JP2012199641A - System, method and program for monitoring terminal device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a terminal device monitoring system capable of protecting a TRAP packet from a loss caused by a deteriorated channel quality only by treatment on the terminal device side, as a monitoring network using TRAP packets of SNMP communication.SOLUTION: In a system including two monitoring servers for monitoring the states of devices N1-N8 channel-connected in turn from an uplink direction to a downlink direction, in which a server A1 is disposed in the uplink direction while a server A2 is disposed in the downlink direction, and a TRAP packet is transmitted to both servers A1, A2 when a state changes in each device N1-N8, when for example, the device N3 detects quality deterioration of a radio channel WL34 between the devices N3 and N4, a channel deterioration notification packet indicative of that effect is transmitted to the devices N2, N1 which are located in the opposite direction to the radio channel WL34. Similar to the device N3, the devices N2, N1 suspend the transmission operation of the TRAP packet directed to the server A2 on a route passing through the radio channel WL34, and also perform operation to preserve a TRAP packet which occurs thereafter.

Description

  The present invention relates to a terminal device monitoring system, a terminal device monitoring method, and a terminal device monitoring program. In particular, the present invention relates to a terminal device monitoring system, a terminal device monitoring method, and a terminal device monitoring program when a TRAP packet (trap packet) of SNMP (Simple Network Management Protocol) communication is used to monitor the status of a terminal device having a wireless access function. .

  A TRAP packet (trap packet) in IP (Internet protocol) -based SNMP communication is a packet for status change notification sent from the SNMP agent of the terminal device to the SNMP manager of the monitoring server. In order to be able to detect the reception loss of the TRAP packet on the monitoring server side, Japanese Patent Application Laid-Open No. 2008-97326 “SNMP Sequence Management Method, Manager Device and Agent Device” of Patent Document 1 No.-244142, “Trap Loss Detection Method and Detection Method in IP Network”, etc., proposes a technique for adding a TRAP Sequence ID to a TRAP packet as a sequence number indicating the transmission order.

  Also, in Japanese Patent Application Laid-Open No. 2008-198041 of “Patent Document 3”, “Device monitoring network system and SNMP trap management method”, a TRAP group is created based on a threshold for the number of TRAP packets transmitted per unit time. A retransmission method of TRAP packets by continuity check is proposed.

JP 2008-97326 A (page 6-8) Japanese Patent Laying-Open No. 2003-244142 (page 5-7) JP 2008-198041 A (page 6-8)

  However, in the case of the method of adding a TRAP Sequence ID as proposed in Patent Document 1, Patent Document 2, etc., the server side detects that a gap has occurred in receiving a TRAP packet from the terminal device. Therefore, it is necessary to make a retransmission request for the missing TRAP packet to the terminal device, and it is necessary to change the monitoring system on the server side. Further, when the line quality is deteriorated between the server and the terminal device, retransmission due to the drop of the TRAP packet by the line is frequently performed between the server and the terminal device. There was a problem that the load increased on both sides.

  Further, in the case of the TRAP packet retransmission method based on the threshold for the number of TRAP packets transmitted as described in Patent Document 3, as a countermeasure against TRAP packets when a network failure or the like occurs in the middle of the circuit path, NMS ( It is necessary to confirm from the (Network Management System) side.

(Object of the present invention)
The present invention has been made in view of such circumstances, and as a monitoring network that uses a TRAP packet of SNMP communication to monitor a terminal device, it is possible to monitor without changing the configuration / function of a server serving as a monitoring device. It is an object of the present invention to provide a terminal device monitoring system, a terminal device monitoring method, and a terminal device monitoring program that can prevent the loss of TRAP packets due to line degradation only by changing the system in the terminal device on the device side. .

  In order to solve the above-described problems, the terminal device monitoring system, the terminal device monitoring method, and the terminal device monitoring program according to the present invention mainly adopt the following characteristic configuration.

  (1) A terminal device monitoring system according to the present invention includes two monitoring servers that monitor the status of each of one or more terminal devices connected in a line in order from an upstream direction to a downstream direction. The terminal device is connected to the terminal device at the head of the direction, and the other monitoring server is connected to the terminal device at the tail of the downstream direction. Each of the terminal devices has a status in the terminal device. Terminal that transmits a TRAP packet (trap packet) for status change notification compliant with the Simple Network Management Protocol (SNMP) standard to both of the two monitoring servers located in the upstream and downstream directions when a change occurs In the device monitoring system, when the terminal device detects deterioration in the quality of the line connecting the terminal device and the adjacent terminal device, the deterioration detection is performed. As an intelligent device, the line is stored as a quality degradation point, the transmission operation of the TRAP packet in the direction of the quality degradation line that has become the quality degradation point is stopped, and a status change notification that occurs thereafter Performing the operation of storing the TRAP packet and creating a line deterioration notification packet indicating that quality deterioration has occurred in the quality deteriorated line, all the positions located in the opposite direction to the quality deteriorated line The terminal device that transmits to the wireless device and receives the line deterioration notification packet from the deterioration detecting device stores the quality deteriorated line as a quality deteriorated portion and heads for a route passing through the quality deteriorated line The TRAP packet transmission operation is stopped, and the operation for storing the TRAP packet for status change notification that occurs thereafter is performed.

  (2) The terminal device monitoring method according to the present invention comprises two monitoring servers that monitor the status of each of one or more terminal devices connected in order from the upstream direction to the downstream direction. The terminal device is connected to the terminal device at the head of the direction, and the other monitoring server is connected to the terminal device at the tail of the downstream direction. Each of the terminal devices has a status in the terminal device. Terminal that transmits a TRAP packet (trap packet) for status change notification compliant with the Simple Network Management Protocol (SNMP) standard to both of the two monitoring servers located in the upstream and downstream directions when a change occurs A device monitoring method, wherein when the terminal device detects deterioration in quality of a line connecting the terminal device and an adjacent terminal device, the deterioration detection device The line is stored as a quality degradation location, the transmission operation of the TRAP packet in the direction of the quality degradation channel that has become the quality degradation location is stopped, and the status change notification that occurs thereafter Performs an operation of storing a TRAP packet and creates a line deterioration notification packet indicating that quality deterioration has occurred in the quality deteriorated line, and all the radios located in the opposite direction to the quality deteriorated line The terminal device that has transmitted to the device and received the line deterioration notification packet from the deterioration detecting device stores the quality deteriorated line as a quality deteriorated portion and travels to the route passing through the quality deteriorated line The packet transmission operation is stopped, and the operation for storing the TRAP packet for status change notification that occurs thereafter is performed.

  (3) A terminal device monitoring program according to the present invention is characterized in that at least the terminal device monitoring method described in (2) is implemented as a program executable by a computer.

  According to the terminal device monitoring system, the terminal device monitoring method, and the terminal device monitoring program of the present invention, the following effects can be obtained.

  As a first effect, in the server of the monitoring device, it is not necessary to be aware of the line quality deterioration state in each terminal device which is the monitoring target device, and any line in each terminal device has quality deterioration. Even if it occurs, the transmission operation of the TRAP packet of the route through the line where the quality degradation has occurred can be surely stopped on each terminal device side without any server involvement, and the TRAP packet can be transmitted from each terminal device. It is possible to prevent the reception loss of the information related to the status change transmitted by.

  As a second effect, in the server of the monitoring device, information indicating a change in situation while the transmission operation of the TRAP packet was stopped on each terminal device side of the monitoring target device without changing the reception method of the TRAP packet. When the channel quality is restored and the line quality is restored, the TRAP packet retransmission operation on each terminal device side is automatically activated to receive the TRAP packet for status change notification saved during the suspension period. It is possible to supplement the information on the status change of each terminal device.

It is a system configuration figure showing an example of a system configuration of a terminal unit monitoring system by the present invention. It is a table for demonstrating an example of the information set to the variable designation | designated part (Variable Bindings) which comprises a part of SNMP TRAP packet. 3 is a table for explaining an example of a format of a line deterioration notification packet and a line recovery notification packet that are notified to other devices by each device of the terminal device monitoring system shown in FIG. 1. It is explanatory drawing explaining an example of the notification direction of the channel degradation notification packet when the channel quality of the radio channel between the apparatuses of the terminal device monitoring system of FIG. 1 deteriorates. It is explanatory drawing explaining an example of the notification direction of the line | wire recovery notification packet when the line quality which the wireless line between the apparatuses of the terminal device monitoring system of FIG. 1 deteriorated recovered. 3 is a table for explaining an example of a format of a line confirmation packet that each device of the terminal device monitoring system shown in FIG. 1 periodically transfers to an adjacent device. It is explanatory drawing explaining an example of the transmission / reception operation | movement of the packet for a line confirmation which confirms the line quality of the wireless line between the apparatuses of the terminal device monitoring system of FIG. It is explanatory drawing explaining the other example of the transmission / reception operation | movement of the packet for a line confirmation which confirms the line quality of the wireless line between the apparatuses of the terminal device monitoring system of FIG. It is explanatory drawing explaining a mode that the notification of a line degradation notification packet is divided | segmented when the line quality of the some radio | wireless line between the apparatuses of the terminal device monitoring system of FIG. 1 deteriorates. It is explanatory drawing explaining a mode that the notification of the line recovery notification packet transmitted when the channel quality which the radio | wireless line between the apparatuses of the terminal device monitoring system of FIG. It is a flowchart for demonstrating an example of the operation | movement at the normal time in each apparatus of the terminal device monitoring system of FIG. 3 is a flowchart for explaining an example of a transmission operation of a line deterioration notification packet and a line restoration notification packet in each device of the terminal device monitoring system of FIG. 1. 6 is a flowchart for explaining an example of an operation when receiving a line degradation notification packet in each device of the terminal device monitoring system of FIG. 1. 6 is a flowchart for explaining an example of an operation when receiving a line restoration notification packet in each device of the terminal device monitoring system of FIG. 1. 3 is a flowchart for explaining an example of an operation at the time of transmission / reception of a line confirmation packet in each device of the terminal device monitoring system of FIG. 1.

