JP3773907B2 - Data relay method, data relay device, and data relay system - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
  The present invention relates to a data relay method, a data relay apparatus and a data relay apparatus using a connection-oriented route exchange protocol capable of ensuring redundancy as a routing control function, for example, BGP (Border Gateway Protocol: RFC1771). YoDeData relay system.
[0002]
[Prior art]
  In a conventional data relay method, as shown in Non-Patent Document 1 of RFC1771, there is a method in which control for exchanging route information between ASs (Autonomous Systems) is performed using this BGP protocol. The AS is a range that is managed and operated by a single management entity under a single route control policy. For example, an ISP (Internet Service Provider) corresponds to this AS.
[0003]
  In this data relay method, as shown in FIGS. 17 to 19, a router 20 of each ISP 11 is connected to the backbone network 10 of the Internet connection service, and a BGP connection called peering is established between these routers 20, After exchanging a routing table (not shown) provided in FIG. 1, IP (Internet Protocol) data is relayed between ISPs 11 based on route information stored in this table. Some of these routers 20 constitute a system by the following two methods as safety measures in the event of a failure. In the following drawings, the same components are denoted by the same reference numerals for convenience of explanation.
[0004]
  The first conventional example is a case where the routing control software program is duplicated. In this case, for example, as shown in FIG. 17, one router (hereinafter referred to as “physical router”) 20 is physically connected. In the data relay operation, logical routers are set to two routers 21 and 22 (hereinafter referred to as “logical routers”), and each of the logical routers performs routing control separately by this redundant routing control software program. Some exchange data (hereinafter referred to as “route information”).
[0005]
  This logical router is in an active state and operates as a logical router (hereinafter referred to as “main router”) 21 that performs main processing, and a logical router that operates in a standby state and performs backup processing (hereinafter referred to as “backup router”). Each logical router is connected to each logical router (or a physical router) of another router via one transmission line 30 via a transmission line 30, and this main router 21 and backup router are connected. Some routers 22 exchange routing control data (hereinafter referred to as “route information”) in a full mesh using the above-described routing control software program.
[0006]
  Further, in the second conventional example, as shown in FIG. 18, for example, when route information is transmitted from one router 20 to the other router 20, the main router of the other router is connected from the communication route for communicating this route information. In some cases, the path information is exchanged by copying and transmitting the path information to the BGP processing units (not shown) of both the backup router 21 and the backup router 22.
[0007]
[Non-Patent Document 1]
          Yakov Rekhter & Tony Li, “RFC1771 A Border Gateway Protocol 4” [online], Internet Official Protocol (STD1), March 1995, p. 1-11, Alter NIC The Network Information Center, [October 1, 2002 search], Internet <URL: "http://www.alternic.org/rfcs/rfc1700/rfc1771.html">
[0008]
[Problems to be solved by the invention]
  However, in the first conventional example, since route information must be exchanged between routers with a full mesh, it is necessary to transmit route information by establishing one connection to one logical router. The number of network traffic increases, transmission traffic on the backbone network by route information transmission increases, and connection management becomes complicated. In the second conventional example, a function for copying and transmitting route information from the logical router is required, so that the implementation is complicated and the processing is large in overhead.
[0009]
  In order to solve such a problem, for example, as shown in the third conventional example of FIG. 19, route reflectors (hereinafter referred to as “aggregation devices”) 23 and 24 for relaying route information are provided on the backbone network 10. The main router 21 and the backup router 22 of each router 20 are connected to the aggregation devices 23 and 24 through the transmission path 31 and exchange the path information via the transmission path 31. Some of these aggregating devices 23 and 24 aggregate received route information, distribute the route information to the main router 21 and the backup router 22 of each router 20, and transmit them.
[0010]
  However, in the third conventional example, the number of path information exchange partners can be reduced, but even in this case, the main router 21 and the backup router 22 need to exchange path information with the aggregation devices 23 and 24, respectively. In addition, there has been a problem that an increase in route information traffic on the backbone network 10 and complicated management are inevitable.
[0011]
  The present invention has been made in view of the above problems, and reduces the number of connections on the backbone network, reduces the route information traffic of the route information, increases the reliability of data relay, and simplifies the system configuration. An object of the present invention is to provide a data relay method, a data relay device, and a data relay system using the device.
[0012]
[Means for Solving the Problems]
  In order to achieve the above object, in the data relay method according to claim 1, a plurality of data relay devices are logically connected.ToAt least two in-process and backup processesMain logical data relay device and subIn the data relay method for relaying data by constructing each logical data relay device,The main logical data relay deviceUsing a connection-oriented communication route exchange protocol for data relay,The other first determined in advance as the connection partner of the own deviceA first connection step for establishing a connection with the data relay device;If the sub logical data relay device receives a survival notification message from the main logical data relay device within a predetermined time, it automatically uses a connection-oriented communication path switching protocol for data relay in advance. To establish a connection with another second data relay device determined as a connection partner of the device, and to perform data relay if no survival notification message is received from the main logical data relay device within a certain time Using the path exchange protocol of connection type communication, the first data relay device determined in advance as the connection partner of the second logical data relay device and the main logical data relay device determined in advance as the connection partner of the own device A second connection step for establishing a connection with the data relay device;The logical data relay device that establishes the connection; andFirst and secondAn exchange step of exchanging the route information with the data relay device ofA synchronization step of synchronizing the exchanged path information between the logical data relay devices set in the data relay device;It is characterized by including.
[0013]
  According to this invention, logicallyMain and sub for main processing and backup processingA data relay method for relaying data between a plurality of data relay devices each having a logical data relay device, wherein each data relay device is different from the data relay device to which one logical data relay device is connected Are connected to each other, and the routing information is exchanged between the connected data relay devices, thereby reducing the number of connections on the backbone network and reducing the routing information traffic of the routing information.At the same time, the route information obtained by each logical data relay device in the data relay device is transferred to the main and sub logical data relays. By synchronizing devices, the shortage of mutual route information due to the reduction in the number of connections is mutually supplemented to share route information..
[0014]
  In the data relay method according to claim 2, the plurality of data relay devices are logically connected.ToAt least two in-process and backup processesMain logical data relay device and subIn the data relay method for relaying data by constructing each logical data relay device,The main logical data relay deviceUsing a connection-oriented communication route exchange protocol for data relay,Predetermined as the connection partner of the deviceA first connection step of establishing a connection with another data relay device via the first data aggregation device;If the sub logical data relay device receives a survival notification message from the main logical data relay device within a predetermined time, it automatically uses a connection-oriented communication path switching protocol for data relay in advance. A connection is established with another data relay device via the second data aggregating device determined as the connection partner of the device, and if there is no reception of a survival notification message from the main logical data relay device within a certain time, Another data relay device and the main logical data are transmitted via the second data aggregating device, which is determined in advance as a connection partner of the own device, using a path switching protocol of connection-type communication for performing data relay. Second to establish a connection with another data relay device via the first data aggregation device determined as a connection partner of the relay device And the connection process,The logical data relay device that establishes the connection; andFirst and secondAn exchange step of exchanging the route information with the data aggregation device ofA synchronization step of synchronizing the exchanged path information between the logical data relay devices set in the data relay device;It is characterized by including.
[0015]
  According to this invention, logicallyMain and sub for main processing and backup processingA data relay method for relaying data between a plurality of data relay devices including the logical data relay device, wherein each data relay device is different from the data aggregator to which one logical data relay device is connected The number of connections on the backbone network is reduced by exchanging path information between the connected logical data relay device and the data aggregation device. Reduce routing information traffic for routing informationAt the same time, the path information obtained by each logical data relay device in the data relay device is synchronized between the main and sub logical data relay devices, resulting in a lack of mutual route information due to the reduction in the number of connections. To share route information with each other.
[0016]
  In the data relay method according to claim 3,In the above invention,Each of the logical data relay devices further includes a selection step of selecting an optimum route based on the route information synchronized in the synchronization step.
[0017]
  According to this invention,Main and subIn each of the logical data relay devices, the mutual route information is supplemented to share the route information, and by selecting the optimum route from the shared route information, an appropriate route such as the shortest route is selected. Enable.
[0018]
  In the data relay method according to claim 4,In the above invention,SaidsubThe logical data relay device ofThe mainA first monitoring step for monitoring whether or not the logical data relay device is operating in the main processing, and in the case where the main processing is not operating,MaineBetween the third connection step of newly establishing a connection with the other data relay device to which the logical data relay device has established a connection and the other data relay device having newly established the connection. And a third exchange step for performing exchange.
[0019]
  According to this invention,subAs part of the backup process, the logical data relay deviceMaineThe main processing operation of the logical data relay device is monitored, and if this main processing is not performed, a new connection is established with another data relay device in place of the active logical data relay device, and the route information Is exchanged to compensate for the harmful effects of reducing the number of connections.
[0020]
  In the data relay method according to claim 5,In the above invention,RecordsubThe logical data relay device of the aboveMaineWhen the operation of the main process by the logical data relay device is resumed, the third connection step further includes a first connection disconnecting step of disconnecting the newly established connection with the other data relay device. It is characterized by that.
[0021]
  According to this invention,MaineBy resuming the main processing operation by the logical data relay device ofsubSince the new connection with the other data relay device by the logical data relay device becomes unnecessary, this connection is cut off to avoid the double connection with the logical data relay device in the same data relay device. To reduce the number of
[0022]
  In the data relay method according to claim 6,In the above invention, the subThe logical data relay device of the aboveMaineWhen the operation of the main process by the logical data relay device is resumed,MaineThe logical data relay apparatus further includes a first output step of outputting the path information acquired while the main processing operation is stopped.
