JPH1132067A - Transmission system and communication method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the communication efficiency of a transmission system through elimination of a fault frame with the possibility of circulating or wondering on a transmission path by the data destruction or the like of the reception destination and transmission origin of a communication frame, due to noise or the like on the transmission path in the node of a prescribed number order. SOLUTION: Assume that a node D of the reception destination of transmission data 80 has gone down by a fault. Since a system transmission path is in constitution for bypassing the down node, the data 80 which cannot be received in the node D are infinitely circulated on the transmission path 1 in the state. Then, the transmission data 80 which bypass the node D are successively passed through the respective nodes inside a loop by repetition, while reducing the value NC of a circulating processing identifier 83 one by one and reach the node N. The circulating data processing part of the node N subtracts '1' from the value of the circulating processing identifier 83, and when the value becomes '0', stops the repetition of the reception data and abandons and eliminates them.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transmission system in which a plurality of communication processors transmit and receive data via a transmission line, and more particularly to a method for removing a faulty frame on the transmission line.

[0002]

2. Description of the Related Art When a plurality of communication apparatuses transmit and receive data via a loop transmission path, a transmitting side attaches a transmission destination address (reception destination identification information) in a communication frame and transmits the data. If the communication frame received is not addressed to itself, the receiving side repeats the transmission frame as it is.On the other hand, if the communication frame is addressed to itself, the receiving side performs required reception processing and repeats the transmission line to erase the frame. Not performed. That is, the received frame used on the receiving side is deleted. However, when the receiving side fails, the communication frame may go around the transmission path indefinitely.

[0003] Therefore, the transmitting side sets the receiving party identification information and the receiving destination response information and transmits it. On the receiving side, if the communication frame is addressed to itself, the receiving side sets a reception completion flag in the receiving destination response information and gives the transmitting side a transmission completion flag. There is known a communication system in which a transmission side returns a frame transmitted by itself on the transmission side (for example, JP-A-6-291773; Reference 1).

On the other hand, in recent years, the standardization of the ATM (asynchronous transfer mode) system has been progressing, and it has begun to spread as a large-capacity multimedia network. The standard of the ATM system supports a function of guaranteeing a transmission band and a communication delay time required for communication, and is particularly effective for image transmission in which real-time performance is severe.

[0005] Recently, there has been an attempt to apply the ATM method to a plant monitoring / control system network to improve real-time performance, speed-up, openness, multimedia support, and the like. For example, as described in the Proceedings of the Communication Society Conference of the Institute of Electronics, Information and Communication Engineers in 1996 (Cited Example 2), there is a proposal of a loop-type transmission system using a cell looping countermeasure method.

[0006] Even in a network to which the ATM system is applied,
Erasing a failed frame is a problem. In the above cited example 2, in a loop transmission system in which a plurality of communication nodes are connected in a loop, a unique node number is given to each node in the system, and the nodes are connected such that the node numbers are arranged in ascending order on the loop. I do. Each node periodically notifies its immediate downstream node of its own node number so that a leaving node can be detected in the event of a failure, and other nodes remove communication frames to be removed by the leaving node from the transmission path instead. I do.

[0007]

In the faulty frame erasing method of the cited reference 1, if the receiving station of the frame destination fails and the transmitting station fails immediately after the transmission of the frame, the frame is sent from anybody. However, there is still a problem that an unnecessary transmission frame goes around the transmission loop infinitely.

In the transmission system according to the cited example 2,
There is a restriction on the system configuration that connects nodes such that node numbers are arranged in ascending order on the loop. Under this constraint, when adding a new node in the transmission system, it is necessary to connect the additional node after the node with the last node number, or to set all node numbers again in ascending order However, there is a problem that it is difficult to flexibly change a system such as adding a node online while the transmission system is operating.

SUMMARY OF THE INVENTION An object of the present invention is to provide a method and a transmission system which overcome the above-mentioned problems of the prior art and which can reliably delete unnecessary frames on a transmission line without providing a node number of a node in a loop and restrictions. Is to do.

