JPH05344143A - Multi-address communication system for atm exchange - Google Patents

Abstract

PURPOSE:To improve efficiency by outputting a cell for one-to-one communication transferred from a switch part on the output side of a housing part as it is, and outputting only the cell to be outputted concerning multi-address communication cells from a cell transfer means for multi-address. CONSTITUTION:The cell for one-to-one communication transferred from a switch part 1 is outputted to a terminal or a transmission line housed in the own housing part 2 as it is by a reception judging means 5 installed on the output side of the housing part 2. Concerning the multi-address communication cell transferred from a multi-address cell transfer means 3, it is judged whether the cell is outputted or not, and only the relevant cell is received and outputted. Therefore, the means 5 is provided with a header table in an output part for storing an identifier to be added to the cell at the time of outputting the cell corresponding to the peculiar identifier for multi-address communication added to the cell for multi-address communication by one-to-one, and a multi-address header transformation part for performing header transformation to the cell for multi-address communication by using the stored contents. Then, header transformation is performed, and the cell for multi-address communication is outputted.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to an asynchronous transfer mode (AT
M) The present invention relates to a communication system using cells, and more particularly to a broadcast (multicast) communication system in an ATM switch for transferring the same cell to a plurality of destinations.

[0002] An ATM exchange for accommodating multimedia accommodates various terminals from low speed terminals to high speed terminals, and not only has a function of simply providing a point-to-point communication path between these terminals, but also CATV and various terminals. Broadcast service (weather forecast, road traffic information, stock price information, etc.)
In order to realize the above on the ATM network, the function of connecting multipoints between the center terminal and the local terminal is required.

[0003]

2. Description of the Related Art As a conventional method for realizing such a function, a hardware switch as shown in FIG. 14 has been devised. This is because multicast is provided by providing a buffer memory at each grid point of the communication path highway arranged in a matrix and controlling the switch operation at each grid point by the distribution control mechanism D provided at the input stage of the switch. ) Is realized.

However, although such a switch can be expanded logically as a building block when the scale is expanded, the electrical characteristics are actually hindered by an increase in the number of fan-outs and the matrix size is increased. Since expansion is difficult, it is necessary to have a configuration in which basic modules are arranged in multiple stages as shown in FIG. In order to realize the multicast function on such an expanded switch configuration, not only a distribution control mechanism is required at the input stage of each basic module, but also the routing control of cells in the switch becomes complicated. I have a problem to say.

On the other hand, as a system that does not depend on the configuration or scale of the switch, as shown in FIG. 16, there is a system in which a cell copying unit is provided outside the switch and is positioned as one service trunk. This is because the cells for which multicast is requested are transferred to the cell copy unit once, copied as many times as necessary for distribution, and replaced with different logical headers (ATM headers). The switch simply realizes multicast equivalently by connecting point-to-point between the service trunk and the terminating local terminal. With such a configuration, it is not necessary to provide a special control function to the switch, and there is an advantage that the multicast can be realized only by the point-to-point basic connection function, but the processing capacity in the cell copying unit becomes a bottleneck, and There is a problem that it becomes difficult to perform multicast to the destination terminal or high-speed communication.

[0006]

SUMMARY OF THE INVENTION It is an object of the present invention to easily realize broadcast communication even when there are a large number of destination terminals, without depending on the scale of the switch or its configuration form.

[0007]

FIG. 1 is a block diagram of the principle configuration of the first invention, and FIG. 2 is a block diagram of the principle configuration of the second invention. These figures show an ATM having a switch unit 1.
A housing unit 2 for housing a terminal or a transmission path for the exchange.
FIG. 3 is a principle block diagram of a broadcast communication system of an ATM cell in an exchange system including a plurality of ATMs.

In FIG. 1, the broadcast cell transfer means 3 is, for example, a slotted ring local area network, and is for transferring broadcast communication cells to be output from a plurality of accommodating units 2.

The cell distribution means 4 is placed on the input side of the accommodation section 2 to the ATM switch, and when the cell inputted from the terminal or the transmission line is the broadcast communication cell, the cell is transferred to the broadcast cell transfer means 3 When the cell is a one-to-one communication cell that is not for broadcast transmission, the cell is output to the switch section 1 of the ATM switch.

The reception judging means 5 is placed on the output side of the exchange of the accommodation section 2, and outputs the one-to-one communication cell transferred from the switch section 1 to the terminal or the transmission line as it is, and the broadcast cell transfer means. As for the broadcast communication cell transferred from No. 3, only the terminal accommodated in the self-accommodating unit or the cell to be output to the transmission path is received and output.

