JP3174466B2 - Failure notification method and node device in multipoint ATM network - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a multipoint ATM.
The present invention relates to a failure notification method and a node device in a network.

[0002]

2. Description of the Related Art ITU-T (International Telecommunication Union-Telecommunication Standardization Sector) Recommendation I.T.T, approved by the WTSC (World Telecommunication Standardization Council) in March 1993. 610 “Broadband ISDN Operation and Maintenance Principles and Functions” (hereinafter ITU-T
I. 610), "point point A
Although the failure notification method in "TM connection" is specified, "multipoint ATM connection"
Does not specify the failure notification method.

[0003] In a failure detection notification method in a point-to-point ATM connection (hereinafter, VP: virtual path will be described as an example), a transmission path failure (or A
The device that detects the failure of the lower layer when viewed from the TM layer transmits the VP-AIS (VP-Alarm Indication Si) in the downstream direction of the ATM connection multiplexed on the failure transmission line.
gnal) send cell. The VP-AIS cell is an AT
The first device which is the end point of the M connection is terminated and detected, and it is recognized that the ATM connection has failed.

[0004] In response to the reception of the VP-AIS cell, the first device responds to the VP-FERF with respect to the ATM connection in the opposite direction to the failed ATM connection.
(VP-Far End Receive Failure) cell is transmitted. This VP-FERF cell is terminated and detected in the second device serving as the end point of the reverse ATM connection. As a result, the second device can recognize that a failure point exists in the middle of the ATM connection on the transmission side for this device.

[0005] However, ITU-TI. Under the current situation where there is no provision by 610, the above-described failure notification method in the point-to-point ATM connection is extended to the multipoint ATM connection as it is.

FIG. 8 shows a conventional point-to-point ATM.
6 shows a flow of a notification signal when a failure notification method in a connection is applied to, for example, a multipoint connection as shown in FIG. The multipoint ATM connection shown in FIG. 6 includes one transmitting end point (hereinafter, referred to as a route), a plurality of receiving end points (hereinafter, referred to as a leaf), and one or more branching connecting points. And a connecting point without a branch, which is an example in which the generality of a multipoint ATM connection (VPC: virtual path connection or VCC: virtual channel connection) is not lost.

In the example of FIG. 6, the end points of the multipoint connection are a route R and a leaf L
1, L2, L3, and L4. As connecting points, there are branch points B1, B2, B
3 and points C1 and C2 without branches. The route R is, for example, an exchange included in the network, the leaves L1 to L4 are terminals or exchanges, and the connecting points B1 to C2 are exchanges or transmission devices.

[0008] The connection is a VPC or VPC.
It corresponds to a CC and is divided into several sections (links) by the above-mentioned end point and connecting point. In this example, the link is S1 (R-C1
Interval), S2 (between C1 and B1), S3 (between B1 and C2),
S4 (between C2 and B2), S5 (between B2 and L1), S6
(Between B2 and L2), S7 (between B1 and B3), S8 (B3
9L3) and S9 (between B3 and L4). The connection can define a downstream connection from the root to the leaf and an upstream connection from the leaf to the root. The downstream connection in FIG. 6 is shown in FIG. Are shown in FIG. 7 (b). In this specification, the section Si
(I = 1 to 9), and the downlink is S
di (i = 1 to 9), Sui (i = 1 to 9) in the upward direction
Notation.

[0009]

According to the conventional failure notification method, for example, as shown in FIG.
1, when a lower layer failure occurs, the connecting point C1 adjacent to the downstream side of the failure point inserts an AIS cell into the downlink connection, and each of the leaves L1 to L4 that receives this inserts an AIS cell, as shown in FIG. ), A VP-FERF cell is returned for each uplink connection. In this case, a plurality of VP-FERF cells transmitted from the leaves L1 to L4 join one after another at each connecting point that has become a branch point of the AIS cell,
At the connecting points (B1, B2, B3) in the middle of the reverse connection, there is a problem that the bandwidth is multiplied by the number of junctions, and the route R, which is the terminal point, is multiplied by the number of leaves.

[0010] It is an object of the present invention to provide a failure notification method and a node device thereof in a multipoint ATM network that do not cause an increase in bandwidth due to merging of VP-FERF cells.

