JP2000031985A - Communication fault detection control system and communication fault detection control method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To set a time-out value of each network element NE in response to a network form. SOLUTION: First whether a network form is a star form or a hub form is inquired (S1). When the network form is the star or hub form, a same time- out value is set to each NE (S2). When not (S1), number of gateways is then inquired (S3). When the number of the gateways is one, the time-out value is set (S6). When the number is two or over (S3), the arrangement of the gateway NEs is changed till the arrangement of the gateway NEs is optimum (S4, S5). When the arrangement is optimum, a time-out value of each NE is set to the arrangement of the gateway NEs (S6). Furthermore the optimum arrangement of the gateway NEs means that a time-out value of the NE that is maximum among all the NEs has a minimum value. Moreover, a time-out value is set by taking a distance between a monitor controller and the NE into account.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a communication failure detection control system and a communication failure detection control for transmitting a control command from a monitoring control device to a network element (monitoring control target) and detecting a communication failure based on a response waiting time. About the method.

[0002]

2. Description of the Related Art In a conventional communication failure detection control system of this type, the setting of a response waiting time (hereinafter referred to as a timeout time) is performed without taking into consideration the form of the network or the number of network elements. This is done with a single value for the network element.
Here, the network form is a star type, hub type,
A line type, a ring type, and a mesh type are referred to, and a network element is a router, a gateway, or the like.

According to such a conventional technique, since the network configuration is not taken into account in setting the timeout period of the response, communication control having a relatively simple control flow is achieved, and a highly reliable communication system is constructed. can do.

[0004]

However, in the above-described conventional communication failure detection control system, since the timeout period is single for all network elements, the relative position of the network element with respect to the supervisory control device is controlled. In some cases, it takes a long time to determine a failure, and unnecessary time may be spent.

In a large-scale network configuration in which there is a bypass communication path between the monitoring control device and the network element, even if a failure occurs in a communication path to a certain network element, a certain time is required. After that, even if the failure has not been recovered, a communication path is secured by the detour communication path, and the alarm that has occurred due to the failure naturally disappears, giving a strange impression to the operator of the monitoring and control device. This is because a short time-out period is set without considering the bypass communication path.

An object of the present invention is to provide a communication failure detection control system and a communication failure detection control method that reduce unnecessary waiting time until a timeout occurs.

Another object of the present invention is to provide a communication failure detection control system and communication failure detection system which eliminates the incomprehensibility of an alarm once generated when a bypass communication path is present, which disappears naturally over time. It is to provide a control method.

[0008]

According to the present invention, there is provided a communication failure detection control system for transmitting a control command from a monitoring control device to a network element and detecting a communication failure based on a response waiting time. The waiting time is based on the form of the network,
The setting is performed for each network element in consideration of the distance between the monitoring control device and the network element.

In a communication failure detection control system according to a preferred embodiment of the present invention, when there is a detour communication path between the monitoring control device and a network element, the waiting time for the network element is determined by the detour communication path. It is characterized by being determined based on.

A communication failure detection control system according to a preferred embodiment of the present invention is characterized in that a distance between the monitoring control device and the network element is a value proportional to a hop count.

In a communication failure detection control system according to a preferred embodiment of the present invention, in a network having a gateway, the waiting time of a network element in which the waiting time is the longest among all network elements is minimized. The above-mentioned waiting time is determined after optimally disposing the gateway to perform the above operation.

[0012] In a communication failure detection control system according to a preferred embodiment of the present invention, the monitoring control device includes: a data storage unit storing monitoring data and a waiting time for each network; Command processing means for reading the monitoring data and comparing the waiting time of the response to the monitoring data with the stored waiting time; and adding control information to the read monitoring data to generate a control command. A data configuration / analysis unit for deleting control information from the returned control command to be used as monitoring data, a data configuration / analysis unit for configuring the control command into a packet, and decomposing the packet into a control command; Transmitting / receiving means for transmitting and receiving the control command via a monitoring communication line. .

Further, the communication failure detection control method of the present invention comprises:
In a communication failure detection control method for transmitting a control command from a monitoring control device to a network element and detecting a communication failure based on a waiting time of a response, the waiting time is set to the form of the network and the communication between the monitoring control device and the network element. A procedure for setting for each network element in consideration of a distance, a procedure for transmitting the control command to the network, a procedure for receiving the control command from the network, and a waiting time for a response to the received control command. And comparing the set waiting time for each of the network elements.

[0014]

Next, an embodiment of the present invention will be described.

The communication failure detection control system according to the present invention transmits a control command from a monitoring control device to a network element, and detects a communication failure based on a response wait time. The configuration is set for each network element in consideration of the form of the network and the distance between the monitoring control device and the network element.

Further, the communication failure detection control method of the present invention comprises:
In a communication failure detection control method for transmitting a control command from a monitoring control device to a network element and detecting a communication failure based on a waiting time of a response, the waiting time is set to the form of the network and the communication between the monitoring control device and the network element. A procedure for setting for each network element in consideration of a distance, a procedure for transmitting the control command to the network, a procedure for receiving the control command from the network, and a waiting time for a response to the received control command. And comparing the set waiting time for each of the network elements.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a flowchart showing an outline of how to determine a timeout value corresponding to various network forms. If the network type is the star type or hub type (S1), the same timeout value is set for each NE (S2). If it is not a star type or hub type (S1), the number of gateways NE is determined (S3). If it is not 1, two or more gateways NE are arranged (S1).
4). As a result, if the arrangement of the gateway NE is optimal (S5), the timeout value of each NE is set for the arrangement (S6).
5), relocation of the gateway NE (S4) is repeated. Here, the optimal arrangement of the gateway NE means a state in which the timeout value of the NE in which the timeout value is the maximum among all the NEs is minimized.

Next, various network configurations will be described, and a method of determining a timeout time according to the present invention will be described in detail for each of them.

FIG. 2 shows a network configuration called a star type, in which a supervisory control device 100 and six network elements (hereinafter referred to as NEs) 1 to 6 are directly connected. All of the NEs 1 to 6 are theoretically monitored and controlled by the supervisory control device 100 under the same conditions. Therefore, even if there is a failure in the communication path, the failure does not affect other monitoring targets, and the same timeout value may be set to all NEs 1 to 6.

The shorter the timeout value is, the earlier the failure can be detected. However, when the network scale is large, congestion is likely to occur, and in that case, it is difficult to find the cause. Therefore, an appropriate value must be taken in consideration of this.

If there is a difference in the distance of the communication path between the monitoring control device 100 and NEs 1 to 6, N
An appropriate timeout value should be set for each of E1 to E6.
This timeout value may be a value proportional to the hop count, or may be determined by a step-like step function when the distance is short.

Note that the distance here is a concept including not only a simple physical distance but also a time required for a relay process existing between the monitoring control device 100 and the NEs 1 to 6. This time, specifically, if a failure occurs,
This is a delay time for confirming whether there is a detour route in the routing table and further confirming the direction of the gateway.

FIG. 3 shows a network configuration referred to as a hub type.
And the five NEs 11 to 15 are directly connected, so that the application of the present invention is the same as that of the star type.

FIG. 4 shows a line-type or straight-type network configuration in which the monitoring control device 102 and the five NEs 21 to 25 are sequentially connected in series. In this case, the monitoring control device 102 and the NE 21 and each NE 2
Assuming that the distance between 1 and 25 is equal, the control command & response time _Tn is approximated by the following equation.

T _n = T _c + T _r T _c = T _s1 + n × T _d + (n−1) T _p + T _{t1 Tr} = T _s2 + n × T _d + (n−1) T _p + T _t2 T _n : Command & response time of communication control T _c : Time required for command control _Tr : Time required for response control T _s1 : Command issue processing time (including transmission control processing time) in monitoring control device 102 T _s2 : Monitoring control Command issuance processing time (including reception control processing time) in the device 102 T _t1 : Command processing time in the NE (including transmission control processing time) T _t2 : Command issuance processing time in the NE (including reception control processing time) ) T _d: signal of a physical propagation delay time of the communication path difference T _p: according to the received control processing time and time and the retransmission processing of the indexing process proper transfer direction destination in the network device time n: monitoring control What from device 102 It represents your eye NE. In simple terms, it can be replaced with a hop count.

Therefore, the monitoring control device 102
The timeout value of the second NE2n is T _n It is better to set to
No.

However, the above equation shows that the gateway NE is NE2
This is an equation in the case of only one. Gateway NE is 2
Each NE, depending on which NE it is
FIG. 5 shows how the hop count changes. In addition,
In FIGS. 5 and 6 to 8, the numbers in the circles indicating NE indicate the hop count.

FIG. 5A shows NE21 and NE25, and FIG.
FIG. 5B shows a case where NE22 and NE24 are gateways, FIG. 5C shows a case where NE22 and NE24 are gateways, and FIG. 5D shows a case where NE22 and NE24 are gateways. As is clear from FIG. 5, the hop count HC of the NE having the largest hop count HC is the smallest in cases (B), (C) and (D). The optimum one may be selected in consideration of the physical distance from the monitoring control device 102, the economical position, and the like.

As shown in FIG. 6, when there is a bypass communication path between the NE 25 and the monitoring control device 102,
This also needs to be taken into account. Now, as shown in FIG. 6A, it is assumed that each of the NEs 21 to 25 has returned a control command to the supervisory control device 102 in the leftward direction. When a failure occurs at the point 20 between NE1 and NE2, the NE22 to NE25 can use the detour communication path from the NE25 to the monitoring control device 102. In this case, for example, the hop count H of the NE 22
It is better to calculate C as 4 instead of 2, and set a timeout value corresponding to this. Hop count HC 2
Then, as shown in FIG. 6 (A), an alarm is generated due to the failure occurring at the point 20, and while this failure is not recovered, as shown in FIG.
This is because if the 22 can communicate with the monitoring control device 102, the alarm will naturally disappear, giving a strange impression to the operator.

FIG. 7 shows a composite type of the star type (FIG. 2) and the line type (FIGS. 4 to 6) described above, and is called a star line type for convenience. That is, the monitoring control device 100
This is a network configuration in which a plurality of NEs are connected in series on a communication path extending from -1. Even in this star line type, a detour communication path, for example, NE6-2 and N
There may be a line directly connected to E5-3.

FIG. 8 shows a ring-type network configuration, in which the NE 36 of the six NEs 31 to 36 connected in a ring form a gateway NE, and
03 is connected. In this embodiment, for example, the NE 31 is only connected to the NE 32 and the NE 36 in the ring, and there is no shortcut route between the other NEs 33 to 35.

In the present embodiment, the timeout value of each of the NEs 31 to 36 can be determined as shown in FIG. 8A by considering the clockwise and counterclockwise communication paths if only normal operation is considered. . However, for example, as shown in FIG. 8B, when a failure occurs between the NE 35 and the NE 36, the NE 35 can detour counterclockwise.
For the same reason as described above, the hop count of the NE 35 is preferably set to 6, and a timeout value corresponding to this is preferably used.

If the NE 33 is also a gateway NE, the hop count of the NE 5 is 2, as shown in FIG. 9A during normal operation, and FIG. 9B, if a failure occurs between the NE 35 and the NE 36 as shown in FIG. Therefore, the hop count is set to 3 when the timeout value is set.

FIG. 10 shows a mesh network configuration, which differs from the ring network in that shortcuts are provided between the NE 46 and the NEs 42 and 43. In the mesh type, the feature of the hub type becomes stronger when there are many communication lines from the gateway NE, and conversely, the ring type becomes stronger when the number of communication lines coming out of the gateway NE is small.

Next, FIG. 11 shows the configuration of the supervisory control device and the NE in the ring type network illustrated in FIGS. 8 and 9. In FIG. 11, the monitoring control device 103 and N
E36 (gateway NE) is connected by a management communication line via each sender / receiver, and NE
36 and NE31, and NE36 and NE35 are connected by optical fibers via respective sender / receivers.

The monitoring and control device 103 includes NE31 to NE3.
6, monitoring data used to monitor communication lines, NE31
The database 113 stores a timeout value, etc. of the NE 36, a GUI 123, a command processing unit 133, a data configuration / analysis unit 143, and a sender / receiver 153. The timeout value stored in the database 113 is determined as described above.

When monitoring is performed, the operator uses a GUI.
An instruction to take out monitoring data from the database 113 from the database 123 is issued. The command processing unit 133 generates a control command by adding control information to the monitoring data. The data configuration / analysis unit 143 forms a packet for transmitting the control command to each NE, and is managed by the sender / receiver 153. To the communication line for communication. When the sender / receiver 153 receives a response from the NE, the data configuration / analysis unit 143 decomposes the packet into control commands, and the command processing unit 133 determines whether the response time of each NE is within the timeout value in the database 113. Check whether or not
If the timeout value is exceeded, it is regarded as a failure and G
It is displayed on the UI 123.

Since the configuration on the NE side is well known, its description is omitted.

[0040]

According to the present invention, since the configuration as described above is employed, the present invention has the effect of reducing unnecessary waiting time until timeout in communication failure detection control.

Further, it is possible to eliminate the incomprehensibility that the alarm once generated naturally disappears with the passage of time when there is a detour communication path.

[Brief description of the drawings]

FIG. 1 is a flowchart for setting a timeout value according to the present invention;

FIG. 2 is a diagram illustrating a star network to which the present invention is applied;

FIG. 3 is a diagram illustrating a hub type network to which the present invention is applied;

FIG. 4 is a diagram illustrating a line type network to which the present invention is applied;

FIG. 5 is a diagram illustrating the line network shown in FIG.
The figure which shows the difference of the hop count of each NE by the position of the gateway NE in the case of two gateway NEs

FIG. 6 is a diagram illustrating the line-type network shown in FIG.
Diagram showing a detour route when there is a detour communication route

FIG. 7 is a diagram illustrating a star line type network to which the present invention is applied;

FIG. 8 is a diagram illustrating a ring network to which the present invention is applied;

FIG. 9 is a block diagram of the ring network shown in FIG. 8;
The figure which shows the hop count of each NE when there are two gateways

FIG. 10 is a diagram illustrating a mesh network to which the present invention is applied;

FIG. 11 is a block diagram illustrating the configuration of the monitoring control device and the NE of the present invention;

[Explanation of symbols]

 1-1 NE 2-1 and 2-2 NE 3-1 NE 4-1 NE 5-1 to 5-4 NE 6-1 to 6-3 NE 1 to 6 NE 11 to 15 NE 21 to 25 NE 31 to NE 36 NE 41-46 NE 100-104 Supervisory controller 100-1 Supervisory controller 113 Database 123 GUI 133 Command processing unit 143 Data configuration / analysis unit 153 Sender / receiver

Claims (6)

[Claims] In a communication failure detection control system for transmitting a control command from a monitoring and control device to a network element and detecting a communication failure based on a response waiting time, the waiting time is determined by the form of the network and the monitoring control. A communication failure detection control system, wherein the communication failure detection control system is set for each network element in consideration of a distance between a device and the network element. 2. The method according to claim 1, wherein when there is a bypass communication path between the monitoring control device and the network element, the waiting time for the network element is determined based on the bypass communication path. Communication failure detection control system. 3. The communication fault detection control system according to claim 1, wherein a distance between the monitoring control device and the network element is a value proportional to a hop count. 4. In a network having a gateway, the waiting time is determined after optimally disposing the gateway so as to minimize the waiting time of the network element having the largest waiting time among all network elements. The communication failure detection control system according to claim 1, wherein: 5. The monitoring control device according to claim 1, further comprising: a data storage unit that stores monitoring data and a waiting time for each network; reads the monitoring data from the data storage unit; Command processing means for comparing the response waiting time with the stored waiting time; adding control information to the read monitoring data to form a control command; and deleting control information from the returned control command. Configuration / analysis means for converting the control command into packets and decomposing the packets into control commands, and transmission for transmitting / receiving the control commands via the monitoring communication line 5. A communication failure detection control system according to claim 1, wherein the communication failure detection control system comprises: 6. A communication fault detection control method for sending a control command from a monitoring control device to a network element and detecting a communication fault based on a waiting time of a response to the control command. A procedure for setting for each network element in consideration of the distance between the network element and the network element; a procedure for transmitting the control command to the network; a procedure for receiving the control command from the network; A communication failure detection control method comprising: comparing the waiting time of the response of the network element with the set waiting time for each network element.