JP5083432B2 - Route control apparatus and route control method - Google Patents

Description

  The present invention relates to a two-stage network in which a carrier-center center-side line is provided on one side and a carrier-base-side line is provided on the other side of a carrier. The present invention relates to a path control apparatus and a path control method in which a center side selects a base side line and determines a transmission route based on a line load state.

  Conventionally, a network design has been performed in which a center router and a base router are connected by a plurality of carrier networks to improve network reliability. FIG. 23 is a diagram illustrating a network configuration in which carriers are duplicated. In the configuration shown in FIG. 23, in order to optimize ROI (Routing Information Protocol), carrier services having different contents with respect to cost and bandwidth guarantee are combined.

  1. The service of carrier A is a service whose cost is high and the bandwidth cannot be increased, but the bandwidth is guaranteed. 2. On the other hand, it is assumed that the service of carrier B is a service (best effort) whose cost is low and a large bandwidth can be expected, but the bandwidth is not guaranteed. By combining these two carriers having different service contents, it is possible to design a network that guarantees the minimum bandwidth, can expect a large bandwidth, and is highly reliable at a reasonable cost.

  The center router 100 and the base router 101 in a network in a form in which such a plurality of carriers are combined (hereinafter referred to as a carrier redundant configuration) transmits communication data between the center side and the base side to the plurality of carriers A, Communicate using the B line properly. As a technology close to this configuration, there is multihoming in which connection to the Internet is connected by a plurality of ISP lines (see, for example, Patent Document 1 below).

  With the above configuration, both the center router 100 and the base router 101 distribute the load according to the load status of the connection lines of the carriers A and B to which the router itself is connected. For example, the load status of the connection line of the router itself is constantly monitored, and new communication is performed using the carrier A or B having a low load. This new communication is a packet unit, a communication host combination unit, a new session unit, or the like.

JP 2005-57487 A

  However, the data transmitted from the center side to the base side is distributed according to the load state of the line on the center side, not the load state of the line on the base side. Generally, the center-side line is designed with a band (line capacity) having a sufficient margin. As described above, if the distribution is performed according to the load condition of the line on the center side, the load condition of the line on the base side cannot be considered, and the optimum distribution in the center router 100 cannot be realized.

  As another distribution method, a configuration in which the ratio of distribution from the center router 100 to the base router 101 is fixedly defined is conceivable. In this method, distribution considering the difference in the contracted bandwidth of the connection lines of the carriers A and B of the base router 101 can be performed, but optimal distribution according to the status of the carrier connection lines of the actual base router 101 cannot be realized. . In particular, the above described 1.2. When the carriers A and B of the conflicting services are selected, a fixed value is not guaranteed in the bandwidth of the carrier B line, so that the distribution becomes insufficient just by fixedly allocating in advance.

  In order to eliminate the above-described problems caused by the conventional technology, the present invention can determine the route of the base side line at the time of transmission from the center side based on the load state of the base side, and the efficiency corresponding to the line capacity and service type An object of the present invention is to provide a route control device and a route control method that can use a typical line.

In order to solve the above-described problems and achieve the object, a path control device according to the present invention is provided with a center-side line between a carrier and a center on one side across a carrier, and the other side is a base-side line between a carrier and a base In the path control device provided on the center side on the two-stage network provided with a router, when receiving data from the base-side host to the center-side host, a router arranged on the base side Create a new entry in the load distribution table that associates the site side line selected according to the load status of the side line with the address of the host on the site side, and from the host on the center side to the host on the site side At the time of data transmission, the entry in the load distribution table is referred to, and the data is transmitted via the base line associated with the address of the host on the base side. Control means for selecting, when data transmission to the base side of the host from the center side of the host, the address of the center side of the host to see exempt the load distribution table, the host of the base side And a load balancing non-applicable registration table in which information on a combination of the address of the center and the TCP or UDP port number of the host on the center side is registered, and the control means from the host on the center side to the base When the data is transmitted to the host on the side, with reference to the load balancing non-applicable registration table, if the information of the combination is registered, the route control indicated by the entry of the load balancing table is not followed. Select the carrier that is set in association with the host on the base side and route it with the TCP or UDP port number. The specific communication protocol Tokoru type can not be determined, it detects a header of the upper protocol, and performs path control for that particular communication protocol.

  According to the above configuration, when data is transmitted from the center side to the base side, the data is transmitted via the base side line selected by the base side router when it was received from the base side immediately before, depending on the load status of the base side line. You can select the base line.

  According to the route control device and the route control method according to the present invention, the route of the base side line at the time of transmission from the center side to the base side can be determined based on the line state of the base side, corresponding to the line capacity and service type As a result, it is possible to perform efficient line use.

