JPH0662031A - Exchanging device for atm communication - Google Patents

Abstract

PURPOSE:To shorten cell transfer period of time without being influenced by the period of time required for competition control by providing two competition control systems and parallely performing the competition control for two cells within two cell time. CONSTITUTION:Competition control programs including request tables respectively programmed at the CPUs of cell control parts 91-94 simultaneously and parallely perform the competition control relating to the two cells using the two cell time through request signal lines 61-64 and competition control lines 71-74 of two systems respectively for switching circuits 111-144. As a result, the competition control for two cells is performed simultaneously and parallely using the two cell time and the cell transfer time for two cells can be accelerated within a range where it is not shortened for more than the competition control time of one time.

Description

Detailed Description of the Invention

[0001]

The present invention is used in digital information communication. In particular, it relates to a technique for increasing the speed of an ATM (asynchronous transfer mode) switching device.

[0002]

2. Description of the Related Art With the spread of ISDN networks, various digital information communication systems have been put into practical use. Among them, A
TM is an excellent method that can handle any communication information.

A conventional example will be described with reference to FIGS. 14 and 15. FIG. 14 is a block diagram of a conventional device. FIG. 15 is a diagram showing a request table. In FIG. 14, the input ports 2 ₁ to 2 ₄ buffer the arriving cells. In the cell control units 9 _{1 to} 9 ₄ , the VPI (Virtual Pass Identifier) number or V
The destination of the cell is read by the CI (Virtual Channel Identifier) number. Switching circuit 1 _{11-1 44} disposed in the switch circuit 12 is arranged in a matrix, whose main effect is the input port 21 _{to 24} receiving the output port 3 ₁ to 3 ₄ Highway 4 _{1-4 4} and output highway 5 ₁ to 5
₄ to connect the cells and input the cells to the input ports 2 ₁ to 2 ₄ to the output ports 3 _{1 to} 3 ₄ .
In addition, the request signals from the cell control units 9 _{1 to} 9 ₄ are received by the request signal lines 6 _{1 to} 6 ₄ and the contention control signal lines 7 _{1 to} 7 ₄ , and a transfer permission signal (hereinafter, referred to as ack) or transfer for the request signal is received. Deny signal (hereinafter, na
ck). Cell control unit 9 _1-
9 ₄ is the request table 13 shown in FIG.
It is composed of a CPU in which a competition control program including is written. The contention control information is transmitted / received through the request signal lines 6 _{1 to} 6 ₄ and the contention control signal lines 7 _{1 to} 7 ₄ according to the procedure of the contention control program. Request table 13 is a memory for recording a request from the cell controller 9 _to 93 _4, the ack or nack from the switching circuit 1 _{11-1 44} thereto when performing contention control program.

Next, referring to FIG. 16, the input ports 2 ₁ ...
The operation of the _two-4 will be described. FIG. 16 shows the input ports 2 ₁ to 2 _4.
It is a figure which shows operation | movement. Before actually transferring cells from input ports 2 _{1 to} 2 ₄ another input port 2 ₁ at the output destination
In order to avoid contention with cells from ~ 2 _{4 the} request signal lines 6 _{1 to} 6 ₄ and the contention control signal lines 7 _{1 to} 7 in advance.
₄ controls the competition. As shown in FIG. 17, after a request is made at a certain cell time (t = 0), the next cell time (t = 1) is set for the destination cell that does not conflict or the cell for which transmission permission has been obtained by contention control. To send. Thus, at the same time that the cell is transmitted, the request for the transmission cell at the next cell time is sequentially transmitted.

The operation relating to the input port 2 ₁ will be described with reference to FIG. FIG. 17 is a time chart showing the operation of the input port 2 ₁ . A for the sent request
Based on ck and nack, a cell is transmitted in the next cell time in the case of ack, and an empty cell is transmitted in the next cell time in the case of nack. For a cell that has become a nack, this is repeated any number of times until an ack is received.

