JP3494536B2 - Broadcast fixed-length cell disassembler - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a broadcast fixed-length cell disassembling device, and more particularly to a communication device of a node of a network when performing connectionless broadcast communication in an ATM (asynchronous transfer mode) communication network. The present invention relates to a broadcast fixed-length cell disassembly device suitable for use.

[0002]

2. Description of the Related Art In recent years, B-ISDN capable of transmitting various media information including voice, data, and images has been put into practical use by digitizing and integrating a communication network. this
For example, an ATM (Asynchronous Transfer Mode) communication method is known as one means for realizing B-ISDN. ATM communication system is
This is a method in which various media information is divided into fixed length cells called ATM cells and exchanged and transmitted in units of these cells. By adopting this communication method, it is possible to unify networks and build a network that does not depend on various media.

For example, in a B-ISDN network, an ATM cell consists of a 48-byte information field and a 5-byte header. The header is a virtual path that is set between the ground according to the amount of information
Virtual path identifier (VPI) that identifies the (VP), a virtual channel identifier (VCI) that identifies the virtual channel (VC) that is set for each ground of the information as multiple lines in the virtual path, and the type of information field , A payload type (PT) indicating cell priority, a cell loss priority indication (CLP) indicating cell priority, and a header error control code (HEC) for detecting header error and cell synchronization. In this case, 8 bits (256 ways) are allocated to the virtual path identifier (VPI) on the terminal side and 12 bits are allocated to the network side so that a maximum of 4096 virtual paths can be supported. 16 bits are allocated to the virtual channel identifier (VCI), and it is possible to support up to 65536 lines.

By the way, connection methods between terminals in an ATM communication network are classified into connection type and connectionless type. In connection-type communication, for example, a dial number is turned, the sending side and the receiving side are confirmed before communication is started, a communication line is set up, and then communication is performed. On the other hand, in the case of connectionless communication, the information sent by the sending side is packetized, the destination is added to each and sent to the network side, and the network side confirms the destination for each packet and sends it to the receiving side. is there.

Here, as a connectionless communication system, for example, a communication device of a certain node accommodates a plurality of terminals and a communication device of a plurality of other nodes, and the communication devices of the plurality of other nodes are also connected. At the same time, consider a network in which the communication devices of the other nodes also accommodate one or more terminals, and the communication devices are connected in a mesh.

In the connectionless communication of such a network, the communication device of each node adds a destination address to each incoming ATM cell and performs a connection process (routing process) based on the destination address. In addition, when performing broadcast communication, the communication device of each node adds a dedicated address (broadcast address) to the destination address of each incoming ATM cell, for example, to the unused bit part of the VPI, and The message is routed to each individual destination address indicated by the broadcast address. The routing processing information in this case, that is, the broadcast address and the individual destination address indicated by the broadcast address are accumulated in the storage device (broadcast address table) in the communication device.

Next, in the above network, a conventional copying (reproducing) method in the case where a communication device of a node having the above-mentioned function performs a broadcast communication using an ATM cell whose destination address is a broadcast-only address. Will be described below.

The communication device of each node has means for discriminating whether the source of the received ATM cell is from the terminal accommodated in the own node or from another node, and this means is self-contained. When it is determined that the communication is from the terminal of the node, the communication device of the own node accommodates the own node from the subscriber information of each subscriber that composes the broadcast group stored in the storage device of this device. Individually duplicated ATM cells are sent to subscriber terminals in the broadcast group, and for subscriber terminals in the broadcast group accommodated by other nodes, they are individually transmitted to the communication devices of other nodes accommodating those terminals. AT duplicated on
Send M cells. When it is judged that it is from another node, the individually duplicated ATM cell is sent only to the subscriber terminals of the broadcast group accommodated by the own node.

Further, the ATM cell transmitted by the own node is screened at the output stage of the communication device of the node so as not to be transmitted to the subscriber who transmitted the ATM cell. .

[0010]

However, in the conventional technique for preventing the duplicated ATM cell from being transmitted to the subscriber who originates the ATM cell by screening the communication device of the originating node as described above, There was a problem that the registration data for screening became huge. In other words, it was necessary to devise so that the registered data for screening would not become huge.

The present invention solves the above-mentioned drawbacks of the prior art and makes it possible to prevent a duplicate ATM cell from being transmitted to a subscriber who originates an ATM cell by a simple circuit system. The purpose is to provide a device.

[0012]