It is a figure which shows the structure of the route control apparatus of this invention. It is a figure which shows the structure by Embodiment 1 of the route control apparatus of this invention. It is a figure which shows the basic routing table provided in a center router. It is a figure which shows the routing table for load distribution provided in a center router. 4 is a flowchart showing the contents of selective activation processing of the center router in the first embodiment. 4 is a flowchart showing the transmission processing contents of the center router in the first embodiment. 4 is a flowchart showing the contents of reception processing of the center router in the first embodiment. It is a figure which shows the other structural example of the routing table for load distribution. It is a figure which shows the structure by Embodiment 2 of the route control apparatus of this invention. It is a figure which shows a load distribution application non-target registration table. 10 is a flowchart showing the transmission processing contents of the center router in the second embodiment. It is a figure which shows the other structural example of a load distribution application non-target registration table. It is a figure which shows the other structural example of a load distribution application non-target registration table. It is a figure which shows the other structural example of a load distribution application non-target registration table. It is a figure which shows the other structural example of a load distribution application non-target registration table. It is a figure which shows the other structural example of a load distribution application non-target registration table. It is a figure which shows the structure by Embodiment 3 of the route control apparatus of this invention. FIG. 10 is a diagram showing a basic routing table in the third embodiment. FIG. 10 is a diagram showing a load distribution routing table in the third embodiment. 10 is a flowchart showing a fault monitoring process of the center router in the third embodiment. 10 is a flowchart showing failure processing when a failure occurs in the third embodiment. FIG. 10 is a diagram illustrating a configuration example of a load distribution routing table in the fourth embodiment. FIG. 20 is a diagram illustrating a configuration example of a load balancing application excluded registration table in the fourth embodiment. FIG. 20 is a diagram illustrating a configuration example of a load distribution routing control IP protocol registration table in the fourth embodiment. 10 is a flowchart showing the contents of reception processing of a center router in the fourth embodiment. It is a figure which shows the network structure which duplicated the carrier.

  Exemplary embodiments of a path control device and a path control method according to the present invention will be explained below in detail with reference to the accompanying drawings.

The present invention distributes the link load of communication data between a center and a plurality of carrier lines in a carrier redundant configuration. In particular, link load distribution is performed at the center router in consideration of the load status of the line at the base router. The present invention relates to the following 1. ~ 3. Is assumed.
1. An intranet that connects a center and a base of an organization.
2. The connection between centers and bases shall be a carrier redundant configuration.
3. The communication protocol is, for example, TCP / IP.

  FIG. 1 is a diagram showing a schematic configuration of a route control device of the present invention. The link load distribution (load distribution) by the center router 100 as the route control device is performed depending on the load distribution control on the base router 101 side. The base router 101 can grasp the load state of lines such as carriers A and B to which the base router 101 is connected using existing technology.

The outline of the route control in the center router 100 will be described.
1. The base router 101 transmits data to the optimal (low load) carrier lines A and B according to the load of the carrier lines A and B in the carrier redundancy configuration.
2. The center router 100 learns the correspondence between the source IP address of the IP packet received from the base router 101 and the carrier lines A and B.
3. Data transmission from the center to the base is 2. Is transmitted to the carrier lines A and B corresponding to the corresponding IP address.

  With the above control, when transmitting data from the center side to the base side, the center router 100 transmits the data via the carrier line A or B selected by the base router 101 when it was received from the base side immediately before. Thereby, load distribution of a carrier redundant configuration can be performed.

  In the example shown in FIG. The base router 101 selects the carrier line B when transmitting data from the base host 102 (IP address: a). 2. The center router 100 learns the correspondence between the IP address: a and the carrier line B. A routing table is used for this learning. 3. The center router 100 receives data for the base host 102 (IP address: a) from the routing table. Is transmitted to the carrier line B with reference to the learning result. As described above, data transmission from the center side to the base side can be performed via the carrier line B having a large free band. As described above, efficient load distribution suitable for the service contents of the carrier lines A and B can be performed.

(Embodiment 1)
Embodiments 1 to 4 of the present invention will be described below. FIG. 2 is a diagram showing a configuration according to the first embodiment of the path control device of the present invention. FIG. 2 shows a model network configuration when the number of bases is 2 and the number of IP networks is 2 for simplicity of explanation.

  Two center hosts C1 and C2 are connected to the center via a center router 100. The center router 100 is connected to the lines L1 and L2, and the line L1 is connected to the carrier A via the gateway address G1. The line L2 is connected to the carrier B via the gateway address G2. In the following description, the lines L1 and L2 are appropriately referred to as transmission lines or center lines. On the base side, two base routers 101 (K1, K2) are arranged to manage different network addresses. These base routers K1 and K2 can be selectively connected to either carrier A or B. A plurality of base hosts (terminals such as PCs) K1-1 to K1-3 are arranged under the base router K1, and a plurality of base hosts (terminals such as PCs) K2 are under the base router K2. -1 to K2-3 are arranged.

  FIG. 3 is a diagram showing a basic routing table provided in the center router. The basic routing table 300 can be created by static registration by a command or dynamically by dynamic routing software, and can be created by using an existing technique. In the destination address / mask length, the network addresses under the base routers K1, K2 are registered. Two gateway addresses G1, G2 corresponding to this network address and transmission lines L1, L2 are registered.

  FIG. 4 is a diagram showing a load distribution routing table provided in the center router. The center router 100 dynamically creates a load distribution routing table 400 shown in FIG. This load distribution routing table 400 is a routing table for performing center load distribution in the base-dependent type, and the source addresses of the center hosts C1 and C2 and the base hosts K1-1 to K1-3 and K2 on the base side. Correspondences between the destination addresses -1 to K2-3, the gateway addresses G1 and G2, and the transmission lines L1 and L2 are created. The load distribution routing table 400 can realize a center-dependent center load distribution function.