[0006]

The conventional device is an excellent device having a simple structure because each cell control unit independently performs cell transfer control to realize distributed control. However, since cell transfer control is performed using the cell transfer control program of the procedure described above, even if the cell transfer time can be shortened by using, for example, an ultra-high-speed device or an optical switch, it is possible to perform the advance operation one cell time ago. Competitive control makes speeding up difficult.

Since the cell transfer and the contention control are performed within one cell time, the speed of the changeover switch must be adjusted to the one requiring the time, that is, the time required for the contention control.

An object of the present invention is to provide an ATM switching apparatus which has been made under such circumstances and can shorten the cell time without being affected by the time required for contention control.

[0009]

According to the present invention, there are provided an input port of an incoming cell, a buffer for temporarily accumulating cells arriving at this input port for each input port, and an input highway connected to the output of this buffer. , An output port of a cell to be transmitted, an output highway connected to this output port, a switch circuit interconnecting the output highway and the input highway, and a label of a cell to be output next stored in the buffer And a cell control unit including means for sending a connection request to the switch circuit according to the content of the label, the switch circuit including connection availability information in response to the connection request. The cell control unit further includes means for responding to the control unit, and the cell control unit receives the availability information and takes out the cells stored in the buffer. A switching device of the ATM communications and means for sending to the highway.

Here, a feature of the present invention is that the cell control unit reads the label of one or more cells to be output subsequently, in addition to the label of the cell to be output next. And a means for transmitting the connection request in parallel for a plurality of output cells,
The switch circuit includes means for concurrently responding to the connection request with connection availability information for a plurality of output cells. The switch circuit is preferably a matrix switch circuit.

In this ATM communication switching device, the number of the cells to be output is two, and when the cell control unit receives the connection availability information on the two cells to be output, it is transmitted first. It is desirable to include means for transmitting a cell to be transmitted first if the cell to be transmitted is acceptable.

Alternatively, it is desirable to include means for refraining from transmitting when the connection availability information on the two output cells is received and at least one of the two output cells is rejected.

Alternatively, when the connection availability information on the two output cells is received, if the cell to be transmitted ahead of the two cells is not, the transmission of the cell to be transmitted next is withheld. It is desirable to include means.

Alternatively, it is desirable to include a means for refraining from transmission when the same output port as that of the cell which should not be transmitted first is used even if the cell to be transmitted next is acceptable.

Alternatively, if the same output port as the cell that should be transmitted next is used even if the cell to be transmitted first is not, the cell to be transmitted first is replaced with the cell to be transmitted next. It is desirable to include means for transmitting.

The switch circuit is preferably a self-routing switch.

[0017]

The cell transfer time cannot be shortened without shortening the contention control time. In order to shorten the cell transfer time, the time required for contention control performed at the same timing must be shortened together.

The cell transfer time can be shorter than the contention control time, but even if the shortened cell transfer time is used, the contention control time does not exceed 2 cell transfer time.

Therefore, two competitive control systems are provided, and competitive control for two cells is performed in parallel within two cell time. Therefore, in the case of one system, the competition control for two cells can be simultaneously performed within the time for performing the competition control for one cell. That is, two cells can be transferred within the contention control time for one cell in the case of one system, and the cell transfer time can be shortened within the range of contention control time ≦ 2 cell transfer time in the case of one system. As a result, the speeding up of the switching device for ATM communication is not hindered due to the time required for contention control.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The configuration of the first embodiment of the present invention will be described with reference to FIG. FIG. 1 is a block diagram of a first embodiment device of the present invention.

The present invention is based on the incoming port 2 _{1 of the} incoming cell.
21 _{to 24} and a buffer for temporarily storing cells arriving to the input port 21 _{to 24} for each input port 21 _{to 24,} the input highway ₄₁ to which is connected to the output of the buffer
₄ , the output ports 3 _{1 to} 3 _{4 of} the cell to be sent, and the output highways 5 ₁ to 5 ₁ connected to the output ports 3 _{1 to} 3 _4.
5 ₄ and a switch circuit 12 for mutually connecting the output highways 5 _{1 to} 5 ₄ and the input highways 4 ₁ to 4 ₄ ,
A cell control unit 9 including means for reading the label of the cell to be output next stored in the buffer, and means for sending a connection request to the switch circuit 12 according to the content of the label.
And a _{1-9 4,} the switch circuit 12 includes means responsive to availability information of the connection in response to the connection request to the cell controller 9 _to 93 ₄ to the switching circuit 1 _{11-1 44,} further cell The control units 9 _{1 to} 9 ₄ receive the availability information and take out the cells accumulated in the buffer, and input highways 4 ₁ to _{4 4}
It is an ATM communication switching device including means for sending to an ATM.

