JP3989447B2 - Communication switching method and data communication apparatus - Google Patents

Description

  The present invention relates to a communication switching method and a data communication apparatus.

  Conventionally, in this type of device, when changing the firmware, for example, when upgrading the program version, the firmware is first read, the device for using this firmware is restarted, and then Firmware update processing is performed, and device startup processing after the update is completed. The device startup is completed. As described above, in order to use the new firmware, it is essential to restart the device. Therefore, communication between the device and the device is completely performed after the device is restarted until the startup is completed. A state of communication interruption that cannot be performed occurs.

  Therefore, two boards equipped with CPU and memory with the same function, for example, a relay function for data relay, are prepared in the device, and one board (working board) is used for normal operation. While the other board (standby board) performs the firmware update process, the firmware update time has been shortened. In this conventional example, when the board is switched from the active system to the standby system after updating the firmware, it is necessary to drop the session with another router once. Further, in the standby system board whose firmware has been changed, the path information and the like learned so far are also lost, so the path information is exchanged between the standby system board and another router (for example, Patent Document 1). ).

JP 2003-258877 A

  However, in the above device, it takes time until the device is in a stable state after the exchange of the route information is completed after the board switching is completed, and a communication interruption state during which no communication can be performed occurs during this time. There was a problem.

  The present invention has been made in view of the above-described problem, and is a communication switching method capable of switching data communication and updating firmware in a state where data communication is possible without causing a communication interruption state. And it aims at providing a data communication apparatus.

  In order to solve the above-described problems and achieve the object, a communication switching method according to the present invention is a data communication apparatus having at least two first and second data communication means, based on path information. In the communication switching method for performing data communication with a data communication device and switching a communication subject of the data communication from the first data communication unit to the second data communication unit in response to a communication switching instruction. An instruction step of outputting a switching instruction, and a transmission step of transmitting information on internal resources necessary for communication to the second data communication unit by the first data communication unit of the communication subject in response to the switching instruction A registration step in which the second data communication means receives the information of the internal resource and registers it in the internal memory; and the information of the registered internal resource And the second data communication means performs data communication with the other data communication device, and each of the data communication means is logically one data communication from the other data communication device. It can be recognized as a means.

  The communication switching method according to the invention of claim 2 further includes a changing step of changing the program of the second data communication means in the above invention, wherein the instruction step includes the switching after the change of the program. An instruction is output.

  The communication switching method according to a third aspect of the invention is characterized in that in the above invention, the communication switching method further includes a granting step of giving identification information to the information of the internal resource transmitted in the transmission step.

  In the communication switching method according to a fourth aspect of the present invention, in the above invention, when the information of the internal resource to which the identification information is assigned is changed in the granting step, the information is given to the information of the internal resource. The transmitted identification information is deleted, and in the transmission step, the information of the internal resource to which identification information is not given is transmitted to the second data communication means.

  According to a fifth aspect of the present invention, there is provided a data communication device comprising at least two first and second data communication means for performing data communication with another data communication device based on path information. The data communication apparatus includes instruction means for instructing switching of the communication. When the data communication means is a communication subject, the data communication apparatus sends information on internal resources to the other data communication according to the instruction for switching of the instruction means. A transmitting means for transmitting to the means; a receiving means for receiving the information on the internal resource transmitted from the other data communication means if the communication subject is not; and the information on the received internal resource is registered in an internal memory. Registration means to perform, external communication means for performing data communication with the other data communication device based on the information of the registered internal resources, Comprising respectively, and wherein the recognizable as a single logical data communication means from said another data communication apparatus.

  According to a sixth aspect of the present invention, there is provided the data communication device according to the above invention, wherein the data communication device further comprises a changing means for changing a program of the data communication means.

  According to a seventh aspect of the present invention, there is provided the data communication device according to the above invention, wherein the registering unit adds identification information to the information of the internal resource transmitted by the transmitting unit.

  Further, in the data communication device according to the invention of claim 8, in the above invention, the registration means deletes the assigned identification information when the information of the internal resource to which the identification information is given is changed. The transmitting unit transmits the information of the internal resource to which the identification information is not given to the other data communication unit.

