JP2004032569A - Route control system by ospf - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To allow each router to be devoted to an original route control processing by removing a load on calculating the shortest route from each router. <P>SOLUTION: A route calculating device 200 is arranged separately from the routers 101, 102, and 103, as the device devoted to the processing to calculate the shortest routes based on data indicating a link state (a link state database 1). The routers 101, 102, and 103 are dedicated to the original route control processing from which the load on calculating the shortest routes is removed by the existence of the route calculating device 200. Thus, the routers obtain the calculation result of the route calculating device 200, and, then, hold the aggregation of the shortest routes with each router as a start point in each route table 2. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention is one of link state and path control protocols for performing a path control based on a link state which is a connection state between a router (route control device) and a network (a group of lines and a group of terminals connecting the router and the router). The present invention relates to a path control system (a path control system based on OSPF) realized by an OSPF (Open Shortest Path First).
[0002]
[Prior art]
OSPF, one of the link state routing protocols, is a routing protocol devised for performing routing in a relatively large-scale network system.
[0003]
That is, OSPF is a path control protocol related to link state path control disclosed as Request For Comments (RFC) 2328 by the Internet Engineering Task Force (IETF).
[0004]
The feature of this OSPF is that while the conventional distance vector type routing protocol exchanges the entire routing table of its own between routers, only the link state is exchanged between routers, and the calculation of the shortest route is The point is that each router does.
[0005]
As a result, the OSPF has an advantage that the amount of data exchanged between routers is very small and the size can be reduced regardless of the size of the network system, as compared with the conventional distance vector algorithm. ing.
[0006]
The OSPF as described above divides an AS (Autonomous System), which is a set of routers on which the OSPF operates, into a plurality of areas called areas, and all routers belonging to an area use the same link state database. To allow each router to calculate the shortest path from itself to all destinations based on its link state database.
[0007]
[Problems to be solved by the invention]
The above-described conventional technique (route control system using OSPF) has a problem that a large amount of CPU (Central Processing Unit) resources of a router are consumed.
[0008]
The reason that such a problem exists is that the distance vector type algorithm only receives and registers the path information, whereas according to the link state path control protocol, every time the link state is changed, This is because the shortest route is recalculated on the router.
[0009]
Due to this problem, at the time of recalculation of the shortest path, a situation may occur in which a task of the path control protocol occupies CPU resources and other tasks operating on the router cannot operate.
[0010]
In view of the above, an object of the present invention is to provide a dedicated processing step for calculating a shortest path from a link state in a network system having a router (route control apparatus) operating OSPF which is a link state path control protocol. The load on the calculation of the shortest path is removed from the router by causing the device (route calculation device) to perform the calculation (providing a dedicated device for the shortest path calculation and preventing the router itself from calculating the shortest path). , So that routers can concentrate on the original route control processing, and allow all routers to distribute (have) the information of the shortest route without having each router calculate the shortest route, An object of the present invention is to provide an OSPF-based route control system that can solve the above problems.
[0011]
[Means for Solving the Problems]
The route control system based on OSPF of the present invention is a network system in which route control is performed by OSPF, a group of data indicating link states of all routers and all networks belonging to an area in which the own router (router in which the self is present) exists. A link state database in each router having a, and a route table in each router holding information indicating `` the shortest path set of the own router is the starting point '' calculated based on the link state database, A link state database constructing unit in each router that constructs the link state database in the OSPF having a “function of constructing a link state database”; and the own router when the own router is a computing device connection router. Link in each router that sends a copy of the link state database to the route calculation device A state database transmitting unit, and when the own router is a computing device connection router, receiving from the route computing device routing table information indicating the shortest route set for all routers calculated by the route computing device, The route table information receiving unit in each router that registers the shortest route set (the shortest route set starting from the own router) with respect to the own router in the information in the route table in the own router, and the route table information received by the own router An inter-router routing table information transmission unit in each router that transmits the remaining routing table information obtained by deleting the shortest path set related to the own router to an adjacent router (connected to the own router and the network), and transmitted from the adjacent router The received route table information is received, and the shortest route set for the own router in the received route table information (the shortest route set where the own router is the start point) is received. An inter-router routing table information receiving unit in each router to be registered in the routing table in the router; a link status database receiving unit receiving a copy of the link state database sent from a computing device connection router; A shortest path calculation unit that calculates the shortest path based on the copy of the link state database received by the database reception unit and generates a shortest path set for all routers, and a shortest path calculated and generated by the shortest path calculation unit A routing table information transmitting unit that transmits (returns) routing table information indicating a routing set to the computing device connection router, and includes the routing device provided in one area.
