JPH09191312A - Fault contact method for atm communication network - Google Patents

Abstract

PROBLEM TO BE SOLVED: To facilitate the management of a fault point without changing alarm transfer of point-to-point and processing of an equipment even in the case of point-to-multi-point communication by describing an address of its own node at a fault detecting point of an RDI cell representing a midway fault in the equipment at a termination point. SOLUTION: On the occurrence of a fault in a communication path from a communication equipment 1 to a route communication equipment 2, the communication equipment 2 sends an AIS cell denoting a detected alarm set to its fault content area and its own address set to an area representing a fault detection point to leaf communication equipments 6-8. The leaf communication equipments 6-8 detect an AIS cell and send an RDI cell denoting its own address in an area representing a fault detection point to the communication equipment 1 being a data sender. Furthermore, the reception of an AIS cell of the communication equipment being a fault detection point is reported to a monitor. The communication equipment 1 reports the reception of the RDI cell and a fault detection point area of the leaf communication equipments 6-8 to the monitor.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ATM communication fault communication method, and more particularly to point-to-multipoint fault processing and fault point management in an ATM communication network.

[0002]

2. Description of the Related Art Conventionally, regarding this kind of OAM processing,
I was doing point-to-point processing. In addition, a processing different from the point-to-point processing has been proposed for the point-to-multipoint processing.
1993 IEICE General Conference "A Study on Operation Using OAM for p-mp Connection in ATM Network" Shinji Abe, Hiroshi Yasuda (NTT). Area 516 shown in
As described above, there is a plan to give a leaf identifier for identification.

[0003]

In the plan using the leaf identifier described above, since point-to-point communication and point-to-multipoint communication are mixed in one device, different processing must be performed for each. There is a first drawback in that a leaf identifier must be newly set and a new point-to-point process using the leaf identifier must be defined.

A second drawback is that all nodes determine whether each path is point-to-point communication or point-to-multipoint communication, or use a dummy leaf identification value for point-to-point communication. It is necessary to add a function to perform leaf identification processing.

An object of the present invention is to change point-to-point alarm transfer and device processing without newly providing a leaf identifier in the alarm cell for each leaf or recognizing a path connection form in a communication device. It is to propose a method for easily managing the failure point without doing so.

[0006]

According to the fault communication method of an ATM communication network of the present invention, when a communication device other than a termination point detects a fault in a transmission line and performs alarm processing using an OAM cell, a cell for alarm display signal is provided. The AIS cell is to be transmitted, and at that time, the AIS cell shall have the address of its own node written in the failure detection point area in its payload.

More specifically, the transmission line alarm detecting means 202 for detecting an abnormality in the transmission line, and the AI for detecting the transmission line abnormality.
It has means 204 for generating and delivering S cells.

Further, when it is used as a communication device at the end point of a path, the transmission processing of an RDI cell in which the own address is indicated in the area indicating the failure detection point in the payload and the detection alarm is indicated in the failure content when the transmission path is abnormal. And also AIS
At the time of receiving a cell, the RDI cell is characterized in that its own address is shown in the area indicating the failure detection point in the payload, and the value added by the AIS cell reception is added to the failure content area. At the same time, if the transmission line is abnormal, the detected alarm content, if the AIS cell or the RDI cell is received, the AIS or RDI state of the VP or VC, its VPI / VCI value, and the failure detection point are sent to the monitoring device. Notifying is another feature.

That is, means 202 for detecting a transmission line alarm and means 20 for detecting an AIS cell and an RDI cell.
3. A means 208 for reading and latching VPI / VCI in the alarm cell, a means for reading and latching the function type, and a means 210 for reading and latching the failure type.
And a means 211 for reading out and latching a failure detection point, and an alarm state when a transmission path abnormality is detected, and an AIS or RDI state of VP / VC when an alarm cell is detected, and a VPI / VCI value and a failure detection point are monitored. And a monitoring device interface 216 as a means for notifying the device.

When used as a route of a multipoint path, one of the features is that an AIS cell is generated when a transmission path abnormality is detected and is sent to each leaf like a normal cell.

Specifically, the transmission line alarm detection means 2
02, means 204 for generating and transmitting an AIS cell when the transmission path is abnormal, and means 205 for broadcasting the cell when set as a route. It also includes that the transmission alarm detection means, the AIS cell generation / transmission means, and the broadcasting means are arranged in this order.

