JP2924752B2 - Failure communication method for ATM communication network - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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

[0002]

2. Description of the Related Art Conventionally, this type of OAM processing has been described.
Point-to-point processing was being performed. For point-to-multipoint processing, processing different from point-to-point processing has been proposed.
The IEICE General Conference, 995, “Study on Operation Using OAM with p-mp Connection in ATM Network” Shinji Abe and Hirofumi Yasuda (NTT) reported that each leaf is divided into multipoints. Area 516 shown in
Is proposed by assigning a leaf identifier.

[0003]

In the above-described scheme using the leaf identifier, point-to-point communication and point-to-multipoint communication coexist in one device, so that different processing must be performed for each. The first disadvantage is that a new leaf identifier must be set and a new point-to-point process using the leaf identifier must be defined.

A second disadvantage is that all nodes determine whether each path is a point-to-point communication or a point-to-multipoint communication, or use a dummy leaf identification value for the point-to-point communication. Therefore, it is necessary to add a function of performing leaf identification processing.

An object of the present invention is to change the point-to-point alarm transfer and the processing of the device without providing a new leaf identifier for each leaf in the alarm cell and without being aware of the path connection form in the communication device. It is an object of the present invention to propose a method for easily managing a failure point without using the same.

[0006]

According to the present invention, there is provided a method for reporting a failure in an ATM communication network, in which a communication device other than a terminal point performs an alarm process using an OAM cell upon detecting a transmission line failure. An AIS cell, which is a cell, is transmitted, and at that time, the AIS cell has its own node address written in a failure detection point area in its payload.

More specifically, a transmission line alarm detector 202 for detecting a transmission line for detecting a transmission line abnormality (FIG. 3)
And an AIS cell generation / transmission unit 204 for generating and transmitting an AIS cell when a transmission line is abnormal.

[0008] The terminal device receiving the AIS cell indicates its own address in the failure detection point display area in the payload of the RDI cell, which is a cell indicating that there is a failure on the way.
Sends RDI cell to information source node when failure is detected
You. At the same time, if the transmission path is abnormal, the detected alarm contents are described. If the RDI cell is received from the other end point node, the detected alarm contents are in the AIS or RDI state of VP or VC, and the VPI / VCI value and And the failure detection point to the monitoring device.

That is, means for detecting a driveway alarm
The alarm detector 202 is, an alarm cell detection unit 203 is means for detecting an AIS cell RDI cell, means der for latching read the VPI / VCI in the alarm cell
VPI / VCI latch unit 208 and a function type latch unit 210 for reading and latching the function type
And the fault that is the means to read and latch the fault type
A type latch section 210; a failure detection point latch section 211 for reading and latching a failure detection point; an alarm state when a transmission path abnormality is detected;
P / VC AIS or RDI status and VP
A monitoring device interface 216 is a means for notifying the monitoring device of the I / VCI value and the failure detection point.

[0010] In addition, in the case of a route of a multipoint path, one of the features is that when a transmission line abnormality is detected, an AIS cell is generated and transmitted to a leaf drawn like a normal cell. is there.

[0011] Specifically, the detection means of the transmission line alarm
A transmission line ALM detection unit 202 and an AI
AIS cell generation / transmission unit 204, which is a means for generating and transmitting an S cell,
It also includes a broadcast processing unit 205 that is a means for performing broadcast processing of a cell, and includes a transmission alarm detection unit, an AIS cell generation / transmission unit, and a broadcast unit in this order.

[0012] Thereafter, the monitoring device collects the above-mentioned alarm information notified from each device, and in any of the point-to-point and the point-to-multipoint, the fault type, the fault detection point, and the fault point during the fault by the VPI / VCI. Performing path detection is also a feature of the present invention.

[0013] Specifically, the monitoring device has an alarm collection section 30 is a warning collecting means from Uri the device to that shown in FIG. 4, bearing warning type, fault detection point, VPI / VCI value alarm an information holding unit 304, determine the function of determining fault point
And a setting unit 305 .

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 new leaf identification area to the alarm cell and add a function to the device.In addition, the device can determine which path is faulty even at multipoint without being aware of the connection form of each path. Judgment can be made, and the monitoring device can easily detect a failure point.

[0015]

Next, an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a diagram showing an example of a case where a failure occurs between a communication device 1 of a transmission source and a communication device 2 in a part of an ATM communication network to which the present invention is applied. FIG. 2 shows the AT of the present invention.
A part of the switching network to which the failure communication method of the M communication network is applied,
FIG. 3 is a diagram showing a configuration example when a failure occurs between the communication device 2 and the communication device 3, and FIG. 3 shows monitoring of one ATM communication device.
FIG. 3 is a diagram illustrating a configuration example of an example of a device .

