Association device and association method

Abstract

An association device 1 includes an association unit 14 for associating a transmission device which has issued alarm information regarding path switching in a transmission section with a forwarding device in which a packet loss has been detected and a packet delay time has changed in the same time slot as the time slot in which the alarm information has been issued.

Description

Linking Device and Linking Method

[0001] The present disclosure relates to a linking device and a linking method.

[0002] In the operation management of the core network, it is necessary to accurately grasp the connection relationship between the transfer layer and the transmission layer.

[0003] Therefore, there is a method of grasping the connection relationship based on the fluctuation of the optical power in the transmission device associated with the ON / OFF of the communication port of the transfer device (Non-Patent Document 1). In addition, there is a method of regarding a transfer device and a transmission device in which the transmission / reception traffic volume of the transfer device and the reception / transmission traffic volume of the transmission device match each other as having a connection relationship (Non-Patent Document 2).

[0004] 西口、外4名、“IP・光ネットワークにおけるレイヤ / ドメイン間の接続関係把握方式”、電子情報通信学会、ソサイエティ大会、2023年9月、B-12-1丹治、外3名、“トラフィック量を用いたネットワークトポロジー推定技術の検討”、電子情報通信学会、信学技報、ICM2012-75、2013年3月、p.95-p.100

[0005] However, in the method of Non-Patent Document 1, since the communication port of the transfer device is turned ON / OFF, it affects the user, so it cannot be implemented in the operating core network. In the method of Non-Patent Document 2, the transmission device must have a function of calculating the traffic volume.

[0006] The present disclosure has been made in view of the above circumstances, and an object of the present disclosure is to provide a technique capable of easily grasping the connection relationship between the transfer layer and the transmission layer.

[0007] A linking device according to one aspect of the present disclosure includes a linking unit that links a transmission device that has issued alarm information on path switching in a transmission section and a transfer device in which packet loss has been detected and the delay time of packets has fluctuated in the same time zone as the time zone in which the alarm information was issued.

[0008] One aspect of the present disclosure is a linking method performed by a linking device, in which a transmission device that issued a route switching alarm for a transmission section is linked to a forwarding device in which packet loss was detected and the packet delay time changed during the same time period in which the alarm was issued.

[0009] According to this disclosure, the connection relationship between the transfer layer and the transmission layer can be easily understood.

[0010] Figure 1 shows an example of the configuration of the linking system. Figure 2 is a flowchart showing an example of the operation of the verification unit. Figure 3 shows an image of the communication verification. Figure 4 is a flowchart showing an example of the operation of the collection unit. Figure 5 shows an image of the alarm information collection. Figure 6 is a flowchart showing an example of the operation of the linking unit. Figure 7 shows an image of the alarm information. Figure 8 shows an image of the delay time. Figure 9 shows an image of the linking process. Figure 10 shows an example of the hardware configuration of the linking device.

[0011] Embodiments of this disclosure will be described below with reference to the drawings. In the drawings, the same parts are denoted by the same reference numerals and their descriptions are omitted.

[0012] [Summary of this disclosure] This disclosure describes a method for mechanically determining the connection relationship between the forwarding layer and the transmission layer without adding new functions to the forwarding and transmission equipment within the core network. Specifically, it uses information generated during route switching of transmission sections, which is performed during installation work or in the event of transmission line failures during operation, to determine the connection relationship between the two layers.

[0013] Two possible routing patterns for the transmission section are: Pattern 1, in which the transfer device switches the route from system 0 (active system) to system 1 (backup system); and Pattern 2, in which the transmission section switches the route from the Work system (active system) to the Protection system (backup system).