[0011]

In order to achieve the above object, a failure notification method according to the present invention uses a multipoint ATM.
In the network, a node that has detected a failure in a first connection in a downstream direction transmits a first failure notification signal (for example, a VP-AIS cell) in a downstream direction of the connection,
When a first branch node (a connecting point having a branch) in the middle of the first connection receives the first failure notification signal, a second connection in the upstream direction that forms a pair with the first connection In the downstream direction of
A second failure notification signal (for example, a VP-FERF cell) is transmitted, and each node on the second connection sequentially relays the second failure notification signal.

The second failure notification signal is transferred by each node on the second connection to the end point of the second connection. If there is a branch node in the middle, this branch node is transferred to the upstream node. Terminates the second failure notification signal received from. Note that the branch node that first receives the first failure notification signal in the first connection is a pseudo failure notification signal that replaces the first failure notification cell in the downstream direction of the first connection, for example, VP that simulates VP-AIS cell for multipoint
-Send the MAIS cell. Upon receiving the pseudo failure notification signal, each node on the first connection sequentially relays the signal to the connection endpoint.

[0013]

According to the failure notification method of the present invention, the first failure notification signal (VP-A) transmitted from the node that has detected the failure.
IS cell) is terminated at the first branch node in the middle of the first connection.
The second failure notification signal (VP-FERF cell) is returned to the second connection toward the connection route of the second failure notification signal. There is no risk of merging on the connection.

Further, a first failure notification signal (VP-AIS
The termination node that terminates the cell) flows a pseudo failure notification signal (VP-MAIS cell) instead of the first failure notification signal downstream of the first connection. ) Generates a second failure notification signal as a response operation to the normal first failure notification signal, but only relays the second failure notification signal to the pseudo failure notification signal to perform the second failure notification signal. If the failure notification signal is not generated, the pseudo failure notification signal can notify each node on the first connection of a failure while suppressing the generation of an unnecessary second failure notification signal.

[0015]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows a flow of a failure notification signal according to the present invention when a lower layer failure occurs in the section Sd1 of the first connection in the network shown in FIG. Each node configuring the network stores in advance configuration information indicating whether or not the node is a branch node. When a failure notification signal is received, the type of the received signal and the configuration information And performs a response operation according to the state of the own node based on the response.

As shown in FIG. 1A, the connecting point C1 that detects the failure of the first connection is:
Because I am not a branch point, ITU-TI. According to the provisions of 610, the first failure notification signal: AIS cell (VP-
AIS cell or VC-AIS cell) 100 is transmitted downstream of the first connection. Since the connecting point B1 receiving the AIS cell is a branch point, the connecting point B1 rewrites the payload of the received AIS cell to generate a pseudo failure notification signal: MAIS cell (V
P-MAIS cell or VC-MAIS cell) 101
And sends this to each branch route on the downstream side of the first connection, and as shown in (b), a second failure notification signal: FE for the second connection in the reverse direction.
The RF cell 200 is returned. Although a part of the reception cell is rewritten here, a new MAIS cell may be generated separately from the reception AIS cell.

In (a), upon receiving the MAIS cell, the connecting point C2 located on the first branch path branched from the connection point B1 transfers (relays) the MAIS cell downstream without processing. This MA
The further downstream branch connecting point B2 that has received the IS cell transfers the received MAIS cell downstream of each branch path without any processing. When the leaves L1 and L2 receive the MAIS cell relayed in this manner, the ITU-
TI. A state transition conforming to the rules of 610 is performed. The connecting point B3 located on the second branch road branched from the connection point B1 also has the M transmitted from the connecting point B1 similarly to the B2.
The AIS cell is received, and transferred to the downstream direction of each branch without any processing. When the leaves L3 and L4 receive the MAIS cell, the leaves L3 and L4 receive the ITU-TI. A state transition conforming to the rules of 610 is performed.

