JP2013207495A - Line monitoring method and scheme - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a line monitoring method and scheme that can surely detect dead or alive of a line in a short time while reducing consumption of line bandwidth by minimizing generation of monitoring traffic.SOLUTION: A transmission side communication device 1a and a reception side communication device 1b are mutually connected with a physical line L. The reception side communication device 1b dynamically and adaptively sets the transmission cycle (monitoring cycle) ΔT of a monitoring signal St transmitted and received through the line L on the basis of the monitoring sensitivity of a communication service being provided on the physical line L. As the monitoring sensitivity, the index of real time performance requested to each communication service can be used, and the monitoring sensitivity of communication services requested a higher real time performance like VoIP and video reproduction is made higher than that of communication services requested a lower real time performance like email and Web browsing. If a plurality of different communication services are provided in parallel on the line L, the monitoring cycle ΔT is set on the basis of a communication service, the monitoring sensitivity of the communication service being the highest among them.

Description

  The present invention relates to a line monitoring method and method for determining the life and death of a monitoring line that connects a communication device on a transmission side and a communication device on a reception side, and in particular, based on a communication service provided on the monitoring line. TECHNICAL FIELD The present invention relates to a line monitoring method and method in which the network is dynamically changed.

  Patent Document 1 discloses a technique for reducing the processing load of the central processing unit by means for distributing and monitoring the life and death of the line by the line monitoring unit and the central processing unit. The line status (up / down) is used to determine whether the line is active or not.

  Japanese Patent Application Laid-Open No. 2004-228561 discloses a technique for determining a used / unused state of a line by monitoring a signal synchronization state of the line that is locally connected to the communication apparatus with a counter communication apparatus. Here, the synchronization valid / invalid determination bit added to the received message is read, and if the synchronization determination bit is invalid, it is determined to be unused, and if the synchronization determination bit continues to be valid for a certain number of times, It is determined that the line is being used.

  Patent Document 3 discloses a technique for periodically sending an inquiry message to a terminal and determining the execution state (operation / stop) of the terminal based on whether or not there is a response in order to monitor whether the terminal is active or not.

  Patent Document 4 discloses a technique in which an OLT connected to an ONU determines the communication state of an optical fiber based on the presence or absence of a received signal.

JP 2008-22188 A JP 2001-251423 A JP 2005-323238 A JP 2009-177510 A

  In the above-described conventional technology, there is a limit to the life and death judgment. That is, in Patent Document 1, it is not possible to determine that communication is impossible in a situation where communication is not possible even though the line is up. In Patent Documents 2 and 4, when there is no communication from the opposite communication device, it is not possible to determine whether the line is active or not. In Patent Document 3, if the technique is applied to line monitoring, if it is desired to detect a line failure in a short period of time, a large amount of inquiry messages are transmitted, so the line consumption band increases.

  An object of the present invention is to solve all the above-mentioned problems of the prior art, and a line monitoring method capable of reliably detecting the life and death of a line in a short time while reducing the consumption of the line by minimizing the occurrence of monitoring traffic. And to provide a formula.

  In order to achieve the above object, the present invention is characterized in that the following configuration is provided in a line monitoring method for determining the life and death of a monitoring line that connects a communication device on a transmission side and a communication device on a reception side. There are features.

  (1) Identification means for identifying the communication service provided on the monitoring line, monitoring period calculation means for calculating the monitoring period based on the identification result, and communication from the reception side to the transmission side of the monitoring signal request including the monitoring period The monitoring signal requesting means for transmitting to the apparatus, the monitoring signal transmitting means for transmitting the monitoring signal from the transmitting side to the receiving side communication apparatus in the monitoring period, and the monitoring response returned to the monitoring signal or the monitoring signal are normal A life / non-life judging means for judging the life / non-life of the monitoring line based on whether it is received or not.

  (2) The life / death determining means determines whether the monitoring line is alive based on whether or not the monitoring signal is received in a cycle corresponding to the monitoring cycle in the communication device on the receiving side.

  (3) The alive determination means determines whether the monitoring line is alive based on whether a monitoring response is received with respect to the monitoring signal in the communication device on the transmission side.

  (4) The monitoring cycle calculation means calculates the monitoring cycle so that the monitoring cycle of the monitoring line that provides the communication service with higher real-time property becomes shorter.