[0014] Pattern 1; Before route switching: Transfer device R1 - Transmission device T1 - Transmission device T2 - Transfer device R2 After route switching: Transfer device R1 - Transfer device R3 - Transmission device T3 - Transmission device T4 - Transfer device R4 - Transfer device R2 Pattern 2; Before route switching: Transfer device R1 - Transmission device T1 - Transmission device T2 - Transfer device R2 After route switching: Transfer device R1 - Transmission device T3 - Transmission device T4 - Transfer device R2 In either pattern, the packet delay time at the transfer device fluctuates due to the difference in optical fiber length caused by route switching in the transmission section. In addition, packet loss is detected when communication between transfer devices is checked due to momentary interruptions caused by route switching in the transmission section. Furthermore, alarm information indicating route switching in the transmission section is issued when route switching in the transmission section occurs.

[0015] Therefore, in this disclosure, during route switching of the transmission section, the detection of packet delay time fluctuations and packet loss at the forwarding layer and alarm information indicating route switching of the transmission section at the transmission layer are matched and the forwarding device and the transmission device are associated with each other.

[0016] [Example of Linking System Configuration] Figure 1 shows an example of the configuration of the linking system according to this embodiment. The linking system comprises a linking device 1 and a maintenance terminal 2.

[0017] The linking device 1 is communicated to multiple transfer devices 3 that constitute the transfer layer. The linking device 1 is also communicated to a maintenance device 5 that maintains multiple transmission devices 4 that constitute the transmission layer. The linking device 1 is a device that calculates which transmission device 4 each transfer device 3 is associated with (linked to).

[0018] Maintenance terminal 2 is connected to linking device 1 in a communication-enabled manner. Maintenance terminal 2 is a terminal used by maintenance personnel when maintaining the transfer layer and transmission layer. For example, maintenance terminal 2 may be a personal computer or a tablet device.

[0019] [Example of the configuration of the linking device] As shown in Figure 1, the linking device 1 comprises a verification unit 11, a collection unit 12, a storage unit 13, and a linking unit 14.

[0020] The verification unit 11 has a function to periodically check whether or not there is communication between the multiple transfer devices 3.

[0021] The collection unit 12 has the function of periodically collecting alarm information issued from multiple transmission devices 4 from the maintenance device 5.

[0022] The storage unit 13 has a function to store communication confirmation information, which is the confirmation of whether or not communication exists between the transfer devices 3 by the confirmation unit 11. The storage unit 13 also has a function to store alarm information (alarm information issued from multiple transmission devices 4) collected from the maintenance device 5.

[0023] The linking unit 14 has the function of linking the transmission device 4, which issued an alarm information for route switching in the transmission section, with the forwarding device 3, which detected packet loss and experienced a change in packet delay time during the same time period in which the alarm information was issued. Specifically, it has the following functions.

[0024] The linking unit 14 reads out alarm information indicating a route switch in the transmission section from the alarm information stored in the storage unit 13, and has the function of identifying the transmission device 4 in which a route switch in the transmission section has occurred using the alarm information.

[0025] The linking unit 14 reads communication confirmation information from the storage unit 13 and uses this communication confirmation information to identify the forwarding device 3 in which packet loss was detected and the packet delay time fluctuated during the same time period as the route switching alarm information was issued.

[0026] The linking unit 14 has the function of linking the specified transmission device 4 and the specified transfer device 3 to each other.

[0027] The linking unit 14 has a function to transmit the linking result to the maintenance terminal 2.

[0028] [Example of operation of the linking device] (Example of operation of the verification unit) An example of operation of the verification unit 11 will be explained. Figure 2 is a flowchart showing an example of operation of the verification unit 11.

[0029] First, as shown in Figure 3, the verification unit 11 accesses the transfer device 3 to be checked for communication, which is described in the control information, and checks whether communication is possible with a predetermined transfer device 3' for each communication port of the transfer device 3 (step S101).

[0030] Finally, the verification unit 11 registers the verification results, that is, the communication verification results for each communication port performed by the transfer device 3 that is the target of the communication verification, in the storage unit 13 (step S102).

