WO2023233606A1 - Delay time measurement device, delay time measurement method and delay time measurement program - Google Patents

Delay time measurement device, delay time measurement method and delay time measurement program Download PDF

Info

Publication number
WO2023233606A1
WO2023233606A1 PCT/JP2022/022410 JP2022022410W WO2023233606A1 WO 2023233606 A1 WO2023233606 A1 WO 2023233606A1 JP 2022022410 W JP2022022410 W JP 2022022410W WO 2023233606 A1 WO2023233606 A1 WO 2023233606A1
Authority
WO
WIPO (PCT)
Prior art keywords
delay time
measurement
section
router
route
Prior art date
Application number
PCT/JP2022/022410
Other languages
French (fr)
Japanese (ja)
Inventor
一真 上醉尾
賢 高橋
拓 木原
Original Assignee
日本電信電話株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 日本電信電話株式会社 filed Critical 日本電信電話株式会社
Priority to PCT/JP2022/022410 priority Critical patent/WO2023233606A1/en
Publication of WO2023233606A1 publication Critical patent/WO2023233606A1/en

Links

Images

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L43/00—Arrangements for monitoring or testing data switching networks
    • H04L43/08—Monitoring or testing based on specific metrics, e.g. QoS, energy consumption or environmental parameters
    • H04L43/0852—Delays