After that, the monitoring device collects the above-mentioned alarm information notified from each device, and in any of point-to-point and point-to-multipoint, the alarm type, the failure detection point, the failure point and the failure status depending on the VPI / VCI. It is also a feature of the present invention to perform path detection.

Specifically, the monitoring device has an alarm collecting means 303 from each device as shown in FIG. 4, and a function 304 for holding an alarm type, a failure detection point, and a VPI / VDI value,
It has a function to judge the failure point.

At this time, which leaf the received RDI cell is from is identified by the address indicated by the failure detection point in the RDF cell. For this reason, it is not necessary to add a leaf identification area to the alarm cell to add a function to the device. In addition, the device does not need to be aware of the connection form of each path to identify which path is in a failed state even in multipoint. It is possible to easily judge and detect the failure point in the monitoring device.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a diagram showing a part of an ATM communication network to which the present invention is applied, showing an example of a case where a failure occurs from a transmitting device side to a route, and FIG. 2 is a diagram showing an ATM communication network of the present invention. FIG. 3 is a diagram showing a configuration example in the case where a failure occurs from one route to one receiving device in a part of the switching network to which the failure communication method is applied. FIG. 3 is a diagram showing a configuration example of one ATM communication device Noichi. is there.

In the first embodiment of the present invention, information is transmitted by the communication device 1, the route communication device 2, the leaf communication devices 6 and 7,
8 and the communication device 3, which is an intermediate point between the transmission line and each leaf,
A network is composed of 4, 5 and each communication device is monitored by one monitoring device. The path setting is based on the setting information of the monitoring device 302 of FIG.
This is done by setting each communication device from 1.

Next, the operation of the embodiment of the present invention will be described with reference to FIG.

The operation when a failure occurs in the communication path from the communication device 1 which is the upper oscillation source to the route communication device 2 will be described.

Communication device 2 from communication device point 1 When an abnormality occurs in communication, the communication device point 2 detects an alarm. In the communication device 2, when a transmission line abnormality is detected, all VPs accommodated in the communication device 2 are detected.
Regarding the I / VCI, a detection alarm is sent to the failure content area in the payload, and an AIS cell is sent to the area indicating the failure detection point indicating its own address. At this time, since the communication device 2 is on the route, the AIS cell is sent to all the communication devices 6, 7, 8 of the leaf. Since the leaf communication devices 6, 7 and 8 detect the AIS cell, the own address and the RDI cells indicating the communication devices 6, 7 and 8 are respectively shown in the areas of the payloads indicating the failure detection points, and the communication device of the data transmission source. To send to. In addition, the monitoring device receives the AIS of VP or VC and the VIS of the AIS cell.
The PI / VCI value, the value on the failure detection point area, that is, the communication device 2 is notified. Communication device 6, 7, 8 to R
By receiving the RDI cell by receiving the DI cell and knowing the failure of the paths of the communication devices 1 to 6, the communication devices 1 to 7 and the communication devices 1 to 8 in the opposite direction, the RD of the VP or VC is detected.
The I-reception, each VPI / VCI value, and the value on the failure detection point area, that is, the communication devices 6, 7, and 8 are notified to the monitoring device.

Since the monitoring device has network setting information, it knows that a broadcast type path is established between the communication devices 1, 6, 7, and 8 and the network configuration. From each of the communication device points 6, 7 and 8, the failure detection point =
Receiving the notification that the AIS cell of the communication device 2 has been received, the paths from the communication device 1 in the directions of 6, 7, and 8 are in a failure state,
It is determined that the failure point is between the communication devices 1 and 2.
At the same time, the communication device 1 receives the communication that the RDI cells transmitted by the communication devices 6, 7, and 8 have been received. As a result, it is determined that there is no abnormality in the reverse communication and that there is no double failure.

Further, a second embodiment will be described with reference to FIG. The operation when a failure occurs in the communication from the root communication device point 2 to the communication device 3 on the path between the root communication device point 2 and one communication device point 6 of the leaf will be described.