[0031] The verification unit 11 periodically executes steps S101 to S102 for all transfer devices 3 that are subject to communication verification as described in the control information, according to the measurement cycle described in the control information.

[0032] This allows connectivity confirmation information for each transfer device and communication port to be registered in chronological order. The connectivity confirmation information includes, for example, the transfer device ID, the communication port ID, the measurement time, whether connectivity was established or not, and the delay time. The transfer devices to be checked and the measurement cycle can be arbitrarily changed within the control information.

[0033] (Example of operation of the collection unit) An example of operation of the collection unit 12 will be explained. Figure 4 is a flowchart showing an example of operation of the collection unit 12.

[0034] First, as shown in Figure 5, the collection unit 12 collects alarm information that was sent from multiple transmission devices 4 to the maintenance device 5 from the maintenance device 5 (step S201).

[0035] Finally, the collection unit 12 registers the alarm information in the storage unit 13 (step S202).

[0036] The collection unit 12 periodically executes steps S201 to S202.

[0037] (Example of operation of the linking unit) An example of operation of the linking unit 14 will be explained. Figure 6 is a flowchart showing an example of operation of the linking unit 14.

[0038] Step S301: First, the linking unit 14 reads out the alarm information indicating the path switching of the transmission section from the alarm information stored in the storage unit 13. Then, the linking unit 14 uses the alarm information to identify the transmission device 4 in which the path switching of the transmission section has occurred in terms of communication ports.

[0039] Step S302: Next, the linking unit 14 reads out the connectivity confirmation information from the storage unit 13. Then, the linking unit 14 uses the connectivity confirmation information to identify the transfer device 3 in which packet loss has been detected and the packet delay time has fluctuated around the time when the alarm information of path switching was issued in terms of communication ports.

[0040] Step S303: Next, the linking unit 14 links the communication port of the transmission device 4 identified in Step S301 with the communication port of the transfer device 3 identified in Step S302.

[0041] Step S304: Finally, the linking unit 14 transmits the linking result (the linking result between the communication port of the transmission device 4 and the communication port of the transfer device 3) linked in Step S303 to the maintenance personnel terminal 2.

[0042] (Specific example of the operation example of the linking device) A specific example of the operation example of the linking device 1 will be described.

[0043] The alarm information stores transmission device information (host name, communication port, etc.), transmission device alarm types (path grade, alarm type, importance, etc.). An image of the alarm information is shown in FIG. 7. Optical path information and communication port information of the transmission device are also stored.

[0044] When a transmission line failure occurs, the linking unit 14 selects an alarm type that can determine that it is a path switching of the transmission section, and acquires the device information of the transmission device that is the alarm source. Then, the linking unit 14 identifies the transmission device in which the path switching has occurred in terms of communication ports from the selected and acquired information.

[0045] Also, at the time of a recovery alarm, the linking unit 14 selects an alarm type that can determine that it is a path switching of the transmission section, and acquires the device information of the transmission device that is the alarm source. Then, the linking unit 14 identifies the transmission device in which the path switching has occurred in terms of communication ports from the selected and acquired information.

[0046] When a route switch in the transmission section has occurred, the delay time as imaged in FIG. 8 can be grasped from the communication confirmation result. During the time period between before and after the route switch, packet loss has been detected by the transfer device due to a momentary interruption in the transmission section. Also, before and after the route switch, the delay time of the packet varies in the transfer device due to the difference in the optical fiber length caused by the route switch in the transmission section.

[0047] Therefore, when a transmission line failure occurs, the linking unit 14 checks from the communication confirmation results for each communication port between transfer devices that the confirmation unit 11 regularly executes, whether packet loss has been detected in the transfer device or whether the result of the delay measurement has fluctuated, in the time periods before and after the occurrence of the transmission line failure.

