronizes the synchronized modules respectively representing the active modules that have been performed,
In the active module of the synchronization source,
An identification number giving step for giving the synchronization packet an application-specific identification number for processing the synchronization packet transmitted by the application for data synchronization in a predetermined order for each application;
For each application identification number given to the synchronization packet, a sequence number giving step for giving a sequence number to the synchronization packet;
A storage step of storing the synchronization packet in a transmission means;
A transmitted sequence number registration step of registering the sequence number of the synchronization packet stored in the transmission means as a transmitted sequence number for each identification number of the application;
Transmitting the synchronization packet stored in the transmission means to the synchronized module via a communication cable,
In the synchronized module,
Receiving the synchronization packet from the active module of the synchronization source; and
A transfer step of transferring the synchronization packet to a corresponding application based on the identification number of the application given to the received synchronization packet;
A reached sequence number registration step for registering each sequence number assigned to the received synchronization packet as a reached sequence number for each identification number of the application;
A reaching number notifying step for notifying the working module of the reached sequence number for each identification number of the application,
In the synchronization source active module,
A number verification step of verifying arrival of the synchronization packet by comparing the sequence number notified from the synchronized module with the transmitted sequence number for each identification number of the application,
A synchronization control method characterized by the above. The identification number assigning step assigns an identification number of the application in a synchronization packet of the application belonging to the application group in units of an application group composed of a plurality of applications aggregated in the synchronization source active module. ,
Prior to the identification number assigning step, there is a registration step of pre-registering the priority order for the identification number of the application in the priority table as the priority of the application,
In the synchronization source active module,
After the sequence number assigning step and before the storing step, based on the priority table, determine the priority of the sync packet based on the identification number of the application given to the sync packet, A priority determination step for preferentially transferring the high priority packet;
In the storing step, an opportunity to transmit the synchronization packet is equally allocated in units of the application group, and when transmitting the synchronization packet of an application belonging to the application group, the packet having a high priority is preferentially placed in a transmission queue. Store,
The synchronous control method according to claim 6. When the communication session of the synchronization path using the communication cable between the active module of the synchronization source and the synchronized module is disconnected, the arrival sequence number inquired to the synchronized module when the communication session is reestablished Based on the above, at least the synchronization packet corresponding to the difference is retransmitted from the active module of the synchronization source, or a standby synchronization path established in advance between the active module of the synchronization source and the synchronized module is used. Continue transmission of the synchronization packet from the active module of the synchronization source,
The synchronous control method according to claim 6 or 7, characterized in that

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