  (5) The monitoring period calculation means calculates the monitoring period based on the communication service having the highest real-time property when a plurality of communication services are provided on the monitoring line.

  (6) A monitoring signal superimposing unit that superimposes the monitoring signal on the signal transmitted to the communication device on the receiving side at a timing corresponding to the monitoring cycle is further provided.

According to the present invention, the following effects are achieved.
(1) The monitoring signal transmission cycle (monitoring cycle) sent and received on the monitored line is not fixed, but is adaptively set based on the communication service provided on the line. The monitoring cycle can be optimized according to the changing status of the monitoring line. Accordingly, it is possible to prevent the monitoring signal from being transmitted more than necessary because the monitoring cycle becomes too short, or the monitoring cycle from becoming too long, thereby reducing both the consumption band and improving the monitoring accuracy.

  (2) Since the monitoring cycle of the monitoring line that provides communication services with higher real-time characteristics is shortened, it is possible to reduce the bandwidth consumption and improve the monitoring accuracy for line defects that affect the user's quality of experience. It becomes possible to detect while making it compatible.

  (3) When multiple communication services are provided on the monitoring line, the monitoring cycle is calculated based on the communication service with the highest real-time performance. Bandwidth reduction and monitoring accuracy can be improved at the same time.

  (4) Since the monitoring signal is transmitted by being superimposed on the transmission signal, the consumption band of the monitoring signal can be reduced without degrading the monitoring accuracy.

It is the sequence flow which showed the operation | movement outline | summary of this invention. It is a functional block diagram of the communication apparatus which concerns on one Embodiment of this invention. It is a block diagram of the transmission flow of the user data in the communication apparatus on the transmission side. It is a block diagram of the reception flow of the user data in the communication apparatus on the receiving side. It is a block diagram of the production | generation of a monitoring signal in the communication apparatus of a transmission side, and a transmission flow. It is a block diagram of a line failure determination flow in the communication device on the receiving side. It is a functional block diagram showing an example of a network configuration to which the second embodiment is applied. This is a main flow common to each communication device. It is the flowchart which showed the operation | movement intrinsic | native to a transmission side function. It is the flowchart which showed the operation | movement peculiar to a relay function. It is the flowchart which showed the operation | movement intrinsic | native to a receiving side function.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a sequence flow showing an outline of the operation of the present invention, in which a communication device 1a on the transmission side and a communication device 1b on the reception side are connected to each other via a physical line L. Each communication device 1 is, for example, an Ethernet (registered trademark) switch or a router, and is equipped with a line monitoring function according to the present invention.

  The communication device 1b on the receiving side, based on the monitoring sensitivity of the communication service (application) provided on the physical line L, transmits the transmission cycle of the monitoring signal St transmitted / received on the line L (hereinafter also referred to as a monitoring cycle). (Yes) ΔT is set dynamically and adaptively. As the monitoring sensitivity, an index of real-time characteristics required for each communication service can be used, and the monitoring sensitivity of a communication service with high real-time characteristics such as VoIP and video playback can be used for e-mail and web browsing. Thus, the demand for real-time performance is higher than that of communication services. The monitoring cycle ΔT is set to be shorter for lines that are providing communication services with high monitoring sensitivity.

  When a plurality of different communication services are provided in parallel on the line L, the monitoring period ΔT is set based on the communication service having the highest monitoring sensitivity among them. Therefore, the monitoring period ΔT is set based on the monitoring sensitivity of video playback for a line that is providing video playback and e-mail communication services.

[First embodiment]
Referring to FIG. 1, at time t1, the monitoring cycle ΔT1 is set based on the communication service being provided on the physical line L in the communication device 1b on the receiving side. At time t2, a monitoring signal request message in which the monitoring period ΔT1 is described is transmitted from the receiving communication apparatus 1b to the transmitting communication apparatus 1a. At time t3, the transmission cycle of the monitoring signal St is set to the monitoring cycle ΔT1 in the communication device 1a on the transmission side. At time t4, transmission of the monitoring signal St is started, and thereafter, transmission of the monitoring signal St is repeated at the monitoring period ΔT1. In the communication device 1b on the receiving side, the reception determination of the monitoring signal St is performed, and it is determined that no line failure has occurred as long as the reception cycle is equal to the monitoring cycle ΔT1.