[0012]
Further, the OSPF-based route control system of the present invention has, in a network system in which OSPF-based route control is performed, a data group representing the link status of all routers and all networks belonging to the area where the own router is located. A link state database in each router, a route table in each router holding information indicating “the shortest path set whose own router is the starting point” calculated based on the link state database, and a “link state” in the OSPF. A link state database constructing unit in each router that constructs the link state database, and a path calculation device that connects a copy of the link state database of the own router to the own router. Link state database transmitter in each router to send to Receiving the routing table information indicating the shortest path set for all the routers calculated by the continuous path calculation apparatus from the path calculation apparatus connected to the own router, and determining the shortest path for the own router in the received routing table information. A route table information receiving unit in each router that registers a route set (the shortest route set whose own router is the starting point) in the route table in the own router, and a link that receives a copy of the link state database sent from the router A state database receiving unit, a shortest path calculating unit that calculates a shortest path based on a copy of the link state database received by the link state database receiving unit to generate a shortest path set for all routers, and the shortest path A routing table information transmitting unit for transmitting (returning) the routing table information indicating the shortest route set calculated and generated by the calculating unit to the router; Have, it is also possible to configure so as to have a total router each said path computation device provided one by one with respect to the.
[0013]
The OSPF-based route control system of the present invention is more generally used as a dedicated device that executes a process of calculating the shortest route based on data indicating a link state in a network system in which OSPF-based route control is performed. A route calculation device provided separately from the router, and a configuration in which the load on the calculation of the shortest route is removed by the presence of the route calculation device so that the path calculation device can concentrate on the original route control processing. Can be expressed as having each router that can hold the set of the shortest paths that are the starting points by acquiring (receiving) the router.
[0014]
Further, in the network system in which the route control is performed by the OSPF, the route calculation device, which is a dedicated device provided separately from the router, executes a process of calculating the shortest route based on the data indicating the link state. A path calculation device program for causing the router to function so that the load on the calculation of the shortest route is removed by the presence of the route calculation device so that the router can concentrate on the original route control processing. It is also possible to realize as a path control system by OSPF having a router program for functioning so as to be able to hold the set of the shortest paths that are the starting points by acquiring the calculation result of the calculation device. .
[0015]
BEST MODE FOR CARRYING OUT THE INVENTION
Next, the present invention will be described in detail with reference to the drawings.
[0016]
(1) First embodiment
[0017]
FIG. 1 is a block diagram showing a configuration of a path control system based on OSPF according to the first embodiment of the present invention.
[0018]
FIG. 2 is a diagram showing a configuration of a network system to which the OSPF routing control system according to the present embodiment is applied.
[0019]
Referring to FIGS. 1 and 2, the OSPF-based route control system according to the present embodiment includes a router group (routers 101, 102, and 103) and a network group (networks 104, 105, and 106). And a route calculation device 200.
[0020]
As shown in FIG. 2, it is assumed that the router 101, the router 102, and the router 103 belong to one of the “areas” (referred to as “area 100”) which is a concept on the OSPF.
[0021]
It goes without saying that the number of routers and the manner of connection between the routers and the network are not limited to those illustrated. Furthermore, the route calculation device 200 is connected to the router 101, but this is not fixed, and the relation between the routers is equal (the router 101 is not a special router).
[0022]
The routers (routers 101/102/103) exchange information indicating a link state with each other, and perform route control using a route table 2 described later.
[0023]
Each network (networks 104/105/106) is composed of a group of lines and a group of terminals, and connects routers.
[0024]
One route calculation device 200 is arranged for one area (the area 100 in the present embodiment), and is a router 101 (calculation) which is an arbitrary one of the routers included in the area 100. Connected to the device connection router, and generates routing table information indicating the shortest path set by using a copy (copy data) of the link state database 1 received from the computing device connection router, and calculates the routing table information by the calculation. Return (send) to the device connection router.
[0025]
Each of the routers 101/102/103 holds a link state database 1 and a path table 2, and includes a link state database construction unit 3, a link state database transmission unit 4, a path table information reception unit 5, and a router It is configured to include a routing table information transmitting unit 6 and an inter-router routing table information receiving unit 7. Here, the function realized by the link state database construction unit 3 is a function that also exists in the conventional technology (technology related to OSPF), but includes a link state database transmission unit 4, a routing table information reception unit 5, a routing table between routers. The function realized by the information transmitting unit 6 and the inter-router route table information receiving unit 7 is a new function in the present invention.
[0026]
The link state database 1 has a data group representing the link states of all routers and all networks belonging to the area 100. The contents of the link state database 1 are the same for all routers.