In the first embodiment of the present invention, the information transmission is performed by the communication device 1, the route communication device 2, the leaf communication devices 6, 7,
A network is formed from communication devices 8 and communication devices 3, 4, and 5, which are intermediate points between the leaves defined by the transmission path, and each communication device is monitored by one monitoring device. Fig. 4 for path setting
The setting is performed by setting the communication device lacking from the interface 301 based on the setting information held by the path setting information unit 302 of the monitoring device.

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

The operation in the case where a failure has occurred in the communication path from the communication device 1 as the information source to the route communication device 2 will be described.

When an error occurs in communication from the communication device 1 to the communication device 2, the communication device 2 detects an alarm. In the communication device 2, when a transmission path abnormality is detected, all the VPs
A detection alarm fault condition area in the payload for the I / VCI, also performs an AIS cell transmission showing a self-address in an area indicated by the LP universal detection point. At this time , since the communication device 2 is on the route, the communication device 2 sends out the AIS cell to all of the leaf communication devices 6, 7, and 8. Since the leaf communication devices 6, 7, and 8 detect AIS cells,
Each is transmitted to the communication device 2 of the RDI cell / data transmission source indicating the own address and the communication devices 6, 7, and 8 in the area indicating the failure detection point in the payload. Further, the monitoring device is notified of the AS reception of the VP or the VC, the VPI / VCI value of the AIS cell, and the value on the failure detection point area, that is, the communication device 2. Further, the communication device 2 receives the RDI cells from the communication devices 6, 7, and 8 to perform RD.
The reception of the I cell, the failure of the path of the communication device 1 to 6, the path of the communication device 1 to 7 and the failure of the path of the communication device 1 to 8 in the opposite direction, the RDI reception of VP or VC and the respective PI / V
The CI value and the value on the failure detection point area, that is, the communication devices 6, 7, and 8 are notified to the devices.

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 that the network configuration is known. From each of the communication device points 6, 7, and 8, a failure detection point =
Upon receiving the notification that the communication apparatus 2 has received the AIS cell, the path in the direction of 6, 7, 8 from the communication apparatus 1 is 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 a communication indicating that the RDI cells transmitted by the communication devices 6, 7, and 8 have been received. Thereby, it is determined that there is no abnormality in the communication in the reverse direction and there is no double failure.

Further, a second embodiment will be described with reference to FIG. An operation in the case where a failure has occurred in communication from the root communication device point 2 to the communication device 3 on the route from the root communication device point 2 to one of the leaf communication device points 6 will be described.

When an error occurs in communication between the communication device 2 and the communication device 3, the communication device 3 detects an alarm. A detection alarm fault condition area in which houses the communication device 3 VPI / VCI Nitsuite payload, also sends toward the AIS cell shown the self-address in an area indicated by the fault detection point to the communication device 6.

Since the communication device 6 receives the AIS cell, the communication device 6 is located in the area indicating the failure detection point in the payload.
Is transmitted to the communication device 1 of the RDI cell # that has transmitted the data. Also, for the monitoring device, V
AIS reception of P or VC and VPI / VC of AIS cell
And I values, values that were Tsu placing the fault detection area, that informs the communication device 3. In the communication device 1, only the communication device 6
Since the DI cell is received, it is determined that a failure has occurred only in the logical path in the direction from the communication device 1 to 6, and the VP is determined.
Or notifying the RDI receiving the VPI / VCI value of VC, the values that were Tsu placing the fault point area, namely the communication device 6.

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, 8 and the configuration of the network. From the communication device 6, a failure detection point = AIS of the communication device 3
Upon receiving the notification that the cell has been received, it is determined that the path in the six directions from the communication device 1 is in a failure state. Communication device 1 at the same time
Receives a notification of reception of the RDI cell from the communication device 6.
Thereby, it can be determined that there is no abnormality in the communication in the reverse direction and there is no double failure.

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

FIG. 4 shows the format of the alarm cell of the AIS cell and the RDI cell. Reference numeral 401 denotes a general ATM cell format, which 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 has a network node interface (N
NI) uses the format 405,
Area 406 and VCI area 407, payload type (P
T) having a region 408; Generally, in an OAM cell, the payload area 403 has an area having the content shown in the format 409. VCI value is OAM in VP level OAM
For the OAM at the VC level, the PT value is
Is determined by taking the value for For the alarm cell, the value of format 410 takes the value for alarm processing,
The determination of the RDI is made based on the value of the function format 411. The format 412 of the function-specific information field includes a failure type 413 and a failure point 415. This will be described with reference to the case of FIG. Explaining the processing of the communication device 2, 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, an alarm transfer is performed by the alarm transfer unit 214. In the case of the VC path, the alarm cell detector 203 also detects a VP alarm. Transmission line ALM detector 202, alarm cell detector 203
AIS cell generation / transmission unit 2
AIS cell insertion is performed for all the paths accommodated in 04. Since the communication device 2 is on-route, it can be a normal cell or AI.
The broadcast processing is performed by the broadcast processing unit 205 without being aware of whether the cell 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.

