JP2757907B2 - ATM switch and control method thereof - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a one-to-one communication cell for outputting a cell input from one input port to one output port, and a one-to-N communication for duplicating and outputting the cells to a plurality of output ports. ATM (Asynchronous Transmission Multiplexing System) for setting a predetermined priority to the one-to-one communication cell and the one-to-N communication cell to be output to one and the same output port. More particularly, the present invention relates to a switch and a control method thereof, and particularly relates to a shared buffer type one-to-N communication cell in which a buffer corresponding to an output port is formed using one memory.
The present invention relates to an ATM switch capable of processing both cells without lowering the throughput of a switch that processes the cells together with the one-to-one communication cells, and a control method thereof.

[0002]

2. Description of the Related Art Conventionally, in this type of ATM switch, as shown in FIG. 2, input side multiplexing means 11, demultiplexing means 12, output port corresponding buffer 19, and output side The cell path from the output ports # 1 to #N via the multiplexing means 21 is separated from the cell path from the output port # 1 to #N by the separating means 12 and connected to the output-side multiplexing means 21 via the 1-to-N buffer 22 and the duplication means 23. Another cell path is provided. The cell input from one input port is stored in the buffer 19 corresponding to the output port of one path.
One-to-one communication cells that output to two output ports
In the one-to-N correspondence buffer 22 of the other path, cells of one-to-N communication for copying and outputting cells input from one input port to a plurality of output ports are temporarily stored.

The input side multiplexing means 11 comprises input ports # 1 to # 1.
The communication cell input from #N is multiplexed and output to the demultiplexing means 12. The separating means 12 sequentially sorts and separates the input communication cells, and outputs the one-to-one communication cells to the output port corresponding buffer 19 corresponding to each output port, and the one-to-N communication cells to the one-to-N corresponding buffer 22. , And are temporarily stored sequentially.

[0004] The output side multiplexing means 21 is connected to each output port # 1.
The communication cells are taken out of the output port correspondence buffer 19 and the duplicating means 23 corresponding to .about. # N, multiplexed, and output to the corresponding output ports # 1 to #N.
The duplication unit 23 duplicates a plurality of cells corresponding to a plurality of output ports designated for output from the one-to-N communication cells stored in the one-to-N correspondence buffer 22, and Output is made for each output port by access. The copying unit 23 outputs all the copied cells from one cell for one-to-N communication stored in the one-to-N correspondence buffer 22, and then performs the duplication and output processing of the next cell.

At the time of multiplexing on the output side, the output side multiplexing means 21 takes out the one-to-one communication cells of the output port corresponding buffer 19 at a higher priority than the one-to-N communication cells of the duplication means 23. Is controlled. As a result, one-to-one communication cells that can be processed simply with one ground can be processed promptly without stagnation inside the switch, so that one-to-N communication cells have higher priority than one-to-one communication cells. Therefore, the capacity of the buffer may be smaller than that of the first embodiment, and the efficiency of the switch processing may be improved.

[0006]

SUMMARY OF THE INVENTION The conventional ATM described above.
The switch uses the output-side multiplexing means to set the number of cells for one-to-one communication to one.
The priority is set higher than the cell for N-to-N communication. As a result, in a state in which many one-to-one communication cells are concentrated on one output port, one of the output ports of the one-to-N communication cell that is being output from the duplication unit has the concentrated output port. If it is included, the next one-to-N communication cell is stored in the one-to-N correspondence buffer until the next one-to-N communication cell can be output to another output port until the processing of the duplication unit is completed. There is a problem that a state in which it cannot be taken out occurs.

An object of the present invention is to solve the above-mentioned problems by providing an ATM switch capable of processing a cell for one-to-N communication without reducing the throughput of the switch for processing the cell for the one-to-one communication together with the cell for one-to-one communication. The purpose is to provide a control method therefor.

[0008]

An ATM switch and a control method thereof according to the present invention have a plurality of input ports and a plurality of output ports, and a cell input from one input port is paired with a cell for one-to-one communication. ATM that multiplexes and outputs the one-to-one communication cell and the one-to-N communication cell, which are separated into N communication cells and output to the same output port, by setting a predetermined priority order (Asynchronous time-division multiplexing) In a switch and a control method therefor, the separated one-to-N communication cells are separated into high-priority high-priority cells and low-priority low-priority cells, and the one-to-one communication is performed. The priority of the cell is set to a higher priority in the high priority cell and to a lower priority in the low priority cell, and one of the high priority cell and the low priority cell is input. And cell multiplexed with the one-to-one communication side, and outputs multiplexed other on the output side.