In FIG. 2, the broadcast cell transfer means 6 is shown in FIG.
2 has the same name as the broadcast cell transfer means 3, but in FIG. 2, it is connected to the output side of the switch section of the ATM switch, for example, one output port, and is used for broadcast communication to be output from a plurality of accommodating sections 2. For transferring cells,
For example, the LS as its output port and all accommodating parts (
(Line set)) is a transfer line connecting each of the output sections.

The reception judging means 7 is placed on the output side of the ATM switch of the accommodation section 2 as in the first aspect of the invention, and the one-to-one communication cell directly inputted from the switch section 1 of the switch is the terminal as it is. Alternatively, as for the broadcast communication cell that is output to the transmission path and is input from the broadcast cell transfer means 6, only the terminal accommodated in the self-accommodating unit or the cell to be output to the transmission path is received and output. Is.

[0013]

In FIG. 1 showing the principle of the first invention, the broadcast cell transfer means 3 is, for example, a slotted ring local area network of a type in which cells are placed in empty slots and circulate on a ring. The broadcast communication cell input from the route to the input side of the accommodation unit 2 is transferred to the broadcast cell transfer means 3. On the other hand, the one-to-one communication cell is input from the accommodation unit 2 to the switch unit 1 of the ATM exchange.

The cell distribution means 4 is a means for distributing the cells input to the accommodating portion 2 to either the broadcast cell transfer means 3 or the switch portion 1 and outputting them. The cell distribution means 4 uses, for example, the stored contents of the header table section in the input section that stores the unique identifier for broadcast communication that corresponds to the identifier in the header added to the input broadcast communication cell in a one-to-one manner. In addition, the header conversion unit in the input unit for converting the header of the broadcast communication cell is provided. After this header conversion, the broadcast cell is transferred to the output section of the accommodation section 2 by the broadcast cell transfer means 3 without passing through the switch section 1.

The reception determination means 5 placed on the output side of the accommodation unit 2 outputs the one-to-one communication cell transferred from the switch unit 1 to the terminal accommodated in the own accommodation unit 2 or the transmission line as it is. To be done. Regarding the broadcast communication cell transferred from the broadcast cell transfer means 3, it is judged whether or not the cell accommodated in the self-accommodating section or the cell to be output to the transmission path, and only the corresponding cell is received. Output. Therefore, the reception determination means 5 stores the identifier to be added to the cell when the cell should be output, in one-to-one correspondence with the unique identifier for the broadcast communication added to the cell for broadcast communication. The header table section in the output section and the broadcast call header conversion section for performing header conversion on the broadcast communication cell by using the stored contents are provided for the broadcast communication cell to be output from the own accommodation section. Only the header is converted and the cell is output.

In the second aspect of the invention shown in FIG. 2, any cell is input to the switch section 1 without dividing the broadcast communication cell and the one-to-one communication cell on the input side of the accommodation section 2. The point is different from the first invention. However, for the broadcast communication cell, header conversion is performed using the broadcast communication unique identifier as in the first aspect of the invention, and the broadcast communication cell to which the broadcast communication unique identifier is added is a switch. Part 1
Is transferred to the broadcast cell transfer means 6 connected to one of the output ports. This broadcast cell transfer means 6 is, for example, a connection line connecting its output port and the output side of all the accommodating sections 2, and the broadcast cell from the broadcast cell transfer means 6 and the switch section 1 are connected. The one-to-one communication cell of
In the same manner as in the invention described above, the cell for the one-to-one communication is input to the reception determination means 7 placed on the output side of the accommodating portion 2, and the cell for the broadcast communication is to be output from the self accommodating portion 2 or not. It is determined whether or not a cell to be output is subjected to header conversion, and then output to a terminal or a transmission path.

As described above, according to the present invention, for a cell for broadcast communication, the broadcast cell transfer means is used inside the ATM switching system in a form in which the unique identifier for broadcast communication is added to the cell. Will be transferred.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 3 is a block diagram of an ATM switching system according to an embodiment of the present invention. In the figure, the system corresponds to a switch 10 for exchanging one-to-one communication cells and the broadcast cell transfer means 3 in FIG. 1, and a slot of a system in which a packet type slot constantly circulates on a ring. Ted Ring Local Area Network (LAN)
11, line set (LS) input units 12a to 12d, line set (LS) output units 13a to 13d, and all LS input units and LS output units corresponding to the accommodation unit 2 that accommodates terminals or transmission lines It is composed of a control unit 14 for performing. Although the LS input section and the LS output section are depicted separately in FIG. 3, they are both obtained by extracting the input side and the output side of one line set (LS). One set with the LS output section constitutes one LS.