[0023]
  According to this invention,MaineWhen the logical data relay device resumes main processing,subThe logical data relay device of the route information acquired while this operation was stoppedMaineBy sharing the path information, the path information is shared.
[0024]
  In the data relay method according to claim 7,In the above invention,SaidMaineThe logical data relay device of the second monitoring step for monitoring whether the sub logical data relay device is operating in the backup process, and when the backup process is not operating,subBetween the fourth connection step of establishing a new connection with the other data relay apparatus to which the logical data relay apparatus has established a connection and the other data relay apparatus having newly established the connection. And a fourth exchanging step for exchanging.
[0025]
  According to this invention,MaineAs part of the main process, the logical data relay devicesubIf the backup processing operation of the logical data relay device is monitored and this backup processing is not performed,subInstead of the logical data relay device, a new connection is established with another data relay device, and the path information is exchanged to compensate for the adverse effects of reducing the number of connections.
[0026]
  In the data relay method according to claim 8,In the above invention, the mainThe logical data relay device of the abovesubWhen the operation of the backup processing by the logical data relay device is resumed, the third connection step further includes a second connection disconnecting step of disconnecting the newly established connection with the other data relay device. It is characterized by that.
[0027]
  According to this invention,subBy restarting the backup processing operation by the logical data relay device ofMaineSince no new connection with another data relay device is required by the logical data relay device, the number of connections can be avoided by cutting this connection and avoiding double connections with the same data relay device. To reduce
[0028]
  In the data relay method according to claim 9,In the above invention, the mainThe logical data relay device of the abovesubWhen the backup processing operation by the logical data relay device ofsubThe logical data relay apparatus further includes a second output step of outputting the path information acquired while the backup processing operation is stopped.
[0029]
  According to this invention,subWhen the logical data relay device resumes backup processing,MaineThe logical data relay device of the route information acquired while this operation was stoppedsubBy sharing the path information, the path information is shared.
[0030]
  In the data relay device according to the tenth aspect, at least two logically performing main processing and backup processing are performed.Main logical data relay device and subIn a data relay device that is constructed by a logical data relay device, establishes a connection with another data relay device, and relays data of the data.MaineThe logical data relay device ofin frontUse a connection-oriented communication path exchange protocol for data relay,FirstA first connection means for establishing a connection with the data relay device, and a connection is established by the first connection meansThe firstA first exchange means for exchanging the route information with the data relay device, and a first storage means for storing the exchanged route information;First data processing means for performing data processing of route information stored in the first storage means,SaidsubThe logical data relay device ofin frontThe connection type communication path switching protocol for performing data relay is used, and the first connection means establishes a connection.FirstDifferent from the data relay deviceSecondThe second connection means for establishing a connection with the data relay device, and the connection is established by the second connection meansThe secondA second exchange means for exchanging the route information with the data relay device, a second storage means for storing the exchanged route information,Second data processing means for performing data processing of route information stored in the second storage means;WithThe first and second data processing means are exchanged with the first and second data relay apparatuses, and synchronize route information stored in the first and second storage means.It is characterized by.
[0031]
  According to this invention, logicallyMain processing and sub processing for main processing and backup processingA logical data relay device is a data relay device that relays data, for example, IP data, with other data relay devices,Main and subThis logical data relay device uses the first and second connection means to establish a connection with another data relay device different from the data relay device to which one of the logical data relay devices has established a connection. By exchanging, the number of connections on the backbone network is reduced and the route information traffic of the route information is reduced.At the same time, the path information exchanged with the different data relay devices respectively different by the first and second exchanging means is synchronized by the first and second data processing means to share the path information. By further reducing the number of connections on the backbone network, the route information traffic of the route information is reduced..
[0032]
  In the data relay device according to claim 11,In the above invention,Third storage means for storing an optimum route is further provided, and the first and second data processing means select the optimum route based on the synchronized route information, and select the optimum route. The route is stored in the third storage means.
[0033]
  According to the present invention, the first and second data processing means select the optimum route from the shared route information by the algorithm for selecting the route from the synchronized route information, and By storing the data in the storage unit 3, an appropriate route such as the shortest route can be selected.
[0034]
  In the data relay device according to claim 12,In the above invention,SaidsubThe logical data relay device of the aboveMaineA first monitoring unit that monitors a main processing operation of the logical data relay apparatus of the first and second logical units, wherein the second connection unit is connected to the first connection unit according to a monitoring result of the first monitoring unit. The aboveFirstA new connection is established with the data relay device, and the second exchange means establishes a new connection.The firstThe route information is exchanged with the other data relay device.
[0035]
  According to this invention,MaineIf the logical data relay device is not performing the main processing operation,MaineInstead of the logical data relay device, the second connection meanssubBy establishing a new connection between the logical data relay device and another data relay device and exchanging the route information, the disadvantage caused by the shortage of the route information due to the reduced number of connections is compensated.
[0036]
  In the data relay device according to claim 13,In the above invention,The second connection means is based on the monitoring result of the first monitoring means.MaineWhen recognizing that the operation of the main process by the logical data relay device is resumed,FirstThis is characterized in that the newly established connection with the data relay device is disconnected.
[0037]
  According to this invention,MaineBecause the logical data relay device of this re-establishes the connection with the other data relay device that had previously established the connection by resuming the main processing operation,subSince the logical data relay device does not require a connection with the other data relay device, the second connection means disconnects this connection and the same data relay device.AndReduce the number of connections by avoiding double connections.
[0038]
  In the data relay device according to claim 14,In the above invention,The second data processing means is based on the monitoring result of the first monitoring means.MaineWhen recognizing that the operation of the main processing by the logical data relay device is resumed, the path information acquired while the main processing operation is stopped isMaineOutput to the logical data relay device.
[0039]
  According to this invention,MaineIn the data relay device, since the route information is not acquired while the main processing operation is stopped, the second data processing unit obtains the route information acquired while the operation is stopped.subFrom the data relay deviceMaineBy sharing the route information, the route information is shared.
[0040]
  In the data relay device according to claim 15,In the above invention,SaidMaineThe logical data relay device ofThe subFurther comprising second monitoring means for monitoring the backup processing operation of the logical data relay apparatus, wherein the first connection means is the first connection means.2According to the monitoring result of the monitoring means, the second connection means has established a connection.SecondA new connection is established with the data relay device, and the first exchange means establishes a new connection.The secondThe route information is exchanged with the other data relay device.
[0041]
  According to this invention,subIf the logical data relay device is not performing backup processing,subInstead of the logical data relay device, the first connection meansMaineLogical data relay device and otherSecondBy establishing a new connection between the data relay apparatuses and exchanging the path information, the adverse effect caused by the shortage of the path information due to the reduced number of connections is compensated.
[0042]
  In the data relay device according to claim 16,In the above invention,The first connecting means determines the monitoring result of the second monitoring means from the monitoring result.subWhen recognizing that the operation of the backup processing by the logical data relay device is resumed,SecondThis is characterized in that the newly established connection with the data relay device is disconnected.
[0043]
  According to this invention,subBecause the logical data relay device of the above re-establishes the connection with the other data relay device that was previously connected by restarting the backup processing operation,MaineSince the logical data relay device of FIG. 1 does not require a connection with the other data relay device, the first connection means disconnects this connection and the same data relay device.AndReduce the number of connections by avoiding double connections.
[0044]
  In the data relay device according to claim 17,In the above invention,The first data processing means is based on the monitoring result of the second monitoring means.subWhen it is recognized that the operation of the backup processing by the logical data relay device of the above is resumed, the path information acquired during the stop of the backup processing operation issubOutput to the logical data relay device.
[0045]
  According to this invention,subIn the logical data relay apparatus, since the path information is not acquired while the backup processing operation is stopped, the first data processing means uses the path information acquired while the operation is stopped,MaineFrom the logical data relay devicesubBy sharing the path information, the path information is shared.
[0046]
  In the data relay apparatus according to claim 18, at least two logically performing main processing and backup processing are performed.Main logical data relay device and subIn the data relay device that is constructed by the logical data relay device, establishes a connection with the data aggregation device, and relays data of the data,MaineThe logical data relay device ofin frontUse a connection-oriented communication route exchange protocol to relay dataFirstA third connection means for establishing a connection with the data aggregating apparatus, and a connection is established by the third connection meansThe firstA third exchanging means for exchanging the route information with the data aggregating apparatus, a fourth storage means for storing the exchanged route information,Third data processing means for performing data processing of route information stored in the fourth storage means;ComprisingsubThe logical data relay device ofin frontThe connection type communication path exchange protocol for performing data relay is used, and the third connection means establishes a connection.FirstDifferent from the data aggregatorSecondA fourth connection means for establishing a connection with the data aggregating apparatus and a connection established by the fourth connection means;The secondA fourth exchanging means for exchanging the route information with the data aggregating apparatus, and a fifth storage means for storing the exchanged route information;Fourth data processing means for performing data processing of route information stored in the fifth storage means;WithThe third and fourth data processing means synchronize route information exchanged with the first and second data aggregating apparatuses and stored in the fourth and fifth storage means. TakeIt is characterized by.
[0047]
  According to this invention, logicallyMain processing and sub processing for main processing and backup processingA logical data relay device is a data relay device that relays data such as IP data with a data aggregation device,Main and subThe logical data relay apparatus uses the third and fourth connection means to establish a connection with the other data aggregating apparatus different from the data aggregating apparatus to which one of the logical data relay apparatuses has established a connection. By exchanging, the number of connections on the backbone network is reduced and the route information traffic of the route information is reduced.At the same time, the route information exchanged with the different data aggregating devices by the third and fourth exchanging means is synchronized by the third and fourth data processing means to share the route information. Furthermore, by reducing the number of connections on the backbone network, the route information traffic of the route information is reduced..