  The data communication apparatus according to a ninth aspect of the present invention is characterized in that, in the above-mentioned invention, the information of the internal resource includes the route information and information necessary for performing the data communication.

  When a communication switching instruction is input, the communication switching method according to the present invention transmits information on internal resources registered in the first data communication means to the second data communication means, and the second data communication means Since the second data communication unit performs data communication with another data communication device based on the information of the internal resource after the registration is completed, the two data communication units are physically registered. Is logically regarded as one data communication means, and there is an effect that data communication can be switched in a state where data communication is possible without causing a communication disconnection state.

  In the data communication device according to the present invention, in the data communication unit of the transmission subject, the communication unit transmits the information of the internal resource to the other data communication unit in response to the communication switching instruction from the instruction unit. In the data communication unit, the registration unit registers the internal resource information received by the reception unit in the internal memory, and the external communication unit performs data communication with another data communication device based on the internal resource information. Therefore, it is possible to switch data communication in a state in which data communication is possible without causing a communication disconnection state by physically considering two data communication units as one logical data communication unit. There is an effect that can be performed.

  Embodiments of a communication switching method and a data communication apparatus according to the present invention will be described below in detail with reference to the drawings of FIGS. The present invention is not limited to these embodiments, and various modifications can be made without departing from the scope of the present invention.

(Embodiment 1)
FIG. 1 is a system configuration diagram showing an example of a schematic configuration of a data relay system to which a data relay device which is a data communication device according to the present invention is connected. In this figure, in this data relay system, a plurality of routers which are data relay apparatuses using, for example, an OSPF (Open Shortest Path: RFC2328) protocol on a network 1 inside a single autonomous system (AS). 2 and 3 are connected to each other, and these routers 2 and 3 have information on the connection form of the entire network (hereinafter referred to as “topology”). These routers 2 and 3 calculate the optimum route based on this topology information.

  In addition, when the topology changes, the route information is rapidly exchanged between the routers 2 and 3, and the optimum route is always calculated based on the latest topology information. The optimum route information calculated by the router 2 is stored in a forwarding table (not shown) in the route information tables 11 and 21 which are internal memories, and based on the optimum route information, between the routers 2 and 3. IP (Internet Protocol) data is relayed.

  The router 2 is configured to make the OSPF protocol redundant as a safety measure during system operation. For example, as shown in FIG. 1, two routers 10 and 20 that are data communication means configured on different boards A and B, respectively, are physically connected from an external router 3 to one logically. In response to an external communication switching instruction, either one becomes a communication entity and exchanges routing control data (hereinafter referred to as “route information”) with other routers 3 and relays data. Is what you do. Of course, a plurality of other routers 3 may exist on the network.

  This router 2 is, for example, an active system in which the communication operation is in an active state, and includes a router 10 that performs relay processing, and a standby system in which the communication operation is in a standby state and performs relay processing. 20 is connected to another router 3. In this embodiment, for example, the route information received from another router 3 is transferred only to the relay processing unit 12 of the router 10 to reduce the processing load of the entire apparatus. As for the data generated by the router 10, when switching between the active state and the standby state of the communication operation, a session is established between the routers 10 and 20 (boards A and B) by TCP (Transmission Control Protocol), and sequentially. Data transfer 4 is performed, and the board can be switched while maintaining the current state at the time of synchronization.

  Since the routers 10 and 20 have the same configuration, the configuration of the router 10 is representatively shown in the configuration diagram of FIG. 2 here. In FIG. 2, the router 10 includes a path information table 11 that is the internal memory described above, a relay processing unit 12 that is an external communication unit that performs data relay processing, and a version change process that is a change unit that performs version change processing. Unit 13, an external interface 14 connected to another router 3 via the network 1, a transfer processing unit 15 that performs transfer processing of internal resource information, a data change detection unit 16 that detects program changes, and a router The router 2 includes 20 internal interfaces 27 and the internal interface 17, and the router 2 includes the routers 10 and 20 and an operation unit 18 that instructs the routers 10 and 20 to operate. The transfer processing unit 15 constitutes a transmission unit, a reception unit, and a registration unit described in the claims.