The alarm and the leaf apparatus of the communication device 6, 7, 8 for receiving a cell from the cell input unit 201 cell detection unit 203
Detects an AIS cell. The AIS cell communication device 2 to 415 region of alarms detected by the communication device 2 is shown when a fault point table fault type 414 in the payload 403 of the ATM cell 401 is entered. At this time, the VP shown in the UNI area or the NNI areas 406 and 407 is
The value of I / VCI is stored in the VPI / VCI latch unit 208, and the function type latch unit 209 is used to indicate that the value is AIS.
Further, the alarm which is detected by the communication device 2 indicated by the fault type area 414 is output to the fault type latch unit 210 by the fault type latch unit 210.
The communication device 2 written in the failure point area 415 is held by the failure detection point latch unit 211 and is notified from the monitoring device interface 216 to the monitoring device. At the same time, an RDI cell is generated by the RDI cell generation / transmission unit 212 and transmitted from the cell output unit 215. At this time, the RDI areas 406 and 4
07, 408, 410 are equal to the received AIS. The function type area 411 indicates an RDI cell. Area 4
15 is the communication device 6 , 7 , 8 of the leaf, respectively.
Each node number is entered . However, since an alarm was not detected at each leaf, an area 414 contains, for example, a value indicating NULL, or
In order to understand the original failure content of the received AIS cell, it is replaced with a value defined separately from the value provided when the transmission path failure is detected. When an error occurs between the communication devices 3 to 6, the transmission line ALM
The detection unit 202 detects a transmission alarm and outputs the ATM cell 401
Write to.

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

In the monitoring device, an alarm from each communication device is 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 a failure location, and performs switching or route change at that time.

[0031]

As described above, the present invention distinguishes AIS cells and RDI cells from normal cells at each branch point by identifying each leaf by an address written to a failure detection point in the RDI cell. Distribution without notification, and also notifies the monitoring device of the alarm reception and the failure detection point without being aware of the point-to-point communication at each end point, and the monitoring device notifies the monitoring device of the alarm and the failure detection point notified from each end point. Even in the point-to-multipoint communication, a fault point is detected in the same manner as in the point-to-point communication, so that there is an effect that the fault point is detected in the monitoring device without particularly adding a function to the point-to-multipoint communication. .

[Brief description of the drawings]

[1] a diagram showing a partial configuration of the ATM network to which the present invention is applied, is a diagram illustrating a case where a failure occurs between the communication device 1 and passing new apparatus 2.

FIG. 2 is a block diagram showing another embodiment of the present invention;
FIG. 9 is an explanatory diagram in the case where a signal is detected between the points No. and No. 3;

FIG. 3 is a block diagram showing an example of a configuration of an ATM communication device constituting the network shown in FIG. 1;

FIG. 4 is a block diagram of an embodiment of the monitoring device shown in FIG. 1;

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

FIG. 6 is a diagram showing a conventional alert cello format.

[Description of Code] 1,2,3,4,5,6,7,8 Communication device 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 unit 211 Failure detection latch unit 212 RDI cell generation / transmission unit 213 Cell input unit 214 Alarm transfer processing unit 215 Cell output unit 216 Monitoring Control interface 217 Monitoring information output unit 301 Communication device interface 302 Path setting information unit 303 Alarm collection unit 304 Alarm information holding unit 305 Judgment unit 401 ATM cell 402 ATM header 403 Payload 404 UNI ATM header 405 NNI ATM header 406 VP 407 VCI 408 PT 409 OAM cell blue 410 OAM type 411 Function type 412 Function information field 413 Alarm cell function information field 414 Failure type 415 Failure point 501 ATM cell 502 ATM header 503 Payload 504 UNI ATM header 505 TMNNI 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)

(57) [Claims] In an ATM communication device fault communication method, when a fault occurs on a route, an alarm process is performed using an OAM cell which is a cell for maintenance and operation, and an alarm process is performed in a payload of an AIS cell which is an alarm display cell. failure detection dot region, end by inserting a value that represents the node that dispatched the AIS cell
Sent to the device endpoint, device endpoint receiving the AIS cell, middle disorders Oh
The own address is indicated in the failure detection point display area in the payload of the RDI cell which indicates the
A VPI / VCI that is sent to the information source node when a failure is detected and that has failed as alarm information to the monitoring device.
And the failure detection node, and the node receiving the RDI cell monitors the reception of the RDI.
A failure notification method for an ATM communication device, which comprises alerting a visual device . 2. When the failure detection node is used as a multi-point compatible path route for cell transmission, A
2. The fault communication method for an ATM communication device according to claim 1, wherein the IS cell transmission process performs a broadcast process to all multipoint nodes.