When an abnormality occurs in communication from the communication device 2 to the communication device 3, the communication device 3 detects an alarm. The communication device 3 sends to the communication device 6 a detection alarm in the failure content area in the payload for the VPI / VCI accommodated therein and an AIS cell having its own address in the area indicating the failure detection point.

Since the communication device 6 detects the AIS cell, the communication device 6 is placed in the area of the payload showing the failure detection point.
The RDI cell indicating the address is transmitted to the communication device 1 which is the data transmission source. In addition, for monitoring equipment, VP
Or AIS reception of VC and VPI / VCI of AIS cell
Value, the value on the failure detection area, that is, the communication device 3
Notify. In the communication device 1, only the communication device 6 performs the RDI.
Since the cell is received, it is determined that the failure has occurred only in the logical paths in the directions from the communication devices 1 to 6, the RDI reception of the VP or VC, the VPI / VCI value, the value on the failure detection point area, That is, the communication device 6 is notified.

Since the monitoring device has network setting information, it knows that a broadcast type path is established between the communication devices 1 and 6, 7 and 8 and the network configuration. From communication device 6, failure detection point = AIS of communication device 3
Upon receiving the notification that the cell has been received, the communication device 1 determines that the six-direction paths are in a failure state. At the same time communication device 1
Receives a notification of RDI cell reception from the communication device 6.
This makes it possible to judge that there is no abnormality in the reverse communication and there is no double failure.

Next, the operation of the embodiment of the present invention will be described with reference to FIGS.

The format of the alarm cell of AIS cell and RDI cell is shown in FIG. A general ATM cell format 401 has an ATM header 402 and a payload 403 area. The ATM header 402 has a format 404 in the user network interface (UNI) and a network node interface (N).
NI) uses the format 405 and uses VPI for each.
Area 406 and VCI area 407, payload type (P
T) has a region 408. Generally, in the OAM cell, the payload area 403 has an area having the contents shown in the format 409. In the VP level OAM, the VCI value is OAM
For the VC level OAM, the PT value is OAM.
It is determined by taking the value for. In the alarm cell, the value of format 410 takes a value for alarm processing, and AIS,
The value of the function format 411 is used to determine the RDI. The functional information field format 412 includes a failure type 413 and a failure point 415. The case of FIG. 1 will be described. The process of the communication device 2 will be described. The cell input unit 201 is inspected by the transmission line ALM (alarm) detection unit 202, and when an alarm state at the transmission line level is detected, the alarm transfer unit 214 performs alarm transfer. In the case of a VC path, the alarm cell detection unit 203 also detects a VP alarm. Transmission line ALM detection unit 202, alarm cell detection unit 203
When an alarm is detected by any of the
AIS cell insertion is performed for all paths accommodated in 04. Since the communication device 2 is on-route, it is a normal cell or AI.
Broadcast processing is performed by the broadcast processing unit 205 without being aware of whether it is an S cell, and is output as an output 207. When the communication device 2 is communicating with the monitoring device, the detected alarm information may be notified from the monitoring device interface 216.

When a cell is received from the cell input unit 201 of the leaf device of the communication device 6, 7, or 8, an alarm cell detection unit 203 is received.
To detect the AIS cell. In this AIS cell, the alarm detected by the communication device 2 is shown in the failure type 414 in the payload 403 of the ATM cell 401, and the communication point 2 is entered in the area 415 of the failure point display. At this time, V shown in the UNI area or NNI area 406 or 407
The PI and VCI values are set by the VPI / VCI latch unit 208.
In addition, the function type latch unit 209
Further, the communication device 2 indicated by the failure type area 414 is
The alarm detected by the failure is held in the failure type latch unit 210, the communication device 2 entered in the failure point area 415 is held in the failure detection point latch unit 211, and the monitoring device interface 216 notifies the monitoring device. At the same time, RDI
The cell generation / transmission unit 212 generates an RDI cell and outputs it from the cell output unit 215. Area 4 of RDI cell at this time
06, 407, 408 and 410 are equal to the received AIS.
The function type area 411 indicates an RDI cell. Areas 415 are the communication devices 6, 7 and 8 of the leaf, respectively.
Can be replaced. However, since we did not detect the alarms on each leaf, we avoid the confusion in the area 414.
Is, for example, a value indicating NULL, or the original received AIS
In order to understand the failure content of the cell, the value assigned when the transmission path failure is detected is replaced with a value defined separately. Communication device 3
When there is an abnormality between 1 and 6, the transmission line ALM detection unit 202 detects the transmission ALM and writes it in the ATM cell 414.