A feature of the present invention is that the CPU of the cell control units 9 _{1 to} 9 ₄ reads the label of the cell to be output next, in addition to the label of the cell to be output next. and means, and means for sending the connection request in parallel for two cells of this output, the switching circuit 1 _{11-1 44} of the switch circuit 12 two outputs for this connection request It is to include means for responding parallel connection availability information about the cell. Switch circuit 12 in the present invention the first embodiment device switching circuit 1 _{11-1 44}
Form a matrix switch circuit.

The operation of the first embodiment of the present invention will be described with reference to FIGS.
Will be described with reference to. Figure 2 is a time chart showing an operation of the input port 2 ₁ of the first embodiment of the present invention device. FIG. 3 is a flow chart showing the flow of cells in the device of the first embodiment of the present invention. In Figure 1, the cell controller 9 ₁
9 conflict control program at _four of the CPU includes a programmed request table, the switching circuit 1 _11-1
44 for two cell times used two provided on two by two systems relating to contention control cell request signal line 6 ₁
˜6 ₄ and contention control signal lines 7 _{1 to} 7 ₄ are simultaneously performed in parallel. At this time, as shown in FIG. 3, the cell to be transmitted at the timing of t = 2 is t = 2 of another input port.
Contention control is performed with the cell at the timing. Similarly t
= 3, contention control is performed between cells scheduled to be transmitted at t = 3.

The cell for which nack is returned is sent again as a request at the next timing (t = 2 and 3). With such a configuration, two cells are used for contention control, and two cells are simultaneously operated in parallel, and the cell transfer time for two cells can be speeded up within a range not shortened than one contention control time. The input port 2 ₁ is a FIFO (First-In-
FIRO (First-In-Randam-Out) instead of Firsr-Out)
It is composed of.

FIG. 3 is a flow chart showing the flow of cells. The i-th cell is cell (i), the destination of the i-th cell is D (i), and the ack for the i-th cell is Ack.
(I), (where i = 1, 2, 3, ..., N).
i-th destination cell D (i) and (i + 1) -th destination cell D a request signal (i + 1) is sent to the switching circuit 1 _{11-1 44} corresponding (S1). About D (i) ac
k is received (S2), and D (i + 1) is also acked
Is received (S3), the i-th cell cell
The (i) and i + 1-th cells cell (i + 1) are sent to D (i) and D (i + 1), respectively (S4,
S5). Subsequently, similar competition control is performed for the i + 2nd cell and the i + 3rd cell (S6).

When ack is received for D (i) (S2) but nack is received for D (i + 1) (S3), the i-th cell cell (i) and an empty cell are transmitted (S7, S8). ). Then, the transfer process of the i + 1th cell is performed again, and the competition control of the i + 2nd cell is performed (S9).

Receive a nack for D (i) (S
2), if ack is received for D (i + 1) (S10), empty cell and i + 1th cell cell
(I + 1) is sent to D (i + 1) (S11, S1
2). Then, the transfer process of the i-th cell is performed again, and the competition control of the i + 2nd cell is performed (S13).

Receive a nack for D (i) (S
2), when nack is received for D (i +) (S10), two empty cells are transmitted (S14, S1).
5). Then, the competition control of the i-th cell and the i + 1-th cell is performed again (S16).