FIG. 4 is a detailed block diagram of the LS input section of FIG. In the figure, an LS input unit 12 is an ATM interface receiving / terminating unit 20 for physically / electrically terminating a cell input from a terminal or a transmission line, a header converting unit 21 for performing header conversion described later, and a header converting unit. Header table section 22 for storing the contents of 1), a one-to-one communication cell, that is, a normal cell and a broadcast communication cell, that is, a cell distribution control section 23 for distributing a broadcast cell, a normal cell for temporarily storing a normal cell The cell transmission buffer 24, the broadcast cell transmission buffer 25 for temporarily storing the broadcast cell, the switch interface unit 26 for outputting the normal cell to the switch 10, and the slotted ring L for the broadcast cell.
It is composed of a slot access control unit 27 which is placed in an empty slot that circulates on the AN 11.

In FIG. 4, for example, a cell input from a terminal is subjected to processing such as physical / electrical termination and ATM cell level header error check by the ATM interface reception / termination unit 20 and there is no abnormality. Only normal cells are transferred to the header converter 21. The header conversion unit 21 refers to the contents of the header table unit 22 and
The identifier attached to the input cell is converted.

Inside the header table section 22, different contents are stored corresponding to each of the normal cell and the broadcast cell. First, for a normal cell, the switching system sends a transmission line or a terminal in correspondence with the identifiers added to the header of the input cell, for example, the values of the virtual path identifier (VPI) and the virtual channel identifier (VCI). When a cell is output, the value of the identifier (VPI + VCI) to be added to the output cell is stored, and the LS output unit 1 accommodating the terminal or transmission path to which this cell is output
In-switch route information for transferring up to 3 is stored.

On the other hand, for the broadcast cell, the identifier (VPI + V) added to the header of the input cell.
In accordance with the CI), all the LS output units 13a to 13 via the slotted ring LAN 11 in the switching system.
The value of the broadcast cell unique identifier to be added to the cells transferred up to d is stored. This broadcast cell unique identifier is used to identify which user network interface (UN
I) or network node interface (NN
I) an identifier (VPI + VC) that is also not used
I), which is an identifier such as XXX or YYY in FIG.

In the header conversion unit 21, when the input cell is a normal cell, the identifier of the header of the input cell, for example, "1" is converted into a header "A" to be added when the cell is output from the switching system, and a switch is also provided. Inner route information,
For example, "001" is added to the beginning of the cell and sent to the cell allocation control unit 23. In the case of a broadcast cell, for example, the identifier "3" is converted into a broadcast cell unique identifier, for example, "XXX", and then that cell is It is output to the cell allocation control unit 23.
The cell allocation control unit 23 sends normal cells to the normal cell transmission buffer 24 and broadcast cells to the broadcast cell transmission buffer 25, and switches the normal cells stored in the normal cell transmission buffer 24 via the switch interface unit 26. It is output to 10.

On the other hand, the broadcast cell stored in the broadcast cell transmission buffer 25 is placed in an empty slot of the slotted ring LAN by the slot access control unit 27 and output to the slotted ring LAN 11.
The slot access control unit 27 controls slot synchronization of the slotted ring, finds an empty slot, transmits the broadcast cell stored in the broadcast cell transmission buffer 25 to the ring, and When I went around the slotted ring LAN 11 and returned,
The cell either mounts a new cell as it no longer needs to orbit the ring, or it orbits the ring as an empty slot.

FIG. 5 is a detailed block diagram of the LS output section of FIG. In the figure, the LS output unit 13 receives a normal cell from the switch 10, a switch interface unit 30, a broadcast cell receiving unit 31 that receives a broadcast cell from the slotted ring LAN 11, and a broadcast that performs header conversion for the broadcast cell. The call header conversion unit 32, the broadcast call header conversion unit 32 refers to the contents for header conversion, the header table unit 33, the normal cell from the switch interface unit 30, or the broadcast from the broadcast call header conversion unit 32. An output buffer 34 for temporarily storing cells, and an ATM interface transmission terminating unit 35 for outputting the cells stored in the output buffer 34 to a terminal or a transmission line.