In the communication device 1, the leaf communication devices 6 and 7,
Receive RDI cells from 8 asynchronously. In the alarm cell detection unit 203 of the communication device 1, the communication device 6 of the three leaves,
Detect RDI cells from 7,8. Using the area 415, the fault detection point latch unit 211 determines from which leaf of the leaf communication devices 6, 7 and 8 the cell is coming from, and based on the information of each latch unit 208, 209 and 211, the communication device of which leaf. The monitoring device interface 216 notifies the monitoring device whether the paths up to are in a failure state.

In the monitoring device, the alarms from the respective communication devices are collected by the alarm collection unit 303 and held by the alarm information holding unit 304. Further, based on the setting information of the path setting information unit 302 and the alarm information of the alarm information holding unit 304, the determining unit 305 identifies the faulty part and determines switching or route change at that time.

[0031]

As described above, the present invention distinguishes an AIS cell and an RDI cell from a normal cell at each branch point by identifying each leaf by an address which is written in a failure detection point in the RDI cell. Without warning, the alarm reception and the failure detection point are notified to the monitoring device without being aware of the point-to-point communication at each end point, and the monitoring device uses the alarm and the failure detection point notified from each end point. Even in the point-to-multipoint communication, the failure point is detected in the same manner as the point-to-point communication. Therefore, the point-to-multipoint communication has an effect of detecting the failure point in the monitoring device without adding any function. .

[Brief description of the drawings]

FIG. 1 is a diagram showing an extensional structure of an ATM communication network to which the present invention is applied, and is a diagram showing a case where a failure occurs between a device on the transmission side and a route.

FIG. 2 is a diagram showing a case where a failure occurs between a route and a receiving side device in the network shown in FIG.

FIG. 3 is a block diagram showing a configuration example of an ATM communication device forming the network shown in FIG.

FIG. 4 is a block diagram of an embodiment of the monitoring device shown in FIG.

FIG. 5 is a diagram showing a format of an alarm cell.

FIG. 6 is a diagram showing a conventional alarm cell format.

[Explanation of symbols]

 201 cell input unit 202 transmission line alarm detection unit 203 alarm cell detection unit 204 AIS cell generation / transmission unit 205 broadcast processing unit 206 own address holding unit 207 cell output unit 208 VPI / VCI latch unit 209 function type latch unit 210 failure type latch Part 211 Failure detection point latch part 212 RDI cell generation / sending part 213 Cell input part 214 Alarm transfer processing part 215 Cell output part 216 Monitoring control device interface 217 Monitoring information output part 301 Communication device interface 302 Path setting information part 303 Alarm collection part 304 Alarm information keeping unit 305 Judgment unit 401 ATM cell 402 ATM header 403 Payload 404 UNI ATM header 405 NNI ATM header 406 VPI 407 VCI 408 PT 409 OAM cell pay -D 410 OAM type 411 Function type 412 Function-specific information field 413 Alarm cell function-specific information field 414 Failure type 415 Failure point 501 ATM cell 502 ATM header 503 Payload 504 UNI ATM header 505 NNIATM header 506 VPI 507 VCI 508 PT (Payload type) 509 OAM cell Payload 510 OAM type 511 Function type 512 Function-specific information field 513 Alarm cell 514 Failure type 515 Failure point 516 Leaf identifier

Claims (2)

[Claims] 1. A fault communication method for an ATM communication device, wherein when a fault occurs on a route, an alarm process using an OAM cell which is a cell for maintenance and operation is performed, and a payload of an AIS cell which is a cell for alarm display is provided. A value indicating the node that sent the AIS cell is inserted into the failure detection point area of the
A value indicating the node that sent the RDI cell is inserted at the failure detection point in the payload of the I cell, and the VPI /
A failure communication method for an ATM communication device, which notifies a failure detection node at the same time as VCI. 2. The AIS if the fault detection node is used as a multipoint path route for cell transmission.
The fault communication method for an ATM communication device according to claim 1, wherein the cell transmission process is broadcast to all multipoint nodes.