JP2001053802A - Method for detecting failure of packet communication network - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely detect the occurrence of a communication failure in a packet communication network. SOLUTION: While communication is not operated between guard terminal 2-1 and a guard monitor center 4 connected through a packet communication network 3, an RQ packet signal is transmitted from the terminal 2-1 to the guard monitor center 4 at prescribed time intervals. The count-up operation of a network monitor timer is operated by the guard monitor center 4, and the network monitor timer is cleared according to the reception of an RI packet signal transmitted from the packet communication network 3 according to the RQ packet signal. When the RI packet signal can not be received at prescribed time intervals, the network monitor timer stops so that the occurrence of a communication failure in the packet communication network 3 can be detected at the guard monitor center 4 side.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a packet communication network failure detection method for detecting the occurrence of a communication failure in a packet communication network.

[0002]

2. Description of the Related Art For example, there is known a mechanical security system configured to transmit and receive various security information between a mechanical security terminal and a security monitoring center using a packet communication network. By the way, in this kind of mechanical security system,
Due to its nature, it is necessary that a communication link can always be established between the mechanical security terminal and the security monitoring center.
For this reason, in a conventional machine security system using a packet communication network, the terminal multiplexing service, which is one of the packet communication systems, is used to constantly connect the security terminal device and the security monitoring center. A logical communication link is established, and when a failure occurs in the packet communication network, a failure signal from the packet communication network side is received by the security monitoring center, so that the occurrence of the failure of the packet communication network in the security monitoring center. A method has been adopted in which the presence or absence can be always grasped.

[0003]

However, according to this conventional method, if a failure has occurred in the failure monitoring function itself on the packet communication network side, the security monitoring center cannot recognize whether a communication failure has occurred. The problem described above occurs. For this reason, especially urgent such as security surveillance,
In addition, it is difficult to use a packet communication network for advanced security services that require high reliability. Therefore, in order to realize a highly reliable advanced security system, it is necessary to use expensive dedicated lines. We needed to take steps.

[0004] The problem in the case of using a packet communication network for the mechanical security system has been described above. However, in a field of application other than the mechanical security system, a highly reliable communication network is to be constructed using the packet communication network. A similar problem arises in some cases.

An object of the present invention is to provide a method for detecting a failure in a packet communication network, which can reliably and inexpensively detect occurrence of a communication failure in the packet communication network.

[0006]

Means for Solving the Problems To solve the above-mentioned problems, the present invention provides a CCITT-recommended X.400. This utilizes an RQ packet signal which is a reset request packet signal defined in 25.

[0007] The RQ packet signal is a reset request signal and is handled separately from the transmission of the content. The RQ packet signal is transmitted from the user side (terminal side) to the partner user side (terminal side) when the order of the DT packet signals transferred between the terminals is incorrect and the data transfer cannot be continued. Requesting a reset of the sequence number of the data of the DT packet signal. In the RQ packet signal,
The user can arbitrarily add a two-digit hexadecimal status code. Thus, the user can arbitrarily add the status code only to the RQ packet signal.

[0008] A sequence when one user requests the other user to reset the sequence number of the DT packet signal includes an RI (reset instruction) packet signal and an RF signal.
(Reset confirmation) The following is performed according to the combination of the packet signals. When the user A requests an RQ packet signal from the network, the network sends an RI packet signal to the user B in response to the request to instruct the network B to reset the sequence number. After resetting the sequence number, the user side B transmits a network-side RF (reset confirmation) packet signal to notify the user side A of "end of reset operation".

[0009] The reset instruction to the user side is:
It may be done from the network side. In this case, the sequence is as follows. When the network sends an RI packet signal to the user and receives an RF packet signal from the user, the reset operation ends.
Is confirmed.

[0010] Thus, when the network side receives the RQ packet signal for the reset request from the user side and sends an RI packet signal to the other user side in response to this, the network itself sends the RI packet signal to the user side. There are two ways to send a signal. To distinguish these two types of RI packet signals, a two-digit status code is added to the RQ packet signal transmitted by the network side as an identification code.
The user who has received the Q packet signal can easily know the source of the RI packet signal based on the presence or absence of the status code.

According to the first aspect of the present invention, there is provided a packet communication network failure detection method for detecting whether a failure has occurred in communication between two terminal devices connected to the packet communication network. During a period in which communication between the terminal devices is not performed, one terminal device transmits an RQ packet signal to the other terminal device at a time interval according to a preset rule, and the other terminal device transmits the RQ packet signal. The present invention is characterized in that the presence or absence of a communication failure in the packet communication network is detected based on whether or not an RI packet signal based on the above is received at the time interval.

When an RQ packet signal is transmitted from one terminal device to the other terminal device, the packet communication network receiving this RQ packet signal transmits the RQ packet signal to the other terminal device.
Sends out a packet signal. The other terminal device can receive the RI packet signal and check the identification code to know that the RQ packet signal has been transmitted from the one terminal device. If an RI packet signal based on an RQ packet signal from one terminal device is received by the other terminal device at a time interval according to a predetermined rule, it is determined that no communication failure has occurred. When the RI packet signal cannot be received at a time interval according to a predetermined rule, it is determined that a communication failure has occurred.

Here, the time interval according to the predetermined rule may be a fixed time interval. For example, a time interval according to a predetermined pattern or a time interval determined by a status code added to the RQ packet signal is used. Is also good.

According to the second aspect of the present invention, there is provided a packet communication network for detecting whether a failure has occurred in communication between a security terminal and a security monitoring center connected to the packet communication network. In the failure detection method, during a period in which communication is not performed between the security terminal device and the security monitoring center, an RQ packet is sent from the security terminal device to the security monitoring center at a time interval according to a preset rule. A signal is transmitted, and the security monitoring center detects whether or not a communication failure has occurred in the packet communication network based on whether or not an RI packet signal based on the RQ packet signal arrives at the time interval. On the point.

When an RQ packet signal is transmitted from the security terminal device to the security monitoring center, the packet communication network receiving the RQ packet signal sends the RQ packet signal to the security monitoring center.
Sends out a packet signal. The security monitoring center can receive the RI packet signal and check the identification code to know that the RQ packet signal has been transmitted from the security terminal device. If an RI packet signal based on the RQ packet signal from the security terminal device is received at the security monitoring center at a time interval according to a predetermined rule, it is determined that no communication failure has occurred. When the RI packet signal cannot be received at a time interval according to a predetermined rule, it is determined that a communication failure has occurred.

Here, the time interval according to the predetermined rule may be a fixed time interval. For example, a time interval according to a predetermined pattern or a time interval determined by a status code added to the RQ packet signal is used. Is also good.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a schematic system diagram of a mechanical security system configured to detect a communication failure in a packet communication network according to the method of the present invention. The mechanical security system 1 performs security monitoring of security terminal devices 2-1, 2-2,..., 2-N installed in security areas such as factories and offices via the existing packet communication network 3. The security monitoring center 4 is connected to the security monitoring center 4 and quickly transmits various security information obtained from the security terminal devices 2-1 to 2-N to the security monitoring center 4 via the packet communication network 3. The control information and the like output from the server as required can be transmitted to a required security terminal device via the packet communication network 3.

Some kind of failure occurs in the packet communication network 3, and communication between the security terminal devices 2-1 to 2-N and the security monitoring center 4 becomes impossible, and the security monitoring function is hindered. In this case, the security monitoring center 4 is provided with a communication failure monitoring function using an RQ packet signal so that the security monitoring center 4 can promptly grasp the situation.

FIG. 2 shows a communication processing procedure between the security monitoring center 4 and the security terminal device 2-1. Hereinafter, the communication failure monitoring function between the security terminal device 2-1 and the security monitoring center 4 will be described with reference to FIG.

When security data such as a sensor alert signal is generated in the security terminal device 2-1 due to an intruder or the like, a DT packet signal containing the security data is transmitted in step 11. This DT packet signal is sent to the host computer 4A of the security monitoring center 4 via the packet communication network 3.

When the DT packet signal is received by the host computer 4A, security data input processing is executed in step 12, and the contents of the received security data are displayed on a display device (not shown) of the host computer 4A. (Step 13). At the same time, the network monitoring timer is cleared (step 14), and ACK data for confirming that the security data has been received is transmitted to the security terminal device 2-1 (step 15). After clearing in step 14, the network monitoring timer starts counting up again.

The security terminal device 2-1 performs security data transmission completion processing by receiving the ACK data (step 16).

As described above, the security terminal device 2-1 sends out a DT packet signal every time security data is obtained, and the processing for this is executed. Security terminal 2
On the -1 side, the time elapsed since the generation of the security data is counted, and when a predetermined time, for example, 10 minutes, has elapsed since the previous generation of the security data, the next security data is not generated. Sends an RQ packet signal to the security monitoring center 4 in step 17. RQ
The packet signal is a reset request packet signal as already described in detail, and the packet communication network 3 receiving the RQ packet signal from the security terminal device 2-1 sends a reset corresponding to the RQ packet signal to the host computer 4A. An RI packet signal for instruction is transmitted. Here, the packet communication network 3 has its own host computer 4A.
In some cases, the RI computer sends out an RI packet signal to the host computer 4A. Since the RI packet signal output from the security terminal device 2-1 has a two-digit status code added as an identification code, the host computer 4A When the RI packet signal is received, it can be easily identified whether or not the RI packet signal corresponds to the RQ packet signal transmitted in step 17.

When the host computer 4A receives the RI packet signal output in response to the RQ packet signal from the security terminal 2-1 (step 1).
8) In step 19, the network monitoring timer is cleared. In response to the clearing of the network monitoring timer, an RF packet signal is transmitted from the host computer 4A to the security terminal device 2-1 (step 20), and the security terminal device 2-
The packet network check completion processing is executed by receiving this RF packet signal in step 1 (step 2).
1).

That is, in response to the generation of security data, the network monitor timer is cleared in step 14;
After the transmission of the DT packet signal due to the generation of the security data, if the DT packet signal has not been transmitted for a predetermined time (10 minutes), the RQ packet signal is transmitted (step 17). An RI packet signal transmitted from the packet communication network 3 is transmitted to the host computer 4.
The clearing of the network monitoring timer is performed by the reception of A. After that, if there is no communication between the security monitoring center 4 and the security terminal device 2-1, the RQ packet signal is sent from the security terminal device 2-1 at least once every predetermined time (10 minutes). It is sent to the monitoring center 4, whereby the network monitoring timer is cleared.

After the execution of step 21, the required time (1
If the security data has not been generated (0 minutes), an RQ packet signal is sent from the security terminal device 2-1 to the security monitoring center 4 in step 22. R at step 22
When the Q packet signal is transmitted, if any trouble occurs in the packet communication network 3 and this RQ packet signal is not input to the host computer 4A, the network monitoring timer is cleared in step 19. After a predetermined time (for example, 11 minutes longer than 10 minutes)
Times out when the time has passed.

In response to the time-out operation of the network monitoring timer, the host computer 4A cannot communicate with the security terminal 2-1 via the packet communication network 3 because a communication failure has occurred in the packet communication network 3. In response to the expiration of the network monitoring timer at step 23, a predetermined failure occurrence is displayed on the display device of the host computer 4A at step 24.

Thus, the observer of the security monitoring center 4 instructs the patrol car to rush to the security target facility where the security terminal device 2-1 is installed and to perform an inspection or the like. Appropriate measures can be taken promptly.
Therefore, no matter what kind of failure occurs in the packet communication network 3, the security monitoring center 4 can quickly detect the failure and take an appropriate action, thereby significantly improving the reliability of the mechanical security system 1. .

Note that the transmission timing of the RQ packet signal is not limited to the 10-minute interval shown in the above embodiment.
It can be set at an appropriate time interval. In addition, it is of course necessary to appropriately set the time until the network monitoring timer times out.

Although the operation of monitoring the failure of the packet communication network 3 between the security monitoring center 4 and the security terminal device 2-1 has been described above, in the present embodiment, the security monitoring center 4 and other security terminals are monitored. The same operation is performed between the devices 2-2 and 2-N. For this reason, the security monitoring center 4 can quickly detect a communication failure occurring in the packet communication network 3 for any of the security terminal devices 2-1 to 2-N.

Although the embodiment of the present invention has been described by taking a mechanical security system as an example, the method for detecting a failure in a packet communication network according to the present invention is not intended only for the use of the mechanical security system. The present invention can be similarly applied to detection of a communication failure in various other communication systems performed through the communication.

[0033]

According to the present invention, when a communication failure occurs in a packet communication network, the occurrence of the failure can be reliably and promptly detected between any two terminal devices communicating via the packet communication network. Therefore, a highly reliable communication system can be implemented.

Also, in a mechanical security system for exchanging signals for security between one or a plurality of security terminal devices and a security monitoring center using a packet communication network, communication in the packet communication network is performed. When a failure occurs, the occurrence of the failure can be detected quickly and reliably regardless of the content of the failure, so that an extremely reliable machine security service can be provided.

[Brief description of the drawings]

FIG. 1 is a schematic system diagram showing an example of an embodiment of a machine security system configured to detect a communication failure in a packet communication network according to the method of the present invention.

FIG. 2 is an explanatory diagram for explaining a communication processing procedure between a security monitoring center and a security terminal device in the machine security system shown in FIG. 1;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Mechanical security system 2-1 to 2-N Security terminal device 3 Communication network 4 Security monitoring center 4A Host computer

Claims (2)

[Claims] 1. A packet communication network fault detection method for detecting whether a fault has occurred in communication between two terminal devices connected to a packet communication network, wherein the communication between the terminal devices is performed. During the non-performing period, an RQ packet signal is transmitted from one terminal device to the other terminal device at a time interval according to a preset rule, and the RI packet signal based on the RQ packet signal is transmitted to the other terminal device. A method for detecting a failure in a packet communication network, comprising detecting whether or not a communication failure has occurred in the packet communication network based on whether or not a call arrives at a time interval. 2. A failure detection method for a packet communication network for detecting whether a failure has occurred in communication between a security terminal device and a security monitoring center connected to the packet communication network, During a period in which no communication is performed between the security terminal and the security monitoring center, an RQ packet signal is transmitted from the security terminal to the security monitoring center at a time interval according to a preset rule. Packet communication characterized in that a monitoring center detects the occurrence of a communication failure in the packet communication network based on whether an RI packet signal based on the RQ packet signal arrives at the time interval. Network failure detection method.