[0048]
  In the data relay device according to claim 19,In the above invention,Sixth storage means for storing an optimum route is further provided, and the third and fourth data processing means select the optimum route based on the synchronized route information, and select the optimum route. The route is stored in a sixth storage means.
[0049]
  According to the present invention, the third and fourth data processing means select the optimum route from the shared route information by the algorithm for selecting the route from the synchronized route information, and By storing it in the storage means 6, it is possible to select an appropriate route such as the shortest route.
[0050]
  In the data relay device according to claim 20,In the above invention,SaidsubThe logical data relay device of the aboveMaineFurther comprising third monitoring means for monitoring the main processing operation of the logical data relay apparatus, wherein the fourth connection means is connected to the third connection means in accordance with a monitoring result of the third monitoring means. The aboveFirstA new connection is established with the data aggregating apparatus, and the fourth exchange means establishes a new connection.The firstThe path information is exchanged with another data aggregation device.
[0051]
  According to this invention,MaineIf the logical data relay device is not performing the main processing operation,MaineInstead of the logical data relay device, the fourth connection meanssubBy establishing a new connection between the logical data relay device and another data relay device and exchanging route information, the adverse effect of reducing the number of connections is compensated.
[0052]
  In the data relay device according to claim 21,In the above invention,The fourth connection means determines that the monitoring result of the third monitoring means isMaineWhen recognizing that the operation of the main process by the logical data relay device is resumed,First data aggregation deviceIt is characterized by disconnecting the newly established connection.
[0053]
  According to this invention,MaineBecause the logical data relay device of this re-establishes the connection with the other data relay device that had previously established the connection by resuming the main processing operation,subSince the logical data relay device of FIG. 4 does not require a connection with the other data relay device, the fourth connection means disconnects this connection and the same data relay device.AndReduce the number of connections by avoiding double connections.
[0054]
  In the data relay device according to claim 22,In the above invention,The fourth data processing means determines the monitoring result of the third monitoring means from the monitoring result.MaineWhen recognizing that the operation of the main processing by the logical data relay device is resumed, the path information acquired while the main processing operation is stopped isMaineOutput to the logical data relay device.
[0055]
  According to this invention,MaineIn the logical data relay device, since the route information is not acquired while the main processing operation is stopped, the fourth data processing means uses the route information acquired while the operation is stopped.subFrom the logical data relay deviceMaineBy sharing the path information, the path information is shared.
[0056]
  In the data relay device according to claim 23,In the above invention,SaidMaineThe logical data relay device ofThe subAnd a fourth monitoring means for monitoring the backup processing operation of the logical data relay apparatus, wherein the third connection means is connected to the fourth connection means in accordance with a monitoring result of the fourth monitoring means. The aboveSecondA new connection is established with the data aggregating apparatus, and the third exchange means establishes a new connection.The secondThe path information is exchanged with another data aggregation device.
[0057]
  According to this invention,subIf the logical data relay device is not performing backup processing,subInstead of the logical data relay device, the third connection meansMaineLogical data relay device and otherSecond data aggregation deviceBy making a new connection between them and exchanging route information, the adverse effects of reducing the number of connections are compensated.
[0058]
  In the data relay device according to claim 24,In the above invention,The third connection means is based on the monitoring result of the fourth monitoring means.subWhen recognizing that the operation of the backup processing by the logical data relay device is resumed,SecondIt is characterized by disconnecting a newly established connection with the data aggregation device.
[0059]
  According to this invention,subThe logical data relay device of the other has previously established a connection by restarting the backup processing operation.SecondSince the connection with the data relay device is reestablished,MaineSince the logical data relay device of FIG. 3 does not require a connection with another data relay device, the third connection means disconnects this connection and the same data relay device.AndReduce the number of connections by avoiding double connections.
[0060]
  In the data relay device according to claim 25,In the above invention,The third data processing means is configured to obtain the above-mentioned result from the monitoring result of the fourth monitoring means.subWhen it is recognized that the operation of the backup processing by the logical data relay device of the above is resumed, the path information acquired during the stop of the backup processing operation issubOutput to the logical data relay device.
[0061]
  According to this invention,subIn the logical data relay device, since the path information is not acquired while the backup processing operation is stopped, the third data processing means uses the path information acquired while the operation is stopped,MaineFrom the logical data relay devicesubBy sharing the path information, the path information is shared.
[0062]
  In the data relay system according to claim 26, at least two logically performing main processing and backup processing are performed.Main logical data relay device and subA data relay device constructed by a logical data relay device and data communication with the data relay deviceOther data relay deviceAnd a data relay system having a transmission path for establishing a connection between the data relay devices, the data relay deviceOf these, the main logical data relay device uses a connection type communication path switching protocol for performing the data relay, and a first connection means for establishing a connection with the predetermined other first data relay device And a first exchange means for exchanging the route information between the first data relay device connected by the first connection means and a first for storing the exchanged route information Storage means, first data processing means for processing data of path information stored in the first storage means, and the sub logical data relay device are connected communication for performing the data relay And a predetermined second data relay device different from the first data relay device to which the first connection means has established a connection. Second exchange means for exchanging the route information between the second connection means and the second data relay device established by the second connection means, and the exchanged route A second storage means for storing information; and a second data processing means for performing data processing of the path information stored in the second storage means; and the main and sub logical data relay devices; The first and secondExchanges route information for data relay between data relay devicesAt the same time, the first and second data processing means are exchanged with the first and second data relay devices, and the route information stored in the first and second storage means is synchronized. TakeIt is characterized byRu.
[0063]
  According to this invention,MaineLogical data relay devicesubDifferent from the logical data relay deviceFirst or secondBy connecting to the data relay device and exchanging route information, the number of connections on the backbone network is reduced and the route information traffic of the route information is reduced.
[0064]
  The data relay system according to claim 27 further comprises third storage means for storing an optimum route in the above invention.,The first and second data processing means select an optimal path based on the synchronized path information and store the optimal path in the third storage means. To do.
[0065]
  In the data relay system according to claim 28, in the above invention, the sub logical data relay device further comprises a first monitoring means for monitoring a main processing operation of the main logical data relay device, The second connection means establishes a new connection with the first data relay device to which the first connection means has established a connection according to the monitoring result of the first monitoring means, and the second exchange The means is characterized in exchanging the path information with the first data relay apparatus that has newly established a connection.
[0066]
  In the data relay system according to claim 29, in the above invention, the second connection means restarts the operation of the main processing by the main logical data relay apparatus from the monitoring result of the first monitoring means. If this is recognized, the newly established connection with the first data relay device is disconnected.
[0067]
  In the data relay system according to a thirty-third aspect, in the above invention, the second data processing means restarts the operation of the main process by the main logical data relay device from the monitoring result of the first monitoring means. If it is recognized, the route information acquired while the main processing operation is stopped is output to the main logical data relay device.
[0068]
  Further, in the data relay system according to claim 31, in the above invention, the main logical data relay device further comprises second monitoring means for monitoring a backup processing operation of the sub logical data relay device. The first connection means establishes a new connection with the second data relay device to which the second connection means has established a connection according to the monitoring result of the second monitoring means, and the first exchange The means is characterized in exchanging the path information with the second data relay apparatus that has newly established a connection.
[0069]
  In the data relay system according to a thirty-second aspect, in the above invention, the first connection means restarts the backup processing operation by the sub logical data relay apparatus from the monitoring result of the second monitoring means. If this is recognized, the newly established connection with the second data relay device is disconnected.
[0070]
  In the data relay system according to a thirty-third aspect, in the above invention, the first data processing unit restarts the backup processing operation by the sub logical data relay device from the monitoring result of the second monitoring unit. If it is recognized, the path information acquired while the backup processing operation is stopped is output to the sub logical data relay device.
[0071]
  In the data relay system according to claim 34,Logically perform at least two main processes and backup processesMain logical data relay device and subA data relay device constructed by a logical data relay device and data communication with the data relay deviceOther data relay deviceAnd aggregate the data to be relayedDeIn the data relay system having a data aggregation device and a transmission path for establishing a connection between the data relay device and the data aggregation device, the data relay deviceOf these, the main logical data relay device uses a connection-oriented communication path exchange protocol for performing the data relay, and a third connection means for establishing a connection with a predetermined first data aggregation device, Third exchange means for exchanging the route information with the first data aggregating apparatus established by the third connection means, and fourth storage means for storing the exchanged route information And third data processing means for performing data processing of the path information stored in the fourth storage means, wherein the sub logical data relay device is a connection type communication for performing the data relay. And a predetermined second data aggregating device different from the first data aggregating device to which the third connecting means has established a connection. Fourth and connecting means between said second data aggregation device strung connection by said fourth connection means, said path information that 4th data processing which performs the data processing of the path information memorize | stored in the 4th exchanging means which exchanges, the 5th memory | storage means which memorize | stores the said exchanged route information, and the said 5th memory means Means, the main and sub logical data relay devices, and the first and secondExchanges route information for data relay between data aggregation devicesAt the same time, the third and fourth data processing means are synchronized with the path information exchanged with the first and second data aggregating apparatuses and stored in the fourth and fifth storage means. TakeIt is characterized byThe
[0072]
  According to this invention,MaineLogical data relay devicesubDifferent from the logical data relay deviceFirst or second data aggregation deviceAnd the exchange of route information reduces the number of connections on the backbone network and reduces the route information traffic of the route information.