Next, the operation of the second embodiment of the present invention will be described with reference to FIGS. Figure 4 is a time chart showing an operation of the input port 2 ₁ of the present invention the second embodiment device. FIG. 5 is a flow chart showing the flow of cells in the device of the second embodiment of the present invention. In FIG. 4, the device configuration is the same as the device of the first embodiment of the present invention. The second embodiment of the present invention is characterized by the CP of the cell control units 9 _{1 to} 9 ₄ .
It is a control procedure of a contention control program including a request table programmed in each U, and performs contention control for two cells, and when either one is nack, both are at cell timings of t = 2 and 3 and both are That is, no cell is transmitted.

The invention The advantage of the second embodiment is that reverse does not occur in the time sequence in a cell of the same VPI number or VCI number assigned to identify the cell, further input ports 2 ₁ - 2 ₄ can be composed of a simple FIFO.

FIG. 5 is a flow chart showing the flow of cells. i-th destination cell D (i) and (i + 1) -th destination cell D a request signal (i + 1) is sent to the switching circuit 1 _{11-1 44} corresponding (S1). Ack is received for D (i) (S2), and a is also received for D (i + 1)
If ck is received (S3), i-th cell cel
The l (i) and i + 1th cells cell (i + 1) are sent to D (i) and D (i + 1), respectively (S
4, S5). Subsequently, similar competition control is performed for the i + 2nd cell and the i + 3rd cell (S6).

When nack is received for either D (i) or D (i + 1) (S2, S
3), 2 empty cells are transmitted (S7, S8). Then, the competition control of the i-th cell and the i + 1-th cell is performed again (S9).

Next, the operation of the third embodiment of the present invention will be described with reference to FIGS. 6 and 7. FIG. 6 is a time chart showing the operation of the input port 2 ₁ in the third embodiment device of the present invention. FIG. 7 is a flow chart showing the flow of cells in the device of the third embodiment of the present invention. In FIG. 6, the device configuration is the same as that of the first and second embodiments of the present invention. It is a feature of the present invention the third embodiment device, cell controller 9 ₁
9 is a control procedure of a contention control program including a request table programmed in each of the CPUs of 9 ₄
When contention control for cells is performed, the i-th cell receives ack, and the i + 1-th cell is nack, only i is transmitted. Here, when the i-th cell becomes nack, The cells after i are not transmitted regardless of ack or nack. When K cells are simultaneously executed in parallel, the data is transmitted up to the place where ack continues, and when there is nack, all the cells thereafter are ack or na.
It is not sent regardless of ck.

An advantage of the third embodiment of the invention is that it preserves the cell order and has the possibility of sending out more cells than the second embodiment of the invention.

FIG. 7 is a flow chart showing the flow of cells. i-th destination cell D (i) and (i + 1) -th destination cell D a request signal (i + 1) is sent to the switching circuit 1 _{11-1 44} corresponding (S1). Ack is received for D (i) (S2), and a is also received for D (i + 1)
If ck is received (S3), i-th cell cel
The l (i) and i + 1th cells cell (i + 1) are sent to D (i) and D (i + 1), respectively (S
4, S5). Subsequently, similar competition control is performed for the i + 2nd cell and the i + 3rd cell (S6).

When ack is received for D (i) (S2) but nack is received for D (i + 1) (S3), the i-th cell cell (i) and an empty cell are transmitted (S7, S8). ). Then, the transfer process of the i + 1th cell is performed again, and the competition control of the i + 2nd cell is performed (S9).

When a nack is received for D (i) (S2), two empty cells are transmitted regardless of the ack or nack of D (i + 1) (S10, S11).
Then, the competition control of the i-th cell and the i + 1-th cell is performed again (S12).

Next, the operation of the fourth embodiment of the present invention will be described with reference to FIG. FIG. 8 is a flow chart showing the flow of cells in the device of the fourth embodiment of the present invention. The time chart showing the operation of the input port 2 _{1 in} the device of the fourth embodiment of the present invention is apparently the same as that of the device of the third embodiment of the present invention shown in FIG. 6, and therefore will be described with reference to FIG. The device configuration of the fourth embodiment of the present invention is the same as that of the first to third embodiments of the present invention. The feature of the device of the fourth embodiment of the present invention lies in the control procedure of the contention control program including the request tables programmed in the CPUs of the cell control units 9 _{1 to} 9 ₄ for performing the contention control for 2 cells. , If the i-th cell is trying to output to the output ports 3 _{1 to} 3 ₄ of the destination of the cell that has become the nack before that, do not send, but if the output ports 3 _{1 to} 3 ₄ are different, send it. Is. This control is controlled by VPI number or VCI numbers rather than the number of output ports 3 ₁ to 3 _4, there permit Received cells are identical to the cells to be transmitted before that V
If it is a PI number or VCI number, it is not sent.

The advantages of the fourth embodiment of the present invention are that the cell order can be preserved, and the mutual interference does not reduce the throughput.

FIG. 8 is a flow chart showing the flow of the cell. i-th destination cell D (i) and (i + 1) -th destination cell D a request signal (i + 1) is sent to the switching circuit 1 _{11-1 44} corresponding (S1). Ack is received for D (i) (S2), and a is also received for D (i + 1)
If ck is received (S3), i-th cell cel
The l (i) and i + 1th cells cell (i + 1) are sent to D (i) and D (i + 1), respectively (S
4, S5). Subsequently, similar competition control is performed for the i + 2nd cell and the i + 3rd cell (S6).

When ack is received for D (i) (S2) but nack is received for D (i + 1) (S3), the i-th cell cell (i) and an empty cell are transmitted (S7, S8). ). Then, the transfer process of the i + 1th cell is performed again, and the competition control of the i + 2nd cell is performed (S9).

Receive a nack for D (i) (S
2), if an ack is received for D (i + 1) and the destination D (i) of the i-th cell and the destination D (i + 1) of the i + 1-th cell are not the same (S10), an empty cell and an i + 1-th cell send cell (i + 1) (S
11, S12). Subsequently, the transfer processing of the i-th cell is performed again, and the competition control of the i + 2nd cell is performed (S
13).

Receive a nack for D (i) (S
2), if the destination D (i) of the i-th cell is the same as the destination D (i + 1) of the i + 1-th cell (S10), the empty cell is set to 2
The cell is transmitted (S14, S15). Then, the competition control of the i-th cell and the i + 1-th cell is performed again (S16).

Next, the operation of the fifth embodiment of the present invention will be described with reference to FIGS. 9 and 10. Figure 9 is a time chart showing an operation of the input port 2 ₁ of the present invention the fifth embodiment apparatus. FIG. 10 is a flow chart showing the flow of cells in the device of the fifth embodiment of the present invention. In FIG. 9, the device configuration is the same as that of the first to fourth embodiments of the present invention. The feature of the device of the fifth embodiment of the present invention lies in the cell control unit 9
_This is a control procedure of a contention control program including a request table programmed in each of the CPUs _{1 to} 9 ₄ and is the same as the destination of the output ports 3 _{1 to} 3 ₄ of the cell which has performed the contention control for 2 cells and has the nack. Ack at the destination
If there is a cell that has received the ACK after that, the cell of that nack is transmitted at the timing when the ack is received later. This makes it possible to improve the probability of transmission while preserving the time sequence.

FIG. 10 is a flow chart showing the movement of cells. i-th destination cell D (i) and (i + 1) -th destination cell D a request signal (i + 1) is sent to the switching circuit 1 _{11-1 44} corresponding (S1). If ack is received for D (i) (S2) and ack is also received for D (i + 1) (S3), i-th cell ce
ll (i) and i + 1th cell cell (i + 1)
To D (i) and D (i + 1) respectively (S
4, S5). Subsequently, similar competition control is performed for the i + 2nd cell and the i + 3rd cell (S6).

When ack is received for D (i) (S2) but nack is received for D (i + 1) (S3), the i-th cell cell (i) and an empty cell are transmitted (S7, S8). ). Then, the transfer process of the i + 1th cell is performed again, and the competition control of the i + 2nd cell is performed (S9).