  In the route information table 11, in addition to the above-described route information and topology information which are information of internal resources, other internal resource information, for example, information on other routers, sockets (connection information with other routers), Information such as the router ID and the type of route exchanged as a result of the negotiation, information about the own router 10, the route received from the partner router, the filtering setting of the route sent to the partner router, and the router with which the route is exchanged Such information is retained. As shown in FIG. 3, these pieces of information are stored in the route information table 11 as held data in a predetermined unit, and the transfer processing unit 15 adds a flag (*) as identification information to the transferred held data. Thus, it is possible to identify the held data before transfer and the held data that has been transferred.

  The transfer of the internal resources by the transfer processing unit 15 is performed according to a switching instruction transmitted from the operation unit 18 by an operator operating a keyboard or the like, for example, and as a part of a normal router processing operation. Yes. For this reason, the original operation of the router, for example, data relay and exchange of route information are also performed by the relay processing unit 12 as usual. Therefore, since the router 10 also performs protocol processing as a router, the retained data may be updated during the transfer of internal resources. Thus, if there is updated holding data, the data change detection unit 16 detects the updated holding data and deletes the flag of the holding data as shown in FIG. 15 can be transferred again.

  When the transfer processing unit 15 finishes transferring the retained data, which is information on all internal resources, the transfer processing unit 15 disconnects the TCP session between the boards A and B and switches the boards. If, for example, an error message from the router 20 is received during the holding data transfer operation, the transfer processing unit 15 determines that the transfer has failed, and the active holding data remains held. Switching operation is not performed.

  The version change processing unit 13 is a processing unit for performing version change processing of the data relay program of the relay processing unit 12, for example. When changing this version, for example, the operation state is set to the standby state. It is preferable to perform the version upgrade in the state where it has been switched.

  Next, the board switching operation in the router 10 will be described with reference to the flowchart of FIG. In the figure, for example, when the program in the router 20 is upgraded by a version change processing unit in the router 20 in the standby state, the operator switches the board from the router 10 in the active state to the router 20 in the standby state. In this case, the operator operates the operation unit 18 to transmit a switching command to the transfer processing unit 15 via the internal interface 17. By receiving this switching command, the operation of the board switching process by the transfer processing unit 15 is started.

  First, when receiving this switching command, the transfer processing unit 15 establishes a TCP session with the router 20 in the standby state via the internal interfaces 17 and 27 and sets the router 2 in a state where communication within the router 2 is possible. (Step 101). When the TCP session is established, it is determined whether or not to perform a transfer process (step 102). Whether transfer processing is performed between internal interfaces, protocol processing associated with data change, or response processing to an operator's operation (not shown) is determined according to a preset processing priority. Normally, the protocol processing basically has a higher priority than the transfer processing. However, the transfer processing may be prioritized over the protocol processing by scheduling according to the processing status.

  Here, when performing the transfer process, it is determined whether there is information (holding data) of the internal resource to be transferred next in the route information table 11 (step 103). Here, if there is retained data to be transferred, the retained data is read from the route information table 11 and transferred to the router 20 via the internal interfaces 17 and 27 (step 104), and the transferred flag is set as appropriate. (Step 105). Then, it is determined whether or not all the retained data has been transferred (step 106). If there is remaining retained data to be transferred, the process returns to step 102 to determine whether or not to perform the transfer process. When the transfer is finished, the TCP session established with the router 20 is disconnected (step 107), and the above operation is finished. In step 103, even if there is no data to be transferred, the TCP session is disconnected and the above operation is terminated, and the board is switched from board A to board B so that data can be relayed by the upgraded router 20. To do.

  If no transfer processing is performed in step 102, that is, if protocol processing is performed, an update flag is set for the retained data that has been updated in accordance with the data change (step 108). It is determined whether or not there is (step 109).

  If there is no updated holding data, the process returns to step 102 to determine whether to perform transfer processing. If there is updated holding data, the holding data with the update flag set has been transferred. After the flag is deleted (step 110), the retained data is transferred (steps 102 to 104), and the transferred flag is set again (step 105).