Definitions

  • the present invention relates to a delay time measuring device, a delay time measuring method, and a delay time measuring program that record the work time when maintenance work is performed.
  • Non-Patent Document 1 describes a H/W processing unit that stamps time stamps when transmitting and receiving probe packets, and S/W processing that collects NW information, calculates delay measurement routes, generates probe packets, and calculates delay times.
  • a delay measurement system is disclosed. This delay measurement system uses a technique (delay measurement route control method) that measures the delay time for each link by using packets (SRT packets) that travel back and forth to a certain device on the same route up and down.
  • Hiroki Mori 4 others, “Proposal of a delay measurement system that measures delay time in a network with high precision,” IEICE Technical Report, vol. 119, no. 460, NS2019-231, pp. 301-306, 2020 March.
  • Non-Patent Document 1 Since the packet used in Non-Patent Document 1 specifies a label for passing through an arbitrary route using a traffic engineering mechanism, the amount of label information specified increases according to the number of forwarding nodes passed through. In the technique of Non-Patent Document 1, a route is specified so that measurement packets travel back and forth on the same route in order to measure round trip time (RTT). Therefore, if the number of relay points in the measurement section increases by one, the number of measurement routes increases by two, an outbound route and a return route.
  • RTT round trip time
  • Non-Patent Document 1 when the measurement interval becomes long in a large-scale network, there is a high possibility that the specifications of the router will be exceeded. In particular, if the number of labels specifying a route exceeds the router's limit, it may have a negative effect on the router and cause failures or malfunctions, making it impossible to implement the system.
  • the present invention has been made to solve such problems, and provides a delay time measuring device and a delay time measuring device capable of measuring forward delay time or reverse delay time without packets having to travel back and forth between measurement sections.
  • the purpose of this invention is to provide a time measurement method and a delay time measurement program.
  • the present invention is a delay time measuring device that measures a packet delay time occurring in a measurement section between a starting point node and a destination node, and the delay time measuring device measures a packet delay time occurring in a measurement section between a starting point node and a destination node.
  • a first delay time measurement section that measures the round trip delay time that occurs between the device itself and the end point node without passing through the measurement section; and a second delay time measurement section that measures the round trip delay time that occurs between the own device and the destination node without passing through the measurement section.
  • a third delay time for measuring either or both of the forward delay time of a loop returning from the self-device to the self-device via the measurement section and the backward delay time of returning through the loop in the opposite direction.
  • the method is characterized by comprising a delay time calculation section that calculates a backward delay time of the measurement section by subtracting the delay time.
  • forward delay time or reverse delay time can be measured without the packet traveling back and forth in the measurement section.
  • FIG. 1 is a configuration diagram of a delay time measuring device according to a first embodiment of the present invention. It is a flowchart (1) executed by the control unit of the delay time measuring device. It is a flowchart (2) executed by the control unit of the delay time measuring device.
  • FIG. 1 is a conceptual diagram (1) for understanding network topology. It is a flowchart (3) executed by the control unit of the delay time measuring device.
  • FIG. 2 is a conceptual diagram (2) for understanding network topology.
  • FIG. 3 is a diagram showing a return measurement route from a starting point node to an ending point node.
  • FIG. 3 is a diagram showing a loop measurement path passing through a start point node and an end point node.
  • FIG. 1 is a configuration diagram of a delay time measuring device according to a first embodiment of the present invention. It is a flowchart (1) executed by the control unit of the delay time measuring device. It is a flowchart (2) executed by the control unit of the delay time measuring device.
  • FIG. 1 is
  • FIG. 3 is a conceptual diagram when reducing the number of labels embedded in a measurement packet.
  • FIG. 3 is a diagram showing labels embedded in measurement packets.
  • FIG. 7 is a conceptual diagram when deleting a label of an intermediate route when the label upper limit is exceeded.
  • FIG. 3 is a conceptual diagram of measuring delay time of a return measurement route.
  • FIG. 3 is a conceptual diagram of measuring delay time of a loop measurement path.
  • FIG. 3 is a conceptual diagram when packet loss occurs in a measurement section.
  • FIG. 6 is a conceptual diagram when packet loss occurs on a measurement route other than the measurement section.
  • FIG. 7 is a diagram showing an example of a measurement route when the second embodiment of the present invention is applied to a large-scale network.
  • FIG. 3 is a diagram showing labels embedded in measurement packets.
  • FIG. 7 is a diagram illustrating an example of a measurement route when a comparative example is applied to a large-scale network.
  • FIG. 7 is a diagram showing a label embedded
  • the present embodiment an embodiment of the present invention (hereinafter referred to as "the present embodiment") will be described in detail with reference to the drawings. Note that each figure is merely shown schematically to the extent that the present invention can be fully understood. Further, in each figure, common or similar components are denoted by the same reference numerals, and redundant explanation thereof will be omitted.
  • FIG. 1 is a configuration diagram of a delay time measuring device according to a first embodiment of the present invention.
  • the measurement device 100 sends a measurement packet to the network NW, measures the delay time until the sent measurement packet returns, and calculates the delay in the measurement section from the start point router (start point node) to the end point router (end point node). This is a delay time measurement device that calculates time.
  • the measuring device 100 includes hardware resources such as a control section 10, a communication section 30, a clock 40, a storage section 50, and an operation display section 60.
  • the communication unit 30 is an interface that performs packet communication via a plurality of routers (router A to router F (FIG. 4)) installed in the network NW.
  • the clock 40 measures the reference time of the timestamp stamped on the measurement packet.
  • the storage unit 50 includes a non-volatile storage unit such as a ROM (Read On Memory) and an HDD (Hard Disk Drive), and a volatile storage unit such as a RAM (Random Access Memory).
  • the operation display unit 60 is a touch panel type LED (Light Emitting Diode) display.
  • the control unit 10 is a CPU (central processing unit), and controls the first delay time measurement unit 11, the second delay time measurement unit 12, and the second delay time measurement unit by executing a delay time measurement program stored in the storage unit 50.
  • the functions of the three delay time measurement section 13, one-way average delay time calculation section 14, delay time calculation section 15, packet loss determination section 16, measurement route derivation section 20, and display control section 25 are realized.
  • the display control unit 25 controls the operation display unit 60.
  • the first delay time measurement unit 11 measures the round trip delay time that occurs between the own device and the start node without passing through the measurement section from the start node to the end node.
  • the second delay time measurement unit 12 measures the round trip delay time that occurs between the device itself and the end node without passing through the measurement section from the start node to the end node.
  • the third delay time measuring section 13 includes a forward delay time measuring section 13a and a backward delay time measuring section 13b.
  • the forward delay time measuring unit 13a measures the forward delay time of a loop-shaped route (section measurement route) returning from the own device to the own device via the measurement section.
  • the backward delay time measurement unit 13b measures the backward delay time until the loop path (section measurement path) returns in the opposite direction.
  • the one-way average delay time calculation section 14 includes a first calculation section 14a and a second calculation section 14b, and executes either one of them.
  • the first calculation section 14a calculates the one-way average delay time obtained by dividing the round-trip delay time measured by the first delay time measurement section 11 by 2 and the one-way average delay time obtained by dividing the round-trip delay time measured by the second delay time measurement section 12 by 2.
  • the one-way average delay time is calculated by adding the delay time.
  • the second calculation unit 14b adds the round trip delay time measured by the first delay time measurement unit 11 and the round trip delay time measured by the second delay time measurement unit 12, and divides the added round trip delay time by 2. to calculate the one-way average delay time.
  • the delay time calculation unit 15 subtracts the one-way average delay time from the forward delay time to calculate the measurement interval. Calculate forward delay time. Further, when the third delay time measuring section 13 (reverse delay time measuring section 13b) measures the backward delay time, the one-way average delay time is subtracted from the backward delay time to determine the backward delay time of the measurement section. calculate.
  • the packet loss determination unit 16 measures the round trip delay time using the first delay time measurement unit 11 or the second delay time measurement unit 12, and the forward delay time or reverse delay time measured by the third delay time measurement unit 13. If the measurement packet is not returned, it is determined that there is a packet loss.
  • the measurement route derivation unit 20 derives a measurement route and embeds a label indicating the measurement route in the measurement packet before sending the measurement packet.
  • the measurement route derivation unit 20 includes an information collection unit 21, a topology understanding unit 22, a route derivation unit 23, and a label embedding unit 24.
  • the information collection unit 21 collects information on routers (nodes) existing in the network.
  • the topology grasping unit 22 grasps the configuration (topology) in which the routers to be measured in the network are connected. At this time, the information collection unit 21 records information on adjacent routers and link costs (IGP costs).
  • the route derivation unit 23 derives a communication route based on the link cost.
  • the communication path is, for example, the shortest route from the own device to the start point router (start point node), the shortest path from the own device to the end point router (end point router), and the two shortest paths and the measurement section are connected to form a loop. There is a route.
  • the label embedding unit 24 embeds a label indicating the route derived by the route deriving unit 23 into the measurement packet.
  • the flowchart in FIG. 2 is a flowchart for explaining the operation of the information collection section 21.
  • This flow (SP10) is started at the same time as the power is turned on, and is configured to repeat predetermined processing at regular time intervals (SP11 to SP14).
  • the information collecting unit 21 collects network information from the routers to be measured (routers A to F (FIG. 4)) and control devices (not shown) (SP12). After SP12, the information collection unit 21 determines whether there is a difference from the previous acquisition (SP13).
  • the process returns to SP11 via SP14, and the processes of SP12 and SP13 are repeated.
  • the information collection unit 21 causes the topology understanding unit 22 to perform topology understanding (SP20). Note that when the power is turned on, there is no previously acquired information, so the determination in S13 is "Yes”.
  • FIG. 3 is a flowchart for explaining the operation of the topology understanding unit 22.
  • This flow (SP20) is started when it is determined in SP13 ( Figure 2) that there is a difference from the previous acquisition ("Yes" in SP13), and is executed for the number of routers included in the collected information. , is configured to repeat (SP21 to SP24).
  • the topology understanding unit 22 records information about each router in the storage unit 50 (FIG. 1) (SP22). After SP22, adjacent router information and link cost (IGP (Interior Gateway Protocol) cost) are recorded (SP23). After the processing of SP23, the topology understanding unit 22 returns the processing to SP21 via SP24, and repeats the processing of SP22 and 23 for the number of routers.
  • IGP Interior Gateway Protocol
  • FIG. 4 is a conceptual diagram for understanding network topology.
  • the delay time measurement system S1 is, for example, a measurement device 100 connected to a plurality of (six) routers (router A to router F). Only router B is connected to measuring device 100. Router B is connected to router A, router C, and router E. Here, the route between router B and router A is designated as route BA, the route between router B and router C is designated as route BC, and the route between router B and router E is designated as route BE. Further, router A is connected to router F, and router C is connected to router D.
  • the route between router A and router F is defined as route AF, and the route between router C and router D is defined as route CD. Router F and router D are connected to router E.
  • the route between router D and router E is defined as route DE
  • the route between router E and router F is defined as route EF.
  • the starting point node is router D
  • the ending point node is router F.
  • the measurement section is a section that includes the route DE and the route EF.
  • the nodes (router D, router E, and router F) from the start point node to the end point node are referred to as measurement end points.
  • the link cost (IGP cost) of all routes BA, BC, CD, BE, AF, DE, and EF is set to "1". Note that it is assumed that the link cost between the measuring device 100 and the router B is extremely small.
  • FIG. 5 is a flowchart executed by the control unit of the delay time measuring device. This flow is started independently from FIGS. 2 and 3 before releasing the measurement packet to the network NW (FIG. 1), and repeats the predetermined processing for the measurement end points between SP31 and SP40. (SP31 to SP40).
  • the route derivation unit 23 (FIG. 1) derives a route between the measurement end points (SP32). That is, the route derivation unit 23 derives the route DE and the route EF between the measurement end points (router D, router E, router F).
  • the route deriving unit 23 derives a route from the measuring device 100 to the measurement starting point (router D) (SP33).
  • FIG. 6 is a conceptual diagram for understanding network topology.
  • the topology grasping unit 22 changes the link costs of the measurement sections route DE and route EF from "1" to an extremely large value (for example, 100), and creates a link from the measurement device 100 to the measurement start point (router D). Derive the route with the minimum cost. Thereby, the route derivation unit 23 derives the route (route BC+route CD) without selecting (route BE+route DE).
  • the route derivation unit 23 derives a route from the measurement device 100 to the measurement end point (router F) (SP34). That is, the route derivation unit 23 derives the route (route BA+route AF).
  • the route derivation unit 23 derives a pre-section return measurement route and a section measurement route based on the results from SP32 to SP34 (SP35).
  • the shortest route to the measurement start point is (route BC+route CD) derived at SP33, and the shortest route to the measurement end point is (route BA+route AF) derived at SP34. Therefore, the route deriving unit 23 derives the round trip route (route BC+route CD) (solid line ⁇ in FIG. 7) and the round trip route (route BA+route AF) (dashed line ⁇ in FIG. 7) as the pre-section return measurement route. do.
  • the pre-section return measurement route includes both the shortest round trip route to the measurement start point and the shortest round trip route to the measurement end point, and does not include the route between the measurement end points (SP32).
  • the section measurement route is a combination of the section pre-turnback measurement route and the measurement section.
  • the section measurement route is a loop-shaped route that is a combination of the route BC, the route CD, the route DE, the route EF, the route AF, and the route BA.
  • the dashed-dotted line ⁇ in FIG. 8 is the section measurement route in the forward direction
  • the dashed-double line ⁇ is the section measurement route in the backward direction.
  • the label embedding unit 24 embeds a label that specifies the measurement route into the measurement packet.
  • a measurement packet for a forward loop route (section measurement route ⁇ ) includes "Router B" - "Router C” - “Router D” - “Router E” - “Router F” - “Router A”.
  • - "Router B” and a total of seven labels are embedded (see Figure 10 (before reduction)).
  • the route derivation unit 23 determines whether there is a section where the route is unique even if the label is omitted (SP36). If there is a section where the route will be unique even if the label is omitted ("Yes" in S36), the route derivation unit 23 deletes the label of the device (router) in the section from the measurement route (SP37), and performs processing. Proceed to S38.
  • FIG. 9 is a conceptual diagram when reducing the number of labels embedded in a measurement packet.
  • router E since the route from router D to router F (route DE+route EF) always passes through router E as the shortest route, the route will be unique even if the label "router E" is omitted.
  • FIG. 10 is a diagram showing labels embedded in measurement packets.
  • “Router B” - “Router C” - “Router D” - “Router E” - “Router F” - “Router A” - “Router B” A total of seven labels were embedded in this order, but when “Router E” is deleted, “Router B” - “Router C” - “Router D” - “Router F” - "Router A” - Six labels are embedded in the order of "Router B".
  • the number of labels on the measurement path exceeds the upper limit of the device. If a measurement packet exceeding the upper limit number of labels is sent to the router, there is a possibility that a failure or malfunction will occur. If the number of labels exceeds the device upper limit ("Yes" in SP38), the number of labels is reduced until it becomes less than the label upper limit (SP39), and the processing between SP40 and SP31 is repeated. On the other hand, if the number of labels does not exceed the device upper limit ("No" in SP38), the processing between SP40 and SP31 is repeated.
  • FIG. 11 is a conceptual diagram when a label of an intermediate route is deleted when the label upper limit is exceeded. Seven labels should be embedded in the forward section measurement path ⁇ , but when the upper limit of the number of labels for a router is five, omitting the label for router E is not enough. At this time, it is assumed that the label embedding unit 24 (FIG. 1) omits, for example, embedding the labels of router A and router C. In that case, there is a possibility that the measurement packet passes through the route of router B ⁇ router E ⁇ router D ⁇ router E ⁇ router F ⁇ router E ⁇ router B. In other words, due to label reduction, routes are no longer unique and route duplication occurs. As a result, although the accuracy of measuring delay time decreases, it becomes possible to measure it even in large-scale networks.
  • FIG. 12 is a conceptual diagram of measuring the delay time of the return measurement path.
  • the first delay time measuring unit 11 (FIG. 1) emits a measurement packet in which a label of the section pre-turnback measurement route ⁇ to the start point node (router D) is embedded, and the time it takes to return (start point round trip delay time T ⁇ ) to measure.
  • the second delay time measurement unit 12 (FIG. 1) emits a measurement packet embedded with a label of the pre-section return measurement route ⁇ to the end point node (router F), and the time it takes to return (end point round trip delay time T ⁇ ) to measure.
  • the one-way average delay time calculating section 14 (FIG. 1) calculates the one-way average delay time (T ⁇ +T ⁇ )/2.
  • FIG. 13 is a conceptual diagram of measuring the delay time of a loop measurement path.
  • the forward delay time measuring unit 13a (FIG. 1) of the third delay time measuring unit 13 emits a measurement packet (a measurement packet that passes through the measurement interval) in which the label of the forward section measurement route ⁇ is embedded, and returns the measurement packet. The time it takes for this to occur (forward delay time T ⁇ ) is measured.
  • the backward delay time measuring unit 13b (FIG. 1) emits a measurement packet (a measurement packet that passes through the measurement section) in which a label of the backward section measurement path ⁇ is embedded, and the time it takes for it to return (reverse direction delay). The time T ⁇ ) is measured.
  • the delay time calculation unit 15 (FIG. 1) subtracts the one-way average delay time (T ⁇ +T ⁇ )/2 from the forward delay time T ⁇ to calculate the measurement result.
  • the forward delay time of the section ⁇ T ⁇ (T ⁇ +T ⁇ )/2 ⁇ is calculated.
  • the backward delay time measurement unit 13b measures the backward delay time T ⁇
  • the one-way average delay time (T ⁇ +T ⁇ )/2 is subtracted from the backward delay time T ⁇ to calculate the backward delay time ⁇ T ⁇ (T ⁇ +T ⁇ )/2 ⁇ is calculated.
  • the one-way average delay time (T ⁇ +T ⁇ )/2 75 ⁇ Sec.
  • FIG. 14 is a conceptual diagram when packet loss occurs in the measurement interval.
  • the packet loss determination unit 16 determines the starting point round trip delay time T ⁇ of the section pre-turnback measurement route ⁇ from the measurement device 100 to the measurement start point (router D), and the section pre-turnback measurement route from the measurement device 100 to the measurement end point (router F).
  • T ⁇ of ⁇ the end point round trip delay time T ⁇ of ⁇ can be measured and the measurement packet passing through the measurement section does not return to the measurement device 100, a packet loss has occurred in the measurement section (route DE + route EF). , it is determined.
  • FIG. 15 is a conceptual diagram when packet loss occurs on a measurement route other than the measurement section.
  • the packet loss determination unit 16 (FIG. 1) is unable to measure the delay times T ⁇ and T ⁇ of the pre-section return measurement route ⁇ to the measurement start point (router D) and the pre-section return measurement route ⁇ to the measurement end point (router F). If so, it is determined that there is an abnormality in the path from the measurement device 100 to the measurement section (router D or router F).
  • the measuring device 100 of this embodiment is configured to be able to measure and calculate the delay time of the measurement section (from the starting point node to the ending point node) in the network NW (FIG. 1).
  • the measuring device 100 measures the starting point round trip delay time T ⁇ , the ending point round trip delay time T ⁇ , and either or both of the forward direction delay time T ⁇ and the backward direction delay time T ⁇ of the measurement section, and calculates ⁇ T ⁇ (T ⁇ +T ⁇ ) /2 ⁇ and ⁇ T ⁇ (T ⁇ +T ⁇ )/2 ⁇ or both, the delay time of the measurement interval can be determined.
  • the measuring device 100 has a pre-section return measurement route ⁇ to the measurement start point (router D), a pre-section return measurement route ⁇ to the measurement end point (router F), a section measurement route ⁇ in the forward direction, and a section in the reverse direction.
  • a label indicating the measurement route ⁇ is embedded in the measurement packet. Furthermore, the measuring device 100 omits the label embedded in the measurement packet when the route can be uniquely identified even if a part of the label indicating the router of the measurement route is omitted. Thereby, even when the upper limit number of labels of the router is exceeded, by omitting labels, it is possible to avoid exceeding the upper limit number of labels.
  • the measuring device 100 determines that there is an abnormality in the path from the measuring device 100 to the measurement section (router D or router F) when it is not possible to measure the starting point round trip delay time T ⁇ or the ending point round trip delay time T ⁇ . .
  • FIG. 16 is a second embodiment of the present invention, and is a diagram showing an example of a measurement route when the measurement device is applied to a large-scale network.
  • the delay time measurement system S2 includes a measurement device 100 and a plurality of routers A to J.
  • the measuring device 100 and router A are connected, the router A and routers C, D, E, and F are connected, the router C is connected to routers B, H, etc., and the router D and router Router B, H, etc. are connected, router E is connected to routers B, J, etc., and router F is connected to routers B, J, etc.
  • the measurement section is Router J ⁇ Router E ⁇ Router A ⁇ Router D ⁇ Router H. That is, the starting point node of the measurement section is router J, and the ending point node is router H.
  • the pre-section return measurement route ⁇ is Router A ⁇ Router F ⁇ Router J ⁇ Router F ⁇ Router A.
  • the pre-section return measurement route ⁇ is Router A ⁇ Router C ⁇ Router H ⁇ Router C ⁇ Router A.
  • the forward loop ⁇ is Router A ⁇ Router F ⁇ Router J ⁇ Router E ⁇ Router A ⁇ Router D ⁇ Router H ⁇ Router C ⁇ Router A.
  • the loop ⁇ in the reverse direction is Router A ⁇ Router C ⁇ Router H ⁇ Router D ⁇ Router A ⁇ Router E ⁇ Router J ⁇ Router F ⁇ Router A.
  • the pre-section return measurement routes ⁇ and ⁇ include a node (router A) that specifies the measurement section.
  • FIG. 17 is a diagram showing labels embedded in measurement packets.
  • "Router A” - "Router F” - "Router J” - “Router E” - “Router A” - “Router D” - “Router H” - “Router C” - “Router A” A total of nine labels are embedded in this order.
  • FIG. 18 is a diagram illustrating an example of a measurement route when the comparative example is applied to a large-scale network.
  • the configuration of the delay time measurement system S2 is the same as the delay time measurement system S2 (FIG. 16) of the previous embodiment.
  • the route through which the measurement device 100 passes the measurement packet and the delay time calculation method are different.
  • the measurement device 100 calculates the round trip delay time TE of the measurement path ⁇ from the device to the end node (router H) and the round trip delay time TS of the measurement path ⁇ from the device to the start node (router J).
  • the measurement path ⁇ does not include the measurement section (router J-router E-router A-router D-router H).
  • FIG. 19 is a diagram showing labels embedded in measurement packets in a comparative example.
  • "Router A” - "Router E” - “Router J” - “Router E” - “Router A” - “Router D” - “Router H” - [Router D ] - "Router A” - “Router E” - “Router J” - “Router E” - “Router A” a total of 13 labels are embedded in this order.
  • the number of labels is 13, whereas in the second embodiment, the number of labels is reduced to 9.
  • the measurement route is specified so that the measurement packets reciprocate along the same route. Therefore, when the number of relay points in the measurement section increases by one, the number of labels increases by two for the outbound and return routes of the measurement route.
  • the number of labels indicating the section measurement routes ⁇ and ⁇ also increases by one.
  • the round trip delay time measurement route ⁇ to the starting point node is also changed to the ending point node.
  • the measurement packet does not return on the round trip delay time measurement path ⁇ .
  • the delay time measurement method of the second embodiment even if a packet loss occurs between router E and router J, the measurement packets of loops ⁇ and ⁇ will not be returned, but Since the measurement packets from the measurement routes ⁇ and ⁇ are returned, it can be determined that a packet loss has occurred in the measurement section including routers E and J.
  • a delay time measuring device 100 is a delay time measuring device 100 that measures a packet delay time occurring in a measurement section (section DE+section EF) between a start point node and a destination node, and includes the a first delay time measurement unit (11) that measures a round trip delay time (T ⁇ ) occurring between the own device and the start point node (router D) without passing through the measurement section; a second delay time measurement unit (12) that measures the round trip delay time (T ⁇ ) occurring between the own device and the end point node (router F); a third delay time measurement unit (13 ), the first round trip delay time (T ⁇ ) measured by the first delay time measuring unit (11), and the second round trip delay time (T ⁇ ) measured by the second delay time measuring unit A one-way average delay time calculation unit ((T ⁇ +T ⁇ )/2 ⁇ that calculates the one-way average delay time ⁇ (T ⁇ +T ⁇ )
  • the one-way delay time is calculated by subtracting the forward delay time of the measurement section. It is characterized by comprising a delay time calculation unit (15) that calculates the backward delay time of the measurement section by subtracting the average delay time ⁇ (T ⁇ +T ⁇ )/2 ⁇ .
  • one or both of the forward delay time and the reverse delay time in the measurement section can be measured without the packet traveling back and forth in the measurement section. Therefore, even if the number of relay nodes that relay the measurement section increases by one, the number of relay nodes that relay the measurement path on which the third delay time measuring section measures the delay time also increases by one.
  • the first delay time measuring unit (11) and the second delay time measuring unit (12) it is also possible to pass through a node that specifies the section (for example, router A connected to the own device).
  • the section for example, router A connected to the own device.
  • the route from the own device to the start point node and the route from the own device to the end point node need to be different from the measurement section, but the nodes may be common. Thereby, nodes connected to the own device can be included in the measurement section.
  • the present invention is also characterized by further comprising a label embedding unit (24) that embeds a plurality of labels into the packet, omitting the label of the node for which the shortest path is unique.
  • a label embedding unit (24) that embeds a plurality of labels into the packet, omitting the label of the node for which the shortest path is unique.
  • a packet loss determination unit (16) that determines a packet loss when the round trip delay time (T ⁇ , T ⁇ ) cannot be measured by the first delay time measurement unit (11) or the second delay time measurement unit (12); It is characterized by further comprising: According to this, it is possible to determine a packet loss that has occurred between the own device and the start point node or between the own device and the end point node. In other words, if the forward delay time (T ⁇ ) or the reverse delay time (T ⁇ ) can be measured, it means that packet loss has occurred outside the measurement period.
  • the one-way average delay time calculation unit (14) calculates the one-way average delay time (T ⁇ /2) obtained by dividing the round trip delay time (T ⁇ ) measured by the first delay time measurement unit (11) by 2, and the one-way average delay time (T ⁇ /2). 2.
  • a first calculation (calculation of the first calculation unit 14a) that adds the round trip delay time (T ⁇ ) measured by the delay time measurement unit (12) to the one-way average delay time (T ⁇ /2) divided by 2;
  • the round trip delay time (T ⁇ ) measured by the first delay time measurement unit (12) and the round trip delay time (T ⁇ ) measured by the second delay time measurement unit (12) are added to obtain the added round trip delay time.
  • the second calculation is to divide by 2 and calculate the one-way average delay time ⁇ (T ⁇ +T ⁇ )/2 ⁇ .
  • the one-way average delay time ⁇ (T ⁇ +T ⁇ )/2 ⁇ can be calculated from the round trip delay time (T ⁇ , T ⁇ ).
  • Control section 11 First delay time measurement section 12 Second delay time measurement section 13 Third delay time measurement section 13a Forward delay time measurement section 13b Reverse delay time measurement section 14
  • One-way average delay time calculation section 14a First calculation section 14b Second calculation unit 15
  • Delay time calculation unit 16 Packet loss determination unit 20 Measurement route derivation unit 23 Route derivation unit 24 Label embedding unit 100 Measuring device (delay time measuring device)