  Preferred embodiments of a terminal device monitoring system, a terminal device monitoring method, and a terminal device monitoring program according to the present invention will be described below with reference to the accompanying drawings. In the following description, the terminal device monitoring system and the terminal device monitoring method according to the present invention will be described. However, the terminal device monitoring method may be implemented as a terminal device monitoring program that can be executed by a computer. Alternatively, it goes without saying that the terminal device monitoring program may be recorded on a computer-readable recording medium.

(Features of the present invention)
Prior to the description of the embodiments of the present invention, an outline of the features of the present invention will be described first. The present invention relates to a TRAP packet (trap packet: an SNMP agent of a terminal device to a monitoring server) for monitoring the status of a terminal device (hereinafter also simply referred to as “device”). The present invention relates to a monitoring network using a status change notification packet sent to an SNMP manager. Each terminal device observes the line quality state in the line (wireless line, wired line) with the opposite device (terminal device or monitoring server) on the other side of the SNMP communication, and whether or not the line quality has deteriorated. Is monitoring. When the degradation of the line quality is detected, the terminal apparatus stops transmission of the TRAP packet in the direction of the line where the degradation of the line quality has occurred, and other terminals connected in the opposite direction to the line A line deterioration notification packet indicating the line quality deterioration of the line is transmitted to the terminal device.

  Each terminal device that has received the line degradation notification packet stops the transmission processing of the TRAP packet of the route passing through the line with degraded line quality, and stores the TRAP packet after the occurrence of the line quality degradation as an untransmitted TRAP packet. To do. By performing this operation, it is possible to prevent the loss of TRAP packets due to line quality degradation by changing the system in the terminal device on the monitored device side without changing the configuration / function on the existing monitoring server side. ing.

  Furthermore, when the radio status of a radio channel with degraded channel quality is restored to normal, the channel quality is restored to each terminal device that has transmitted a channel degradation notification packet indicating the degradation of the channel quality. A line restoration notification packet indicating that it has been sent is transmitted. In each terminal device that has received the line restoration notification packet, the monitoring server restarts the transmission operation of the TRAP packet, including the TRAP packet that has been saved by stopping transmission to the route passing through the line. Makes it possible to supplement information relating to the status change of each terminal device during the unmonitorable time due to line quality degradation.

(Configuration example of embodiment)
Next, as an embodiment of the present invention, a system configuration example of a terminal device monitoring system according to the present invention will be described with reference to FIG. FIG. 1 is a system configuration diagram showing an example of a system configuration of a terminal device monitoring system according to the present invention. The terminal device monitoring system shown in FIG. 1 has eight terminal devices N1, N2,..., N8 connected in cascade as terminal devices to be monitored, and these eight devices N1, N2 ,..., N8, a case where two monitoring servers, a server A1 and a server A2, are provided. However, in the terminal device monitoring system according to the present invention, the number of terminal devices to be monitored is not limited to eight as illustrated in FIG. 1 and may be any number.

  As for the network configuration of the terminal device monitoring system in FIG. 1, between each of device N1-device N2, device N3-device N4, device N5-device N6, device N7-device N8, which are terminal devices to be monitored, IP (Internet Protocol) communication is performed by each of the wireless line WL12, the wireless line WL34, the wireless line WL56, and the wireless line WL78, and between the devices N2-device N3, device N4-device N5, device N6-device N7, respectively. It is assumed that IP communication is performed through the wired line W23, the wired line W45, and the wired line W67. The server A1 of the monitoring server performs IP communication with the device N1 arranged at the head in the upstream direction through the wired line W11, and the server A2 as the other monitoring server is connected to the server A1 side. It is assumed that IP communication is performed via a wired line W82 with a device N8 that is on the opposite side to the device N1 and is arranged at the tail end in the downstream direction.

  The servers A1 and A2 of the monitoring server are implemented with an IP-based SNMP protocol as an SNMP manager, and the eight devices N1, N2,..., N8 to be monitored via the wired lines W11 and W82, respectively. IP-based SNMP communication is performed. On the other hand, each of the devices N1, N2,..., N8, which is a terminal device to be monitored, is connected to two lines, a wired line and a wireless line. It is possible to perform IP-based SNMP communication in two directions.

  Each of the devices N1, N2,..., N8 is an SNMP agent when a change in the status of its own device such as an update of stored information or an occurrence of some event occurs. An IP-based SNMP protocol for transmitting a status change notification indicating that to the servers A1 and A2 of the monitoring server is implemented, and the status change notification is used by using a TRAP packet (trap packet) in SNMP communication. To send.

  Therefore, each of the devices N1, N2,..., N8 recognizes from which direction of the wired line or the wireless line it has received the SNMP communication TRAP packet and to which direction the TRAP packet should be transmitted. It is possible to do it.

  Further, as shown in FIG. 1, each of the devices N1, N2,..., N8 includes a TRAP destination address / direction / degradation notification source table 10i, a transmitted TRAP Sequence ID management table 20i, and a transmission TRAP table 30i. . Here, i added to the reference numeral is an integer of 1 to 8, and is a variable corresponding to the device numbers of the devices N1, N2,. For example, the device N1 includes a TRAP destination address / direction / degradation notification source table 101, a transmitted TRAP Sequence ID management table 201, and a transmission TRAP table 301. In the case of the device N2, the TRAP destination address / direction / direction / A degradation notification source table 102, a transmitted TRAP Sequence ID management table 202, and a transmission TRAP table 302 are provided.

  The first TRAP transmission destination address / direction / deterioration notification source table 10i is a table for setting the transmission destination of the TRAP packet, the transmission direction, and the notification source of the line deterioration notification. The transmission destination IP address 11i, the direction 12i , And at least the deterioration notification source device 13i. The IP address of each of the servers A1 and A2 of the monitoring server that is the transmission destination of the TRAP packet is set as the transmission destination IP address 11i. In the direction 12i, the line type of the line connected to the port in the transmission direction of the TRAP packet for transmitting the TRAP packet to the servers A1 and A2 is set. In the case of the setting example shown in FIG. 1, the line type in the transmission direction for the upstream server A1 is a wireless line, and the line type in the transmission direction for the downstream server A2 is a wired line. In the degradation notification source device 13i, a device number that uniquely identifies the notification source device that has transmitted the degradation notification of the line quality is set.

  In this embodiment, in order to simplify the description, it is assumed that the line type in which the line quality deteriorates in the network is not a wired line but a wireless line in which the radio wave state etc. changes. However, this is not the only case. In other words, when the case where quality degradation or the like occurs in a wired line is also targeted, in addition to the degradation notification source device 13i, a line type indicating whether the line quality degradation has occurred in either a wireless line or a wired line What is necessary is just to set it together.

  With this TRAP destination address / direction / deterioration notification source table 10i, each SNMP agent of the device Ni (i = 1 to 8) transmits from its own device Ni to each of the SNMP managers of the servers A1 and A2 of the monitoring server. It is possible to recognize in which direction the TRAP packet should be transmitted, and in which of the eight terminal devices the line quality degradation, for example, the quality degradation of the radio line is occurring. is there.

  The second transmitted TRAP Sequence ID management table 20i is stored in the monitoring server via the route passing from the own device Ni through the route immediately before the degradation of the channel quality occurs in the channel used by any of the devices N1 to N8. It is a table for setting a TRAP Sequence ID for uniquely identifying the final TRAP packet transmitted to each of the servers A1 and A2, and includes at least a transmission destination IP address 21i and a TRAP Sequence ID 22i. The IP address of each of the servers A1 and A2 of the monitoring server that is the transmission destination of the TRAP packet is set as the transmission destination IP address 21i. In the TRAP Sequence ID 22i, a sequence number for uniquely specifying the last TRAP packet transmitted immediately before the time among the transmitted TRAP packets transmitted until the time when the line quality deteriorates is set. In the display example of FIG. 1, “3” is set in the TRAP Sequence ID 22i, and it is illustrated that the TRAP packet having the TRAP Sequence ID “3” has been transmitted to both the servers A1 and A2. is doing.

  By this TRAP Sequence ID management table 20i, it is possible to manage the TRAP packets that have been transmitted from the own apparatus Ni to the servers A1 and A2 by the time when the line quality of the apparatus N1 to N8 has deteriorated. become.

  The third transmission TRAP table 30i is a table for sequentially storing TRAP packets transmitted from the own apparatus Ni for notification of the status change when a status change occurs in the apparatus Ni (i = 1 to 8). And includes at least a TRAP Sequence ID 31i, a time 32i, and a TRAP content 33i. In the TRAP Sequence ID 31i, a sequence number for uniquely identifying the transmitted TRAP packet is set. The transmission time at which the TRAP packet is transmitted is set as the time 32i. In the TRAP content 33i, the content of the TRAP packet for status change notification is set.

  In this transmission TRAP table 30i, not only the latest transmission TRAP packet in which a change in situation has occurred but also transmission TRAP packets transmitted in the past are stored as history information, so among the TRAP packets transmitted so far, It becomes possible to retransmit a TRAP packet corresponding to an arbitrary TRAP Sequence ID later.

  Next, an example of the format of the status change notification TRAP packet will be described. Each of the devices N1, N2,..., N8 uses the SNMP protocol TRAP packet to the monitoring servers A1 and A2 when the status of the device changes, as described above. To be notified. At this time, the servers A1 and A2 that have received the TRAP packet for notifying the situation change not only the contents of the situation change that occurred in each of the devices N1, N2,. In order to be able to recognize the missing TRAP packet, information as illustrated in FIG. 2 is transmitted to the variable designation part (Variable Bindings) of the TRAP packet in the TRAP packet transmitted from the devices N1, N2,. include.

  FIG. 2 is a table for explaining an example of information to be set in a variable designation unit (Variable Bindings) constituting a part of the SNMP TRAP packet, and is transmitted from the devices N1, N2,..., N8 as described above. Information indicating the order of the TRAP packets, the date and time of occurrence of the situation change, and the notification contents of the situation change are included.

