JP6739769B2 - Route control system, route control method, and program - Google Patents

Description

The present disclosure relates to a system, a method, and a program for performing route control for flowing traffic to a Disjoint path (an alternative route different from a normal route) discovered in a network.

With the widespread and widespread use of the Internet in the world, network connections have become highly redundant. As a result, it is known that there are many different routes to the destination on the Internet. However, the current Internet typically provides only a single path between the source node and the destination note. If it is possible to freely handle disjoint routes that are different from normal routes and that do not share nodes or links with normal routes, increase the speed and reduce the failure rate due to simultaneous connections of multiple routes, and even prevent failures. Useful for shortening the recovery time. Patent Document 1 and Non-Patent Document 1 disclose research reports on discovery of disjoint routes different from normal routes.

JP, 2010-239426, A

Yuko Tomita, Akihiro Nakao, "A Method of Predicting AS Path Using Incomplete Traceroute Information", IEICE Technical Report. NS, Network System 109 (273), P17-22, 2009-11-05

In Patent Document 1, the path P(I,S) from the intersection node to the transmission source node and the AS (Autonomous System) that the path P(S,I) from the transmission source node to the intersection node pass through are the same. Under the assumption that there is, the information of P(I,S) was used as an alternative to the search of P(S,I). Therefore, in Patent Document 1, there is a possibility that the reverse route may go through an AS different from the forward route, and there is a first problem that an optimal Disjoint path cannot always be obtained.

Further, in Patent Document 1, when the traffic is routed through the discovered Disjoint path, it is necessary to manually confirm whether or not the traffic can be actually routed, and further, the traffic is routed through the Disjoint path. It was necessary to manually configure the network device of In other words, in Patent Document 1, there is a second problem that an operator needs to make an arrangement when passing traffic through the discovered Disjoint path.

Therefore, in order to solve the above problems, the present invention provides a route control system, a route control method, and a program capable of obtaining an optimum Disjoint path and automatically allowing traffic to pass through the Disjoint path. The purpose is to

In order to achieve the above object, the route control system according to the present invention checks whether or not the reverse route can be reached under the same conditions as the forward route in the disjoint path discovered by the route search system.

Specifically, the route control system according to the present invention,
Based on the route information collected from multiple routers on the network, for each pair of routers, calculate the intersection node where the route from one router to the source node and the route from the other router to the destination node intersect A receiving unit that receives a search result in which an alternative route from the transmission source node to the destination node is relayed through the intersection node,
Reverse route confirmation using the search result received by the receiving unit to confirm that a forward route from the transmission source node to the intersection node and a reverse route from the intersection node to the transmission source node are the same. Department,
Equipped with.

Further, the route control method according to the present invention,
Based on the route information collected from multiple routers on the network, for each pair of routers, calculate the intersection node where the route from one router to the source node and the route from the other router to the destination node intersect And a receiving procedure for receiving a search result in which an alternative route from the source node to the destination node via the intersection node is searched,
Reverse route confirmation using the search result received in the receiving procedure to confirm that the forward route from the source node to the intersection node and the reverse route from the intersection node to the source node are the same Procedure and
I do.

In the present invention, it is confirmed that the reverse route and the forward route have the same AS, and then the disjoint path is set. Therefore, the present invention can obtain the optimum Disjoint path, and can solve the first problem.

The route control system according to the present invention,
A route control function confirmation unit for confirming the presence or absence of a route control function for realizing the connection of the alternative route at the intersection node;
A route control function placement unit that places a software route control function on the intersection node in which the route control function can be placed, which is confirmed by the route control function check unit without the route control function,
A route control setting input unit that performs setting for connecting the alternative route to the intersection node in which the route control function is arranged;
Is further provided.

Further, the route control method according to the present invention,
A route control function confirmation procedure for confirming the presence or absence of a route control function for realizing the connection of the alternative route at the intersection node,
A route control function placement procedure of placing a software route control function to the intersection node capable of placing the route control function, which is confirmed in the route control function confirmation procedure without the route control function,
A route control setting input procedure for performing a setting for connecting the alternative route to the intersection node in which the route control function is arranged;
Do more.

The route control function confirmation unit checks whether or not the route control is possible at the intersection node, and if necessary and possible, the route control function placement unit places the route control function at the intersection node, and the route control setting input unit connects the disjoint path. Input the settings required for route control. Therefore, according to the present invention, the traffic can be automatically passed through the disjoint path, and the second problem can be solved.

The route control system according to the present invention may generate an error when the route control function confirmation unit confirms that the route control function cannot be arranged in the intersection node without the route control function. Good.