Here, as shown in (b), in the second connection in the reverse direction, the FERF 200
Returns to the first failure detection signal: AIS10
0, which is the only branch connecting point B1 initially detected, and the leaves L1 to L4 which have received the pseudo failure detection signal MAIS are in a state associated with the failure detection as in the case of receiving the first failure detection signal. Make a transition,
Second failure detection signal to reverse connection: FERF
The return operation of 200 is not performed. Accordingly, there is no occurrence of duplication of the second failure detection signal on the network, and the route R has the FER transmitted by the branch connecting point B1.
Only F200 arrives.

FIG. 2 shows a flow of a failure notification signal when a lower layer failure occurs in the section Sd2 of the first connection. In FIG. 2A, the connecting point B1 at which the failure is detected is a branch point because it is a branch point.
The MAIS 101 is sent to each branch downstream of the first connection, and as shown in FIG.
200 and sends it out to the second connection in the reverse direction. In this case, each connecting point C2, B2, which is located downstream of the connecting point B1,
The operation of B3 and the leaves L1, L2, L3, L4 is as follows:
It is the same as the case of FIG.
Only the connecting point B1 that has detected the lower layer failure returns F200.

FIG. 3 shows the flow of a failure notification signal when a lower layer failure occurs in the section Sd3 between the branch connections B1 and B2. As shown in FIG. 3A, the connecting point C2 that has detected the failure transmits the generated first failure detection signal: AIS100 in the downstream direction because it is not a branch point. AIS
The connecting point B2 that has received the cell rewrites the payload of the received AIS cell and reconstructs the pseudo failure detection signal: MAIS cell (VP
-MAIS or VC-MAIS) 101, and sends it out to each branch on the downstream side, and as shown in (b), a second failure detection signal: F in the reverse connection.
Return ERF200. The leaves L1 and L2 are the MAISs transmitted by the connecting point B2, respectively.
Receive a cell and receive the ITU-T I. A state transition conforming to the rules of 610 is performed.

As shown in (b), the FERF 200 is transmitted to the reverse connection only at the connecting point B2 where the AIS 100 is detected.
The RF cell is received at the branching connecting point B1. The connecting point B1 recognizes that a failure has occurred in the downlink connection by receiving the FERF cell. In this case, the connecting point B1 terminates the FERF cell and sends the F to the route R.
The transfer operation of the ERF cell is not performed. The reason is that, as shown in this example, when a failure occurs at one point (Sd3) on the downstream side of the branch point, the sections Sd7, Sd8,
This is because the link can be operated in Sd9 and communication between the route R and the leaves L3 and L4 is not hindered.

However, when the entire connection is managed collectively by the route R, it is necessary to notify failure information to the route. However, even in this case, since it is not necessary to quickly execute processing such as closing the entire connection, for example, the connecting point B
1 to the route R is transmitted from the ATM layer F
It does not need to be performed in the ERF cell, and communication using channels of other control planes or management planes is sufficient.

FIG. 4 shows a section Sd4 between the branch connections B1 and B2 and adjacent to the branch connection B2.
5 shows a flow of a failure notification signal when a lower layer failure occurs. As shown in (a), when a failure occurs in the section Sd4, the downstream connecting point B2 detects the failure and is a branch point, so that the same operation as the connecting point B1 in the example of FIG. In accordance with the procedure, a first failure detection signal: MAIS101 is generated and sent to each downstream branch, and (b)
As shown in the figure, a second detection signal is applied to the reverse connection:
FERF 200 is transmitted.

Upon receiving the MAIS cell, the leaves L1 and L2 of each branch path receive the ITU-TI. A state transition conforming to the rules of 610 is performed. Here, the only node that issues the FERF 200 to the reverse connection is the connecting point B2 where the lower layer failure is detected, and the FERF cell is connected to the connecting point C2.
Connecting point B1 which is relayed at
Is received. The connecting point B1 terminates the FERF cell as in the case of FIG. 3, and omits the relay to the route R.

FIG. 5 shows branch connection B2 and leaf L
1 shows a flow of a failure detection signal when a lower layer failure occurs in a section Sd5 between the failure detection signal and the first layer. As shown in (a),
If a failure occurs in the section Sd5, the leaf L1 on the downstream side detects the failure, and the ITU-TI. 610 and the second failure detection signal: FER
F200 is generated and transmitted to the connection in the reverse direction as shown in (b). The FERF cell is received by the connecting point B2, which is a branch point, and is terminated there, as in the case of the connecting point B1 in the example of FIG.