  Next, the path control operation with the above configuration will be described with reference to FIGS. FIG. 5A is a flowchart showing the contents of the selection activation process of the center router in the first embodiment. The center router 100 waits for transmission or reception packets toward the center lines L1 and L2 (step S501), and at the time of transmission (step S502: transmission), activates transmission processing (step S503), and at the time of reception (step S502: Reception), the reception process is started (step S504). These path control operations are executed by a control unit (not shown) provided in the center router 100. Each of the above tables is configured by a storage unit (not shown) such as a memory. An entry is generated by the control unit or an operation input, and is referred to by the control unit when selecting a route.

  FIG. 5B is a flowchart of the transmission processing contents of the center router in the first embodiment. FIG. 5A shows the content of the transmission process activated by FIG. When the center router 100 receives the data (packet) addressed to the base host from the center host after the transmission processing is started, the center router 100 searches for an entry corresponding to the load distribution routing table 400 of FIG. 4 (step S510). . If there is an entry (step S511: exists), packet transmission is performed on the selected line (step S513), and one transmission is terminated. If there is no entry (step S511: none), the corresponding entry in the basic routing table 300 of FIG. 3 is searched to determine the transmission line (step S512), and then transmission is performed at step S513. End transmission.

  FIG. 5C is a flowchart of the reception processing contents of the center router in the first embodiment. The content of the reception process activated by FIG. When the center router 100 receives the data (packet) addressed to the center host from the base host after the reception processing is activated, the center router 100 searches for an entry corresponding to the load distribution routing table 400 of FIG. 4 (step S520). . If there is an entry (step S521: present), normal packet reception processing is performed on this packet (step S523), and one reception is terminated. If there is no entry (step S521: none), a new entry corresponding to the load distribution routing table 400 is added (step S522), reception is performed at step S523, and one reception is terminated. The number of entries created in the load distribution routing table 400 is the number of center hosts × the number of carriers × the number of base hosts. In the configuration shown in FIG. 2, 2 × 2 × 6 = 24 entries are created. The

A specific example of the above route control will be described with reference to FIG. 1. Follow the control process procedure. ~ 4. The symbol is attached. Further, in the initial state, there is no entry in the load distribution routing table 400 shown in FIG.
1. When the center router 100 receives data addressed to the base host K1-1 from the center host C1, the center router 100 refers to the routing table 400 for load distribution. Since there is no entry in the load distribution routing table 400 in the initial state, referring to the basic routing table 300 shown in FIG. 3, the transmission line L1, which matches the address (10.10.1.1.1) of the base host K1-1. Select L2. In this example, two lines L1 and L2 are candidates, but which one to select is selected from the existing technologies such as equal cost multipath operation or center line load. Can be used. In the example of FIG. 2, the line L1 of the carrier A is selected.

2. The base router 101 (K1) transfers the packet for the base host K1-1 received via the carrier A to the base host K1-1. At this time, when the base router K1 receives a response packet for the center host C1 from the base host K1-1, the base router K1 selects the base line of the carrier B having a low line load according to the line load state from the center of the terminal line toward the base. Assume that a packet is transmitted to the center host C1.

3. When the center router 100 receives a packet for the center host C1 from the base host K1-1 from the center line of the carrier B, the center router 100 adds a new entry shown in the routing table 400 for load distribution (source address (center host) C1): 10.10.0.1, destination address (base host K1-1): 10.10.1.1, gateway address: G2, outgoing line: L2).

4). Thereafter, when the center router 100 receives a subsequent packet for the base host K1-1 from the center host C1, referring to the load distribution routing table 400, the above 3. Since the corresponding entry created in step S1 exists, the subsequent packet is transmitted toward the center line L2 of the carrier B in accordance with the created setting contents. Thereafter, communication can be performed between the center host C1 and the base host K1-1 by switching to the carrier B having a low base line load.

  According to the above path control, the base router grasps the load status of the base line, selects a base line with a low load according to the load status, and transmits a packet to the center host. The center-side center router selects and transmits the center line connected to the base line selected by the base router so that the packet transmission to the base flows through the base line selected by the base router. In this way, the center router can grasp the load status of the base line without requiring a special protocol for exchanging information between the center router and the base router, and does not generate a line load on the network. Further, according to the above configuration, load distribution can be realized in units of combinations of center hosts and base hosts, so that flexible load distribution can be realized even in a network having a large number of hosts.

  FIG. 6 is a diagram illustrating another configuration example of the load distribution routing table. The load distribution routing table 600 shown in FIG. 6 may be configured by adding a TCP / UDP port number (for example, a socket number) to each item shown in FIG. In this case, the number of entries created in the load distribution routing table 600 is the number of center hosts × the number of carriers × the number of base hosts × the number N of ports. In the configuration shown in FIG. 6, 2 × 2 × 6 × N = 24 × N entries are created.

  In this way, it is possible to set whether or not to distribute lines for each application by performing route control in combination with port number units. For example, even in communication between a Web server on a center side and a browser on a host on a base side, it is possible to distribute lines by changing port numbers in units of Web pages. By distributing the lines, it is possible to reduce the line load because communication is performed using a plurality of lines as compared to communication using multiple data communication paths corresponding to the number of ports on one line. Also, by making the center host correspond to the center line that combines the port number (one center line for one center host or one center line for two center hosts), the center host function can be realized in units of port numbers. Flexible system construction is possible.

(Embodiment 2)
FIG. 7 is a diagram showing a configuration according to the second embodiment of the path control device of the present invention. Constituent parts similar to those in the first embodiment (FIG. 2) are denoted by the same reference numerals. The second embodiment has a configuration in which a maintenance terminal 700 such as a PC is connected to the center router 100 so that conditions not applicable to load distribution application described in the first embodiment can be set.