In order to solve the above problems, the present invention provides a broadcast address for identifying a broadcast terminal group,
From the terminal that own node accommodates a broadcast fixed-length cell with a message added to the header that contains the virtual path identification address that identifies itself or another node and the virtual channel identification address that identifies the terminal accommodated by itself or another node In the broadcast fixed-length cell disassembling device of connectionless communication that receives and analyzes the routing bit of the header and sends the copied broadcast fixed-length cell to the broadcast terminal group indicated by the broadcast address, The broadcast address to which the terminal accommodated in the node belongs is accommodated, the address identifying the own node is accommodated in the virtual path identification address area, and the terminal accommodated in the own node is identified in the virtual channel identification address area. Address is accommodated, the broadcast fixed-length cell is received from the terminal accommodated by the own node, and the received broadcast fixed-length cell is output and received. Filter means and filter means for separating and outputting the broadcast address, virtual path identification address and virtual channel identification address of the broadcast fixed length cell and separating and outputting the received broadcast fixed length cell broadcast address Broadcast address registration means for receiving a broadcast address from the broadcast address and outputting an entry address corresponding to this broadcast address, a broadcast address of a broadcast group to which each terminal accommodated in the own node belongs, and this broadcast group The virtual path identification address and virtual channel identification address of each terminal are accumulated,
First storage means for reading out each of the accumulated addresses corresponding to the entry addresses from the broadcast address registration means, and an entry address from the broadcast address registration means, and each terminal of the broadcast addresses based on this entry address. The copy control information means for outputting the write and read addresses as many as the number of the same, the broadcast fixed length cells from the filter means, the write and read addresses from the copy control information means, and the broadcast fixed length cells of the broadcast fixed length cells based on these addresses. Buffer means for accumulating and reading and duplicating the message, receiving the duplicated message from the buffer means, receiving a broadcast address, a virtual path identification address and a virtual channel identification address from the first storage means, and receiving the received message and each address. Duplicate and duplicate at a specified position The route information giving means for outputting the fixed length cell and the broadcast address, the virtual path identification address and the virtual channel identification address from the filter means and the first storage means are compared with each other. To the route information comparison means that outputs a discard control signal and outputs a passage control signal if different, and receives a duplicate broadcast fixed-length cell from the route information adding means, and discards or passes the route information comparison means. Transmission data control means for receiving a control signal, discarding the received duplicate broadcast fixed length cell when receiving the discard control signal, and passing the received duplicate broadcast fixed length cell when receiving the passage control signal And a broadcast address accommodating a broadcast address to which a terminal accommodated in the same self-node belongs from both the filter means and the first storage means, and an address identifying the self-node. If the virtual channel identifier address address for identifying the terminal accommodated in the virtual path identification address and the own node-less is housed is housed is sent to the route information comparing means,
This route information comparing means is characterized in that it outputs a discard control signal.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Next, an embodiment of a broadcast communication system according to the present invention will be described in detail with reference to the accompanying drawings.

FIG. 2 shows an embodiment of a communication device including a broadcast ATM cell disassembling unit to which the broadcast communication system according to the present invention is applied, and FIG. 3 applies the communication device of FIG. An example of a connectionless ATM communication system is shown. In the example of FIG. 3, there are terminals 12, 14, 23, 32, 34, 42 1
It consists of two broadcast groups, and this broadcast group will be explained as an example. Further, only the portions directly related to the present embodiment are shown in these drawings, and the portions not directly related to the present embodiment are not shown.

The ATM communication system shown in FIG. 3, which is effectively applied to the nodes 10, 20, 30, and 40 of the ATM network, has a 48-byte message (information) sent from the terminal 12, for example.
When the node 10 receives a fixed-length broadcast ATM cell with a header including 5 bytes of broadcast information, the node 10 duplicates the received ATM cell and performs routing processing, and based on the broadcast information. A terminal 14 accommodated by the own node 10, a terminal 23 accommodated by another node 20, and a terminal 3 accommodated by another node 30
Replicated ATM for terminals 2 and 34 and terminal 42 accommodated by other node 40
The cell is sent so that the duplicated ATM cell is not sent to the source terminal 12 accommodated in the own node 10.

Referring to FIG. 3, the node 10 connects the terminal 12 via the intra-network signal line (virtual channel VC) 16 and the intra-network signal line 18
Terminal 14 via the inter-network signal line (virtual path VP) 50, the node 30 via the inter-network signal line 52, and the node 40 via the inter-network signal line 54. And are connected respectively. The node 20 connects the terminal 22 via the intra-network signal line 26, the terminal 23 via the intra-network signal line 27, and the intra-network signal line 28.
Each of the terminals 24 is accommodated via the inter-network signal line 56, and is further connected to the node 30 via the inter-network signal line 56 and the node 40 via the inter-network signal line 58. Further, the node 30 accommodates the terminal 32 via the intra-network signal line 36, the terminal 34 via the intra-network signal line 38, and the inter-network signal line 59.
And the nodes 40, respectively. The node 40 accommodates the terminal 42 via the intra-network signal line 46, the terminal 43 via the intra-network signal line 47, and the terminal 44 via the intra-network signal line 48. As can be seen from the figure, the nodes are connected in a mesh in this example.

The respective nodes 10, 20, 30 and 40 are connected by a virtual path VP having a predetermined capacity set in a physical transmission line as shown in FIG. 3, and set in these virtual paths VP. Communication devices 10, 20, 30, 40 for routing ATM cells via a plurality of virtual channels VC and transferring them to respective routes.

In this embodiment, the ATM cell transferred between the node and the terminal and between the nodes includes a 5-byte ATM header portion 500 and a 48-byte payload portion 600 as shown in FIG. It is information formed into a fixed length of 53 bytes. The header part 500 includes a virtual path identifier (VPI) 502, a virtual channel identifier (VCI) 504, and a payload type (PT) 50.
6, a cell loss priority indicator (CLP) 508, and a header error control code (HEC) 510. Payload part 600 is 48 from the terminal
Byte user information.

In this embodiment, whether the information sent to the upper 8 bits of the virtual path identifier (VPI) 502 is from the terminal accommodated in the own node or from another node. Information (virtual path identification adrel VP), that is, information for identifying the own node and other nodes is inserted, and the lower 4-bit portion is broadcast information (broadcast information for identifying multiple broadcast groups). Address) is inserted, and also
The 16-bit portion of the virtual channel identifier (VCI) 504 is the information (virtual channel identification address VC) for identifying the line accommodated in each node, that is, the information of the transmitting terminal that transmits the information or the receiving terminal that receives the information. Information is inserted. The insertion position of each of the information of the broadcast address, the virtual path identification address VP and the virtual channel identification address VC is in the area of the identifier (VPI) 502 and the identifier (VCI) 504, or the header error control code of the ATM header section 500 ( It may be anywhere within the area excluding HEC) 510, and the number of bits of each of these may be set appropriately according to the system.

The payload type 506 is a 3-bit code indicating the type of the information field 600 such as user information or control information. The cell loss type priority display 508 is a 1-bit code indicating the priority of each cell. When the value is set to "1", the cell has a low priority, and when the value is set to "0", the cell is a priority cell. The header error control code (HEC) 510 is a 1-byte code used for error detection of the 4-byte header and cell synchronization.

The nodes 10, 20, 30, 40 of this embodiment shown in FIG.
In detail, nodes 10, 20, 30, and 40 are broadcast ATM cell disassembling unit 200, ATM switch 300, and ATM cell assembling unit.
It consists of 400. Details of the broadcast ATM cell disassembling unit 200 of FIG. 2 to which the broadcast communication system according to the present invention is applied are shown in the functional block diagram of FIG.

The broadcast ATM cell disassembling unit 200 separates the header unit 500 from a broadcast ATM cell having a fixed bit length received from its own node or another node, and based on the broadcast address, a virtual path identification address VP and a virtual channel. It is a broadcast header separation processing unit that analyzes a routing bit composed of an identification address VC. In particular, in this embodiment, when receiving a broadcast ATM cell from a terminal accommodated in the own node, the broadcast of this own node is received.
ATM cell disassembling unit 200 receives virtual path identification address VP and virtual channel identification address VC and virtual address identifying address VP and virtual channel identification address stored in cell disassembling unit 200 based on the received broadcast address. If it is the same, the duplicate ATM cell is discarded and the transfer to the calling terminal is stopped, and if it is different, the duplicate ATM cell is passed and transferred to a terminal other than the calling terminal. It is a header analysis unit.

Specifically, as shown in FIG. 1, the cell disassembling unit 200 includes a route information filter 60, an address filter 62,
A copy buffer 64, a route information addition circuit 68, a transmission data control circuit 70, a relay route information registration table 72, a broadcast address registration CAM (Content Addressable Memory) 74,
Copy control information memory 76 and relay route registration memory 78
, Subscriber route registration memory 80, and copy control circuit 82
And a data selector 84 and a route information comparator 86. Although not shown in FIG. 1, the input 102 of the cell disassembling unit 200 is subjected to the processing via a circuit for establishing error correction and cell synchronization of the header unit 500 based on the header error control code 510. ATM cells are supplied to.

In FIG. 1, for example, the terminal 1 shown in FIG.
Of the broadcast group consisting of 2, 14, 23, 32, 34, 42, terminal 12 broadcasts A
When transmitting a TM cell, 6 broadcast ATM cells are input.
Sent to. In detail, depending on the terminal 12, the terminals 12, 14, 2
Virtual path identification address V for broadcast address for 3, 32, 34, 42
Broadcast ATM cells having a header with P being "00" and a virtual channel identification address VC being "16" are terminals 12, 14, 23, 32, 34, 4
Generated in sequence and sent to input 102. In this example, “00” is the virtual path identification address for the accommodation terminal of the node 10 itself.

In addition, for example, the terminal 23 in the broadcast group broadcasts AT to the node 10 via the node 20 and the network signal line 50.
When transmitting M cells, two broadcast ATM cells are input 102
Sent to. Specifically, one of the nodes 20, which has received the broadcast ATM cell from the terminal 23, is to add the virtual path identification address VP “50” and the virtual channel identification address VC “16” to the broadcast address for one of the terminals 12. One of the broadcast ATM cells having the header that has been set is the broadcast address for the terminal 14; the virtual path identification address VP is "50" and the virtual channel identification address VC is "18".
Broadcast ATM cells with headers added to are sequentially generated and sent to input 102.

The route information filter 60 is composed of, for example, a 1-input multi-output demultiplexer which selectively and sequentially outputs in accordance with the number of bits, and outputs the broadcast ATM cell input to the input 102 to the output 104. Separates and outputs the virtual path identification address VP of the broadcast ATM cell input to input 102
This is a data separation circuit that separates the broadcast address, virtual path identification address VP, and virtual channel identification address VC of the broadcast ATM cell input to 106 and input 102, that is, route information, and outputs it to output 108. The output 104 is connected to the address filter 62, the output 106 is connected to the relay route information registration table 72, and the output 108 is connected to the route information comparator 86.

The address filter 62 is also the route information filter 60.
Similar to the above, it consists of a 1-input multi-output demultiplexer and outputs the broadcast ATM cell input to input 104 to output 110 and separates the broadcast address of the broadcast ATM cell input to input 104 and outputs it. A data separation circuit for outputting to 112. Output 110 is connected to copy buffer 64 and output
112 is connected to the broadcast address registration CAM 74.

The copy buffer 64 is a buffer for temporarily storing 48 bytes of user data of the payload section 600 of the broadcast ATM cell input to the input 110, and has a capacity of 48 bits or more. The duplicated data read from the buffer is output at output 114. A control signal for writing data in the buffer and a control signal for reading data from the buffer are supplied from the copy control circuit 82 via the control line 116.

The route information adding circuit 68 is provided in the copy buffer 64.
A circuit that adds the route information consisting of the broadcast address, the virtual path identification address VP, and the virtual channel identification address VC input from the input 120 to the 48-byte user data duplicated in the input 114 and outputs it to the output 118. is there. input
120 is connected to the output of the data selector 84 and the input of the route information comparator 86, and the output 118 is connected to the transmission data control circuit 70.

When the data input to the input 118 is sent from the transmitting terminal of its own node, the transmission data control circuit 70 inputs a control signal indicating discard to the input 124 and discards the data. , If the data entered in input 118 is not from the originating terminal of the local node, input 12
Control signal indicating passage is input to 4 and its data is output
This is the circuit that is output to 122. The input 124 is connected to the route information comparator 86, and the output 122 is the ATM switch 30 shown in FIG.
Connected with 0.

On the other hand, in the relay route information registration table 72, the route assigned for relay is registered in, for example, a ROM, and the virtual path identification address VP input to the input 106 is input to the ROM so that the own node It is determined whether it is from the terminal that accommodates it or whether it is for relay, that is, from another node, and outputs a logic level "1" for its own node and a logic level "0" for relay 126 Is a determination circuit for outputting to. The output 126 is connected to the corresponding control input terminal of the data selector 84.

The broadcast address registration CAM 74 is a table in which entry addresses corresponding to the broadcast addresses are registered in, for example, a ROM, and the entry addresses corresponding to the broadcast addresses input to the input 112 are output to the output 128. The output 128 is connected to the corresponding inputs of the copy control information memory 76, the relay route registration memory 78 and the subscriber route registration memory 80, respectively.

The copy control information memory 76 stores information indicating the number of copies corresponding to the entry address in, for example, a ROM.
It is a table registered in, for example, and outputs information indicating the number of copies according to the entry address input from the input 128 to the output 130. The output 130 is connected to the copy control circuit 82. Specifically, when the terminal 12 of the broadcast group transmits a broadcast ATM cell to the node 10, the copy control information memory 76 of the node 10 outputs information indicating the number of copies of six sheets, and When the terminal 23 of the broadcast group transmits a broadcast ATM cell to the node 10 via the node 20 and the inter-network signal line 50, it outputs information indicating the number of two copies.

The relay route registration memory 78 stores a broadcast address, a virtual path identification address VP and a virtual channel identification address corresponding to the entry address based on the broadcast ATM cell from the subscriber (terminal) accommodated in another node. This is a table in which route information composed of VC is registered in, for example, a ROM, and the route information corresponding to the entry address input from the input 128 is output to the output 132. The output 132 is connected to the corresponding data input terminal of the data selector 84.

Specifically, the terminal 23 in the broadcast group is broadcast to the node 10 via the node 20 and the inter-network signal line 50.
When sending a cell, the relay route registration memory of node 10
78 is a broadcast address of this broadcast group for the terminal 12, and the virtual path identification address VP is "00" and the virtual channel identification address.
The VC outputs the information of "16", and outputs the broadcast address of this broadcast group for the terminal 14, the information of the virtual path identification address VP of "00" and the virtual channel identification address VC of "18".

The subscriber route registration memory 80 stores the broadcast address, the virtual path identification address VP and the virtual channel identification address VC corresponding to the entry address based on the broadcast ATM cell from the subscriber accommodated in the own node. This is a table in which the route information is registered in, for example, a ROM.
The route information corresponding to the entry address input from 128 is output to output 134. The output 134 is connected to the corresponding data input terminal of the data selector 84.

Specifically, when the terminal 12 of the broadcast group transmits a broadcast ATM cell to the node 10, the subscriber route registration memory 80 of the node 10 is used for the terminal 12 as the broadcast group. , The virtual path identification address VP is "00", and the virtual channel identification address VC is "16".
The broadcast address of this broadcast group and the information of the virtual path identification address VP of "00" and the virtual channel identification address VC of "18" are output for use as the broadcast address of this broadcast group for the terminal 23. , The information of virtual path identification address VP is "50" and virtual channel identification address VC is "27", and the broadcast address of this broadcast group and the virtual path identification address VP are "52" for the terminal 32. The virtual channel identification address VC outputs information of "36", and the broadcast address of this broadcast group for the terminal 34 and the virtual channel identification address of the virtual path identification address VP of "52".
The VC outputs the information of "38", the broadcast address of this broadcast group for the terminal 42, the information of the virtual path identification address VP of "54" and the virtual channel identification address VC of "46".

The copy control circuit 82 receives an address filter based on the information indicating the number of copies input from the input 130.
Outputs control signal for writing 48 bytes of user data of payload section 600 of broadcast ATM cell from 62 to buffer 64 and control signal for reading data from buffer 64.
116 The output 116 is connected to the input 116 of the buffer 64 as previously mentioned.

The data selector 84 receives the data input terminal 134 when the logic level "1" is input to the control input terminal 126.
Is turned on between the data input terminal 132 and the data output terminal 120, and between the data input terminal 132 and the data output terminal 120 is turned off. Also, when the logic level "0" is input to the control input terminal 126, the data input "ON" between terminal 132 and data output terminal 120
And data input terminal 134 and data output terminal
This is a switch circuit that turns off 120 seconds. Therefore, when the logic level "1" is input to the control input terminal 126, the route data from the subscriber route registration memory 80 is input, and when the logic level "0" is input to the control input terminal 126. The route data from the relay route registration memory 78 is output from the data output terminal 120. The data output terminal 120 is connected to the route information giving circuit 68 and the route information comparator 86.

The route information comparator 86 receives the route information consisting of the broadcast address from the route information filter 60 inputted from the input 108, the virtual path identification address VP and the virtual channel identification address VC and the data inputted from the input 120. The broadcast address from the selector 84, the route information consisting of the virtual path identification address VP and the virtual channel identification address VC are respectively compared, and if they are the same, a control signal indicating discard is sent. This is a comparison circuit that outputs to the output 124. The output 124 is connected to the input 124 of the transmission data control circuit 70, as mentioned earlier.

Specifically, the terminal 23 of the broadcast group is broadcast to the node 10 via the node 20 and the inter-network signal line 50.
When a cell is transmitted, the route information filter 60 first inputs the broadcast address and the virtual path identification address VP for the terminal 12 to the input 108 of the route information comparator 86 and the virtual channel identification address is 50. Information of VC "16" is supplied, and the broadcast address for the terminal 12 from the relay route registration memory 78, the virtual path identification address VP "00" and the virtual channel identification address VC are supplied to the input 120. The information "16" is supplied and compared by the comparator 86. In this case, since the virtual path identification addresses are different, the comparator 86 outputs a control signal indicating passage.

Subsequently, the input 108 is supplied with the broadcast address, the virtual path identification address VP of "50" and the virtual channel identification address VC of "18" for the terminal 14, and is also input.
In the 120, the broadcast address and the virtual path identification address VP are “00” and the virtual channel identification address VC is “18” for the terminal 14.
Is supplied and compared by the comparator 86. Also in this case, since the virtual path identification address VP is different, the comparator 86 outputs a control signal indicating passage.

Further, for example, when the terminal 12 in the broadcast group transmits a broadcast ATM cell to the node 10, the route information filter 86 is first input to the route information comparator 86 of the node 10.
60 supplies information of the broadcast address and virtual path identification address VP of "00" and the virtual channel identification address VC of "16" for the terminal 12, and joins the input 120 of the route information comparator 86. Information of the broadcast address and the virtual path identification address VP of "00" and the virtual channel identification address VC of "16" is supplied from the personal system route registration memory 80 for the terminal 12 and compared by the comparator 86. Since the case information is the same, the control signal indicating discard is output from the comparator 86.

Next, at the input 108, a terminal for the terminal 14 is used.
Broadcast address and virtual path identification address VP as in 12
Is supplied as "00" and the virtual channel identification address VC is "16", and the broadcast address and the virtual path identification address VP for the terminal 14 are "00" and the virtual channel identification address VC is supplied to the input 120. Is supplied and compared by the comparator 86. In this case, since the information is different, the comparator 86 outputs a control signal indicating passage.

Then, at the input 108, the broadcast address and the virtual path identification address VP are "00" and the virtual channel identification address VC is "16" for the terminals 23, 32, 34 and 42 as in the terminal 12.
Information is supplied to the terminals 23, 32, 34, 42 in this order and input
The 120 has information that the broadcast address and VP is “50” and the VC is “27” for the terminal 23, and the broadcast address and VP is “52” for the terminal 32.
Then, the information of which VC is "36" is used for the terminal 34 and the broadcast address and VP.
Is "52" and VC is "38", the broadcast address for the terminal 42 and the information that VP is "54" and VC is "46" are sequentially supplied to the comparator 86.
In this case, since the information is different, the comparator 86 outputs a control signal indicating sequential passage.

Returning to FIG. 2 again, the ATM switch 300 receives the normal ATM cell to be transferred, which is duplicated in the broadcast ATM cell disassembling unit 200, and receives its virtual path identification address VP and virtual channel identification address VC. This is a routing processing unit that routes ATM cells by hardware processing based on a routing bit consisting of, and a buffer type switch or a self-routing type switch such as a batcher-banyan switch or a barrel switch is effectively applied. Output the routed data 12
Output to 4.

The ATM cell assembly unit 400 is the ATM switch 300.
It is an output circuit that assembles cells that have undergone routing processing in 53 bytes into fixed length cells and outputs them to a predetermined route.
A header that generates a 5-byte header section 500 for routing at the next node or generates a 5-byte header section 500 for a terminal accommodated in the own node and adds it to the payload section 600 and outputs it to output 126 It is an additional circuit. In this embodiment, a virtual path identifier (VPI) 502 in which a bit of a broadcast address is added to a bit of a virtual path identification address VP actually used in the own node or another node and a virtual channel identification address VC Bits of the channel identifier (VCI) 504 are arranged in predetermined bits, a payload type 504 and a cell loss priority code 506 are added to this, and a header error control code 508 is further added to generate a header section 500.

The operation will be described. For example, the terminal shown in FIG.
When terminal 12 of the broadcast group consisting of 12, 14, 23, 32, 34, and 42 transmits a broadcast ATM cell to node 10, it transmits the number of terminals in the broadcast group, that is, 6 broadcast ATM cells. . In this case, the terminal
The virtual path identification address (VP) is “00” (own node virtual path identification address) and the virtual channel identification address (VC) is “16” for the predetermined broadcast address assigned to this broadcast group.
The routing bit to which the (virtual channel identification address of the terminal 12) is added is generated, and the broadcast ATM cell in which the payload part 600 is added to the header part 500 including this is transmitted to the node 10.

Then, the broadcast is made from the terminal 12 via the transmission line 16.
The node 10 that receives the ATM cell sends the broadcast ATM cell disassembling unit 20
At 0, the broadcast ATM cell is disassembled and the normality of the cell is confirmed. First, the route information filter 60 sends the received broadcast ATM cell to the address filter 62, separates the virtual path identification address VP of the received broadcast ATM cell, sends it to the relay route information registration table 72, and receives it. Information ATM cell virtual path identifier (VP
I) 502 and virtual channel identifier (VCI) 504 are separated and sent to the route information comparator 86. The relay route information registration table 72 determines whether the sent virtual path identification address (VP) is from the terminal accommodated in the own node or is for relay, that is, from another node. If
Since it is from the terminal accommodated in the own node, the logic level "1" is sent to the control input terminal 126 of the data selector 84.

Subsequently, the address filter 62 sends the sent broadcast ATM cell to the copy buffer 64, and separates the broadcast address in the virtual path identifier (VPI) 502 of the sent broadcast ATM cell. And send it to the broadcast address registration CAM74. The broadcast address registration CAM 74 copies the entry address corresponding to the transmitted broadcast address to the copy control information memory 76.
To the relay route registration memory 78 and the subscriber route registration memory 80. In this case, the entry address sent is
This is effective for the copy control information memory 76 and the subscriber route registration memory 80. The copy control information memory 76 sends information indicating the number of copies according to the sent entry address to the copy control circuit 82. In this case, information indicating the number of 6 copies is sent.

Further, the subscriber route registration memory 80 sends route information corresponding to the sent entry address to the data selector 84 to the data input terminal 134. That is, the subscriber route registration memory 80 receives an entry address having a different address six times each time the node 10 receives a broadcast ATM cell. In this case, the subscriber system route registration memory 80, for the first time, uses the virtual channel identification address VC "1" and the information in which the broadcast address is added to the virtual path identification address VP "00" for the terminal 12.
6 ”information is output, the second time outputs information in which the broadcast address is added to the virtual path identification address VP“ 00 ”for the terminal 14 and the virtual channel identification address VC“ 18 ”, and the third time Information in which the broadcast address is added to the virtual path identification address VP "50" for the terminal 23 and the virtual channel identification address VC
The information of "27" is output, the fourth time outputs the information of the broadcast address added to the virtual path identification address VP "52" and the information of the virtual channel identification address VC "36" for the terminal 32, and the fifth time. Is the virtual path identification address VP "52" for the terminal 34 and the information added with the broadcast address and the virtual channel identification address.
The information of VC "38" is output, and the sixth time outputs the information of the virtual path identification address VP "54" with the broadcast address added and the information of the virtual channel identification address VC "46" for the terminal 42.

Next, the copy control circuit 82 sends a write control signal based on the information indicating the number of copies sent to the copy buffer 64, and the payload part 600 of the payload ATM cell 600 of the broadcast ATM cell sent from the address filter 62. While writing 48 bytes of user data to the buffer 64, a read control signal is sent to the buffer 64 to read the user data written to the buffer 64 and send to the route information adding circuit 68. In this case, each time the node 10 receives the broadcast ATM cell, the write / read operation is performed, that is, 6 times.

Further, the control input terminal 12 of the data selector 84
Since the logic level "1" is sent to 6 as described above, "O" is placed between the data input terminal 134 and the data output terminal 120.
N ”. Therefore, subscriber route registration memory
The above-mentioned six route information read from 80 are sent to the route information giving circuit 68 and the route information comparing circuit 86. The route information adding circuit 68 receives the copied 48-byte user data sent from the copy buffer 64, adds the route information sent from the data selector 84 to it, and sends it to the transmission data control circuit 70. This addition is also performed 6 times in this case.

In parallel with this addition, the route information comparison circuit 86
Is the route information sent from the route information filter 60 every time the node 10 receives a broadcast ATM cell and the node 10 broadcast AT.
Each time M cells are received, the route information sent from the subscriber route registration memory 80 via the data selector 84 is compared, and if the route information is the same, a control signal indicating discard is sent, and a different control signal is sent. If so, a control signal indicating passage is sent to the transmission data control circuit 70. In this case, this comparison is performed 6 times. The first time, the information that the broadcast address is added to the virtual path identification address VP "00" for the terminal 12 from the route information filter 60 and the information of the virtual channel identification address VC "16" and the subscriber route registration memory The information with the broadcast address added to the virtual path identification address VP "00" for the terminal 12 from 80 and the information of the virtual channel identification address VC "16" are compared. In this case, since the information is the same, the comparator 86 A control signal indicating discard is output.

The second time, the terminal 14 from the route information filter 60
The same virtual path identification address VP "00" as the terminal 12 for broadcasting, the information with the broadcast address added, the information of the virtual channel identification address VC "16" and the terminal from the subscriber route registration memory 80.
The information with the broadcast address added to the virtual path identification address VP “00” for 14 and the information of the virtual channel identification address VC “18” are supplied and compared by the comparator 86. In this case, the information is different. Therefore, the comparator 86 outputs a control signal indicating passage.

Also from the third time to the sixth time, the route information filter 60 uses the same virtual path identification address VP "00" as the terminal 12 for the terminals 23, 32, 34 and 42, and the information and virtual The information of the channel identification address VC "16" is sequentially supplied, and the information with the broadcast address added to the VP "50" for the terminal 23 from the subscriber route registration memory 80 and VC "27".
Information for the terminal 32, the information with the broadcast address added to the VP “52”, and the information for the VC “36”, and the information for the terminal 34 with the broadcast address added to the VP “52” and the VC “36”. 38 ”information is the terminal
Information for which a broadcast address is added to VP “54” for 42 and VC
The information “46” is supplied and sequentially compared by the comparator 86. In this case, since the information is different, the control signal indicating passage is sequentially output from the comparator 86.

Next, if the cell data in which the route information is added to the user data sent from the route information adding circuit 68 is from the transmitting terminal of its own node, the transmission data control circuit 70 determines the route. A control signal indicating discarding is input from the information comparator 86 to discard the cell data, and when the cell data is not from the transmitting terminal of the own node, a control signal indicating passing is input and the cell data is transmitted. Pass and send to ATM switch 300. Next, in the ATM switch 300 that has received the valid ATM cell, the virtual path identification address VP and the virtual channel identification address VC used in its own node.
The fixed-length cell is routed based on the bit. Then, it was routed by ATM switch 300.
ATM cells are assembled into fixed length cells of 53 bytes by the ATM cell assembling unit 400 and transferred to a predetermined route.

As described above, according to this embodiment, the route information comparator 86 of the own node is the route to which the broadcast address in the broadcast ATM cell sent from the terminal accommodated in the own node is added. The information is compared with the route information added with the broadcast address sent from the subscriber route registration memory according to this broadcast address, and if they are the same, the user data copied by the copy buffer 64 is used. The transmission data control circuit 70 discards the cell data to which the route information is added, which is sent from the subscriber-side route registration memory by the route information addition circuit 68, and is passed if different. In this way, it is possible to discard the duplicated cell data for the subscriber who originated the broadcast ATM cell and prevent the ATM subscriber from returning the ATM cell to the originating subscriber by a simple circuit system. Therefore, the registration data for screening can be reduced accordingly.

[0059]

As described above in detail, according to the broadcast fixed length cell disassembling apparatus of the present invention, the broadcast address, virtual path identification address and virtual channel identification address are received from the filter means and the first storage means. The received address is compared with each other, the discard control signal is output in the case of the same, and the passage control signal is output in the case of different. Receiving cells, receiving discard or passage control signals from the route information comparing means, discarding received duplicate broadcast fixed length cells when receiving discard control signals, receiving when receiving passage control signals It is configured to have transmission data control means for passing the duplicate broadcast fixed length cell.

In this configuration, both the filtering means and the first storage means accommodate the broadcast address containing the broadcast address to which the terminal accommodated in the same self-node belongs and the address identifying the self-node. When the virtual path identification address and the virtual channel identification address accommodating the address for identifying the terminal accommodated in the own node are sent to the route information comparison means, the route information comparison means is the transmission data control means. A discard control signal is output to and the duplicate broadcast fixed length cell to the terminal accommodated in the own node is discarded. With such a simple circuit system, it is possible to effectively prevent the duplicate broadcast fixed length cell from being returned to the transmitting terminal accommodated in the own node.

[Brief description of drawings]

FIG. 1 is a functional block diagram showing a broadcast ATM cell disassembly unit to which a broadcast communication system of the present invention is applied.

2 is a block diagram showing a communication device to which the broadcast ATM cell disassembling unit of FIG. 1 is applied.

3 is a diagram showing a connection relationship of a connectionless ATM communication system to which the communication device of FIG. 2 is applied.

FIG. 4 is a format diagram showing an ATM cell applied to the connectionless ATM communication system of FIG.