[0027]
The route table 2 holds information indicating the shortest route set starting from the own router (router in which the own router) is calculated based on the link state database 1.
[0028]
The link state database constructing unit 3 has a "function of constructing a link state database" which also exists in the related art, and constructs the link state database 1 according to the same procedure as in the related art.
[0029]
The link state database transmission unit 4 has a function of transmitting a copy of the link state database 1 owned by the own router to the path calculation apparatus 200 when the own router is a router connected to a computing device.
[0030]
When the own router is a router connected to a computing device, the routing table information receiving unit 5 receives the shortest route set (route table information) for all routers calculated by the routing device 200 from the routing device 200 and receives it. It has a function of registering the shortest route set (the shortest route set starting from the own router) related to the own router in the routing table information in the routing table 2 in the own router.
[0031]
The inter-router routing table information transmitting unit 6 transmits the remaining routing table information obtained by deleting the shortest route set related to the own router from the routing table information received by the own router to an adjacent router (connected to the own router and the network). With the ability to
[0032]
The inter-router route table information receiving unit 7 receives the route table information transmitted from the adjacent router, and determines the shortest route set (the shortest route set starting from the own router) regarding the own router in the received route table information. It has a function of registering in the routing table 2 in the router.
[0033]
The route calculation device 200 includes a link state database receiving unit 8, a shortest route calculating unit 9, and a route table information transmitting unit 10.
[0034]
The link state database receiving unit 8 has a function of receiving a copy of the link state database 1 sent from the computing device connection router.
[0035]
The shortest path calculation unit 9 has a “function of calculating the shortest path” existing on the router even in the conventional technology (technology related to OSPF), and is a copy of the link state database 1 received by the link state database reception unit 8. The shortest path is calculated based on the shortest path and a shortest path set for all routers is generated.
[0036]
The routing table information transmitting unit 10 has a function of transmitting (returning) the routing table information indicating the shortest route set calculated and generated by the shortest route calculating unit 9 to the computing device connection router.
[0037]
FIG. 3 is a flowchart showing processing of the routing control system by the OSPF according to the present embodiment. This processing includes a link state database construction step A1, a link state database copy transmission step A2, a shortest path calculation step A3, a path table information transmission step A4, an own router start point shortest path set extraction step A5, and a path table registration. It comprises a step A6, a shortest path set deletion step A7, a shortest path set empty determination step A8, and a routing table information adjacent router transmission step A9.
[0038]
FIG. 4 is a block diagram for explaining a specific operation of the OSPF-based route control system according to the present embodiment.
[0039]
Next, the overall operation of the OSPF-based route control system configured as described above according to the present embodiment will be described in detail with reference to FIGS.
[0040]
The link state database construction unit 3 in the router 101, the router 102, and the router 103 creates the link state database 1 as shown by an arrow A in FIG. Construction) (step A1 in FIG. 3).
[0041]
Here, the contents of the link state database 1 are completely the same in all the routers (the router 101, the router 102, and the router 103) belonging to the area 100.
[0042]
Next, as shown by an arrow B in FIG. 4, the link state database transmission unit 4 in the computing device connection router (router 101) copies the copy (copy data) of the link state database 1 created in step A1. The data is transmitted to the route calculation device 200 (step A2).
[0043]
The link state database receiving unit 8 in the route calculation device 200 receives the copy of the link state database 1 transmitted in step A2.
[0044]
The shortest path calculation unit 9 uses the copy of the link state database 1 received by the link state database reception unit 8 to generate a “shortest path from the router 101 to all destinations ( The shortest path set from the router 101 as the starting point), the shortest path from the router 102 to all the destinations (the shortest path set from the router 102 as the starting point), and the shortest path from the router 103 to all the destinations (the router 103 (The shortest path set at the start point) "(step A3).
[0045]
The routing table information transmitting unit 10 uses the set of all the shortest routes (the shortest route set) calculated in step A3 as routing table information as shown by an arrow C in FIG. 101) (send) (step A4).
[0046]
The routing table information receiving unit 5 in the computing device connection router receives the routing table information transmitted in step A4 and, based on the received routing table information (shortest path set), sets the shortest path set for the own router (when the own router is the starting point). A set of all the shortest paths) is extracted (step A5), and as shown by an arrow D in FIG. 4, the extracted information (the shortest path set starting from the own router) is stored in the routing table 2 in the own router. Register (step A6).