  Thus, in this embodiment, when a communication switching instruction is input, the internal resource information is transferred from the active router to the standby router, and when the transfer of all the internal resource information is completed. , By switching boards, it is possible to relay data and exchange route information by a router that was in a standby state without causing a session disconnection, so data communication is possible without causing a communication disconnection state In this state, data communication can be switched and firmware can be updated.

  In this embodiment, the case of switching between the two routers 10 and 20 has been described. However, the present invention is not limited to this, and three or more physically different routers are provided in the router 2, It is also possible to configure these routers so as to be recognized as one router 2 from other routers 3.

1 is a system configuration diagram showing an example of a schematic configuration of a data relay system to which a data relay device that is a data communication device according to the present invention is connected. FIG. It is a block diagram which shows the structure of the router shown in FIG. It is a figure which shows the storage state of the holding | maintenance data in the path | route information table shown in FIG. It is a figure which shows the storage state when the holding | maintenance data in the path | route information table shown in FIG. 3 are changed. 3 is a flowchart for explaining a board switching operation in the router shown in FIG. 2.

Explanation of symbols

1 Network 2, 3, 10, 20 Router 11, 21 Route Information Table 12, 22 Relay Processing Unit 13 Version Change Processing Unit 14 External Interface 15 Transfer Processing Unit 16 Data Change Detection Unit 17, 27 Internal Interface 18 Operation Unit A, B board

Claims (8)

A data communication apparatus having at least two first and second data communication means performs data communication with another data communication apparatus based on the path information, and the communication of the data communication according to a communication switching instruction. In the communication switching method for switching the main body from the first data communication means to the second data communication means,
An instruction step of outputting an instruction to switch the data communication;
In response to the switching instruction, the first data communication means of the communication subject performs route information necessary for communication , topology information, socket information, router ID information, information on what kind of route is exchanged as a result of negotiation A transmission step of transmitting information of internal resources including protocol state transition information, filtering setting information, and neighboring router information indicating which router is performing route exchange to the second data communication unit;
A registration step in which the second data communication means receives the information of the internal resource and registers it in an internal memory;
A communication step in which the second data communication means performs data communication with the other data communication device based on the registered internal resource information;
Each of the data communication means is logically recognizable as one data communication means from the other data communication device. A change step of changing the program of the second data communication means;
The communication switching method according to claim 1, wherein, in the instruction step, the switching instruction is output after the program is changed.   The communication switching method according to claim 1, further comprising a granting step of granting identification information to the internal resource information sent in the sending step. In the granting step, when the information of the internal resource to which the identification information is given is changed, the identification information given to the information of the internal resource is deleted,
4. The communication switching method according to claim 3, wherein, in the transmission step, information on the internal resource to which identification information is not given is transmitted to the second data communication unit. In a data communication apparatus having at least two first and second data communication means for performing data communication with another data communication apparatus based on path information,
Instructing means for instructing switching of the communication,
The data communication means includes
A protocol including path information necessary for communication, topology information, socket information, router ID information, and information on what kind of path exchange is performed as a result of negotiation in response to the switching instruction of the instruction means in the case of a communication subject Transmitting means for transmitting internal resource information including state transition information, filtering setting information, and neighboring router information indicating which router is performing route exchange to the other data communication means;
Receiving means for receiving the information of the internal resource transmitted from the other data communication means when not the communication subject;
Registration means for registering internal resource information received by the receiving means in an internal memory;
External communication means for performing data communication with the other data communication device based on the information of the internal resource registered by the registration means;
The data communication apparatus is characterized in that it can be logically recognized as one data communication means from the other data communication apparatus.   6. The data communication apparatus according to claim 5, further comprising changing means for changing a program of the data communication means.   The data communication apparatus according to claim 5, wherein the registration unit adds identification information to the internal resource information transmitted by the transmission unit. The registration unit deletes the assigned identification information when the information of the internal resource to which the identification information is given is changed,
8. The data communication apparatus according to claim 7, wherein the transmission unit transmits information on the internal resource to which the identification information is not assigned to the other data communication unit.

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