  That is, as shown in the format of the TRAP packet in FIG. 2, the variable designation part (Variable Bindings) of the TRAP packet is composed of a plurality of fields. The VBL1 field in FIG. 2 is a field for setting a TRAP Sequence ID indicating the order of transmission TRAP packets, and the sequence number of the TRAP packet is set. The VBL2 field is a field for setting a change occurrence date and time indicating the occurrence date and time of the situation change, and time information is set in the format of YYYY / MM / DD HH: MM: SS. Further, the VBL3 field, the VBL4 field,... Are fields for setting change notification contents 1, change notification contents 2,.

  Next, when the deterioration of the line quality of the wireless line and the wired line used by the devices N1, N2,..., N8 is detected, on the contrary, the operation when the line quality is restored to the normal state is detected. A case will be described as an example where the line quality of a wireless line changes as the line type. Each of the devices N1, N2,..., N8 measures the received electric field level of the radio signal in the radio channel unit in order to monitor the change in channel quality of the radio channel used by the own device. However, when the electric field level for detecting the deterioration of the line quality is lower than a predetermined line deterioration electric field threshold, it is detected that the quality deterioration of the wireless line has occurred.

  In the device Ni (i = 1 to 8) that has detected the deterioration of the quality of the wireless line, the use of the wireless line in which the quality deterioration has occurred is stopped, and a line deterioration notification packet indicating the fact is created using the IP packet. Then, other devices Nj (j = 1 to 8 and j ≠ i) are notified.

  On the other hand, a line that has been determined in advance as an electric field level for detecting that the line quality of a wireless line that has been discontinued due to degraded line quality has recovered and the received electric field level has recovered to a normal state. When the recovery electric field threshold is reached or higher, in the apparatus Ni (i = 1 to 8) that detects the recovery of the quality of the wireless line, the use of the wireless line whose line quality is restored to the normal state is resumed. A line restoration notification packet indicating that fact is created using the IP packet and notified to other apparatuses Nj (j = 1 to 8 and j ≠ i).

  FIG. 3 shows a line degradation notification packet that each device Ni (i = 1 to 8) of the terminal device monitoring system shown in FIG. 1 notifies other devices Nj (j = 1 to 8 and j ≠ i). 4 is a table for explaining an example of a format of a line recovery notification packet. As shown in FIG. 3, both the line degradation notification packet and the line restoration notification packet are configured to include at least a destination address 41, a transmission source address 42, and a data unit 43. In the destination address 41, an IP address of a device that is a destination for transmitting the packet is set. In the transmission source address 42, the IP address of the transmission source device of the packet is set. The data unit 43 is a part for setting notification contents, and includes at least fields of a notification type 43a indicating one of a line deterioration notification and a line restoration notification, and a notification time 43b indicating the time when the packet is transmitted. It is configured.

  As shown in the destination address 41 of FIG. 3, the destination address 41 includes all the devices Nj other than the source device Ni (i = 1 to 8) in both the line degradation notification packet and the line restoration notification packet. “Broadcast Address” (broadcast address) indicating that transmission is performed in a broadcast format is set for (j = 1 to 8 and j ≠ i), and all devices Nj (j = 1 to 1) are set. 8 and j ≠ i), the fact that the line quality has deteriorated or the line quality has been recovered is notified all at once.

  Further, as shown in the notification type 43a of the data section 43 in FIG. 3, the notification of the change in the line quality detected in the device Ni (i = 1 to 8) indicated by the transmission source address 42 The flag “1” or “0” sets whether the notification is a line deterioration notification indicating quality deterioration or a line restoration notification indicating line quality recovery. However, each device Ni (i = 1 to 8) is provided with two lines, a wired line and a wireless line, as shown in FIG. 1, but in this embodiment, as described above. The case where the line whose line quality changes is a wireless line is shown as an example. In the case of notification including a wired line, in addition to the line quality change type, the line type in which the line quality change may occur may be set.

  Further, as shown in the notification time 43b of the data unit 43 in FIG. 3, the time when the change in the line quality (that is, the deterioration of the line quality or the recovery of the line quality) is detected is represented by YYYY / MM / DD HH: MM: SS. Notification is made using a format of “year / month / day hour: minute: second”.

  By transmitting the line degradation notification packet and the line restoration notification packet as shown in FIG. 3 from the device Ni (i = 1 to 8) that has detected the change in the line quality, the line degradation notification packet and the line restoration notice packet are transmitted. In each of the other devices Nj (j = 1 to 8 and j ≠ i) receiving the signal, the occurrence location of the change in the line quality, the type of the change in the line quality, and the occurrence time of the change in the line quality are recognized. It becomes possible to do.

  Next, as an example of the operation when a change in the line quality occurs in the wireless line used by the terminal device to be monitored, the case where the line quality deteriorates in the wireless line WL34 between the devices N3 and N4, The notification direction of the line deterioration notification packet will be specifically described with reference to FIG. FIG. 4 is an explanatory diagram illustrating an example of a notification direction of a line deterioration notification packet when the line quality of the wireless line between the apparatuses of the terminal apparatus monitoring system of FIG. 1 is deteriorated. The case where the line quality deteriorates in the wireless line WL34 is shown as an example.

  In each of the devices N3 and N4 in FIG. 4, the electric field level for measuring the reception electric field level in the wireless communication unit of the wireless line WL34 between the device N3 and the device N4 to determine whether or not the line quality is deteriorated. It is monitored whether it has fallen below a predetermined line degradation electric field threshold value. When the device N3 and the device N4 respectively detect that the measured received electric field level is lower than the line deterioration electric field threshold value, the devices N3 and N4 respectively connect the wireless line WL34 between the devices N3 and N4. It is determined that the quality has deteriorated.

  Each of the device N3 and the device N4 stops using the wireless line WL34 based on the determination result of the deterioration of the line quality of the wireless line WL34, and shows that the line quality of the wireless line WL34 has deteriorated. The line degradation notification packet as shown above is generated, and the operation of transmitting the broadcast format from the devices N3 and N4 to the other devices N1, N2, N5, N6, N7, and N8 is started.

  Here, as shown in FIG. 4, each of the devices N3 and N4 performs an operation of transmitting a channel degradation notification packet in the opposite direction to the radio channel WL34 whose channel quality is degraded. That is, the device N3 located in the upstream direction of the wireless line WL34 transmits a line degradation notification packet to the devices N1 and N2 existing in the upstream direction opposite to the wireless line WL34 whose channel quality is degraded. On the other hand, the device N4 located in the downstream direction of the wireless line WL34 is connected to the devices N5, N6, N7, and N8 that exist in the downstream direction opposite to the wireless line WL34 whose channel quality has deteriorated. In response, a line degradation notification packet is transmitted.

  As a result, for example, in the device N2 located in the upstream direction of the device N3 that is the transmission source of the line deterioration notification packet, the line deterioration notification packet is received from the normal direction of the wired line W23 (that is, the downward direction) The device N1 located in the upstream direction of the device N3 that is the transmission source of the line deterioration notification packet also receives the line deterioration notification packet from the normal wireless line WL12 direction (that is, the downlink direction). Therefore, it is possible to reliably recognize that the line quality has deteriorated in the wireless line WL34 of the device N3.

  Thus, each of the devices N1, N2, and N3, including the device N3 that has detected the deterioration of the line quality of the wireless line WL34, is notified of the deterioration of the TRAP destination address / direction / deterioration notification source tables 101, 102, and 103. In the original apparatuses 131, 132, and 133, the fact that the line quality has deteriorated is set for the wireless line WL34 of the apparatus N3 existing in the communication route toward the server A2 in the downstream direction.

  Therefore, in the devices N1, N2, and N3 that refer to the degradation notification source devices 131, 132, and 133 in the TRAP transmission destination address / direction / degradation notification source tables 101, 102, and 103, respectively, the statuses are changed from the devices N1, N2, and N3, respectively. The operation of transmitting the change notification TRAP packet to the downstream server A2 is stopped, and is transmitted only to the upstream server A1.

  Further, in each of the devices N1, N2, and N3, the notification time set at the notification time 43b of the data portion 43 of the line deterioration notification packet (the time when deterioration of the line quality of the wireless line WL34 is detected) and the transmission TRAP The transmission times of the transmission TRAP packets set in the times 321, 322, and 323 of the tables 301, 302, and 303 are compared with each other. Based on the comparison result, it is determined that the TRAP packet for the downstream server A2 transmitted at a time after the time set as the notification time 43b cannot be notified to the server A2, and the notification time 43b It is determined that the server A2 can be notified of up to the TRAP packet for the server A2 transmitted at the time before the set time.

  Accordingly, each of the devices N1, N2, and N3 has received a line restoration notification packet indicating that the wireless line WL34 has been restored, and has failed to notify the server A2 when the transmission operation is resumed. In order to enable retransmission from the determined untransmitted TRAP packet to the server A2, the following process is performed to acquire and store the final TRAP Sequence ID of the successfully transmitted TRAP packet. . That is, in each of the devices N1, N2, and N3, the TRAP Sequence ID of the TRAP packet transmitted at the time immediately before the notification time set in the notification time 43b is used as the TRAP Sequence ID of the transmission TRAP tables 301, 302, and 303. Acquired from each of the IDs 311, 312, and 313, and set in the TRAP Sequence IDs 221, 222, and 223 for the server A2 in the transmitted TRAP Sequence ID management tables 201, 202, and 203, respectively.

  In addition, each of the devices N5, N6, N7, and N8 that have received the channel degradation notification packet from the device N4 that exists in the downstream direction of the wireless channel WL34 in which the channel quality is degraded includes the device N4 that has detected the degradation of the channel quality, The same operation is performed. In each of the devices N5, N6, N7, and N8, first, the degradation notification source devices 134, 135, 136, 137, and 138 of the respective TRAP destination address / direction / degradation notification source tables 104, 105, 106, 107, and 108 are used. In each case, the fact that the line quality has deteriorated is set in the wireless line WL34 of the device N4 existing in the communication route toward the upstream server A1.