  FIG. 8 is a diagram illustrating a non-load distribution application target registration table. In addition to the basic routing table 300 (see FIG. 3), the load distribution routing table 400 (see FIG. 4), or the load distribution routing table 600 (see FIG. 6), the center router 100 applies load distribution. A non-target registration table 800 is further provided. In this load distribution application exclusion registration table 800, IP addresses of hosts that are not subject to the load distribution application described above are set. In the illustrated example, the IP address (10.10.0.1) of the center host C1 is set. This center host C1 is excluded from load balancing application.

  A control procedure of a path control operation performed by the center router in the above configuration will be described. Among the route control operations in the second embodiment, the contents of the selection activation process are the same as those in the first embodiment (see FIG. 5A), and the contents of the reception process are the same as those in the first embodiment (see FIG. 5-3). This is the same and will not be described.

  FIG. 9 is a flowchart showing the transmission processing contents of the center router in the second embodiment. The same processes as those in the first embodiment (see FIG. 5-2) are denoted by the same reference numerals. A different process is that a search (step S901) of the load distribution application exclusion registration table 800 is executed at the start of the transmission process. If a search is performed and there is an entry (step S902: present), step S512 is performed (a corresponding entry in the basic routing table 300 is retrieved to determine a transmission line). If there is no entry (step S902: none) Step S510 is executed (search for an entry corresponding to the load distribution routing table 400 or 600).

  As a result, the procedure 1. shown in FIG. ~ 4. Until then, the same processing as in FIG. 2 is executed. When the center host C1 transmits the base host K1-1, the center router 100 In accordance with the setting of the maintenance terminal 700, the load balancing application exclusion registration table 800 shown in FIG. 8 is searched. In the example shown in FIG. 8, since there is the center host C1 (IP address: 10.10.0.1) as an entry in the load balancing non-applicable registration table 800, the load balancing routing table 400 (see FIG. 4), or The transmission line is determined using the basic routing table 300 (see FIG. 3) without searching the load distribution routing table 600 (see FIG. 6). On the other hand, if there is no center host C1 (IP address: 10.10.0.1) as an entry in the load distribution non-applicable registration table 800, the load distribution routing table 400 (see FIG. 4) or the load distribution routing table. 600 (see FIG. 6) is searched and the corresponding transmission line is determined.

  As described above, by registering information that is not subject to load balancing in advance in the load balancing non-target registration table 800, for example, a specific center host guarantees a large amount of data with a bandwidth guarantee. Thus, when it is necessary to transmit for a long time, this center host is fixedly set in advance as a target to which the load balancing function shown in the first embodiment is not applied (in the configuration example of FIG. Communication using a certain carrier A) can be performed.

  In the configuration described above, the load distribution non-application target registration table 800 is set separately from the setting of the load distribution routing tables 400 and 600, and the target center host is determined. Not limited to this, a specific control entry that is not subject to load distribution may be fixedly registered with a command in the load distribution routing tables 400 and 600 described in FIG. 4 or FIG.

  Next, FIG. 10 is a diagram illustrating another configuration example of the load distribution application excluded registration table. In the load distribution non-applicable registration table 800 (see FIG. 8) described above, the setting that is not subject to load distribution is set on the center host side. However, the load distribution non-applicable registration table 1000 shown in FIG. In addition, it is possible to configure the base host side. In the example shown in FIG. 10, the base host K1-1 (IP address: 10.10.1.1) is set not to be subject to load distribution. Thereby, when a specific base host is scheduled to receive a large amount of data intensively for a long time, the base host can be excluded from the application of the load distribution function shown in the first embodiment. It is possible to guarantee communication bandwidth for each host and to expect a large bandwidth.

  Next, FIG. 11 is a diagram illustrating another configuration example of the load distribution application exclusion target registration table. The configuration of the load distribution non-applicable registration table 1100 shown in FIG. 11 sets a combination of the IP address of the center host, the IP address of the base host, and the communication use TCP / UDP port number that are not applicable to load distribution. It is a thing. This combination includes: 1. Combination of the IP address of the center host and the IP address of the base host 2. Combination of center host IP address and communication TCP / UDP port number 3. Combination of IP address of base host and communication use TCP / UDP port number A combination of the IP address of the center host, the IP address of the base host, and the communication use TCP / UDP port number is conceivable.

  According to the above configuration, for example, it is possible to select whether the center line is fixedly determined by the combination of the IP address and the port number or the load is distributed in units of applications. Specifically, it is possible to perform non-target registration for load distribution application for each type of application that requires quality assurance and for each application type that requires performance expectation, thereby realizing flexible path control.

  Next, FIG. 12 is a diagram illustrating another configuration example of the load distribution application excluded registration table. According to the configuration of the load distribution non-applicable registration table 1100 shown in FIG. 11 described above, it is necessary to register one entry at a time that is not applicable to load distribution. At the maximum, an entry of the number of center hosts × number of carriers × number of base hosts × number of ports N must be entered as a command, and the number of operation inputs for entry becomes enormous. In the setting shown in FIG. 12, for the transmission source TCP / UDP port number, the TCP (or UDP) transmission source port number of the packet from the center host to the base host is set. The IP address is a collective setting (any command) for all IP addresses.