[0047]
Further, the inter-router route table information transmitting unit 6 in the router (here, the router 101) transmits the shortest route set extracted in step A5 (the shortest route set starting from the own router) to the route table information receiving unit 5. Alternatively, it is deleted from the routing table information received by the router-to-router routing table information receiving unit 7 (here, the routing table information receiving unit 5) (step A7), and the shortest route in the routing table information after the deleting process of step A7 is performed. It is checked (determined) whether the set is empty (step A8).
[0048]
If the inter-router route table information transmitting unit 6 determines that “the shortest route set is empty” in the check in step A8, the process illustrated in FIG. 3 ends.
[0049]
On the other hand, when the inter-router route table information transmitting unit 6 determines that “the shortest route set is not empty” in the check in step A8, as illustrated by an arrow E in FIG. Then, the routing table information after the deletion processing in step A7 is transmitted to the routers (here, router 102 and router 103) adjacent to the router 101) (step A9).
[0050]
The router 102 and the router 103 that have received the routing table information perform the same operation as the above-described operation in the router 101 (the operation in Steps A5 to A9), and thereby the shortest path set for the own router (the own router is the starting point). The shortest route set) is registered in the route table 2 in the own router.
[0051]
That is, for example, in the router 102, the inter-router route table receiving unit 7 receives the route table information transmitted from the router 101, and determines the own router (router 102) from the shortest route set in the route table information. The shortest path set (the set of all the shortest paths starting from the own router) is extracted (step A5), and the extracted information (the shortest path set) is stored in the own router as shown by an arrow F in FIG. (Step A6).
[0052]
Further, the inter-router routing table information transmitting unit 6 in the router 2 deletes the shortest route set extracted in step A5 from the routing table information received by the inter-router routing table information receiving unit 7 (step A7), It is checked whether or not the shortest path set in the routing table information after the deletion processing in step A7 is empty (step A8), and when it is determined that it is "empty", the processing in FIG. If it is determined that the route table information is not empty, the router 103, which is a router adjacent to the own router (router 102) (excluding the router 101 that is the source of the route table information to the own router), sends the route table information (step A7). Is transmitted (step A9).
[0053]
In the first embodiment, even though the shortest path set for the own router is already registered in the routing table 2, the inter-router route table information receiving unit 7 determines the shortest path set for the own router. There may be a case where routing table information including the information is received. In such a case as well, the same information is merely registered in a superimposed manner and no inconvenient result is produced. However, in order to deal with the problem more appropriately, the following features (additional operations) ) Can be considered.
[0054]
a. The inter-router routing table information receiving unit 7 in each router “registers the shortest route set for the own router extracted from the received routing table information in the routing table 2” (see steps A5 and A6 in FIG. 3). Is performed, it is checked whether the information to be registered has already been registered. That is, in the series of processes in FIG. 3, after the process of step A5, the information extracted in step A5 (the shortest route set starting from the own router) is already registered in the routing table 2 in the own router. A “registered determination step A5 ′” is provided for determining whether or not this is the case.
[0055]
b. If it is determined in step A5 'that "it has been registered", control is transferred to the inter-router routing table information transmitting unit 6 in order to eliminate the waste of re-registering (overwriting) the same information. (Control is transferred to the process of step A7 without performing the process (registration process) of step A6 in FIG. 3).
[0056]
c. If it is determined in step A5 'that "it has not been registered", "the process of registering the shortest route set to the route table 2" in step A6 in FIG. 3 is performed as described above.
[0057]
(2) Second embodiment
[0058]
FIG. 5 is a block diagram showing a configuration (including an arrow for explaining the operation) of a path control system using OSPF according to the second embodiment of the present invention.
[0059]
FIG. 6 is a diagram showing a configuration of a network system to which the OSPF routing control system according to the present embodiment is applied.
[0060]
Referring to FIG. 5 and FIG. 6, the OSPF-based route control system according to the present embodiment includes a group of routers (routers 101, 102, and 103) and a group of networks (networks 104, 105, and 106). And a group of route calculation devices (route calculation device 201, route calculation device 202, and route calculation device 203).
[0061]
As shown in FIG. 6, it is assumed that the router 101, the router 102, and the router 103 belong to one of the "areas" (referred to as "area 100") which is a concept on the OSPF.
[0062]
Referring to FIGS. 1 and 2 and FIGS. 5 and 6, in the first embodiment, one route calculation device (route calculation device 200) is prepared for one area (area 100). On the other hand, the present embodiment (the second embodiment) is different in that one route calculation device is prepared for each of the routers belonging to the area 100. That is, as shown in FIGS. 5 and 6, the route calculation device 201, the route calculation device 202, and the route calculation device 203 are connected to the router 101, the router 102, and the router 103, respectively.