The ATM switch according to the present invention has a plurality of input ports and a plurality of output ports, and separates a cell input from one input port into a cell for one-to-one communication and a cell for one-to-N communication. Demultiplexing means, output-side multiplexing means for multiplexing the one-to-one communication cells and one-to-N communication cells output to the same output port, and one-to-N communication output from the demultiplexing means Two 1-to-N buffers for temporarily storing cells by separating cells into high-priority cells with high priority and low-priority cells with low priority, and copying from one of the 1-to-N buffers And the ones output from the separating means.
Intermediate multiplexing means for multiplexing a one-to-one communication cell, wherein a plurality of one-to-N communication cells input to the output-side multiplexing means are copied from the other one of the one-to-N correspondence buffers. Cell.

The control method of this ATM switch is as follows.
The two 1-to-N correspondence buffers are a high-priority buffer for temporarily storing high-priority high-priority cells and a low-priority buffer for temporarily storing low-priority low-priority cells. Among the side multiplexing means, the multiplexing means receiving the input from the high-priority buffer gives priority to the high-priority cell of the 1: N communication, while the multiplexing means receiving the input from the low-priority buffer gives the priority to the low-priority cell of the 1: N communication. Priority is set low.

Further, in one advantageous specific configuration of the ATM switch, the intermediate multiplexing means receives communication cells from the low-priority buffer, and the output multiplexing means receives communication cells from the high-priority buffer. I have.

[0012]

Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a functional block diagram showing an embodiment of the present invention. In the ATM switch shown in FIG.
Input side multiplexing means 11 connected to input ports # 1 to #N,
Separation means 12, priority selection means 13, 1: N high priority buffer 14, high priority duplication means 15, 1: N low priority buffer 1
6, low-priority duplication unit 17, intermediate multiplexing unit 18, output port corresponding buffer 19, and output side multiplexing unit 20 connected to output ports # 1 to #N.

The difference from the conventional configuration is that the 1: N buffer and the copying means are divided into two parts, and the 1: N high-priority buffer 14 and the high-priority copying means 15, and the 1: N
A low-priority buffer 16 and a low-priority duplication unit 17;
Further, a priority selection unit 13 and an intermediate multiplexing unit 18 are additionally provided at the two connection destinations separated by the separation unit 12.

Next, the function and connection of each component will be described with reference to FIG.

The input-side multiplexing means 11 includes input ports # 1 to # 1.
The communication cell input from #N is time-division multiplexed and output to the demultiplexing means 12. The separating means 12 sequentially sorts and separates the input communication cells based on the header information of the cells, and performs the one-to-N communication cells to the priority selection means 13 and the one-to-one communication cells to the intermediate multiplexing means 18. Each is output.

The priority sorting means 13 sorts the received one-to-N communication cells into high-priority cells or low-priority cells according to a predetermined priority.
The N-to-N high-priority buffer 14 has, on the other hand, a one-to-N
It is assumed that they are temporarily stored in the low-priority buffers 16 respectively. The priorities are set based on the header information of each cell and the priority for the header information, and are stored in the priority selection unit 13 in advance.

The high-priority cells stored in the 1-to-N high-priority buffer 14 are extracted by the high-priority duplication unit 15, and the high-priority duplication unit 15 outputs the extracted cells to a plurality of output ports corresponding to a plurality of output ports designated for output. , And the copied cell is taken out by the output side multiplexing means 20. The high-priority duplication unit 15 outputs all cells copied from one cell for one-to-N communication stored in the one-to-N high-priority buffer 14 and then performs duplication and output processing of the next cell.

On the other hand, the low-priority cells stored in the 1-to-N low-priority buffer 16 are extracted by the low-priority duplication unit 17, and the low-priority duplication unit 17 outputs the extracted cells to a plurality of output ports designated for output. To be output to the intermediate multiplexing means 18.

The intermediate multiplexing means 18 time-division multiplexes the one-to-one communication cells received from the demultiplexing means 12 and the one-to-N communication low-priority cells received from the low-priority duplication means 17, and performs an output port corresponding buffer 19 Output to The output port correspondence buffer 19 temporarily stores cells output from the intermediate multiplexing means 18 in the corresponding queue of each output port sequentially.

The output side multiplexing means 20 is connected to each output port # 1
The communication cells are taken out from the output port correspondence buffer 19 and the high-priority duplication unit 15 in correspondence with .about. # N, multiplexed, and output to the corresponding output ports # 1 to #N.

In the above configuration, the intermediate multiplexing means 1
8, the cell of the one-to-one communication from the separating unit 12 is set to a higher priority than the low-priority cell of the one-to-N communication from the low-priority duplicating unit 17.
The high-priority cell of the 1: N communication from the high-priority duplication means 15 is
It is assumed that the priority is set and controlled to be higher than the communication cell from the output port corresponding buffer 19.

In this setting, the priority at the time of simultaneous processing is set to the highest priority cell of one-to-N communication, and then to one-to-one communication.
The communication cell and the remaining low-priority cell of the 1: N communication are set to the lowest. Since the priority of the high-priority cell of the 1: N communication is set higher than that of the cell of the one-to-one communication by the output side multiplexing means 20, the communication cells of the high-priority duplication means 15 and the 1: N high-priority buffer 14 are stored. Are sequentially processed with priority. On the other hand, the communication cell from the output port correspondence buffer 19 is different from the one in which each communication cell copied from the high priority cell of the 1: N communication is sequentially taken out to a different output port. Since only an output port is supported, processing is performed as soon as an empty output port is generated, and the queuing of communication cells in each buffer in the ATM switch is averaged.

On the other hand, since the one-to-one communication cell is given priority in the intermediate multiplexing means 18, while the one-to-one communication cell is being input, the low-priority cell of the one-to-N communication is changed to the low-priority duplication means 17.
And cells are not taken out of the 1-to-N low-priority buffer 16, but there is always a time when there is no cell somewhere in all the input ports, and the separating means 12 removes the cells for 1-to-N communication. The multiplexing is performed by using the idle time.

Further, the output port corresponding buffer 19 includes:
Since a plurality of communication cells generated from the low-priority cells of 1: N communication are superimposed as compared with the related art, cell traffic inside the switch increases, and this increase in traffic is reflected on the input side, and A reduction in traffic occurs, and the processing in the switch for the low priority cell of the 1: N communication is facilitated.

In the above description, priority selection means is provided to
Although the function of selecting the high-priority cell and the low-priority cell for N-to-N communication is explicitly described, the selection may be performed by a separating unit or a 1: N high-priority buffer or a 1: N low-priority buffer. Thus, the allocation of functions, for example, separation / merging, etc., is free as long as the above functions are satisfied, and the above description does not limit the present invention.

Further, in the above description, the high-priority cells for one-to-N communication are multiplexed by the output side multiplexing means, while the low-priority cells for one-to-N communication are multiplexed by the intermediate multiplexing means. Although the internal path was shortened again, the priority control of the output multiplexing unit was made the same as the conventional one, and the priority control of the intermediate multiplexing unit was set to 1
The conventional problem can be solved even if the priority is set to the cell for communication with N, and the low-priority duplication means is connected to the output multiplexing means, and the high-priority duplication means is connected to the intermediate multiplexing means.

[0028]

As described above, according to the present invention, 1
A cell input from one input port is separated into one-to-one communication cells and one-to-N communication cells, and one-to-one communication cells and one-to-N communication output to one and the same output port. When a predetermined priority is set to the cells having the same priority, the separated one-to-N communication cells are further separated into a high-priority high-priority cell and a low-priority low-priority cell. The priority for the cell is set to a higher priority in the high priority cell, and to a lower priority in the low priority cell, and one of the high priority cell and the low priority cell is set at the input side. An ATM switch multiplexing with cells for one-to-one communication and multiplexing and outputting the other at the output side, and a control method therefor are obtained.

According to this configuration / method, both cells can be processed without lowering the throughput of the switch that processes the one-to-N communication cells together with the one-to-one communication cells.
A TM switch and its control method can be obtained.

[Brief description of the drawings]

FIG. 1 is a functional block diagram showing an embodiment of the present invention.

FIG. 2 is a functional block diagram showing an example of the related art.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Input side multiplexing means 12 Separation means 13 Priority selection means 14 1: N high priority buffer (1: N correspondence buffer) 15 High priority duplication means 16 1: N low priority buffer (1: N correspondence buffer) 17 Low priority duplication means 18 Intermediate multiplexing means 19 Output port corresponding buffer 20 Output side multiplexing means

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) H04L 12/56 H04L 12/28 H04Q 11/04

Claims (6)

(57) [Claims] 1. A one-to-one communication cell having a plurality of input ports and a plurality of output ports, and outputting a cell input from one input port to one output port, and a cell input from one input port. The one-to-N communication cell is copied to a plurality of output ports and separated into one-to-N communication cells that are output to the same output port.
In an ATM (Asynchronous Transmission Multiplexing) switch that sets a predetermined priority to a communication cell and multiplexes and outputs the separated cells, the separated one-to-N communication cells are assigned higher priority cells and higher priority cells. And the priority for the one-to-one communication cell is set to a higher priority in the high-priority cell and to a lower priority in the low-priority cell. An ATM switch characterized in that one of the priority cell and the low priority cell is multiplexed on the input side with the one-to-one communication cell, and the other is multiplexed on the output side. A plurality of input ports and a plurality of output ports, wherein one-to-one communication cells for outputting cells input from one input port to one output port and a plurality of cells input from one input port; Separation means for separating the cells into one-to-N communication cells which are duplicated and output to an output port of the one-to-one communication;
In an ATM switch having an output-side multiplexing means for multiplexing a cell for N-to-N communication, a cell for one-to-N communication output from the demultiplexing means is a high-priority cell having a high priority and a low-priority cell having a low priority. Two 1-to-N correspondence buffers for temporarily storing each cell after being separated into cells, a plurality of communication cells taken out of one of the buffers and copied, and one-to-one communication cells output from the separation means Intermediate multiplexing means for multiplexing the one-to-N communication, wherein the cells for one-to-N communication inputted to the output-side multiplexing means are a plurality of communication cells taken out from the other of the one-to-N correspondence buffers and copied. Characteristic ATM switch. 3. The control method for controlling an ATM switch according to claim 2, wherein said two 1-to-N buffers correspond to a high-priority buffer for temporarily storing high-priority high-priority cells and a low-priority low-priority buffer. A low-priority buffer for temporarily storing priority cells, and among the intermediate multiplexing means and the output-side multiplexing means, a multiplexing means receiving an input from the high-priority buffer gives priority to a high-priority cell of 1: N communication,
A control method for an ATM switch, wherein the multiplexing means for receiving an input from the low-priority buffer sets a low priority of low-priority cells in one-to-N communication. 4. The control method for controlling an ATM switch according to claim 2, wherein said intermediate multiplexing means receives a communication cell from said low-priority buffer, and said output-side multiplexing means communicates from a high-priority buffer. A method for controlling an ATM switch, comprising receiving a cell. 5. A one-to-one communication cell having a plurality of input ports and a plurality of output ports for outputting a cell input from one input port to one output port and a plurality of cells input from one input port. ATM switch that multiplexes the one-to-one communication cell and the one-to-N communication cell into the same output port, and multiplexes and outputs them to the same output port. , Input-side multiplexing means for performing time-division multiplexing of cells input from a plurality of input ports and outputting the cells, and one-to-N communication with cells for one-to-one communication by inputting cells output from the input-side multiplexing means Separating means for separating and outputting the cells, a priority selecting means for selecting and outputting the priority of the one-to-N communication cell input from the separating means, and a pair of signals input from the priority selecting means. Temporarily use high priority cell of N communication A high-priority buffer to be stored; a high-priority duplication unit for duplicating cells taken out of the high-priority buffer into cells corresponding to the output ports; and a temporary storage of low-priority cells for one-to-N communication input from the priority selection unit. A low-priority buffer, a low-priority duplication unit for duplicating a cell taken out from the low-priority buffer to a cell corresponding to the output port, and outputting the cell, and a one-to-N communication cell output from the low-priority duplication unit. An intermediate multiplexing means for multiplexing and outputting the one-to-one communication cells output by the separating means, and an output port corresponding buffer for temporarily storing cells output from the intermediate multiplexing means in correspondence with output destination ports, respectively; The one-to-one communication cells stored in the output port-corresponding buffer and the one-to-N communication cells output from the high-priority duplication means are respectively associated with the output port of the output destination. ATM switch, comprising an output-side multiplexing means for multiplexing with. 6. The control method for controlling an ATM switch according to claim 5, wherein said intermediate multiplexing means gives priority to a one-to-one communication cell input from said demultiplexing means, and said output multiplexing means gives said high-precision cell. A method for controlling an ATM switch, wherein priority is given to a cell of one-to-N communication input from a priority duplication unit.