[0073]
  Further, in the data relay system according to claim 35, in the above invention, the data relay system further comprises sixth storage means for storing an optimum path, wherein the third and fourth data processing means are the synchronized paths. An optimum route is selected based on the information, and the optimum route is stored in the sixth storage means.
[0074]
  In the data relay system according to claim 36, in the above invention, the sub logical data relay device further comprises third monitoring means for monitoring a main processing operation of the main logical data relay device. 4 connection means establishes a new connection with the first data aggregating apparatus to which the third connection means has established a connection according to the monitoring result of the third monitoring means, and the fourth exchange The means is characterized in exchanging the path information with the first data aggregating apparatus that has newly established a connection.
[0075]
  In the data relay system according to claim 37, in the above invention, the fourth connection means restarts the operation of the main processing by the main logical data relay apparatus from the monitoring result of the third monitoring means. If this is recognized, the newly established connection with the first data aggregating apparatus is disconnected.
[0076]
  In the data relay system according to claim 38, in the above invention, the fourth data processing means restarts the operation of the main process by the main logical data relay apparatus from the monitoring result of the third monitoring means. If it is recognized, the route information acquired while the main processing operation is stopped is output to the main logical data relay device.
[0077]
  In the data relay system according to claim 39, in the above invention, the main logical data relay device further comprises fourth monitoring means for monitoring a backup processing operation of the sub logical data relay device. The third connection means establishes a new connection with the second data aggregating apparatus to which the fourth connection means has established a connection according to the monitoring result of the fourth monitoring means, and the third exchange The means is characterized in exchanging the path information with the second data aggregating apparatus that has newly established a connection.
[0078]
  In the data relay system according to claim 40, in the above invention, the third connection means restarts the backup processing operation by the sub logical data relay apparatus from the monitoring result of the fourth monitoring means. If this is recognized, the newly established connection with the second data aggregating apparatus is disconnected.
[0079]
  In the data relay system according to claim 41, in the above invention, the third data processing means restarts the backup processing operation by the sub logical data relay apparatus from the monitoring result of the fourth monitoring means. If it is recognized, the path information acquired while the backup processing operation is stopped is output to the sub logical data relay device. .
[0080]
DETAILED DESCRIPTION OF THE INVENTION
  Exemplary embodiments of a data relay method, a data relay device, and a data relay system according to the present invention will be described below with reference to the accompanying drawings of FIGS. In the following drawings, the same components are denoted by the same reference numerals for convenience of explanation.
[0081]
(Embodiment 1)
  FIG. 1 is a system configuration diagram showing a schematic configuration of a data relay system according to the present invention. In the figure, the data relay system of this embodiment isMain logical data relay device that performs main processing (this is called the active state)With main routers 41-61Sub logical data relay device that performs backup processing (this is called standby)The routers 40 to 60 are constructed from the backup routers 42 to 62, and the main routers 41 to 61 and the backup routers 42 to 62 are different.1st or 2nd data relay deviceConnected to the router's logical router. That is,When the data relay device according to the present invention is the router 40,The main router 41 of the router 40 isThe first data relay deviceA connection is established with the main router 51 of the router 50 via the transmission line 30, and the backup router 42Second data relay deviceA connection is established with the backup router 62 of the router 60 via the transmission line 31. Similarly,When the data relay device according to the present invention is the router 60,The main router 61 of the router 60 isThe first data relay deviceA connection is established with the backup router 52 of the router 50 via the transmission path 32. The routers 40 to 60 are also connected to different ISPs 11, thereby enabling data relay between the ISPs 11 and 11.
[0082]
  Since these main routers 41 to 61 have the same configuration, and the backup routers 42 to 62 have the same configuration, the configurations of the main router 41 and the backup router 42 are representatively shown in FIG. Show. In the figure, a main router 41 and a backup router 42 are connected via a dedicated transmission line 43. The main router 41 is connected to other routers (in this embodiment, the main router 51) via the transmission line 30.As the first connection meansInterface (hereinafter referred to as “I / F”) 41a and data processing using the BGP protocolAs the first data processing means and the first exchange meansA BGP processing unit 41b and a first connected to the BGP processing unit 41b and stores route informationAnd thirdA routing table 41c serving as storage means, a packet regular transmission control unit 41d for controlling the regular transmission of packets, and a communication unit 41e connected to the transmission path 43 and transmitting the packets.
[0083]
  The backup router 42 is connected to the transmission path 43, and monitors the reception state of the communication unit 42a that takes in the packet from the main router 41.As the first monitoring meansPerforms data processing using the packet reception monitoring unit 42b and the BGP protocol.As second data processing means and second exchange meansA BGP processing unit 42c, connected to the BGP processing unit 42c, stores route information exchanged with other routers and an optimum route.As second and third storage meansThe routing table 42d is connected to another router (in this embodiment, the backup router 62) via the transmission path 31.As a second connection meansIt is comprised from I / F42e.
[0084]
  In this main router 41, the BGP processing unit 41b exchanges route information with other routers via the I / F 41a as a BGP data processing function, and stores the received route information in the routing table 41c. Based on the route information, an optimum route is calculated and stored in the routing table 41c. Further, the BGP processing unit 41b synchronizes the route information with the BGP processing unit 42c in the backup router 42 to share the route information in the routing table.
[0085]
  The BGP processing unit 41b transmits and receives a KeepAlive message to / from another router via the I / F 41a, and changes its own operation state according to the reception status of the survival notification message. I am letting. Further, the BGP processing unit 41b sends an instruction to the packet periodic transmission control unit 41d so as to transmit this survival notification message also to the backup router 42 in the router 41.
[0086]
  The packet periodic transmission control unit 41 d periodically sends a survival notification message from the communication unit 41 e to the communication unit 42 a of the backup router 42 via the transmission path 43 based on an instruction from the BGP processing unit 41 b.
[0087]
  In the backup router 42,As the first monitoring meansThe packet reception monitoring unit 42b monitors the survival notification message captured by the communication unit 42a, and the packet reception monitoring unit 42b notifies the BGP processing unit 42c whether or not this survival notification message has been monitored within a predetermined time. is doing.
[0088]
  The BGP processing unit 42c exchanges route information with another router via the I / F 42e as a BGP data processing function, stores the received route information in the routing table 42d, and optimizes based on the route information. Simple routes are calculated and stored in the routing table 42d. Further, the BGP processing unit 42c synchronizes the route information with the BGP processing unit 41b in the main router 41 to share the route information in the routing table.
[0089]
  Further, the BGP processing unit 42c transmits / receives the survival notification message to / from another router via the I / F 42e, and changes its own operation state according to the reception status of the survival notification message. Furthermore, when the BGP processing unit 42c receives a notification from the packet reception monitoring unit 42b that the life notification message cannot be monitored, the BGP processing unit 42cAs the first data relay deviceRouter50(In this embodiment, a new connection is established with the main router 51 to exchange path information with each other.
[0090]
  The routing tables 41c and 42d store route information exchanged with other routers and route information synchronized with other logical routers within the own router.As a second storage meansRoute information table41c1, 42d1And the optimum route selected based on the route information is stored.As a third storage meansForwarding table41c2, 42d2And is composed respectively.
[0091]
  Next, the message format used by BGP including the life notification message transmitted / received between these routers 40 to 60 or between the logical routers 41 to 61 and 42 to 62 in these routers is shown in FIG. A description will be given based on each configuration diagram. The BGP message includes an IP and TCP header (not shown), a marker including a value that can be predicted by the receiver of the message shown in FIG. 3, a length indicating the length of the entire message including the header, and a message type code. It is comprised from the message header of BGP comprised from the type which shows, and the data part contained by the type of message.
[0092]
  This message type includes an open message that is sent after the transfer protocol connection is established, an update message that is used to transfer route information between BGP peers, and the existence check timer of the BGP processor does not time out. There are four types of survival notification messages exchanged between peers at sufficient intervals and NOTIFICATION messages sent when an error condition is detected.
[0093]
  Among these four message types, as shown in FIG. 4, the format of the open message includes a version indicating the protocol version of the message, a My Autonomous System (own autonomous system) indicating the autonomous system number of the message sender, and , A hold time indicating the number of seconds proposed as the survival confirmation timer value, a BGP identifier indicating the message sender's BGP identifier (IP address assigned to itself), and an optional parameter indicating the entire length of the optional parameter field It consists of a length and an optional parameter in which each parameter is coded in a column of optional parameters.
[0094]
  As shown in FIG. 5, the format of the update message is a non-forwardable route length indicating the entire length of the withdrawal route field, and a withdrawal route showing a variable length field including a list of IP address prefixes of routes where the service has stopped. , A total path attribute length indicating the entire length of the path attribute field, a path attribute indicating a path attribute consisting of a set of three terms, and network layer reachability information including a list of IP address fixes. Yes.
[0095]
  Note that the existence notification message is composed of only the message header shown in FIG. 3, and the notification message is not directly related to the present invention, so the description of this format is omitted.
[0096]
  Note that this standard protocol (BGP-4) message is also used in the internal communication between the main router and the backup router in the router. In this case as well, IP and TCP are used before the message format shown in FIG. A header is attached and a specific IP address reserved in advance for internal communication is used as the IP address. When confirming the processing operation, a code indicating the existence notification is added to the message header type shown in FIG. 3 and the existence notification message is transmitted. When synchronizing the route information, this message header type In addition, a code indicating an update is added, route information is added to the network layer reachability information shown in FIG. 5, and an update message including a path attribute is transmitted.