  Note that the monitoring signal St may be transmitted alone, but if it is superimposed on the data transmitted by the communication service being provided, the generation of monitoring traffic can be minimized. That is, if the VoIP service is being provided, the monitoring signal St may be superimposed on the voice data packet.

  On the other hand, when the provided service is changed (addition or termination of the provided service) at time t5, the monitoring cycle ΔT is reset based on the changed communication service at time t6. Here, the description will be continued assuming that the monitoring period is changed from ΔT1 to ΔT2.

  At time t7, a monitoring signal request message in which the monitoring period ΔT2 after the change is described is transmitted from the receiving communication apparatus 1b to the transmitting communication apparatus 1a. At time t8, the transmission cycle of the monitoring signal St is updated to the monitoring cycle ΔT2 in the communication device 1a on the transmission side. At time t9, transmission of the monitoring signal St is resumed, and thereafter, transmission of the monitoring signal St is repeated at the monitoring period ΔT2. In the communication apparatus 1b on the receiving side, it is determined that no line failure has occurred as long as the reception cycle of the monitoring signal St is equal to the monitoring cycle ΔT2, and it is determined that a line failure has occurred if it exceeds the monitoring cycle ΔT2. .

  FIG. 2 is a functional block diagram of the communication device 1 according to an embodiment of the present invention. Here, the communication devices 1 on the transmission side and the reception side have the same configuration, and the function as the transmission side and the reception side Will be described as having both functions.

  The communication service unit 101 processes a packet transmitted / received by a communication service provided on the line L, and calculates a “communication service processing identifier”, “monitoring sensitivity”, and “opposite communication device identifier” for each communication service. To the unit 103. The “communication service processing identifier” is an identifier for distinguishing a communication service being provided on the line L, and is a value unique to each ward communication service. The “communication device identifier” is an identifier of a device or a communication port specified by a communication system protocol. For Ethernet (registered trademark), a MAC address corresponds to the communication device identifier. “Monitoring sensitivity” is associated with each communication service in advance.

  The user data forming unit 102 forms user data passed from the communication service unit 101 into transmission data that can be transmitted to the line L. The data buffer / monitoring signal multiplexing unit 104 is provided for each output port of the communication device 1, and functions other than the well-known function for buffering transmission data and sequentially passing the data to the signal transmission unit 105 are as follows. It has two functions.

  The first function adds a monitoring signal flag to only the data transmitted at the timing of the monitoring period ΔT among the data transmitted from the buffer to generate a monitoring signal. If transmission data does not stay in the buffer, monitoring signal data is newly generated. Hereinafter, the transmission data and the monitoring signal data converted into the monitoring signal are collectively referred to as “monitoring signal St”. The monitoring signal St includes an identifier (address) of the transmission source and the destination. For the resolution of the identifier, a general-purpose function of a communication system to which the present invention is applied is used. The second function receives a monitoring signal request message from the receiving-side communication device 1b and stores it in a buffer.

  The monitoring signal interval calculation unit 103 calculates the monitoring period ΔT based on the monitoring sensitivity of each communication service, and transmits the calculation result to the data buffer / monitoring signal multiplexing unit 104. In the present embodiment, a value obtained by dividing the monitoring sensitivity by the monitoring signal redundancy given in advance is set as the monitoring period ΔT. It is assumed that the monitoring signal redundancy is a value larger than 1 and is statically given to each communication device 1.

  The monitoring signal interval calculation unit 103 further transmits the triplet of “communication service processing identifier”, “monitoring sensitivity”, and “opposite communication device identifier” acquired from the communication service unit 101 to the line alive determination unit 110. Furthermore, the four sets of “communication service processing identifier”, “opposite communication device identifier”, “monitoring sensitivity”, and “monitoring period ΔT” are stored. That is, the monitoring signal interval calculation unit 103 executes the following processes (1) to (5).

  (1) A pair of “communication service processing identifier”, “monitoring sensitivity”, and “opposite communication device identifier” is received from the communication service unit 101 for each communication service being provided.

  (2) The monitoring period ΔT is calculated based on the monitoring sensitivity of the communication service being provided.