It is another object of the present invention to provide a communication method and a transmission system for surely erasing unnecessary frames that stray on a transmission line without being erased due to the occurrence of a node that has left due to a failure in a network not based on a loop configuration.

It is still another object of the present invention to provide a communication method and a transmission system for securely erasing unnecessary frames in a network for performing data transmission by an asynchronous transfer mode (ATM) transmission method.

[0012]

SUMMARY OF THE INVENTION An object of the present invention is to provide a communication method for a transmission system in which a plurality of nodes are coupled to a transmission path and mutually transmit and receive data via the transmission path. The node assigns, to the communication frame carrying the data to be transmitted, a node passing identifier reflecting the number of passed nodes together with the receiving node identifier. If the received communication frame is not addressed to itself, Updating the value of the node passage identifier before repeating a frame on the transmission line, and stopping the repeat when it is recognized from the value that the number of node passages has reached a predetermined number set in advance. Is achieved by

In the case of a single cast, the predetermined number is:
The value is set to a value that exceeds the total number of nodes from the source node to the destination node. In the case of multicast, a transmission node identifier is added to the communication frame to enable transmission source erasure, and the transmission frame is set to a value exceeding the total number of nodes on the transmission path until the transmitted communication frame returns to the transmission source. Set a predetermined number.

[0014] The node passing identifier is initialized to 0, and 1 is added each time the node passes, and when the predetermined number is reached, the communication frame is determined to be a faulty frame and is deleted from the transmission path. Alternatively, the predetermined number is initially set, 1 is subtracted each time a node passes, and the count is deleted when it becomes 0.

When the asynchronous transfer mode (ATM) transmission method is applied to the communication method of the transmission system, the communication frame is read as a cell, and the node passing identifier is added to a virtual path identifier (VPI) of the cell header. It is characterized in that a receiving node identifier is assigned to a virtual channel identifier (VCI) at the time of single cast or the receiving node identifier and the sending node identifier are assigned at the time of multicast.

[0016] Thus, even in a network to which the ATM transmission system is applied, a faulty frame can be easily removed without having to arrange the order of nodes in the system as in the conventional case.

In the case where a large amount of data is transmitted at one time, when the reception identifier in the frame is destroyed due to noise or the like during transmission, a failure frame cannot be received at the original destination node. As a result, the circuit circulates or strays on the transmission path, and much of the transmission path band is wastefully occupied. In addition, even in the case of monitoring using the node passing identifier according to the present invention, the transmission path band up to the node whose identifier value is a predetermined number is wastefully occupied.

Accordingly, the present invention provides a method for dividing a data transmitted by the transmission source node at one time into a plurality of pieces of data, and for each communication frame carrying each of the divided data, the reception node identifier and the node passage identifier. And giving a division order identifier indicating the division order of the data,
Continuously transmit, each node on the transmission path, when the received communication frame is addressed to itself, based on the division order of the division order identifier, performs predetermined reception processing when receiving all the divided data, If not, the received divided data is discarded.On the other hand, if the received communication frame is not addressed to itself, the value of the node pass identifier is updated before the communication frame is repeated on the transmission line. When it is determined that the number of passages has reached a predetermined number set in advance, the repeat is stopped.

[0019] In the transmission system for realizing the above-described method of the present invention, the node performs a transmission process including giving a node passing identifier reflecting a node passing number together with a receiving node identifier to a communication frame mounting data to be transmitted. Do
On the other hand, transmission / reception processing means for performing reception processing when the received communication frame is addressed to itself, and performing transmission processing for repeating the communication frame to the transmission path when not addressed to itself, the node of the received communication frame. A failure frame discarding means for updating the value of the pass identifier and, when it is recognized from the value that the number of passed nodes has reached a predetermined number set in advance, canceling the repeat is provided. .

When the transmission line has a non-loop shape such as a mesh shape or a tree shape, the node includes a plurality of transmission line interfaces for connecting to a plurality of transmission lines having the same and different communication directions. When the frame is not addressed to itself, the transmission / reception processing means has a relay function of passing the communication frame to a transmission path interface in a communication direction corresponding to the receiving node identifier.