A description will be given of a node configuration for performing the above-described failure detection signal generation and transmission / reception processing, taking the connecting point B1 in the network of FIG. FIG. 9A shows the configuration of the failure notification cell processing unit of the node, FIG. 9B shows the overall configuration of the node, and FIG. 10 shows the structure of a table used for controlling the transfer of the failure notification cell. At the connecting point B1, as shown in FIG. 9A, of the user cells 305 received from the downlink transmission path 300A, the cell extraction copy unit 303 causes the failure notification cell (first failure notification cell: VP- AIS cell)
306 is extracted and supplied to the failure notification cell control unit 301.

The failure notification cell control unit 301 has a VP table 400 shown in FIG. 10. The VP table 400 has a field 402 indicating whether or not a VP connection is being set and a presence or absence of a branch corresponding to the VPI. Field 403 indicating the record. Upon receiving the VP-AIS cell, the failure notification cell control unit 301 refers to the VP table 400 using the VPI attached to the header of the cell as an address, and determines whether or not the cell itself is a branch point.

For example, the VP of the received VP-AIS cell
When I is “12”, the record corresponding to VPI (= 12) has a valid display field 402 set with a valid bit “1” indicating that a VP connection is being set, Since the bit “1” indicating the presence of a branch is set, the failure notification cell control unit 301 can determine that the failure notification cell control unit 301 is a branch node with respect to the VP connection indicated by the VP-AIS cell. In this case, the failure notification cell control unit 301 rewrites the payload of the received AIS cell,
A pseudo failure notification cell: VP-MAIS is generated and passed to the cell insertion unit 304-1, and a second failure notification cell (VP-FERF cell) is generated and transmitted to the uplink transmission path 300B. The cell is passed to the provided cell insertion unit 304-2. The cell insertion units 304-1 and 304-2 receive the VP-MAIS received from the failure notification cell control unit 301, respectively.
Cell, VP-FERF cell to the downstream transmission path 300
A 'and 300B'.

Next, referring to FIG. 1A, the transfer of the MAIS cell to the branch paths Sd3 and Sd7 will be described with reference to FIG. 9B. In FIG. 9B, branching of a cell of a downlink connection is performed by a cell branching unit 309, and merging of cells of an uplink connection is performed by a cell merging unit 308. The control of the merging and branching (for example, designation of the branching route) is performed by the cell branching unit 30
9. This is performed by the merging / branching control unit 310 in a portion connected to the cell merging unit 308. The control information is stored in the central controller 312.
Is set from

The user cell and failure notification cell processing unit 307 shown in FIG. 9A is provided in the line individual interface 311. Here, FIG.
Downlink connections at the branch connecting point B1 are 311-1a, 309, 311-1b, 31
1-2b, and the upstream connection is 311
-1b, 311-2b, 308, and 311-1a. Therefore, the failure notification cell transfer control at the branch connecting point B1 in FIG. 1 is performed by the failure notification cell processing unit 307-1a. Thereby, the MAIS cell is connected to the first branch path Sd3 (311-1b).
) And the second branch Sd7 (311-2).
b).

Next, the processing operation executed by each connecting point and the end point will be described. FIG. 11 shows a processing flow of the downlink connection performed at the connecting point. When an event occurs, the contents of the event are analyzed, and when an AIS cell is received, AIS reception processing 10 (FIG. 12) is performed. When an MAIS cell is received, MAIS reception processing 11 (FIG. 13) is detected. In this case, the lower layer failure detection processing 12 (FIG. 1)
4) is performed respectively.

As shown in FIG.
In ITU-TI. After performing the state transition (step 13) specified in 610, the connection corresponding to the receiving cell (VPC specified by the VPI of the VP-AIS cell, or VP specified by VC-AIS cell VPI-VCI
C) determines whether or not it branches at the connecting point (step 14). If it is branched, the payload of the received AIS cell is rewritten and MA
After an IS cell is generated and transmitted to each downstream branch (step 15), a FERF cell is generated and transmitted to the reverse connection (step 16). In addition,
The transmission of the FERF cell is performed according to ITU-TI. 610. If the connection corresponding to the received cell does not branch at the connecting point, the received AIS cell is transferred to the downstream direction without any processing (step 24).