[0097]
  FIG. 6 is a state transition diagram showing an operation state in which the router transits by transmitting and receiving these messages. In the figure, the BGP transition state includes an idle state indicating the initial state of BGP, a connection state in which the connection of the transfer protocol is completed, and an attempt to obtain a peer by starting the transfer protocol connection. Active status, open transmission status indicating the status of waiting for open messages from peers, open confirmation status indicating status of waiting for survival notification messages and notification messages, and exchange of update messages, notification messages, and survival notification messages There is a connection establishment state which is a state to be performed.
[0098]
  Of these, the “active state” has a different meaning from the “active state” described in the “active state” main router described above. In other words, the “active state” of the state transitions represents only one of the operation states in which the logical router makes a transition, whereas the “active state” described above is an operation in which the main router performs the main processing. This is used to express the status of the backup router, as opposed to the “standby status” that represents the operating status of the backup router performing backup processing.
[0099]
  Both the main router and the backup router perform the state transition of the above-described operation. First, the BGP processing unit of these logical routers is a logical router which is another peer determined in advance from the idle state via the I / F. The connection to the transmission line is started and the connection to the transmission line is started, and the operation state is changed to the connection state. Here, if the connection is successful, an open message is transmitted to the connected logical router, and the state transitions to the open transmission state. When the connection fails, the operation state is changed to the active state.
[0100]
  In the open transmission state, when the BGP processing unit receives an open message from the other logical router, if there is no error in this message, the BGP processing unit transmits a survival notification message, and then transitions to the open confirmation state. Wait for survival notification message and notification message. Here, when the survival notification message is received, the state transitions to the established state, and when the notification message is received, the state transitions to the idle state. Further, the BGP processing units of the main router and the backup router transmit a survival notification message to the other logical router in the own device in the open transmission state.
[0101]
  In this connection established state, the BGP processing unit can exchange update messages, notification messages, and survival notification messages with the other logical router, and in this state, it can exchange route information with the other logical router. It becomes possible.
[0102]
  Next, the monitoring algorithm of the main router and backup router according to this embodiment, the main processing operationMadeThe monitoring algorithm will be described with reference to FIGS.
[0103]
  FIG. 7 is a flowchart for explaining a monitoring algorithm for the main router or backup router, which is a logical router, to monitor packet reception from other external logical routers. Since this monitoring algorithm is the same for both the main router and the backup router, in this embodiment, packet monitoring in the main router 41 of the router 40 will be described as an example.
[0104]
  In the figure, the BGP processing unit 41b of the main router 41 sends a survival notification message periodically transmitted from the main router 51 of the router 50 that is the connection partner when the transition state shown in FIG. Receiving via the I / F 41a (step 101). Then, the BGP processing unit 41b restarts the monitoring timer provided therein while the survival notification message is periodically received (step 102), and waits for the reception of the next survival notification message. Yes.
[0105]
  In this state, as shown in the schematic diagram illustrating the flow of the route information in FIG. 8, the main router 41 can exchange route information with the main router 51 using the update message. These are stored in the route information table (route information table 41c1 in the main router 41) in the routing table of each of the main routers 41 and 51. Further, the backup router 42 can exchange route information with the backup router 62 using the update message, and the exchanged route information is stored in the route information table (backup router 42 in the routing table of each backup router 42, 62). Then, it will be stored in the route information table 42d1).
[0106]
  In addition to the exchange of route information with the external router, the exchanged route information is synchronized between the main router 41 and the backup router 42. The synchronized route information is supplemented to each other and stored in the route information tables 41c1 and 42d1 in the routing tables 41c and 42d in the same manner as the route information from the outside so that the route information can be shared. It has been.
[0107]
  Further, the BGP processing units 41b and 42cAs first and second storage meansThe optimum route information is calculated based on the route information stored in the route information tables 41c1 and 42d1, and the calculated optimum route information is:As a third storage meansStored in the forwarding tables 41c2 and 42d2. The selection of the optimum route is determined by the transfer destination attribute of the BGP route.
[0108]
  Here, for example, as shown in FIG. 9, when the transmission line 30 connecting the main routers 41 and 51 is disconnected and the main router 41 cannot receive the survival notification message from the main router 51, this monitoring is performed. It is determined whether the timer has timed out (step 103). If the timeout has not occurred at this time, the BGP processing unit 41b returns to step 101 and waits for packet reception again. Also, if a timeout occurs at this point, the BGP processing unit 41b determines that a failure has occurred with the main router 51, and once transits from the idle state to the open transmission state. Then, a switching process for connecting to another new logical router is performed (step 104), the state transits to the connection establishment state through the open confirmation state, and the reception of the next survival notification message is waited at step 101.
[0109]
  As described above, in this embodiment, the main router and backup router in the same physical router establish a connection with different logical routers to exchange path information, thereby reducing the number of connections on the backbone network. Thus, the route information traffic of the route information can be reduced, thereby improving the transmission quality in normal data relay.
[0110]
  In this embodiment, when the route information is exchanged with an external router in each of the main and backup routers, the route information is synchronized between these routers, and the mutual route information is supplemented. It is possible to eliminate the adverse effects caused by the shortage of route information due to the decrease in the number and to share the route information.
[0111]
  Further, in this embodiment, when it becomes impossible to receive a packet from the connection partner, the connection partner router can be switched to another new router to receive the survival notification message and exchange route information. The adverse effects of reducing the number of connections can be compensated.
[0112]
  Next, the monitoring algorithm of the main router 41 in the own apparatus by the backup router 42 will be described using the flowchart of FIG. In the figure, the packet reception monitoring unit 42b of the backup router 42 monitors the survival notification message periodically transmitted under the control of the packet periodic transmission control unit 41d of the main router 41 when the operation state is the open transmission state. The unit 42c takes in the monitoring result from the packet reception monitoring unit 42b to determine whether or not the main processing operation by the main router 41 is normally performed (step 201).
[0113]
  Here, the BGP processing unit 42c determines that the operation of the main processing by the main router 41 is normally performed when the existence notification message is received from the main router 41 within a predetermined time, and automatically A BGP session is established with the backup router 62 of the router 61 determined as the connection partner of the router 42 (step 202). As a result, the BGP processing unit 42c becomes in a connection established state and can exchange route information with the backup router 62.
[0114]
  If no survival notification message is received from the main router 41 within a predetermined time, the BGP processing unit 42c determines that the operation of the main processing by the main router 41 is not normally performed, and this backup router Along with 62, a BGP session is established with the main router 51 of the router 50 that has been previously determined as the connection partner of the main router 41 (step 203). As a result, the BGP processing unit 42c becomes a connection established state, and exchange of route information with the backup router 62 and the main router 51 becomes possible.
[0115]
  In this state, as shown in the schematic diagram showing the flow of route information when the main router 41 side fails in FIG. 11, the backup router 42 can exchange route information with the backup router 62 using the update message. The exchanged route information is stored in the route information table 42d1 in the routing table of the backup router 42. The backup router 42 can exchange route information with the main router 51 using the update message, and the exchanged route information is also stored in the route information table 42d1.
[0116]
  Since the route from the main router is lost when the main router 41 side fails, the BGP processing unit 42c recalculates the optimum route information based on the route information stored in the route information table 42d1, The calculated optimum route information is stored in the forwarding table 42d2. In addition, when the backup router 42 is connected to the main router 51, a route from the main router 51 side can be created. Therefore, when the route information is learned after the connection is completed, the optimum route information is calculated again. The calculated optimum route information is stored in the forwarding table 42d2.
[0117]
  Further, the BGP processing unit 42c disconnects the connection with the main router 51 once and returns to the main router 41 via the main router 41 connected to the main router 51, as shown in the schematic diagram of FIG. Route information is exchanged. Since the main router 41 does not learn route information at the time of recovery, the BGP processing unit 42c can transmit the route information exchanged at the time of the failure to the main router 41. .
[0118]
  As described above, in this embodiment, the backup router in the same router monitors the main processing operation of the main router. If the main processing operation is not normal, the backup router connects to a predetermined logical router. Since it is possible to connect with the logical router of the other party of the main router and exchange route information, it is possible to eliminate the adverse effects caused by the shortage of route information due to the reduced number of connections. it can.
[0119]
(Embodiment 2)
  By the way, in the data relay apparatus according to the present invention, the main router can be configured to monitor the backup processing operation of the backup router. In this case, as shown in the configuration diagram of FIG. 13, the main router 41 monitors the reception state of the packet captured by the communication unit 41e.As a second monitoring meansA packet reception monitoring unit 41f is provided, and the backup router 42 is configured to include a packet regular transmission control unit 42f that controls regular packet transmission.
[0120]
  In this configuration, the packet transmission control unit 42f of the backup router 42 transmits a survival notification message to the main router 41, and the backup reception operation of the backup router 42 is performed by the packet reception monitoring unit 41f and the BGP processing unit 41b of the main router 41. Can also be monitored.
[0121]
  FIG. 14 is a flowchart for explaining a monitoring algorithm for the main router 41 to monitor the operation of the backup router 42 in its own apparatus. In the figure, the packet reception monitoring unit 41f of the main router 41 monitors the survival notification message periodically transmitted under the control of the packet periodic transmission control unit 42f of the backup router 42 when the operation state is the open transmission state. The unit 41b takes in the monitoring result from the packet reception monitoring unit 41f and determines whether the backup processing operation by the backup router 42 is normally performed (step 301).
[0122]
  Here, the BGP processing unit 41b determines that the backup processing operation by the backup router 42 is normally performed when the existence notification message is received from the backup router 42 within a predetermined time, and automatically A BGP session is established with the main router 51 of the router 50 determined as the connection partner of the router 41 (step 302). As a result, the BGP processing unit 41b is able to exchange route information with the main router 51 because the transition state becomes the connection established state.