  Therefore, the devices N4, N5, N6, N7, N8 referencing the degradation notification source devices 134, 135, 136, 137, 138 of the TRAP destination address / direction / degradation notification source tables 104, 105, 106, 107, 108, respectively. , The operation of transmitting the TRAP packet for status change notification from each of the devices N4, N5, N6, N7, and N8 to the upstream server A1 is stopped, and is transmitted only to the downstream server A2. become.

  Further, in each of the devices N4, N5, N6, N7, and N8, the notification time set at the notification time 43b of the data portion 43 of the line deterioration notification packet (the time when deterioration of the line quality of the wireless line WL34 is detected) And the transmission times of the transmission TRAP packets set in the times 324, 325, 326, 327, and 328 of the transmission TRAP tables 304, 305, 306, 307, and 308, respectively. Based on the comparison result, it is determined that the TRAP packet for the upstream server A1 transmitted at a time after the time set as the notification time 43b cannot be notified to the server A1, and the notification time 43b It is determined that the server A1 can be notified of up to the TRAP packet for the server A1 transmitted at a time before the set time.

  Accordingly, each of the devices N4, N5, N6, N7, and N8 receives the line restoration notification packet indicating that the wireless line WL34 has been restored and notifies the server A1 when the transmission operation is resumed. In order to enable retransmission to the server A1 from an untransmitted TRAP packet determined to have failed, the final TRAP Sequence ID of a successfully transmitted TRAP packet is acquired and stored as follows: Perform proper processing. That is, in each of the devices N4, N5, N6, N7, and N8, the TRAP Sequence ID of the TRAP packet that was transmitted at the time immediately before the notification time set in the notification time 43b is set to the transmission TRAP tables 304, 305, TRAP Sequence IDs 224, 225 for the server A1 of the TRAP Sequence ID management tables 204, 205, 206, 207, 208 that have been acquired from the TRAP Sequence IDs 314, 315, 316, 317, 318 of 306, 307, 308, respectively. 226, 227, and 228, respectively.

  As described above, for example, when the line quality deteriorates in the wireless line WL34, the TRAP packets for the servers A1 and A2 are transmitted from the devices N1 to N8 without receiving requests or instructions from the servers A1 and A2. As for the operation to be performed, the transmission operation of the TRAP packet in the direction in which the line deterioration notification packet is received, that is, the transmission operation of the TRAP packet of the route passing through the wireless line WL34 at the line deterioration point is stopped. Furthermore, the transmission TRAP packet transmitted after the time of occurrence of degradation of the line quality is stored. Therefore, it is possible to reliably prevent a TRAP packet reception loss in the servers A1 and A2.

  Next, each of the devices N1 to N8 confirms that the channel quality of the radio channel has recovered after the degradation of the channel quality of the radio channel, and restarts transmission of the TRAP packet that has been suspended. The operation will be described with reference to FIG. 5 by taking as an example a case where the line quality of the wireless line WL34 between the apparatus N3 and the apparatus N4 is recovered. FIG. 5 is an explanatory diagram for explaining an example of the notification direction of the line restoration notification packet when the line quality that has deteriorated the radio line between the apparatuses of the terminal apparatus monitoring system of FIG. The case where the deterioration of the line quality occurring in the wireless line WL34 between N4 is recovered is shown as an example.

  In each of the devices N3 and N4 in FIG. 5, the reception electric field level in the wireless communication unit of the wireless line WL34 between the devices N3 and N4 is measured. That the electric field level is lower than the predetermined line degradation electric field threshold, and that the electric field level for judging that the line quality has recovered to the normal state has reached the predetermined line restoration electric field threshold or more. Upon detection, each of the devices N3 and N4 determines that the degradation state of the channel quality of the radio channel WL34 between the devices N3 and N4 has been resolved and has been restored to normal channel quality.

  Each of the devices N3 and N4 restarts the use of the wireless line WL34 based on the determination result that the line quality of the wireless line WL34 has been recovered, and also indicates that the wireless line WL34 whose line quality has deteriorated has recovered. 3 is generated, and an operation for transmitting the data in the broadcast format from each of the devices N3 and N4 to the other devices N1, N2, N5, N6, N7, and N8 is started. The

  Here, as shown in FIG. 5, each of the devices N3 and N4 is connected in the same direction as the direction in which the line deterioration notification packet was transmitted, that is, in the opposite direction to the wireless line WL34 whose line quality has been restored. Send a recovery notification packet. That is, the device N3 located in the upstream direction of the wireless line WL34 transmits a line restoration notification packet to the devices N1 and N2 existing in the upstream direction opposite to the wireless line WL34 whose line quality has been recovered. On the other hand, the device N4 located in the downstream direction of the wireless line WL34 is connected to the devices N5, N6, N7, and N8 existing in the downstream direction opposite to the wireless line WL34 whose line quality has been recovered. In response to this, a line restoration notification packet is transmitted.

  As a result, for example, in the device N2 located in the upstream direction of the device N3 that is the transmission source of the line recovery notification packet, the line recovery notification packet is received from the normal direction of the wired line W23 (that is, the downward direction) The device N1 located in the upstream direction of the device N3 that is the transmission source of the line restoration notification packet also receives the line restoration notification packet from the normal wireless line WL12 direction (that is, the downlink direction). Therefore, it can be surely recognized that the line quality has been recovered in the wireless line WL34 of the device N3.

  Thus, each of the devices N1, N2, and N3, including the device N3 that has detected the recovery of the line quality of the wireless line WL34, is notified of the deterioration of the TRAP destination address / direction / deterioration notification source tables 101, 102, and 103. The setting indicating that the line quality of the wireless line WL34 of the device N3 existing in the communication route toward the server A2 in the downlink direction set in each of the original devices 131, 132, 133 is deleted, and the device N3 Switch to a state where the line quality of the wireless line WL34 is restored to a normal state.

  Therefore, in the devices N1, N2, and N3 that refer to the degradation notification source devices 131, 132, and 133 in the TRAP transmission destination address / direction / degradation notification source tables 101, 102, and 103, respectively, the statuses are changed from the devices N1, N2, and N3, respectively. The operation of transmitting the TRAP packet for change notification to the downstream server A2 is resumed, and is transmitted not only to the upstream server A1 but also to the downstream server A2.

  Further, in each of the devices N1, N2, and N3, in order to retransmit the TRAP packet for status change notification that has been transmitted after the deterioration of the channel quality of the radio channel WL34, the sequence ID management of the transmitted TRAP is performed. With reference to the TRAP Sequence IDs set in the TRAP Sequence IDs 221, 222, and 223 for the server A2 in the tables 201, 202, and 203, the TRAP Sequence of the final TRAP packet that has been normally transmitted to the server A2 Get an ID.

  Each of the devices N1, N2, and N3 uses the acquired TRAP Sequence ID to search the TRAP Sequence IDs 311, 312, and 313 in the transmission TRAP tables 301, 302, and 303, respectively, so that the TRAPs after the TRAP Sequence ID to be retransmitted The packet is extracted from each of the TRAP contents 331, 332, and 333, and retransmitted sequentially toward the downstream server A2.

  In addition, each of the devices N5, N6, N7, and N8 that received the line restoration notification packet from the device N4 existing in the downstream direction of the wireless line WL34 whose line quality has been recovered includes the device N4 that has detected the line quality recovery, The same operation is performed. In each of the devices N5, N6, N7, and N8, first, the degradation notification source devices 134, 135, 136, 137, and 138 of the respective TRAP destination address / direction / degradation notification source tables 104, 105, 106, 107, and 108 are used. The setting that the line quality of the wireless line WL34 of the device N4 existing in the communication route toward the server A1 in the upstream direction is deteriorated is deleted, and the line quality of the wireless line WL34 of the device N3 is deleted. Switch to the normal state.

  Therefore, the devices N4, N5, N6, N7, N8 referencing the degradation notification source devices 134, 135, 136, 137, 138 of the TRAP destination address / direction / degradation notification source tables 104, 105, 106, 107, 108, respectively. , The operation of transmitting the TRAP packet for status change notification from each of the devices N4, N5, N6, N7, and N8 to the upstream server A1 is resumed, and not only the downstream server A2 but also the upstream server It is also transmitted to the server A1.

  Further, in each of the devices N4, N5, N6, N7, and N8, the transmitted TRAP is transmitted in order to retransmit the TRAP packet for status change notification that is to be transmitted after the time when the channel quality of the wireless channel WL34 deteriorates. In the sequence ID management tables 204, 205, 206, 207, and 208, the TRAP Sequence IDs set in the TRAP Sequence IDs 224, 225, 226, 227, and 228 for the server A1 are referred to normally for the server A1. The TRAP Sequence ID of the last TRAP packet that has been transmitted is acquired.

  The devices N4, N5, N6, N7, and N8 search the TRAP Sequence IDs 314, 315, 316, 317, and 318 of the transmission TRAP tables 304, 305, 306, 307, and 308, respectively, using the acquired TRAP Sequence ID. Thus, the TRAP packet after the TRAP Sequence ID to be retransmitted is extracted from each of the TRAP contents 334, 335, 336, 337, and 338, and retransmitted sequentially toward the upstream server A1.

  As described above, each of the devices N1 to N8 does not receive requests or instructions from the servers A1 and A2 when the line quality deterioration state of the wireless line WL34 is restored to a normal state. Direction of receiving the line restoration notification packet received from the same direction as the direction in which the line deterioration notification packet was received in the past, regarding the transmission operation of the TRAP packet for the servers A1 and A2 The transmission operation of the TRAP packet for is resumed. That is, the transmission operation of the TRAP packet of the route that passes through the wireless line WL34 whose line quality is restored to the normal state is resumed. Thus, the TRAP packet can be transmitted to both the servers A1 and A2, and the stored transmission TRAP packet can be retransmitted. In A2, it is also possible to supplement the information regarding the status change during the unmonitorable time of each of the devices N1 to N8, which has occurred because the line quality has deteriorated.