  In the example of the load distribution non-applicable registration table 1200 shown in FIG. 12, for the center side application that uses 500 (UDP) for the source TCP / UDP port number, the load distribution is performed regardless of the center host and the base host. Communication using a fixed communication line based on the basic routing table 300 (see FIG. 3) can be performed.

  According to the above configuration, by setting to any that covers all the IP addresses of the non-applicable center host and the base host, all IP addresses for the non-applicable center host and the base host are targeted, It is possible to save the trouble of registering the IP addresses of the center host and the base host one by one. In addition, it is possible to easily perform non-target registration for load balancing for each type of center-side application that requires quality assurance and for each type of center-side application that requires performance expectations, and realizes flexible route control. it can.

  Next, FIG. 13 is a diagram illustrating another example of the configuration of the load distribution non-applicable registration table. In the setting of the load balancing non-applicable registration table 1300 shown in FIG. 13, for the transmission destination TCP / UDP port number, the TCP (or UDP) transmission destination port number of the packet from the center host to the base host is set. For the IP addresses related to the non-applicable center host and the base host, all IP addresses are set as targets (any command).

In the example of FIG. 13, the base routing table 300 (FIG. 13) is excluded from the load distribution target regardless of the center host and the base host for applications on the base side that use 500 (UDP) as the destination TCP / UDP port number. 3), communication using a fixed communication line can be performed.

  According to the above configuration, by setting to any that targets all of the IP addresses of the non-applicable center host and the base host, all IP addresses of the non-applicable center host and the base host are targeted, Therefore, it is possible to save the trouble of registering each IP address of each center host and each base host one by one. Depending on the setting of the source port number or destination port number, registration for excluding load balancing application is performed for each type of application on the site side that requires quality assurance and each type of application on the site side that requires performance expectations. It can be performed easily and flexible path control can be realized.

  Next, FIG. 14 is a diagram illustrating another configuration example of the load distribution application exclusion target registration table. In the example of the load distribution non-applicable registration table 1400 shown in FIG. 14, the setting of the load distribution non-applicable registration table (FIGS. 8, 10, 11, 12, and 13) described in the second embodiment is set. It is an example put together in one table.

  Explaining each entry, the non-applicable center host IP address is the center host C1 (IP address: 10.10.0.1), and the non-applicable base host IP address is the base host K1-1 (IP address: 10.10). Regarding 1.1), the source TCP / UDP port number 500 (UDP) and the destination TCP / UDP port number 500 (UDP) are not subject to load balancing. Further, the non-applicable center host IP address is the center host C1 (IP address: 10.10.0.1), and the non-applicable base host IP address is the base host K2-1 (IP address: 10.10) shown in FIG. Regarding 2.1), when the source TCP / UDP port number is 30 (UDP), load distribution is not applicable. Further, the non-applicable center host IP address is the center host C2 (IP address: 10.10.0.2) shown in FIG. 7, and the setting of the any command as the non-applicable base host IP address is the destination TCP / When the UDP port number is 1000 (TCP), load distribution is not applicable. Also, regarding the setting where the non-applicable center host IP address is “any” and the non-applicable base host IP address is “any”, the load distribution is not applicable when the destination TCP / UDP port number is 125 (TCP). .

  According to the above configuration, a wide range of requests such as quality assurance, performance improvement, line determination in IP address units, line determination in application type units, etc. can be made in one table. It is possible to set the path control corresponding to the required communication quality with a simple setting.

(Embodiment 3)
FIG. 15 is a diagram showing a configuration according to Embodiment 3 of the path control device of the present invention. The third embodiment is configured to perform path control corresponding to the occurrence of a communication line failure, and includes a failure monitoring unit (not shown). The same components as those in the second embodiment (FIG. 7) are denoted by the same reference numerals. Further, the same route control (see FIG. 9) as that of the second embodiment is performed. FIG. 16 is a diagram showing the basic routing table 300 in the third embodiment (the same setting contents as in FIG. 3), and FIG. 17 is a diagram showing the load distribution routing table 600 in the third embodiment (FIG. 6). And the same setting content). In addition, although not shown, a load balancing application exclusion registration table (for example, FIG. 14) is also set.

  Control at the time of path failure detection will be described with reference to FIGS. 18-1 and 18-2. FIG. 18A is a flowchart of the fault monitoring process of the center router in the third embodiment. The center router 100 performs failure monitoring of the center line, the IP network (carriers A and B), and the base line (step S1801). A failure occurs not only in a line but also in a device arranged on the line, but the occurrence of a failure in this device can be similarly monitored (detected). If no failure has occurred in any of these (step S1802: no failure has occurred), one monitoring is terminated. Thereafter, the process of step S1801 is re-executed. On the other hand, if it is detected that a failure has occurred in any of the center line, the IP network, and the base line (step S1802: failure occurrence), failure processing is started (step S1803), and one monitoring is terminated.

  FIG. 18-2 is a flowchart illustrating failure processing when a failure occurs in the third embodiment. The contents of the failure process activation in FIG. In the failure processing, the failure occurrence route is deleted from the basic routing table 300 (step S1810), the failure occurrence route is deleted from the load distribution routing table 600 (step S1811), and the processing is terminated.

Specifically, using FIG. 15, it is assumed that route control is performed using the basic routing table 300 and the load distribution application routing table 600.
1. When the center router 100 receives a packet for the base host from the center host, the center router 100 refers to the load distribution non-target registration table 1400 shown in FIG. Then, it is determined whether the packet is received from the center host to which the load distribution function is applied, and when the packet is received from the center host C1 to be applied, the load distribution routing table 600 is referred to. Since the corresponding entry (IP address whose source address is the center host C1: 10.10.0.1) exists in the load distribution routing table 600, the center line L2 (gateway address G2) of the carrier B is set according to the setting. ) To send to.