[0021]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, a first embodiment in which a network has a loop shape, a second embodiment in which ATM is applied, and a third embodiment in which a network has a loop shape will be described in detail with reference to the drawings.

[Embodiment 1] FIG. 1 shows a schematic configuration of a transmission system using a loop network. A plurality of nodes 2 are connected to a loop-shaped transmission path 1 to constitute a transmission system for mutually transmitting and receiving data. Each of the communication nodes 2 includes a transmission line interface 21, a circulation data processing unit 22, a transmission / reception processing unit 23, and a higher-level protocol processing unit 24.

The transmission line interfaces 21a and 21b are:
The communication frame on the transmission path 1a is received and converted into a data format suitable for processing in the node 2, and the transmission data is converted into a communication frame suitable for transmission and transmitted on the transmission path 1a.
b. The circulation data processing unit 22 determines whether or not the received frame is unnecessary in the system. The transmission / reception processing unit 23 performs transmission processing of transmission data for which a transmission request has been issued from the upper-level protocol processing unit 24, reception processing of reception data to be transmitted to the upper-level protocol processing unit 24 of the own node, and reception at the own node. A transmission process of transmitting an unnecessary reception frame to a downstream node (called a repeat) is performed. The upper-layer protocol processing unit 24 processes transmission / reception data according to an upper-layer communication protocol.

FIG. 2 shows the configuration of the circulation data processing unit.
The circulating data processing unit 22 includes a circulating process identifier detecting circuit 22 for detecting a circulating process identifier added to the received data.
1; an identifier subtraction circuit 222 for updating by subtracting “1” from the value of the circulation processing identifier; an identifier determination circuit 223 for determining whether the subtraction result is “0”; and a circuit 22 for processing the circulation processing identifier. During the operation, the received data is discarded when the subtraction result of the identifier determination circuit 223 is “0” and the received data is output to the transmission / reception processing unit 23 when the subtraction result is “0”. And a received data discard processing unit 224.

Next, the operation of the communication node 2 according to the above embodiment will be described. The transmission / reception processing unit 23 that has received the transmission request from the upper-level protocol processing unit 24 configures a data format necessary for transmission, and transmits the data format to the transmission line 1b via the transmission line interface 1b.

FIG. 3 shows an outline of the data format of the transmission data. As shown in FIG. 9A, the data format 80 includes a receiving node identifier 81 representing a receiving destination, a round process identifier 83 in which a certain initial value is written, and data 84. The initial value written to the circulation processing identifier 83 is equal to or greater than the number of all nodes in the transmission system. For example, the rounding process identifier 8
In a transmission system in which 3 is 8 bits and the number of nodes in the system is allowed up to 255, the initial value may be "255" (all bits are "1") regardless of the current number of nodes.

On the other hand, the transmission line interface 21a converts the communication frame received from the transmission line 1a into a data format suitable for processing in the node 2, and outputs the data to the circulation data processing unit 22. Naturally, the data format converted from the received frame is the same as that in FIG. However, the circulation processing identifier 83 has changed from the initial value.

FIG. 4 is a flowchart showing the processing operation of the circulation data processing unit. When receiving the received data from the transmission line interface 21a (s101), the circulation data processing unit 22 updates the circulation processing identifier 83 by subtracting "1" from the value of the circulation processing identifier 83 (s102). Then, it is determined whether the value of the circulation processing identifier 83 is “0” (s1
03), if 0, discard the received data (s104),
If it is not 0, the received data is passed to the transmission / reception processing unit 23 (s
105).

When the reception node identifier 81 added to the reception data format 80 indicates its own node, the transmission / reception processing unit 23 generates data 84 from which the reception data identifier 81 and the round process identifier 83 are removed, and Output to the protocol processing unit 24. If the receiving node identifier 81 does not indicate the own node, the receiving data 80
Is output to the transmission line interface 1b as transmission data 80. The transmission line interface 1b converts the transmission data 80 into a communication frame suitable for the transmission line 1, and then converts the transmission frame
Send to

FIG. 3B shows another data format. In this data format 80, a transmission node identifier 82 is added in addition to the reception node identifier 81 and the round process identifier 83. When using the transmission data of this format, the transmission / reception processing unit 23 performs an operation of discarding the reception data 80 when the transmission node identifier 82 added to the reception data 80 indicates the own node, in addition to the above-described operation. I can do it.