In the MAIS cell reception process 11, as shown in FIG. After performing a state transition (step 18) in accordance with the rules of
The S cell is directly transferred downstream without processing (step 19).

In the lower layer fault detection processing 12, FIG.
As shown in ITU-TI. After performing the state transition (step 20) according to the provisions of 610, it is determined whether or not the active connection multiplexed on the connection (transmission path) of the failure lower layer is branched at the connecting point. (Step 21).

If the connection is branched, a MAIS cell, which is a pseudo failure detection signal, is generated and transmitted downstream (step 22), and a FERF cell is generated. ITU-TI. 610 is transmitted at a prescribed frequency (step 23). If the connection is not branched, an AIS cell, which is a first failure detection signal, is generated and transmitted downstream (step 24).

FIG. 15 shows a processing flow of the upstream connection performed at the connecting point. Upon receiving the FERF cell (step 25), the ITU-TI. 610
After the state transition (step 26) conforming to the above-mentioned rules is performed, it is determined whether or not the connection joins another branch path at the connecting point (step 27). If they join, terminate as is,
If not, the received FERF cell is transferred downstream without any processing (step 28).

FIG. 16 shows a processing flow of the downlink connection performed at the end point. The endpoint is
When an AIS cell is received, the AIS reception process 50 (FIG. 1)
7) When a MAIS cell is received, a MAIS cell reception process 51 (FIG. 18) is executed, and when a lower layer fault is detected, a lower layer fault detection process 52 (FIG. 19) is executed.

In the AIS receiving process 50, as shown in FIG. After performing a state transition (step 53) in accordance with the rules of 610, a FERF cell is generated,
This is connected to the reverse connection by ITU-TI. 610 is transmitted at a prescribed frequency (step 54). In the MAIS cell reception process 51, as shown in FIG.
I. State transition conforming to the rules of 610 (step 55)
I do. In the lower layer failure detection process 52, as shown in FIG. After performing the state transition (step 56) in accordance with the provisions of ITU-T I.610, a FERF cell is generated, and the FERF cell is connected to the reverse connection paired with the failed connection. 610 is transmitted at a prescribed frequency (step 57).

FIG. 20 shows a processing flow of the upstream connection executed at the connecting point. Upon receiving the FERF cell (step 58), the ITU-TI. 6
State transition (step 59) is performed in accordance with No. 10.

FIG. 21 is a block diagram of the ITU-TI. 610 shows an AIS cell format 500-1 specified in FIG. A
The IS cell includes a header section 501 and a payload section 502. The header section 501 has a 4-bit GFC (Generic
c Flow Control) / VPI, 24-bit VPI,
3-bit PTI (Payload Type Identifier) and 8
Bit HEC. Also, the payload section 502
Includes a function type, a failure type code, data indicating a failure location, and an error check code (CRC). Function type "0001000" indicates that the cell is an AIS cell.

FIG. 22 is a block diagram of the ITU-TI. 610 shows a format 500-2 of the FERF cell specified in 610.
FERF cells have a function type of FERF
It has the same contents as the AIS cell except that it has been changed to "00010001" to indicate that it is a cell.

FIG. 23 shows the format 5 of the MAIS cell.
An example of 00-3 is shown. The MAIS cell may have a configuration in which a malt point indication bit 503 is provided in a specific field in the payload in the AIS cell format shown in FIG. At present, ITU-T
I. In 610, only “0000”, “0001”, “0100”, and “1000” are determined as values set in the lower 4 bits of the function type field of the failure management OAM cell, and “0010” is It is unused. Therefore, as the malt point indication bit 503, for example, as shown in FIG. 24, the position 504 of the lower second bit of the function type field in the first octet of the payload 502 may be used. If the bit 504 is a malt point display bit, in the AIS cell reception processing shown in FIG. 12, the conversion from the AIS cell to the MAIS cell performed in step 15 rewrites the display bit 504 from “0” to “1”. , EDC can be recalculated.