  In addition, each device Ni (i = 1 to 8) of the terminal device monitoring system shown in FIG. 1 is a device N (i−1) adjacent to each other in addition to the above-described line deterioration notification packet and line recovery notification packet. , N (i + 1), the information set in each TRAP destination address / direction / degradation notification source table 10j is periodically acquired, and the adjacent devices NN (i−1), N (i + 1) set It is possible to check the quality degradation information of the existing line. That is, even if each device Ni (i = 1 to 8) cannot receive the line deterioration notification packet or the line restoration notification packet, it acquires the line quality deterioration information from the adjacent device. Thus, it is possible to determine whether or not to transmit the TRAP packet for status change notification to the servers A1 and A2.

  For example, the following line confirmation packet may be used. Each device Ni periodically checks the state of the line quality (line) set in the degradation notification source device 13i of the TRAP destination address / direction / degradation notification source table 10i of its own device Ni at predetermined time periods. A line confirmation packet including information on the presence / absence of a quality degradation point) is created using an IP packet and transmitted to the adjacent device N (i−1) and device N (i + 1). Note that the line confirmation packet is not only periodically transmitted, but is also transmitted to the adjacent apparatus as a response to the request from the adjacent apparatus (for example, when the line confirmation packet is transmitted). Is also possible.

  Each of the adjacent device N (i−1) and device N (i + 1) that has received the line confirmation packet includes information indicating the line deterioration point set in the line confirmation packet and the adjacent device N on the opposite side. (I-2), TRAP transmission of each device N (i−1) and device N (i + 1) based on the information indicating the line degradation point set in the line confirmation packet from the device N (i + 2) The setting contents of the degradation notification source devices 13 (i-1) and 13 (i + 1) in the destination address / direction / degradation notification source tables 10 (i-1) and 10 (i + 1) are updated, and the status change notification Controls suspension / resumption of TRAP packet transmission.

  Further, each of the adjacent devices N (i−1) and N (i + 1) that have received the line confirmation packet from the device Ni has their own device N (i−1) and device N (i + 1) in the cycle. If the line confirmation packet has not yet been transmitted from the device to the adjacent device, each of its own devices N (i−1) and N (i + 1) is triggered by the reception of the line confirmation packet from the device Ni. The state of the line quality set in each of the degradation notification source devices 13 (i-1) and 13 (i + 1) of the TRAP transmission destination address / direction / degradation notification source table 10 (i-1), 10 (i + 1) A line confirmation packet including information on the presence or absence of a line quality degradation point) is created and transferred to each of the adjacent devices N (i-2), Ni, Ni, and N (i + 2). .

  By repeating this operation sequentially, each device Ni (i = 1 to 8) not only has its own device Ni but also the TRAP destination address of each of the other devices Nj (j = 1 to 8 and j ≠ i). The information set in the degradation notification source device 13j of the / direction / degradation notification source table 10j can be acquired, and the quality degradation information of the line used by another device Nj can be confirmed.

  FIG. 6 shows a line check packet that each device Ni (i = 1 to 8) of the terminal device monitoring system shown in FIG. 1 periodically transfers to adjacent devices N (i−1) and N (i + 1). It is a table for explaining an example of the format. As illustrated in FIG. 6, the line confirmation packet includes at least a destination address 51, a transmission source address 52, and a data unit 53. In the destination address 51, an IP address of an adjacent apparatus that is a destination for transmitting the packet is set. In the transmission source address 52, the IP address of the own device that is the transmission source of the packet is set. The data unit 53 is a part for setting the line quality state, and sets information related to the line quality deterioration point when the line quality is deteriorated.

  The data section 53 includes deterioration direction information (1) 531, deterioration direction information (2) 532,..., Deterioration direction information (n) 53n, and information on the line quality deterioration points according to the number of line quality deterioration points. Has a field in which a plurality of can be set. Deterioration direction information (1) 531, deterioration direction information (2) 532,..., Deterioration direction information (n) 53n includes line direction (1) 5311 indicating the line type of the line direction in which quality deterioration has occurred. Line direction (2) 5321, ..., line direction (n) 53n1, and notification source apparatus (1) 5312, notification source apparatus (2) 5322, ... indicating the apparatus that has notified the deterioration of the line quality It includes at least each field of the device (n) 53n2.

  Next, the state in which the devices N1, N2,..., N8 transmit / receive channel confirmation packets to / from neighboring devices is shown as wireless lines WL12, WL34 used by the devices N1, N2,. , WL56, WL78 will be described with reference to FIG. 7 and FIG. FIG. 7 is an explanatory diagram for explaining an example of the transmission / reception operation of the line confirmation packet for confirming the line quality of the wireless line between the devices of the terminal device monitoring system of FIG. 1, and the wireless communication between the devices N3 and N4. An example of the transmission / reception operation in the case where the line quality deteriorates in the line WL34 is shown. FIG. 8 is an explanatory diagram for explaining another example of the transmission / reception operation of the channel confirmation packet for confirming the channel quality of the wireless channel between the devices of the terminal device monitoring system of FIG. The example of the transmission / reception operation in the case where the degradation of the line quality that has occurred in the wireless line WL34 is restored to a normal state is shown.

  As shown in FIG. 7 and FIG. 8, each of the devices N2, N3,..., N7 is periodically spaced between devices adjacent in both the upstream and downstream directions at predetermined time intervals. A line confirmation packet for confirming whether or not the quality of the wireless line has deteriorated is transmitted and received. For the device N1 located at the head in the upstream direction and the device N8 located at the tail in the downstream direction, a line confirmation packet is transmitted / received to / from one of the devices N2 and N7 adjacent to each other. I'm happy.

  Here, in FIG. 7, since the line quality is deteriorated in the wireless line WL34 between the apparatus N3 and the apparatus N4, transmission / reception of the line confirmation packet is normally performed between the apparatus N3 and the apparatus N4. I can't do it. Therefore, the device N3 is in a state where it can normally transmit and receive the line confirmation packet only with the upstream device N2. In addition, the device N4 is in a state where it can normally transmit and receive the line confirmation packet only with the downstream device N5.

  In such a case, the devices N3 and N4 are the same as the devices N1 and N8 located at both ends in the upstream direction and the downstream direction. That is, based on information set in one line confirmation packet transmitted from each of the devices N2 and N5 adjacent on the opposite side of the wireless line WL34 and successfully received, Check the quality degradation state of the line, and update the setting contents of the degradation notification source devices 133 and 133 in the TRAP destination address / direction / degradation notification source tables 103 and 104 of the devices N3 and N4, Controls suspension / resumption of transmission of a TRAP packet for status change notification.

  On the other hand, as described above, the devices N3, N4, N4, and the devices N2, N5, N6, and N7 other than the devices N3 and N4 that connect the wireless line WL34 whose line quality has deteriorated and both ends are adjacent to each other. Based on the information set in the two line confirmation packets from the apparatus, the quality degradation state of each wireless line is confirmed, and the TRAP transmission destination address / direction / direction of each apparatus N2, N5, N6, N7 is confirmed. The setting contents of the deterioration notification source devices 132, 135, 136, and 137 in the deterioration notification source tables 102, 105, 106, and 107 are updated, and the suspension / resumption of transmission of the TRAP packet for status change notification is controlled.

  Also, as shown in FIG. 8, when the degradation of the line quality that has occurred in the wireless line WL34 between the devices N3 and N4 is restored to a normal state, between the devices N3 and N4, The line confirmation packet can be normally sent and received. Therefore, the device N3 and the device N4 can normally transmit and receive the line confirmation packet to and from the adjacent devices on both sides as well as the devices other than the devices N1 and N8 located at both ends.

  Therefore, in such a case, the devices N3 and N4 are based on the information set in the two line confirmation packets from the adjacent devices on both sides, similarly to the other devices N2, N5, N6, and N7. Thus, the quality degradation state of each wireless line is confirmed, and the setting contents of the degradation notification source devices 133 and 133 in the TRAP destination address / direction / degradation notification source tables 103 and 104 of the respective devices N3 and N4 are updated. In this case, the suspension / resumption of transmission of the TRAP packet for status change notification is controlled.

  As described above, by periodically transmitting / receiving the line confirmation packet between adjacent apparatuses, each apparatus Ni (i = 1 to 8) may lose the line deterioration notification packet and the line restoration notification packet. Even if there is, since it is possible to confirm the line quality deterioration point where the line quality is deteriorated, the setting contents of the deterioration notification source apparatus 13i of the TRAP transmission destination address / direction / deterioration notification source table 10i of the own apparatus Ni Can be updated to an accurate state, and the transmission operation of the TRAP packet for status change notification can be stopped or resumed.

  In FIG. 4, FIG. 5, FIG. 7, and FIG. 8 described above, the line quality deteriorates in only one place of the wireless line WL34 between the apparatus N3 and the apparatus N4, and the remaining wireless lines are in a normal state. Explained the case. However, for example, as shown in FIGS. 9 and 10, even when a plurality of wireless lines have deteriorated line quality, the transmission / reception route of the line deterioration notification packet and the line restoration packet is divided. Each device Ni (i = 1 to 8) can confirm the state of the line quality of each wireless line by using together a line confirmation packet transmitted and received between adjacent apparatuses. Therefore, even if line quality degradation occurs in multiple wireless lines and the line degradation notification packet or line restoration packet notification does not arrive, each line confirmation packet can be used together. The device Ni (i = 1 to 8) can appropriately perform operations of stopping and restarting transmission of a TRAP packet for status change notification transmitted to the servers A1 and A2.

  FIG. 9 is an explanatory diagram for explaining how the notification of the line deterioration notification packet is divided when the line quality of a plurality of wireless lines between the devices of the terminal device monitoring system of FIG. 1 deteriorates. It is explanatory drawing explaining a mode that the notification of the line recovery notification packet transmitted when the channel quality which the radio | wireless line between the apparatuses of the terminal device monitoring system of FIG.