A program according to the present invention is a program for causing a computer to function as the route control device. The route control system according to the present invention can be realized by a computer and a program, and the program can be recorded in a recording medium or provided through a network.

INDUSTRIAL APPLICABILITY The present invention can provide a route control system, a route control method, and a program capable of obtaining an optimum Disjoint path and automatically allowing traffic to pass through the Disjoint path.

It is a figure explaining the network apparatus contained in the internet. It is a figure explaining the route control system which concerns on this invention. It is a flow chart explaining the route control method concerning the present invention.

Embodiments of the present invention will be described with reference to the accompanying drawings. The embodiments described below are examples of the present invention, and the present invention is not limited to the following embodiments. In addition, in the present specification and the drawings, components having the same reference numerals indicate the same components.

FIG. 1 is a diagram for explaining the Internet 100 that is route-controlled by the route control system of this embodiment. On the Internet 100, a traffic transmission source terminal S, an original traffic destination terminal D, a router RI that is an intersection node discovered by the Disjoint path discovery method, and a router Rs that controls the route of traffic transmitted by the transmission source terminal S. , And a router Rd that controls the route of traffic to the destination terminal D, and other routers Ri and Rj.

The normal traffic route from the source terminal S to the destination terminal D is S-Rs-Rd-D. On the other hand, there is a case where it is desired to form an alternative route (Disjoint path) different from the normal route for the purpose of improving the speed, reducing the failure rate, and shortening the failure recovery time by simultaneously connecting a plurality of routes. In such a case, it is possible to find a route such as a S-Rs-RI-Rd-D disjoint path by using the technique of Patent Document 1.

FIG. 2 is a diagram for explaining the route control system 300 of this embodiment. The route control system 300 is
Based on the route information collected from a plurality of routers on the network 100, the route from one router Rj to the source node S and the route from the other router Ri to the destination node D intersect for each pair of routers. And a receiving unit 31 that receives a search result in which an alternative node (Disjoint path) from the transmission source node S to the destination node D via the intersection node RI is calculated.
31 Reverse route confirmation using the search result received by the receiving unit to confirm that the forward route from the source node S to the intersection node RI and the reverse route from the intersection node RI to the source node S are the same Part 32,
Equipped with.

The route search system 200 uses the technique described in Patent Document 1, and based on the route information collected from a plurality of routers on the network 100, from one router Rj to the source node S for each pair of routers. An intersection node RI that intersects the path from the other router Ri to the destination node D is calculated, and an alternative path (Disjoint path) from the transmission source node S to the destination node D through the intersection node RI is calculated. Outputs the searched search result.

The reverse route confirming unit 32 determines that the reverse route P(I,S) from the intersection node RI to the transmission source node S is the forward route P(S,I) from the transmission source node S to the intersection node RI in the Disjoint path of the search result. It is checked whether or not it is reachable under the same condition as () (the same AS and router are passed through). For example, a traceroute (command for displaying a list of network routes) is executed from the node Rs to the node RI, and from the node RI to the node Rs, and the router and AS that go through the reverse route P(I,S) are ordered. It is confirmed whether the router and AS passing through the route P(S,I) are the same. By this confirmation, it becomes possible to evaluate the characteristics such as the delay of the discovered Disjoint path.

In Patent Document 1, P(I,S) information is used as an alternative to the search for P(S,I) under the assumption that P(I,S) and AS passing through P(S,I) are the same. Since it was used, there is a possibility that the reverse route may go through an AS different from the forward route, and there is a possibility that the optimum Disjoint path cannot be obtained. However, in the route control system 300, the reverse route confirmation unit 32 has P(S,I) corresponding to P(I,S), and P(I,S) and P(S,I) pass through. It is possible to confirm that the routers and AS are the same and that the transmission delay times of P(I,S) and P(S,I) are similar.

As shown in FIG. 2, the reverse route confirmation unit 32 receives the search result (P(S, I, D) information of the disjoint path transmitted by the route search system of Patent Document 1) from the route search system 200, and confirms the above. Alternatively, the configuration may be such that it is incorporated into the route search system 200. In the latter case, the confirmed search result of the reverse route confirmation unit 32 is transmitted to the route control function confirmation unit 33 described later.

The route control system 300 is
A route control function confirming unit 33 for confirming the presence or absence of a route control function for realizing the connection of the alternative route at the intersection node RI,
A route control function placement unit 34 that places the software route control function on the intersection node RI where the route control function can be placed, which is confirmed by the route control function checking unit 33 without the route control function,
A route control setting input unit 35 that performs setting for connecting the alternative route to the intersection node RI in which the route control function is arranged;
Is further provided.

