JPH11154956A - Forced stop control system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a signal outputted from an optical network terminator issuing a warning from affecting adversely the communication between a normal optical network terminator and a subscriber terminal station equipment when one or more optical network terminators issue a warning in a system where 2-way communication between the subscriber terminal station equipment and pluralities of optical network terminators is implemented. SOLUTION: Two-way communication between a subscriber terminal station equipment 10 and pluralities of optical network terminators (1-n) is made available by adopting the optical ATM burst transmission system of a point - multi point type via 1-to-n star couplers set in the transmission path. A threshold level (e.g. three times consecutively) is placed for a warning produced from each optical network terminator in this system. The subscriber terminal station equipment 10 monitors periodically the warning outputted from each of the optical network terminators (1-n), and the subscriber terminal station equipment 10 forcibly stops any of the optical network terminators (1-n) where warning of the threshold level or the move occurs.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical AT which enables two-way communication between a subscriber terminal device and a plurality of optical network termination devices.
The present invention relates to an M burst transmission system.

[0002]

2. Description of the Related Art Conventionally, in an optical ATM burst transmission system which enables two-way communication between a subscriber terminal apparatus and a plurality of optical network terminating apparatuses, techniques for dealing with the occurrence of failures and abnormalities are as follows. There is something.

Japanese Unexamined Patent Publication No. Hei 4-287439 discloses an ATM type network in which a large number of nodes are connected to each other by a link, and when a node in the network detects a link failure, the link in which the failure is detected. Read from the VPI management table all the virtual path identifiers VPI contained in the VPI management table, form ATM cells containing the VPI and alarm information for each of the read VPIs, and send them to the switch circuit of each node. VPI and V in the ATM cell at each virtual channel termination
When the CIs match and when the VPIs match and include alarm information, the ATM cell is fetched, and the fetched virtual channel terminator determines that the path indicated by the VPI in the ATM cell has failed. Recognition eliminates the need to manage enormous amounts of information at each node for alarm transfer and eliminates the generation of a large number of ATM cells.

Japanese Patent Laid-Open Publication No. 4-35649 discloses an OAM (Op-Op) such as an alarm in an ATM communication system.
It discloses an information transfer method. When an alarm or the like is detected in the device A, the device A transfers N OAM cells indicating the occurrence of an alarm or the like to the device B. Upon receiving the transferred N OAM cells and detecting at least N ′ OAM cells indicating occurrence of an alarm or the like, it is determined that an alarm or the like has occurred in the device A. This eliminates the need for periodic management by transmitting a predetermined number of OAM cells when an alarm or the like is detected. Immediate transfer is also possible by transmitting OAM information cells in preference to user information cells. Yes, the effect on user information can be minimized.

[0005]

However, each of the above-mentioned prior arts solves the problem between the optical network terminating device and the other optical network terminating device or the subscriber terminal device in which the alarm is generated. However, there is no solution to the problem that the communication between the normal optical network unit and the subscriber terminal is not affected.

Therefore, the present invention uses a point-multipoint type optical ATM (Asynchronous Transfer Mode) burst transmission system via a 1: n star coupler installed on a transmission line to provide a subscriber. In a system that enables two-way communication between a terminal device (SLT = Subscriber LineTerminal) and a plurality of optical network terminators (ONUs: Optical Network Units), an alarm is generated when one or more optical network terminators generate an alarm. It is an object of the present invention to prevent an output signal from the optical network terminating device from adversely affecting communication between another normal optical network terminating device and the subscriber terminal device.

[0007]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a threshold value for an alarm generated in a plurality of optical network termination units connected to a subscriber terminal unit. The apparatus constantly monitors the alarms generated by the optical network terminating equipment, and the subscriber terminal equipment forcibly starts and stops the optical network terminating equipment in which the alarm equal to or more than the threshold is generated.