Next, the overall operation of the transmission system will be described. FIG. 5 shows the flow of data in the system under normal conditions. From the node A, the receiving node identifier 81 = D, the initial value of the loop processing identifier 83 is NC = 111, and the transmission data 80 including the data 84 is subtracted by “1” from the value NC of the loop processing identifier 83 at the nodes B and C at the nodes B and C. In this case, the data is repeated while reaching the node D.

In this case, since the value of the circulation processing identifier 83 of the nodes B, C, and D is NC ≠ 0, the transmission data 80 is transmitted to the transmission / reception processing unit 23 of the node D without being discarded on the way. The transmission / reception processing unit 23 receives the reception node identifier 81
Indicates its own node D, the received data identifier 81
And the data 84 from which the circulation processing identifier 83 is removed,
Output to the upper protocol processing unit 24. Also, since the received data 80 is not repeated, it is deleted from the transmission path.

FIG. 6 shows the flow of data in the system when an error occurs. The illustrated example is the same as the case of FIG. 5, and the node D that is the destination of the transmission data 80 is down due to a failure. The transmission line of the system is equipped with, for example, an optical bypass device to bypass a down node, so that the data 80 not received by the node D goes around the transmission line 1 indefinitely as it is. .

In the present embodiment, the transmission data 80 bypassing the node D sequentially passes through the nodes 2 in the loop by repeating while decreasing the value NC of the circulation processing identifier 83 by “1”, and then passes to the node N. To reach. The circulation data processing unit 22 of the node N subtracts “1” from the value of the circulation processing identifier 83 and, when the value becomes “0”, stops the repeat of the received data and discards it. In the figure, the node N to be discarded is located before the node A that transmitted the data. However, since the initial value of the NC of the rounding process identifier 83 is usually set to be equal to or more than the number of nodes in the system, it actually indicates the node N where NC = 0 in the second or more rounds.

Next, the case where the transmission data is multicast will be described. FIG. 7 shows the flow of multicast data in a normal state. The format of the transmission data in the multicast has the configuration shown in FIG. That is, the receiving node identifier 81 (= M) common to the nodes A to N,
The transmission node identifier 82 (= S) and the circulation processing identifier 83
Is added. The transmission data 80 multicast from the node A is subtracted from the NC of the circulation processing identifier 83 by “1” at each of the nodes B, C, and N,
It returns to the source node A and is discarded. The initial value of the round processing identifier 83 is set to a value so that NC does not become “0” in the subtraction by each node in the first round of the loop.

FIG. 8 shows the flow of multicast data when an abnormality occurs. Each node is equipped with an optical bypass device, and the transmission line is bypassed when the node goes down. As shown in the figure, when the transmission source node A goes down, the transmission data 80 is not discarded by the node A, and
Orbit. However, the circulating process identifier NC is continuously subtracted, and is discarded when, for example, NC = 0 at the node B. As described above, even when the transmission source node goes down due to the multicast transmission, the transmission data does not infinitely circulate on the transmission path.

In the above description, the destination or source node 2
The method of erasing a failed frame that circulates on the transmission path without being erased when the system goes down has been described. Such a trouble frame also occurs due to garbled data of the reception node identifier and the transmission node identifier, and the present invention is also effective in such a case.

In the communication frame according to the present invention, the rounding process identifier is subtracted every time the communication frame passes through each node. Therefore, the receiving node identifier or the transmitting node identifier in the frame receives data destruction due to electromagnetic noise or the like, and the receiving node or Even when it becomes difficult for the source node to delete the frame, the node that has received the faulty frame having the rounding process identifier of 0 executes the deletion.