[0123]
  If no survival notification message is received from the backup router 42 within a predetermined time, the BGP processing unit 41b determines that the backup processing by the backup router 42 is not normally performed, and the main router 51, a BGP session is also established with the backup router 62 of the router 60 that has been determined as the connection partner of the backup router 42 in advance (step 303). As a result, the BGP processing unit 41b is able to exchange route information with the main router 51 and the backup router 62 because the transition state becomes the connection established state.
[0124]
  Thus, in this embodiment, the main router in the same router monitors the backup processing operation of the backup router, and if the backup processing operation is not normal, the main router is connected to a predetermined logical router. Since it is also possible to connect with the logical router of the backup router's connection partner and exchange route information, the adverse effects caused by the shortage of route information due to a decrease in the number of connections can be resolved in this case as well. it can.
[0125]
  In the present invention, it is also possible to combine the first embodiment and the second embodiment. In this case, the main router and the backup router in the same router monitor each other's processing operations, By connecting to the logical router of the other side of the router and enabling the exchange of route information, it is possible to eliminate the adverse effects caused by the shortage of route information due to the decrease in the number of connections, and further redundancy is achieved. This increases the configuration and improves the reliability of data relay.
[0126]
(Embodiment 3)
  FIG. 15 is a system configuration diagram showing Embodiment 3 of the schematic configuration of the data relay system according to the present invention. In the figure, the data relay system of this embodiment isMain logical data relay device that performs main processingMain routers 41 and 51Sub logical data relay device that performs backup processingThe backup routers 42 and 52 are connected to different aggregation devices 23 and 24, respectively. That is, the main routers 41 and 51 of the routers 40 and 50 areAs the first data aggregation deviceA connection is established with the aggregation device 23 and is connected by transmission paths 30 and 31, respectively.As a second data aggregation deviceThe aggregation device 24 is connected to each other through transmission lines 32 and 33. The routers 40 and 50 are also connected to different ISPs 11 to enable data relaying between the ISPs 11. In addition to the routers 40 and 50, a plurality of routers are connected to the aggregation devices 23 and 24, and data received from each router is distributed to the corresponding routers.
[0127]
  Since the main routers 41 and 51 and the backup routers 42 and 52 have the same configuration and function as the main router and the backup router shown in FIG.DetailedDescription is omitted. In this embodiment, after the route information from each router is aggregated by the aggregation devices 23 and 24, this route information is distributed and transmitted to each main router and backup router. The operation of each main router and backup router performs the same operation as the router described in the first to third embodiments.
[0128]
  That is, in FIG. 2, the main router 41 includes an I / F 41a as third connection means (similar to the first connection means) connected to the aggregation device 23 via the transmission line 30, and data based on the BGP protocol. BGP processing unit 41b as third data processing means and third exchanging means (similar to the first data processing means and first exchanging means) for performing processing, and connected to this BGP processing unit 41b, and route information A routing table 41c as fourth and sixth storage means (first and third storage means) for storing the packet, a packet periodic transmission control unit 41d for controlling the periodic transmission of packets, and a transmission line 43, It is comprised from the communication part 41e which sends out this packet.
[0129]
  The backup router 42 is connected to the transmission path 43, and a communication unit 42a that takes in a packet from the main router 41, and a packet as third monitoring means (similar to the first monitoring means) that monitors the reception state of this packet. A reception monitoring unit 42b, a BGP processing unit 42c as a fourth data processing unit and a fourth exchanging unit (similar to the second data processing unit and the second exchanging unit) that perform data processing by the BGP protocol, Fifth and sixth storage means (second and third storage units) connected to the BGP processing unit 42c and configured to store route information exchanged with other aggregation devices (in this embodiment, the aggregation device 24) and optimum routes. The same as the storage means) and the fourth connection means (same as the second connection means) connected to the other aggregation devices via the transmission path 32. And a I / F42E and as). The routing information tables 41c1 and 42d1 of the routing tables 41c and 42d are fourth and fifth storage means (similar to the first and second storage means), and the forwarding tables 41c2 and 42d2 are sixth storage means ( It has the same function as the third storage means. Further, in FIG. 13, the packet reception monitoring unit 41f has a function of a fourth monitoring unit (similar to the second monitoring unit).
[0130]
  As described above, in this embodiment, the logical routers in the same router are connected to different aggregation devices, so that the same effect as in the first to third embodiments is obtained, and each router is aggregated by the aggregation device. Therefore, it is possible to acquire organized route information and to acquire route information with a large amount of information.
[0131]
(Embodiment 4)
  FIG. 16 is a system configuration diagram showing Embodiment 4 of the schematic configuration of the data relay system according to the present invention. In the figure, A to E are ISPs, and E represents route information held by other ISPs (A to D).,Learn and distribute using BGP. The E network includes routers 70 to 73, an aggregation device 25 that establishes a BGP session from the main routers of these routers 70 to 73, an aggregation device 26 that establishes a BGP session from a backup router of these routers 70 to 73, A LAN is constructed from a transmission path connecting these devices. In this network, the routing information is exchanged using the OSPF (Open Shortest Path First) routing protocol for the addresses of the LAN and routers 70 to 73.
[0132]
  Each of the routers 70 to 73 uses the BGP protocol, and the routers are directly connected to each other with a full mesh. BGP for intra-network communication (referred to as IBGP and communication with the outside as EBGP) The external route information learned in each session is exchanged.
[0133]
  Here, paying attention to the router 70, the router 70 confirms that the route addressed to D learned by the router 73 by EBGP is learned by IBGP and can be reached via the router 73. The route to the router 73 uses information learned by OSPF.
[0134]
  Thus, in this embodiment, a system can be constructed by combining an ISP using OSPF and an ISP using BGP according to the present invention, so that the above-described effects can be achieved and the system configuration can be simplified. It is possible to construct a highly versatile system.
[0135]
  The present invention is not limited to these embodiments, and various modifications can be made without departing from the spirit of the present invention. In the above-described embodiment, the example in which the BGP protocol is used as the route exchange protocol of the connection-type communication has been described. However, the present invention is not limited to this, and for example, an IDRP (Inter-Domain Routing Protocol) protocol is used. Is also possible.
[0136]
【The invention's effect】
  As described above, in the present invention, the routing control process is duplicated and logically set.Main and subSince each of the logical data relay devices connects with different data relay devices and exchanges route information between the connected data relay devices, the number of connections on the backbone network is reduced, It is possible to reduce the route information traffic of the route information, improve the reliability of data relay, and easily construct the system configuration.
[0137]
  Further, in the present invention, the routing control processing is duplicated and logically set.Main and subSince each of the logical data relay devices establishes a connection with a different data aggregation device and exchanges routing information between the connected data relay device and the data aggregation device, the number of connections on the backbone network is reduced. This reduces the route information traffic of the route information, increases the reliability of the data relay, and can easily construct the system configuration.
[0138]
  In the present invention,Main and subSince the exchanged route information is synchronized between the logical data relay devices of each other and the mutual route information is supplemented, the shortage of mutual route information due to the reduction in the number of connections is mutually supplemented. Can be shared.
[0139]
  In the present invention, since the optimum route is selected from the synchronized route information, an appropriate route such as the shortest route can be selected, and the reliability of data relay can be improved.
[0140]
  Moreover, according to this invention,subThe logical data relay device ofMaineMonitoring the main processing operation of the logical data relay deviceMaineIf it is determined that the logical data relay device is not performing this main processing,MaineSince the logical data relay apparatus establishes a new connection with another data relay apparatus that has established a connection and exchanges route information, the adverse effects of reducing the number of connections can be compensated.
[0141]
  Moreover, according to this invention,MaineWhen the operation of the main process by the logical data relay device is resumed,subSince the logical data relay device of the above disconnects the newly established connection with the other data relay device, it is possible to avoid establishing a double connection with the logical data relay device in the same data relay device. Thus, the number of connections can be reduced.
[0142]
  Moreover, according to this invention,MaineWhen the operation of the main process by the logical data relay device is resumed,subThe logical data relay device ofMaineSince the data is output to the data relay device, the path information can be shared.
[0143]
  Moreover, according to this invention,MaineThe logical data relay devicesubMonitoring the backup processing operation of the logical data relay device ofsubIf it is determined that the logical data relay device is not performing this backup process,subSince the logical data relay apparatus establishes a new connection with another data relay apparatus that has established a connection and exchanges route information, the adverse effects of reducing the number of connections can be compensated.
[0144]
  Moreover, according to this invention,subWhen the backup processing operation by the logical data relay device ofMaineSince the logical data relay device of the above disconnects the newly established connection with the other data relay device, it is possible to avoid establishing a double connection with the logical data relay device in the same data relay device. Thus, the number of connections can be reduced.
[0145]
  Moreover, according to this invention,subWhen the backup processing operation by the logical data relay device ofMaineThe logical data relay device ofsubSince the data is output to the logical data relay device, the path information can be shared.
[Brief description of the drawings]
FIG. 1 is a system configuration diagram showing a first embodiment of a schematic configuration of a data relay system according to the present invention;
2 is a configuration diagram showing configurations of a main router and a backup router shown in FIG. 1. FIG.
FIG. 3 is a block diagram showing a format of a BGP message header.
4 is a configuration diagram showing a format of an open message among the messages shown in FIG. 3. FIG.
FIG. 5 is a configuration diagram showing a format of an update message among the messages shown in FIG. 3;
FIG. 6 is a state transition diagram showing an operation state in which a router makes a transition.