  In FIG. 9, degradation of the channel quality of the radio channel WL34 between the devices N3 and N4 has occurred, and further degradation of the channel quality of the radio channel WL78 between the devices N7 and N8 has occurred. In this case, the transmission operation of the line degradation notification packet is shown. As shown in FIG. 9, in the device N7 that detects the deterioration of the line quality of the wireless line WL78, an operation of transmitting a line deterioration notification packet in a broadcast format in the uplink direction opposite to the wireless line WL78 is performed. Transmission is not possible via the wireless line WL34 in which quality degradation has already occurred.

  Therefore, even if a line deterioration notification packet is transmitted from the device N7 in the opposite direction to the wireless line WL78 in which the deterioration of the line quality is detected, the transmitted line deterioration notification packet remains before the upstream wireless line WL34. Can be notified to the devices N6, N5 and N4 located in the network, but cannot be notified to the devices N3, N2 and N1 located in the upstream direction of the wireless line WL34. The notification operation of the deterioration notification packet is divided.

  Further, in FIG. 10, in the state of FIG. 9, the line quality is deteriorated in a state where the line quality deterioration state of the wireless line WL34 between the devices N3 and N4 continues. Since the line quality of the wireless line WL78 between the device N7 and the device N8 that has occurred has recovered to a normal state, a transmission operation of a line recovery notification packet indicating that effect is shown. As shown in FIG. 10, in the device N7 that detects the recovery of the line quality of the wireless line WL78, the upstream direction is the reverse direction of the wireless line WL78, which is the same direction as the direction in which the line deterioration notification packet was previously transmitted. Although the operation of transmitting the line restoration notification packet in the broadcast format is performed, it cannot be transmitted through the wireless line WL34 in which the deterioration of the line quality continues.

  Therefore, even if the line recovery notification packet is transmitted from the device N7 in the same direction as the direction in which the line deterioration notification packet is transmitted first, the transmitted line recovery notification packet is not received until the upstream radio line WL34. Although it is possible to notify the devices N6, N5, and N4 that are located, it is not possible to notify the devices N3, N2, and N1 that are located in the upstream direction of the wireless line WL34, and the line is restored. The notification operation of the notification packet is divided.

  As described above, even when line quality degradation occurs on multiple lines and the transmission operation of the line degradation notification packet and line restoration notification packet is interrupted, transmission and reception are performed regularly between adjacent devices. By using together the line confirmation packet, each device Ni (i = 1 to 8) can confirm the state of the line quality of each line, and stop transmission of TRAP packets for the servers A1 and A2. It is possible to accurately resume transmission.

(Description of operation of this embodiment)
Next, a specific operation of the terminal device monitoring system illustrated in FIG. 1 as an example of the present invention will be described in more detail using a flowchart.

  First, an example of a normal operation sequence in each of the devices N1 to N8 of the terminal device monitoring system of FIG. 1 will be described using the flowchart of FIG. FIG. 11 is a flowchart for explaining an example of normal operation in each of the devices N1 to N8 of the terminal device monitoring system of FIG. In the following description, the case of the device N3 among the devices N1 to N8 will be described as an example for easy understanding of the description.

  When any event indicating a change in situation occurs in the device N3 (step S1), the TRAP Sequence ID indicating the sequence number to be transmitted next is acquired by referring to the transmission TRAP table 303 in the device N3. The TRAP Sequence ID is set in the TRAP Sequence ID 313 of the transmission TRAP table 303, the current time is set at time 323, and the content of the event that has occurred is set and registered in the TRAP content 333 (step S2).

  Next, referring to the TRAP destination address / direction / degradation notification destination table 103 in the device N3, the IP addresses of the servers A1 and A2 registered as SNMP Managers (SNMP managers) are acquired from the destination IP address 113. Then, a TRAP packet for status change notification for the servers A1 and A2 of the acquired destination IP address is created and transmitted in both the upstream and downstream directions (step S3).

  Thereafter, in order to store the final sequence number of the transmitted TRAP packet, the TRAP Sequence set in the TRAP Sequence ID 223 corresponding to the transmission destination IP address 213 of the transmitted TRAP Sequence ID management table 201 in the device N3 is stored. The ID is updated to the sequence number of the TRAP Sequence ID of the TRAP packet transmitted in Step S3 (Step S4).

  Next, an example of a transmission sequence of the line degradation notification packet and the line restoration notification packet described in FIGS. 3 to 5 will be described with reference to the flowchart of FIG. FIG. 12 is a flowchart for explaining an example of the transmission operation of the line deterioration notification packet and the line restoration notification packet in each of the devices N1 to N8 of the terminal device monitoring system of FIG. In the following description, in order to facilitate understanding of the description, the line quality of the wireless line WL34 between the apparatuses N3 and N4 among the apparatuses N1 to N8 deteriorates, and then the line quality is normal. The operation in the device N3 when the state is recovered to the correct state will be described as an example.

  Further, in each of the devices N1 to N8, as described above, the electric field level of the wireless line used by each of the devices N1 to N8 is periodically measured at a predetermined cycle, and the line quality is deteriorated based on the measured electric field level. In order to detect the restoration of the line quality, the line deterioration electric field threshold predetermined as the electric field level for judging the deterioration of the line quality, the electric field level for judging that the line quality has been restored to the normal state in advance. The predetermined line restoration electric field threshold is set and registered in advance.

  In the flowchart of FIG. 12, the device N3 periodically acquires the current received electric field level of the wireless line WL34 used by the device N3 at regular intervals (step S11). At this time, it is confirmed whether or not a line degradation notification packet has already been transmitted to another device and is in a state for monitoring the restoration of the line quality, that is, a state in which the line degradation has been notified (step S12). ).

  If the line deterioration notification has not been made (NO in step S12), the occurrence of deterioration in the line quality of the wireless line WL34 is currently being monitored. The line degradation electric field threshold value is compared (step S13). If the received electric field level has not fallen below the line deteriorated electric field threshold (NO in step S13), the line quality of the wireless line WL34 is normal, so the process ends without doing anything, and the next received electric field Wait until the level measurement time.

  On the other hand, if the received electric field level is lower than the line deterioration electric field threshold (YES in step S13), it is determined that the line quality of the wireless line WL34 has deteriorated and packets cannot be transmitted / received. Then, a line deterioration notification packet as shown in FIG. 3 is created and transmitted to each of the devices N1 and N2 located in the upstream direction opposite to the wireless line WL34 (step S14). Thereafter, the wireless line WL34 is set to a line deterioration state, and the TRAP destination address / direction / deterioration notification source table 103 and the transmitted TRAP Sequence ID management table 203 are updated (step S15).

  In addition, if the line deterioration notification has been made in step S12 (YES in step S12), the line quality of the wireless line WL34 in which the line quality has deteriorated is restored to the normal state at the present time. Therefore, the acquired received electric field level is compared with the line restoration electric field threshold (step S16). If the received electric field level has not reached the line restoration electric field threshold or more (NO in step S16), the wireless line WL34 has not yet recovered to the normal state, so the process is terminated without doing anything, and the next Wait until the measurement time of the received electric field level.

  On the other hand, when the received electric field level has reached or exceeded the line restoration electric field threshold (YES in step S16), the line quality of the wireless line WL34 is restored to a normal state and packet transmission / reception can be resumed. 3 is created, a line restoration notification packet as shown in FIG. 3 is created, and the same direction as the direction in which the line deterioration notification packet is transmitted first, that is, in the opposite direction to the wireless line WL34 To each of the devices N1 and N2 located in the upstream direction (step S17). After that, the line degradation state of the wireless line WL34 is released, and based on the setting contents of the transmitted TRAP Sequence ID management table 203, the transmission TRAP table 303 is referred to and the stored TRAP packet is retransmitted. At the same time, the TRAP destination address / direction / degradation notification source table 103 and the transmitted TRAP Sequence ID management table 203 are updated (step S18).

  As described above, when the devices N1 to N8 detect deterioration of the channel quality of the wireless channels used by the devices N1 to N8, the devices N1 to N8 transmit a channel deterioration notification packet to other devices, When it is detected that the channel quality of the radio channel used by each of the devices N1 to N8 has been recovered from the degraded state to the normal state, a channel recovery notification packet is transmitted to another device.

  Next, an example of an operation sequence when the device Ni (i = 1 to 8) receives a line degradation notification packet from another device Nj (j = 1 to 8, j ≠ i) is used with reference to the flowchart of FIG. I will explain. FIG. 13 is a flowchart for explaining an example of the operation at the time of receiving a line deterioration notification packet in each of the devices N1 to N8 of the terminal device monitoring system of FIG. In the following description, in order to facilitate the understanding of the description, the case where the device N2 among the devices N1 to N8 has received the line degradation notification packet from the device N3 will be described as an example.

  In the flowchart of FIG. 13, when the device N2 receives the line deterioration notification packet from the device N3 (step S21), first, the reception port that has received the line deterioration notification packet is confirmed (step S22). By confirming the reception port, the reception direction in which the line degradation notification packet is received can be confirmed. In the case of the present embodiment, since the line degradation notification packet has been transmitted from the device N3, it is confirmed that the reception direction of the line degradation notification packet is from the downlink direction. It can be seen that the server A2 is ahead.

  Next, based on the reception port that has received the line degradation notification packet, that is, the reception direction, the transmission destination IP address 112 of the TRAP transmission destination address / direction / degradation notification source table 102 in the apparatus N2 becomes the transmission destination of the TRAP packet. The destination IP address of the server that is the server (in this embodiment, the IP address of the server A2 on the device N3 side), the direction 122 of the TRAP destination address / direction / degradation notification source table 102, the degradation notification source Deterioration information is set in the device 132 (step S23).

  Furthermore, the notification time information (the same time as the time when deterioration of the line quality of the wireless line WL34 occurs) included in the received line deterioration notification packet is extracted (step S24). Thereafter, the TRAP packet transmitted immediately before the line degradation occurrence time indicated by the extracted notification time information is searched based on the time 322 in the transmission TRAP table 302. Next, the searched TRAP packet is identified as the TRAP packet that has been transmitted finally before the deterioration of the line quality, and the TRAP sequence ID of the TRAP packet is acquired from the TRAP sequence ID 312 of the transmission TRAP table 302 (step). S25).

  Further, the TRAP Sequence ID 222 of the transmitted TRAP Sequence ID management table 202 is updated based on the source IP address searched in Step S23 and the TRAP Sequence ID of the last transmitted TRAP packet acquired in Step S25 ( Step S27).

  Thereafter, the transmission operation of the TRAP packet to the transmission destination IP address searched in step S23 (in this embodiment, the transmission destination IP address of the server A2 on the device N3 side) is stopped (step S27). ).

  As described above, when each of the devices N1 to N8 receives a channel degradation notification packet indicating degradation of the channel quality of the radio channel from the other devices N1 to N8, the device N1 to N8 performs the transmission operation of the TRAP packet of the route passing through the radio channel. Simultaneously with the cancellation, when the channel quality of the wireless channel is restored to a normal state, the TRAP Sequence ID, which is the sequence number of the TRAP packet to be retransmitted next, can be set to a stored state.

  Next, an example of an operation sequence when the device Ni (i = 1 to 8) receives a line restoration notification packet from another device Nj (j = 1 to 8. j ≠ i) will be described with reference to the flowchart of FIG. I will explain. FIG. 14 is a flowchart for explaining an example of the operation at the time of receiving a line restoration notification packet in each of the devices N1 to N8 of the terminal device monitoring system of FIG. In the following description, in order to facilitate understanding of the description, the case where the device N2 among the devices N1 to N8 receives the line restoration notification packet from the device N3 will be described as an example.

  In the flowchart of FIG. 14, when the device N2 receives the line restoration notification packet from the device N3 (step S31), first, similarly to the reception of the line deterioration notification packet, the reception port that has received the line restoration notification packet is first selected. Confirm (step S32). By confirming the reception port, the reception direction in which the line degradation notification packet is received can be confirmed. In the case of this embodiment, since the line restoration notification packet has been transmitted from the device N3, it is confirmed that the reception direction of the line restoration notice packet is from the downlink direction. It can be seen that there is a server A2 that is the transmission destination.

  Next, based on the reception port that has received the line restoration notification packet, that is, the reception direction, the transmission destination IP address 112 of the TRAP transmission destination address / direction / degradation notification source table 102 in the apparatus N2 becomes the transmission destination of the TRAP packet. And the direction 122 of the TRAP transmission destination address / direction / degradation notification source table 102, degradation, and the transmission destination IP address (in this embodiment, the transmission destination IP address of the server A2 on the apparatus N3 side). The deterioration occurrence information set in the notification source device 132 is deleted (step S33).

  Further, based on the transmission source IP address searched in step S33 (in this embodiment, the transmission destination IP address of the server A2 on the device N3 side), the TRAP Sequence ID 222 of the transmitted TRAP Sequence ID management table 202 is used. From the transmission destination IP address (in this embodiment, the transmission destination IP address of the server A2 on the device N3 side) located in the receiving direction is finally transmitted before the line quality deterioration occurs. The TRAP Sequence ID of the TRAP packet that has become is searched from the TRAP Sequence ID 222 of the transmitted TRAP Sequence ID management table 202 in the device N2 (Step S34).

  Thereafter, based on the TRAP Sequence ID of the last transmitted TRAP packet searched in step S34, the first TRAP packet to be retransmitted is determined by referring to the transmission TRAP table 302 in the device N2, and The status change notification information stored in the TRAP content 332 to be extracted is extracted, a TRAP packet is created, and transmitted from the downstream port to the server A2 indicated by the destination IP address searched in step S33 Thereafter, TRAP packets are sequentially generated and transmitted to the server A2 in the order stored in the transmission TRAP table 302 (step S35).

  As described above, when each of the apparatuses N1 to N8 receives a line restoration notification packet indicating the restoration of the line quality of the wireless line from the other apparatuses N1 to N8, the transmission operation of the TRAP packet of the route passing through the wireless line At the same time, by retransmitting sequentially from the TRAP packet whose transmission has been suspended when the channel quality of the wireless line has deteriorated, the dropout of the TRAP packet is prevented, and each of the apparatuses Ni (i = It becomes possible to supplement the information regarding the situation changes 1 to 8).

  Next, the device Ni (i = 1 to 8) exchanges wireless channel deterioration information by transmitting / receiving a line confirmation packet to / from adjacent devices N (i−1) and N (i + 1). An example of the operation sequence in the case of matching will be described with reference to the flowchart of FIG. FIG. 15 is a flowchart for explaining an example of the operation at the time of transmission / reception of a line confirmation packet in each of the devices N1 to N8 of the terminal device monitoring system of FIG. In the following description, in order to facilitate understanding of the description, among the devices N1 to N8, the device N3 transmits and receives the line confirmation packet shown in FIG. 6 between the adjacent devices N2 and N4. This will be described as an example.

  In the flowchart of FIG. 15, when the device N3 reaches a predetermined time period, the contents set in the degradation notification source device 133 of the TRAP destination address / direction / degradation notification source table 103 of the device N3 are referred to. Then, a line confirmation packet as shown in FIG. 6 is created and transmitted to the adjacent apparatus N2 and apparatus N4 (step S41), and the adjacent apparatus N2 and apparatus N4 return a line as a response. It is monitored whether a confirmation packet is transmitted (step S42).

  When there is a response from the adjacent device N2 or device N4 and a line confirmation packet is received (YES in step S42), based on the contents set in the received line confirmation packet, the device N3 The contents set in the degradation notification source device 133 in the TRAP transmission destination address / direction / degradation notification source table 103 are rewritten (step S43). At this time, information on one or more line quality deterioration points (information on one or more deterioration notification source devices) is newly set and registered from the state in which no information on the line quality deterioration point is set in the deterioration notification source device 133. When the state is updated, the transmission operation of the TRAP packet in the port direction toward the direction in which the registered device is located is stopped. In addition, when one or more line quality degradation point information (information of one or more degradation notification source devices) is set in the degradation notification source device 133, it is updated to a state where none is set. Restarts the transmission operation of the TRAP packet for the port direction for which the transmission operation has been stopped so far.

  On the other hand, when there is no response from the adjacent devices N2 and N4 and the line confirmation packet cannot be received (NO in step S42), wireless communication with the adjacent device that has not responded, such as the device N4, is performed. Neighboring devices that have determined that line quality degradation has newly occurred in the line WL34 and have not responded to the degradation notification source device 133 in the TRAP destination address / direction / degradation notification source table 103 of the device N3, for example The device N4 is set and registered as a line quality degradation source (step S44). Furthermore, the device N3 stops the transmission operation of the TRAP packet in the direction toward the neighboring device that has not responded, for example, the device N4.

  In each of the adjacent devices N2 and N4, when the line confirmation packet is received from the device N3, the line confirmation packet from the devices N2 and N4 has not yet been transmitted to the adjacent device N3. In response, a line confirmation packet indicating line state setting information in the devices N2 and N4 is created and transmitted to the adjacent device N3. Here, in the line confirmation packet for response, information indicating whether or not the degradation of the radio line has occurred in the direction of the port opposite to the port going to the device N3 (if it has occurred) Sets and transmits information related to the degradation notification source device indicating the occurrence location.

  As described above, each time the devices N1 to N8 reach the predetermined time period, the devices N1 to N8 perform transmission / reception operations of the line confirmation packets with the adjacent devices periodically. Even if the reception loss of the line degradation notification packet or the line restoration notification packet shown in FIG. 3 occurs, it is always possible to hold the transmission permission / inhibition of the TRAP packet in the latest state.

  Further, in the adjacent device, as a response, a line confirmation packet in which information indicating whether or not the line quality has deteriorated in the direction opposite to the direction of the apparatus from which the line confirmation packet has been transmitted is set, The line confirmation packet may be transmitted to the device from which the line confirmation packet has been transmitted. When such a line confirmation packet is received as a response, it is possible to update information on the line state only in the required line direction. Become.

(Description of the effect of this embodiment)
As described in detail above, the following effects are obtained in the present embodiment.

  In the servers A1 and A2 of the monitoring device, it is not necessary to be aware of the line deterioration state in each of the devices N1 to N8 of the terminal device that is the monitoring target device, and the line quality of each of the devices N1 to N8 Even when the degradation occurs, the transmission operation of the TRAP packet of the route passing through the line where the quality degradation has occurred can be surely stopped on each of the apparatuses N1 to N8 without any involvement of the servers A1 and A2. In addition, it is possible to prevent a reception loss of information related to a situation change transmitted from each of the devices N1 to N8 by a TRAP packet.

  Further, the servers A1 and A2 of the monitoring device store information indicating a change in the situation while the transmission operation of the TRAP packet was stopped on the devices N1 to N8 of the monitoring target device without changing the TRAP packet receiving method. When the channel quality is restored and the line quality is restored, the TRAP packet retransmission operation on the device N1 to N8 side is automatically activated to receive the TRAP packet for status change notification saved during the suspension period. It is possible to supplement the information on the status change of each of the devices N1 to N8.

  The configuration of the preferred embodiment of the present invention has been described above. However, it should be noted that such embodiments are merely examples of the present invention and do not limit the present invention in any way. Those skilled in the art will readily understand that various modifications and changes can be made according to a specific application without departing from the gist of the present invention.

10i TRAP destination address / direction / deterioration notification source table 101 TRAP destination address / direction / deterioration notification source table 102 TRAP destination address / direction / deterioration notification source table 103 TRAP destination address / direction / deterioration notification source table 104 TRAP Destination address / direction / deterioration notification source table 105 TRAP destination address / direction / deterioration notification source table 106 TRAP destination address / direction / deterioration notification source table 107 TRAP destination address / direction / deterioration notification source table 108 TRAP destination Address / direction / degradation notification source table 11i Destination IP address 12i Direction 13i Degradation notification source device 131 Degradation notification source device 132 Degradation notification source device 133 Degradation notification source device 134 Degradation notification source device 135 Degradation notification source device 136 Degradation notification Device 137 Degradation notification source device 138 Degradation notification source device 20i Sent TRAP Sequence ID management table 201 Sent TRAP Sequence ID management table 202 Sent TRAP Sequence ID management table 203 Sent TRAP Sequence ID management table 204 Sent TRAP Sequence ID management Table 205 Transmitted TRAP Sequence ID management table 206 Transmitted TRAP Sequence ID management table 207 Transmitted TRAP Sequence ID management table 208 Transmitted TRAP Sequence ID management table 21i Destination IP address 22i TRAP Sequence ID
221 TRAP Sequence ID
222 TRAP Sequence ID
223 TRAP Sequence ID
224 TRAP Sequence ID
225 TRAP Sequence ID
226 TRAP Sequence ID
227 TRAP Sequence ID
228 TRAP Sequence ID
30i transmission TRAP table 301 transmission TRAP table 302 transmission TRAP table 303 transmission TRAP table 304 transmission TRAP table 305 transmission TRAP table 306 transmission TRAP table 307 transmission TRAP table 308 transmission TRAP table 31i TRAP Sequence ID
311 TRAP Sequence ID
312 TRAP Sequence ID
313 TRAP Sequence ID
314 TRAP Sequence ID
315 TRAP Sequence ID
316 TRAP Sequence ID
317 TRAP Sequence ID
318 TRAP Sequence ID
32i Time 321 Time 322 Time 323 Time 324 Time 325 Time 326 Time 327 Time 328 Time 33i TRAP Contents 41 Destination Address 42 Source Address 43 Data Part 43a Notification Type 43b Notification Time 51 Destination Address 52 Source Address 53 Data Part 531 Degradation Direction Information (1)
532 Deterioration direction information (2)
53n Deterioration direction information (n)
5311 Line direction (1)
5321 Line direction (2)
53n1 Line direction (n)
5312 Notification source device (1)
5322 Notification source device (2)
53n2 Notification source device (n)
A1 server (monitoring server)
A2 server (monitoring server)
N1 equipment (terminal equipment)
N2 equipment (terminal equipment)
N3 equipment (terminal equipment)
N4 equipment (terminal equipment)
N5 equipment (terminal equipment)
N6 equipment (terminal equipment)
N7 equipment (terminal equipment)
N8 equipment (terminal equipment)
W11 Wired line W23 Wired line W45 Wired line W67 Wired line W82 Wired line WL12 Wireless line WL34 Wireless line WL56 Wireless line WL78 Wireless line

Claims (10)

  Two monitoring servers that monitor the status of each of one or more terminal devices connected in line from the upstream to the downstream are provided, and one of the monitoring servers is connected to the terminal device at the head of the upstream, The monitoring server is connected to the last terminal device in the downlink direction, and each of the terminal devices has a SNMP (Simple Network) when a situation change occurs in the terminal device. In the terminal device monitoring system that transmits a TRAP packet (trap packet) for status change notification compliant with the Management Protocol) standard to both of the two monitoring servers located in the upstream direction and the downstream direction, the terminal device includes the terminal When a deterioration in the quality of a line connecting a device and an adjacent terminal device is detected, the line is marked as a quality deterioration point as a deterioration detection device. Remembering, stopping the transmission operation of the TRAP packet in the direction of the quality degradation line that has become the quality degradation location, and performing the operation to save the TRAP packet for the status change notification that occurs thereafter, Create a line deterioration notification packet indicating that quality deterioration has occurred in the quality deteriorated line, transmit the packet deterioration notification packet to all the wireless devices located in the opposite direction to the quality deteriorated line, and detect the deterioration The terminal device that has received the line deterioration notification packet from a device stores the quality deterioration line as a quality deterioration point, stops the transmission operation of the TRAP packet toward the route through the quality deterioration line, and A terminal device monitoring system, which performs an operation of storing the TRAP packet for status change notification that occurs thereafter.   The terminal device that has received the line deterioration notification packet from the deterioration detection device is included in the line deterioration notification packet when performing an operation of storing the TRAP packet for a status change notification that occurs thereafter. A degradation occurrence time at which quality degradation has occurred in the quality degradation line is compared with a transmission time at which the TRAP packet for status change notification is transmitted from the terminal device, and at least the TRAP transmitted after the degradation occurrence time The terminal apparatus monitoring system according to claim 1, wherein the packet is stored as a TRAP packet to be retransmitted when the line quality of the quality deteriorated line is restored to a normal state.   When the deterioration detecting device detects that the line quality of the quality deteriorated line has been restored to a normal state, the stored memory of the quality deteriorated portion is deleted, and the direction toward the quality deteriorated line is deleted. Resuming the transmission operation of the TRAP packet, transmitting the TRAP packet stored during the transmission suspension period, and creating a line restoration notification packet indicating that the quality deteriorated line has been restored to a normal state; The transmission is sent to all the wireless devices that are located in the opposite direction to the quality-degraded line whose line quality has been recovered and was the transmission destination of the line-degradation notification packet, The terminal device that has received the line restoration notification packet deletes the stored storage of the quality degradation portion and transmits the TRAP packet toward the route passing through the quality degradation line. The terminal device monitoring according to claim 1 or 2, wherein the operation is resumed, and the operation for transmitting the TRAP packet for notification of a status change that has occurred after the time point when quality degradation has occurred on the line degradation line is performed. system.   The terminal device periodically transmits a packet for line confirmation including information on the quality degradation portion stored in the terminal device between adjacent terminal devices adjacent to the terminal device at predetermined intervals. Based on the information on the quality deterioration portion included in the line confirmation packet of the adjacent terminal device received and transmitted from the adjacent terminal device, the information on the quality deterioration portion stored in the terminal device The terminal device monitoring system according to claim 1, wherein the terminal device monitoring system is updated.   Two monitoring servers that monitor the status of each of one or more terminal devices connected in line from the upstream to the downstream are provided, and one of the monitoring servers is connected to the terminal device at the head of the upstream, The monitoring server is connected to the last terminal device in the downlink direction, and each of the terminal devices has a SNMP (Simple Network) when a situation change occurs in the terminal device. Management Protocol) A terminal device monitoring method for transmitting a TRAP packet (trap packet) for status change notification compliant to both of the two monitoring servers located in the uplink direction and the downlink direction, wherein the terminal device includes: When quality degradation of a line connecting the terminal device and an adjacent terminal device is detected, the line is stored as a quality degradation location as a degradation detection device. Then, the transmission operation of the TRAP packet in the direction of the quality degradation line that has become the quality degradation location is stopped, and the operation for storing the TRAP packet for status change notification that occurs thereafter is performed, and the quality Create a line deterioration notification packet indicating that quality deterioration has occurred in the deteriorated line, and transmit the packet to all the wireless devices located in the opposite direction to the quality deteriorated line. The terminal device that has received the line deterioration notification packet stores the quality deteriorated line as a quality deteriorated part, stops the transmission operation of the TRAP packet toward the route passing through the quality deteriorated line, and thereafter A terminal apparatus monitoring method comprising: performing an operation of storing the TRAP packet for notification of a status change that occurs.   The terminal device that has received the line deterioration notification packet from the deterioration detection device is included in the line deterioration notification packet when performing an operation of storing the TRAP packet for a status change notification that occurs thereafter. A degradation occurrence time at which quality degradation has occurred in the quality degradation line is compared with a transmission time at which the TRAP packet for status change notification is transmitted from the terminal device, and at least the TRAP transmitted after the degradation occurrence time 6. The terminal apparatus monitoring method according to claim 5, wherein the packet is stored as a TRAP packet to be retransmitted when the line quality of the quality deteriorated line is restored to a normal state.   When the deterioration detecting device detects that the line quality of the quality deteriorated line has been restored to a normal state, the stored memory of the quality deteriorated portion is deleted, and the direction toward the quality deteriorated line is deleted. Resuming the transmission operation of the TRAP packet, transmitting the TRAP packet stored during the transmission suspension period, and creating a line restoration notification packet indicating that the quality deteriorated line has been restored to a normal state; The transmission is sent to all the wireless devices that are located in the opposite direction to the quality-degraded line whose line quality has been recovered and was the transmission destination of the line-degradation notification packet, The terminal device that has received the line restoration notification packet deletes the stored storage of the quality degradation portion and transmits the TRAP packet toward the route passing through the quality degradation line. The terminal device monitoring according to claim 5 or 6, wherein the operation is resumed, and the operation for transmitting the TRAP packet for notification of a status change that has occurred after the time point when quality degradation has occurred on the line degradation line is performed. Method.   The terminal device periodically transmits a packet for line confirmation including information on the quality degradation portion stored in the terminal device between adjacent terminal devices adjacent to the terminal device at predetermined intervals. Based on the information on the quality deterioration portion included in the line confirmation packet of the adjacent terminal device received and transmitted from the adjacent terminal device, the information on the quality deterioration portion stored in the terminal device The terminal device monitoring method according to claim 5, wherein the terminal device monitoring method is updated.   When the terminal apparatus receives the line confirmation packet from the adjacent terminal apparatus, the terminal apparatus transmits the line confirmation packet from the terminal apparatus to the adjacent terminal apparatus in a period in which the line confirmation packet is received. If it has not been transmitted, the adjacent terminal device is located in the information on the quality degradation portion stored in the terminal device, triggered by reception of the line confirmation packet from the adjacent terminal device. 9. The line confirmation packet including information on a quality degradation point existing in a direction opposite to the current direction is created as a response and transmitted to the adjacent terminal device. Terminal device monitoring method.   10. A terminal device monitoring program, wherein the terminal device monitoring method according to claim 5 is implemented as a program executable by a computer.

Images