[Explanation of symbols]

10, 20, 30, 40 nodes 12, 14, 22, 23, 24, 32, 34, 42, 43, 44 terminals 60-way information filter 62 Address filter 64 copy buffer 68 Route information addition circuit 70 Transmission data control circuit 72 Relay route information registration table 74 Broadcast address registration CAM 76 Copy control information memory 78 Relay system route registration memory 80 Subscriber route registration memory 82 Copy control circuit 84 Data selector 86 Directions Information Comparator 200 Broadcast ATM cell disassembly unit 300 ATM switch 400 ATM cell assembly department

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Koichi Senda 1-7-12 Toranomon, Minato-ku, Tokyo Inside Oki Electric Industry Co., Ltd. (72) Inventor Shigehiko Ushijima 3-19-2 Nishishinjuku, Shinjuku-ku, Tokyo No. Japan Nippon Telegraph and Telephone Corp. (72) Inventor Katsura Noritake 3-19-2 Nishishinjuku, Shinjuku-ku, Tokyo Nihon Telegraph and Telephone Corp. (56) References JP-A-8-79242 (JP, A) ) JP 5-37547 (JP, A) JP 5-300175 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) H04L 12/28 H04L 12/24 H04L 12 / 26 H04Q 3/00

Claims (2)

(57) [Claims] 1. A header of a message including a broadcast address for identifying a broadcast terminal group, a virtual path identification address for identifying its own node or another node, and a virtual channel identification address for identifying a terminal accommodated in its own node or another node. Receives the added broadcast fixed-length cell from the terminal accommodated in its own node,
In a broadcast fixed length cell disassembling device of connectionless type broadcast communication, which analyzes the routing bit of the header, and sends the broadcast fixed length cell copied to the broadcast terminal group indicated by the broadcast address, the device comprising: A broadcast address to which a terminal accommodated in the own node belongs is accommodated in the broadcast address area, an address for identifying the own node is accommodated in the virtual path identification address area, and a virtual channel identification address area is stored in the virtual channel identification address area. Contains an address for identifying a terminal accommodated in the own node, receives the broadcast fixed length cell from the terminal accommodated in the own node, outputs the received broadcast fixed length cell, and receives the received broadcast fixed length cell. The broadcast address, virtual path identification address and virtual channel identification address of the broadcast fixed length cell are separated and output, and the received broadcast address of the broadcast fixed length cell is received. Filter means for outputting separately, broadcast address registration means for receiving a broadcast address from the filter means and outputting an entry address corresponding to the broadcast address, and each terminal accommodated in the own node belong to The broadcast address of the broadcast group, the virtual path identification address and the virtual channel identification address of each terminal of the broadcast group are accumulated, and the accumulated respective addresses corresponding to the entry addresses from the broadcast address registration means are stored. First storage means for reading, copy control information means for receiving an entry address from the broadcast address registration means, and outputting write and read addresses corresponding to the number of terminals of the broadcast address based on the entry address, Receives broadcast fixed length cells from the filter means, and writes and reads from the copy control information means Buffer means for receiving an address, accumulating, reading and copying the message of the broadcast fixed length cell based on the address, receiving the duplicated message from the buffer means, and receiving the broadcast address and virtual path from the first storage means Route information giving means for receiving an identification address and a virtual channel identification address, multiplexing the received message and each address at a predetermined position and outputting a duplicate broadcast fixed length cell, the filter means and the first storage means A route for receiving a broadcast address, a virtual path identification address, and a virtual channel identification address from each other, comparing the received addresses, and outputting a discard control signal if they are the same, and outputting a passage control signal if they are different. Information comparing means, receiving a duplicate broadcast fixed length cell from the route information adding means,
When the discard or passage control signal is received from the route information comparing means, the received duplicate fixed length cell is discarded when the discard control signal is received, and the received duplicate is received when the passage control signal is received. A broadcast address containing a broadcast address to which a terminal accommodated in the same self-node belongs to from both the filter means and the first storage means. When a virtual path identification address accommodating an address identifying the own node and a virtual channel identification address accommodating an address for identifying a terminal accommodated in the own node are sent to the route information comparing means. Is a broadcast fixed length cell disassembling apparatus, wherein the route information comparing means outputs a discard control signal. 2. The broadcast fixed-length cell disassembling apparatus according to claim 1, wherein the filter means further receives the broadcast fixed-length cell from a terminal accommodated in the own node, and receives the broadcast fixed-length cell. The apparatus further comprises virtual path identification address separating means for separating and outputting the virtual path identification address of the cell, wherein the device further receives the virtual path identification address from the virtual path identification address separating means, and the received virtual path identification address is When the address identifying the own node is indicated, the subscriber control signal is output, and when the address identifying the other node is indicated, the relay control signal is output. Relay route information registration Means, a broadcast address of a broadcast group to which each terminal accommodated in the other node belongs, a virtual path identification address and a virtual channel identification address of each terminal of the own node of the broadcast group. A second address is stored, and each of the stored addresses corresponding to the entry address from the broadcast address registration means is read out.
And a broadcast address, a virtual path identification address and a virtual channel identification address from the first and second storage means, and a subscriber system or relay system control signal from the relay route information registration means. When receiving the subscriber system control signal, each address from the first storage means is output,
Switch means for outputting each address from the second storage means when receiving the relay system control signal, and the broadcast address from the switch means instead of the first storage means, A broadcast fixed length cell disassembling apparatus, characterized in that a virtual path identification address and a virtual channel identification address are input to the route information comparing means.