  In this state, the center router 100 generates a failure X on the center line as shown in FIG. 15 on the route used for transmission (in addition, the failure of the IP network (carrier B) or the base line can be detected). If detected, the target route 1601 in which the failure is detected is deleted from the basic routing table 300 shown in FIG. At the same time, the target route 1701 in which the failure is detected is also deleted from the load distribution routing table 600 shown in FIG. Thereafter, when the center router 100 receives a subsequent packet, the center router 100 transmits the packet toward a normal center line (center line L1).

2. The base router 101 (K1) transfers the packet received via the carrier A to the base host K1-1.
3. Next, when the base router 101 (K1) receives a response packet for the center host C1 from the base host K1-1, the base router 101 (K1) selects the base line of the carrier A where no failure has occurred and is directed to the center host C1. Send the packet. Thereafter, communication is performed between the center host C1 and the site host K1 using the carrier A that has no trouble on the line.

4). When the center router 100 receives a packet for the center host C1 from the base router 101 (K1) from the center line of the carrier A, the center router 100 adds a new entry 1702 corresponding to the route distribution to the routing table 600 for load distribution. . As shown in FIG. 17, this new entry 1702 includes a source address 10.10.0.1, a destination address 10.10.1.1, a gateway address G1, a TCP / UDP port number 500 (UDP), This is the transmission line L1.

5). Thereafter, when a subsequent packet for the base host K1-1 is received from the center host C1, the load balancing application target is first referred to by referring to the load balancing non-target registration table (for example, FIG. 14) as described above. If the packet is received from the center host to which load distribution is applied, the load distribution routing table 600 is referred to and the carrier A center line is determined according to the contents of the corresponding entry. Transmit to L1. If the load distribution is not applicable, the basic routing table 300 is referred to and a transmission line that matches the address of the base host K1-1 is selected.

  According to the third embodiment described above, as described in the first embodiment, the center router can grasp the load situation of the base line and perform the route control, and the trouble of the line or equipment occurs. Since the entry of the corresponding route is deleted from the routing table at that time, it is possible to select a route that avoids the failure occurrence route. In addition, since the route that communicated after the failure occurred is newly registered as an entry in the routing table, communication through the normal line and equipment that is the new route can be performed. Can be operated without stopping.

(Embodiment 4)
In the fourth embodiment of the present invention, for a specific communication protocol in which the protocol type cannot be determined by the TCP or UDP port number, a higher-level protocol header is detected and a different route is selected for each communication protocol type.

  FIG. 19 is a diagram illustrating a load distribution routing table of the center router according to the fourth embodiment. The first entry of the load distribution routing table 1900 is the same communication protocol (TCP / UDP) as in the first embodiment (see FIG. 6). The second entry is an RTP communication protocol (IP protocol) different from the first entry. The RTP communication protocol is a protocol such as voice communication over the IP protocol. The RTP communication protocol is a protocol such as UDP or TCP in which the protocol type cannot be determined by the port number. However, the load distribution as described above can be performed by checking the upper protocol (RTP protocol) header.

  When the center router 100 receives a packet for the center host C2 from the base host K1-2 from the center line of the carrier B, the center router 100 adds a second entry to the load distribution routing table 1900. The second entry in FIG. 19 includes a source address (center host C2): 10.10.0.2, a destination address (base router K1-2, see FIG. 15 etc.): 10.10.1.2, Gateway address: G2, TCP / UDP port number: RTP, outgoing line: L2. RTP is used for streaming audio, video data, and the like.

  FIG. 20 is a diagram showing a load balancing application exclusion registration table according to the fourth embodiment. The entries from the top to the fourth entry in the non-load balancing application registration table 2000 shown in FIG. 20 are the same as the registration contents described in the second embodiment (see FIG. 14). The fifth entry is a non-applicable center host IP address (center host C2): 10.10.0.2, a non-applicable base host IP address (base host K1-2): 10.10.1.2, a transmission source TCP / UDP port number: RTP, destination TCP / UDP port number: RTP.

  Next, FIG. 21 is a diagram showing a load distribution routing control IP protocol registration table according to the fourth embodiment. In the fourth embodiment, this load distribution routing control IP protocol registration table 2100 is newly used. This load distribution routing control IP protocol registration table 2100 is provided to perform load distribution of lines for IP protocols in addition to TCP / UDP port numbers. The entries in the example of FIG. 21 are: center host IP address (center host C2): 10.10.0.2, base host IP address (base host K1-2): 10.10.1.2, source IP protocol Number: RTP, destination IP protocol number: RTP. In the load distribution routing table 1900, any can be set for the center host IP address and the base host IP address (see FIG. 12 for an example of setting any). With any setting, the operation registration for entry can be saved.

  When the center router 100 receives a packet from the base router 101 (K1, K2) toward the center hosts C1, C2 from the center lines of the carriers A, B, the center router 100 corresponds to a new load distribution routing table 1900 shown in FIG. Add an entry. When this new entry is made, if an IP protocol entry is registered in the load distribution routing control IP protocol registration table 2100 shown in FIG. 21, the new entry corresponding to the IP protocol is stored in the load distribution routing table 1900. It comes to register. Detailed processing will be described below.