The route control function confirming unit 33 confirms whether or not the intersection node RI has a route control function or the like for realizing the connection of the Disjoint path (control by rewriting the header of the packet). The route control function is, for example, a function like Openflow. In Openflow, traffic can be identified as a flow from the IP address or MAC address of the transmission source, and processing such as rewriting the packet header of a specific flow can be executed. For this, information on the intersection node RI may be held in advance in a DB or the like and confirmed, or an inquiry may be made to the management system that manages the intersection node RI.

When the intersection node RI does not have the route control function, the route control function confirmation unit 33 confirms whether the intersection node RI can arrange the route control function. For example, when the router function is implemented in the intersection node RI by software and the intersection node RI is a server, or when the location where the intersection node RI is set has a colocation server, the route control function confirmation unit 33 It is confirmed whether the software Openflow function or the like can be arranged at the intersection node RI. For this, information of the intersection node RI may be held in advance in a DB or the like, and the information may be confirmed, or an inquiry may be made to the management system that manages the intersection node RI.

When the route control function confirmation unit 33 confirms that the intersection node RI does not have the route control function and the route control function cannot be arranged, an error occurs. If the route control is impossible and the route control function cannot be arranged, an error occurs because the Disjoint path cannot be used. At this time, the processing may be restarted by using another Disjoint path, or may be ended due to an error.

The route control function placement unit 34 places the software route control function in the case where there is no route control function and there is a placeable collocation server or the like. Specifically, when the intersection control router RI does not have a route control function and the route control function can be arranged in the intersection router RI or another node, the route control function arrangement unit 34 determines that the intersection control router 33 has the intersection control unit 33. Since information such as the address of the router RI and other nodes is notified, the software route control function is arranged in the intersection router RI and other nodes. For example, the route control function placement unit 34 transfers/copies software having the Openflow function to the intersection router RI or another node and installs it.

The specific work performed by the route control function confirmation unit 33 and the route control function placement unit 34 is as follows.
(1) It is confirmed whether the traffic from the source node S to the destination node D can be transmitted to the intersection node RI.
(2) When the traffic from the transmission source node S to the destination node D cannot be transmitted to the intersection node RI, the route control function confirmation unit 33 uses a router or the like (Rs in FIG. 1) through which the traffic is transmitted. ) Check if the route can be controlled by the above method.
(3) When the traffic from the source node S to the destination node D cannot be transmitted to the intersection node RI and the router Rs does not have the route control function, the route control function confirmation unit 33 controls the route to the router Rs. Confirm whether the function can be arranged by the above method.
(4) When the traffic from the source node S to the destination node D cannot be transmitted to the intersection node RI, the router Rs cannot control the route, and the route control function cannot be arranged in the router Rs, the Disjoint path is An error occurs because it cannot be used.

The route control setting input unit 35 gives an instruction to rewrite the header information of the packet in order to connect the disjoint path. When the route control function confirming unit 33 and the route control function arranging unit 34 can set the route to the intersection node RI or the router Rs, the route control setting input unit 35 can set the route to the intersection node RI or the router Rs. And information such as its address is transmitted.

The route control setting input unit 35 arrives at the router Rs when the traffic from the source node S to the destination node D cannot be transmitted to the intersection node RI and the route control is possible at the router Rs. The destination of the traffic from the transmission source node S is the intersection node RI, and the setting is input so as to be transmitted to the route for the intersection node RI. For example, a flow in which the source IP of the packet arriving as the Openflow flow is the source node S and the destination IP is the destination node D, the destination IP of the flow is rewritten to the intersection node RI, and is transmitted from the port for the intersection node RI. Put in the rules.

Further, the route control setting input unit 35 inputs settings so that the traffic destination from the transmission source node S that has arrived at the intersection node RI is sent to the route for the destination node D as the destination node D. For example, a flow in which the source IP of a packet arriving as an Openflow flow is the source node S and the destination IP is the intersection node RI is rewritten to the destination node D, and is transmitted from the port for the destination node D. Put in the rules.

The traffic transmitted from the source node S to the destination node D reaches the router Rd via the intersection node RI and is transferred to the destination node D by the setting performed by the route control setting input unit 35. Therefore, the traffic can use the route of S-Rs-RI-Rd-D, which is the disjoint path, instead of the normal route of S-Rs-Rd-D.