[Embodiment 2] Next, Embodiment 2 of the present invention
Will be described. In the first embodiment described above, an example in which transmission is performed in one frame regardless of the amount of transmission data has been described. However, when the amount of transmission data becomes large, the bandwidth of the transmission line occupied by one frame becomes long. When a faulty frame occurs, the transmission line is completely uselessly occupied until the faulty frame is erased, thereby reducing the transmission efficiency of the system.

Therefore, in the second embodiment, when a large amount of transmission data is transmitted, the data is divided and transmitted, so that the occupied bandwidth of the transmission path due to the faulty frame can be reduced. The basic configuration of the node 2 in the second embodiment is the same as that in FIG. However, the function of the transmission / reception processing unit 23 is slightly different.

FIG. 9 shows a format of transmission data in the second embodiment. The transmission / reception processing unit 23 of the node 2 divides the transmission data 80 for which the transmission request has been issued from the higher-level protocol control unit 24 into appropriate lengths as shown in 80-1 to 80-3 in the drawing, and , A receiving node identifier 81, a loop processing identifier 83, and a division order identifier 84
Initialize. The identifiers 81 and 83 are common to each divided data and are set in the same manner as in the first embodiment. The division order identifier 84 indicates each division order, and is set to a value that can be recognized at the beginning and end. Each of the divided data is continuously transmitted via the transmission path interface 21b in the order of the division order.

FIG. 10 shows a data flow of the system according to the second embodiment. Node A receives the receiving node identifier 81
Transmits the divided data 80-1 to 80-3 of D in the order of the division order identifier 84. Each divided data 80-
1 to 80-3 pass through the nodes B and C while subtracting "1" from the NC of the circulation processing identifier 83, and reach the node D one after another.

The transmission / reception processing unit 23 of the node D receives all the divided data addressed to the own node, reconfigures the data into one, and then passes the data to the upper-level protocol control unit 24. At this time, the division order identifier 84 of each divided data is checked, and if all the data cannot be received, the data is discarded. For the divided data not addressed to the own node, the NC of the circulation processing identifier 83 is subtracted by “1”.
Repeat to the downstream node with the divided data. If N
If C = 0, the repeat of the divided data is stopped and erased from the transmission path 1.

For example, it is assumed that node A transmits transmission data by dividing it into ten, and a noise failure occurs in a transmission line during transmission, and the value of reception node identifier 81 of the two divided data is destroyed. At this time, the eight divided data are received by the node D and erased from the transmission line, and only the remaining two data circulate on the transmission line up to the node N where NC = 0. Therefore, compared to the case where the original data that is not divided is converted into a faulty frame, the band that wastefully occupies the transmission path is reduced to one fifth, and the communication efficiency of the transmission path can be improved.

[Third Embodiment] Next, a third embodiment in which the failed frame erasing method of the present invention is applied to a transmission system employing the ATM transmission method will be described. The functional configurations of the transmission system and the nodes are the same as those in FIG. As an example of the device configuration, a PMC-Si
PM534, erra's ATM network LSI
And the transmission / reception processing unit 23 uses MB86689 and MB8668, which are LSIs for Fujitsu's ATM network.
0, MB86687, etc., using a general personal computer or workstation as the upper-level protocol processing unit 24, and adding the circuit of the circulating data processing unit 22, a clock circuit, a microprocessor, a memory, and other peripheral analog circuits based on them. This can be achieved by performing

FIG. 11 shows a cell configuration based on the ATM transmission system. In the ATM transmission system, data is mounted on a fixed-length packet 851 called a cell and transmitted on a transmission path. The cell 851 includes a cell header 810 that describes information on a receiving node and the like, and a payload 820 that carries data. The cell header 810 includes a virtual path identifier VPI and a virtual channel identifier VCI. Incidentally, the cell 851 has 53 octets, and the cell header 81
0 is 5 octets, VPI is 1 octet, VCI is 2
Octet length.

In this embodiment, the transmission / reception processing unit 2 of each node 2
3 mounts data according to a transmission request from the higher-level protocol processing unit 24 in the payload 800, and
Is used to set the same rounding process identifier 83 as described above. Also, the receiving node identifier 81 is set using the VCI. However, in the case of multicast, the receiving node identifier 81 and the transmitting node identifier 82 are set using the VCI.

As a result, each node 2 can operate in the same manner as in the first or second embodiment. For example, at the time of single cast, when the VCI of the data received from the transmission path 1 is addressed to itself,
Is extracted and passed to the upper-level protocol processing unit 24, and the received data is not repeated. When the VCI of the received data is not addressed to itself, the NC of the loop processing identifier 83 of the VPI is decremented by "1". When NC = 0, no repetition is performed. When NC ≠ 0, the repetition is performed to the downstream node.

As described above, according to the present embodiment, even in a data transmission format called a cell of the ATM transmission system applied to a loop type network, a faulty frame that goes around infinitely can be reliably erased with a simple configuration. It is needless to say that also in the present embodiment, the divided data method of the second embodiment can be adopted.

Fourth Embodiment In the first to third embodiments, the description has been made by applying the present invention to a network in which the transmission path is a loop. However, the present invention can also be applied to a non-loop-type network. Hereinafter, a fourth embodiment in which the transmission path is applied to a transmission system other than a loop shape will be described.

FIG. 12 shows a configuration of a node used in a mesh-shaped or tree-shaped network. Node 3
A plurality of transmission paths 111 to 113 are connected, for example, transmission path 1
It also functions as a switching device, such as transmitting data received from the transmission line 11a to the transmission line 111b in the same direction, switching the transmission direction, and transmitting the data to the transmission line 112b or 1113b.

The relay node 3 transmits the transmission path interfaces 211a, b to 213a,
b and a data discard processing unit 292, respectively, and a common transmission / reception processing unit 230 and a higher-level protocol processing unit 240. The transmission line interfaces 211 to 213 and the data discard processing unit 292 have the same functions as the transmission line interface 111 and the round data processing unit 22 in FIG. The transmission / reception processing unit 230 has a function of identifying to which transmission path the reception data is to be transmitted based on the reception node identifier 81 of FIG. 3 or 11 and performing a relay process in addition to the function of the transmission / reception processing unit 23 of FIG. have. This relay function can be realized using, for example, the ATM network LSI described in the third embodiment.

FIG. 13 shows a configuration of a transmission system using a mesh network. Node 3 of this transmission system
Has the relay function of FIG. Nodes 3-1 to 3
-6 is a transmission line 111 for connecting each in a loop, and a transmission line 112 for directly connecting the nodes 3-2 and 3-4.
And a transmission line 113 that directly connects the nodes 3-4 and 3-6 constitute a mesh network.

In this network, closed loops such as A, B, and C are formed by various relays by switching of each node 3. Therefore, there is a possibility that a failure frame generated due to a node failure or the like circulates in a closed loop. However, when the data discarding processing unit 292 of the node 3 subtracts “1” from the NC of the circulation processing identifier 83 of the received data to make NC = 0, the data discarding unit 292 discards the received data even if it is not addressed to itself. The frame can be prevented from going around indefinitely.

FIG. 14 shows a transmission system using a tree network and the flow of data. Now, node 3-1
When transmitting data to the higher-level device 28 (for example, a control computer) of the node 3-8 from the transmission node 111, the transmission node 111 adds the receiving node identifier 81 and the round process identifier 83 in FIG. At this time, if a failure occurs in the relay function of the node 2 and the data is transmitted to the transmission path 112 instead of the original transmission path 113, the transmission data is transmitted in a tree-shaped transmission path 113, 114, 115, 116,. . . There is a possibility that it will propagate and stray.

However, the data discard processing unit 292 of each node 3 in the present system subtracts "1" from the NC of the rounding process identifier 83 of the relayed data to make NC = 0 (in the figure, node 3-5). , 3-6), the received data is discarded, so that the occupation of the network bandwidth due to the stray transmission data can be prevented.

Note that the transmission method based on the divided data of the second embodiment can be applied to the transmission data in the fourth embodiment. In the present embodiment, for the sake of convenience, the same name of the “circular processing identifier” as in the case of the loop shape is used,
It is more appropriate to use a “passing node identifier”.