In FIG. 5, the normal cell from the switch 10 is transferred to the output buffer 34 via the switch interface section 30. On the other hand, with respect to the broadcast cell from the slotted ring LAN 11, the broadcast cell reception unit 31 takes in the cell, that is, the copy is performed, and the copied cell is output to the broadcast call header conversion unit 32. To be done.

The header table unit 33 stores the value of the identifier (VCI + VPI) to be added to the output cell when the cell is to be output to the terminal or the transmission line, corresponding to the above-mentioned broadcast cell unique identifier. Has been done. When it is not necessary to output the cell, VCI + VPI, that is, an invalid value as the value of the output header, here, "0" is registered corresponding to the broadcast cell unique identifier. Therefore, in the broadcast call header conversion unit 32, when '0' is registered in correspondence with the broadcast cell unique identifier added to the broadcast cell sent from the broadcast cell receiving unit 31, the The cell is discarded, and when a valid value, for example, "5" is registered for "XXX", the "5" is added to the header as an identifier, and the cell is output to the output buffer 34.

6 to 8 are cell allocation control units 23 of FIG.
7 is a flowchart of an example of a distribution process according to the above. FIG. 6 is a flow chart of the first embodiment of the cell allocation processing,
When the processing is started, the identifier stored in the header of the cell sent from the header conversion unit 21 is checked in step (S) 36, and it is determined in S 37 whether the identifier is the broadcast cell unique identifier, If it is the unique identifier, the cell is sent to the broadcast cell transmission buffer in S38, and if it is not the broadcast unique identifier, the cell is sent to the normal cell transmission buffer in S39.

FIG. 7 is a flow chart of the second embodiment of the cell allocation processing. Comparing this figure with the first embodiment of FIG. 6, instead of checking whether or not the identifier of the header is the broadcast unique identifier in S37, that identifier is added to the cell to be output from the switching system in S40. VPI + V
The only difference is that it is determined whether or not it is the value of CI.

FIG. 8 is a flow chart of the third embodiment of the cell allocation process. Comparing this figure with the first embodiment of FIG. 6, whether the processing for checking the identifier of the header is not performed in S36, and whether the in-switch route information is added to the head of the cell sent from the header conversion unit 21 in S41. The difference is that it is determined whether or not.

As described above, according to the present invention, since the multicast cell circulates in the ring, it can be received by all LSs without increasing the traffic, and is unique in the network attached to the cell circling in the ring. Header (XXX, YYY, etc. in the example of FIG. 4) means a broadcast group within a node. Therefore, the control for adding / deleting the terminal (channel) to be transferred in a certain broadcast group may simply instruct the output unit of the LS accommodating the terminal whether or not to perform the above operation. That is, it is realized by the control unit 14 of FIG. 3 controlling the header table of the LS output unit as follows. A cell of a broadcast group (eg YYY)
When transferring to a terminal that has made a transfer request, an empty channel (VPI
+ VCI) and write the value in the header table of the corresponding LS output section. (In the example of FIG. 5, YYY
The value of the output header corresponding to is from "0" to "Hunted V
PI + VCI ”. In one broadcast group (eg ZZZ),
When a disconnection request is issued from a certain terminal, the channel (VPI + VCI) used so far on the interface accommodating the terminal is deleted from the header table of the corresponding LS output unit. (In the example of FIG. 5, the value of the output header corresponding to ZZZ is changed from “6” to “0 (invalid value)”.
Change to. In this way, by updating the header table in the LS output unit that accommodates the terminal that is the target of the transfer request or the disconnection request, the addition / deletion of the broadcast destination can be realized.

9 and 10 are flowcharts of the rewriting process of the header table in the LS input unit and the LS output unit by the control unit of FIG. FIG. 9 shows a flowchart of a process for rewriting the header table in response to a communication request from the terminal. When a communication request from the terminal is detected in step (S) 45, whether or not there is a broadcast communication request in S46. If it is determined that there is no request, the connection destination LS output unit is determined in accordance with the communication request in step S47 as a normal cell transmission request, and the contents of the header table in the LS input unit are created.

When it is determined in S46 that there is a broadcast communication request, it is determined in S48 whether the request is a new request or an additional request, and when it is an additional request, S49.
At S50, the broadcast unique identifier as the broadcast group number for the communication request is determined, and at S50, the LS output unit as an additional connection destination is determined according to the content of the communication request.
The contents of the header table are created in the LS output using the broadcast unique identifier.