[0063]
It goes without saying that the number of routers and the manner of connection between the routers and the network are not limited to those illustrated.
[0064]
The routers (routers 101/102/103) exchange information indicating a link state with each other, and perform route control using a route table 2 described later.
[0065]
Each network (networks 104/105/106) is composed of a group of lines and a group of terminals, and connects routers.
[0066]
Each route calculation device (route calculation device 201/202/203) uses the copy (copy data) of the link state database 1 received from the router 101/102/103 to which it is connected, and indicates the shortest route set. It generates table information and returns (transmits) the routing table information to the routers 101/102/103.
[0067]
Each of the routers 101/102/103 holds a link state database 1 and a path table 2, and includes a link state database construction unit 3, a link state database transmission unit 4, and a path table information reception unit 5. It is configured. These components are the same as those having the same names in the routers 101/102/103 in the first embodiment (see FIG. 1).
[0068]
Each of the route calculation devices 201/202/203 includes a link state database receiving unit 8, a shortest route calculating unit 9, and a route table information transmitting unit 10, respectively. These components are the same as the components (see FIG. 1) of the same name in the route calculation device 200 according to the first embodiment.
[0069]
FIG. 7 is a flowchart showing processing of the routing control system by the OSPF according to the present embodiment. This process includes a process B10 on the router 101 and the route calculation device 201 side, a process B20 on the router 102 and the route calculation device 202, and a process B30 on the router 103 and the route calculation device 203 (the process B10 on the router 101 and the route calculation device 201 side, the router B10). The process B20 on the 102 & route calculation device 202 side and the process B30 on the router 103 & route calculation device 203 side exist in parallel.)
[0070]
Each of the process B10 on the router 101 & route calculation device 201 side, the process B20 on the router 102 & route calculation device 202 side, and the process B30 on the router 103 & route calculation device 203 side include link state database construction steps B11 / B21 / B31 and link state database copy. Transmission step B12 / B22 / B32, shortest path calculation step B13 / B23 / B33, path table information transmission step B14 / B24 / B34, own router start point shortest path set extraction step B15 / B25 / B35, and path table registration It consists of steps B16 / B26 / B36.
[0071]
Next, an overall operation of the OSPF-based route control system according to the present embodiment configured as described above will be described with reference to FIGS.
[0072]
In the first embodiment described above, the router 101, which is the computing device connection router, determines the routing table information (the shortest route set) by the processing of steps A7 to A9 in FIG. And the router 3.
[0073]
On the other hand, in the present embodiment (second embodiment), all of the routers (the router 101, the router 102, and the router 103) are directly connected to the route calculation device to which the router is connected. (Each of the route calculation device 201, the route calculation device 202, and the route calculation device 203) receives the route table information indicating the shortest route set. Therefore, the operation related to transmitting the routing table information from the router (for example, the router 101) to the adjacent routers (for example, the router 102 and the router 103) becomes unnecessary.
[0074]
On the other hand, in the present embodiment, all routers and route calculation devices (combinations of the routers 101/102/103 and the route calculation devices 201/202/203 connected thereto) have the same steps as in the first embodiment. The processing of A1 to step A4 (see FIG. 3) is required.
[0075]
That is, in the present embodiment, the router 101 and the route calculation device 201 perform the first implementation as shown by arrows in steps B11 to B16 in FIG. 7 and the router 101 and the route calculation device 201 in FIG. The same operations (operations) as the operations (processes) of steps A1 to A6 in FIG. 3 by the router 101 and the route calculation device 200 in the embodiment are performed.
[0076]
Further, in the present embodiment, the router 102 and the route calculation device 202 are connected to the router 101 and the route calculation device 202 as shown by arrows in steps B21 to B26 in FIG. 7 and the router 102 and the route calculation device 202 in FIG. The same operation as that of steps B11 to B16 in FIG. Similarly, the router 103 and the route calculation device 203 are connected to the router 101 and the route calculation device 201 as shown by arrows in steps B31 to B36 in FIG. 7, the same operations as those in Steps B11 to B16 are performed. Here, the processing of these steps B11 to B16 (router 101 & route calculation device 201 side process B10), the processes of steps B21 to B26 (router 102 & route calculation device 202 side process B20), and the processes of steps B31 to B36 The process (process B30 on the router 103 and the route calculation device 203 side) is realized in parallel.