Further, according to the present invention, a subscriber terminal apparatus includes an alarm collection means for monitoring and collecting an alarm generated by each optical network terminal, and a threshold for generating an alarm in each optical network terminal. A threshold setting device, a comparator for comparing the collected alarm with the threshold, and a forced stop controller for cutting off communication with the optical network unit that has generated the alarm are provided.

According to the present invention, the subscriber terminal equipment forcibly starts and stops the optical network terminating device in which the alarm equal to or larger than the threshold value is generated, so that the output from the optical network terminating device in which the alarm is generated is generated. Signals can be prevented from affecting communication between the normal optical network unit and the subscriber terminal unit.

[0010]

Embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing the configuration of the embodiment.

As shown in FIG. 1, a plurality of optical network termination devices 1 to n
Is connected to the subscriber terminal device 10 via a 1: n star coupler installed on the transmission line, and a point-multipoint type optical A
It constitutes a TM burst transmission system. The subscriber terminal device 10 periodically monitors and monitors the alarm generated by each optical network termination device.
Alarm collecting means 11 for collecting, threshold setting unit 12 for setting a threshold value of an alarm generated in each optical network termination unit, comparator 1 for comparing the collected alarm with the threshold value
3, and a forced stop controller 14 for interrupting communication with the optical network terminating device that has generated the alarm.

In a system enabling two-way communication between a subscriber terminal device and a plurality of optical network termination devices, the optical network termination device 1 is provided by alarm collection means 11 on the subscriber terminal device 10 side.
.. N are periodically monitored, for example, periodically, and the subscriber terminal equipment forcibly starts and stops the optical network terminating equipment in which an alarm greater than or equal to a threshold value (for example, three consecutive times) is generated. .

Now, a specific description will be given of a case where an alarm is generated by the optical network unit 3 shown in FIG.

In the subscriber terminal device 10, a threshold value as a criterion for determining a forced stop is provided in the threshold value setting device 12 for each alarm item collected from each of the optical network termination devices 1 to n. The subscriber terminal device 10 includes optical network terminating devices 1 to
Collection of alarms from n is performed constantly or periodically. When an alarm is generated by the optical network unit 3, the comparator 13 compares a predetermined threshold value (for example, three consecutive times) with the alarm collected from the optical network unit 3. If the comparison result exceeds the threshold value, the subscriber terminal device 10 forcibly stops the optical network terminating device 3 which has generated the alarm exceeding the threshold value via the forced stop controller 14. Perform control.

As for the optical network unit in which the alarm occurrence is equal to or less than the threshold value, the alarm is continuously monitored and collected without forcibly stopping.

[0016]

As described above, according to the present invention, among a plurality of optical network terminating devices connected to a subscriber terminal device, an optical network terminating device in which an alarm equal to or higher than a threshold is generated is provided. On the other hand, when the subscriber terminal device forcibly starts and stops, the output signal from the optical network termination device that generates the alarm affects the communication between the normal optical network termination device and the subscriber terminal device. This has the effect of not having any effect.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of an embodiment.

[Explanation of symbols]

 1 to n optical network termination device 10 subscriber terminal device 11 alarm collecting means 12 threshold setting device 13 comparator 14 forced stop controller

Claims (2)

[Claims] 1. An optical ATM burst transmission system of a point-multipoint type via a 1: n star coupler installed in a transmission line, wherein both a subscriber terminal device and a plurality of optical network termination devices are used. In a system that enables two-way communication,
A threshold value of an alarm generated in each optical network terminating device is provided, and the subscriber terminal equipment constantly monitors the alarm generated by each optical network terminating device. Is a forced stop control system in which a subscriber terminal device forcibly starts and stops. 2. An optical network unit, comprising: an alarm collection unit for monitoring and collecting an alarm generated by each optical network terminal; and a threshold for setting a threshold of an alarm generated in each optical network terminal. 2. The compulsory device according to claim 1, further comprising a setter, a comparator for comparing the collected alarm with a threshold value, and a forced stop controller for cutting off communication with the optical network unit that has generated the alarm. Stop control method.