If it is determined in S48 that the communication request from the terminal is a new broadcast communication request, the broadcast communication group number, that is, the broadcast communication unique identifier is determined in S51, and S
In 52, the contents of the header table in the LS input section accommodating the terminal that has issued the communication request are created, and in S53, S5
Similar to 0, the contents of the header table in the LS output unit of the connection destination are created.

FIG. 10 is a flowchart for rewriting the header table in response to the disconnection request from the terminal. In the figure, when the communication disconnection request from the terminal is detected in S55, it is determined in S56 whether the communication uses the normal cell or the broadcast cell, and the normal cell is used. In S57, the contents of the header table in the LS input section are deleted in response to the disconnection request in S57.

When it is determined in S56 that the communication uses the broadcast cell, it is determined in S58 whether the communication is partially or completely disconnected. If the communication is partially disconnected, the above-mentioned broadcast communication is performed in S59. The group number is determined, and the content of the header table of the LS output unit is deleted in response to the disconnection request in S60.

When it is determined in S58 that the disconnection request from the terminal is a total disconnection of communication, the broadcast communication group number is determined in S61, and in the LS input section in which the terminal that issued the disconnection request is accommodated. The content of the corresponding header table of is deleted, and the content of the header table of the LS output unit is deleted in S63 as in S60.

FIG. 11 is a configuration block diagram of an embodiment of the ATM switching system according to the second invention. In FIG. 11, one output port of the switch 70 is the LS output unit 7
All of 3a to 73d are connected by a bus-type connecting line for transferring the broadcast communication cells, and the bus-type transfer path corresponds to the broadcast cell transfer means 6 in FIG. Switch 7 from all LS inputs 72a-72d
All broadcast cells input to 0 are output to the output port and input to all the LS output units 73a to 73d.

FIG. 12 is a detailed block diagram of the LS input section in FIG. FIG. 4 is the same as FIG. 4 for the first invention.
Compared with, there is only one cell transmit buffer,
Both the normal communication cell and the broadcast communication cell of the pair 1 are temporarily stored in the cell transmission buffer 83 and output to the switch 70 via the switch interface unit 84. Therefore, the cell distribution control unit and the broadcast cell transmission are performed. The difference is that there is no buffer or slot access control unit. Further, as the storage content of the header table portion, data of the same format as in FIG. 4 is stored for the normal cell, but for the broadcast communication cell, the cell is switched to the switch 70.
To output to a specific output port of
The difference is that the intra-switch route information added to the beginning of the broadcast cell is additionally stored.

FIG. 13 is a detailed block diagram of the LS output section in FIG. FIG. 5 is the same as FIG. 5 for the first invention.
Compared with, the configuration inside the LS output section is exactly the same,
The broadcast cell to the broadcast cell receiver is a slotted ring LA.
Instead of being input from N, it is input only from the broadcast cell transfer port of the switch 70 of FIG.

[0041]

As described above in detail, according to the present invention, it is possible to realize the broadcast communication function without depending on the configuration and scale of the switch, and to realize the slotted ring LAN or the switch. By using the broadcast medium such as the broadcast transfer port on the output side, the cell broadcast communication can be performed without increasing the traffic in the switch even if the destination terminal is added. Furthermore, when adding or deleting a broadcast destination, it can be realized only by updating the contents stored in the header table of the output unit of the line set accommodating the requesting terminal. It greatly contributes to efficiency improvement.

[Brief description of drawings]

FIG. 1 is a block diagram illustrating a principle configuration of a first invention.

FIG. 2 is a block diagram showing a principle configuration of a second invention.

FIG. 3 is a block diagram showing a configuration of an embodiment of an ATM switching system according to the first invention.

FIG. 4 is a block diagram showing a detailed configuration of an LS input unit in FIG.

5 is a block diagram showing a detailed configuration of an LS output unit in FIG.

FIG. 6 is a flowchart of a first embodiment of cell allocation processing.

FIG. 7 is a flowchart of a second embodiment of cell allocation processing.

FIG. 8 is a flowchart of a third embodiment of cell allocation processing.

FIG. 9 is a flowchart of a header table rewriting process embodiment in response to a communication request from a terminal.

FIG. 10 is a flowchart of a header table rewriting process embodiment in response to a communication disconnection request from a terminal.

FIG. 11 is a block diagram showing a configuration of an embodiment of an ATM switching system according to the second invention.

12 is a block diagram showing a detailed configuration of an LS input unit in FIG.

13 is a block diagram showing a detailed configuration of an LS output unit in FIG.

FIG. 14 is a diagram showing a conventional example of a broadcast communication system using a matrix type exchange switch.