Receive a nack for D (i) (S
2), ack is received for D (i + 1) (S1
0), and if the destination D (i) of the i-th cell and the destination D (i + 1) of the i + 1-th cell are the same (S11),
The i-th cell cell (i) is transmitted at a timing after the empty cell (S12, S13). Then, the competition control of the i-th cell is performed again, and the competition control of the i + 2nd cell is performed again (S13). If the destination D (i) of the i-th cell and the destination D (i + 1) of the i + 1-th cell are different (S11), then D (i) becomes ack and D (i +
I) cell cel when 1) becomes nack
l (i) is transmitted (S7, S8). Then, i + again
The first and i + 2nd competition control is performed (S9).

Receive a nack for D (i) (S
2), when nack is also received for D (i + 1) (S10), two empty cells are transmitted (S15, S).
16). Then, the competition control of the i-th cell and the i + 1-th cell is performed again (S17).

Next, a sixth embodiment of the present invention will be described with reference to FIG. FIG. 11 is a block diagram of the Burnian switch. A feature of the sixth embodiment of the present invention is that the switching circuits ₁₁ 1 to 1 ₃₄ use the Bernian switch shown in FIG. Switching circuit 1 _{11-1 14,} 1 _{21-1 24,} 1 ₃₁ to the one bit of the header of the cell inputted in each of the ₃₄ is configured to be sent to the read destination.

Next, a seventh embodiment of the present invention will be described with reference to FIG. FIG. 12 is a block diagram of the seventh embodiment of the present invention. The feature of the seventh embodiment device of the present invention is that the cell control unit 9 is integrated. Input ports 21 _{to 24} the identification circuit 11 ₁ to 11 ₄ identifies the cell destination in is provided. The cell control unit 9 is provided with a CPU in which a contention control program including a request table is stored. By the operation of the CPU, contention control and transmission of cells to be transmitted are performed.

Further, the switch circuit 12 can be configured as a self-routing switch 10 as shown in FIG. 12 by using a matrix switch circuit or a Bernian switch.

Next, with reference to FIG. 13, the operation in the case of simultaneously performing the contention control of six cells will be described. FIG.
FIG. 4 is a diagram showing a cell transmission state when contention control of 6 cells is simultaneously performed. In FIG. 13, "○" in the race condition
Means "no conflict" and "x" means "conflict". In the transmission state, “◯” means that the cell is “transmitted”, and “x” means that the cell is “not transmitted”. In addition, in FIG. 13D, "○" and "x"
The alphabets A to F in parentheses represent the types A to F of cells that were transmitted or cells that were not transmitted.

FIG. 13 (a) is similar to the operation of the second embodiment of the present invention, and if the third cell in the transmission order is nack, the other cells have 6 races even if the race condition is ack. Not sent out.

FIG. 13B is similar to the operation of the third embodiment of the present invention, in which cells are transmitted while ack continues from the beginning, but if there is even one nack, No cells are sent.

FIG. 13 (c) is similar to the operation of the fourth embodiment of the present invention, in which contention control for 6 cells is performed, and the destination of the 2nd cell where the 4th cell has been nack before that. If it is trying to output to, it will not be sent. If it is different, it will be sent.

FIG. 13 (d) is similar to the operation of the fifth embodiment of the present invention, in which contention control for 6 cells is performed and ack is received at the same destination as the destination of the second cell for which nack was received. If there is a cell after that, the cell of that nack is transmitted at the timing when ack is received later.

As described above, a plurality of cells can be processed by the same operation.

[0058]

As described above, according to the present invention, the cell time can be shortened without being affected by the time required for contention control.

[Brief description of drawings]

FIG. 1 is a configuration diagram of an apparatus according to a first embodiment of the present invention.

FIG. 2 is a time chart showing the operation of the first embodiment device of the present invention.

FIG. 3 is a flowchart showing the flow of cells in the device of the first embodiment of the present invention.

FIG. 4 is a time chart showing the operation of the second embodiment device of the present invention.

FIG. 5 is a flowchart showing the flow of cells in the device of the second embodiment of the present invention.

FIG. 6 is a time chart showing the operation of the device of the third embodiment of the present invention.