In the embodiment, as shown in FIG. 9, the failure notification cell 306 once extracted from the main signal flow (user cell flow 305) is converted into a MAIS cell by the failure notification cell control unit 301, and this is again converted into the main cell. Although the format is such that the bit is inserted into the signal stream, the bit rewriting for converting to the MAIS cell may be performed while the AIS cell is in the main signal stream.

As described above, one embodiment of the present invention has been described, but the present invention is not limited to the above-described embodiment. For example, in the network of FIG. 6, by specifying the connecting points B1, B2, and B3 serving as branch points as "segment end points" in advance, the multipoint connection between the route R and the leaves L1 to L4 is changed to the segment "S1 + S2" , "S3 + S4",
When divided into “S5”, “S6”, “S7”, “S8”, and “S9”, these segments are all point-to-point connections. 6
10 can be applied.

In this case, instead of terminating the AIS cell / FERF cell at the connection end point, the operation of each node is defined so that the AIS cell / FERF cell is terminated at the segment end point or the connection end point. Since the AIS cell can be terminated at the branch node without notifying the end point of the connection and the FERF cell can be returned at the branch node, the failure notification signal is generated in the same manner as in the above-described embodiment. It is possible to transfer to a necessary node without causing the transfer.

[0047]

As is apparent from the above description, according to the present invention, the first failure notification signal (VP-AIS cell) is terminated at the branch node, and the second failure notification signal (VP-AIS cell) is terminated there.
(FERF cell) is returned, so that the inconvenience of redundantly returning the second failure notification signal from a plurality of locations is eliminated. Also, the branch node that has terminated the first failure notification signal transmits a pseudo failure notification cell (VP-MAIS cell) instead of the first failure notification signal to the downstream side of the connection, and transmits this to the intermediate node. , The end point (leaf node) of the connection can be notified of the connection failure by the pseudo failure notification cell. Also, when the leaf node receives the first failure notification signal, the second
If the pseudo failure notification signal is received and the second failure notification signal is suppressed from being issued, the occurrence of duplicate failure notification signals from a plurality of leaf nodes, Unnecessary merging of control cells on the root node side can be prevented.

[Brief description of the drawings]

FIG. 1 is a view for explaining a first example of a failure notification according to the present invention.

FIG. 2 is a diagram for explaining a second example of a failure notification according to the present invention.

FIG. 3 is a diagram for explaining a third example of failure notification according to the present invention.

FIG. 4 is a diagram for explaining a fourth example of a failure notification according to the present invention.

FIG. 5 is a diagram for explaining a fifth example of failure notification according to the present invention.

FIG. 6 is a diagram showing an example of the configuration of a multipoint connection.

FIG. 7 is a diagram showing the multipoint connection shown in FIG. 6 divided into downlink and uplink connections.

FIG. 8 is a diagram for explaining a problem of the related art applied to the multipoint connection of FIG. 6;

FIG. 9 is a diagram showing an example of a node configuration for implementing the present invention.

FIG. 10 is a view showing a structure of a table provided in the node.

FIG. 11 is a flowchart of a downlink connection process executed at a connecting point.

FIG. 12 is a flowchart of an AIS cell reception process executed at a connecting point.

FIG. 13: MAIS executed at a connecting point
9 is a flowchart of a cell reception process.

FIG. 14 is a flowchart of a lower layer fault detection process executed at a connecting point.

FIG. 15 is a flowchart of an uplink connection process executed at a connecting point.

FIG. 16 is a flowchart of a downlink connection process executed by an endpoint.

FIG. 17 is a flowchart of an AIS cell reception process executed by an endpoint.

FIG. 18 is a flowchart of a MAIS cell reception process executed by an endpoint.

FIG. 19 is a flowchart of a lower layer fault detection process executed at the endpoint.

FIG. 20 is a flowchart of an uplink connection process executed by an endpoint.

FIG. 21 is a diagram showing a format of an AIS cell.

FIG. 22 is a diagram showing a format of a FERF cell.

FIG. 23 is a diagram showing an example of a format of a MAIS cell.

FIG. 24 is a diagram showing another example of the format of a MAIS cell.

[Explanation of symbols]

R: route, L1-L4: leaf, C1, C2: connecting point without branch, B1-B3: connecting point with branch, S1-S9: section (link), Sd1-Sd9: downstream link, Su1-Su9 ... Upstream link, 100: AIS cell, 101: MAIS cell, 200 ...
FERF cell.