FIG. 15 is a diagram showing a conventional example of a broadcast communication system using a multi-stage distribution switch.

FIG. 16 is a diagram showing a conventional example of a broadcast communication system using a cell copying unit.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 switch part 2 accommodating part 3,6 broadcast cell transfer means 5,7 reception determination means 10,70 switch 11 slotted ring LAN 12a-12d, 72a-72d LS input part 13a-13d, 73a-73d LS output part 14 , 74 Control unit

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI Technical indication H04Q 11/04 9076-5K H04Q 11/04 R

Claims (8)

[Claims] 1. An ATM switching system having a plurality of accommodating units (2) accommodating terminals or transmission lines for an ATM switch having a switch unit (1), wherein the plurality of accommodating units (2) output the data. Broadcast cell transfer means (3) for transferring a desired broadcast communication cell, and a cell input from a terminal or a transmission line on the input side of the accommodation section (2) to the exchange is for broadcast communication. A cell that outputs the cell to the broadcast cell transfer means (3) when it is a cell, and outputs the cell to the switch section (1) of the ATM switch when it is a one-to-one communication cell that is not for broadcast communication. The one-to-one communication cell transferred from the switch section (1) at the distribution section (4) and the output side of the accommodating section (2) is directly output to the terminal or the transmission line, and the broadcast cell transfer section is provided. For the broadcast communication cell transferred from (3), A broadcast communication system in an ATM switch, comprising: a terminal accommodated in (2) or a reception determination means (5) for receiving and outputting only cells to be output to a transmission path. 2. A header in an input section in which the cell allocating means (4) stores a unique identifier for broadcast communication which corresponds to the identifier in the header added to the inputted broadcast communication cell in a one-to-one correspondence. A table section and an input section internal header conversion section for performing header conversion for the broadcast communication cell using the stored contents of the header table section, wherein the reception determination means (5) uses the broadcast communication unique identifier The header conversion of the broadcast cell is performed by using the header table section in the output section that stores the identifier to be added at the time of outputting the broadcast cell in a one-to-one correspondence, and the stored content of the header table section. The broadcast communication system in an ATM exchange according to claim 1, further comprising a broadcast call header conversion unit. 3. A control unit for rewriting the contents of the header table in the input unit and the header table in the output unit according to addition / deletion of a containing unit to which the broadcast cell is to be output. A broadcast communication system in an ATM exchange according to item 2. 4. The broadcast cell transfer means (3) is composed of a slotted ring local area network (LAN) having a fixed slot length, and the cell distribution means (4) is the slotted ring LA.
2. The broadcast communication system in an ATM switch according to claim 1, further comprising a slot access control unit for accessing N. 5. An ATM switching system having a plurality of accommodating parts (2) for accommodating terminals or transmission lines for an ATM exchange having a switch part (1), wherein the switch part (1) of the ATM switch is provided. Broadcast cell transfer means (6) connected to the output side for transferring broadcast communication cells to be output from a plurality of accommodating units, and the exchange side at the output side of the exchange in the accommodating unit (2). The one-to-one communication cell directly input from the switch unit (1) is directly output to the terminal or the transmission path, and the broadcast communication cell input from the broadcast cell transfer means (6) is A broadcast communication system in an ATM exchange, comprising: a terminal accommodated in an accommodating section or a reception determination means (7) for receiving and outputting only cells to be output to a transmission path. 6. A broadcast communication specific one-to-one correspondence to an identifier in a header added to a broadcast communication cell to be input on the input side of the accommodation unit (2) to the ATM switch. An input section internal header table section for storing an identifier, and an input section internal header conversion section for performing header conversion on a broadcast communication cell using the stored content of the header table section, wherein the reception determination means (7) is provided. , An internal header table unit in the output unit that stores an identifier to be added at the time of output of the broadcast communication cell in a one-to-one correspondence with the broadcast communication unique identifier, and the same content is stored using the stored contents of the header table unit. 6. A broadcast communication system in an ATM exchange according to claim 5, further comprising a broadcast call header conversion unit for converting a header for a broadcast communication cell. 7. A control unit is provided for rewriting the contents of the header table in the input unit and the header table in the output unit according to addition / deletion of an accommodating unit for outputting the broadcast cell. A broadcast communication system in an ATM exchange according to claim 6. 8. The broadcast cell transfer means (6) is constituted by a connecting line connecting one output port of the switch section (1) and each of the output sections of all the accommodating sections (2). 6. A broadcast communication system in an ATM exchange according to claim 5, wherein: