JP2008028735A - Route providing apparatus in communication and its route measuring method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a route providing apparatus in a communication and its route measuring method, which are sufficiently utilized for acquiring a position of a node and a route information even in a large scale IP network like Internet. <P>SOLUTION: A route estimating apparatus 10 includes a transmitting and receiving portion 12, a route detecting function portion 14, and a route information storing portion 16, estimates a distance until a communication object, based on a response at a distance estimating function portion 26 of the route detecting function portion 14, verifies a truth-or-falsehood of the estimated distance, examines the route according to the truth-or-falsehood of the distance at a route examining function portion 28, and reduces the number of times remarkably in comparison with the number of times of transmission and reception by the examination by a usual command by storing the route information in the route information storing portion 16 according to examination results. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a route providing apparatus in communication and a route measuring method thereof. In particular, the communication path providing apparatus of the present invention relates to a distance detection apparatus that dynamically detects the position of a node in a communication network and the distance obtained from the communication path. The route measurement method in communication according to the present invention relates to a method for dynamically estimating a distance to a communication partner based on information obtained.

  As a method for collecting network route information, there is a method using “traceroute”. “Traceroute” is a command that can know a sequence of routers that are relay nodes from a certain base point node, that is, a terminal to another node. As disclosed in Patent Document 1, “traceroute” is developed using ICMP (Internet Control Message Protocol) in IP (Internet Protocol) corresponding to the network layer of the OSI (Open Systems Interconnection) basic reference model. Command. “Traceroute” can obtain network connection information as a “tree structure rooted at a base node” by examining routes for a plurality of nodes and integrating the results.

Since this tree structure is based on fixed point observation from the base node, the distance between each node may be different from the distance on the actual network. However, a sufficiently approximate result can be obtained in a network managed by a general routing protocol. Common routing protocols include RIP (Routing Information Protocol), OSPF (Open Shortest Path First), BGP (Broader Gateway Protocol), IS-IS (Intermediate System To Intermediate System), and the like.
JP 2004-208068 A

  “Traceroute” is the easiest and most widely used method for obtaining route information, but has the following problems. First, “traceroute” takes time to perform communication processing (ICMP Echo Request) several times in order to check one route. Second, “traceroute” is not suitable for the purpose of route investigation for a plurality of nodes because it takes time to investigate one route. Third, “traceroute” is a network where dynamic route control is performed, because the route information may change due to the addition of nodes and links, and events such as failures and congestion. However, the acquired information becomes obsolete over time.

  The present invention eliminates the disadvantages of the prior art, and provides a route providing apparatus and a route measuring method for communication that can be sufficiently used for obtaining node position and route information even in a large-scale IP network such as the Internet. The purpose is to provide.

  In order to solve the above-described problems, the present invention provides a route providing apparatus that collects route information by a command based on a protocol of a control message and provides a route with a communication target in a communication network. A transmission / reception means for transmitting a command from a device to a communication target and receiving a response from the communication target for the command, a detection function block for detecting path information, and an information storage means for storing the detected path information. The function block includes an estimation function block that estimates the distance to the communication target based on the response, verifies the truth of the estimated distance, and an investigation function block that investigates the route according to the truth of the distance. The route information is stored in the information storage unit according to the result.

  In order to solve the above-mentioned problem, the present invention is a method for collecting path information by a command based on a control message protocol in a communication network and measuring a path with a communication target. A first step of transmitting a command to the target, receiving a response from the communication target to the command, estimating a distance to the communication target based on the response, and verifying the authenticity of the estimated distance; The second step of investigating the route according to false and the second step detect the route information in the reverse direction to the command detection direction, determine the route information investigated, and route according to the detection of the existing node A third step of storing information, and a fourth step of detecting route information that has been detected in the same direction as the command detection direction, determining the investigated route information, and storing the route information according to the determination result. And

  According to the route providing apparatus and the route measuring method according to the present invention, the estimation function block of the detection function block estimates the distance to the communication target based on the response, verifies the truth of the estimated distance, and the investigation function block By investigating the route according to the authenticity of the distance in, by storing the route information in the information storage means according to the investigation result, the number of times can be significantly reduced compared to the number of times of transmission and reception by the investigation with a normal command, The survey time can be shortened, and when the survey results are accumulated, the amount of surveyed neighboring nodes increases, the effect is increased, the amount of information and the load on route inspection are suppressed, and dynamic route change is performed. It is possible to detect and suppress information obsolescence.

  Next, an embodiment of a route providing apparatus in communication according to the present invention will be described in detail with reference to the accompanying drawings. Referring to FIG. 1, an embodiment of a route providing apparatus in communication according to the present invention includes a transmission / reception unit 12, a route detection function unit 14, and a route information storage unit 16 in a route estimation device 10, and distance estimation of the route detection function unit 14. The function unit 26 estimates the distance to the communication target based on the response, verifies the truth of the estimated distance, the route survey function unit 28 investigates the route according to the truth of the distance, and according to the survey result By storing the route information in the route information storage unit 16, the number of times of transmission / reception can be significantly reduced compared to the number of times of transmission / reception by the normal command investigation, the investigation time can be shortened, and the investigation results are accumulated. As a result, the amount of investigated neighboring nodes is increased, the effect is enhanced, the load on the information amount and the route check is suppressed, the dynamic route change is detected, and the information becomes obsolete.

  The present embodiment is a case where the route providing device in the communication of the present invention is applied to the route estimating device 10. The illustration and description of parts not directly related to the present invention are omitted. In the following description, the signal is indicated by the reference number of the connecting line in which it appears.

  The route estimation apparatus 10 includes a transmission / reception unit 12, a route detection function unit 14, and a route information storage unit 16, as shown in FIG. The transmission / reception unit 12 has a function of connecting the IP network 18 and the route estimation device 10 and transmitting / receiving communication information based on ICMP. The transmission / reception unit 12 is connected to the IP network 18 and is connected to the route detection function unit 14 inside the route estimation device 10. The transmission / reception unit 12 handles information according to the ICMP communication protocol, transmits the information 20 to the communication destination via the IP network 18, and receives the information 20 from the communication destination via the IP network 18. Further, the transmission / reception unit 12 transmits the information 20 received according to the ICMP communication protocol described above to the route detection function unit 14 as information 22, receives the information 22 from the route detection function unit 14, and transmits it as information 20. To do.

  The route detection function unit 14 has a function of detecting a route to a designated terminal device. The route detection function unit 14 transmits / receives information 22 to / from the transmission / reception unit 12. The route detection function unit 14 transmits / receives information 24 to / from the route information storage unit 16. The route detection function unit 14 may pass through the information 24 read from the route information storage unit 16 and supply it to the transmission / reception unit 12 according to circumstances. The route detection function unit 14 includes a distance estimation function unit 26 and a route investigation function unit 28 in order to realize this function.

  The distance estimation function unit 26 has a function of estimating a distance to a terminal device, that is, a node. The distance estimation function unit 26 further includes a distance calculation function unit 30 and a distance verification function unit 32. The distance calculation function unit 30 has a function of estimating and calculating the distance. The distance calculation function unit 30 corresponds to a distance estimation process (SUB1) described later. The distance verification function unit 32 has a function of verifying the authenticity of the calculated distance D. The distance verification function unit 32 corresponds to a distance verification process (SUB2) described later.

  The route investigation function unit 28 has a function of examining, for example, a terminal device designated from the device 10, that is, an intermediate node sequence that is a route to the node. The route investigation function unit 28 includes a reverse order detection function part 34 and a forward order detection function part 36. The reverse order detection function unit 34 and the normal order detection function unit 36 are in a reverse relationship with each other, and examine the node sequence of the direction in each order. The reverse order detection function unit 34 and the normal order detection function unit 36 correspond to a reverse order detection process (SUB3) and a normal order detection process (SUB4) described later, respectively.

  The route information storage unit 16 has a function of storing and storing connection information of the IP network 18. The route information storage unit 16 is a storage.

  Note that the transmission / reception unit 12, the route detection function unit 14, and the route information storage unit 16 in the route estimation device 10 are controlled by a system control unit (not shown).

  Next, an operation when a route to a specific node is investigated by the route estimation device 10 to which the route providing device of the present invention is applied will be described. Here, the specific node is a terminal device, a router, or the like. First, the route estimation device 10 performs distance estimation processing by the route estimation function unit 26. The route estimation device 10 represents the estimated distance from the device 10 to the inspection target node, that is, the number of relay nodes, as a symbol D, and determines (SUB1).

  Next, the authenticity of the distance D determined by the distance verification function unit 32 is verified (SUB2). The verification compares the value of the distance D with the actual distance, and determines whether or not the value of the distance D is the same as or larger than the actual distance. When the value of the distance D is equal to or larger than the actual distance, it is determined to be true. If the distance D is smaller than the actual value, it is determined to be false. After this verification, the process proceeds to true / false judgment (to step S10).

  Next, it is determined whether or not the verification result is true (step S10). If true (YES), proceed to reverse order detection processing (to SUB3). If it is false (NO), the process proceeds to the normal order detection process (to SUB4).

  Next, in the reverse order detection process in the route investigation function unit 28, a route between the node to be inspected and the route estimation device 10 is detected from the position of the distance D-1 toward the route estimation device 10. Since this detection direction is the reverse direction of traceroute, it is called reverse order. After this detection, the route estimation ends. In the normal order detection process, a route between the inspection target node and the route estimation device 10 is detected from the position of the distance D + 1 toward the inspection target node. Since this detection direction is the same direction as traceroute, it is called forward order. After this detection, the process proceeds to the reverse order detection process (to SUB3).

  Next, details of each processing operation executed in the route estimation device 10 will be further described. First, the distance estimation process (SUB1) will be described with reference to FIG. The distance estimation process is a process executed in the distance estimation function unit 30. When the distance estimation process is executed, the maximum number of times (TTL: Time To Live) is set to 255. An ICMP Echo Request message including this set value is created (substep SS10).

  Next, the created ICMP Echo Request message is supplied from the distance estimation function unit 30 to the transmission / reception unit 12 as an ICMP Echo Request message 22. The transmission unit 12 transmits an ICMP Echo Request message 20 to the IP network 18 (substep SS12).

  Next, the response message 20 supplied is received by the transmission / reception unit 12 via the IP network 18. The transmission unit 12 outputs the received response message 20 to the route detection function unit 14 as a response message 22. The distance calculation function unit 30 of the route detection function unit 14 analyzes the response message 22 and determines whether or not the response message 22 is ICMP Echo Reply (substep SS14). When the response message 22 is ICMP Echo Reply (YES), the process proceeds to the distance D calculation process (to sub-step SS16). If the response message 22 is other than ICMP Echo Reply (NO), it is processed as an error, and the process is terminated via the connector A.

  When the response message 22 is ICMP Echo Reply, the distance D is calculated (substep SS16). Calculate the difference between the integer value {255, 128, 64, 32, 16} and the valid number of times (TTL value) set in the received ICMP Echo Reply, and estimate the smallest positive number among these differences Let distance D. The reason for this difference as the estimated distance is that the value of the number of valid times (TTL) of the received ICMP Echo Reply is a value obtained by subtracting the number of routers on the route from the initial value. This is because the effective number (TTL) is a value obtained by subtracting one by one every time it passes through the relay node. In addition, an arbitrary value can be added to the initial value of the effective number of times (TTL). However, it is almost impossible to set values other than the integer values {255, 128, 64}. for example. If any, the integer value is at most one of {32, 16}. Furthermore, for example, it is almost impossible that there are 16 or more relay nodes in the path between any two nodes on the IP network 18, for example.

  The value of the distance D estimated in this way is stored as an argument, and the process proceeds to the verification process (SUB2) via return.

  Next, the procedure of distance verification processing in the route estimation apparatus 10 will be described with reference to FIG. The distance verification process is a process executed by the distance verification function unit 32 in the distance estimation function unit 14. When this distance verification process is executed, first, an ICMP Echo Request message in which the estimated distance D calculated by the distance estimation process (SUB1) is set to the effective number (TTL) is created (substep SS20). Next, the created ICMP Echo Request message 22 is sent to the transmission / reception unit 12 and transmitted from the transmission / reception unit 12 to the IP network 18 (substep SS22).

  Next, the response message 20 supplied is received by the transmission / reception unit 12 via the IP network 18. The transmission unit 12 outputs the received response message 20 to the route detection function unit 14 as a response message 22. The distance verification function unit 32 of the route detection function unit 14 analyzes and determines the supplied response message 22 (substep SS24). If the response message 22 is ICMP Echo Reply by this analysis (YES), the verification result is true. True of the verification result is stored in the argument, and the process proceeds to the true / false determination of FIG. 2 via return (to step S10). If the response message 22 is not ICMP Echo Reply (NO), the process proceeds to the ICMP Time determination process (goes to sub-step SS26).

  Next, it is determined whether ICMP Time exceeds a predetermined value (substep SS26). If ICMP Time exceeds a predetermined value (YES), the verification result is false. If ICMP Time is less than or equal to a predetermined value (NO), it is determined that an error has occurred, and the process is terminated via connector A.

  Next, the procedure of the reverse order detection process in the route estimation apparatus 10 will be described with reference to FIG. The reverse order detection process (SUB3) is a process executed in the route investigation function unit 28. When the reverse order detection process is executed, the estimated distance D calculated in the distance estimation process (SUB1) is set to the effective number (TTL) (substep SS30).

  Next, an ICMP Echo Request message having a value (TTL-1) obtained by subtracting one value from the valid number (TTL) is created (substep SS32). After creating this message, the process proceeds to a confirmation process (to sub-step SS34).

  In the confirmation process, it is confirmed whether or not the value of the effective number (TTL) is 1 or more (sub-step SS34). When the effective number (TTL) is 1 or more (YES), the reverse order detection function unit 34 sends an ICMP Echo Request message 22 to the transmission / reception unit 12, and the ICMP Echo Request message 22 is sent to the IP network 18 via the transmission / reception unit 12 The process proceeds to a transmission process for transmission as the ICMP Echo Request message 24 (to sub-step SS36). If the effective number (TTL) is smaller than 1 (NO), the process proceeds to the storage process (to sub-step SS38). Next, in the saving process, the route information 24 is registered and saved (substep SS38). After this storage, the reverse order detection process is terminated via a return. In this case, after the reverse order detection process, the distance detection is terminated as shown in FIG.

  Next, the transmission process sends an ICMP Echo Request message 24 to the IP network 18 (substep SS36). After this transmission, the transmission / reception unit 12 receives the supplied response message 20 via the IP network 18. The transmission unit 12 outputs the received response message 20 as the response message 22 to the route investigation function unit 28 (to substep SS40).

  Next, it is determined whether or not the response message 22 received by the reverse order detection function unit 34 in the route investigation function unit 28 is ICMP Echo Reply (substep SS40). If the response message 22 is ICMP Echo Reply (YES), the process returns to the creation of an ICMP Echo Request message having a value (TTL-1) obtained by subtracting the value of the valid count (TTL) by one, and is executed again (sub Step SS32). If the received response message 22 is not ICMP Echo Reply (NO), the process proceeds to the ICMP Time determination process (to sub-step SS42).

  Next, it is determined whether or not the received response message 22 is ICMP Time Exceeded (substep SS42). When the received response message 22 is ICMP Time Exceeded (YES), the process proceeds to a new node detection process (go to sub-step SS44). If the received response message 22 is a message other than ICMP Time Exceeded (NO), it is determined as an error, and the process is terminated via the connector A.

  Next, in the new node detection process, it is confirmed whether or not the node information 24 that has returned ICMP Echo Exceeded is a new node (substep SS44). This confirmation is made by comparing the information 24 with the information registered in the route information storage unit 16. That is, when it is confirmed whether the node has been investigated in the past, if the comparison result does not match (YES), it is determined that the node is a newly discovered terminal, and the process proceeds to the ICMP Echo Request message creation process (substep SS32 What). If there is a node in the information path storage unit 16 (NO), the process proceeds to the storage process (to sub-step SS38).

  Next, storage processing is executed (substep SS38). In the storage process, the path information investigated so far, that is, the sequence of relay nodes is registered in the path information storage unit 16, the process proceeds to return, and the reverse order detection process ends normally.

  Next, the procedure of the normal order detection process in the route estimation apparatus 10 will be described with reference to FIG. The reverse order detection process (SUB4) is a process executed in the route investigation function unit 28. When the reverse order detection process is executed, the estimated distance D calculated in the distance estimation process (SUB1) is set to the effective number (TTL) (substep SS46).

  Next, an ICMP Echo Request message having a value (TTL + 1) obtained by adding one value of the valid number (TTL) is created (substep SS48). After creating this message, the process proceeds to the transmission process (to sub-step SS50).

  Next, in the transmission process, the created ICMP Echo Request message 24 is sent to the IP network 18 (substep SS50). After this transmission, the transmission / reception unit 12 receives the supplied response message 20 via the IP network 18. The transmission unit 12 outputs the received response message 20 to the route investigation function unit 28 as a response message 22 (to substep SS52).

  Next, it is confirmed whether or not the received response message 22 is ICMP Time Exceeded (substep SS52). If the response message 22 is ICMP Time Exceeded (YES), an ICMP Echo Request message having a value (TTL + 1) is returned to the creation process and re-executed. If the response message is not ICMP Time Exceeded (NO), the process proceeds to message determination processing (go to substep SS54).

  Next, the message determination process determines whether or not the response message 22 is an ICMP Echo Reply message (substep SS54). If the response message 22 is an ICMP Echo Reply message (YES), the process proceeds to the storage process (to sub-step SS56). For other messages (NO), the process ends as an error.

  Next, in the storage process, the path information 24 investigated so far, that is, the sequence of relay nodes is registered in the path information storage unit 16, and the normal order detection process is normally terminated via a return.

  Ordinary traceroute investigates the sequence of relay nodes in the order of distance from the observation node itself, that is, from the root of the tree toward the leaves. You will examine the node many times. However, according to the present embodiment, it is possible to investigate relay nodes in the order from the position of the distance D from the observation node to the observation base node, that is, from the leaves of the tree toward the root.

  According to this investigation, when a node that has been investigated in the past is detected in the middle of the investigation, the route has already been found from there, so that the investigation can be omitted. Therefore, it is no longer necessary to investigate neighboring nodes over and over, and the number of ICMP message transmissions / receptions used for route investigation can be significantly reduced compared to ordinary traceroute investigations.

  As described above, such an operation can reduce the number of communication times, shorten the investigation time, further reduce the number of route investigations themselves, and improve the efficiency of the investigation. If the detection results for a plurality of nodes are accumulated, the amount of investigated neighboring nodes also increases, and this effect is further enhanced. From this result, it goes without saying that it can be used effectively for route investigation in a large-scale network.

  Next, another schematic configuration in which the route providing device of the present invention is applied to the route estimation device 10 will be described. As shown in FIG. 7, the route estimation device 10 includes a subnet expansion function unit 38 in the route detection function unit 14 together with the components of the previous embodiment. The subnet expansion function unit 38 has a function of detecting a subnet.

  Next, the operation of the route estimation apparatus 10 will be described. In this operation, a procedure for investigating a route from the device 10 to a specific node will be described with reference to FIG. When the subnet generation processing is executed, the route estimation device 10 includes the address of the node to be investigated in any of the subnets registered in the route information storage unit 16 before the distance estimation processing (SUB1). It is investigated whether or not (step S12).

  Next, it is determined whether the address of the node to be investigated is included in the registered subnet (step S14). If the survey result does not belong to any subnet (NO), proceed to route detection processing (to SUB1). Further, when the investigation result belongs to the subnet (YES), the investigation node is assumed to be in the subnet, shifts to the end without actually investigating the route, and ends.

  Next, in the route detection process, a route is detected (SUB1). After this detection, it is investigated whether the same node or subnet as the previous node of the investigation target node is registered in the route information storage unit 16 as a result of the route investigation (step S16). It is determined whether or not the same node or subnet as the previous node exists in this investigation result (step S18). If it exists (YES), the process proceeds to the minimum size calculation process (to step S20). If the same node as the previous node does not exist (NO), the process proceeds to the end, and the route detection process ends.

  Next, the minimum size calculation processing selects the subnet that has the longest subnet mask length, that is, the smallest subnet size among subnets that include both the investigation target node and the detected node or subnet by the subnet expansion function unit 38. (Step S20). This minimum size is 8 to 32 for IPv4 and 64 to 128 for IPv6.

  Next, the selected subnet is registered in the route information storage unit 16 (step S22). After registration, the path detection process is shifted to end, and ends.

  According to the present embodiment, in addition to the effects of the previous embodiment, since the subnet is a set of terminals different from the previous embodiment, the information size to be managed can be reduced compared to the previous embodiment. . In the previous embodiment, the leaf portion in the path information forming the tree structure manages the node, that is, the terminal. Further, if the investigation target node belongs to any subnet registered in the route information storage unit 16, the investigation can be omitted. Furthermore, as more nodes are investigated, the subnet registered in the path information storage unit 16 gradually becomes larger, and the number of nodes that do not require investigation increases. Therefore, the number of investigations can be greatly reduced as compared with the previous embodiment, and it can be sufficiently used for route investigation in a large-scale network.

  Next, another schematic configuration in which the route providing device of the present invention is applied to the route estimation device 10 will be described. As shown in FIG. 9, the route estimation apparatus 10 includes a subnet reduction function unit 40 in the route detection function unit 14 together with the components of the previous embodiment. The subnet reduction function unit 40 has a function of reducing the size of the subnet.

  Next, the operation of the subnet reduction function unit 40 in the route estimation device 10 will be described. The subnet reduction process in the subnet reduction unit 40 is executed using a user event or a timer event that occurs periodically as a trigger.

  When the subnet reduction process is executed, first, the subnet information stored in the route information storage unit 16 is sequentially searched (step S24). Next, it is determined whether or not all subnet information stored in the path information storage unit 16 has been inspected (step S26). When the inspection of all subnet information is completed (YES), the subnet reduction process is normally terminated. If there is subnet information that has not been examined yet (NO), the subnet information is extracted in order. Thereafter, the process proceeds to a deadline check (to step S26).

  In the time limit check, it is determined whether or not the extracted subnet information has expired (step S28). The expiration is determined by comparing the difference between the creation time or the update time of the subnet information extracted based on a predetermined threshold and the current time. If subnet information having a calculated difference larger than a predetermined threshold is detected (YES), it is determined that a predetermined time or more has passed since the subnet information was generated or updated. Based on this determination, the process proceeds to the distance detection process (to SUB1). If no expiration has been detected (NO), the process returns to the subnet search and repeats the search (to step S24).

  Next, route detection processing is executed (SUB1). This processing is executed for the nodes belonging to the corresponding subnet information, and the route is reexamined. This node is a node that has been investigated in the past.

  Next, it is determined whether or not the previous node has changed (step S30). If the previous node of the subnet has changed as a result of the route reexamination (YES), the process proceeds to the storage process of the route information storage unit 16 (to step S32). As a result of the re-investigation, if the previous node of the subnet is unchanged (NO), the process proceeds to the subnet size reduction process (to step S34).

  Next, the storage processing of the route information storage unit 16 updates the route information obtained by executing the route detection processing, and stores this information (step S32). Thereafter, the process proceeds to a subnet size reduction process (to step S34).

  Next, in the subnet size reduction process, the subnet length in the corresponding subnet information stored in the path information storage unit 16 is increased by one, and the update time of the corresponding subnet information is set to the current time (step S34). In this case, the maximum subnet length is 32 for IPv4 and 128 for IPv6. After this processing, the process returns to the subnet search again (to step S24). By repeating the process in this manner, information is updated with respect to all subnet information stored in the route information storage unit 16.

  In the previous embodiment, the size of the subnet information stored in the path information storage unit 16 is only increased, and once a subnet is registered, the path investigation by ICMP is not performed on the nodes belonging to the subnet. As a result, even if the network connection configuration is changed due to the addition or failure of the network, the change cannot be detected.

  In contrast, in this embodiment, in addition to the effects of the previous embodiment, by operating in this way, when the network connection configuration is changed, the change can be detected, and the size of the subnet is gradually increased with time. Because of the small size, the chances of re-investigation increase gradually, and even in networks where the route is dynamically controlled, the number of re-investigations is reduced while updating the route information to prevent information from becoming obsolete. be able to.

  Services in which the distance on the network affects quality include a VOD (Video On Demand) service, a video conference service, and a PtoP (Point-to-Point) service. Application of the service is effective in determining a server closest to the viewer from among a plurality of VOD servers arranged on the network in the VOD service. Also, the video conference service is effective in selecting a conference server having the smallest dispersion of the distance between a plurality of participants and the server from among a plurality of conference servers arranged on the network. Furthermore, the PtoP service is effective when detecting another user closest to the user or collecting another user within a certain distance from the user.

  The network in the present invention is an IP network in each of the embodiments. However, the present invention is not limited to this, and it goes without saying that the present invention may be applied to a dedicated line and a cable network.

It is a block diagram which shows the schematic structure in the Example of the route estimation apparatus to which the route provision apparatus which concerns on this invention is applied. It is a flowchart explaining the operation | movement of the route detection in the route estimation apparatus of FIG. It is a flowchart explaining the procedure of the distance estimation process in the route detection of FIG. It is a flowchart explaining the procedure of the distance verification process in the path | route detection of FIG. It is a flowchart explaining the procedure of the reverse order detection process in the route detection of FIG. It is a flowchart explaining the procedure of the normal order detection process in the path | route detection of FIG. It is a block diagram which shows the schematic structure in the other Example of the route estimation apparatus to which the route provision apparatus which concerns on this invention is applied. 8 is a flowchart illustrating a procedure for expanding a subnet in the route detection of FIG. 7. It is a block diagram which shows the schematic structure in the other Example of the route estimation apparatus to which the route provision apparatus which concerns on this invention is applied. 10 is a flowchart illustrating a procedure for reducing a subnet in the route detection of FIG. 9.

Explanation of symbols

10 Route estimation device
12 Transceiver
14 Route detection function
16 Route information storage
26 Distance estimation function
28 Route Survey Function Department
30 Distance calculation function
32 Distance verification function
34 Reverse order detection function
36 Forward detection function

Claims (9)

In a communication network, a route providing device that collects route information by a command based on a protocol of a control message and provides a route with a communication target.
Transmitting / receiving means for transmitting the command from the apparatus to the communication target and receiving a response from the communication target to the command;
A detection function block for detecting the route information;
Information storage means for storing the detected route information,
The detection function block estimates a distance to the communication target based on the response, and an estimation function block that verifies the authenticity of the estimated distance;
And a survey function block that investigates a route according to the authenticity of the distance,
A route providing apparatus that stores the route information in the information storage unit according to a survey result.   2. The route providing apparatus according to claim 1, wherein the communication network is an IP (Internet Protocol) network. The apparatus according to claim 1, wherein the estimation function block includes a distance calculation function block that estimates a distance to the communication target based on the response;
And a distance verification function block for verifying the authenticity of the estimated distance. The apparatus according to claim 1, wherein the investigation function block detects in the order opposite to the detection direction of the command, determines the investigated route information, and stores the information in the information storage unit according to detection of an existing node. Reverse order detection function block to be stored;
A route providing apparatus comprising: a normal order detection function block that detects the route information in the same direction as the detection direction of the command, determines the searched route information, and stores the information in the information storage unit according to the determination result.   The apparatus according to claim 1, wherein the detection function block includes an expansion function block for detecting a subnet.   The path providing apparatus according to claim 1, wherein the detection function block includes a reduction function block that reduces a size of a subnet. In a communication network, a method for collecting route information by a command based on a control message protocol and measuring a route with a communication target, the method includes:
Sending the command to the communication target, receiving a response from the communication target to the command,
A first step of estimating a distance to the communication target based on the response and verifying the authenticity of the estimated distance;
A second step of investigating a route according to the authenticity of the distance;
The second step is a third step of detecting in the order opposite to the detection direction of the command, determining the investigated route information, and storing the route information in response to detection of an existing node;
A route measuring method comprising: a fourth step of detecting in the same direction as the command detection direction, determining the investigated route information, and storing the route information according to the determination result.   8. The method according to claim 7, wherein the method includes a fifth step of detecting a subnet.   The method according to claim 7, wherein the method includes a reduction function block for reducing a size of a subnet.

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