Landscapes

  • Engineering & Computer Science (AREA)
  • Environmental & Geological Engineering (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Data Exchanges In Wide-Area Networks (AREA)

Abstract

This delay time measurement device comprises: a first delay time measurement unit (11) that measures a round-trip delay time occurring between the device and a start node; a second delay time measurement unit (12) that measures a round-trip delay time occurring between the device and a destination node; a third delay time measurement unit that measures a forward delay time of a loop from the device through a measurement section back to the device; a one-way average delay time calculation unit (14) that calculates a one-way average delay time on the basis of the round-trip delay times measured by the first delay time measurement unit (11) and the second delay time measurement unit; and a delay time calculation unit (15) that subtracts the one-way average delay time from the forward delay time to calculate a forward delay time of the measurement section.

Description

遅延時間測定装置、遅延時間測定方法および遅延時間測定プログラムDelay time measurement device, delay time measurement method, and delay time measurement program
　本発明は、保守作業を行った作業時刻を記録する遅延時間測定装置、遅延時間測定方法および遅延時間測定プログラムに関する。 The present invention relates to a delay time measuring device, a delay time measuring method, and a delay time measuring program that record the work time when maintenance work is performed.
　５Ｇやe-sport等、リアルタイム性が求められるサービスの普及に伴い、ネットワークに対する要件として帯域だけでなく低遅延が求められている。そのため、より短時間、かつ高精度に遅延時間を取得し，サービス品質を確認する手法が求められている。 With the spread of services that require real-time performance, such as 5G and e-sport, network requirements include not only bandwidth but also low latency. Therefore, there is a need for a method to more accurately obtain delay times in a shorter time and to check service quality.
　非特許文献１には、プローブパケットの送受信時にタイムスタンプの打刻を行うＨ/Ｗ処理部とＮＷ情報の収集や遅延測定経路の計算，プローブパケットの生成，遅延時間計算を行うＳ／Ｗ処理部で構成された遅延測定システムが開示されている。この遅延測定システムでは、ある装置までを上下同一経路で往復するパケット(SRTパケット)を用いることでリンク毎の遅延時間の測定を行う技術（遅延測定経路制御方式）を用いている。 Non-Patent Document 1 describes a H/W processing unit that stamps time stamps when transmitting and receiving probe packets, and S/W processing that collects NW information, calculates delay measurement routes, generates probe packets, and calculates delay times. A delay measurement system is disclosed. This delay measurement system uses a technique (delay measurement route control method) that measures the delay time for each link by using packets (SRT packets) that travel back and forth to a certain device on the same route up and down.
　非特許文献1で使用されるパケットは、トラフィックエンジニアリングの仕組みにより任意経路を通るためのラベルを指定するため、経由する転送ノードの数に応じて指定するラベル情報も増加するものである。非特許文献1の技術では、往復遅延時間（ＲＴＴ：Round Trip Time）を測定するために測定パケットが同じ経路を往復するように経路を指定している。そのため、測定区間の中継地点が一つ増えると測定経路は往路、復路の二つ分増加してしまう。 Since the packet used in Non-Patent Document 1 specifies a label for passing through an arbitrary route using a traffic engineering mechanism, the amount of label information specified increases according to the number of forwarding nodes passed through. In the technique of Non-Patent Document 1, a route is specified so that measurement packets travel back and forth on the same route in order to measure round trip time (RTT). Therefore, if the number of relay points in the measurement section increases by one, the number of measurement routes increases by two, an outbound route and a return route.
　また、パケットを中継するルータには、ＳＲ（Segment Routing）で指定できる中継地点数に上限があることが一般的である。非特許文献1の技術では、大規模ネットワークで測定区間が長くなった場合には、ルータの諸元を超過する可能性が高くなる。特に、経路を指定するラベルの数がルータの制限を超過した場合にはルータに悪影響を与えて故障や不具合を誘発する可能性があり、システムを導入することができない。 Additionally, for routers that relay packets, there is generally an upper limit to the number of relay points that can be specified by SR (Segment Routing). In the technique of Non-Patent Document 1, when the measurement interval becomes long in a large-scale network, there is a high possibility that the specifications of the router will be exceeded. In particular, if the number of labels specifying a route exceeds the router's limit, it may have a negative effect on the router and cause failures or malfunctions, making it impossible to implement the system.
　本発明は、このような問題点を解決するためになされたものであり、パケットが測定区間を往復することなく順方向遅延時間または逆方向遅延時間を測定することができる遅延時間測定装置、遅延時間測定方法および遅延時間測定プログラムを提供することを目的とする。 The present invention has been made to solve such problems, and provides a delay time measuring device and a delay time measuring device capable of measuring forward delay time or reverse delay time without packets having to travel back and forth between measurement sections. The purpose of this invention is to provide a time measurement method and a delay time measurement program.
　本発明は、始点ノードと終点ノードとの間の測定区間で発生するパケット遅延時間を測定する遅延時間測定装置であって、前記測定区間を通過することなく、自装置と前記始点ノードとの間で発生する往復遅延時間を測定する第１遅延時間測定部と、前記測定区間を通過することなく、前記自装置と前記終点ノードとの間で発生する往復遅延時間を測定する第２遅延時間測定部と、自装置から前記測定区間を介して前記自装置まで戻るループの順方向遅延時間および該ループを逆方向に戻るまでの逆方向遅延時間の何れか一方または双方を測定する第３遅延時間測定部と、前記第１遅延時間測定部が測定した第１往復遅延時間および前記第２遅延時間測定部が測定した第２往復遅延時間に基づいて、前記始点ノードと前記終点ノードとの間であって、前記自装置を経由した区間で発生する片道平均遅延時間を演算する片道平均遅延時間演算部と、前記第３遅延時間測定部が前記順方向遅延時間を測定したとき、前記順方向遅延時間から前記片道平均遅延時間を減じて、前記測定区間の順方向遅延時間を演算し、前記第３遅延時間測定部が前記逆方向遅延時間を測定したとき、前記逆方向遅延時間から前記片道平均遅延時間を減じて、前記測定区間の逆方向遅延時間を演算する遅延時間演算部とを有することを特徴とする。 The present invention is a delay time measuring device that measures a packet delay time occurring in a measurement section between a starting point node and a destination node, and the delay time measuring device measures a packet delay time occurring in a measurement section between a starting point node and a destination node. a first delay time measurement section that measures the round trip delay time that occurs between the device itself and the end point node without passing through the measurement section; and a second delay time measurement section that measures the round trip delay time that occurs between the own device and the destination node without passing through the measurement section. and a third delay time for measuring either or both of the forward delay time of a loop returning from the self-device to the self-device via the measurement section and the backward delay time of returning through the loop in the opposite direction. a measurement unit, and a first round trip delay time measured by the first delay time measurement unit and a second round trip delay time measured by the second delay time measurement unit, between the start point node and the end point node. and a one-way average delay time calculation unit that calculates the one-way average delay time occurring in the section via the own device, and when the third delay time measurement unit measures the forward delay time, the forward delay time is calculated by the third delay time measurement unit. The forward delay time of the measurement section is calculated by subtracting the one-way average delay time from the time, and when the third delay time measuring section measures the reverse delay time, the one-way average is calculated from the backward delay time. The method is characterized by comprising a delay time calculation section that calculates a backward delay time of the measurement section by subtracting the delay time.
　本発明によれば、パケットが測定区間を往復することなく順方向遅延時間または逆方向遅延時間を測定することができる。 According to the present invention, forward delay time or reverse delay time can be measured without the packet traveling back and forth in the measurement section.
本発明の第１実施形態である遅延時間測定装置の構成図である。FIG. 1 is a configuration diagram of a delay time measuring device according to a first embodiment of the present invention. 遅延時間測定装置の制御部が実行するフローチャート（１）である。It is a flowchart (1) executed by the control unit of the delay time measuring device. 遅延時間測定装置の制御部が実行するフローチャート（２）である。It is a flowchart (2) executed by the control unit of the delay time measuring device. ネットワークトポロジを把握するための概念図（１）である。FIG. 1 is a conceptual diagram (1) for understanding network topology. 遅延時間測定装置の制御部が実行するフローチャート（３）である。It is a flowchart (3) executed by the control unit of the delay time measuring device. ネットワークトポロジを把握するための概念図（２）である。FIG. 2 is a conceptual diagram (2) for understanding network topology. 始点ノードおよび終点ノードまでの折り返し測定経路を示す図である。FIG. 3 is a diagram showing a return measurement route from a starting point node to an ending point node. 始点ノードおよび終点ノードを通過するループ測定経路を示す図である。FIG. 3 is a diagram showing a loop measurement path passing through a start point node and an end point node. 測定パケットに埋め込まれるラベルの数を低減させるときの概念図である。FIG. 3 is a conceptual diagram when reducing the number of labels embedded in a measurement packet. 測定パケットに埋め込まれるラベルを示す図である。FIG. 3 is a diagram showing labels embedded in measurement packets. ラベル上限超過時に途中経路のラベルを削除するときの概念図である。FIG. 7 is a conceptual diagram when deleting a label of an intermediate route when the label upper limit is exceeded. 折り返し測定経路の遅延時間を測定する概念図である。FIG. 3 is a conceptual diagram of measuring delay time of a return measurement route. ループ測定経路の遅延時間を測定する概念図である。FIG. 3 is a conceptual diagram of measuring delay time of a loop measurement path. 測定区間でパケットロスが発生しているときの概念図である。FIG. 3 is a conceptual diagram when packet loss occurs in a measurement section. 測定区間以外の測定経路でパケットロスが発生しているときの概念図である。FIG. 6 is a conceptual diagram when packet loss occurs on a measurement route other than the measurement section. 本発明の第２実施形態を大規模ネットワークに適用したときの測定経路の一例を示す図である。FIG. 7 is a diagram showing an example of a measurement route when the second embodiment of the present invention is applied to a large-scale network. 測定パケットに埋め込まれるラベルを示す図である。FIG. 3 is a diagram showing labels embedded in measurement packets. 比較例を大規模ネットワークに適用したときの測定経路の一例を示す図である。FIG. 7 is a diagram illustrating an example of a measurement route when a comparative example is applied to a large-scale network. 比較例において、測定パケットに埋め込まれるラベルを示す図である。FIG. 7 is a diagram showing a label embedded in a measurement packet in a comparative example.
　以下、図面を参照して、本発明の実施の形態（以下、「本実施形態」と称する）につき詳細に説明する。なお、各図は、本発明を十分に理解できる程度に、概略的に示してあるに過ぎない。また、各図において、共通する構成要素や同様な構成要素については、同一の符号を付し、それらの重複する説明を省略する。 Hereinafter, an embodiment of the present invention (hereinafter referred to as "the present embodiment") will be described in detail with reference to the drawings. Note that each figure is merely shown schematically to the extent that the present invention can be fully understood. Further, in each figure, common or similar components are denoted by the same reference numerals, and redundant explanation thereof will be omitted.
（第１実施形態）
　図１は、本発明の第１実施形態である遅延時間測定装置の構成図である。
　測定装置１００は、ネットワークＮＷに測定パケットを送出し、送出した測定パケットが戻ってくるまでの遅延時間を測定し、始点ルータ（始点ノード）から終点ルータ（終点ノード）までの測定区間での遅延時間を演算する遅延時間測定装置である。測定装置１００は、制御部１０と、通信部３０と、時計４０と、記憶部５０と、操作表示部６０とのハードウェア資源を備えて構成される。通信部３０は、ネットワークＮＷに設置されている複数のルータ（ルータＡ～ルータＦ（図４））を介して、パケットで通信を行うインタフェースである。時計４０は、測定パケットに押下するタイムスタンプの基準時刻を計時する。記憶部５０は、ＲＯＭ(Read On Memory)やＨＤＤ(Hard Disk Drive)等の不揮発性記憶部やＲＡＭ(Random Access Memory)等の揮発性記憶部から構成される。操作表示部６０は、タッチパネル式のＬＥＤ（Light Emitting Diode）表示器である。 (First embodiment)
FIG. 1 is a configuration diagram of a delay time measuring device according to a first embodiment of the present invention.
The measurement device 100 sends a measurement packet to the network NW, measures the delay time until the sent measurement packet returns, and calculates the delay in the measurement section from the start point router (start point node) to the end point router (end point node). This is a delay time measurement device that calculates time. The measuring device 100 includes hardware resources such as a control section 10, a communication section 30, a clock 40, a storage section 50, and an operation display section 60. The communication unit 30 is an interface that performs packet communication via a plurality of routers (router A to router F (FIG. 4)) installed in the network NW. The clock 40 measures the reference time of the timestamp stamped on the measurement packet. The storage unit 50 includes a non-volatile storage unit such as a ROM (Read On Memory) and an HDD (Hard Disk Drive), and a volatile storage unit such as a RAM (Random Access Memory). The operation display unit 60 is a touch panel type LED (Light Emitting Diode) display.
　制御部１０は、ＣＰＵ（central processing unit）であり、記憶部５０に格納された遅延時間測定プログラムを実行することにより、第１遅延時間測定部１１と、第２遅延時間測定部１２と、第３遅延時間測定部１３と、片道平均遅延時間演算部１４と、遅延時間演算部１５と、パケットロス判定部１６と、測定経路導出部２０と、表示制御部２５との機能を実現する。表示制御部２５は、操作表示部６０を制御する。 The control unit 10 is a CPU (central processing unit), and controls the first delay time measurement unit 11, the second delay time measurement unit 12, and the second delay time measurement unit by executing a delay time measurement program stored in the storage unit 50. The functions of the three delay time measurement section 13, one-way average delay time calculation section 14, delay time calculation section 15, packet loss determination section 16, measurement route derivation section 20, and display control section 25 are realized. The display control unit 25 controls the operation display unit 60.
　第１遅延時間測定部１１は、始点ノードから終点ノードまでの測定区間を通過することなく、自装置と始点ノードとの間で発生する往復遅延時間を測定する。第２遅延時間測定部１２は、始点ノードから終点ノードまでの測定区間を通過することなく、自装置と終点ノードとの間で発生する往復遅延時間を測定する。第３遅延時間測定部１３は、順方向遅延時間測定部１３ａと逆方向遅延時間測定部１３ｂとを備える。順方向遅延時間測定部１３ａは、自装置から測定区間を介して自装置まで戻るループ状の経路（区間測定経路）の順方向遅延時間を測定する。逆方向遅延時間測定部１３ｂは、そのループ状の経路（区間測定経路）を逆方向に戻るまでの逆方向遅延時間を測定する。 The first delay time measurement unit 11 measures the round trip delay time that occurs between the own device and the start node without passing through the measurement section from the start node to the end node. The second delay time measurement unit 12 measures the round trip delay time that occurs between the device itself and the end node without passing through the measurement section from the start node to the end node. The third delay time measuring section 13 includes a forward delay time measuring section 13a and a backward delay time measuring section 13b. The forward delay time measuring unit 13a measures the forward delay time of a loop-shaped route (section measurement route) returning from the own device to the own device via the measurement section. The backward delay time measurement unit 13b measures the backward delay time until the loop path (section measurement path) returns in the opposite direction.
　片道平均遅延時間演算部１４は、第１演算部１４ａと第２演算部１４ｂとを備え、何れか一方を実行する。
　第１演算部１４ａは、第１遅延時間測定部１１が測定した往復遅延時間を２で除した片道平均遅延時間と第２遅延時間測定部１２が測定した往復遅延時間を２で除した片道平均遅延時間とを加算して、片道平均遅延時間を演算する。第２演算部１４ｂは、第１遅延時間測定部１１が測定した往復遅延時間と第２遅延時間測定部１２が測定した往復遅延時間とを加算して、加算された往復遅延時間を２で除して片道平均遅延時間を演算する。 The one-way average delay time calculation section 14 includes a first calculation section 14a and a second calculation section 14b, and executes either one of them.
The first calculation section 14a calculates the one-way average delay time obtained by dividing the round-trip delay time measured by the first delay time measurement section 11 by 2 and the one-way average delay time obtained by dividing the round-trip delay time measured by the second delay time measurement section 12 by 2. The one-way average delay time is calculated by adding the delay time. The second calculation unit 14b adds the round trip delay time measured by the first delay time measurement unit 11 and the round trip delay time measured by the second delay time measurement unit 12, and divides the added round trip delay time by 2. to calculate the one-way average delay time.
　遅延時間演算部１５は、第３遅延時間測定部１３（順方向遅延時間測定部１３ａ）が順方向遅延時間を測定したとき、該順方向遅延時間から片道平均遅延時間を減じて、測定区間の順方向遅延時間を演算する。また、第３遅延時間測定部１３（逆方向遅延時間測定部１３ｂ）が逆方向遅延時間を測定したとき、該逆方向遅延時間から片道平均遅延時間を減じて、測定区間の逆方向遅延時間を演算する。 When the third delay time measurement unit 13 (forward delay time measurement unit 13a) measures the forward delay time, the delay time calculation unit 15 subtracts the one-way average delay time from the forward delay time to calculate the measurement interval. Calculate forward delay time. Further, when the third delay time measuring section 13 (reverse delay time measuring section 13b) measures the backward delay time, the one-way average delay time is subtracted from the backward delay time to determine the backward delay time of the measurement section. calculate.
　パケットロス判定部１６は、第１遅延時間測定部１１または第２遅延時間測定部１２で往復遅延時間や、第３遅延時間測定部１３で測定する順方向遅延時間または逆方向遅延時間を測定するとき、測定パケットが戻って来なかった場合に、パケットロスであると判定する。 The packet loss determination unit 16 measures the round trip delay time using the first delay time measurement unit 11 or the second delay time measurement unit 12, and the forward delay time or reverse delay time measured by the third delay time measurement unit 13. If the measurement packet is not returned, it is determined that there is a packet loss.
　測定経路導出部２０は、測定パケットを送出する前に、測定経路を導出し、測定パケットに測定経路を示すラベルを埋め込むものである。測定経路導出部２０は、情報収集部２１と、トポロジ把握部２２と、経路導出部２３と、ラベル埋込部２４とを備える。 The measurement route derivation unit 20 derives a measurement route and embeds a label indicating the measurement route in the measurement packet before sending the measurement packet. The measurement route derivation unit 20 includes an information collection unit 21, a topology understanding unit 22, a route derivation unit 23, and a label embedding unit 24.
　情報収集部２１は、ネットワークに存在するルータ（ノード）の情報を収集する。トポロジ把握部２２は、ネットワークの測定対象ルータがどのような構成（トポロジ）で接続されているか把握をする。このとき、情報収集部２１は、隣接ルータの情報やリンクコスト（ＩＧＰコスト）を記録する。経路導出部２３は、リンクコストに基づいて、通信経路を導出する。通信経路は、例えば、自装置から始点ルータ（始点ノード）までの最短経路、自装置から終点ルータ（終点ルータ）までの最短経路、該２つの最短経路と測定区間とを連結してループ状にした経路がある。ラベル埋込部２４は、経路導出部２３が導出した経路を示すラベルを測定パケットに埋め込む。 The information collection unit 21 collects information on routers (nodes) existing in the network. The topology grasping unit 22 grasps the configuration (topology) in which the routers to be measured in the network are connected. At this time, the information collection unit 21 records information on adjacent routers and link costs (IGP costs). The route derivation unit 23 derives a communication route based on the link cost. The communication path is, for example, the shortest route from the own device to the start point router (start point node), the shortest path from the own device to the end point router (end point router), and the two shortest paths and the measurement section are connected to form a loop. There is a route. The label embedding unit 24 embeds a label indicating the route derived by the route deriving unit 23 into the measurement packet.
（測定装置１００の動作）
　以下、図２，３，５のフローチャートを参照して、測定経路導出部２０の動作を説明する。
　図２のフローチャートは、情報収集部２１の動作を説明するためのフローチャートである。このフロー（ＳＰ１０）は、電源投入と同時に起動するものであり、所定の処理を一定時間間隔で繰り返すように構成されている（ＳＰ１１～ＳＰ１４）。
　情報収集部２１は、測定対象のルータ（ルータＡ～ルータＦ（図４））や制御装置（不図示）からネットワーク情報を収集する（ＳＰ１２）。ＳＰ１２の後、情報収集部２１は、前回取得時との差分の有無を判定する（ＳＰ１３）。前回取得時との差分がなければ（Ｓ１３で「Ｎｏ」）、ＳＰ１４を介して、ＳＰ１１に戻り、ＳＰ１２，ＳＰ１３の処理を繰り返す。一方、前回取得時との差分があれば（Ｓ１３で「Ｙｅｓ」）、情報収集部２１は、トポロジ把握部２２にトポロジ把握（ＳＰ２０）の処理を行わせる。なお、電源投入時には、前回取得の情報が無いので、Ｓ１３で「Ｙｅｓ」と判定される。 (Operation of measuring device 100)
The operation of the measurement path deriving section 20 will be described below with reference to the flowcharts in FIGS. 2, 3, and 5.
The flowchart in FIG. 2 is a flowchart for explaining the operation of the information collection section 21. This flow (SP10) is started at the same time as the power is turned on, and is configured to repeat predetermined processing at regular time intervals (SP11 to SP14).
The information collecting unit 21 collects network information from the routers to be measured (routers A to F (FIG. 4)) and control devices (not shown) (SP12). After SP12, the information collection unit 21 determines whether there is a difference from the previous acquisition (SP13). If there is no difference from the previous acquisition ("No" in S13), the process returns to SP11 via SP14, and the processes of SP12 and SP13 are repeated. On the other hand, if there is a difference from the previous acquisition ("Yes" in S13), the information collection unit 21 causes the topology understanding unit 22 to perform topology understanding (SP20). Note that when the power is turned on, there is no previously acquired information, so the determination in S13 is "Yes".
　図３は、トポロジ把握部２２の動作を説明するためのフローチャートである。
　このフロー（ＳＰ２０）は、ＳＰ１３（図２）で、前回取得時との差分があったと判定したときに（ＳＰ１３で「Ｙｅｓ」）、起動するものであり、収集した情報に含まれるルータ数分、繰り返すように構成されている（ＳＰ２１～ＳＰ２４）。
　トポロジ把握部２２は、各ルータの情報を記憶部５０（図１）に記録する（ＳＰ２２）。ＳＰ２２の後、隣接ルータの情報、リンクコスト（ＩＧＰ（Interior Gateway Protocol）コスト）を記録する（ＳＰ２３）。ＳＰ２３の処理後、トポロジ把握部２２は、ＳＰ２４を介して、処理をＳＰ２１に戻し、ＳＰ２２，２３の処理をルータ数分、繰り返す。 FIG. 3 is a flowchart for explaining the operation of the topology understanding unit 22.
This flow (SP20) is started when it is determined in SP13 (Figure 2) that there is a difference from the previous acquisition ("Yes" in SP13), and is executed for the number of routers included in the collected information. , is configured to repeat (SP21 to SP24).
The topology understanding unit 22 records information about each router in the storage unit 50 (FIG. 1) (SP22). After SP22, adjacent router information and link cost (IGP (Interior Gateway Protocol) cost) are recorded (SP23). After the processing of SP23, the topology understanding unit 22 returns the processing to SP21 via SP24, and repeats the processing of SP22 and 23 for the number of routers.
　図４は、ネットワークトポロジを把握するための概念図である。
　遅延時間測定システムＳ１は、例えば、測定装置１００に複数（６個）のルータ（ルータＡ～ルータＦ）が接続されたものである。測定装置１００には、ルータＢのみが接続されている。ルータＢには、ルータＡとルータＣとルータＥとが接続されている。ここで、ルータＢとルータＡとの経路を経路ＢＡとし、ルータＢとルータＣとの経路を経路ＢＣとし、ルータＢとルータＥとの経路を経路ＢＥとする。また、ルータＡには、ルータＦが接続されており、ルータＣには、ルータＤが接続されている。ここで、ルータＡとルータＦとの経路を経路ＡＦとし、ルータＣとルータＤとの経路を経路ＣＤとする。ルータＥには、ルータＦとルータＤとが接続されている。ここで、ルータＤとルータＥとの経路を経路ＤＥとし、ルータＥとルータＦとの経路を経路ＥＦとする。また、測定パケットの遅延時間を測定する測定区間は、始点ノードをルータＤとし、終点ノードをルータＦとする。つまり、測定区間は、経路ＤＥと経路ＥＦとを合わせた区間とする。また、始点ノードから終点ノードまでのノード（ルータＤ、ルータＥ及びルータＦ）を測定端点と称する。 FIG. 4 is a conceptual diagram for understanding network topology.
The delay time measurement system S1 is, for example, a measurement device 100 connected to a plurality of (six) routers (router A to router F). Only router B is connected to measuring device 100. Router B is connected to router A, router C, and router E. Here, the route between router B and router A is designated as route BA, the route between router B and router C is designated as route BC, and the route between router B and router E is designated as route BE. Further, router A is connected to router F, and router C is connected to router D. Here, the route between router A and router F is defined as route AF, and the route between router C and router D is defined as route CD. Router F and router D are connected to router E. Here, the route between router D and router E is defined as route DE, and the route between router E and router F is defined as route EF. Further, in the measurement section in which the delay time of the measurement packet is measured, the starting point node is router D, and the ending point node is router F. In other words, the measurement section is a section that includes the route DE and the route EF. Further, the nodes (router D, router E, and router F) from the start point node to the end point node are referred to as measurement end points.
　経路のリンクコスト（ＩＧＰコスト）は、｛１００Ｍｂｐｓ／リンクの帯域幅（ｂｐｓ）｝で定義され、例えば、１００Ｍｂｐｓの帯域幅であれば、リンクコスト＝１である。図４においては、全ての経路ＢＡ，ＢＣ，ＣＤ，ＢＥ，ＡＦ，ＤＥ，ＥＦのリンクコスト（ＩＧＰコスト）を「１」にしている。なお、測定装置１００とルータＢとの間は、リンクコストが極めて小さいとする。 The link cost (IGP cost) of a route is defined as {100 Mbps/link bandwidth (bps)}, and for example, if the bandwidth is 100 Mbps, link cost=1. In FIG. 4, the link cost (IGP cost) of all routes BA, BC, CD, BE, AF, DE, and EF is set to "1". Note that it is assumed that the link cost between the measuring device 100 and the router B is extremely small.
　図５は、遅延時間測定装置の制御部が実行するフローチャートである。
　このフローは、測定パケットをネットワークＮＷ（図１）に放出する前に、図２，３と独立して起動するものであり、ＳＰ３１とＳＰ４０との間を測定端点分、所定の処理を繰り返すように構成されている（ＳＰ３１～ＳＰ４０）。
　ＳＰ３１の後、経路導出部２３（図１）は、測定端点間の経路を導出する（ＳＰ３２）。つまり、経路導出部２３は、測定端点（ルータＤ、ルータＥ、ルータＦ）間の経路ＤＥ，経路ＥＦを導出する。ＳＰ３２の後、経路導出部２３は、測定装置１００から測定始点（ルータＤ）までの経路を導出する（ＳＰ３３）。 FIG. 5 is a flowchart executed by the control unit of the delay time measuring device.
This flow is started independently from FIGS. 2 and 3 before releasing the measurement packet to the network NW (FIG. 1), and repeats the predetermined processing for the measurement end points between SP31 and SP40. (SP31 to SP40).
After SP31, the route derivation unit 23 (FIG. 1) derives a route between the measurement end points (SP32). That is, the route derivation unit 23 derives the route DE and the route EF between the measurement end points (router D, router E, router F). After SP32, the route deriving unit 23 derives a route from the measuring device 100 to the measurement starting point (router D) (SP33).
　図６は、ネットワークトポロジを把握するための概念図である。
　トポロジ把握部２２は、測定区間である経路ＤＥおよび経路ＥＦのリンクコストを「１」から極端に大きな値（例えば、１００）に変更して、測定装置１００から測定始点（ルータＤ）までのリンクコストが最小となる経路を導出する。これにより、経路導出部２３は、（経路ＢＥ＋経路ＤＥ）を選択することなく、（経路ＢＣ＋経路ＣＤ）の経路を導出する。
　図５の説明に戻り、ＳＰ３３の後、経路導出部２３は、測定装置１００から測定終点（ルータＦ）までの経路を導出する（ＳＰ３４）。つまり、経路導出部２３は、（経路ＢＡ＋経路ＡＦ）の経路を導出する。 FIG. 6 is a conceptual diagram for understanding network topology.
The topology grasping unit 22 changes the link costs of the measurement sections route DE and route EF from "1" to an extremely large value (for example, 100), and creates a link from the measurement device 100 to the measurement start point (router D). Derive the route with the minimum cost. Thereby, the route derivation unit 23 derives the route (route BC+route CD) without selecting (route BE+route DE).
Returning to the explanation of FIG. 5, after SP33, the route derivation unit 23 derives a route from the measurement device 100 to the measurement end point (router F) (SP34). That is, the route derivation unit 23 derives the route (route BA+route AF).
　ＳＰ３４の後、経路導出部２３は、ＳＰ３２からＳＰ３４までの結果を元に、区間前折り返し測定経路および区間測定経路を導出する（ＳＰ３５）。測定始点までの最短経路は、ＳＰ３３で導出した（経路ＢＣ＋経路ＣＤ）であり、測定終点までの最短経路は、ＳＰ３４で導出した（経路ＢＡ＋経路ＡＦ）である。したがって、経路導出部２３は、区間前折り返し測定経路として、（経路ＢＣ＋経路ＣＤ）の往復経路（図７の実線α）および（経路ＢＡ＋経路ＡＦ）の往復経路（図７の破線β）を導出する。なお、区間前折り返し測定経路は、測定始点までの最短往復経路と測定終点までの最短往復経路との双方であって、測定端点間の経路（ＳＰ３２）を含まないようにしたものである。 After SP34, the route derivation unit 23 derives a pre-section return measurement route and a section measurement route based on the results from SP32 to SP34 (SP35). The shortest route to the measurement start point is (route BC+route CD) derived at SP33, and the shortest route to the measurement end point is (route BA+route AF) derived at SP34. Therefore, the route deriving unit 23 derives the round trip route (route BC+route CD) (solid line α in FIG. 7) and the round trip route (route BA+route AF) (dashed line β in FIG. 7) as the pre-section return measurement route. do. Note that the pre-section return measurement route includes both the shortest round trip route to the measurement start point and the shortest round trip route to the measurement end point, and does not include the route between the measurement end points (SP32).
　また、区間測定経路は、区間前折り返し測定経路と、測定区間とを合わせたものである。つまり、区間測定経路は、経路ＢＣと経路ＣＤと経路ＤＥと経路ＥＦと経路ＡＦと経路ＢＡとを合わせたループ状の経路である。また、図８の一点鎖線δは、順方向の区間測定経路であり、二点鎖線γは、逆方向の区間測定経路である。 Furthermore, the section measurement route is a combination of the section pre-turnback measurement route and the measurement section. In other words, the section measurement route is a loop-shaped route that is a combination of the route BC, the route CD, the route DE, the route EF, the route AF, and the route BA. Moreover, the dashed-dotted line δ in FIG. 8 is the section measurement route in the forward direction, and the dashed-double line γ is the section measurement route in the backward direction.
　ラベル埋込部２４（図１）は、測定パケットに測定経路を特定するラベルを組み込む。例えば、順方向のループ状の経路（区間測定経路δ）の測定パケットには、「ルータＢ」－「ルータＣ」－「ルータＤ」－「ルータＥ」－「ルータＦ」－「ルータＡ」－「ルータＢ」と計７個のラベルが埋め込まれる（図１０（削減前）参照）。 The label embedding unit 24 (FIG. 1) embeds a label that specifies the measurement route into the measurement packet. For example, a measurement packet for a forward loop route (section measurement route δ) includes "Router B" - "Router C" - "Router D" - "Router E" - "Router F" - "Router A". - "Router B" and a total of seven labels are embedded (see Figure 10 (before reduction)).
　ＳＰ３５の後、経路導出部２３は、ラベルを省略しても経路が一意になる区間があるか否か判定する（ＳＰ３６）。ラベルを省略しても経路が一意になる区間があれば（Ｓ３６で「Ｙｅｓ」）、経路導出部２３は、当該区間にある装置（ルータ）のラベルを測定経路から削除し（ＳＰ３７）、処理をＳ３８に進める。 After SP35, the route derivation unit 23 determines whether there is a section where the route is unique even if the label is omitted (SP36). If there is a section where the route will be unique even if the label is omitted ("Yes" in S36), the route derivation unit 23 deletes the label of the device (router) in the section from the measurement route (SP37), and performs processing. Proceed to S38.
　図９は、測定パケットに埋め込まれるラベルの数を低減させるときの概念図である。
　ルータＢからルータＤまでの最短経路は、（経路ＢＣ＋経路ＣＤ）と（経路ＢＥ＋経路ＤＥ）との複数（２つ）あり、ルータＢからルータＦまでの最短経路は、（経路ＢＡ＋経路ＡＦ）と（経路ＢＥ＋経路ＥＦ）との複数（２つ）ある。そのため、ラベルを省略すると、経路が一意にならない。 FIG. 9 is a conceptual diagram when reducing the number of labels embedded in a measurement packet.
There are multiple (two) shortest routes from router B to router D: (route BC + route CD) and (route BE + route DE), and the shortest route from router B to router F is (route BA + route AF). There is a plurality (two) of (route BE+route EF). Therefore, if the label is omitted, the route will not be unique.
　一方、ルータＤからルータＦまでの経路（経路ＤＥ＋経路ＥＦ）は、最短経路として、必ずルータＥを通るため、ラベル「ルータＥ」を省略しても経路が一意になる。 On the other hand, since the route from router D to router F (route DE+route EF) always passes through router E as the shortest route, the route will be unique even if the label "router E" is omitted.
　図１０は、測定パケットに埋め込まれるラベルを示す図である。
　例えば、順方向の区間測定経路δでは、削除前には、「ルータＢ」－「ルータＣ」－「ルータＤ」－「ルータＥ」－「ルータＦ」－「ルータＡ」－「ルータＢ」の順で計７個のラベルが埋め込まれていたが、「ルータＥ」が削除されると、「ルータＢ」－「ルータＣ」－「ルータＤ」－「ルータＦ」－「ルータＡ」－「ルータＢ」の順で６個のラベルが埋め込まれる。 FIG. 10 is a diagram showing labels embedded in measurement packets.
For example, in the forward section measurement route δ, before deletion, "Router B" - "Router C" - "Router D" - "Router E" - "Router F" - "Router A" - "Router B" A total of seven labels were embedded in this order, but when "Router E" is deleted, "Router B" - "Router C" - "Router D" - "Router F" - "Router A" - Six labels are embedded in the order of "Router B".
　図５のフローチャートの説明に戻り、一方、ラベルを省略しても経路が一意になる区間が無ければ（Ｓ３６（図５）で「Ｎｏ」）、経路導出部２３は、処理をＳ３８に進める。 Returning to the explanation of the flowchart in FIG. 5, on the other hand, if there is no section in which the route becomes unique even if the label is omitted ("No" in S36 (FIG. 5)), the route derivation unit 23 advances the process to S38.
　ＳＰ３８では、測定経路のラベル数が装置上限を超過しているか否か判定する。ラベル上限数を超過した測定パケットをルータに送信したときには、故障や不具合を起こす可能性がある。ラベル数が装置上限を超過していれば（ＳＰ３８で「Ｙｅｓ」）、ラベル上限以下になるまでラベルを削減し（ＳＰ３９）、ＳＰ４０とＳＰ３１との間の処理を繰り返す。一方、ラベル数が装置上限を超過していなければ（ＳＰ３８で「Ｎｏ」）、ＳＰ４０とＳＰ３１との間の処理を繰り返す。 At SP38, it is determined whether the number of labels on the measurement path exceeds the upper limit of the device. If a measurement packet exceeding the upper limit number of labels is sent to the router, there is a possibility that a failure or malfunction will occur. If the number of labels exceeds the device upper limit ("Yes" in SP38), the number of labels is reduced until it becomes less than the label upper limit (SP39), and the processing between SP40 and SP31 is repeated. On the other hand, if the number of labels does not exceed the device upper limit ("No" in SP38), the processing between SP40 and SP31 is repeated.
　図１１は、ラベル上限超過時に途中経路のラベルを削除するときの概念図である。
　順方向の区間測定経路δでは、７個のラベルが埋め込まれるべきであるが、ルータのラベル上限数が５個であるとき、ルータＥのラベルを省略しても足りない。このとき、ラベル埋込部２４（図１）は、例えば、ルータＡおよびルータＣのラベルの埋め込みを省略するとする。そのときには、測定パケットは、ルータＢ→ルータＥ→ルータＤ→ルータＥ→ルータＦ→ルータＥ→ルータＢの経路を通過してしまう可能性がある。つまり、ラベル削減によって、経路が一意にならなくなり、経路重複が起こってしまう。結果的に、遅延時間の測定精度が低下するものの、大規模ネットワークでも測定可能になる。 FIG. 11 is a conceptual diagram when a label of an intermediate route is deleted when the label upper limit is exceeded.
Seven labels should be embedded in the forward section measurement path δ, but when the upper limit of the number of labels for a router is five, omitting the label for router E is not enough. At this time, it is assumed that the label embedding unit 24 (FIG. 1) omits, for example, embedding the labels of router A and router C. In that case, there is a possibility that the measurement packet passes through the route of router B→router E→router D→router E→router F→router E→router B. In other words, due to label reduction, routes are no longer unique and route duplication occurs. As a result, although the accuracy of measuring delay time decreases, it becomes possible to measure it even in large-scale networks.
　図１２は、折り返し測定経路の遅延時間を測定する概念図である。
　第１遅延時間測定部１１（図１）は、始点ノード（ルータＤ）までの区間前折り返し測定経路αのラベルを埋め込んだ測定パケットを放出し、戻ってくるまでの時間（始点往復遅延時間Ｔα）を測定する。第２遅延時間測定部１２（図１）は、終点ノード（ルータＦ）までの区間前折り返し測定経路βのラベルを埋め込んだ測定パケットを放出し、戻ってくるまでの時間（終点往復遅延時間Ｔβ）を測定する。さらに、片道平均遅延時間演算部１４（図１）は、片道平均遅延時間（Ｔα＋Ｔβ）／２を演算する。 FIG. 12 is a conceptual diagram of measuring the delay time of the return measurement path.
The first delay time measuring unit 11 (FIG. 1) emits a measurement packet in which a label of the section pre-turnback measurement route α to the start point node (router D) is embedded, and the time it takes to return (start point round trip delay time Tα ) to measure. The second delay time measurement unit 12 (FIG. 1) emits a measurement packet embedded with a label of the pre-section return measurement route β to the end point node (router F), and the time it takes to return (end point round trip delay time Tβ ) to measure. Furthermore, the one-way average delay time calculating section 14 (FIG. 1) calculates the one-way average delay time (Tα+Tβ)/2.
　図１３は、ループ測定経路の遅延時間を測定する概念図である。
　第３遅延時間測定部１３の順方向遅延時間測定部１３ａ（図１）は、順方向の区間測定経路δのラベルを埋め込んだ測定パケット（測定区間を経由する測定パケット）を放出し、戻ってくるまでの時間（順方向遅延時間Ｔδ）を測定する。逆方向遅延時間測定部１３ｂ（図１）は、逆方向の区間測定経路γのラベルを埋め込んだ測定パケット（測定区間を経由する測定パケット）を放出し、戻ってくるまでの時間（逆方向遅延時間Ｔγ）を測定する。 FIG. 13 is a conceptual diagram of measuring the delay time of a loop measurement path.
The forward delay time measuring unit 13a (FIG. 1) of the third delay time measuring unit 13 emits a measurement packet (a measurement packet that passes through the measurement interval) in which the label of the forward section measurement route δ is embedded, and returns the measurement packet. The time it takes for this to occur (forward delay time Tδ) is measured. The backward delay time measuring unit 13b (FIG. 1) emits a measurement packet (a measurement packet that passes through the measurement section) in which a label of the backward section measurement path γ is embedded, and the time it takes for it to return (reverse direction delay). The time Tγ) is measured.
　遅延時間演算部１５（図１）は、順方向遅延時間測定部１３ａが順方向遅延時間Ｔδを測定したとき、その順方向遅延時間Ｔδから片道平均遅延時間（Ｔα＋Ｔβ）／２を減じて、測定区間の順方向遅延時間｛Ｔδ－（Ｔα＋Ｔβ）／２｝を演算する。また、逆方向遅延時間測定部１３ｂが逆方向遅延時間Ｔγを測定したとき、その逆方向遅延時間Ｔγから片道平均遅延時間（Ｔα＋Ｔβ）／２を減じて、測定区間の逆方向遅延時間｛Ｔγ－（Ｔα＋Ｔβ）／２｝を演算する。 When the forward delay time measurement unit 13a measures the forward delay time Tδ, the delay time calculation unit 15 (FIG. 1) subtracts the one-way average delay time (Tα+Tβ)/2 from the forward delay time Tδ to calculate the measurement result. The forward delay time of the section {Tδ−(Tα+Tβ)/2} is calculated. Furthermore, when the backward delay time measurement unit 13b measures the backward delay time Tγ, the one-way average delay time (Tα+Tβ)/2 is subtracted from the backward delay time Tγ to calculate the backward delay time {Tγ− (Tα+Tβ)/2} is calculated.
　例えば、始点往復遅延時間Ｔα＝１００μＳｅｃであり、終点往復遅延時間Ｔβ＝５０μＳｅｃであるとき、片道平均遅延時間（Ｔα＋Ｔβ）／２＝７５μＳｅｃとなる。測定された順方向遅延時間Ｔδ＝１２５μＳｅｃであるとき、測定区間の順方向遅延時間｛Ｔδ－（Ｔα＋Ｔβ）／２｝＝５０μＳｅｃとなる。また、測定された逆方向遅延時間Ｔγ＝１４５μＳｅｃであるとき、測定区間の逆方向遅延時間｛Ｔγ－（Ｔα＋Ｔβ）／２｝＝７０μＳｅｃとなる。 For example, when the start point round trip delay time Tα=100 μSec and the end point round trip delay time Tβ=50 μSec, the one-way average delay time (Tα+Tβ)/2=75 μSec. When the measured forward delay time Tδ=125 μSec, the forward delay time of the measurement section becomes {Tδ−(Tα+Tβ)/2}=50 μSec. Further, when the measured backward delay time Tγ=145 μSec, the backward delay time of the measurement section becomes {Tγ−(Tα+Tβ)/2}=70 μSec.
　図１４は、測定区間でパケットロスが発生しているときの概念図である。
　パケットロス判定部１６（図１）は、測定装置１００から測定始点（ルータＤ）までの区間前折り返し測定経路αの始点往復遅延時間Ｔαや、測定終点（ルータＦ）までの区間前折り返し測定経路βの終点往復遅延時間Ｔβの測定を実行することができ、測定区間を経由する測定パケットが測定装置１００に戻ってこなかったとき、測定区間（経路ＤＥ＋経路ＥＦ）でパケットロスが発生している、と判定する。 FIG. 14 is a conceptual diagram when packet loss occurs in the measurement interval.
The packet loss determination unit 16 (FIG. 1) determines the starting point round trip delay time Tα of the section pre-turnback measurement route α from the measurement device 100 to the measurement start point (router D), and the section pre-turnback measurement route from the measurement device 100 to the measurement end point (router F). When the end point round trip delay time Tβ of β can be measured and the measurement packet passing through the measurement section does not return to the measurement device 100, a packet loss has occurred in the measurement section (route DE + route EF). , it is determined.
　図１５は、測定区間以外の測定経路でパケットロスが発生しているときの概念図である。
　パケットロス判定部１６（図１）は、測定始点（ルータＤ）までの区間前折り返し測定経路αおよび測定終点（ルータＦ）までの区間前折り返し測定経路βの遅延時間Ｔα，Ｔβの測定が不可だったときには、測定装置１００から測定区間（ルータＤまたはルータＦ）までの経路で異常があったと判定する。 FIG. 15 is a conceptual diagram when packet loss occurs on a measurement route other than the measurement section.
The packet loss determination unit 16 (FIG. 1) is unable to measure the delay times Tα and Tβ of the pre-section return measurement route α to the measurement start point (router D) and the pre-section return measurement route β to the measurement end point (router F). If so, it is determined that there is an abnormality in the path from the measurement device 100 to the measurement section (router D or router F).
　以上説明したように、本実施形態の測定装置１００は、ネットワークＮＷ（図１）内の測定区間（始点ノードから終点ノード）の遅延時間を測定・演算することができるように構成されている。測定装置１００は、始点往復遅延時間Ｔαと、終点往復遅延時間Ｔβと、測定区間の順方向遅延時間Ｔδおよび逆方向遅延時間Ｔγの何れか一方または双方とを測定し、｛Ｔδ－（Ｔα＋Ｔβ）／２｝および｛Ｔγ－（Ｔα＋Ｔβ）／２｝の何れか一方または双方を演算することにより、測定区間の遅延時間を求めることができる。 As explained above, the measuring device 100 of this embodiment is configured to be able to measure and calculate the delay time of the measurement section (from the starting point node to the ending point node) in the network NW (FIG. 1). The measuring device 100 measures the starting point round trip delay time Tα, the ending point round trip delay time Tβ, and either or both of the forward direction delay time Tδ and the backward direction delay time Tγ of the measurement section, and calculates {Tδ−(Tα+Tβ) /2} and {Tγ−(Tα+Tβ)/2} or both, the delay time of the measurement interval can be determined.
　測定装置１００は、測定始点（ルータＤ）までの区間前折り返し測定経路αと、測定終点（ルータＦ）までの区間前折り返し測定経路βと、順方向の区間測定経路δと、逆方向の区間測定経路γとを示すラベルを測定パケットに埋め込んでいる。また、測定装置１００は、測定経路のルータを示すラベルの一部を省略しても経路を一意に特定できるときには、測定パケットに埋め込むラベルを省略する。これにより、ルータのラベル上限数を超えてしまうときにも、ラベルの省略により、ラベル上限数の超過を回避することができる。また、測定装置１００は、始点往復遅延時間Ｔαや終点往復遅延時間Ｔβの測定が不可だったときに、測定装置１００から測定区間（ルータＤまたはルータＦ）までの経路で異常があったと判定する。 The measuring device 100 has a pre-section return measurement route α to the measurement start point (router D), a pre-section return measurement route β to the measurement end point (router F), a section measurement route δ in the forward direction, and a section in the reverse direction. A label indicating the measurement route γ is embedded in the measurement packet. Furthermore, the measuring device 100 omits the label embedded in the measurement packet when the route can be uniquely identified even if a part of the label indicating the router of the measurement route is omitted. Thereby, even when the upper limit number of labels of the router is exceeded, by omitting labels, it is possible to avoid exceeding the upper limit number of labels. In addition, the measuring device 100 determines that there is an abnormality in the path from the measuring device 100 to the measurement section (router D or router F) when it is not possible to measure the starting point round trip delay time Tα or the ending point round trip delay time Tβ. .
（第２実施形態）
　図１６は、本発明の第２実施形態であり、測定装置を大規模ネットワークに適用したときの測定経路の一例を示す図である。
　遅延時間測定システムＳ２は、測定装置１００と、複数のルータＡ～Ｊを備えて構成される。測定装置１００とルータＡとが接続されており、ルータＡとルータＣ，Ｄ，Ｅ，Ｆとが接続されており、ルータＣとルータＢ，Ｈ等とが接続されており、ルータＤとルータＢ，Ｈ等と接続されており、ルータＥとルータＢ，Ｊ等とが接続されており、ルータＦとルータＢ，Ｊ等とが接続されている。 (Second embodiment)
FIG. 16 is a second embodiment of the present invention, and is a diagram showing an example of a measurement route when the measurement device is applied to a large-scale network.
The delay time measurement system S2 includes a measurement device 100 and a plurality of routers A to J. The measuring device 100 and router A are connected, the router A and routers C, D, E, and F are connected, the router C is connected to routers B, H, etc., and the router D and router Router B, H, etc. are connected, router E is connected to routers B, J, etc., and router F is connected to routers B, J, etc.
　測定区間は、ルータＪ→ルータＥ→ルータＡ→ルータＤ→ルータＨとする。つまり、測定区間の始点ノードは、ルータＪであり終点ノードはルータＨである。
　このとき、区間前折り返し測定経路αは、ルータＡ→ルータＦ→ルータＪ→ルータＦ→ルータＡである。また、区間前折り返し測定経路βは、ルータＡ→ルータＣ→ルータＨ→ルータＣ→ルータＡである。また、順方向のループδは、ルータＡ→ルータＦ→ルータＪ→ルータＥ→ルータＡ→ルータＤ→ルータＨ→ルータＣ→ルータＡである。逆方向のループγは、ルータＡ→ルータＣ→ルータＨ→ルータＤ→ルータＡ→ルータＥ→ルータＪ→ルータＦ→ルータＡである。
　なお、区間前折り返し測定経路α，βは、測定区間を特定するノード（ルータＡ）を含んでいる。 The measurement section is Router J → Router E → Router A → Router D → Router H. That is, the starting point node of the measurement section is router J, and the ending point node is router H.
At this time, the pre-section return measurement route α is Router A → Router F → Router J → Router F → Router A. Further, the pre-section return measurement route β is Router A→Router C→Router H→Router C→Router A. Further, the forward loop δ is Router A→Router F→Router J→Router E→Router A→Router D→Router H→Router C→Router A. The loop γ in the reverse direction is Router A → Router C → Router H → Router D → Router A → Router E → Router J → Router F → Router A.
Note that the pre-section return measurement routes α and β include a node (router A) that specifies the measurement section.
　図１７は、測定パケットに埋め込まれるラベルを示す図である。
　順方向のループδでは、「ルータＡ」－「ルータＦ」－「ルータＪ」－「ルータＥ」－「ルータＡ」－「ルータＤ」－「ルータＨ」－「ルータＣ」－「ルータＡ」の順で、計９個のラベルが埋め込まれる。 FIG. 17 is a diagram showing labels embedded in measurement packets.
In the forward loop δ, "Router A" - "Router F" - "Router J" - "Router E" - "Router A" - "Router D" - "Router H" - "Router C" - "Router A" A total of nine labels are embedded in this order.
（比較例）
　図１８は、比較例を大規模ネットワークに適用したときの測定経路の一例を示す図である。
　遅延時間測定システムＳ２の構成は、前記実施形態の遅延時間測定システムＳ２（図１６）と同一である。しかしながら、測定装置１００が測定パケットを通過させる経路と遅延時間演算方法とが異なる。
　具体的には、測定装置１００は、自装置から終点ノード（ルータＨ）までの測定経路εの往復遅延時間ＴＥと、自装置から始点ノード（ルータＪ）までの測定経路αの往復遅延時間ＴＳとを測定し、測定区間の片道平均遅延時間ＴａをＴａ＝（ＴＥ－ＴＳ）／２を演算して求めている。そのため、測定経路αに測定区間（ルータＪ－ルータＥ－ルータＡ）が含まれてしまっている。 (Comparative example)
FIG. 18 is a diagram illustrating an example of a measurement route when the comparative example is applied to a large-scale network.
The configuration of the delay time measurement system S2 is the same as the delay time measurement system S2 (FIG. 16) of the previous embodiment. However, the route through which the measurement device 100 passes the measurement packet and the delay time calculation method are different.
Specifically, the measurement device 100 calculates the round trip delay time TE of the measurement path ε from the device to the end node (router H) and the round trip delay time TS of the measurement path α from the device to the start node (router J). The one-way average delay time Ta of the measurement section is calculated by calculating Ta=(TE-TS)/2. Therefore, the measurement route α includes the measurement section (router J-router E-router A).
　しかしながら、第２実施形態（図１６）では、測定経路αに測定区間（ルータＪ－ルータＥ－ルータＡ－ルータＤ－ルータＨ）が含まれていない。 However, in the second embodiment (FIG. 16), the measurement path α does not include the measurement section (router J-router E-router A-router D-router H).
　図１９は、比較例において、測定パケットに埋め込まれるラベルを示す図である。
　終点ノードまでの往復遅延時間測定経路εでは、「ルータＡ」－「ルータＥ」－「ルータＪ」－「ルータＥ」－「ルータＡ」－「ルータＤ」－「ルータＨ」－［ルータＤ］－「ルータＡ」－「ルータＥ」－「ルータＪ」－「ルータＥ」－「ルータＡ」の順で、計１３個のラベルが埋め込まれる。 FIG. 19 is a diagram showing labels embedded in measurement packets in a comparative example.
In the round trip delay time measurement route ε to the end node, "Router A" - "Router E" - "Router J" - "Router E" - "Router A" - "Router D" - "Router H" - [Router D ] - "Router A" - "Router E" - "Router J" - "Router E" - "Router A", a total of 13 labels are embedded in this order.
　本比較例では、ラベルの数が１３個であるのに対して、前記第２実施形態では、ラベルの数が９個に低減している。つまり、本比較例では、測定パケットが同じ経路を往復するように測定経路を指定している。そのため、測定区間の中継地点が１つ増えると測定経路は往路、復路の２つ分、ラベルが増加する。しかしながら、前記第１，２実施形態では、測定区間の中継地点が１つ増えたとき、区間測定経路δ，γを示すラベルも１つ増えるだけである。 In this comparative example, the number of labels is 13, whereas in the second embodiment, the number of labels is reduced to 9. In other words, in this comparative example, the measurement route is specified so that the measurement packets reciprocate along the same route. Therefore, when the number of relay points in the measurement section increases by one, the number of labels increases by two for the outbound and return routes of the measurement route. However, in the first and second embodiments, when the number of relay points in the measurement section increases by one, the number of labels indicating the section measurement routes δ and γ also increases by one.
　また、本比較例では、例えば、測定区間、例えば、ルータＥとルータＪとの間で、パケットロスなどの品質劣化が発生したときには、始点ノードまでの往復遅延時間測定経路αも、終点ノードまでの往復遅延時間測定経路εも測定パケットが戻ってこない。
　一方、前記第２実施形態の遅延時間測定方法によれば、ルータＥとルータＪとの間で、パケットロスが発生したとしても、ループδ，γの測定パケットは戻ってこないが、区間前折り返し測定経路α，βの測定パケットが戻ってくるので、ルータＥとルータＪとを含む測定区間で、パケットロスが発生したと判定することができる。 In addition, in this comparative example, when quality deterioration such as packet loss occurs in the measurement section, for example, between router E and router J, the round trip delay time measurement route α to the starting point node is also changed to the ending point node. The measurement packet does not return on the round trip delay time measurement path ε.
On the other hand, according to the delay time measurement method of the second embodiment, even if a packet loss occurs between router E and router J, the measurement packets of loops δ and γ will not be returned, but Since the measurement packets from the measurement routes α and β are returned, it can be determined that a packet loss has occurred in the measurement section including routers E and J.
＜効果＞
　以下、本発明の遅延時間測定装置の効果について説明する。
　本発明の実施形態に係る遅延時間測定装置１００は、始点ノードと終点ノードとの間の測定区間（区間ＤＥ＋区間ＥＦ）で発生するパケット遅延時間を測定する遅延時間測定装置１００であって、前記測定区間を通過することなく、自装置と前記始点ノード（ルータＤ）との間で発生する往復遅延時間（Ｔα）を測定する第１遅延時間測定部（１１）と、前記測定区間を通過することなく、前記自装置と前記終点ノード（ルータＦ）との間で発生する往復遅延時間（Ｔβ）を測定する第２遅延時間測定部（１２）と、自装置から前記測定区間を介して前記自装置まで戻るループ（δ）の順方向遅延時間（Ｔδ）および該ループを逆方向に戻るまでの逆方向遅延時間（Ｔγ）の何れか一方または双方を測定する第３遅延時間測定部（１３）と、前記第１遅延時間測定部（１１）が測定した第１往復遅延時間（Ｔα）および前記第２遅延時間測定部が測定した第２往復遅延時間（Ｔβ）に基づいて、前記始点ノード（ルータＤ）と前記終点ノード（ルータＦ）との間であって、前記自装置を経由した区間で発生する片道平均遅延時間｛（Ｔα＋Ｔβ）／２｝を演算する片道平均遅延時間演算部（１４）と、前記第３遅延時間測定部（１３）が前記順方向遅延時間（Ｔδ）を測定したとき、前記順方向遅延時間（Ｔδ）から前記片道平均遅延時間｛（Ｔα＋Ｔβ）／２｝を減じて、前記測定区間の順方向遅延時間を演算し、前記第３遅延時間測定部（１３）が前記逆方向遅延時間（Ｔγ）を測定したとき、前記逆方向遅延時間（Ｔγ）から前記片道平均遅延時間｛（Ｔα＋Ｔβ）／２｝を減じて、前記測定区間の逆方向遅延時間を演算する遅延時間演算部（１５）とを有することを特徴とする。 <Effect>
Hereinafter, the effects of the delay time measuring device of the present invention will be explained.
A delay time measuring device 100 according to an embodiment of the present invention is a delay time measuring device 100 that measures a packet delay time occurring in a measurement section (section DE+section EF) between a start point node and a destination node, and includes the a first delay time measurement unit (11) that measures a round trip delay time (Tα) occurring between the own device and the start point node (router D) without passing through the measurement section; a second delay time measurement unit (12) that measures the round trip delay time (Tβ) occurring between the own device and the end point node (router F); a third delay time measurement unit (13 ), the first round trip delay time (Tα) measured by the first delay time measuring unit (11), and the second round trip delay time (Tβ) measured by the second delay time measuring unit A one-way average delay time calculation unit ((Tα+Tβ)/2} that calculates the one-way average delay time {(Tα+Tβ)/2} occurring in the section between (Router D) and the end point node (Router F) via the own device; 14) When the third delay time measurement unit (13) measures the forward delay time (Tδ), the one-way average delay time {(Tα+Tβ)/2} is calculated from the forward delay time (Tδ). When the third delay time measuring unit (13) measures the backward delay time (Tγ), the one-way delay time is calculated by subtracting the forward delay time of the measurement section. It is characterized by comprising a delay time calculation unit (15) that calculates the backward delay time of the measurement section by subtracting the average delay time {(Tα+Tβ)/2}.
　これによれば、パケットが測定区間を往復することなく、測定区間における順方向遅延時間及び逆方向遅延時間の何れか一方または双方を測定することができる。そのため、測定区間を中継する中継ノードが１つ増えたとしても、第３遅延時間測定部が遅延時間を測定する測定経路を中継する中継ノードも１つ増えるだけである。 According to this, one or both of the forward delay time and the reverse delay time in the measurement section can be measured without the packet traveling back and forth in the measurement section. Therefore, even if the number of relay nodes that relay the measurement section increases by one, the number of relay nodes that relay the measurement path on which the third delay time measuring section measures the delay time also increases by one.
　また、第１遅延時間測定部（１１）および第２遅延時間測定部（１２）は、前記第１往復遅延時間（Ｔα）または前記第２往復遅延時間（Ｔβ）を測定するときに、前記測定区間を特定するノード（例えば、自装置に接続するルータＡ）を通過させても構わない。言い換えれば、自装置と始点ノードまでの経路および自装置と終点ノードまでの経路は測定区間と異なる必要があるが、ノードは共通していても構わない。これにより、自装置に接続されるノードを測定区間に含めることができる。 Further, when measuring the first round trip delay time (Tα) or the second round trip delay time (Tβ), the first delay time measuring unit (11) and the second delay time measuring unit (12) It is also possible to pass through a node that specifies the section (for example, router A connected to the own device). In other words, the route from the own device to the start point node and the route from the own device to the end point node need to be different from the measurement section, but the nodes may be common. Thereby, nodes connected to the own device can be included in the measurement section.
　また、最短経路が一意となるノードのラベルを省略した複数のラベルを前記パケットに埋め込むラベル埋込部（２４）をさらに備えることを特徴とする。これにより、最短経路が一意となるノードのラベルが省略されることから、測定経路を示すラベルの数が低減する。 The present invention is also characterized by further comprising a label embedding unit (24) that embeds a plurality of labels into the packet, omitting the label of the node for which the shortest path is unique. As a result, the label of the node for which the shortest route is unique is omitted, so the number of labels indicating the measurement route is reduced.
　前記第１遅延時間測定部（１１）または前記第２遅延時間測定部（１２）で前記往復遅延時間（Ｔα，Ｔβ）を測定できなかったときにパケットロスと判定するパケットロス判定部（１６）をさらに備えることを特徴とする。これによれば、自装置と始点ノードとの間または自装置と終点ノードとの間で生じたパケットロスを判定することができる。つまり、順方向遅延時間（Ｔδ）または逆方向遅延時間（Ｔγ）を測定できれば、測定区間以外で、パケットロスが発生していることになる。 a packet loss determination unit (16) that determines a packet loss when the round trip delay time (Tα, Tβ) cannot be measured by the first delay time measurement unit (11) or the second delay time measurement unit (12); It is characterized by further comprising: According to this, it is possible to determine a packet loss that has occurred between the own device and the start point node or between the own device and the end point node. In other words, if the forward delay time (Tδ) or the reverse delay time (Tγ) can be measured, it means that packet loss has occurred outside the measurement period.
　また、前記片道平均遅延時間演算部（１４）は、前記第１遅延時間測定部（１１）が測定した往復遅延時間（Ｔα）を２で除した片道平均遅延時間（Ｔα／２）と前記第２遅延時間測定部（１２）が測定した往復遅延時間（Ｔβ）を２で除した片道平均遅延時間（Ｔβ／２）とを加算する第１演算（第１演算部１４ａの演算）と、前記第１遅延時間測定部（１２）が測定した往復遅延時間（Ｔα）と前記第２遅延時間測定部（１２）が測定した往復遅延時間（Ｔβ）とを加算して、加算された往復遅延時間を２で除して片道平均遅延時間｛（Ｔα＋Ｔβ）／２｝を演算する第２演算との何れか一方の演算を実行することを特徴とする。これにより、往復遅延時間（Ｔα，Ｔβ）から片道平均遅延時間｛（Ｔα＋Ｔβ）／２｝を演算することができる。 Further, the one-way average delay time calculation unit (14) calculates the one-way average delay time (Tα/2) obtained by dividing the round trip delay time (Tα) measured by the first delay time measurement unit (11) by 2, and the one-way average delay time (Tα/2). 2. A first calculation (calculation of the first calculation unit 14a) that adds the round trip delay time (Tβ) measured by the delay time measurement unit (12) to the one-way average delay time (Tβ/2) divided by 2; The round trip delay time (Tα) measured by the first delay time measurement unit (12) and the round trip delay time (Tβ) measured by the second delay time measurement unit (12) are added to obtain the added round trip delay time. It is characterized in that either one of the calculations is executed, and the second calculation is to divide by 2 and calculate the one-way average delay time {(Tα+Tβ)/2}. Thereby, the one-way average delay time {(Tα+Tβ)/2} can be calculated from the round trip delay time (Tα, Tβ).
　１０　制御部
　１１　第１遅延時間測定部
　１２　第２遅延時間測定部
　１３　第３遅延時間測定部
　１３ａ　順方向遅延時間測定部
　１３ｂ　逆方向遅延時間測定部
　１４　片道平均遅延時間演算部
　１４ａ　第１演算部
　１４ｂ　第２演算部
　１５　遅延時間演算部
　１６　パケットロス判定部
　２０　測定経路導出部
　２３　経路導出部
　２４　ラベル埋込部
１００　測定装置（遅延時間測定装置）
  10 Control section 11 First delay time measurement section 12 Second delay time measurement section 13 Third delay time measurement section 13a Forward delay time measurement section 13b Reverse delay time measurement section 14 One-way average delay time calculation section 14a First calculation section 14b Second calculation unit 15 Delay time calculation unit 16 Packet loss determination unit 20 Measurement route derivation unit 23 Route derivation unit 24 Label embedding unit 100 Measuring device (delay time measuring device)

Claims (7)

  1. 　始点ノードと終点ノードとの間の測定区間で発生するパケット遅延時間を測定する遅延時間測定装置であって、
    　前記測定区間を通過することなく、自装置と前記始点ノードとの間で発生する往復遅延時間を測定する第１遅延時間測定部と、
    　前記測定区間を通過することなく、前記自装置と前記終点ノードとの間で発生する往復遅延時間を測定する第２遅延時間測定部と、
    　自装置から前記測定区間を介して前記自装置まで戻るループの順方向遅延時間および該ループを逆方向に戻るまでの逆方向遅延時間の何れか一方または双方を測定する第３遅延時間測定部と、
    　前記第１遅延時間測定部が測定した第１往復遅延時間および前記第２遅延時間測定部が測定した第２往復遅延時間に基づいて、前記始点ノードと前記終点ノードとの間であって、前記自装置を経由した区間で発生する片道平均遅延時間を演算する片道平均遅延時間演算部と、
    　前記第３遅延時間測定部が前記順方向遅延時間を測定したとき、前記順方向遅延時間から前記片道平均遅延時間を減じて、前記測定区間の順方向遅延時間を演算し、前記第３遅延時間測定部が前記逆方向遅延時間を測定したとき、前記逆方向遅延時間から前記片道平均遅延時間を減じて、前記測定区間の逆方向遅延時間を演算する遅延時間演算部と
    を有することを特徴とする遅延時間測定装置。     A delay time measurement device that measures packet delay time occurring in a measurement section between a start point node and a destination node,
    a first delay time measurement unit that measures a round trip delay time that occurs between the own device and the start point node without passing through the measurement section;
    a second delay time measurement unit that measures a round trip delay time that occurs between the own device and the end point node without passing through the measurement section;
    a third delay time measurement unit that measures either or both of a forward delay time of a loop returning from the own device to the own device via the measurement section and a backward delay time of returning through the loop in the reverse direction; ,
    between the start point node and the end point node based on the first round trip delay time measured by the first delay time measuring section and the second round trip delay time measured by the second delay time measuring section, a one-way average delay time calculation unit that calculates the one-way average delay time occurring in the section via the own device;
    When the third delay time measuring unit measures the forward delay time, the one-way average delay time is subtracted from the forward delay time to calculate the forward delay time of the measurement section, and the third delay time is calculated by subtracting the one-way average delay time from the forward delay time. and a delay time calculating section that calculates the backward delay time of the measurement section by subtracting the one-way average delay time from the backward delay time when the measuring section measures the backward delay time. Delay time measuring device.
  2. 　請求項１に記載の遅延時間測定装置であって、
    　第１遅延時間測定部および第２遅延時間測定部は、前記往復遅延時間を測定するときに、前記測定区間を特定するノードを通過させても構わない
    ことを特徴とする遅延時間測定装置。     The delay time measuring device according to claim 1,
    A delay time measuring device, wherein the first delay time measuring section and the second delay time measuring section may pass through a node that specifies the measurement section when measuring the round trip delay time.
  3. 　請求項１に記載の遅延時間測定装置であって、
    　最短経路が一意となるノードのラベルを省略した複数のラベルをパケットに埋め込むラベル埋込部をさらに備える
    ことを特徴とする遅延時間測定装置。     The delay time measuring device according to claim 1,
    A delay time measuring device further comprising a label embedding unit that embeds a plurality of labels into a packet, omitting a label of a node for which the shortest path is unique.
  4. 　請求項１に記載の遅延時間測定装置であって、
    　前記第１遅延時間測定部または前記第２遅延時間測定部で前記往復遅延時間を測定できなかったときにパケットロスと判定するパケットロス判定部をさらに備える
    ことを特徴とする遅延時間測定装置。     The delay time measuring device according to claim 1,
    A delay time measuring device further comprising a packet loss determining unit that determines a packet loss when the round trip delay time cannot be measured by the first delay time measuring unit or the second delay time measuring unit.
  5. 　請求項１に記載の遅延時間測定装置であって、
    　前記片道平均遅延時間演算部は、
    　　前記第１遅延時間測定部が測定した往復遅延時間を２で除算した片道平均遅延時間と前記第２遅延時間測定部が測定した往復遅延時間を２で除算した片道平均遅延時間とを加算して片道平均遅延時間を演算する第１演算と、
    　　前記第１遅延時間測定部が測定した往復遅延時間と前記第２遅延時間測定部が測定した往復遅延時間とを加算して、加算された往復遅延時間を２で除算して片道平均遅延時間を演算する第２演算と、
    　の何れか一方の演算を実行する
    ことを特徴とする遅延時間測定装置。     The delay time measuring device according to claim 1,
    The one-way average delay time calculation unit is
    Adding the one-way average delay time obtained by dividing the round-trip delay time measured by the first delay time measurement section by 2 and the one-way average delay time obtained by dividing the round-trip delay time measured by the second delay time measurement section by 2. a first calculation for calculating the one-way average delay time;
    The round-trip delay time measured by the first delay time measurement section and the round-trip delay time measured by the second delay time measurement section are added, and the added round-trip delay time is divided by 2 to obtain the one-way average delay time. a second operation to be performed;
    A delay time measuring device characterized in that it performs one of the following calculations.
  6. 　始点ノードと終点ノードとの間の測定区間で発生するパケット遅延時間を測定する遅延時間測定装置が実行する遅延時間測定方法であって、
    　前記遅延時間測定装置は、
    　前記測定区間を通過することなく、自装置と前記始点ノードとの間で発生する往復遅延時間を測定する第１遅延時間測定ステップと、
    　前記測定区間を通過することなく、前記自装置と前記終点ノードとの間で発生する往復遅延時間を測定する第２遅延時間測定ステップと、
    　自装置から前記測定区間を介して前記自装置まで戻るループの順方向遅延時間および該ループを逆方向に戻るまでの逆方向遅延時間の何れか一方または双方を測定する第３遅延時間測定ステップと、
    　前記第１遅延時間測定ステップで測定した第１往復遅延時間および前記第２遅延時間測定ステップで測定した第２往復遅延時間に基づいて、前記始点ノードと前記終点ノードとの間であって、前記自装置を経由した区間で発生する片道平均遅延時間を演算する片道平均遅延時間演算ステップと、
    　前記第３遅延時間測定ステップで前記順方向遅延時間を測定したとき、前記順方向遅延時間から前記片道平均遅延時間を減じて、前記測定区間の順方向遅延時間を演算し、前記第３遅延時間測定ステップで前記逆方向遅延時間を測定したとき、前記逆方向遅延時間から前記片道平均遅延時間を減じて、前記測定区間の逆方向遅延時間を演算する遅延時間演算ステップと
    を実行することを特徴とする遅延時間測定方法。     A delay time measurement method executed by a delay time measurement device that measures a packet delay time occurring in a measurement section between a start point node and a destination node, the method comprising:
    The delay time measuring device includes:
    a first delay time measuring step of measuring a round trip delay time occurring between the own device and the start point node without passing through the measurement section;
    a second delay time measuring step of measuring a round trip delay time occurring between the own device and the end point node without passing through the measurement section;
    a third delay time measuring step of measuring one or both of a forward delay time of a loop returning from the self-device to the self-device via the measurement section and a backward delay time of returning through the loop in the reverse direction; ,
    between the start point node and the end point node based on the first round trip delay time measured in the first delay time measuring step and the second round trip delay time measured in the second delay time measuring step, a one-way average delay time calculation step for calculating the one-way average delay time occurring in the section via the own device;
    When the forward delay time is measured in the third delay time measuring step, the one-way average delay time is subtracted from the forward delay time to calculate the forward delay time of the measurement section, and the third delay time is calculated by subtracting the one-way average delay time from the forward delay time. When the backward delay time is measured in the measuring step, the one-way average delay time is subtracted from the backward delay time to calculate the backward delay time of the measurement section. Delay time measurement method.
  7. 　請求項６に記載の遅延時間測定方法をコンピュータに実行させることを特徴とする遅延時間測定プログラム。
          A delay time measurement program that causes a computer to execute the delay time measurement method according to claim 6.
PCT/JP2022/022410 2022-06-02 2022-06-02 Delay time measurement device, delay time measurement method and delay time measurement program WO2023233606A1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
PCT/JP2022/022410 WO2023233606A1 (en) 2022-06-02 2022-06-02 Delay time measurement device, delay time measurement method and delay time measurement program

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/JP2022/022410 WO2023233606A1 (en) 2022-06-02 2022-06-02 Delay time measurement device, delay time measurement method and delay time measurement program

Publications (1)

Publication Number Publication Date
WO2023233606A1 true WO2023233606A1 (en) 2023-12-07

Family

ID=89026102

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2022/022410 WO2023233606A1 (en) 2022-06-02 2022-06-02 Delay time measurement device, delay time measurement method and delay time measurement program

Country Status (1)

Country Link
WO (1) WO2023233606A1 (en)

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20150023179A1 (en) * 2013-07-19 2015-01-22 Rad Data Communications Ltd. Triangle loopback

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20150023179A1 (en) * 2013-07-19 2015-01-22 Rad Data Communications Ltd. Triangle loopback

Similar Documents

Publication Publication Date Title
KR100716153B1 (en) Method for Measuring Stage-to-stage Delay in Nonsynchronization Packet Transfer Network, Nonsynchronization Packet Sender and Receiver
US6978223B2 (en) Systems and methods for network performance measurement using packet signature collection
Liu et al. Traffic engineering with forward fault correction
KR100597588B1 (en) Method for Measurement of Path characteristic between nodes using Active Testing Packet based Priority
JP5646090B2 (en) Traceroute_delay diagnostic command
KR100817798B1 (en) A method for estimating available bandwidth of network link using time stamp function of internet control message protocol
KR101504055B1 (en) Automatic capture of the network delay components
US7286482B2 (en) Decentralized SLS monitoring in a differentiated service environment
WO2008141574A1 (en) A method for establishing clock trace relationship and an equipment for computing clock trace relationship
US20170339039A1 (en) Method for devices in a network to participate in an end-to-end measurement of latency
BR112015029583B1 (en) METHOD FOR PERFORMING A MEASUREMENT OF A LINK, NODE FOR A COMMUNICATION NETWORK, COMMUNICATION NETWORK, AND COMPUTER READable STORAGE MEDIA
BR112015015221B1 (en) METHOD FOR ROUTE DATA IN A BIDIRECTIONAL COMMUNICATION SESSION THROUGH AN OVERLAY NETWORK BETWEEN A FIRST NODE AND A SECOND NODE
AU2005209770A1 (en) Method and apparatus for characterizing an end-to-end path of a packet-based network
GB2412033A (en) Traffic flow determination in communications networks
CN112005527A (en) Enabling performance measurements in a packet-switched communication network
CN112689977B (en) Techniques for collecting and transmitting telemetry information in a communication network
CN103155488A (en) Delay measurement system and delay measurement method, as well as delay measurement device and delay measurement program
WO2023233606A1 (en) Delay time measurement device, delay time measurement method and delay time measurement program
CN113508557A (en) Enabling round-trip packet loss measurement in a packet-switched communication network
JP7388535B2 (en) Delay measurement device, delay measurement method and program
JP5625992B2 (en) Quality estimation apparatus, quality estimation method and program
BRPI0619173A2 (en) process and remote control device of congestion of meshed streams exchanged in a telecommunication network
KR20150100027A (en) Method device for setting routing in software defined network
Cui et al. SCONE: A tool to estimate shared congestion among Internet paths
WO2018077435A1 (en) Method for supporting network monitoring in a software defined network and corresponding software defined network

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 22944888

Country of ref document: EP

Kind code of ref document: A1