Also, in all the embodiments described above, a predetermined initial value is set to the loop processing identifier of each node, and “1” is subtracted every time the communication frame passes through the node, and the value of the identifier is changed. A method of discarding at the node that has become “0” is adopted. However, on the contrary, the initial value is 0
As a method, "1" is added each time the data passes through the node, and when the value of the identifier exceeds the threshold, discarding may be performed.

[0059]

According to the present invention, the communication frame is provided with an identifier indicating the number of passed nodes, and each node on the transmission line updates the identifier before repeating the communication frame not addressed to itself, so that the number of passed frames becomes a predetermined number. Stop repeating the number of frames reached. Therefore, a failure frame that may go around or stray on the transmission path due to the down of the corresponding node in the destination erasure or the transmission source erasure, or the destruction of the data of the destination or the transmission source of the communication frame due to noise or the like on the transmission path. Thus, the data can be reliably erased by the predetermined number of nodes, and the communication efficiency of the transmission system can be improved.

When the data amount is large, the communication frame is divided into a predetermined length and transmitted, the identifier indicating the number of passages is updated for each divided frame, and the repetition of the divided frame having reached the predetermined number is stopped. Therefore, it is possible to avoid occupation of the transmission path band by a long trouble frame, so that communication efficiency and functionality of the system can be improved.

Further, since the present invention can be applied to a wide range of networks regardless of the loop shape or non-loop shape and has no restrictions on the system configuration such as providing monitoring nodes and fixing the order of nodes, the transmission system is flexible and easy to use. Can be provided.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a transmission system and a node according to an embodiment of the present invention.

FIG. 2 is a functional block diagram according to an embodiment of a circulation data processing unit.

FIG. 3 is an explanatory diagram showing a data format of transmission data according to the first embodiment.

FIG. 4 is a flowchart illustrating a reception operation of the transmission / reception unit according to the first embodiment.

FIG. 5 is an explanatory diagram showing a single-cast data flow in a normal state according to the first embodiment;

FIG. 6 is an explanatory diagram showing a single-cast data flow at the time of abnormality according to the first embodiment;

FIG. 7 is an explanatory diagram showing a flow of multicast data in a normal state according to the first embodiment;

FIG. 8 is an explanatory diagram showing a flow of multicast data at the time of abnormality according to the first embodiment;

FIG. 9 is an explanatory diagram showing a data format of transmission division data according to the second embodiment.

FIG. 10 is an explanatory diagram showing a flow of transmission division data according to the second embodiment.

FIG. 11 is an explanatory diagram showing a cell configuration of a transmission system to which an ATM transmission system according to a third embodiment is applied.

FIG. 12 is a configuration diagram of a node used in the non-loop network according to the fourth embodiment.

FIG. 13 is a configuration diagram of a transmission system of a mesh network according to a fourth embodiment.

FIG. 14 is an explanatory diagram showing a tree-shaped network transmission system and data flow according to a fourth embodiment.

[Explanation of symbols]

1, 111 to 113: transmission line, 2, 3: node, 21,
Reference numerals 211 to 213: transmission line interface, 22: loop data processing unit, 220: delay register, 221: loop processing identifier detection circuit, 222: identifier subtraction circuit, 223: identifier determination circuit, 224: reception data discard processing unit, 23,
230: transmission / reception processing unit, 24, 240: upper-level protocol processing unit, 292: data discard processing unit, 8, 80: transmission data, 81: reception node identifier, 82: transmission node identifier, 83: circulation processing identifier, 84: data , 800 cells, 810 cell headers.

Claims (10)

[Claims] 1. A communication method for a transmission system in which a plurality of nodes are coupled to a transmission path and mutually transmit and receive data via the transmission path, wherein a transmission source node includes a communication frame mounting data to be transmitted. A node passing identifier reflecting the number of nodes passed along with the receiving node identifier is assigned. Each node on the transmission path, if the received communication frame is not addressed to itself, repeats the node before repeating the communication frame on the transmission path. A communication method for a transmission system, comprising: updating a value of a pass identifier; and stopping the repeat when it is determined from the value that the number of passed nodes has reached a predetermined number. 2. The predetermined number according to claim 1, wherein the predetermined number is set to a value exceeding the total number of nodes from the transmission source node to the reception destination node via the transmission path and set to the reception node identifier. A communication method for a transmission system, comprising: 3. The transmission node according to claim 1, wherein when the transmission source node multicasts to each node on the transmission path, a transmission node identifier is added to the communication frame to enable transmission source erasure and transmit. A communication method for a transmission system, wherein the predetermined number is set to a value that exceeds a total number of nodes on a transmission path until a communication frame returns to the transmission source. 4. The node passing identifier according to claim 1, 2 or 3, wherein the node passing identifier is initially set to 0 and 1 is added each time a node passes, or the predetermined number is initially set and passed each time a node passes. A communication method for a transmission system, wherein 1 is subtracted. 5. The communication method according to claim 1, wherein the communication method of the transmission system includes an asynchronous transfer mode (AT).
M) When the transmission method is applied, the communication frame is read as a cell, and a virtual path identifier (VPI) in a cell header is read.
A communication method for a transmission system, comprising: assigning the node passing identifier to a virtual channel identifier (VCI) in a single cast, or the receiving node identifier and a transmitting node identifier in a multicast. 6. The communication node according to claim 1, wherein the transmission source node divides the data to be transmitted at one time into a plurality of pieces and transmits each piece of the divided data. To the receiving node identifier, the node passing identifier, and a division order identifier indicating the division order of the data, and sequentially and continuously transmit, each of the nodes on the transmission path receives a communication frame addressed to itself. In the case, based on the division order of the division order identifier,
When receiving all the divided data, a predetermined reception process is performed.
Otherwise, discard the received split data,
If the received communication frame is not addressed to itself, update the value of the node passage identifier before repeating the communication frame on the transmission path, and from the value, the node passage number reaches a predetermined number set in advance. A communication method for a transmission system, wherein the repeat is stopped when it is determined that the communication is performed. 7. In a transmission system in which a plurality of nodes are coupled to a transmission path and mutually transmit and receive data via the transmission path, the node includes a node together with a reception node identifier in a communication frame mounting data to be transmitted. Performs transmission processing including the assignment of a node passage identifier reflecting the number of passages, while performing reception processing when the received communication frame is addressed to itself,
Also, transmission / reception processing means for performing transmission processing for repeating the communication frame to the transmission path when the communication frame is not addressed to itself, updating the value of the node passage identifier of the received communication frame, and determining the node passage number from the value in advance. A transmission system comprising a faulty frame discarding means for stopping the repeat when it is determined that the number has reached a set predetermined number. 8. The transmission system according to claim 7, wherein when the transmission path has a loop shape, the predetermined number is a value exceeding the total number of nodes coupled to the transmission path. 9. The communication device according to claim 7, wherein when the transmission path has a non-loop shape such as a mesh shape or a tree shape, the node includes a plurality of transmission line interfaces connected to a plurality of transmission lines having the same or different communication directions. Further, the transmission / reception processing means has a relay function of passing the communication frame to a transmission line interface in a communication direction corresponding to the receiving node identifier when the received communication frame is not addressed to itself. 10. A transmission system in which a plurality of nodes are coupled to a transmission line on which data transmission is performed according to an asynchronous transfer mode (ATM) transmission method, and cells are mutually transmitted and received. A transmission path interface for transmitting and receiving the cell, and a data transmission path mounted on the payload of the cell, and a receiving node identifier for a virtual channel identifier of the cell, and a node passing identifier reflecting the number of passed nodes for a virtual path identifier, respectively. Transmission processing means for adding and outputting to the transmission path interface, performing a predetermined reception processing when the reception node identifier of the cell received by the transmission path interface is addressed to itself, and when the received cell is not addressed to itself. Reception processing means for passing the data to the transmission processing means for repeating the transmission processing means; Updates the value of the child +1 or -1 to the transmission system whose value is characterized in that it comprises a fault cell discarding means for stopping the repeat when it reaches a predetermined value.