FIG. 7 is a flowchart for explaining a monitoring algorithm for a logical router to monitor reception of a packet from another external logical router.
FIG. 8 is a schematic diagram showing a flow of route information in a router when route information is exchanged.
9 is a system configuration diagram showing a case where a disconnection occurs in a transmission line in the system shown in FIG.
FIG. 10 is a flowchart illustrating a monitoring algorithm for the backup router to monitor the operation of the main router in its own device.
FIG. 11 is a schematic diagram showing a flow of route information in the router when route information is exchanged when a failure occurs on the main router side.
FIG. 12 is a schematic diagram showing a flow of route information in the router when route information is exchanged when the main router is restored.
13 is a configuration diagram illustrating other configurations of the main router and the backup router illustrated in FIG. 1. FIG.
FIG. 14 is a flowchart for explaining a monitoring algorithm for the main router to monitor the operation of the backup router in its own device.
FIG. 15 is a system configuration diagram showing a third embodiment of the schematic configuration of the data relay system according to the present invention;
FIG. 16 is a system configuration diagram showing a fourth embodiment of the schematic configuration of the data relay system according to the present invention;
FIG. 17 is a system configuration diagram showing a schematic configuration of a first conventional example of a data relay system.
FIG. 18 is a system configuration diagram showing a schematic configuration of a second conventional example of a data relay system.
FIG. 19 is a system configuration diagram showing a schematic configuration of a third conventional example of a data relay system.
[Explanation of symbols]
  10 Backbone network
  11 ISP
  20, 40, 50, 60 routers
  21, 41, 51, 61 Main router (logical router)
  22, 42, 52, 62 Backup router (logical router)
  23-26, 70-73 Aggregation device
  30 to 33, 43 transmission line
  41a, 42e I / F
  41b, 42c BGP processor
  41c, 42d Routing table
  41c1, 42d1 route information table
  41c2, 42d2 forwarding table
  41d, 42f packet periodic transmission control unit
  41e, 42a Communication part
  41f, 42b Packet reception monitoring unit

Claims (41)

A plurality of data relaying apparatus, a data relaying method for relaying a logically build main process and at least two back up processing main logical data relay apparatus and the sub logical data relay apparatus each data,
The main logical data relay device establishes a connection with another first data relay device that is determined in advance as a connection partner of the own device , using a connection-oriented communication path exchange protocol for data relay. A first connecting step;
If the sub logical data relay device receives a survival notification message from the main logical data relay device within a predetermined time, it automatically uses a connection-oriented communication path switching protocol for data relay in advance. To establish a connection with another second data relay device determined as a connection partner of the device, and to perform data relay if no survival notification message is received from the main logical data relay device within a certain time Using the path exchange protocol of connection type communication, the first data relay device determined in advance as the connection partner of the second logical data relay device and the main logical data relay device determined in advance as the connection partner of the own device A second connection step for establishing a connection with the data relay device;
An exchange step of exchanging the path information between the logical data relay device that has established the connection and the first and second data relay devices;
A synchronization step of synchronizing the exchanged path information between the logical data relay devices set in the data relay device;
A data relay method comprising: A plurality of data relaying apparatus, a data relaying method for relaying a logically build main process and at least two back up processing main logical data relay apparatus and the sub logical data relay apparatus each data,
The main logical data relay device uses the connection type communication path exchange protocol for data relay, and the other data via the first data aggregating device determined in advance as the connection partner of the own device. A first connection step for establishing a connection with the relay device;
If the sub logical data relay device receives a survival notification message from the main logical data relay device within a predetermined time, it automatically uses a connection-oriented communication path switching protocol for data relay in advance. A connection is established with another data relay device via the second data aggregating device determined as the connection partner of the device, and if there is no reception of a survival notification message from the main logical data relay device within a certain time, Another data relay device and the main logical data are transmitted via the second data aggregating device, which is determined in advance as a connection partner of the own device, using a path switching protocol of connection-type communication for performing data relay. Second to establish a connection with another data relay device via the first data aggregation device determined as a connection partner of the relay device And the connection process,
An exchange step of exchanging the path information between the logical data relay device that has established the connection and the first and second data aggregation devices;
A synchronization step of synchronizing the exchanged path information between the logical data relay devices set in the data relay device;
A data relay method comprising: In the data processing method,
Each of the logical data relay devices is
A selection step of selecting an optimum route based on the route information synchronized in the synchronization step,
The data relay method according to claim 1 or 2, further comprising: In the data relay method,
The sub logical data relay device is:
A first monitoring step of monitoring whether the main logical data relay device is in a main processing operation;
If the main process is not in operation, a third connection step for newly establishing a connection with the other data relay device to which the main logical data relay device has established a connection;
A third exchanging step of exchanging the route information with the other newly established data relay device;
The data relay method according to claim 1, further comprising: In the data relay method,
Logical data relay device before Symbol Sub,
When the operation of the main process is restarted by the main logical data relay apparatus in the third connecting step, the first disconnection process to interrupt the connection strung new and the other data relay device,
5. The data relay method according to claim 4, further comprising: In the data relay method,
The sub logical data relay device is:
When the operation of the main process is restarted by the main logical data relay apparatus, to the main logical data relay device, a first output step of outputting the acquired path information in the main processing operation stop,
The data relay method according to claim 4, further comprising: In the data relay method,
The main logical data relay device is:
A second monitoring step of monitoring whether or not the sub logical data relay device is performing a backup processing operation;
If the backup processing is not in operation, a fourth connection step of newly establishing a connection with the other data relay device to which the sub logical data relay device has established a connection;
A fourth exchange step for exchanging the route information with the other newly established data relay device;
The data relay method according to claim 1, further comprising: In the data relay method,
The main logical data relay device is:
When the backup processing operation by the sub logical data relay device is resumed, in the third connection step, a second connection disconnecting step of disconnecting the newly established connection with the other data relay device,
The data relay method according to claim 7, further comprising: In the data relay method,
The main logical data relay device is:
When the operation of the backup processing by the sub logical data relay device is resumed, a second output step of outputting the path information acquired while the backup processing operation is stopped to the sub logical data relay device;
The data relay method according to claim 7 or 8, further comprising: Data relay device constructed by at least two main logical data relay devices and sub logical data relay devices that logically perform main processing and backup processing, and establishes connections with other data relay devices and relays data data In
The main logical data relay device is:
Using the routing exchange protocol connection-oriented communication for performing pre-Symbol data relay, a first connection means for tensioning the predetermined other first data relay apparatus and connection,
First exchange means for exchanging the path information with the first data relay device that has established a connection with the first connection means;
First storage means for storing the exchanged route information;
First data processing means for performing data processing of route information stored in the first storage means,
The sub logical data relay device is:
Using the routing exchange protocol connection-oriented communication for performing pre-Symbol data relay, the first of said first predetermined different second data relaying device and the connection between the data relaying device connection means stretched connection A second connecting means for stretching
A second exchanging means for exchanging the route information with the second data relay device that has established a connection by the second connecting means;
Second storage means for storing the exchanged route information;
Second data processing means for performing data processing of route information stored in the second storage means ,
The first and second data processing means are exchanged with the first and second data relay apparatuses, and synchronize route information stored in the first and second storage means. A data relay device. In the data relay device,
A third storage means for storing the optimum route;
The first and second data processing means select an optimal path based on the synchronized path information and store the optimal path in the third storage means. The data relay device according to claim 10. In the data relay device,
The sub logical data relay apparatus further includes a first monitoring means for monitoring the main processing operation of the main logical data relay device,
The second connection means establishes a new connection with the first data relay device with which the first connection means has established a connection according to the monitoring result of the first monitoring means,
The data relay apparatus according to claim 10 or 11, wherein the second exchange means exchanges the path information with the first data relay apparatus that has newly established a connection. Said second connecting means, the monitoring result of the first monitoring means, the operation of the main processing by the main logical data relay apparatus recognizes that it has been restarted, new said first data relaying device 13. The data relay device according to claim 12, wherein the established connection is disconnected. Said second data processing means, the monitoring result of the first monitoring means, the operation of the main processing by the main logical data relay apparatus recognizes that it has been resumed, acquired during the main processing operation stop 13. The data relay device according to claim 12, wherein route information is output to the main logical data relay device. In the data relay device,
The main logical data relay device is:
A second monitoring means for monitoring a backup processing operation of the sub logical data relay device;
The first connection means establishes a new connection with the second data relay device that the second connection means has established a connection according to the monitoring result of the second monitoring means,
The first exchange means exchanges the path information with the second data relay apparatus that has newly established a connection. Data relay device. When the first connection means recognizes from the monitoring result of the second monitoring means that the backup processing operation by the sub logical data relay apparatus has been resumed, the first connection means newly adds to the second data relay apparatus. 16. The data relay device according to claim 15, wherein the established connection is disconnected. When the first data processing unit recognizes from the monitoring result of the second monitoring unit that the backup processing operation by the sub logical data relay device has been resumed, the first data processing unit acquires the backup processing operation while it is stopped. 16. The data relay device according to claim 15, wherein the route information is output to the sub logical data relay device. In a data relay device that is constructed by at least two main logical data relay devices and a sub logical data relay device that logically perform main processing and backup processing, establishes a connection with the data aggregation device, and relays data of data,
The main logical data relay device is:
Using the routing exchange protocol connection-oriented communication for performing pre-Symbol data relay, and the third connecting means span the predetermined first data aggregation device and connection,
A third exchanging means for exchanging the route information with the first data aggregating apparatus connected by the third connecting means;
Fourth storage means for storing the exchanged route information;
Third data processing means for performing data processing of route information stored in the fourth storage means;
The sub logical data relay device comprises:
Using the routing exchange protocol connection-oriented communication for performing pre-Symbol data relay, the third connection means second data aggregation device and connection of different predetermined and said first data aggregation device strung connection A fourth connecting means for stretching
A fourth exchanging means for exchanging the route information with the second data aggregating apparatus connected by the fourth connecting means;
Fifth storage means for storing the exchanged route information;
Fourth data processing means for performing data processing of route information stored in the fifth storage means;
And the third and fourth data processing means are exchanged between the first and second data aggregating devices and stored in the fourth and fifth storage means. A data relay device characterized by synchronization . In the data relay device,
A sixth storage means for storing the optimum route;
The third and fourth data processing means select an optimal path based on the synchronized path information, and store the optimal path in the sixth storage means. The data relay device according to claim 18. In the data relay device,
The sub logical data relay device is:
Further comprising a third monitoring means for monitoring the main processing operation of the main logical data relay device,
The fourth connection means establishes a new connection with the first data aggregating apparatus with which the third connection means has established a connection according to the monitoring result of the third monitoring means,
20. The data relay apparatus according to claim 18, wherein the fourth exchange unit exchanges the path information with the first data aggregation apparatus that has newly established a connection. Said fourth connecting means, the monitoring result of said third monitoring means, when the operation of the main processing by the main logical data relay apparatus recognizes that it has been restarted, new said first data aggregation device The data relay apparatus according to claim 20, wherein the established connection is disconnected. The fourth data processing means, the monitoring result of said third monitoring means, operation of the main processing by the main logical data relay apparatus recognizes that it has been resumed, acquired during the main processing operation stop 21. The data relay apparatus according to claim 20, wherein route information is output to the main logical data relay apparatus. In the data relay device,
The main logical data relay device is:
A fourth monitoring means for monitoring a backup processing operation of the sub logical data relay device;
The third connection means establishes a new connection with the second data aggregating apparatus with which the fourth connection means has established a connection according to the monitoring result of the fourth monitoring means,
23. The path information exchange according to claim 18, wherein the third exchanging unit exchanges the path information with the second data aggregation device that has newly established a connection. Data relay device. When the third connection means recognizes from the monitoring result of the fourth monitoring means that the backup processing operation by the sub logical data relay apparatus has been resumed, the third connection means newly adds to the second data aggregation apparatus. 24. The data relay apparatus according to claim 23, wherein the established connection is disconnected. When the third data processing unit recognizes from the monitoring result of the fourth monitoring unit that the backup processing operation by the sub logical data relay device has been resumed, the third data processing unit acquires the backup processing operation while it is stopped. 24. The data relay apparatus according to claim 23, wherein route information is output to the sub logical data relay apparatus. Data relay device constructed by at least two main logical data relay devices and sub logical data relay devices that logically perform main processing and backup processing, and other data relay devices that communicate data with the data relay device And a data relay system having a transmission path for establishing a connection between these data relay devices,
Among the data relay devices , the main logical data relay device is:
A first connection means for establishing a connection with the predetermined other first data relay device using a path switching protocol for connection-type communication for performing the data relay;
First exchange means for exchanging the path information with the first data relay device that has established a connection with the first connection means;
First storage means for storing the exchanged route information;
First data processing means for performing data processing of route information stored in the first storage means;
The sub logical data relay device is:
A connection is established with a predetermined second data relay device that is different from the first data relay device to which the first connection means establishes a connection by using a path switching protocol of connection type communication for performing the data relay. A second connecting means for tensioning;
A second exchanging means for exchanging the route information with the second data relay device that has established a connection by the second connecting means;
Second storage means for storing the exchanged route information;
Second data processing means for performing data processing of route information stored in the second storage means;
Comprising a, as well as exchanging routing information for data relay between the main and sub logical data relaying device and said first and second data relaying apparatus, the first and second data processing means, wherein the first and second are exchanged between the data relay apparatus, and the first and second features and to Lud over data relay system to be synchronized routing information stored in the storage means. In the data relay device,
A third storage means for storing the optimum route ;
The first and second data processing means select an optimal path based on the synchronized path information and store the optimal path in the third storage means. The data relay system according to claim 26. In the data relay device,
The sub logical data relay device further includes first monitoring means for monitoring a main processing operation of the main logical data relay device,
The second connection means establishes a new connection with the first data relay device in which the first connection means has established a connection according to the monitoring result of the first monitoring means,
28. The data relay system according to claim 26 or 27, wherein the second exchanging means exchanges the path information with the first data relay apparatus that has newly established a connection. When the second connection means recognizes from the monitoring result of the first monitoring means that the operation of the main processing by the main logical data relay apparatus has been resumed, the second connection means newly adds to the first data relay apparatus. 29. The data relay system according to claim 28, wherein the established connection is disconnected. When the second data processing unit recognizes from the monitoring result of the first monitoring unit that the operation of the main processing by the main logical data relay device has been resumed, the second data processing unit acquires the main processing operation while it is stopped. 29. The data relay system according to claim 28, wherein route information is output to the main logical data relay device. In the data relay device,
The main logical data relay device is:
A second monitoring means for monitoring a backup processing operation of the sub logical data relay device;
The first connection means establishes a new connection with the second data relay device that the second connection means has established a connection according to the monitoring result of the second monitoring means,
The said 1st exchange means exchanges the said path | route information between the said 2nd data relay apparatus which newly established the connection, The one of Claims 26-30 characterized by the above-mentioned. Data relay system. When the first connection means recognizes from the monitoring result of the second monitoring means that the backup processing operation by the sub logical data relay apparatus has been resumed, the first connection means newly establishes the second data relay apparatus. 32. The data relay system according to claim 31, wherein the established connection is disconnected. When the first data processing unit recognizes from the monitoring result of the second monitoring unit that the backup processing operation by the sub logical data relay device has been resumed, the first data processing unit acquires the backup processing operation while it is stopped. 32. The data relay system according to claim 31, wherein route information is output to the sub logical data relay device. A data relay device constructed by at least two main logical data relay devices that logically perform main processing and backup processing and a sub logical data relay device, and another data relay device that communicates data with the data relay device In a data relay system having a data aggregation device that aggregates data to be relayed, and a transmission path that establishes a connection between the data relay device and the data aggregation device,
  Among the data relay devices, the main logical data relay device is:
A third connection means for establishing a connection with a predetermined first data aggregating apparatus using a connection-oriented communication path switching protocol for performing the data relay;
  A third exchanging means for exchanging the path information with the first data aggregating apparatus connected by the third connecting means;
Fourth storage means for storing the exchanged route information;
Third data processing means for performing data processing of route information stored in the fourth storage means;
The sub logical data relay device comprises:
A connection is established with a predetermined second data aggregating apparatus different from the first data aggregating apparatus that uses the connection-oriented communication path switching protocol for performing the data relay, and the third connection means establishes a connection. A fourth connecting means for tensioning;
A fourth exchanging means for exchanging the route information with the second data aggregating apparatus connected by the fourth connecting means;
Fifth storage means for storing the exchanged route information;
Fourth data processing means for performing data processing of route information stored in the fifth storage means;
Exchanging route information for data relay between the main and sub logical data relay devices and the first and second data aggregating devices, and the third and fourth data processing means, A data relay system characterized in that route information exchanged between the first and second data aggregating apparatuses and stored in the fourth and fifth storage means is synchronized. In the data relay device,
A sixth storage means for storing the optimum route;
The third and fourth data processing means select an optimal path based on the synchronized path information and store the optimal path in the sixth storage means. The data relay system according to claim 34. In the data relay device,
The sub logical data relay device is:
Further comprising third monitoring means for monitoring a main processing operation of the main logical data relay device;
The fourth connection means establishes a new connection with the first data aggregating apparatus with which the third connection means has established a connection according to the monitoring result of the third monitoring means,
36. The data relay system according to claim 34 or 35, wherein the fourth exchanging means exchanges the path information with the first data aggregating apparatus that has newly established a connection. When the fourth connection means recognizes from the monitoring result of the third monitoring means that the operation of the main processing by the main logical data relay apparatus has been resumed, the fourth connection means newly adds to the first data aggregation apparatus. The data relay system according to claim 36, wherein the established connection is disconnected. When the fourth data processing unit recognizes from the monitoring result of the third monitoring unit that the operation of the main processing by the main logical data relay device has been resumed, the fourth data processing unit acquires it while the main processing operation is stopped. 37. The data relay system according to claim 36, wherein route information is output to the main logical data relay device. In the data relay device,
The main logical data relay device is:
A fourth monitoring means for monitoring a backup processing operation of the sub logical data relay device;
The third connection means establishes a new connection with the second data aggregating apparatus with which the fourth connection means has established a connection according to the monitoring result of the fourth monitoring means,
The said 3rd exchanging means exchanges the said route information between the said 2nd data aggregation apparatus which newly established the connection, The any one of Claims 34-38 characterized by the above-mentioned. Data relay system. When the third connection means recognizes from the monitoring result of the fourth monitoring means that the backup processing operation by the sub logical data relay apparatus has been resumed, the third connection means newly adds to the second data aggregation apparatus. The data relay system according to claim 39, wherein the established connection is disconnected. When the third data processing unit recognizes from the monitoring result of the fourth monitoring unit that the backup processing operation by the sub logical data relay device has been resumed, the third data processing unit acquires the backup processing operation while it is stopped. 39. The data relay system according to claim 38, wherein route information is output to the sub logical data relay device.

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