FIG. 7 is a flowchart showing the flow of cells in the device of the third embodiment of the present invention.

FIG. 8 is a flowchart showing the flow of cells in the device of the fourth embodiment of the present invention.

FIG. 9 is a time chart showing the operation of the device of the fifth embodiment of the present invention.

FIG. 10 is a flowchart showing the flow of cells in the device of the fifth embodiment of the present invention.

FIG. 11 is a diagram showing a Burnian switch circuit.

FIG. 12 is a diagram showing a seventh embodiment of the present invention.

FIG. 13 is a diagram showing a cell transmission state when contention control of 6 cells is performed.

FIG. 14 is a configuration diagram of a conventional device.

FIG. 15 is a diagram showing a request table.

FIG. 16 is a diagram showing the operation of the input port.

FIG. 17 is a time chart showing the operation of the conventional device.

[Explanation of symbols]

1 _{11-1 44} switching circuits 21 _{to 24} input port 3 ₁ to 3 ₄ output ports 41 _{to 4} input highways 5 ₁ to 5 ₄ output highway ₆₁ through ₄ request signal line 7 _{1-7 4} contention control Signal line 9, 9 _{1 to} 9 ₄ Cell control unit 10 Self routing switch 11 _{1 to} 11 ₄ Identification circuit 12 Switch circuit 13 Request table

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yukihiro Doi 1-1-6 Uchisaiwaicho, Chiyoda-ku, Tokyo Nihon Telegraph and Telephone Corporation

Claims (8)

[Claims] 1. An input port of an incoming cell, a buffer for temporarily accumulating cells arriving at this input port for each input port, an input highway connected to the output of this buffer, and an output port of a cell for sending out. , An output highway connected to the output port, a switch circuit interconnecting the output highway and the input highway, means for reading the label of the cell to be output next stored in the buffer, A cell control unit including means for sending a connection request to the switch circuit according to the content, and the switch circuit includes a unit for responding to the cell control unit with connection availability information in response to the connection request. Further, the cell control unit receives the availability information, extracts the cells stored in the buffer, and sends the cells to the input highway. In the switching device for ATM communication including, the cell controller includes a unit for reading the label of one or more cells to be output subsequently in addition to the label of the cell to be output next, And a means for transmitting the connection request in parallel to a plurality of cells to be connected, the switch circuit, in response to the connection request, a means for responding parallel connection availability information for a plurality of output cells An ATM communication switching device comprising: 2. The ATM communication switching apparatus according to claim 1, wherein the switch circuit is a matrix switch circuit. 3. The ATM communication switching device according to claim 1, wherein the number of cells to be output is two, and the cell controller receives connection permission / inhibition information about the two cells to be output. At this time, if the cell to be transmitted first is acceptable, the switching device for ATM communication is provided with means for transmitting the cell to be transmitted first. 4. The ATM communication switching device according to claim 1, wherein the number of cells to be output is two, and the cell control unit receives connection permission / inhibition information about the two cells to be output. An ATM communication switching apparatus comprising means for refraining from transmitting if at least one of the two cells is negative. 5. The ATM communication switching device according to claim 1, wherein the number of cells to be output is two, and the cell control unit receives the connection permission / inhibition information about the two cells to be output. , An ATM including means for refraining from transmitting the cell to be transmitted next if there is no cell to be transmitted ahead of the two cells
Communication switching equipment. 6. The ATM communication switching device according to claim 1, wherein the number of cells to be output is two, and the cell control unit transmits the cell to be transmitted first even if the cell to be transmitted next is acceptable. A switching device for ATM communication, comprising means for refraining from transmitting when using the same output port as a cell that has not been used. 7. The switching device for ATM communication according to claim 1, wherein the number of cells to be output is two, and the cell control unit transmits the next cell even if there is no cell to be transmitted first. A switching device for ATM communication, comprising means for transmitting a cell to be transmitted first instead of a cell to be transmitted next when using the same output port as a cell to be transmitted. 8. The ATM communication switching device according to claim 1, wherein said switch circuit is a self-routing switch.