  (3) For each communication service being provided, a pair of “communication service identifier”, “opposite communication device identifier”, “monitoring sensitivity”, and “monitoring period ΔT” is stored.

  (4) The calculation result of the monitoring period ΔT is passed to the data buffer / monitoring signal multiplexing unit 104. At this time, an identifier unique to the monitoring request data is included to distinguish it from the user data.

  (5) A pair of “communication service processing identifier”, “monitoring sensitivity” and “opposite communication device identifier” is passed to the line alive determination unit 110.

  The signal transmission unit 105 transmits user data, a monitoring signal, and a monitoring signal request message by a known method. The signal receiving unit 106 receives user data, a monitoring signal, and a monitoring signal request message by a known method and passes them to the data / monitoring signal separation unit 109. The data / monitoring signal separation unit 109 reads an identifier for distinguishing the type of the received data, and distributes each data to the user data restoration unit 112, the line alive determination unit 110, and the monitoring request data decoding unit 108.

  The monitoring request data decoding unit 108 extracts the monitoring period ΔT from the monitoring signal request and passes the “monitoring signal interval” and “opposite communication device identifier” pair to the monitoring signal generation unit 107. At this time, the opposite communication device identifier is the identifier (address) of the opposite communication device included in the monitoring signal request. The monitoring signal generation unit 107 gives a monitoring signal transmission trigger to the data buffer / monitoring signal multiplexing unit 104 at the timing of the monitoring period ΔT. Since the plurality of opposing communication devices have different monitoring signal intervals, the monitoring signal transmission timing is managed by the scheduler. When a transmission trigger is given, the data buffer / monitor signal multiplexing unit 104 provided for each communication port by the opposite communication device is selected.

  The line alive determination unit 110 compares a predetermined monitoring period ΔT with the reception period of the monitoring signal St, and issues an alarm to the line failure handling unit 111 when the reception period of the monitoring signal St deviates from the monitoring period ΔT. I will inform you. The user data restoration unit 112 restores the received user data to the same data in the communication service process of the user data transmission device.

  Next, a procedure for realizing line monitoring in cooperation with the above-described units will be described in detail. In the present embodiment, line monitoring is realized by a combination of the following four data processing flows. In each figure, the block and step number related to the communication device 1a on the transmitting side are given a suffix a, and the block and step number related to the communication device 1b on the receiving side are given a suffix b to distinguish them. Separated. In addition, the configuration unnecessary for the description for each flow is displayed in gray.

(1) User Data Transmission Flow FIG. 3 is a block diagram for explaining a user data transmission operation in the communication device 1a on the transmission side. In step S1a, user data is passed from the communication service unit 101a to the user data forming unit 102a. In the user data forming unit 102a, the user data is converted into transmission data having a data structure that can be transmitted to the line L. In step S2a, the transmission data is transferred from the user data forming unit 102a to the data buffer / monitor signal multiplexing unit 104a. In step S3a, the transmission data is transferred from the data buffer / monitor signal multiplexing 104a to the signal transmission unit 105a. In step S4a, the transmission data is transmitted from the signal transmission unit 105a to the line L.

  (2) Monitoring cycle notification flow

  FIG. 4 is a block diagram for explaining an operation of receiving user data in the communication device 1b on the receiving side. In step S1b, data transmitted from the communication device 1a on the transmission side is received by the signal receiving unit 106b. In step S2b, the received data is passed from the signal receiving unit 106b to the data / monitor signal separating unit 109b. In step S3b, the received data is transferred from the data / monitor signal separation unit 109b to the user data restoration unit 112b and restored. In step S4b, the restored received data is transferred to the communication service unit 10b and processed appropriately.

  In step S5b, the monitoring sensitivity of the communication service that processes the received data is transmitted from the communication service unit 101b to the monitoring signal interval calculation unit 17b. At this time, if the line L is providing a plurality of communication services (for example, VoIP, video data, and e-mail), the monitoring sensitivity is transmitted for each communication service. The monitoring signal interval calculation unit 103b calculates the monitoring period ΔT based on the notified monitoring sensitivity. At this time, if a plurality of communication services are being provided as described above, the monitoring period ΔT is calculated based on the highest monitoring sensitivity.