[0077]
As described above, in the route control system based on the OSPF according to the present embodiment, each router individually transmits a copy of the link state database to the route calculation device connected thereto, and calculates the link state database by the route calculation device. The received shortest path set (path table information) is received. Therefore, there is no need to transmit and receive the shortest path set between routers. As a result, the amount of data circulating on the network system can be reduced, and the unique effect of reducing the influence on other communications can be obtained. Further, the effect of reducing the delay until information is registered in the routing table of each router can be obtained at the same time.
[0078]
(3) Third embodiment
[0079]
Based on the above-described OSPF-based route control system according to the first embodiment and the second embodiment, the following OSPF-based route control system according to the third embodiment can be considered.
[0080]
That is, as a third embodiment of the present invention, each router has the components shown in FIG. 1 (link state database 1, route table 2, link state database construction unit 3, link state database transmission unit 4, route table information A receiving unit 5, an inter-router routing table information transmitting unit 6, and an inter-router routing table information receiving unit 7) are provided. Further, as shown in FIG. In the aspect of the first embodiment in which "only one (one) route calculation device is provided in one area", the "specific route calculation device is provided (connected) to each router". An embodiment capable of coping with the aspect of the second embodiment "" can be considered.
[0081]
In this case, for example, in accordance with a request / instruction of the network system to which the present invention is applied, which of the above two modes is used to determine the OSPF-based route control system of the present invention is determined. It will be.
[0082]
(4) Fourth embodiment
[0083]
FIG. 8 is a block diagram showing a configuration of a route control system using OSPF according to the fourth embodiment of the present invention.
[0084]
Referring to FIG. 8, the routing control system based on OSPF according to the fourth embodiment of the present invention is different from the routing control system based on OSPF according to the first embodiment shown in FIG. And a path calculation device program 820.
[0085]
The router program 810 is read by each of the routers (routers 101/102/103), and determines the operation of each of the routers by link state database construction unit 3, link state database transmission unit 4, routing table information reception unit 5, Control is performed as the routing table information transmitting unit 6 and the inter-router routing table information receiving unit 7 (the link status database 1 is constructed by the link status database constructing unit 3, and the routing table information receiving unit 5 or the routing table information between routers is used). The routing table 2 is set by the receiving unit 7). The operation of each router under the control of the router program 810 includes the link state database construction unit 3, link state database transmission unit 4, route table information reception unit 5, route table information between routers in the first embodiment. The operation is exactly the same as the operation of the transmitting unit 6 and the inter-router route table information receiving unit 7, and thus the detailed description is omitted.
[0086]
The route calculation device program 820 is read into the route calculation device 200, and controls the operation of the route calculation device 200 as the link state database receiving unit 8, the shortest route calculating unit 9, and the route table information transmitting unit 10. The operation of each route calculation device under the control of the route calculation device program 820 is performed by the link state database reception unit 8, the shortest route calculation unit 9, and the route table information transmission unit 10 in the route calculation device 200 according to the first embodiment. Since the operation is exactly the same as that described above, a detailed description thereof will be omitted.
[0087]
(5) Fifth embodiment
[0088]
FIG. 9 is a block diagram showing a configuration of a route control system using OSPF according to the fifth embodiment of the present invention.
[0089]
Referring to FIG. 9, the OSPF routing control system according to the fifth embodiment of the present invention is different from the OSPF routing control system according to the second embodiment shown in FIG. And a path calculation device program 920.
[0090]
The router program 910 is read by each router (routers 101/102/103), and controls the operation of each router as the link state database construction unit 3, link state database transmission unit 4, and routing table information reception unit 5. (The link state database 1 is constructed by the link state database construction unit 3, and the routing table 2 is set by the routing table information receiving unit 5). The operation of each router under the control of the router program 910 is exactly the same as the operation of the link state database construction unit 3, link state database transmission unit 4, and routing table information reception unit 5 in each router in the second embodiment. Therefore, the detailed explanation is omitted.
[0091]
The route calculation device program 920 is read by each route calculation device (route calculation device 201/202/203), and the operation of each route calculation device is described by the link state database receiving unit 8, the shortest route calculation unit 9, and the route calculation device. It is controlled as the table information transmitting unit 10. The operation of each route calculating device under the control of the route calculating device program 920 is performed by the link state database receiving unit 8, the shortest route calculating unit 9, and the route table information transmitting unit 10 in each route calculating device in the second embodiment. Since the operation is exactly the same as that described above, a detailed description thereof will be omitted.
[0092]
【The invention's effect】
As described above, according to the present invention, the following effects are produced.
[0093]
The first effect is that the load on the router operating the OSPF can be reduced. As a result, the router can concentrate on the original route control processing, and the processing speed of the router is improved.