FIG. 3 is a flowchart illustrating a route control method performed by the route control system 300.
In this route control method, first, based on the route information collected from a plurality of routers on the network 100, a route from one router Rj to the source node S and a destination from the other router Ri for each pair of routers. An intersection node RI that intersects the route to the node D is calculated, and an alternative route from the transmission source node S to the intersection node RI to the destination node D is searched. (Step S01).
Then, using the search result received in the receiving procedure, it is confirmed that the forward route from the transmission source node S to the intersection node RI and the reverse route from the intersection node RI to the transmission source node S are the same. A reverse route confirmation procedure is performed (step S20).

When the forward route and the reverse route are the same, the route control function confirmation procedure for confirming the presence or absence of the route control function for realizing the connection of the alternative route at the intersection node RI is performed (step S02).
If the intersection node RI does not have a route control function and the route control function can be arranged, the route control function placement procedure for placing the software route control function on the intersection node RI is performed (steps S03, S07, S08). On the other hand, when the intersection node RI does not have the route control function and the route control function cannot be arranged, an error occurs and the process ends (step S13).
If the intersection node RI has a route control function, or if the intersection node RI can be provided with a software route control function, it is confirmed whether or not it is possible to transmit a draft from the source node S to the intersection node RI (step S04). A route control setting input procedure for setting the node for connecting the alternative route is performed (steps S05 and S06).

On the other hand, when the traffic cannot be transmitted from the transmission source node S to the intersection node RI, the routing control function that sets the destination of the packet transmitted from the transmission source node S as the intersection node RI changes from the transmission source node S to the destination node D. It is confirmed whether it exists in the normal route (step S09). If it does not exist, it is confirmed whether the route control function can be arranged in the router Rs (step S11). If it cannot be installed, an error occurs and the process is terminated (step S13). A route control function is arranged (step S12). Then, when the route control function exists on the normal route or when the route control function can be arranged in the router Rs, the destination of the traffic from the source node S is set to the intersection node on the normal route or the route control function of the router Rs. The RI is set to be transmitted to the route for the intersection node RI (step S10). After performing step S10, step S11 is performed.

[effect]
The following effects can be obtained by the route control system 300.
(1) It becomes possible to automatically confirm whether or not it is possible to actually send traffic to the searched Disjoint path.
(2) It is possible to automatically check the presence or absence of the route control function necessary for flowing the traffic to the disjoint path.
(3) It is possible to automatically arrange a route control function required for flowing traffic to the disjoint path.
(4) It is possible to automatically input the route control setting for flowing the traffic to the disjoint path.
(5) With these functions, it is possible to easily perform communication using the disjoint path.

31: receiving unit 32: reverse route confirmation unit 33: route control function confirmation unit 34: route control function placement unit 35: route control function setting input unit 100: Internet 200: route search system 300: route control system

Claims (6)

Based on the route information collected from multiple routers on the network, for each pair of routers, calculate the intersection node where the route from one router to the source node and the route from the other router to the destination node intersect A receiving unit that receives a search result in which an alternative route from the transmission source node to the destination node is relayed through the intersection node,
Reverse route confirmation using the search result received by the receiving unit to confirm that a forward route from the transmission source node to the intersection node and a reverse route from the intersection node to the transmission source node are the same. Department,
A route control system comprising: A route control function confirmation unit for confirming the presence or absence of a route control function for realizing the connection of the alternative route at the intersection node;
A route control function placement unit that places a software route control function on the intersection node in which the route control function can be placed, which is confirmed by the route control function check unit without the route control function,
A route control setting input unit that performs setting for connecting the alternative route to the intersection node in which the route control function is arranged;
The route control system according to claim 1, further comprising: The route control according to claim 2, wherein an error is generated when the route control function confirmation unit confirms that the route control function cannot be arranged in the intersection node without the route control function. system. Based on the route information collected from multiple routers on the network, for each pair of routers, calculate the intersection node where the route from one router to the source node and the route from the other router to the destination node intersect And a receiving procedure for receiving a search result in which an alternative route from the source node to the destination node via the intersection node is searched,
Reverse route confirmation using the search result received in the receiving procedure to confirm that the forward route from the source node to the intersection node and the reverse route from the intersection node to the source node are the same Procedure and
A route control method comprising: A route control function confirmation procedure for confirming the presence or absence of a route control function for realizing the connection of the alternative route at the intersection node,
A route control function placement procedure of placing a software route control function to the intersection node capable of placing the route control function, which is confirmed in the route control function confirmation procedure without the route control function,
A route control setting input procedure for performing a setting for connecting the alternative route to the intersection node in which the route control function is arranged;
The method according to claim 4, further comprising: A program for causing a computer to function as the route control device according to claim 1.

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