  In step S6b, the monitoring period ΔT is passed to the monitoring signal multiplexing unit 104b and multiplexed into a monitoring signal request message transmitted to the communication device 1a on the transmission side. In step S7b, a monitoring signal request message including the monitoring period ΔT is passed to the signal transmission unit 105b. In step S8b, the monitoring signal request message is transferred to the communication device 1a on the transmission side. In step S9b, in parallel with these processes, the monitoring cycle ΔT is passed to the line alive determination unit 110b.

  (3) Monitoring signal transmission flow

  FIG. 5 is a block diagram for explaining the generation of the monitoring signal and the transmission operation thereof in the communication device 1a on the transmission side. In step S5a, the monitoring signal request message is received by the signal receiving unit 106a. In step S6a, the message is passed to the received data / monitor signal separation unit 109a. In step S7a, the monitoring cycle ΔT described in the monitoring signal request message is extracted in the monitoring request data decoding unit 108a. In step S8a, the monitoring period ΔT is passed to the monitoring signal generator 107a.

  In step S9a, the monitoring signal generation unit 20b generates the monitoring signal St in the notified monitoring period ΔT and sends it to the data buffer / monitoring data signal multiplexing unit 104a. In step S10a, the monitoring signal St is passed to the signal transmission function 105a. In step S11a, the monitoring signal St is transmitted to the receiving-side communication device 1b with a monitoring period ΔT.

  (4) Line failure judgment flow

  FIG. 6 is a block diagram for explaining the operation of determining a line failure in the communication device 1b on the receiving side. In step S9b, data transmitted from the communication device 1a on the transmission side is received by the signal receiving unit 106b. In step S10b, the received data is passed from the signal receiving unit 106b to the data / monitor signal separating unit 109b and separated into the received data and the monitor signal St. In step S11b, the separated received data is transferred to the user data restoration unit 112b and restored. In step S12b, the restored received data is transferred to the communication service unit 10b and processed appropriately.

  In parallel with this, in step S13b, the separated monitoring signal St is passed to the line alive monitoring determination unit 21b, and it is determined whether or not the line with the transmission side communication device 1a is normal. . When the monitoring signal St cannot be normally received in the monitoring period ΔT, the line alive monitoring determination unit 21b notifies the line failure handling unit 111b of the occurrence of the line failure in step S14b. In response to the notification of the occurrence of the line failure, the line failure handling unit 111b executes a scheduled line failure handling process.

  According to the present embodiment, the transmission period (monitoring period ΔT) of the monitoring signal transmitted and received on the line L is not fixed, but is adaptively set based on the communication service provided on the line. The monitoring cycle can be optimized according to the status of the monitoring line that changes every moment. Accordingly, it is possible to prevent the monitoring signal from being transmitted more than necessary because the monitoring cycle becomes too short, or the monitoring cycle from becoming too long, thereby reducing both the consumption band and improving the monitoring accuracy.

  In addition, since the monitoring cycle ΔT is shortened for lines that provide communication services with higher real-time characteristics, it is possible to reduce the bandwidth consumption and improve the monitoring accuracy for line defects that affect the quality of user experience. It becomes possible to detect while making it compatible.

  In addition, when multiple communication services are provided on line L, the monitoring cycle is calculated based on the communication service with the highest real-time performance. It is possible to achieve both a reduction in monitoring and an improvement in monitoring accuracy.

  Furthermore, if the monitoring signal St is superimposed on the transmission signal and transmitted, the consumption band of the monitoring signal can be reduced without lowering the monitoring accuracy.

[Second Embodiment]
Next, a second embodiment of the present invention will be described. In the first embodiment described above, the life and death of the physical line L that directly connects the communication devices 1a and 1b on the transmission side and the reception side are the objects of determination, but the present invention is not limited to this. In addition, the present invention can be similarly applied to the life / death determination of a path established between the transmission-side and reception-side communication devices 1a and 1b via a plurality of communication devices.

  FIG. 7 is a functional block diagram showing an example of a network configuration to which the second embodiment is applied. Six communication apparatuses 3 to 8 are connected by physical lines L1 to L5. Here, the communication device 3 on the transmission side communicates with the communication device 7 on the reception side via the route R1 via the communication devices 5 and 6 for relay, and the communication device 4 on the transmission side communicates with the communication device 8 on the reception side for relay. A case where communication is performed via the route R2 via the communication devices 5 and 6 will be described as an example.