  FIG. 22 is a flowchart showing the reception processing contents of the center router in the fourth embodiment. The contents of transmission processing performed by the center router 100 are the same as those in the second embodiment (see FIG. 9), and the description thereof is omitted.

  In the reception process performed by the center router 100 in FIG. 22, when data (packet) addressed to the center host is received from the base host, a search is made as to whether there is a corresponding entry in the load distribution routing table 1900 (step S2201). If there is an entry (step S2202: present), a new entry (TCP / UDP compatible) is added to the load distribution routing table 1900 (step S2203), and normal packet reception processing is performed on this packet (step S2202). (S2207) One reception is terminated.

  On the other hand, if there is no entry in the load distribution routing table (step S2202: none), the load distribution routing control IP protocol registration table 2100 is searched first (step S2204). If there is no entry for the IP protocol in the load balancing routing control IP protocol registration table 2100 (step S2205: None), the process proceeds to step S2203 because it is other than the IP protocol. On the other hand, if there is an IP protocol entry in the load distribution routing control IP protocol registration table 2100 (step S2205: present), a new entry (IP protocol compatible) is added to the load distribution routing table 1900 (step S2206), and this packet A normal packet reception process is performed for (step S2207), and one reception is completed. The load distribution routing table 1900 to which an entry has been added during the above reception processing becomes a search target during transmission processing from the center router 100 to the base routers K1 and K2 (see, for example, FIG. 9).

  According to the fourth embodiment described above, a specific communication protocol is registered using the load distribution routing control IP protocol registration table, and an entry for each communication protocol is added to the load distribution routing table during reception processing. Therefore, for a specific communication protocol in which the protocol type cannot be determined by the TCP or UDP port number, the header of the upper protocol can be detected and different path control can be performed for each communication protocol type. For example, it is possible to perform path control for load distribution of normal text, file data, etc. to a TCP / UDP communication protocol, and to perform path control for load distribution to an IP protocol such as voice or video data. You will also be able to. As a result, it is possible to prevent transmission delay of transmission packets for each communication protocol. Furthermore, since it is possible to prevent the RTP protocol analysis and processing time from being delayed, load distribution corresponding to various communication protocols can be easily performed.

  According to the first to fourth embodiments described above, the center router can use the line used for transmission by the base router for packet transmission. It is possible to select a line advantageous to the side. At this time, since it is possible to specify up to the port number on the center side or the base side, for example, it is possible to distribute the line load in units of Web pages.

  Furthermore, when line load balancing is not applied, for example, a line with guaranteed bandwidth can be used in a fixed manner. Therefore, depending on whether or not the IP addresses of the center host and base host are set, It is possible to select whether to perform line load balancing or to guarantee bandwidth. Similarly, it is possible to select whether to perform line load distribution or to guarantee bandwidth for each application depending on whether or not the port numbers of the center host and the base host are set.

  For example, as described with reference to FIG. 23, by performing load distribution in a redundant configuration in which carriers A and B of different services are combined, the characteristics of each service can be used to the maximum while effectively utilizing the line. It becomes like this.

  The route control procedures described using the flowcharts in the first to fourth embodiments described above can be realized by executing a program prepared in advance on a computer such as a personal computer or a workstation. This program is recorded on a computer-readable recording medium such as a hard disk, a flexible disk, a CD-ROM, an MO, and a DVD, and is executed by being read from the recording medium by the computer. The program may be a transmission medium that can be distributed via a network such as the Internet.

(Supplementary note 1) A route provided on the center side on a two-stage network in which a carrier side-center center line is provided on one side and a carrier-base side line is provided on the other side of the carrier In the control device,
When receiving data from the host on the site side to the host on the center side, the router on the site side selects the site side line selected according to the load status of the site side line, and the address of the host on the site side Create a new entry in the load balancing table
Control means for referring to an entry in the load balancing table and routing the base side line associated with the address of the base side host during data transmission from the center side host to the base side host A path control device comprising:

(Supplementary Note 2) The control means includes:
The new entry to be created in the load balancing table is connected to the transmission source IP address of the base side host, the destination IP address of the center side host, the gateway address for the carrier, and the gateway address. The route control device according to attachment 1, wherein the transmission line is associated with the transmission line.

(Supplementary Note 3) The control means includes:
The routing control apparatus according to appendix 2, wherein a TCP or UDP port number of the host on the center side is further associated as a new entry created in the load distribution table.

(Supplementary note 4) When data is transmitted from the center-side host to the base-side host, the load-balancing application target in which the address of the center-side host that does not apply the reference of the load distribution table is registered is not applicable It has a registration table,
The control means includes
When transmitting data from the center-side host to the base-side host, if the address of the center-side host is registered with reference to the load-balancing-inapplicable registration table, an entry in the load-balancing table The route control device according to any one of appendices 1 to 3, wherein the route that is set in advance in association with the center-side host is selected without following the route control indicated by.

(Supplementary Note 5) When transmitting data from the center-side host to the base-side host, the load-balancing application target in which the address of the base-side host that does not apply the reference of the load balancing table is registered is not applicable It has a registration table,
The control means includes
When transmitting data from the center-side host to the base-side host, the load-balancing-inapplicable registration table is referred to, and if the address of the base-side host is registered, the load-balancing table entry The route control device according to any one of appendices 1 to 3, wherein the route that is set in advance in association with the host on the base side is selected without following the route control indicated by.

(Appendix 6) The address of the center-side host and the address of the base-side host that are not applicable to the load distribution table reference when data is transmitted from the center-side host to the base-side host And a load balancing non-applicable registration table in which information on a combination of the TCP or UDP port number of the center-side host is registered,
The control means includes
When data is transmitted from the center-side host to the base-side host, the load distribution non-applicable registration table is referred to, and if the combination information is registered, the path indicated by the load distribution table entry The route control device according to any one of appendices 1 to 3, wherein the route that is set in advance in association with the host on the base side is selected without following the control.

(Supplementary note 7) When transmitting data from the center-side host to the base-side host, data transmission from the center-side host to the base-side host that does not apply to the load distribution table reference A load balancing non-applicable registration table in which the source port number of TCP or UDP at the time is registered,
The control means includes
When sending data from the center side host to the base side host, referring to the load balancing non-applicable registration table, if the TCP or UDP source port number at the time of data transmission is registered, the load The route according to any one of appendices 1 to 3, wherein the carrier that is set in advance in association with the host on the base side is selected without following the route control indicated by the entry of the distribution table. Routing device.

(Supplementary note 8) In the load balancing non-applicable registration table, all of the addresses of the center-side hosts or all of the addresses of the base-side hosts that are not applicable to the load balancing table reference are The route control device according to appendix 7, wherein a command for batch setting is used.

(Supplementary note 9) The control means includes:
Any one of appendices 6 to 8, wherein a header of a higher-order protocol is detected for a specific communication protocol whose protocol type cannot be determined by the TCP or UDP port number, and path control for the specific communication protocol is performed. The routing control device according to one.

(Supplementary Note 10) Provided with failure monitoring means for monitoring the occurrence of a failure in a route from the center host to the base host,
The control means includes
10. The path control device according to any one of appendices 1 to 9, wherein an entry in the load distribution table corresponding to the path in which the failure has occurred is deleted.

(Supplementary note 11) In the route control method of the route control device provided on the center side on the network of the carrier redundant configuration in which the center side and the base side are connected by a plurality of different carrier networks and communicate with each other,
When receiving data from the base-side host to the center-side host, a new entry that associates the carrier selected by the router arranged at the base-side with the address of the base-side host is stored in the load distribution table. A new entry creation process to be created;
A route selection step of referencing an entry in the load distribution table and routing the carrier associated with the address of the base-side host at the time of data transmission from the center-side host to the base-side host; ,
A path control method comprising:

  As described above, in the route control device and the route control method according to the present invention, the carrier-center-side center-side line is provided on one side and the other side is provided with the base-side line between the carrier-site. This is useful for a two-stage network.

100 Center router 101 (K1, K2) Base router 102 (K1-1 to K1-3, K2-1 to K2-3) Base host 300 Basic routing table 400 Load distribution routing table A, B Carrier C1, C2 Center host G1, G2 gateway address L1, L2 line (center line)

Claims (3)

In the path control device provided on the center side on a two-stage network in which a carrier side-center center line is provided on one side and a carrier-base side line is provided on the other side,
When receiving data from the host on the site side to the host on the center side, the router on the site side selects the site side line selected according to the load status of the site side line, and the address of the host on the site side Create a new entry in the load balancing table
Control means for referring to an entry in the load balancing table and routing the base side line associated with the address of the base side host during data transmission from the center side host to the base side host When,
At the time of data transmission from the center-side host to the base-side host, the center-side host address, the base-side host address, and the center that are not applicable to the load distribution table reference are applied. A load balancing non-applicable registration table in which information on a combination with the TCP or UDP port number of the host on the side is registered,
The control means includes
When data is transmitted from the center-side host to the base-side host, the load distribution non-applicable registration table is referred to, and if the combination information is registered, the path indicated by the load distribution table entry Without following the control, route the carrier set in advance in association with the base-side host,
For a specific communication protocol whose protocol type cannot be determined by the TCP or UDP port number, the header of the upper protocol is detected, and the path control for the specific communication protocol is performed.
A path control device characterized by that. The control means includes
The new entry to be created in the load balancing table is connected to the transmission source IP address of the base side host, the destination IP address of the center side host, the gateway address for the carrier, and the gateway address. 2. The route control device according to claim 1, wherein the route control device is associated with a transmission line. The path of the path control device provided on the center side on a two-stage network in which a carrier-center center-side line is provided on one side and a carrier-base-side line is provided on the other side of the carrier In the control method,
When receiving data from the base-side host to the center-side host, the base-side line selected by the router arranged on the base-side according to the load status of the base-side line is set to the address of the base-side host. A new entry creating step for creating a new entry associated with the load balancing table in the load balancing table;
A step of referring to an entry in the load distribution table when routing data from the center-side host to the site-side host and routing the site-side line associated with the address of the site-side host ; ,
At the time of data transmission from the center-side host to the base-side host, the center-side host address, the base-side host address, and the center that are not applicable to the load distribution table reference are applied. Referring to the load balancing non-applicable registration table in which the information on the combination with the TCP or UDP port number of the host on the side is registered, and if the information on the combination is registered, the entry of the load balancing table indicates A step of route-selecting the carrier set in advance in association with the base-side host without following route control;
For a specific communication protocol whose protocol type cannot be determined by the TCP or UDP port number, detecting a header of the upper protocol and performing path control for the specific communication protocol;
A path control method comprising:

Images