[0094]
The reason for this effect is that, in the related art, the router that consumes the most processing capacity “process of calculating the shortest path based on the link state database” is performed by another device (route calculation device), This is because it is sufficient to simply extract information about itself (the shortest path set starting from the shortest path set) from the shortest path set calculated by the device and register the extracted information in the own route table.
[0095]
The second effect is that it is easy to investigate a route control failure in a network system.
[0096]
The reason for this effect is that one route calculation device has all the copies of the routing table that each router belonging to a certain area should have, so that it becomes necessary to investigate the routing table when a routing control failure occurs. This is because, in such a case, it is not necessary to “check the routing tables scattered in a plurality of routers” as in the related art, and it is only necessary to check the routing table information of the route calculation device.
[Brief description of the drawings]
FIG. 1 is a block diagram illustrating a configuration of a path control system based on OSPF according to a first embodiment of the present invention.
FIG. 2 is a diagram showing a configuration of a network system to which the OSPF routing control system shown in FIG. 1 is applied;
FIG. 3 is a flowchart showing processing of the routing control system by the OSPF shown in FIG. 1;
FIG. 4 is a block diagram for explaining a specific operation of the OSPF-based route control system shown in FIG. 1;
FIG. 5 is a block diagram showing a configuration of a route control system using OSPF according to a second embodiment of the present invention.
6 is a diagram showing a configuration of a network system to which the routing control system based on the OSPF shown in FIG. 5 is applied.
FIG. 7 is a flowchart showing a process of the routing control system by the OSPF shown in FIG. 5;
FIG. 8 is a block diagram illustrating a configuration of a route control system using OSPF according to a fourth embodiment of the present invention.
FIG. 9 is a block diagram illustrating a configuration of a route control system using OSPF according to a fifth embodiment of the present invention.
[Explanation of symbols]
1 Link state database
2 routing table
3 Link state database construction section
4 Link state database transmission unit
5 Routing table information receiving unit
6 Route table information transmission section between routers
7 Route table information receiving unit between routers
8 Link state database receiver
9 Shortest path calculator
10 routing table information transmission unit
100 areas
101, 102, 103 router
104, 105, 106 network
200, 201, 202, 203 route calculation device
810,910 Router program
820,920 Program for route calculation device

Claims (8)

In a network system in which path control by OSPF is performed,
As a dedicated device for executing a process of calculating the shortest route based on data indicating the link state, a route calculation device provided separately from the router,
The load on the calculation of the shortest route is removed by the existence of the route calculation device, and the configuration is such that the original route control process can be devoted. By obtaining the calculation result of the route calculation device, the shortest route of the start route itself is obtained. A routing control system based on OSPF, comprising: each router capable of holding a set. In a network system in which path control by OSPF is performed,
A link state database in each router having a data group indicating a link state of all routers and all networks belonging to the area where the own router is located,
A route table in each router holding information indicating the `` own router's shortest path set of the starting point '' calculated based on the link state database,
A link state database constructing unit in each router that has a “function to construct a link state database” in OSPF, and
When the own router is a computing device connection router, a link state database transmitting unit in each router that transmits a copy of the link state database held by the own router to the route calculation device;
When the own router is a router connected to a computing device, the router receives route table information indicating the shortest path set for all routers calculated by the route computing device from the route computing device, and relates to the own router in the received routing table information. A routing table information receiving unit in each router that registers the shortest route set in the routing table in the own router,
An inter-router routing table information transmitting unit in each router for transmitting the remaining routing table information obtained by deleting the shortest path set related to the own router from the routing table information received by the own router to an adjacent router;
An inter-router routing table information receiving unit in each router for receiving routing table information transmitted from an adjacent router and registering a shortest path set for the own router in the received routing table information in the routing table in the own router; When,
A link state database receiving unit that receives a copy of the link state database sent from the computing device connection router, and calculates a shortest path based on the copy of the link state database received by the link state database receiving unit A shortest path calculation unit that generates a shortest path set for all routers, and a path table information transmission unit that transmits path table information indicating the shortest path set calculated and generated by the shortest path calculation unit to a computing device connection router. And a route calculation device provided in one area. When the inter-router routing table information receiving unit performs the process of registering the shortest route set related to the own router in the routing table extracted from the received routing table information, the `` whether the information to be registered has already been registered Check if it is not, and if the check determines that "registered", pass control to the router-to-router routing table information transmission unit without performing the registration process and determine that "not registered" in the check. 3. The OSPF-based route control system according to claim 2, wherein an additional operation of "performing the registration process when determined" is performed. In a network system in which path control by OSPF is performed,
A link state database in each router having a data group indicating a link state of all routers and all networks belonging to the area where the own router is located,
A route table in each router holding information indicating the `` own router's shortest path set of the starting point '' calculated based on the link state database,
A link state database constructing unit in each router that has a “function to construct a link state database” in OSPF, and
A link state database transmitting unit in each router that transmits a copy of the link state database held by the own router to the route calculation device connected to the own router;
Route table information indicating the shortest path set for all routers calculated by the route calculation device connected to the own router is received from the route calculation device connected to the own router, and the route table information in the received route table information is A routing table information receiving unit in each router that registers the shortest route set for the router in the routing table in the own router,
A link state database receiving unit for receiving a copy of the link state database sent from the router, and calculating the shortest path based on the copy of the link state database received by the link state database receiving unit, and calculating A shortest path calculation unit that generates a shortest path set for the router, and a path table information transmission unit that transmits to the router the path table information indicating the shortest path set calculated and generated by the shortest path calculation unit. A path control system based on OSPF, comprising: the path calculation apparatuses provided one by one with respect to each other. In each router, a link state database, a routing table, a link state database construction unit, a link state database transmitting unit, a routing table information receiving unit, an inter-router routing table information transmitting unit, and an inter-router routing table information receiving unit are provided. After a unique route calculation device can be connected to each router, the processing mode of the invention described in claim 2 in which "only one route calculation device is provided in one area", A route control system based on OSPF, which is capable of coping with a mode of processing according to the invention as set forth in claim 4, wherein a unique route calculation device is provided for each. In a network system in which path control by OSPF is performed,
A route calculation device program for causing a route calculation device, which is a dedicated device provided separately from the router, to execute a process of calculating a shortest route based on data indicating a link state;
Each router has a configuration in which the load on the calculation of the shortest route is removed by the presence of the route calculation device, and the router can concentrate on the original route control processing. A router program for causing a set of shortest paths to function so that the set can be held. In a network system in which path control by OSPF is performed,
A link state database in each router that has a data group indicating the link state of all routers and all networks belonging to the area where the own router is located, and a “local router starting point calculated based on the link state database” Assuming that there is a routing table in each router that holds information indicating the shortest route set of
Each router has a "function for constructing a link state database" in OSPF, and a link state database constructing unit for constructing the link state database. A link state database transmitting unit that transmits a copy of the link state database to the path calculation device, and, when the own router is a calculation device connection router, the routing table information indicating the shortest path set for all routers calculated by the path calculation device. A routing table information receiving unit that receives from the routing computer and registers the shortest route set related to the own router in the received routing table information in the routing table in the own router, and relates to the own router based on the routing table information received by the own router. An inter-router routing table that sends the remaining routing table information to the neighboring router after removing the shortest path set A transmission unit, and an inter-router routing table information receiving unit that receives routing table information transmitted from an adjacent router and registers the shortest route set related to the own router in the received routing table information in the routing table in the own router. A program for the router to function as
A path calculation device provided in one area is connected to a link state database receiving unit that receives a copy of the link state database sent from a calculation device connection router, and the link state database receiving unit that receives a copy of the link state database. A shortest path calculation unit that calculates the shortest path based on the copy of the link state database to generate a shortest path set for all routers, and routing table information indicating the shortest path set calculated and generated by the shortest path calculation unit. A route control system based on OSPF, comprising: a route calculation device program for functioning as a routing table information transmission unit to be transmitted to a calculation device connection router. In a network system in which path control by OSPF is performed,
A link state database in each router that has a data group indicating the link state of all routers and all networks belonging to the area where the own router is located, and a “local router starting point calculated based on the link state database” Assuming that there is a routing table in each router that holds information indicating the shortest route set of
Each router has a “function for constructing a link state database” in OSPF, and a link state database construction unit that constructs the link state database, and connects a copy of the link state database of the own router to the own router. A link state database transmitting unit for transmitting to the route calculating device, and routing table information indicating the shortest route set for all routers calculated by the route calculating device connected to the own router, to the route connecting to the own router. A router program for receiving from the computing device and causing the shortest path set for the own router in the received routing table information to function as a routing table information receiving unit for registering in the routing table in the own router;
A path calculation device provided for each of all the routers is received by a link state database receiving section for receiving a copy of the link state database sent from the router, and a link state database receiving section. A shortest path calculation unit that calculates the shortest path based on the copy of the link state database to generate a shortest path set for all routers, and routing table information indicating the shortest path set calculated and generated by the shortest path calculation unit A route calculation device program for causing the router to function as a routing table information transmitting unit that transmits the route control information to a router.

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