  In this embodiment, in the lines L1 and L4 through which only the route R1 passes, the monitoring period ΔT1 is set based on the monitoring sensitivity of the communication service provided by the route R1, and in the lines L2 and L5 through which only the route R2 passes. The monitoring cycle ΔT2 is set based on the monitoring sensitivity of the communication service provided by the route R2. On the other hand, in the line L3 through which the paths R1 and R2 pass, the monitoring period ΔT3 is set based on the monitoring sensitivity of the communication service provided by the paths R1 and R2.

  8 to 11 are flowcharts showing the operation of each communication apparatus in the present embodiment. Also in this embodiment, each communication device 1 has the same configuration, and has all of a transmission side function, a relay function, and a reception side function. FIG. 8 is a main flow common to each communication device, FIG. 9 is a flowchart showing an operation specific to the transmission side function, and FIG. 10 is a flowchart showing an operation specific to the relay function. FIG. 11 is a flowchart showing an operation specific to the reception side function.

  First, referring to FIG. 8, when a monitoring request is detected in step S51, it is determined in step S52 whether the request source is a communication device adjacent to the upper layer or the upstream side of the communication service unit 100. The In the case of the communication device 3 (4) on the transmission side, the request source is determined to be the upper layer of the communication service unit 101, and thus the process proceeds to step S54 and the operation starts in the operation mode unique to the transmission side.

  FIG. 9 is a flowchart of the “transmission side mode” executed by the transmission side communication device 3 (4). In step S100, the downstream side of the route R1 is based on the route table created when the route R1 is established. The relay communication device 5 adjacent to is searched. In step S <b> 101, a monitoring request destined for the receiving communication device 7 is transmitted to the relay communication device 5.

  In step S102, it is determined whether or not a response to the monitoring request is returned from the downstream relay communication device 5. If a monitoring response (ACK) is returned, the process proceeds to step S103, and the process proceeds to step S104 after receiving the monitoring period ΔT notified from the relay communication device 5 in response to the monitoring request. On the other hand, if a monitoring response is not returned within a predetermined time, there is a possibility that a failure has occurred on the downstream side of the route, so the process proceeds to the failure handling process in step S106.

  In step S104, the monitoring signal generation unit 107 generates a monitoring signal St at the monitoring period ΔT, and the data buffer / monitoring signal multiplexing unit 104 superimposes it on user data and transmits it from the signal transmission unit 105. .

  Returning to FIG. 8, in the relay communication device 5 (6), in step S 51, when reception of the monitoring request transmitted by the transmission side communication device 3 (4) in step S 101 is detected, in step S 52, the request source Is determined to be a communication device adjacent to the upstream side, the process proceeds to step S53. In step S53, since it is determined that the destination of the monitoring request is other than itself, the process proceeds to step S55, and the operation is started in the operation mode unique to the relay communication device.

  FIG. 10 is a flowchart of the “relay mode” executed by the relay communication device 5 (6). In step S200, the relay communication device 6 adjacent to the downstream side is determined based on the route table created at the time of route establishment. Explored. In step S <b> 201, a monitoring request destined for the receiving communication device 7 is transmitted to the relay communication device 6.

  In step S202, it is determined whether or not a response to the monitoring request is returned from the downstream relay communication device 6. If a monitoring response (ACK) is returned, the process proceeds to step S203. On the other hand, if the monitoring response is not returned within the predetermined time, there is a possibility that a failure has occurred on the downstream side of the route, and the process proceeds to step S208.

  In step S203, the monitoring signal interval calculation unit 103 calculates the monitoring period ΔT. At this time, in the relay communication device 5, the first monitoring period ΔT1 is calculated based on the monitoring sensitivity of the communication service provided on the route R1, and the second value is determined based on the monitoring sensitivity of the communication service provided on the route R2. A monitoring period ΔT2 is calculated.

  In step S204, the first monitoring cycle ΔT1 is notified to the transmitting communication device 3, and the second monitoring cycle ΔT4 is notified to the transmitting communication device 2. Therefore, thereafter, the monitoring signal St is transmitted from the transmission side communication devices 3 (4) at the monitoring periods ΔT1 and ΔT2, respectively.

  On the other hand, in the communication device 6, in step S203, the communication service provided by the route R1 and the communication service provided by the route R2 are referred to, and the third communication service is based on the communication service having the highest monitoring sensitivity. A monitoring period ΔT3 is calculated. In step S204, the third monitoring period ΔT3 is notified to the communication device 5. Therefore, thereafter, the monitoring signal St is transmitted from the upstream relay communication device 5 at the monitoring period ΔT3.

  In step S205, the monitoring period ΔT notified from the downstream communication device in response to the monitoring request is received. In step S206, the monitoring signal St is generated and transmitted in this monitoring cycle ΔT.

  Returning to FIG. 8, when the monitoring request transmitted from the relay communication device 6 is detected in step S51, the reception side communication device 7 (8) detects the communication whose request source is adjacent to the upstream side in step S52. Since it is determined to be an apparatus, the process proceeds to step S53. In step S53, since the destination of the monitoring request is determined to be itself, the process proceeds to step S56, and the operation is started in an operation mode unique to the receiving communication apparatus.

  FIG. 11 is a flowchart of the “reception side mode” executed by the reception side communication device 7 (8). In step S301, the monitoring signal interval calculation unit 103 calculates the monitoring period ΔT4 (ΔT5). In step S302, the monitoring cycle ΔT4 (ΔT5) is notified to the relay communication device 6. Therefore, thereafter, the monitoring signal St is transmitted from the upstream relay communication device 6 to the receiving communication device 7 at the monitoring cycle ΔT4, and the monitoring signal St is transmitted to the receiving communication device 8 at the monitoring cycle ΔT5. It will be.

  In step S303, it is determined whether or not the monitoring signal St transmitted from the upstream relay communication device 6 is correctly received in the monitoring cycle ΔT4 (ΔT5). If the reception cycle of the monitoring signal St is substantially the monitoring cycle ΔT4 (ΔT5), the process returns to step S301 and the above nuclear processing is repeated. On the other hand, if it is determined that the monitoring signal St is not correctly received in the monitoring period ΔT, the process proceeds to step S304. In step S304, a failure occurrence notification is transmitted to the upstream relay communication device 6, and in step S305, a failure handling process registered in advance is appropriately executed.

  In this embodiment, an asymmetric path failure is assumed in which the uplink failure and the downlink failure are independent, so even if a failure occurs in the downlink as described above, the uplink route A route failure can be notified to the upstream communication device. Even if a symmetric failure occurs, if the cause is temporary or sporadic, such as an increase in buffer delay, the upstream communication device is sent to the upstream communication device at the timing when the failure does not occur. A route failure can be notified.

  Returning to FIG. 10, in the relay communication device 5 (6), in step S207, it is determined whether or not the monitoring signal St transmitted from the upstream communication device is correctly received in the monitoring cycle ΔT. If the reception cycle of the monitoring signal St is not substantially the monitoring cycle ΔT, the process proceeds to step S208, and a failure occurrence notification is transmitted to the upstream communication device.

  On the other hand, if the reception cycle of the monitoring signal St is substantially the monitoring cycle ΔT, the process proceeds to step S209, and it is determined whether a failure occurrence notification is received from the downstream communication device. If it has been received, the process proceeds to step S210, and the failure notification is transferred to the upstream communication device.

  Returning to FIG. 9, in step S <b> 105, the transmission side communication device 3 (4) determines whether or not a failure occurrence notification is received from the downstream side communication device. If it has been received, the process proceeds to step S106, and a unique handling process is appropriately executed when a failure occurs.

  In each of the above-described embodiments, the upstream communication apparatus has been described as detecting a failure in a downlink or a route by periodically receiving a failure occurrence notification notified from the downstream communication apparatus. However, the present invention is not limited to this, and the downstream communication device returns a monitoring response St_ack in response to reception of the monitoring signal St, and the upstream communication device transmits the monitoring signal St. Thereafter, when a monitoring response St_ack cannot be received within a predetermined period, a failure in the downstream path may be detected.

  At this time, if the relay communication device 5 (6) cannot receive the monitoring response St_ack from the downstream communication device, even if the monitoring signal St can be normally received from the upstream communication device, By not sending back the monitoring response St_ack, it becomes possible to sequentially notify the path failure to the upstream communication device.

  DESCRIPTION OF SYMBOLS 1-8 ... Communication apparatus, 101 ... Communication service part, 102 ... User data formation part, 103 ... Monitoring signal interval calculation part, 104 ... Data buffer and monitoring signal multiplexing part, 105 ... Signal transmission part, 106 ... Signal reception part , 107 ... Monitoring signal generation unit, 108 ... Monitoring request data decoding unit, 109 ... Data / monitoring signal separation unit, 110 ... Line alive determination unit, 111 ... Line failure handling unit, 112 ... User data restoration unit

Claims (10)

In the line monitoring method for determining the life and death of the monitoring line connecting the communication device on the transmission side and the communication device on the reception side,
An identification means for identifying the communication service provided by the monitoring line;
Monitoring period calculation means for calculating a monitoring period based on the identification result;
Monitoring signal request means for transmitting a monitoring signal request including the monitoring cycle from the receiving side to the transmitting side communication device;
Monitoring signal transmitting means for transmitting a monitoring signal at the monitoring period from the transmitting side to the receiving side communication device;
A line monitoring system comprising life / non-life determination means for determining whether the monitoring line is active or not based on whether the monitoring signal or a monitoring response returned to the monitoring signal is normally received.   2. The life / death determination means determines whether a monitoring line is alive based on whether or not the monitoring signal is received in a cycle corresponding to the monitoring cycle in a communication device on the receiving side. The line monitoring method described.   2. The line according to claim 1, wherein the life / non-life determining unit determines whether the monitoring line is alive based on whether a monitoring response is received with respect to the monitoring signal in the communication device on the transmission side. Monitoring method.   4. The line according to claim 1, wherein the monitoring period calculation means calculates the monitoring period so that a monitoring period of a monitoring line that provides a communication service with higher real-time characteristics becomes shorter. Monitoring method.   5. The line monitoring system according to claim 4, wherein the monitoring cycle calculating means calculates a monitoring cycle based on a communication service having the highest real-time property when a plurality of communication services are provided on the monitoring line. .   6. The line according to claim 1, further comprising monitoring signal superimposing means for superimposing the monitoring signal on a signal transmitted to a receiving-side communication device at a timing corresponding to the monitoring cycle. Monitoring method. In a network including a plurality of communication devices, in a line monitoring method for determining whether a monitoring line connecting a communication device on a transmission side and a communication device on a reception side is active or not,
The communication device on the receiving side
A procedure for identifying a communication service provided by a monitoring line set up with a communication device on the transmission side;
A procedure for calculating a monitoring period based on the identification result;
Transmitting a monitoring signal request including the monitoring cycle to a communication device on the transmission side,
The transmitting communication device is
Receiving a monitoring signal request describing the monitoring period;
A procedure for transmitting a monitoring signal to the communication device on the receiving side in the monitoring cycle,
A line monitoring method characterized by determining whether a monitoring line is active or not based on whether the monitoring signal or a monitoring response returned to the monitoring signal is normally received.   8. The line monitoring method according to claim 7, wherein in the procedure of calculating the monitoring period, the monitoring period is calculated so that the monitoring period of the monitoring line that provides a communication service with higher real-time property is shorter. .   9. The procedure according to claim 8, wherein in the procedure for calculating the monitoring period, when a plurality of communication services are provided on the monitoring line, the monitoring period is calculated based on the communication service having the highest real-time property. Line monitoring method. A relay communication device that relays communication between the transmission side and the reception side.
A procedure for identifying a communication service provided by a monitoring line set up with a communication device on the transmission side;
A procedure for calculating a monitoring cycle on the transmission side based on the identification result;
A procedure for transmitting a monitoring signal request including the monitoring cycle on the transmission side to the communication device on the transmission side;
A procedure for receiving a monitoring signal request describing a monitoring cycle on the receiving side from a communication device on the receiving side;
The line monitoring method according to claim 7, further comprising a procedure of transmitting a monitoring signal to the receiving-side communication device at the monitoring period on the receiving side.