[0048] Also, at the time of a recovery alarm, the linking unit 14 checks from the communication confirmation results for each communication port between transfer devices that the confirmation unit 11 regularly executes, whether packet loss has been detected in the transfer device or whether the result of the delay measurement has fluctuated, in the time periods before and after the recovery alarm.

[0049] Then, as shown in FIG. 9, the linking unit 14 performs consistency analysis on the connection relationship between the communication port of the specified transfer device and the communication port of the confirmed transfer device at the time of route switch. That is, if the time of the alarm information, the time period of the detection of packet loss, and the time period of the fluctuation of the delay time are all included in the same time period, the linking unit 14 determines that the communication port of the transfer device and the communication port of the transfer device included in the same time period are in a connection relationship (linked).

[0050] If the fluctuation of the delay time is minute and it is impossible to determine whether a route switch has occurred, the linking unit 14 performs consistency analysis only based on the presence or absence of the detection of packet loss. If consistency analysis cannot be performed only based on the presence or absence of the detection of packet loss, the linking unit 14 does not perform consistency analysis processing and determines that no route switch has occurred.

[0051] [Effects] As described above, according to this embodiment, the transmission device that issued the alarm information for route switching in the transmission section and the forwarding device that detected packet loss and experienced a change in packet delay time during the same time period in which the alarm information was issued are linked to each other. Therefore, even in a core network in operation, the connection relationship between the forwarding layer and the transmission layer can be easily understood.

[0052] In other words, because it uses the results of connectivity checks between general-purpose IP routers and alarm information from transmission devices, there is no need to add functions as with conventional technologies. Therefore, it can be applied even to devices that are already in operation if a route switch occurs in the transmission section. It is also effective in quickly isolating network failures and understanding their impact.

[0053] [Other] This disclosure is not limited to the embodiments described above. This disclosure can be modified in numerous ways within the scope of the gist of this disclosure.

[0054] The linking device 1 of this embodiment described above can be realized using a general-purpose computer system that includes, for example, a CPU 901, a memory 902, a storage 903, a communication device 904, an input device 905, and an output device 906, as shown in Figure 10.

[0055] Memory 902 and storage 903 are storage devices. In this computer system, each function of the linking device 1 is realized when the CPU 901 executes a predetermined program loaded onto memory 902.

[0056] The linking device 1 may be implemented on a single computer. The linking device 1 may be implemented on multiple computers. The linking device 1 may be a virtual machine implemented on a computer.

[0057] The program for the linking device 1 can be stored on a computer-readable recording medium such as an HDD, SSD, USB memory, CD, or DVD. A computer-readable recording medium is, for example, a non-transitory recording medium. The program for the linking device 1 can also be distributed via a communication network.

[0058] 1. Linking device 11. Verification unit 12. Collection unit 13. Storage unit 14. Linking unit 2. Maintenance terminal 3. Transfer device 4. Transmission device 5. Maintenance device 901. CPU 902. Memory 903. Storage 904. Communication device 905. Input device 906. Output device

Claims

1. A linking device comprising a linking unit that links a transmission device that issued an alarm information for route switching in the transmission section with a forwarding device that detected packet loss and experienced a change in packet delay time during the same time period in which the alarm information was issued.

2. The linking device according to claim 1, comprising: a confirmation unit that periodically checks whether communication exists between multiple transfer devices; a collection unit that periodically collects alarm information issued from multiple transmission devices; and a storage unit that stores communication confirmation information confirming whether communication exists between the transfer devices and stores the alarm information, wherein the linking unit identifies a transmission device where a route switch in the transmission section has occurred using the alarm information indicating a route switch in the transmission section, identifies a transfer device where packet loss was detected and the packet delay time fluctuated during the same time period as when the alarm information was issued using the communication confirmation information, and links the transmission device with the transfer device.

3. A linking method performed by a linking device, which links a transmission device that issued an alarm information for route switching in a transmission section with a forwarding device that detected packet loss and experienced a change in packet delay time during the same time period in which the alarm information was issued.

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