Claims (24)

(57) [Claims] (1) One sender communication device and multiple receiver
Communication device and a plurality of nodes including at least one branch node.
Notification in Multipoint ATM Network with Card
The method A signal is transmitted from the transmitting communication device to the plurality of receiving communication devices.
Of a failure detected on the first connection transmitting the
The plurality of nodes using the first connection.
Sends the first failure notification signal to the receiving communication device
And A first branch node on the first connection is
Upon receiving the first failure notification signal, detects the failure, The plurality of receiver-side communications paired with the first connection;
Transmitting a signal from the transmitting device to the transmitting communication device.
A connection to the transmitting communication device using a connection.
2 to send a failure notification signal, When the node receives the second failure notification signal,
The second failure notification signal using the second connection;
In the direction of the transmitting side communication device.
Failure notification method in a multipoint ATM network. 2. The multipoint ATM according to claim 1, wherein said second failure notification signal is transferred to said transmission side communication device through said second connection.
Failure notification method in the network. 3. A second branch node on the second connection, terminate the were received second failure notification signal, before
2. The failure notification method in a multipoint ATM network according to claim 1 , wherein the relay is not performed in the direction of the transmitting communication device . 4. The method according to claim 1, wherein the first failure notification signal is received by the second failure notification signal .
1 branch node, sends a pseudo fault notification signal in place of said first fault notification signal on said first connection, each node on the first connection, the pseudo defect notification signal 4. A failure notification method in a multi-point ATM network according to claim 1, wherein the failure notification is sequentially relayed to a connection end point. 5. The method according to claim 1, wherein the first failure notification signal is ITU-T.
I. 610 is a VP-AIS cell defined in ITU-T I.610. The multipoint AT according to any one of claims 1 to 3, wherein the multipoint AT is a VP-FERF cell defined in 610.
Failure notification method in M network. 6. The method according to claim 1, wherein the first failure notification signal is ITU-T.
I. 610, wherein the second failure notification signal is ITU-TI. The multipoint AT according to any one of claims 1 to 3, wherein the multipoint AT is a VC-FERF cell defined in 610.
Failure notification method in M network. 7. The method according to claim 7, wherein the pseudo failure notification signal is ITU-T.
I. The method of claim 4, wherein the VP-AIS cell is a cell simulating the VP-AIS cell defined in 610. 8. The system according to claim 1, wherein the pseudo failure notification signal is an ITU-T
I. The method of claim 4, wherein the VC-AIS cell is a cell simulating the VC-AIS cell defined in 610. 9. The system according to claim 4, wherein the format of the pseudo failure notification signal includes information described in the format of the first failure notification signal and information indicating multi-point use. The failure notification method in the multipoint ATM network described in the above. 10. The multipoint AT according to claim 4, wherein the format of the pseudo failure notification signal has information indicating that it is for a multipoint.
Failure notification method in M network. 11. The failure notification method in a multipoint ATM network according to claim 9, wherein the information indicating the use for multipoint is one bit. 12. The first branch node extracts the first failure notification signal from a main signal flow on the first connection, and, based on information included in the notification signal, generates the pseudo failure notification signal. 5. The method according to claim 4, wherein a failure notification signal is generated and inserted into the main signal stream. Wherein said first branch node, that said pseudo defect notification signal that rewrites a portion of the information included in the first fault notification signal flowing through the first connection on The method for notifying a failure in a multipoint ATM network according to claim 4. 14. A VCI preassign value of a failure notification cell simulating the VP-AIS cell is determined by an ITU-T
I. 8. The multipoint ATM network according to claim 7, wherein the value is "0004 (H)" indicating an end-to-end OAM flow specified by H.361, or "0003 (H)" indicating a segment OAM flow. Failure notification method. 15. The PTI pre-assigned value of a fault notification cell simulating the VC-AIS cell is defined by ITU-T
I. 9. The multipoint ATM network according to claim 8, wherein the value is “101 (B)” indicating an end-to-end OAM flow defined by H.361, or “100 (B)” indicating a segment OAM flow. Failure notification method. 16. A VCI pre-assignment value of a failure notification cell simulating the VP-AIS cell is the ITU-T
I. 361, and the VCI pre-assignment value of the VP-FERF cell is defined by ITU-TI. 8. The failure notification method in a multipoint ATM network according to claim 5, wherein the failure notification method is a spare pre-assignment value specified in 361. 17. A plurality of receptions from one transmission side communication device.
A first connection for transmitting a signal to the communication device on the side;
A plurality of receiving side communications paired with a first connection;
A second core for transmitting a signal from the device to the transmitting communication device.
Multipoint ATM network with connection
The node that has detected a failure on the first connection
Are connected to the plurality of receivers using the first connection.
Transmitting a first failure notification signal to the communication device;
Receives the first failure notification signal on the first connection
The detected branch node detects the failure, and the second connection
To the transmitting side communication device using a second
This is a failure notification method in which a failure notification signal is transmitted, and a node on the way relays these failure notification signals, wherein a connecting point of a branching node is specified in advance as a segment end point, , on a second connection, the node or connection endpoint specified segment endpoint nodes, the first fault notification signal or the first or in the case of receiving the second fault notification signal
A failure notification method in a multipoint ATM network, wherein the second failure notification signal is terminated and not relayed . 18. The method according to claim 18, wherein the first failure notification signal is an ITU-T signal.
I. 610, which is a VP-AIS cell defined in ITU-T I.610. The method according to claim 17, wherein the cell is a VP-FERF cell defined in 610. 19. The method according to claim 19, wherein the first failure notification signal is an ITU-T signal.
I. 610 is a VC-AIS cell defined in ITU-T I.610. 18. The failure notification method in a multipoint ATM network according to claim 17, wherein the failure notification is a VC-FERF cell defined in 610. 20. The VP-AIS cell and the VP-FE
The VCI preassign value indicating the RF cell is IT
U-TI. The failure notification method in a multipoint ATM network according to claim 18, wherein the failure notification method is a spare pre-assignment value according to the rule of G.361. 21. Multiple communication devices on the receiving side
A first connection for transmitting a signal to the
Pair with the connection, from the plurality of receiving communication devices
A second connection for transmitting a signal to the transmitting communication device;
A node device used in an ATM network having
hand, Any of the first mode, the second mode or the third mode
An interface that can be configured The interface in the first mode, the second mode
And a control device for setting the third mode.
Have The interface is If set to the first mode, The first connection via the first connection
Receiving the first failure notification signal indicating a failure on the
Or detecting a failure on the first connection
The transmission using the second connection.
To the side communication device Sends a second failure notification signal
A pseudo failure notification signal instead of the first failure notification signal
The plurality of receiving-side communications using the first connection
Send to the device, When set to the second mode, When the pseudo failure notification signal is received, the pseudo
The first failure notification signal using the first connection.
Transmitting to the receiving communication device, When set to the third mode, When the first failure notification signal is received, the second
The failure notification signal is transmitted using the second connection.
The pseudo failure notification is transmitted to the receiving communication device.
Transmits the second failure notification signal when receiving a signal
A node device characterized by not performing. 22. The node device according to claim 21, wherein The node device is used as a branch node on the ATM network.
Is set to the first mode when
Node device. 23. The node device according to claim 21, wherein The node device is a receiving endpoint on the ATM network.
To be set to the third mode when used as
A node device characterized by the following. 24. A communication apparatus according to claim 24, wherein said communication apparatus comprises a plurality of communication apparatuses.
A first connection for transmitting a signal to the
Pair with the connection, from the plurality of receiving communication devices
A second connection for transmitting a signal to the transmitting communication device;
A node device on the ATM network and a down, control instrumentation to be set in a defined state of the node device in advance
And the first state when the predetermined state is set.
When a first failure notification signal indicating a failure on the first connection is received via the connection, or when a failure on the first connection is detected, the second connection is used. Transmitting a second failure notification signal toward the transmitting side communication device, and transmitting a pseudo failure notification signal in place of the first failure notification signal to the first communication device.
And characterized in that it has an interface for transmitting toward said plurality of receiving communication device using the connection
Node device to perform.